Journal articles on the topic 'Lifetimes intercalation'
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1
Adonkin, V. T., B. M. Gorelov, V. V. Dyakin, I. I. Karpov, and G. P. Prikhod'ko. "Effect of intercalation and exfoliation on positron annihilation lifetimes in graphites." Journal of Physics and Chemistry of Solids 55, no. 5 (May 1994): 443–46. http://dx.doi.org/10.1016/0022-3697(94)90171-6.
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Jasińska, Bożena, Monika Śniegocka, Renata Reisfeld, and Elena Zigansky. "Temperature and Pressure Measurements of PALS Spectra in Photonic Glasses." Materials Science Forum 607 (November 2008): 166–68. http://dx.doi.org/10.4028/www.scientific.net/msf.607.166.
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The subject of investigation was porous glass produced using a sol-gel technique. ortho-Ps lifetimes and intensities in the material were determined as a function of temperature and pressure. Temperature was ranged from 100 to 500 K while the pressure from 0 to 1200 MPa. Nitrogen gas intercalation into pore structure was observed up to 100 MPa.
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Shimomura, Osamu, Hideki Kusu, Atsushi Ohtaka, and Ryôki Nomura. "DBU-Intercalated α-Zirconium Phosphates as Latent Thermal Catalysts in the Reaction of Hexamethylene Diisocyanate and Phenol." Catalysts 11, no. 5 (May 11, 2021): 614. http://dx.doi.org/10.3390/catal11050614.
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The catalytic activity of 1,8-diazabicyclo [5,4,0]undec-7-ene-intercalated α-zirconium phosphates (α-ZrP·DBU) as thermal latent catalysts in the reaction of hexamethylene diisocyanate (HDI) and phenol was investigated. α-ZrP intercalation compounds with varying amounts of DBU (α-ZrP·xDBU, where x = 0.58, 0.44, 0.22, and 0.10) were prepared. The reaction of HDI and phenol with α-ZrP·DBU was carried out at varying temperatures for 30 min periods. The α-ZrP·DBU showed high catalytic activity in the reaction of HDI-phenol under heating conditions. The α-ZrP·DBU extended the pot lifetimes at 25 °C.
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Liu, Yixian, J. A. Koningstein, and Y. Yevdokimov. "Relative cross section and time-resolved fluorescence of porphyrin–DNA complexes." Canadian Journal of Chemistry 69, no. 11 (November 1, 1991): 1791–95. http://dx.doi.org/10.1139/v91-263.
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Relative values have been obtained for the cross section of fluorescence of tetrakis(4-N-methylpyridyl)porphine and the zinc(II) complex with DNA. Time-resolved fluorescence spectra have been used to assign fluorescence of porphyrins which intercalate at or are externally bound to DNA. The experimental data suggest that an equilibrium distribution for intercalated and externally groove-bound to DNA of porphyrin is reached for [Formula: see text] complexes. Radiative lifetimes of the various porphyrin species have been determined and evidence is found suggesting the contribution of non-linear effects to the intensity of laser induced fluorescence of r > 1000 complexes. Key words: cross section, fluorescence, porphyrin–DNA complexes, intercalation, outside bound.
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Zhang, Wenjun, Yi Chen, Yanlin Li, Sumin Guan, Yan Chen, Qian-Qian Yang, Lu Liu, Qing-Chen Xue, and Yu-Cui Guang. "Intercalation of Europium Inclusion Complex of β-Cyclodextrin into Layered Double Hydroxides Through Layer-By-Layer Assembly and Its Luminescent Properties." Nano 12, no. 10 (October 2017): 1750126. http://dx.doi.org/10.1142/s1793292017501260.
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In this work, organic–inorganic hybrid ultrathin transparent films (UTFs), produced by layer-by-layer (LBL) assembly of the europium inclusion complex of [Formula: see text]-cyclodextrin ([Formula: see text]-CD) and Mg–Al-layered double hydroxide (MgAl–NO3–LDHs) nanosheets, are reported. UV-visible (UV-Vis) absorption and fluorescence spectroscopy show orderly growth of the europium inclusion complex of [Formula: see text]-CD/layered double hydroxide (EICC/LDH) films with an increasing number of deposition cycles. X-ray diffraction and scanning electron microscopy measurements indicate that the films feature periodic layered structures with uniform surface morphology. Moreover, when EICC is assembled with inorganic rigid LDH nanosheets, the lifetimes are prolonged due to the isolation effect, and the UTFs are transparent with high brightness, which indicate that these films could serve as new optical materials.
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Doll, G. L., and P. C. Eklund. "In situ optical and structural studies of H2 chemisorption in C8K." Journal of Materials Research 2, no. 5 (October 1987): 638–44. http://dx.doi.org/10.1557/jmr.1987.0638.
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Results of in situ optical (reflectance, Raman scattering) and 00l x-ray diffraction studies of hydrogen chemisorption in Grafoil-based stage 1 C8K intercalation compounds are presented. Upon hydrogen uptake, stage 2 KC8H2/3 was found to coexist with C8K forming first in the optical skin depth. The intensities of the 00l x-ray diffraction peaks show quantitatively that the reaction C8K + 1/2xH2 ⇉ (1 − 3/2x)C8K + 3/2xC8KH2/3 occurs for x>0.4 in the bulk. The effects of the surface morphology of Grafoil on the near-normal incidence reflectance was investigated and found to be described by an energy (E) dependent function S(E) = exp[−aEn], such that the corrected spectrum Rc = SR, where R is the Grafoil reflectance. In this manner, reflectance spectra of C8K-Grafoil and C8KH2/3-Grafoil were quantitatively analyzed to determine the free carrier contribution. The free carrier lifetimes were found to be a factor of 2 shorter in Grafoil-based hosts, compared to highly oriented pyrolytic graphite-based hosts. The optical results for C8KH2/3 indicate the H(ls) band is full (or very nearly full).
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Cisternas, Marcelo A., Francisca Palacios-Coddou, Sebastian Molina, Maria Jose Retamal, Nancy Gomez-Vierling, Nicolas Moraga, Hugo Zelada, Marco A. Soto-Arriaza, Tomas P. Corrales, and Ulrich G. Volkmann. "Dry Two-Step Self-Assembly of Stable Supported Lipid Bilayers on Silicon Substrates." International Journal of Molecular Sciences 21, no. 18 (September 17, 2020): 6819. http://dx.doi.org/10.3390/ijms21186819.
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Artificial membranes are models for biological systems and are important for applications. We introduce a dry two-step self-assembly method consisting of the high-vacuum evaporation of phospholipid molecules over silicon, followed by a subsequent annealing step in air. We evaporate dipalmitoylphosphatidylcholine (DPPC) molecules over bare silicon without the use of polymer cushions or solvents. High-resolution ellipsometry and AFM temperature-dependent measurements are performed in air to detect the characteristic phase transitions of DPPC bilayers. Complementary AFM force-spectroscopy breakthrough events are induced to detect single- and multi-bilayer formation. These combined experimental methods confirm the formation of stable non-hydrated supported lipid bilayers with phase transitions gel to ripple at 311.5 ± 0.9 K, ripple to liquid crystalline at 323.8 ± 2.5 K and liquid crystalline to fluid disordered at 330.4 ± 0.9 K, consistent with such structures reported in wet environments. We find that the AFM tip induces a restructuring or intercalation of the bilayer that is strongly related to the applied tip-force. These dry supported lipid bilayers show long-term stability. These findings are relevant for the development of functional biointerfaces, specifically for fabrication of biosensors and membrane protein platforms. The observed stability is relevant in the context of lifetimes of systems protected by bilayers in dry environments.
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Chirvony, Vladimir S. "Primary photoprocesses in cationic 5,10,15,20-meso-tetrakis(4-N-methylpyridiniumyl)porphyrin and its transition metal complexes bound with nucleic acids." Journal of Porphyrins and Phthalocyanines 07, no. 11 (November 2003): 766–74. http://dx.doi.org/10.1142/s108842460300094x.
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Photophysical properties of meso-tetrakis(4-N-methylpyridiniumyl)porphyrin ( TMpyP 4) and its metallocomplexes M (II) TMpy P4 ( M = Zn , Cu , Ni , Co ) bound to natural DNA and synthetic poly-, oligo- and mononucleotides are considered with a primary emphasis placed upon intermolecular interaction of the photoexcited porphyrins with the nearest environment. Quenching of the fluorescent S 1 (but not triplet T 1) state due to guanine to porphyrin electron transfer is observed for TMpyP 4 intercalated between GC base pairs of the double-strand helixes, whereas in the case of TMpyP 4 complexed with guanosine monophosphate (GMP) both S 1 and T 1 states of the porphyrin are quenched. Furthermore, a dependence of the efficiency of TMpyP 4 triplet state quenching by the dissolved molecular oxygen from air on the porphyrin localization enables one to readily distinguish porphyrin groove binding mode from intercalation. Excited states of the TMpyP 4 complexes with transition metals, in spite of their very short lifetimes, also interact with nucleic acid components by means of an axial ligand binding/release to/from the metal. A possible structure of the five-coordinate excited complex (“exciplex”) formed in case of CuTMpyP 4 groove binding to some single- and double-strand polynucleotides is discussed.
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Gordon, Leo W., Jian Zhang, Juchen Guo, and Robert J. Messinger. "Understanding Improved Lifetimes of Lithium-Metal Batteries with LiPF6 Carbonate Electrolyte Modified By Phosphorus Pentoxide." ECS Meeting Abstracts MA2022-02, no. 4 (October 9, 2022): 488. http://dx.doi.org/10.1149/ma2022-024488mtgabs.
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Lithium metal anodes offer the possibility of a ten-fold increase in capacity versus standard intercalation anodes such as graphite. However, to date, there has been limited success using commercially available liquid electrolytes for batteries with lithium metal anodes. A critical issue in LiPF6 carbonate electrolytes results from the reaction of trace water (<100 ppm) with PF5, which is in equilibrium with the PF6 - anion, to produce hydrofluoric acid (HF) and difluorophosphoric acid. These reaction products contribute to lithium passivation, transition-metal leaching and subsequent particle cracking at the cathode, and degradation of cell components. Furthermore, HF begins an autocatalytic degradation cycle, so if not removed, can continually decompose the carbonate solvents in a self-sustaining cycle. Here, we demonstrate the effectiveness of a simple and scalable modification procedure of 1M LiPF6 ethylene carbonate (EC)/diethylcarbonate (DEC) (50/50 v/v) electrolyte to greatly enhance performance of lithium-metal batteries. Phosphorus pentoxide (P2O5) added to commercial, battery-grade electrolyte performs the dual functions of both scavenging HF and H2O, while also generating chemical species that promote formation of a beneficial, POxFy-rich SEI layer upon cycling. In commercial-scale pouch cells (0.4 Ah), performance using the modified electrolyte is vastly superior, with 87.7% capacity retention at >230 cycles and minimal hysteresis, to that of the cell with as-received electrolyte, which failed after approximately 30 cycles. Electrodes harvested after 30 cycles in the commercial electrolyte yielded cracked cathode particles and transition metal migration to the anode surface, while these were not seen with the modified electrolyte, corroborating the performance enhancement resulting from HF scavenging. Rigorously quantitative, liquid-state 19F, 31P, 1H, and 13C NMR of the modified electrolyte proves complete removal of residual HF in addition to revealing a plethora of new fluorophosphate species, while two-dimensional 19F{31P} correlation experiments were used to confidently establish signal assignments. These fluorophosphate moieties make up the anodic surface layer that promotes smooth and uniform lithium electrodeposition, further enhancing performance. Understanding the relationship between electrolyte speciation and electrochemical performance is crucial for careful design of electrolyte additives, and in particular, multi-functional materials such as P2O5 offer simple but highly effective improvements to resultant electrolyte formulations. Overall, we achieve enhanced operation of lithium-metal batteries using a P2O5-modified LiPF6 carbonate electrolyte as a result of HF and H2O removal, alongside formation of favorable SEI-forming species. Through NMR, we quantitatively established speciation of this electrolyte to better understand the improved performance and elucidate the major reaction pathways. Reference: Zhang, J., et al. Performance Leap of Lithium Metal Batteries in LiPF6 Carbonate Electrolyte by a Phosphorus Pentoxide Scavenger. (Under review, 2022)
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Besli, Muenir M., Saravanan Kuppan, Sharon E. Bone, Sami Sainio, Sondra Hellstrom, Jake Christensen, and Michael Metzger. "Performance and Lifetime of Battery Desalination Cells Based on Nickel Hexacyanoferrate." ECS Meeting Abstracts MA2022-01, no. 1 (July 7, 2022): 142. http://dx.doi.org/10.1149/ma2022-011142mtgabs.
