Journal articles on the topic 'Ionic transport properties correlations'
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Sohn, Ahrum, and Choongho Yu. "Ionic transport properties and their empirical correlations for thermal-to-electrical energy conversion." Materials Today Physics 19 (July 2021): 100433. http://dx.doi.org/10.1016/j.mtphys.2021.100433.
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Lan, Tian, Francesca Soavi, Massimo Marcaccio, Pierre-Louis Brunner, Jonathan Sayago, and Clara Santato. "Electrolyte-gated transistors based on phenyl-C61-butyric acid methyl ester (PCBM) films: bridging redox properties, charge carrier transport and device performance." Chemical Communications 54, no. 43 (2018): 5490–93. http://dx.doi.org/10.1039/c8cc03090a.
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Liu, Baichuan, Nicole James, Dean Wheeler, and Brian A. Mazzeo. "Effect of Calendering on Local Ionic and Electronic Transport of Porus Electrodes." ECS Meeting Abstracts MA2022-02, no. 6 (October 9, 2022): 612. http://dx.doi.org/10.1149/ma2022-026612mtgabs.
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The microstructure determines transport properties in lithium-ion battery electrodes. There is generally a tradeoff between electronic and ionic transport when adjusting the microstructure. One way of adjusting the microstructure is through calendering, where the electrode is compressed following drying. Understanding how calendering affects not only the average but also the local electronic and ionic transport provides additional insight when developing battery electrodes and engineering better batteries. If a correlation exists between the two properties, an optimal porosity that maximizes both ionic and electronic transport could be determined. In order to better understand the influence of microstructure on these transport properties, we tested a series of commercial-grade electrodes including NMC cathodes, graphite anodes, and a graphite-silicon anode. The local electronic conductivity of the electrodes was found using a micro-flexible-surface probe previously developed by our research group [1]. Likewise, the local ionic conductivity was found using an aperture probe previously developed by our research group [2]. All electrodes were obtained from Argonne National Laboratory in calendered and un-calendered states. Through testing various electrodes before and after calendering, we found that not every electrode experienced an increase in electronic conductivity after calendering, and that in general heterogeneity of the electronic conductivity decreased after calendering. The local ionic resistance, as indicated by MacMullin number, was found to increase after calendering, as expected. Figure 1 illustrates the local ionic and electronic transport results for one cathode. Ionic transport was found to be almost solely influenced by porosity. However, electronic transport was found to be influenced by a variety of factors including the nature, distribution, and connectivity of conductive materials. [1] Vogel et al., J. Electrochem. Soc. 168, 100504 (2021). [2] Liu et al., ECS Meeting Abstracts 2021, 444. Figure 1
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Gautam, Ajay, and Marnix Wagemaker. "Lithium Distribution and Site Disorder in Halide-Substituted Lithium Argyrodites: A Structural and Transport Study." ECS Meeting Abstracts MA2023-02, no. 8 (December 22, 2023): 3325. http://dx.doi.org/10.1149/ma2023-0283325mtgabs.
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Lithium argyrodite superionic conductor has recently gained significant attention as a potential solid electrolyte for all-solid-state batteries because of its high ionic conductivity and ease of processing. One promising aspect of these materials is the ability to introduce halide (Li6-xPS5-xY1+x, Y = Cl and Br ) into the crystal structure, which can greatly impact the lithium distribution over the wide range of accessible sites and structural site-disorder between the S2₋ and Y₋ anion on Wyckoff 4d site, strongly influences the ionic conductivity. However, the relationship between halide substitution, structural site-disorder, and lithium distribution is not fully understood. In this study, we investigate the effect of halide substitution on lithium argyrodite and engineer site-disorder by changing the synthesis protocol. We reveal the lithium substructure and ionic transport correlations using neutron diffraction, solid-state NMR, and electrochemical impedance spectroscopy, We find that higher ionic conductivity is correlated with a negative charge on the 4d site, as replacing the S2− with Br− leads to a lowered average charge on the 4d site and weaker interactions within the Li+ “cage”, promoting a migration pathway for Li+ ions across the Li+ cage. We also identify a new T4 Li+ site, which enables an alternative jump route (T5–T4–T5) with a lower migration energy barrier. The resulting expansion of Li+ cages and increased connections between cages leads to a maximum ionic conductivity of 8.55 mS cm-1 with higher site-disorder, an improvement of 11-fold compared to lower site-disorder. Overall, this work provides a deeper understanding of the structure-transport correlations in lithium argyrodite, specifically how site-disorder and halide substitution impact the lithium substructure and transport properties.
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Silva, Wagner, Marcileia Zanatta, Ana Sofia Ferreira, Marta C. Corvo, and Eurico J. Cabrita. "Revisiting Ionic Liquid Structure-Property Relationship: A Critical Analysis." International Journal of Molecular Sciences 21, no. 20 (October 19, 2020): 7745. http://dx.doi.org/10.3390/ijms21207745.