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Prussian blue analogs, e.g., nickel hexacyanoferrate, NiFe(CN)6 or NiHCF, are promising candidates as low-cost and high-rate intercalation materials for secondary batteries.1–4 Recently, this material class has been shown to possess tremendous potential for a novel energy-efficient water desalination approach.5–8 Rising water demands are exacerbating water scarcity in many world regions. It is estimated that 60% of the global population will face severe water scarcity by 2025.9 The growing water demand necessitates new desalination technologies with high energy efficiency, low capital and operating cost and high freshwater output. In this work, we assess the performance and lifetime of electrochemical water desalination cells based on sodium intercalation into nickel hexacyanoferrate.10–12 The battery desalination cells feature a symmetric design, with two NiHCF electrodes at opposite state-of-charge (SOC), capable of intercalating Na+-ions into their crystal structure. The electrodes are separated by an anion exchange membrane, a porous functionalized polyether ether ketone (PEEK) membrane, that only permits negatively charged ions, e.g., Cl--ions, to pass. Two feed water streams with 20 mM NaCl enter the symmetric cell on either side (see Figure 1a). During charge of the symmetric cell, incoming Na+-ions are removed from one water stream and intercalated into the NiHCF electrode at low SOC. Simultaneously, Na+-ions are deintercalated from the opposite NiHCF electrode at high SOC. In order to maintain charge neutrality, Cl--ions cross the anion exchange membrane. Thus, during every charge/discharge cycle, one water stream is desalinated forming a freshwater stream, while the other is enriched in NaCl forming a brine waste stream (see Figure 1b). In order to quantify performance and lifetime of the novel battery-type water desalination cells, we define and measure objective metrics. We see that energy consumption (Wh/l) and productivity (l/h/m2) of NiHCF/NiHCF cells are superior to cells based on membrane capacity deionization (mCDI). Stable charge/discharge cycling of NiHCF/NiHCF cells can be achieved for over 500 cycles with NaCl feed water, but rapid aging is observed with CaCl2 feeds. Synchrotron-based characterization of NiHCF/NiHCF cells is used to elucidate the reason for capacity fade. X-ray absorption spectroscopy and X-ray fluorescence spectroscopy reveal Fe dissolution from the NiHCF active material as a primary aging mode with CaCl2 water feeds. References Wessells, C. D., Peddada, S. V., Huggins, R. A. & Cui, Y. Nickel hexacyanoferrate nanoparticle electrodes for aqueous sodium and potassium ion batteries. Nano Lett. 11, 5421–5425 (2011). Wessells, C. D. et al. Tunable reaction potentials in open framework nanoparticle battery electrodes for grid-scale energy storage. ACS Nano 6, 1688–1694 (2012). Pasta, M. et al. Full open-framework batteries for stationary energy storage. Nat. Commun. 5, 1–9 (2014). Firouzi, A. et al. Monovalent manganese based anodes and co-solvent electrolyte for stable low-cost high-rate sodium-ion batteries. Nat. Commun. 9, (2018). Pasta, M., Wessells, C. D., Cui, Y. & La Mantia, F. A desalination battery. Nano Lett. 12, 839–843 (2012). Lee, J., Kim, S. & Yoon, J. Rocking Chair Desalination Battery Based on Prussian Blue Electrodes. ACS Omega 2, 1653–1659 (2017). Kim, T., Gorski, C. A. & Logan, B. E. Low Energy Desalination Using Battery Electrode Deionization. Environ. Sci. Technol. Lett. 4, 444–449 (2017). Porada, S., Shrivastava, A., Bukowska, P., Biesheuvel, P. M. & Smith, K. C. Nickel Hexacyanoferrate Electrodes for Continuous Cation Intercalation Desalination of Brackish Water. Electrochim. Acta 255, 369–378 (2017). Jones, E., Qadir, M., van Vliet, M. T. H., Smakhtin, V. & Kang, S. mu. The state of desalination and brine production: A global outlook. Sci. Total Environ. 657, 1343–1356 (2019). Metzger, M. et al. Techno-economic analysis of capacitive and intercalative water deionization. Energy Environ. Sci. 13, 1544–1560 (2020). Sebti, E. et al. Removal of Na+ and Ca2+ with Prussian blue analogue electrodes for brackish water desalination. Desalination 487, (2020). Besli, M. M. et al. Performance and lifetime of intercalative water deionization cells for mono- and divalent ion removal. Desalination 517, 115218 (2021). Figure 1. (a) Battery-type water desalination approach in symmetric NiHCF/NiHCF cells with two salt water streams entering the cell and a brine stream and freshwater stream exiting the cell. (b) During galvanostatic charge/discharge cycling the salt concentrations of brine and freshwater stream can be monitored with microfluidic operando conductivity probes to determine important performance metrics. Figure 1
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Savić, Aleksandar, Anna M. Kaczmarek, Rik Van Deun, and Kristof Van Hecke. "DNA Intercalating Near-Infrared Luminescent Lanthanide Complexes Containing Dipyrido[3,2-a:2′,3′-c]phenazine (dppz) Ligands: Synthesis, Crystal Structures, Stability, Luminescence Properties and CT-DNA Interaction." Molecules 25, no. 22 (November 13, 2020): 5309. http://dx.doi.org/10.3390/molecules25225309.
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In order to create near-infrared (NIR) luminescent lanthanide complexes suitable for DNA-interaction, novel lanthanide dppz complexes with general formula [Ln(NO3)3(dppz)2] (Ln = Nd3+, Er3+ and Yb3+; dppz = dipyrido[3,2-a:2′,3′-c]phenazine) were synthesized, characterized and their luminescence properties were investigated. In addition, analogous compounds with other lanthanide ions (Ln = Ce3+, Pr3+, Sm3+, Eu3+, Tb3+, Dy3+, Ho3+, Tm3+, Lu3+) were prepared. All complexes were characterized by IR spectroscopy and elemental analysis. Single-crystal X-ray diffraction analysis of the complexes (Ln = La3+, Ce3+, Pr3+, Nd3+, Eu3+, Er3+, Yb3+, Lu3+) showed that the lanthanide’s first coordination sphere can be described as a bicapped dodecahedron, made up of two bidentate dppz ligands and three bidentate-coordinating nitrate anions. Efficient energy transfer was observed from the dppz ligand to the lanthanide ion (Nd3+, Er3+ and Yb3+), while relatively high luminescence lifetimes were detected for these complexes. In their excitation spectra, the maximum of the strong broad band is located at around 385 nm and this wavelength was further used for excitation of the chosen complexes. In their emission spectra, the following characteristic NIR emission peaks were observed: for a) Nd3+: 4F3/2 → 4I9/2 (870.8 nm), 4F3/2 → 4I11/2 (1052.7 nm) and 4F3/2 → 4I13/2 (1334.5 nm); b) Er3+: 4I13/2 → 4I15/2 (1529.0 nm) c) Yb3+: 2F5/2 → 2F7/2 (977.6 nm). While its low triplet energy level is ideally suited for efficient sensitization of Nd3+ and Er3+, the dppz ligand is considered not favorable as a sensitizer for most of the visible emitting lanthanide ions, due to its low-lying triplet level, which is too low for the accepting levels of most visible emitting lanthanides. Furthermore, the DNA intercalation ability of the [Nd(NO3)3(dppz)2] complex with calf thymus DNA (CT-DNA) was confirmed using fluorescence spectroscopy.
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Sailer, Brian L., Anthony J. Nastasi, Joseph G. Valdez, John A. Steinkamp, and Harry A. Crissman. "Differential Effects of Deuterium Oxide on the Fluorescence Lifetimes and Intensities of Dyes with Different Modes of Binding to DNA." Journal of Histochemistry & Cytochemistry 45, no. 2 (February 1997): 165–75. http://dx.doi.org/10.1177/002215549704500203.
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Deuterium oxide (D2O) increases both the fluorescence lifetime and the fluorescence intensity of the intercalating dyes propidium iodide (PI) and ethidium bromide (EB) when bound to nucleic acid structures. We have used spectroscopic analysis coupled with conventional and phase-sensitive flow cytometry to compare the alterations in intensity and lifetime of various DNA-binding fluorochromes bound to DNA and Chinese hamster ovary (CHO) cells in the presence of D2O vs phosphate-buffered saline (PBS). Spectroscopic and flow cytometric studies showed a differential enhancement of intensity and lifetime based on the mode of fluorochrome-DNA interaction. The fluorescence properties of intercalating probes, such as 7-aminoactinomycin D (7-AAD) and ethidium homodimer II (EthD II) were enhanced to the greatest degree, followed by the probes TOTO and YOYO, and the non-intercalating probes Hoechst 33342 (HO) and 4',6-diamidino-2-phenylindole (DAPI). The non-intercalating probe mithramycin (MI) gave unexpected results, showing a great enhancement of fluorescence intensity and lifetime in D2O, indicating that when staining is performed in PBS, much of the MI fluorescence is quenched by the solvent environment. Apoptotic subpopulations of HL-60 cells had a shorter lifetime compared to nonapoptotic subpopulations when stained with EthD II. These results indicate that accessibility of the dye molecules to the solvent environment, once bound to DNA, leads to the differential enhancement effects of D2O on fluorescence intensity and lifetime of these probes.
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Zgardzińska, Bożena, Tomasz Goworek, and Jan Wawryszczuk. "Positronium in Alkanes at High Pressure of Argon and Nitrogen." Materials Science Forum 607 (November 2008): 45–47. http://dx.doi.org/10.4028/www.scientific.net/msf.607.45.
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Positron lifetime spectra were measured for several alkanes under high pressure of argon and nitrogen. In the case of argon intercalation, the dependence of melting temperature on pressure is nonmonotonous, while in nitrogen this effect does not appear.
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Moritomo, Yutaka, Masamitsu Takachi, Yutaro Kurihara, and Tomoyuki Matsuda. "Synchrotron-Radiation X-Ray Investigation of Li+/Na+Intercalation into Prussian Blue Analogues." Advances in Materials Science and Engineering 2013 (2013): 1–17. http://dx.doi.org/10.1155/2013/967285.
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Prussian blue analogies (PBAs) are promising cathode materials for lithium ion (LIB) and sodium ion (SIB) secondary batteries, reflecting their covalent and nanoporous host structure. With use of synchrotron-radiation (SR) X-ray source, we investigated the structural and electronic responses of the host framework of PBAs against Li+and Na+intercalation by means of the X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS). The structural investigation reveals a robust nature of the host framework against Li+and Na+intercalation, which is advantageous for the stability and lifetime of the batteries. The spectroscopic investigation identifies the redox processes in respective plateaus in the discharge curves. We further compare these characteristics with those of the conventional cathode materials, such as, LiCoO2, LiFePO4, and LiMn2O4.
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Shu, Guiqing, Jing Zhao, Xiu Zheng, Mengdie Xu, Qi Liu, and Minfeng Zeng. "Modification of Montmorillonite with Polyethylene Oxide and Its Use as Support for Pd0 Nanoparticle Catalysts." Polymers 11, no. 5 (April 29, 2019): 755. http://dx.doi.org/10.3390/polym11050755.
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In this study, montmorillonite (MMT) was modified by intercalating polyethylene oxide (PEO) macromolecules between the interlayer spaces in an MMT-water suspension system. X-ray diffraction results revealed that the galleries of MMT were expanded significantly after intercalation of different loading of PEO. MMT/PEO 80/20 composite was chosen as the support platform for immobilization of Pd species in preparing novel heterogeneous catalysts. After immobilization of Pd species, the interlayer spacing of MMT/PEO (80/20) (1.52 nm) was further increased to 1.72 nm (Pd2+@MMT/PEO) and 1.73 nm (Pd0@MMT/PEO), confirming the well-immobilization of the Pd species in the interlayer spaces of PEO-modified MMT. High-resolution transmission electron microscopy (HR-TEM) observation results confirmed that Pd nanoparticles were confined inside the interlayer space of MMT and/or dispersed well on the outer surface of MMT. The conversion of Pd2+ to Pd0 species was evidenced by binding energy characterization with X-ray photo electron spectroscopy (XPS). The microstructure variation caused by the Pd immobilization was sensitively detected by positron annihilation lifetime spectroscopy (PALS) studies. The prepared Pd0@MMT/PEO (0.2/80/20) catalytic composite exhibits good thermal stability up to around 200 °C, and it showed high activities for Heck reactions between aryl iodides and butyl acrylates and could be recycled for five times. The correlations between the microstructure and properties of the Pd@MMT/PEO catalytic composites were discussed.
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Zhou, Bin, Ke Liu, Xin Liu, Ka Yi Yung, Carrie M. Bartsch, Emily M. Heckman, Frank V. Bright, Mark T. Swihart, and Alexander N. Cartwright. "Enhanced Performance from a Hybrid Quenchometric Deoxyribonucleic Acid (DNA) Silica Xerogel Gaseous Oxygen Sensing Platform." Applied Spectroscopy 68, no. 11 (November 2014): 1302–5. http://dx.doi.org/10.1366/13-07430.
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A complex of salmon milt deoxyribonucleic acid (DNA) and the cationic surfactant cetyltrimethylammonium (CTMA) forms an organic-soluble biomaterial that can be readily incorporated within an organically modified silane-based xerogel. The photoluminescence (PL) intensity and excited-state luminescence lifetime of tris(4,7′-diphenyl-1, 10′-phenanathroline) ruthenium(II) [(Ru(dpp)3]2+, a common O2 responsive luminophore, increases in the presence of DNA-CTMA within the xerogel. The increase in the [Ru(dpp)3]2+ excited-state lifetime in the presence of DNA-CTMA arises from DNA intercalation that attenuates one or more non-radiative processes, leading to an increase in the [Ru(dpp)3]2+ excited-state lifetime. Prospects for the use of these materials in an oxygen sensor are demonstrated.
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Kunc, Jan, and Martin Rejhon. "Raman 2D Peak Line Shape in Epigraphene on SiC." Applied Sciences 10, no. 7 (March 30, 2020): 2354. http://dx.doi.org/10.3390/app10072354.
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We measured a 2D peak line shape of epitaxial graphene grown on SiC in high vacuum, argon and graphene prepared by hydrogen intercalation from the so called buffer layer on a silicon face of SiC. We fitted the 2D peaks by Lorentzian and Voigt line shapes. The detailed analysis revealed that the Voigt line shape describes the 2D peak line shape better. We have determined the contribution of the homogeneous and inhomogeneous broadening. The homogeneous broadening is attributed to the intrinsic lifetime. Although the inhomogeneous broadening can be attributed to the spatial variations of the charge density, strain and overgrown graphene ribbons on the sub-micrometer length scales, we found dominant contribution of the strain fluctuations. The quasi free-standing graphene grown by hydrogen intercalation is shown to have the narrowest linewidth due to both homogeneous and inhomogeneous broadening.
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Chinnathambi, Shanmugavel, Subramani Karthikeyan, Devadasan Velmurugan, Nobutaka Hanagata, Prakasarao Aruna, and Singaravelu Ganesan. "Investigations on the Interactions of 5-Fluorouracil with Herring Sperm DNA: Steady State/Time Resolved and Molecular Modeling Studies." Biophysical Reviews and Letters 10, no. 02 (June 2015): 115–33. http://dx.doi.org/10.1142/s1793048015500034.
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In the present study, the interaction of 5-Fluorouracil with herring sperm DNA is reported using spectroscopic and molecular modeling techniques. This binding study of 5-FU with hs-DNA is of paramount importance in understanding chemico–biological interactions for drug design, pharmacy and biochemistry without altering the original structure. The challenge of the study was to find the exact binding mode of the drug 5-Fluorouracil with hs-DNA. From the absorption studies, a hyperchromic effect was observed for the herring sperm DNA in the presence of 5-Fluorouracil and a binding constant of 6.153 × 103 M-1 for 5-Fluorouracil reveals the existence of weak interaction between the 5-Fluorouracil and herring sperm DNA. Ethidium bromide loaded herring sperm DNA showed a quenching in the fluorescence intensity after the addition of 5-Fluorouracil. The binding constants for 5-Fluorouracil stranded DNA and competitive bindings of 5-FU interacting with DNA–EB systems were examined by fluorescence spectra. The Stern–Volmer plots and fluorescence lifetime results confirm the static quenching nature of the drug-DNA complex. The binding constant Kb was 2.5 × 104 L mol-1 and the number of binding sites are 1.17. The 5-FU on DNA system was calculated using double logarithmic plot. From the Forster nonradiative energy transfer study it has been found that the distance of 5-FU from DNA was 4.24 nm. In addition to the spectroscopic results, the molecular modeling studies also revealed the major groove binding as well as the partial intercalation mode of binding between the 5-Fluorouracil and herring sperm DNA. The binding energy and major groove binding as -6.04 kcal mol-1 and -6.31 kcal mol-1 were calculated from the modeling studies. All the testimonies manifested that binding modes between 5-Fluorouracil and DNA were evidenced to be groove binding and in partial intercalative mode.
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Grant, Alex, and Colm O'Dwyer. "Operando Raman Spectroscopy of Phase Changes in Nanocrystalline Metal Oxide Lithium-Ion Battery Electrodes." ECS Meeting Abstracts MA2022-02, no. 1 (October 9, 2022): 94. http://dx.doi.org/10.1149/ma2022-02194mtgabs.
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As the demands for clean electricity, transport and highly functional portable electronics grow faster than ever, energy storage remains the main roadblock to progression. Electrochemical devices such as lithium-ion batteries (LIBs), have been the source of most success in overcoming this roadblock. The primary issue with these devices is lifetime decay due primarily to the degradation of the electrodes within the battery. Nanocrystalline materials are often chosen,1 which enhance battery performance by reducing ion diffusion lengths and thus improving rate capabilities. However, structural changes prove difficult to monitor due to their dimensions. The electrochemical processes which cause these changes are also difficult to probe because of their metastability and lifetimes, which can be of nanosecond to sub nanosecond time domains.2 Consequently, the development of methods to capture these processes proves challenging, requiring state-of-the-art techniques. Our work demonstrates that the processes which lead to electrode degradation can in fact be captured by using novel cell designs that provide the ability to adapt analytical techniques to probe battery systems in real time. Raman spectroscopy is particularly useful for multi-layered materials such as the porous metal oxides often used in battery electrodes.3 Information can be revealed on crystal structure, electronic structure, lattice vibrations and flake thickness of layered materials, and can be used to probe the strain, stability, charge transfer, stoichiometry, and stacking order.4 The correlation between the capacity of intercalation in an electrode to the degree of disorder in the material can also be determined.5 Such analysis can be performed during cycling, once the cell is modified to enable light penetration. A pathway is usually provided in the form of an optical window, allowing measurements to be obtained non-destructively in real-time.6 The window material must be transparent to the frequency of incident light chosen for measurements.7 These constitute spectroelectrochemical cells, providing the ability to perform electrochemical and optical measurements simultaneously. Here, we demonstrate a non-destructive approach to monitoring battery degradation in operando. Access for Raman spectroscopy during cycling is provided by a novel cell design. Sapphire is employed as window material, transparent to the 532 nm laser beam used for our Raman measurements. We describe the process applied to a lithium-ion battery based on a metal oxide inverse opals8,9 where the interconnected order porous structure is known to facilitate stable and long term cycling in the absence of binders and conductive additives11-17. However, the same methodology can be extended to any electrode materials with Raman active phase changes at the electrode-electrolyte interface.10 This work provides information on structural and phase changes to the electrode which are compared to microscopy and electrochemical data. References 1 C. Zhu, R. E. Usiskin, Y. Yu, and J. Maier, Science 358, eaao2808 (2017). 2 O. Pecher, J. Carretero-González, K. J. Griffith, and C. P. Grey, Chemistry of Materials 29, 213 (2017). 3 S. Fang, D. Bresser, and S. Passerini, Advanced Energy Materials 10, 1902485 (2020). 4 J.-B. Wu, M.-L. Lin, X. Cong, H.-N. Liu, and P.-H. Tan, Chemical Society Reviews 47, 1822 (2018). 5 K. Kirshenbaum, D. Bock, C.-Y. Lee, Z. Zhong, K. Takeuchi, A. Marschilok, and E. Takeuchi, Science 347, 149 (2015). 6 E. Armstrong, D. McNulty, H. Geaney, and C. O’Dwyer, ACS Applied Materials & Interfaces 7, 27006 (2015). 7 L. Mai, Y. Dong, L. Xu, and C. Han, Nano Letters 10, 4273 (2010). 8 A. Lonergan, D. McNulty, and C. O'Dwyer, Journal of Applied Physics 124, 095106 (2018). 9 J. Yu, J. Lei, L. Wang, J. Zhang, and Y. Liu, Journal of Alloys and Compounds 769, 740 (2018). 10 C. Julien and A. Mauger, AIMS Materials Science 5, 650 (2018). 11 S. O'Hanon, D. McNulty, R. Tian, J. Coleman, and C. O'Dwyer, J. Electrochem. Soc. 167, 140532 (2020). 12 D. McNulty, H. Geaney, Q. Ramasse, and C. O'Dwyer, 2005073 (2020). 13 D. McNulty, H. Geaney, D. Buckley, and C. O'Dwyer, Nano Energy 43, 11 (2018). 14 D. McNulty, E. Carroll, and C. O'Dwyer, Adv. Energy Mater. 7, 1602291 (2017). 15 D. McNulty, A. Lonergan, S. O'Hanlon, and C. O'Dwyer, Solid State Ionics 314, 195 (2018). 16 S. O'Hanlon, D. McNulty, and C. O'Dwyer, J. Electrochem. Soc. 164, D111 (2017). 17 C. O'Dwyer, Adv. Mater. 28, 5681 (2016).
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Saliba, Daniel, and Mazen Al-Ghoul. "Kinetics of intercalation of fluorescent probes in magnesium–aluminium layered double hydroxide within a multiscale reaction–diffusion framework." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 374, no. 2080 (November 13, 2016): 20160138. http://dx.doi.org/10.1098/rsta.2016.0138.
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We report the synthesis of magnesium–aluminium layered double hydroxide (LDH) using a reaction–diffusion framework (RDF) that exploits the multiscale coupling of molecular diffusion with chemical reactions, nucleation and growth of crystals. In an RDF, the hydroxide anions are allowed to diffuse into an organic gel matrix containing the salt mixture needed for the precipitation of the LDH. The chemical structure and composition of the synthesized magnesium–aluminium LDHs are determined using powder X-ray diffraction (PXRD), thermo-gravimetric analysis, differential scanning calorimetry, solid-state nuclear magnetic resonance (SSNMR), Fourier transform infrared and energy dispersive X-ray spectroscopy. This novel technique also allows the investigation of the mechanism of intercalation of some fluorescent probes, such as the neutral three-dimensional rhodamine B (RhB) and the negatively charged two-dimensional 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS), using in situ steady-state fluorescence spectroscopy. The incorporation of these organic dyes inside the interlayer region of the LDH is confirmed via fluorescence microscopy, solid-state lifetime, SSNMR and PXRD. The activation energies of intercalation of the corresponding molecules (RhB and HPTS) are computed and exhibit dependence on the geometry of the involved probe (two or three dimensions), the charge of the fluorescent molecule (anionic, cationic or neutral) and the cationic ratio of the corresponding LDH. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’.
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Neale, Alex R., David Costa Milan, Filipe Braga, Igor Sazanovich, and Laurence J. Hardwick. "Operando electrochemical Kerr Gated Raman Spectroscopy to Probe the High States of Charge in Graphite Electrodes for Li-Ion Batteries." ECS Meeting Abstracts MA2022-01, no. 6 (July 7, 2022): 2475. http://dx.doi.org/10.1149/ma2022-0162475mtgabs.
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In order to improve the lifetime of lithium ion (Li-ion) cells, methods to reliably probe the cell state of charge are essential to track lithium inventory loss and understand the relation to key degradation processes in the cell. NMR and X-ray/neutron scattering techniques have been demonstrated to probe the full range of intercalation from pure graphite through to stage 1 LiC6.1-3 While Raman spectroscopy/microscopy has been proven a powerful tool for the probing the earlier stages 4 and 3 of Li intercalation into graphite electrodes, the process is plagued by significant growth in competing fluorescence/emission signals as the intercalation proceeds through the lower stages between Li0.5C6 and LiC6. Coupled with a loss of Raman scattering intensity due to increased conductivities of the lithiated graphite,4, 5 the graphite bands also become swamped by the growth of overlapping fluorescence/emission signals, becoming difficult to reliably observe/assign. Consequently, diagnosing the state of charge of the highly lithiated graphite electrode by Raman spectroscopy is challenging. To overcome this, we report in this work the use of operando electrochemical Kerr gated Raman spectroscopy to track the critical changes in the graphitic bands during the Li intercalation process into a graphite negative electrode. Kerr gated Raman spectroscopy is a fluorescence suppression technique that exploits the varied time domains of the Raman scattering and fluorescence/emission processes. We have previously reported on the use of Kerr gated Raman spectroscopy as an effective tool to measure the Raman spectra of highly fluorescing, degraded/aged battery electrolyte materials based on the lithium hexafluorophosphate salt.6 In this work, a dedicated operando measurement cell was designed to permit observation of the graphite working electrode in the Li|graphite half-cell during electrochemical Li intercalation. Therein, the Kerr gated Raman spectra are compared with conventional continuous wave Raman spectroscopy, outlining the benefits and limitations of both methodologies. Importantly, owing to the efficacy of the Kerr gate in filtering out a significant portion of the problematic emission signals, the graphitic Raman bands could be observed even during the transitions through intercalation stages 2 and 1 (i.e., through Li0.5C6 to LiC6) with much greater clarity than has been achieved by conventional Raman techniques. K. Märker, C. Xu and C. P. Grey, J. Am. Chem. Soc., 142, 17447 (2020). S. Taminato, M. Yonemura, S. Shiotani, T. Kamiyama, S. Torii, M. Nagao, Y. Ishikawa, K. Mori, T. Fukunaga, Y. Onodera, T. Naka, M. Morishima, Y. Ukyo, D. S. Adipranoto, H. Arai, Y. Uchimoto, Z. Ogumi, K. Suzuki, M. Hirayama and R. Kanno, Sci. Rep., 6, 28843 (2016). A. H. Whitehead, K. Edström, N. Rao and J. R. Owen, J. Power Sources, 63, 41 (1996). M. Inaba, H. Yoshida, Z. Ogumi, T. Abe, Y. Mizutani and M. Asano, J. Electrochem. Soc., 142, 20 (1995). L. J. Hardwick, H. Buqa and P. Novák, Solid State Ionics, 177, 2801 (2006). L. Cabo-Fernandez, A. R. Neale, F. Braga, I. V. Sazanovich, R. Kostecki and L. J. Hardwick, Phys. Chem. Chem. Phys., 21, 23833 (2019).
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Biswas, Jyoti, Mengjia Gaowei, Ao Liu, Shashi Poddar, Liliana Stan, John Smedley, Jerzy T. Sadowski, and Xiao Tong. "Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode." APL Materials 10, no. 11 (November 1, 2022): 111115. http://dx.doi.org/10.1063/5.0122937.
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Alkali antimonide photocathodes have wide applications in free-electron lasers and electron cooling. The short lifetime of alkali antimonide photocathodes necessitates frequent replacement of the photocathodes during a beam operation. Furthermore, exposure to mediocre vacuum causes loss of photocathode quantum efficiency due to the chemical reaction with residual gas molecules. Theoretical analyses have shown that covering an alkali antimonide photocathode with a monolayer graphene or hexagonal boron nitride protects it in a coarse vacuum environment due to the inhibition of chemical reactions with residual gas molecules. Alkali antimonide photocathodes require an ultra-high vacuum environment, and depositing a monolayer 2D material on it poses a serious challenge. In the present work, we have incorporated a novel method known as intercalation, in which alkali atoms pass through the defects of a graphene thin film to create a photocathode material underneath. Initially, Sb was deposited on a Si substrate, and a monolayer graphene was transferred on top of the Sb film. Heat cleaning around 550–600 °C effectively removed the Sb oxides, leaving metallic Sb underneath the graphene layer. Depositing Cs on top of a monolayer graphene enabled the intercalation process. Atomic force microscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, low energy electron microscopy, and x-ray diffraction measurements were performed to evaluate photocathode formation underneath the monolayer graphene. Our analysis shows that Cs penetrated the graphene and reacted with Sb and formed Cs3Sb.
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Besli, Munir, Saravanan Kuppan, Louis Hartmann, Jay Deshmukh, Libin Zhang, and Michael Metzger. "(Invited) Electrochemical Stability of Prussian Blue Analogs and Implications for Energy Storage and Water Desalination Applications." ECS Meeting Abstracts MA2022-02, no. 27 (October 9, 2022): 1064. http://dx.doi.org/10.1149/ma2022-02271064mtgabs.
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The increasing share of renewables in our electricity grid requires affordable and scalable battery technology that uses sustainable materials and has long lifetime. At the same time, growing water scarcity necessitates new desalination technologies with a similar requirement for sustainability and lifetime. Prussian blue analogs (PBAs), e.g., manganese hexacyanoferrate, MnFe(CN)6, or nickel hexacyanoferrate, NiFe(CN)6, are promising intercalation materials for secondary batteries.1–4 Recently, this material class has been shown to be suitable for a novel energy-efficient water desalination approach, based on sodium intercalation into PBAs, sometimes referred to as battery desalination.5–8 Hence, PBAs are potentially suitable electrode materials for, both, energy storage and water desalination, but it is important to investigate the materials’ stability to processing conditions and repeated ion intercalation. Prussian blue analogs like NaxMnFe(CN)6, 0<x<2, show high sensitivity towards moisture, which results in structural change and loss of sodium from the structure.9,10 Different approaches can be utilized to mitigate this issue, such as surface coating or handling of the material under strictly inert conditions, starting from the storage of powder to slurry preparation and electrode processing.9,11 In this study, we investigated the changes in surface chemistry during ambient storage, water exposure and subsequent heating of stored PBAs. Infrared spectroscopy (ATR-FTIR) and thermal analysis (TGA-MS) of materials stored for different times ranging from one hour to one week show a sharp increase in the moisture content of the active material. X-ray diffraction of exposed materials shows a clear trend between hydration state and crystal structure. Furthermore, surface hydroxides and carbonates are found by ATR-FTIR. A reheating step at relatively low temperature shows the release of adsorbed and interstitial water, but hydroxides and carbonates remain on the surface of the active material. The moisture stability of PBAs has important implications for aqueous electrode processing in energy storage applications and water-based device operation in desalination applications. We demonstrate effective drying strategies of electrodes made with aqueous slurries and appropriate binders. The as-prepared water-based electrodes show similar cycling stability as their non-aqueous counterparts. In the desalination context, exposure of the active material to water is unavoidable and may reduce performance and lifetime since the material remains hydrated during operation. We quantify performance and lifetime metrics of the novel battery desalination cells that employ NiFe(CN)6 electrodes at opposite state-of-charge separated by an anion exchange membrane.12 Using objective metrics like retention of specific capacity (mAh/g), energy consumption (Wh/l) and productivity (l/h/m2) we show that these cells achieve vastly different performance for removal of monovalent and divalent ions. Stable charge/discharge cycling can be achieved for over 500 cycles with NaCl feed water, but rapid aging is observed with CaCl2 feeds. Synchrotron-based characterization of NiFe(CN)6 electrodes from the battery desalination cells is used to elucidate the reason for capacity fade (see Figure 1). X-ray absorption spectroscopy and X-ray fluorescence spectroscopy reveal Fe dissolution from the NiFe(CN)6 active material as a primary aging mode with CaCl2 water feeds. Based on the performance of Prussian blue analogs in, both, energy storage and water desalination, we will discuss potential synergies between these fields and strategies for efficient device design.13 References C. D. Wessells, S. V. Peddada, R. A. Huggins, and Y. Cui, Nano Lett., 11, 5421–5425 (2011). C. D. Wessells et al., ACS Nano, 6, 1688–1694 (2012). M. Pasta et al., Nat. Commun., 5, 1–9 (2014). A. Firouzi et al., Nat. Commun., 9 (2018). M. Pasta, C. D. Wessells, Y. Cui, and F. La Mantia, Nano Lett., 12, 839–843 (2012). J. Lee, S. Kim, and J. Yoon, ACS Omega, 2, 1653–1659 (2017). T. Kim, C. A. Gorski, and B. E. Logan, Environ. Sci. Technol. Lett., 4, 444–449 (2017). S. Porada, A. Shrivastava, P. Bukowska, P. M. Biesheuvel, and K. C. Smith, Electrochim. Acta, 255, 369–378 (2017). D. O. Ojwang et al., ACS Appl. Mater. Interfaces, 13, 10054–10063 (2021). J. Song et al., J. Am. Chem. Soc., 137, 2658–2664 (2015). L. Yang et al., J. Power Sources, 448, 227421 (2020). M. M. Besli et al., Desalination, 517, 115218 (2021). M. Metzger et al., Energy Environ. Sci., 13, 1544–1560 (2020). Figure 1. (a) Three-electrode cells for evaluation of electrochemical stability of NiFe(CN)6 towards mono- and divalent ion intercalation. (b) Specific capacity versus cycle number for 1C cycling with high and low concentrations of NaCl or CaCl2. (c) Visual inspection of electrolyte, revealing strong discoloration and brown precipitate after 300 cycles with 1 M CaCl2, and no discoloration after 400 cycles with 1 M NaCl. Figure 1
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Besli, Muenir M., Saravanan Kuppan, Sharon E. Bone, Sami Sainio, Sondra Hellstrom, Jake Christensen, and Michael Metzger. "Performance and lifetime of intercalative water deionization cells for mono- and divalent ion removal." Desalination 517 (December 2021): 115218. http://dx.doi.org/10.1016/j.desal.2021.115218.
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Andersson, Johanna, Louise H. Fornander, Maria Abrahamsson, Eimer Tuite, Pär Nordell, and Per Lincoln. "Lifetime Heterogeneity of DNA-Bound dppz Complexes Originates from Distinct Intercalation Geometries Determined by Complex–Complex Interactions." Inorganic Chemistry 52, no. 2 (December 26, 2012): 1151–59. http://dx.doi.org/10.1021/ic302626d.
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Ibrahim, G. M., S. Melhi Alshahrani, B. El-Gammal, Eid H. Alosaimi, Habib Elhouichet, Hamdan A. S. Al-Shamiri, A. Z. Al-Mokadem, and Nasser S. Awwad. "Quantized molecular intercalations of Rhodamine 6G laser dye onto polymethylmethacrylate host exciplex." Materials Express 12, no. 2 (February 1, 2022): 288–304. http://dx.doi.org/10.1166/mex.2022.2157.
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Polymethylmethacrylate (PMMA) and Rhodamine 6G (R6G), were used to achieve an electronically excited R6G/PMMA complex of definite stoichiometry as an active laser exciplex, pumped by different laser sources. This paper is the first that is capable of interpretation of the interactions of the reactants to form the exciplex on the molecular level using DFT. The system was prepared by thermochemical polymerization, and structurally identified using FTIR, XRD and SEM in conjunction with DSC. In low-to moderate-loading of R6G, FTIR and XRD studies indicated a good interaction between PMMA and R6G to give poor-or semi-crystalline structures. Higher dye loadings were achieved for the synthesized exciplex; loading of PMMA with 0.25 Wt-% R6G decreased the glass transition temperature from 98.74 °C to 70.08 °C. However, increasing the loading with R6G to 5 Wt-% and 20 Wt-% increased the Tg values to 86.26 and 91.90 °C, respectively. MD simulations were conducted; the electronic mobility within the system was related to different quantum parameters, EHOMO, ELUMO, η, μ and ω were about -7.671 eV, -5.241 eV, 1.215 eV, -6.456 eV and 17.1522 eV, respectively. DFT calculations indicated that R6G/PMMA has a characteristic lasing stability, so that the lasing lifetimes about 8000 pulses and efficiencies about 21% were obtained.
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Wang, Hansen, Yangying Zhu, Sang Cheol Kim, Allen Pei, Yanbin Li, David T. Boyle, Hongxia Wang, et al. "Underpotential lithium plating on graphite anodes caused by temperature heterogeneity." Proceedings of the National Academy of Sciences 117, no. 47 (November 9, 2020): 29453–61. http://dx.doi.org/10.1073/pnas.2009221117.
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Rechargeability and operational safety of commercial lithium (Li)-ion batteries demand further improvement. Plating of metallic Li on graphite anodes is a critical reason for Li-ion battery capacity decay and short circuit. It is generally believed that Li plating is caused by the slow kinetics of graphite intercalation, but in this paper, we demonstrate that thermodynamics also serves a crucial role. We show that a nonuniform temperature distribution within the battery can make local plating of Li above 0 V vs. Li0/Li+(room temperature) thermodynamically favorable. This phenomenon is caused by temperature-dependent shifts of the equilibrium potential of Li0/Li+. Supported by simulation results, we confirm the likelihood of this failure mechanism during commercial Li-ion battery operation, including both slow and fast charging conditions. This work furthers the understanding of nonuniform Li plating and will inspire future studies to prolong the cycling lifetime of Li-ion batteries.
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Li, Zhi, Keren Jiang, Faheem Khan, Ankur Goswami, Jun Liu, Ali Passian, and Thomas Thundat. "Anomalous interfacial stress generation during sodium intercalation/extraction in MoS2 thin-film anodes." Science Advances 5, no. 1 (January 2019): eaav2820. http://dx.doi.org/10.1126/sciadv.aav2820.
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Although the generation of mechanical stress in the anode material is suggested as a possible reason for electrode degradation and fading of storage capacity in batteries, only limited knowledge of the electrode stress and its evolution is available at present. Here, we show real-time monitoring of the interfacial stress of a few-layer MoS2 system under the sodiation/desodiation process using microcantilever electrodes. During the first sodiation with a voltage plateau of 1.0 to 0.85 V, the MoS2 exhibits a compressive stress (2.1 Nm−1), which is substantially smaller than that measured (9.8 Nm−1) during subsequent plateaus at 0.85 to 0.4 V due to the differential volume expansion of the MoS2 film. The conversion reaction to Mo below 0.1 V generates an anomalous compressive stress of 43 Nm−1 with detrimental effects. These results also suggest the existence of a separate discharge stage between 0.6 and 0.1 V, where the generated stress is only approximately one-third of that observed below 0.1 V. This approach can be adapted to help resolve the localized stress in a wide range of electrode materials, to gain additional insights into mechanical effects of charge storage, and for long-lifetime battery design.
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MOLENDA, J. "MATERIAL PROBLEMS AND PROSPECTS OF Li-ION BATTERIES FOR VEHICLES APPLICATIONS." Functional Materials Letters 04, no. 02 (June 2011): 107–12. http://dx.doi.org/10.1142/s1793604711001816.
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This paper reviews material issues of development of Li -ion batteries for vehicles application. The most important of them is safety, which is related to application of nonflammable electrolyte with large electrochemical window and possibility of forming protective SEI (solid/electrolyte interface) to prevent plating of lithium on carbon anode during fast charge of the batteries. The amount of electrical energy, which a battery is able to deliver, depend on the electromotive power of the cell as well as on its capacity — both these factors are related to the chemistry of electrode materials. Nanotechnology applied to electrode materials may be a breakthrough for Li -batteries performance due to extreme reactivity of nanoparticles in relation to lithium. The electrode-electrolyte interface phenomena are decisive for a cell lifetime. Review of physicochemical properties of intercalated transition metal compounds with layered, spinel or olivine-type structure is provided in order to correlate their microscopic electronic properties, i.e. the nature of electronic states, with the efficiency of lithium intercalation process, which is controlled by the chemical diffusion coefficient of lithium. Data concerning cell voltage and character of discharge curves for various materials are correlated with the nature of chemical bonding and electronic structure. Proposed electronic model of the intercalation process allow for prediction and design of operational properties of intercalated electrode materials. Proposed method of measuring the Li x M a X b potential on the basis of the measurement of the electromotive force of the Li / Li +/ Li x M a X b electrochemical cell is a powerful tool of solid state physics allowing for direct observation of the Fermi level changes in such systems as a function of lithium content.
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Chen, Nai-Tzu, Chia-Yan Wu, Chao-Yu Chung, Yeukuang Hwu, Shih-Hsun Cheng, Chung-Yuan Mou, and Leu-Wei Lo. "Probing the Dynamics of Doxorubicin-DNA Intercalation during the Initial Activation of Apoptosis by Fluorescence Lifetime Imaging Microscopy (FLIM)." PLoS ONE 7, no. 9 (September 18, 2012): e44947. http://dx.doi.org/10.1371/journal.pone.0044947.
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Pietrzyk, S., P. Palimaka, and W. Gębarowski. "The Effect of Liquid Aluminium on the Corrosion of Carbonaceous Materials." Archives of Metallurgy and Materials 59, no. 2 (June 1, 2014): 545–50. http://dx.doi.org/10.2478/amm-2014-0090.
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Abstract During different aluminum smelting processes occur direct contact of liquid metal and carbon materials, which are the main constituent for the lining of the cells, furnaces, crucibles and ladles, etc. As a result, processes of aluminium carbide formation at the interfacial area and its subsequent dissolution occurs. Those are recognized as one of the most important mechanisms causing surface wear and decrease lifetime of the equipment, especially in aluminium electrolysis. Present work is aimed at deeper study of the initial steps of Al4C3 formation at the aluminium/ carbon interface. Three types of carbonaceous materials: amorphous, semigraphitic and graphitized, in the presence and absence of cryolite melts, were examined. As it is very difficult to study layer of Al4C3 in situ, two indirect experimental techniques were used to investigate aluminium carbide formation: measurements of the potential and the electrical resistance. It was concluded that the process of early formation of aluminium carbide depends on many processes associated with the presence of electrolyte (intercalation, penetration and dissolution) as well as the structure of carbon materials - especially the presence of the disordered phase.
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Sailer, B. L., A. J. Nastasi, J. G. Valdez, J. A. Steinkamp, and H. A. Crissman. "Interactions of intercalating fluorochromes with DNA analyzed by conventional and fluorescence lifetime flow cytometry utilizing deuterium oxide." Cytometry 25, no. 2 (October 1, 1996): 164–72. http://dx.doi.org/10.1002/(sici)1097-0320(19961001)25:2<164::aid-cyto5>3.0.co;2-h.
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McIntosh, Sara L., Todor G. Deligeorgiev, Nikolai I. Gadjev, and Linda B. McGown. "Mono- and bis-intercalating dyes for multiplex fluorescence lifetime detection of DNA restriction fragments in capillary electrophoresis." ELECTROPHORESIS 23, no. 10 (May 2002): 1473. http://dx.doi.org/10.1002/1522-2683(200205)23:10<1473::aid-elps1473>3.0.co;2-#.
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Aguado, Fernando, Rosa Martín-Rodríguez, Carmen Pesquera, Rafael Valiente, and Ana C. Perdigón. "Adsorptive Capture of Ionic and Non-Ionic Pollutants Using a Versatile Hybrid Amphiphilic-Nanomica." Nanomaterials 11, no. 12 (November 23, 2021): 3167. http://dx.doi.org/10.3390/nano11123167.
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A versatile, functional nanomaterial for the removal of ionic and non-ionic pollutants is presented in this work. For that purpose, the high charge mica Na-4-Mica was exchanged with the cationic surfactant (C16H33NH(CH3)2)+. The intercalation of the tertiary amine in the swellable nano-clay provides the optimal hydrophilic/hydrophobic nature in the bidimensional galleries of the nanomaterial responsible for the dual functionality. The organo-mica, made by functionalization with C16H33NH3+, was also synthesized for comparison purposes. Both samples were characterized by X-ray diffraction techniques and transmission electron microscopy. Then, the samples were exposed to a saturated atmosphere of cyclohexylamine for two days, and the adsorption capacity was evaluated by thermogravimetric measurements. Eu3+ cations served as a proof of concept for the adsorption of ionic pollutants in an aqueous solution. Optical measurements were used to identify the adsorption mechanism of Eu3+ cations, since Eu3+ emissions, including the relative intensity of different f–f transitions and the luminescence lifetime, can be used as an ideal spectroscopic probe to characterize the local environment. Finally, the stability of the amphiphilic hybrid nanomaterial after the adsorption was also tested.
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Alikin, Denis, Boris Slautin, and Andrei Kholkin. "Revealing Lithiation Kinetics and Battery Degradation Pathway in LiMn2O4-Based Commercial Cathodes via Electrochemical Strain Microscopy." Batteries 8, no. 11 (November 5, 2022): 220. http://dx.doi.org/10.3390/batteries8110220.
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The capacity fade during the cycling of lithium batteries is a key factor limiting further progress in the improvement of electric vehicles, wearable electronic devices, alternative energy sources, etc. One of the main reasons for capacity loss is battery cathode degradation, which significantly influences the battery lifetime. Despite in-depth knowledge of battery degradation at the chemical level, the kinetics of the degradation at the resolution of the individual elements of the cathode are not fully understood. Here, we studied lithiation kinetics in commercial cathodes based on lithium manganese spinel using the electrochemical strain microscopy local method. Supported by the experimental finding, the “viscous fingers” model of lithium ions intercalation–deintercalation in individual particles of the cathode was proposed. The non-linear dynamics of the lithiation front were suggested to be stimulated by the non-uniform stress field and gradient of the chemical potential. Irregularity of the lithiation front causes the formation of the residual lithiated pocket in the delithiated particles, which effectively reduces the volume available for chemical reaction. The obtained results shed further light on the degradation of the lithium battery cathodes and can be applicable for other cathode materials.
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Hao, Junnan, Fuhua Yang, Shilin Zhang, Hanna He, Guanglin Xia, Yajie Liu, Christophe Didier, et al. "Designing a hybrid electrode toward high energy density with a staged Li+ and PF6− deintercalation/intercalation mechanism." Proceedings of the National Academy of Sciences 117, no. 6 (January 29, 2020): 2815–23. http://dx.doi.org/10.1073/pnas.1918442117.
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Existing lithium-ion battery technology is struggling to meet our increasing requirements for high energy density, long lifetime, and low-cost energy storage. Here, a hybrid electrode design is developed by a straightforward reengineering of commercial electrode materials, which has revolutionized the “rocking chair” mechanism by unlocking the role of anions in the electrolyte. Our proof-of-concept hybrid LiFePO4 (LFP)/graphite electrode works with a staged deintercalation/intercalation mechanism of Li+ cations and PF6− anions in a broadened voltage range, which was thoroughly studied by ex situ X-ray diffraction, ex situ Raman spectroscopy, and operando neutron powder diffraction. Introducing graphite into the hybrid electrode accelerates its conductivity, facilitating the rapid extraction/insertion of Li+ from/into the LFP phase in 2.5 to 4.0 V. This charge/discharge process, in turn, triggers the in situ formation of the cathode/electrolyte interphase (CEI) layer, reinforcing the structural integrity of the whole electrode at high voltage. Consequently, this hybrid LFP/graphite-20% electrode displays a high capacity and long-term cycling stability over 3,500 cycles at 10 C, superior to LFP and graphite cathodes. Importantly, the broadened voltage range and high capacity of the hybrid electrode enhance its energy density, which is leveraged further in a full-cell configuration.
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Li, Yaqi, Jia Guo, Peter Kjær Kristensen, Daniel-Ioan Stroe, Kjeld Pedersen, and Leonid Gurevich. "(Digital Presentation) Investigation of Solid Electrolyte Interphase Formation on Highly Oriented Pyrolytic Graphite Anodes in Lithium-Ion Batteries." ECS Meeting Abstracts MA2022-02, no. 3 (October 9, 2022): 309. http://dx.doi.org/10.1149/ma2022-023309mtgabs.
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Lithium-ion batteries (LIBs) are widely used in modern society. Since LIBs represent a substantial fraction and sometimes even majority of the device cost, extending the lifetime of LIBs and understanding their degradation mechanisms draw an increasing attention. Graphite, commonly used as the negative electrode in LIBs, suffers from two main degradation mechanisms: loss of active material and loss of lithium-ion inventory. Formation of the so-called solid electrolyte interphase (SEI) layer is known as the key factor for functioning of the anode. On the one hand, its growth covering the electrode surface slows down Li-ion intercalation. On the other hand, the SEI layer both protects the graphite particles from exfoliation upon intercalation and the electrolyte from decomposition by preventing organic molecules from entering graphite. Due to surface defects of the graphite particles used in common LIBs, it is challenging to observe the SEI layer formation. Therefore, highly oriented pyrolytic graphite (HOPG), which has a perfectly smooth surface, is commonly used in SEI formation experiments. In this work, we have applied electrochemical analysis, as well as morphology and structure characterization to investigate processes involved into the formation of SEI layer. A three-electrode electrochemical cell setup was installed in a glove box under inert argon atmosphere. HOPG was used as the working electrode and lithium metal was employed as both the reference electrode (RE) and counter electrode (CE). The electrolyte was composed of 1M lithium hexafluorophosphate (LiPF6) dissolved in 1:1 v/v mixture of ethylene carbonate (EC) and diethyl carbonate (DEC). Cyclic voltammetry (CV) was performed in voltage ranges of 2, 1.5, and 0.5 V versus Li/Li+. canning Electron Microscopy (Zeiss XB1540) and Atomic Force Microscopy (Ntegra Aura) were used to characterize the morphology and topography of the HOPG electrode after CV. X-ray Photoelectron Spectroscopy (XPS, Phoibos 150 1D-DLD, XR 50, Specs) was employed to measure the elemental composition and structure at the HOPG surface. When the cycling was performed between 3 – 2 V, small particles were observed on the surface of the HOPG, which can be assigned to the deposition of electrolyte. Homogeneous microspheres started to appear when the voltage reached below 1.5 V, which can be attributed to the formation of SEI particles. As the CV range increased, which also meant an increase in the depth of discharge (DOD), the density of microspheres on the surface increased as well. The diameter of the microspheres was found to be around 80 – 100 nm at a low lithiation level, and as the HOPG electrode became fully lithiated, the size of the particles slightly increased. This finding was supported by XPS measurements where the integral of the LixPFy and LixPFyOy peak, which is related to the main constituents of SEI layer, was found to be the largest (57.68% of the full F 1s spectra peak area) in the 3 – 0 V cycle range, while a lower peak (54.56%) was observed in the 3 – 0.5 V range (in the attached Figure). These results provide an indication of how the charging method affects the capacity fade and lifetime of the LIBs. The stage from 0.5 to 0 V on HOPG is approximately equivalent to 80-100% SOC for a full cell. As was found, in this stage, the SEI film grows thicker, thereby aggravating the aging of the cell. The lifetime of LIBs can therefore be extended if cycling at high SOC is avoided. Based on this, our future work will focus on the development of an optimized multi-step fast-charging method, which can reduce degradation and extend the lifetime of commercial lithium-ion batteries. Figure 1
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Liu, Run Yu. "Recent Progress of Anode and Cathode Materials for Lithium Ion Battery." Materials Science Forum 1027 (April 2021): 69–75. http://dx.doi.org/10.4028/www.scientific.net/msf.1027.69.
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Lithium ion battery is a kind of secondary battery that mainly relies on lithium ions moving between a positive electrode and a negative electrode. Lithium-ion batteries are considered to be the most ideal automotive power battery and has been widely applied in EV industry due to the outstanding advantages including but not limited to high energy density, high open circuit voltage and wide operating temperature range. The technical bottleneck of lithium-ion power batteries is how to further increase the energy density and optimize operating performance at low temperature. Besides, how to decrease the cost for lithium ion battery is also a big problem. The higher potential end of the power supply device is called cathode materials and the lower potential end of the power supply is called anode materials. At cathode end, Lithium ion intercalation process happens during discharging cycle and lithium ion deintercalation process happens during charging.For anode end, Lithium ion deintercalation process happens during charging cycle and lithium ion insertion process happens during discharging process. Good cathode/anode materials should include but not limited to the following characters: large specific capacity density, long cycling lifetime, good rate performance, proper electric potential and relatively stable structure during charge and discharge process.
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Uppaluri, Maitri, Suryanarayana Kolluri, and Venkat R. Subramanian. "Optimal Charging Protocols to Restrict Lithium-Ion Battery Degradation." ECS Meeting Abstracts MA2022-01, no. 2 (July 7, 2022): 429. http://dx.doi.org/10.1149/ma2022-012429mtgabs.
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Lithium-ion batteries degrade due to several mechanisms that occur during cell operation. These mechanisms can be parasitic reactions that lead to loss of lithium inventory or loss of active material. Some examples of these side reactions include the growth of the solid-electrolyte interphase (SEI) layer, transition metal dissolution and deposition, lithium plating, solvent oxidation, etc. Thermal effects and mechanical fatigue on the electrodes also lead to cell aging and capacity fade. For widespread implementation of lithium-ion batteries for electric vehicles, batteries should last approximately 10 years.1 Fast charging has also been heavily researched for accelerating this prevalent circumstance. However, charging at high currents can severely degrade the cell, affecting the cell’s lifetime. Algorithms that optimize charging can be effective to reduce cell aging. Physics-based battery models can be used to design these algorithms by restricting phenomena that occur in the cell that causes cell aging. For example, lithium plating can be prevented by restricting the overpotential of the reaction. In our previous work, we have shown optimal charging profiles where the intercalation induced stresses, lithium plating and the SEI layer growth was restricted using reformulated physics-based models using model-based control 2 - 3 In this talk, we show different optimal charging protocols for restricting different mechanisms, and analyze the interplay between them to predict optimal charging profiles. References M. T. Lawder, P. W. C. Northrop, and V. R. Subramanian, J. Electrochem. Soc., 161, A2099–A2108 (2014). B. Suthar, P. W. C. Northrop, R. D. Braatz, and V. R. Subramaniand, J. Electrochem. Soc., 161, F3144–F3155 (2014). M. Pathak, D. Sonawane, S. Santhanagopalan, R. D. Braatz, and V. R. Subramanian, ECS Trans., 75, 51–75 (2017).
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Daubinger, Philip, Simon Feiler, Lukas Gold, Sarah Hartmann, and Guinevere A. Giffin. "State-of-Charge Dependent Change of the Young’s Modulus in Lithium-Ion Batteries." ECS Meeting Abstracts MA2022-01, no. 2 (July 7, 2022): 320. http://dx.doi.org/10.1149/ma2022-012320mtgabs.
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One way to increase the sustainability of lithium-ion batteries (LIB) is to extend the cycle life, e.g., in electric vehicles. To do this, the effects within a LIB must be understood and tracked over its lifetime. In addition to electrical (e.g. IR-drop) and thermal measurements (e.g. temperature inhomogeneities), a new approach for such studies is the use of ultrasound to investigate the mechanical changes inside a LIB [1]. With this low-cost technology, it is possible to detect mechanical degradation (e.g. local thickness change due to lithium plating) or Young’s moduli changes over lifetime and possibly counteract them by the battery management system. In this work a self-built device containing a LIB between two opposing transducers is used to study the impact of state-of-charge (SOC), current rate and frequency on the ultrasound signal inside the LIB. Based on the time the ultrasound signal takes to pass through the LIB (time-of-flight (TOF)), the speed of sound and the Young’s moduli can be determined. The influence of the applied current rate and the frequency of the transducer to the TOF/ speed of sound in the LIB is relatively small. However, the SOC has an impact on the TOF/ speed of sound, where the speed of sound is around 4.5% higher in the fully charged state with ~1740 m s-1 compared to the discharged state with ~1660 m s-1 (see Figure 1 (a)). One explanation for this phenomenon is the change in the lithium staging within the graphite anode. In a charged battery, the graphite anode is filled with lithium ions, which enhances the transmission properties of ultrasound. By knowing speed of sound, the Young’s modulus of the whole battery can be estimated as ~4.2 GPa in discharged state and ~5.6 GPa in the charged state (Figure 1 (b)). This significant increase can also be explained with the lithiation stages of the graphite anode, as the graphite particles themselves exhibit a threefold increase of the Young’s modulus during lithiation [2]. Additionally, the evolution of the speed of sound and Young’s moduli is studied during aging of the LIB. References: [1] Gold, L., Bach, T., Virsik, W., Schmitt, A., Müller, J., Staab, T. E., & Sextl, G. (2017). Probing lithium-ion batteries' state-of-charge using ultrasonic transmission–Concept and laboratory testing. Journal of Power Sources, 343, 536-544. [2] Qi, Y., Guo, H., Hector Jr, L. G., & Timmons, A. (2010). Threefold increase in the Young’s modulus of graphite negative electrode during lithium intercalation. Journal of The Electrochemical Society, 157(5), A558. Figure 1
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Rist, Ulrich, Yannic Sterzl, and Wilhelm Pfleging. "3D Printing of Silicon-Based Anodes for Lithium-Ion Batteries." ECS Meeting Abstracts MA2022-01, no. 2 (July 7, 2022): 427. http://dx.doi.org/10.1149/ma2022-012427mtgabs.
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In order to meet the target for the next generation lithium-ion batteries, electrochemical performance such as energy and power density must be increased significantly at the same time. Optimized electrode architectures including 3D battery concepts and advanced materials are in development to achieve this goal. The use of silicon-graphite composite electrodes instead of graphite anodes is currently investigated. This is due to the fact that silicon can provide almost one order of magnitude higher specific energy density (3579 mAh/g) in comparison to natural graphite (330 - 372 mAh/g). However, during lithiation, i.e., lithium silicide formation, a volume expansion of about 300 % can take place, while during lithium intercalation in graphite about 10 % volume expansion can be observed. A huge volume expansion leads to a tremendous mechanical degradation of the anode resulting in a drop in capacity, and a limited battery lifetime. In the presented study, laser induced forward transfer (LIFT) is applied as printing technology to develop sophisticated graphite and graphite-silicon electrode architectures with advanced electrochemical performances. LIFT was performed using a pulsed nanosecond UV laser with a repetition rate of up to 30 kHz and a maximal power of 10 W. To enable an accurate printing process during LIFT, the properties and compositions of the active material inks as well as the laser and process parameters have to be optimized. The printing process in combination with laser structuring provides a high flexibility regarding the final electrode design. In the presented study, the formation of multi-layer electrodes with spatial variation in electrode composition is achieved. As active materials silicon nanoparticles (SNPs) and various types of graphite, i.e., natural graphite, mesocarbon microbeads (MCMB), and artificial flake-like graphite with an average particle diameter of 1 µm up to 15 µm are utilized. The geometry and thickness of each printed layer is adapted with regard to an optimized electrochemical performance and cell lifetime. A single layer thickness of 5 µm up to 20 µm was achieved, while areal capacities of multi-layer anodes reaches values of 2 to 4 mAh/cm². In addition to the applied active materials and architecture concepts, different solvent and binder systems are investigated with regard to process scalability and an improved environmental compatibility. The printed electrodes are electrochemically characterized by rate capability measurements at C-rates of up to 5C. A correlation between capacity retention and electrode architecture is achieved. The results are discussed in terms of upscaling and impact on the next generation anode material.
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Bitschnau, Brigitte, Franz Mautner, Peter Parz, Werner Puff, Robert Würschum, Bernd Fuchsbichler, and Stefan Koller. "Charge-Induced Defect Formation in LixCoO2 Battery Cathodes: XRD and PA Spectroscopy Study." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1800. http://dx.doi.org/10.1107/s205327331408200x.
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Lithium-ion batteries have developed into most advanced battery systems, e.g. laptops and mobile phones. LiCoO2 is a typical intercalation battery cathode material. However, reversible charge-discharge cycling of LiCoO2 is only possible down to 50% of the available Li-ions since further removal of Li-ions drastically reduces the capacity and cycle stability. The formation of vacancy-type defects during the charging process in LixCoO2 battery cathodes was investigated by XRD and position life-time spectroscopy and Doppler broadening of positron-electron annihilation (PA) radiation as defect specific techniques [1]. Li+-extraction, which in a battery mode corresponds to charging, was performed at 293 K under electrochemical control in a 3-electrode test-cell with a Maccor Series 4000 battery tester. The composition of the lithium-ion electrode material used was: 88wt.% LiCoO2 particles, 7 wt.% carbon black as conducting agent, 5 wt.% binder material (polyvinylidene difluoride hexafluoropropylene copolymer). Structural analysis of the electrode samples was performed by means of X-Ray diffraction using a Bruker D8 Advance diffractometer in Bragg-Brentano geometry with Cu-Kα radiation. Diffractograms were measured in the 2-Theta angle range from 150to 1300and were analysed by Rietveld refinement with the programs FULLPROF [2] and X'PertHighScorePlus (Panalytical). For positron annihilation measurements a positron source (22NaCl) was sandwiched between two identical LiCoO2 electrode samples. Positron lifetime measurements were performed with a fast-fast spectrometer with a time resolution of 221 ps. The spectra were analysed by using the program pfposfit [3]. Doppler broadening (DB) measurements were performed in a coincidence setup with two high purity Ge detectors.with energy resolution for the 511 keV annihilation γ-line in the detector system corresponds to ca. 0.88keV (FWHM). Both the Doppler broadening S parameter as well as the positron lifetime component τ1 exhibit a characteristic variation with increasing amount of Li+-extraction; the S-parameter and τ1 first increases upon decreasing x from 1 to 0.6. Further Li+-extraction causes a decrease of S and τ1 (x = 0.55), followed by a re-increase for x<0.55. Conclusions: The regime of reversible charging is dominated by vacancy-type defects on the Li+-sublattice the size of which increases with increasing Li+-extraction. Indication is found that Li+-reordering which occurs at the limit of reversible Li+-extraction (x = 0.55) causes a transition from the two-dimensional agglomerates into one-dimensional vacancy chains. Degradation upon further Li+-extraction is accompanied by the formation of vacancy complexes on the Co- and anion sublattice.
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Yao, Fei, Sichen Wei, Yu Fu, Maomao Liu, Yannick Iniatius Gata, Qinrui Liu, and Huamin Li. "Dual-Phase MoS2/Mxene/CNT Ternary Nanohybrids for Efficient Electrocatalytic Hydrogen Evolution." ECS Meeting Abstracts MA2022-02, no. 8 (October 9, 2022): 644. http://dx.doi.org/10.1149/ma2022-028644mtgabs.
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Hydrogen (H2) shows great potential in reducing greenhouse gas emissions and improving energy efficiency due to its environmentally friendly nature and high gravimetric energy density [1]. It can be generated via electrochemical water splitting based on the hydrogen evolution reaction (HER). It is well known that Pt-group metals (PGMs) are excellent catalysts for HER, but their broad adoption is limited by high cost and scarcity. Recently, two-dimensional (2D) molybdenum disulfide (MoS2) is regarded as a promising alternative to PGMs due to its large surface area, rich active sites, and ideal hydrogen adsorption energy [2]. However, its practical application is hindered by the intrinsically low electrical conductivity arising from the semiconducting nature of2H phase MoS2[3]. On the other hand, 2D Ti3C2 MXene with high electrical conductivity, excellent hydrophilicity, and large interlayer distance has been intensively investigated in energy storage devices lately[4]. Compared with charge-neutral graphene, MXene exhibits a negatively charged surface due to the existence of numerous surface functional groups (-OH, -O, -F, etc.), which not only enhances the dispersion of MoS2 precursors but also promotes MoS2 nucleation, making it a superior template for MoS2 synthesis. Nevertheless, undesired oxidation of MXene occurs in aqueous solutions [5], reducing the overall catalyst stability. To address the above issues, we employed a one-step solvothermal method using DI water/DMF as bisolvent and constructed metallic 1T phase-enriched MoS2/MXene composite as HER catalyst. The advantages of using bisolvent lie in twofold: (i) suppress undesired oxidation and thus preserve high conductivity of MXene framework, and (ii) improve MoS2 electrical conductivity by inducing 2H to 1T phase transition. The introduction of metallic 1T phase MoS2 is triggered by ion intercalation. Specifically, during the synthesis, both ammonium molybdate (Mo precursor) and DMF can act as abundant sources of NH4+ which can intercalate into MoS2 layers. This process stimulated charge imbalance between Mo3+ and Mo4+ and led to the S plane sliding [6]. As a result, crystal structure distortion and therefore phase transformation of MoS2 occur along with interlayer distance expansion. To further improve the catalyst conductivity, carbon nanotubes (CNTs)were introduced into the binary composite as crosslinks to bridge the 2D islands. As a result, a low overpotential (169 mV) and Tafel slope (51 mV/dec) along with the highest turnover frequency (7 s-1 at -0.23V vs. RHE) and an ultralong lifetime (72 hours) was successfully achieved. The origin of the outstanding HER performance of the ternary composite can be ascribed to: (i) the prevention of 2D layer restacking as well as the enlarged surface area due to the 2D/2D MoS2/MXene integration and ion intercalation. This will promote the contact between electrolyte and catalyst, resulting in an increased hydrogen ion adsorption; (ii)the vertical growth of MoS2 flakes on MXene template which increases the exposure of MoS2 edge planes, maximizing the total number of active sites; (iii) the synergistically enhanced conductivity because of the formation of hybrid 1D/2D conductive network via the integration of 1T-phase metallic MoS2, conductive MXene backbone with suppressed oxidation along with the CNT crosslinks, minimizing the charge transfer resistance at the electrode/electrolyte interface. This work demonstrated an effective strategy for low-dimensional material structure-property engineering with the aim of optimizing the HER performance which will shed light on the development of the next-generation PGM-free HER electrocatalysts.
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Behler, Rachael, Fadwa Badway, and Glenn G. Amatucci. "Novel Electrolyte Development for in-Situ Formed Li-Metal Batteries Using Amplified SEI and Plating Investigations." ECS Meeting Abstracts MA2022-02, no. 2 (October 9, 2022): 123. http://dx.doi.org/10.1149/ma2022-022123mtgabs.
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The ubiquitous use of Li-ion batteries is hindered in part by limitations to achievable specific and volumetric energy. In addition to the physical constraints these properties address, they lead to higher cost per Wh. Replacing the intercalation or alloying based negative electrode leads to significant increases in both of the aforementioned energy related properties. In-situ formed or “anodeless” Li metal batteries, where Li is plated directly on the current collector, enable significant cost savings and improvement of energy of Li metal batteries relative to traditional Li metal which contain Li metal upon initial fabrication [1]. Using anodeless configurations, we imparted on an effort to investigate the deleterious capacity consuming phenomena of the plating process by electrochemically isolating the key degradation and performance limiting phenomena. Using ultra low-capacity Li metal plating (0.08mAh/cm2) in Li-metal anodeless half cells, the formation and quality of the solid electrolyte interphase (SEI) can be investigated with amplification. The solid electrolyte interphase (SEI) is a protective and passivating layer formed during the initial reduction of electrolyte. A robust SEI protects against excess electrolyte consumption and allows for subsequent stable, high efficiency cycling while being electronically resistive and ionically conductive [2]. The composition and mechanical stability of this dynamic layer influences efficiency and cycle lifetime [2]. At higher lithium plating capacities however, the influence of the SEI is not easily observed. Instead, capacity fade attributed to dendrite formation and mechanical damage to the SEI can be more easily investigated. Using higher capacity lithium plating (2.5mAh/cm2) in anodeless cell configurations, dendrite formation and capacity fade over cycle lifetime can be observed. Dendrite formation, as the result of irregular lithium deposition, can hinder the amount of active lithium available as well as lead to battery failure through short circuiting and thermal runaway [3]. In this work we have isolated the study SEI and dendrite formation electrochemically, using Li-metal and LiCoO2 counter electrode anodeless cell configurations, respectively. As a result, we developed novel non-aqueous, non-ionic liquid electrolytes that have achieved efficiency of 85% at 0.08mAh/cm2 where most of the capacity is associated with the formation of the SEI and 96% at 2.5mAh/cm2 at the more challenging initial cycles. In contrast, a standard electrolyte composition such as 1M LiPF6 EC/DMC shows poor initial efficiency of 52% at 0.08mAh/cm2 and 66% at 2.5mAh/cm2. High efficiencies were also achieved with optimized ionic liquid electrolytes. This work may provide insight into the initial stages of SEI formation and provide a systematic methodology for electrolyte optimization through SEI capacity loss and dendritic capacity fade observation. [1] S. H. Park, D. Jun, G. H. Lee, S. G. Lee, and Y. J. Lee, J. Materials Chemistry A 9 (2021) 14656-14681. [2] S. J. Park, J. Li, C. Daniel, D. Mohanty, S. Nagpure, and D. L. Wood, Carbon 105 (2016) 52-76. [3] J. B. Goodenough, J. Solid State Electrochem. 16 (2012) 2019-2029. Figure 1
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DeCaluwe, Steven C. "(Invited, Digital Presentation) Detailed Chemical Modeling of Solid Electrolyte Interphase Growth and Evolution." ECS Meeting Abstracts MA2022-01, no. 38 (July 7, 2022): 1660. http://dx.doi.org/10.1149/ma2022-01381660mtgabs.
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The solid electrolyte interphase (SEI) is a layer that forms at the anode-electrolyte interphase in lithium ion batteries. The layer forms due to voltage instability of the electrolyte at low anode potentials, but serves to passivate the electrolyte to protect against further uncontrolled decomposition. In theory, the SEI is self-limiting, but in reality, continued growth over the battery’s lifetime leads to capacity fade, poor rate capability, and eventually cell death. Though significant progress in recent years has improved the SEI’s function and stability, poor understanding of its most basic chemistry impedes “rational design” of SEI layers for advanced battery applications. Understanding and quantifying the elementary chemistry of the SEI is made challenging by the layer’s thickness (10s to ~100 nm), chemical sensitivity, mechanical fragility, and complex chemistry (upwards of 100 reactions have been proposed). For these reasons, These factors combine to make studying the fundamental chemistry of SEI growth and evolution a significant challenge. Both the computational tools to model the SEI’s complex chemistry and the experimental data required to validate such models are all too rare. This talk will provide an overview of recent efforts to model the fundamental electrochemistry of SEI growth and evolution. The simulations are based on a continuum-scale, finite-volume framework, and leverage the open-source software package Cantera to enable efficient simulation of arbitrarily complex electrochemical mechanisms. Simulation results, as in Figure 1, are validated against two operando measurements of the SEI grown on a non-intercalating tungsten anode: depth profiling via neutron reflectometry (NR), and SEI mass uptake data via quartz crystal microbalance with dissipation (QCM-D) taken during cyclic voltammetry cycling. Interrogation of the detailed model results provide insights into the complex phenomena controlling initial SEI growth, and validation against NR and QCM-D data identify prominent reaction pathways and key chemical species present in the SEI. Finally, we will conclude by discussing future steps, includuing transferring mechanistic insights to new scales, geometries, and chemistries, and coupling models with inputs from atomistic simulations. Figure 1
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Pfleging, Wilhelm, Peter Smyrek, Zheng Yijing, Ulrich Rist, Yannic Sterzl, Alexandra Meyer, and Penghui Zhu. "(Invited) 3D Electrode Architectures for High Power and High Energy Lithium-Ion Battery Operation - Recent Approaches and Process Upscaling." ECS Meeting Abstracts MA2022-02, no. 6 (October 9, 2022): 593. http://dx.doi.org/10.1149/ma2022-026593mtgabs.
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During the next decades, combustion driven cars will be completely replaced by electrical vehicles (EVs) and it seems quite obvious that liquid electrolyte lithium-ion batteries (LIBs) will be the dominating energy storage system for the next at least 5 to 10 years. As a consequence, in Europe numerous Gigafactories have recently been planned with this state of technology. However, the current lithium-ion battery technology suffers so far from some restrictions like the inability to combine high power and high energy operations at the same time. This limitation is mainly attributed to the cathode architecture and respective mass loading. In addition, the further demand for a significantly enhanced fast charging mainly requires an optimization of the anode design flanked by a high areal capacity. Advanced 3D electrode architectures based on a thick film electrode concept seem to be the most promising approach to overcome the current limitations in battery performances. However, respective technology innovations need to provide a high compatibility grade to existing manufacturing routes in order to enable the required integration in existing and planned factories. For so-called “generation 3” materials, i.e., nickel-rich lithium nickel manganese cobalt oxide (NMC) cathode and silicon-based anode materials, structuring technologies using cutting edge ultrafast high power lasers, are being developed in order to manufacture 3D electrode architectures with high areal capacity. Multibeam laser processing using diffractive optical elements and dual scanner approaches were established in order to enable high processing speeds in roll-to-roll electrode handling systems. The technology readiness level (TRL 6) is demonstrated for pouch cells geometries. For water-based NMC 622 and silicon-graphite composites the laser structuring process was developed. Different structures including hole, grid, and line patterns, were studied regarding their impact on electrochemical performances such as high-rate capability and cell lifetime. Lithium concentration profiles of unstructured and structured electrodes were studied post mortem using laser-induced breakdown spectroscopy (LIBS) in order to evaluate lithium intercalation/deintercalation efficiencies and detect possible cell degradation processes. In comparison to unstructured electrodes, 3D electrodes could hereby always be identified as superior: unstructured thick film electrodes show a significant drop in capacity retention for high power operation and tend to form hot spots acting as starting point for cell failure. The upscaling process is flanked by a further improvement of electrode design. For this purpose very recently laser induced forward transfer (LIFT) is applied as printing technology to draw new concepts for sophisticated model electrode architectures with advanced electrochemical performances. Finally, the micro-/nano-scaled texturing of current collectors and separator material is discussed as further possible approaches for boosting the electrochemical performances of LIB pouch cells.
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Chen, Ting, Kwati Leonard, Kazunari Sasaki, Hiroshige Matsumoto, and Nicola H. Perry. "Tailoring Chemical Expansion in Zirconate-Cerate Proton Conductors." ECS Meeting Abstracts MA2018-01, no. 32 (April 13, 2018): 1934. http://dx.doi.org/10.1149/ma2018-01/32/1934.
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Stoichiometric chemical expansion is the lattice expansion accompanying non-integer changes in stoichiometry, such as oxygen loss in mixed ionic and electronic conducting oxides, Li intercalation in battery electrodes, H uptake in hydrogen storage materials, or hydration in proton conductors. The coefficient of chemical expansion (CCE) normalizes this chemical strain (εC) to the compositional change, so for the case of hydration in proton conductors it can be defined as CCE = εC/Δ[(OH)• O]. The chemical stresses that develop from such compositional changes can be large enough to cause mechanical failure, such as cracking or delamination, with implications for component processing, in situ characterization, and device lifetime. One way to lower the magnitude of chemical stress is to engineer materials with lower CCEs, but relatively few design principles exist to guide such engineering. In the present work we investigated the hypothesis that lower crystal symmetry could lead to lower macroscopic CCEs in polycrystalline ceramics. There are indications that such a correlation may exist among mixed ionic and electronic conducting perovskites that expand upon losing oxygen due to enlargement of multivalent cations upon gaining electrons for charge compensation. To examine whether a similar effect may be present also for the case of hydration-induced expansion, which has a different mechanism involving filling of oxygen vacancies and introduction of interstitial hydrogen, we fabricated a series of perovskite-structured proton conductors, BaY0.1Ce0.9-xZrxO3 (x=0, 0.3, 0.6, 0.9), having tailored tolerance factors – an indicator of symmetry. Bar-shaped samples were prepared by a sol-gel route and sintering to 1500 °C, and their crystal structures and lattice parameters were analyzed by X-ray diffraction with Rietveld analysis. For each composition, the isothermal expansion upon increasing H2O content in the gas atmosphere by a fixed amount was measured by dilatometry at various temperatures up to 680 °C. The corresponding changes in (OH)• O content were determined by thermogravimetric analysis under the same conditions. By normalizing the chemical strains to the changes in proton content, the CCEs at each temperature were determined for each composition and compared. X-ray diffraction confirmed that the crystal structure became more cubic and the symmetry increased with increasing x, as expected on the basis of the calculated tolerance factors. At the same time the unit cell volume increased, which could also in principle contribute to modifying the chemical expansion behavior. Proton uptake (for a given steam content) was smaller for higher x values, but the lower proton uptake did not correspond with the smallest chemical strains. In fact, the normalized CCEs monotonically increased with increasing x for all but the highest temperatures, consistent with the hypothesis of higher CCEs for higher symmetry, for these randomly oriented, polycrystalline samples. These results suggest that lowering symmetry may be a promising approach for minimizing chemical expansion behavior across multiple classes of materials, with the potential to improve material and device durability. At the same time, future studies should aim to separate the effects of unit cell size vs. crystal symmetry.
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Arnold, Stefanie, Antonio Gentile, Yunjie Li, Qingsong Wang, Stefano Marchionna, Riccardo Ruffo, and Volker Presser. "(Digital Presentation) Design of High-Performance Antimony / MXene Hybrid Electrodes for Sodium-Ion Batteries." ECS Meeting Abstracts MA2022-01, no. 1 (July 7, 2022): 97. http://dx.doi.org/10.1149/ma2022-01197mtgabs.
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As a result of the growing electrification and the ever-increasing demand for batteries, scarcity of fossil resources of lithium, and the resulting rise in price, energy storage technologies beyond lithium aroused high interest throughout the past years.1-3 Sodium is a naturally abundant element in the earth and therefore offers the opportunity to develop a promising low-cost, large-scale energy application with favorable energy and power densities. Recently, frequent new and further developments on the anode and cathode materials for sodium-ion batteries have been made. In particular, the development of anode material presents massive challenge while several requirements of high capacity and long lifetime/high durability need to be fulfilled. The unique properties of the novel 2D material MXene, including their excellent electrical conductivity and accessible interlayer space, enable them to be used as attractive electrode materials for battery and supercapacitor. Still, a major drawback is that the capacity of Na+-ion storage by intercalation chemistry is limited due to the limited storage sites.4 As it comes to high-capacity materials, the research field of conversion and alloying materials provides highly attractive candidates. For example, antimony is a promising anode candidate, which undergoes alloying reaction with sodium to form Na3Sb, delivering a high theoretical capacity of 660 mAh g-1. Still, the major drawback of alloying materials is the high volume changes during sodiation and de-sodiation which often leads to electrode cracking, pulverization, continuous reformation of SEI and thus results in poor electrochemical performance. It is, therefore, highly promising to combine both, MXene and antimony for stable, high performance energy storage. Our work explores the best strategy to achieve Sb/MXene hybrid electrodes. There is a tremendous influence in the electrochemical performance dependent on Sb-to-MXene ratio, Sb distribution, and Sb/MXene entanglement. The optimized performance does not align with the highest amount of antimony, the smallest nanoparticles, or the largest interlayer distance of the MXene but by the most homogeneous distribution of antimony and MXene while both components remain electrochemically addressable. With the best optimized hybrid material, we obtained electrodes showing a specific capacity of 450 mAh g-1 at 0.1 A g-1 and 365 mAh g-1 at 4 A g-1, with capacity retention of around 96% after 100 cycles. References Perveen, T.; Siddiq, M.; Shahzad, N.; Ihsan, R.; Ahmad, A.; Shahzad, M. I., Prospects in anode materials for sodium ion batteries-A review. Renewable and Sustainable Energy Reviews 2020, 119, 109549. Skundin, A.; Kulova, T.; Yaroslavtsev, A., Sodium-ion batteries (a review). Russian Journal of Electrochemistry 2018, 54 (2), 113-152. Kundu, D.; Talaie, E.; Duffort, V.; Nazar, L. F., The emerging chemistry of sodium ion batteries for electrochemical energy storage. Angewandte Chemie International Edition 2015, 54 (11), 3431-3448. Kim, Y.; Ha, K. H.; Oh, S. M.; Lee, K. T., High‐capacity anode materials for sodium‐ion batteries. Chemistry–A European Journal 2014, 20 (38), 11980-11992. Figure: De-sodiation capacity and Coulombic efficiency versus cycle number of a simple mechanical mixed antimony MXene electrode (pink) and optimized hybrid material (blue). Figure 1
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Lee, Sang-Min, Junyoung Kim, Janghyuk Moon, Kyu-Nam Jung, Jong Hwa Kim, Gum-Jae Park, Jeong-Hee Choi, et al. "A cooperative biphasic MoOx–MoPx promoter enables a fast-charging lithium-ion battery." Nature Communications 12, no. 1 (January 4, 2021). http://dx.doi.org/10.1038/s41467-020-20297-8.
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AbstractThe realisation of fast-charging lithium-ion batteries with long cycle lifetimes is hindered by the uncontrollable plating of metallic Li on the graphite anode during high-rate charging. Here we report that surface engineering of graphite with a cooperative biphasic MoOx–MoPx promoter improves the charging rate and suppresses Li plating without compromising energy density. We design and synthesise MoOx–MoPx/graphite via controllable and scalable surface engineering, i.e., the deposition of a MoOx nanolayer on the graphite surface, followed by vapour-induced partial phase transformation of MoOx to MoPx. A variety of analytical studies combined with thermodynamic calculations demonstrate that MoOx effectively mitigates the formation of resistive films on the graphite surface, while MoPx hosts Li+ at relatively high potentials via a fast intercalation reaction and plays a dominant role in lowering the Li+ adsorption energy. The MoOx–MoPx/graphite anode exhibits a fast-charging capability (<10 min charging for 80% of the capacity) and stable cycling performance without any signs of Li plating over 300 cycles when coupled with a LiNi0.6Co0.2Mn0.2O2 cathode. Thus, the developed approach paves the way to the design of advanced anode materials for fast-charging Li-ion batteries.
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Bhandari, Arihant, Chao Peng, Jacek Dziedzic, John R. Owen, Denis Kramer, and Chris-Kriton Skylaris. "Li nucleation on the graphite anode under potential control in Li-ion batteries." Journal of Materials Chemistry A, 2022. http://dx.doi.org/10.1039/d2ta02420a.
Full textAbstract:
Application of Li-ion batteries in electric vehicles requires improved safety, increased lifetime and high charging rates. One of the most commonly used intercalation anode material for Li-ion batteries, graphite, is...