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In the last few years, ionic liquids (ILs) have been the focus of extensive studies concerning the relationship between structure and properties and how this impacts their application. Despite a large number of studies, several topics remain controversial or not fully answered, such as: the existence of ion pairs, the concept of free volume and the effect of water and its implications in the modulation of ILs physicochemical properties. In this paper, we present a critical review of state-of-the-art literature regarding structure–property relationship of ILs, we re-examine analytical theories on the structure–property correlations and present new perspectives based on the existing data. The interrelation between transport properties (viscosity, diffusion, conductivity) of IL structure and free volume are analysed and discussed at a molecular level. In addition, we demonstrate how the analysis of microscopic features (particularly using NMR-derived data) can be used to explain and predict macroscopic properties, reaching new perspectives on the properties and application of ILs.
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Hoffmann, Maxi, Ciprian Iacob, Gina Kaysan, Mira Simmler, Hermann Nirschl, Gisela Guthausen, and Manfred Wilhelm. "Charge Transport and Glassy Dynamics in Blends Based on 1-Butyl-3-vinylbenzylimidazolium Bis(trifluoromethanesulfonyl)imide Ionic Liquid and the Corresponding Polymer." Polymers 14, no. 12 (June 15, 2022): 2423. http://dx.doi.org/10.3390/polym14122423.
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Charge transport, diffusion properties, and glassy dynamics of blends of imidazolium-based ionic liquid (IL) and the corresponding polymer (polyIL) were examined by Pulsed-Field-Gradient Nuclear Magnetic Resonance (PFG-NMR) and rheology coupled with broadband dielectric spectroscopy (rheo-BDS). We found that the mechanical storage modulus (G′) increases with an increasing amount of polyIL and G′ is a factor of 10,000 higher for the polyIL compared to the monomer (GIL′= 7.5 Pa at 100 rad s−1 and 298 K). Furthermore, the ionic conductivity (σ0) of the IL is a factor 1000 higher than its value for the polymerized monomer with 3.4×10−4 S cm−1 at 298 K. Additionally, we found the Haven Ratio (HR) obtained through PFG-NMR and BDS measurements to be constant around a value of 1.4 for the IL and blends with 30 wt% and 70 wt% polyIL. These results show that blending of the components does not have a strong impact on the charge transport compared to the charge transport in the pure IL at room temperature, but blending results in substantial modifications of the mechanical properties. Furthermore, it is highlighted that the increase in σ0 might be attributed to the addition of a more mobile phase, which also possibly reduces ion-ion correlations in the polyIL.
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Westover, Andrew S., Farhan Nur Shabab, John W. Tian, Shivaprem Bernath, Landon Oakes, William R. Erwin, Rachel Carter, Rizia Bardhan, and Cary L. Pint. "Stretching Ion Conducting Polymer Electrolytes: In-Situ Correlation of Mechanical, Ionic Transport, and Optical Properties." Journal of The Electrochemical Society 161, no. 6 (2014): E112—E117. http://dx.doi.org/10.1149/2.035406jes.
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Zhang, Yong, and Edward J. Maginn. "Direct Correlation between Ionic Liquid Transport Properties and Ion Pair Lifetimes: A Molecular Dynamics Study." Journal of Physical Chemistry Letters 6, no. 4 (February 5, 2015): 700–705. http://dx.doi.org/10.1021/acs.jpclett.5b00003.
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Mohamed, Hamdy F. M., Esam E. Abdel-Hady, and Wael M. Mohammed. "Investigation of Transport Mechanism and Nanostructure of Nylon-6,6/PVA Blend Polymers." Polymers 15, no. 1 (December 27, 2022): 107. http://dx.doi.org/10.3390/polym15010107.
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A casting technique was used to prepare poly(vinyl alcohol) (PVA) blend polymers with different concentrations of Nylon-6,6 to increase the free-volume size and control the ionic conductivity of the blended polymers. The thermal activation energy for some blends is lower than that of pure polymers, indicating that their thermal stability is somewhere in between that of pure Nylon-6,6 and pure PVA. The degree of crystallinity of the blend sample (25.7%) was lower than that of the pure components (41.0 and 31.6% for pure Nylon-6,6 and PVA, respectively). The dielectric properties of the blended samples were investigated for different frequencies (50 Hz–5 MHz). The σac versus frequency was found to obey Jonscher’s universal power law. The calculated values of the s parameter were increased from 0.53 to 0.783 for 0 and 100 wt.% Nylon-6,6, respectively, and values less than 1 indicate the hopping conduction mechanism. The barrier height (Wm) was found to increase from 0.33 to 0.72 for 0 and 100 wt.% Nylon-6,6, respectively. The ionic conductivity decreases as the concentration of Nylon-6,6 is blended into PVA because increasing the Nylon-6,6 concentration reduces the number of mobile charge carriers. Positron annihilation lifetime (PAL) spectroscopy was used to investigate the free volume’s nanostructure. The hole volume size grows exponentially with the concentration of Nylon-6,6 mixed with PVA. The Nylon-6,6/PVA blends’ free-volume distribution indicates that there is no phase separation in the blended samples. Mixing PVA and Nylon-6,6 resulted in a negative deviation (miscible blends), as evidenced by the interaction parameter’s negative value. The strong correlation between the free-volume size and other macroscopic properties like ionic conductivity suggests that the free-volume size influences these macroscopic properties.
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OSUCHOWSKI, MARCIN, and JANUSZ PŁOCHARSKI. "ELECTRORHEOLOGICAL EFFECT IN SUSPENSIONS OF AgI/Ag2O/V2O5/P2O5 GLASSES." International Journal of Modern Physics B 16, no. 17n18 (July 20, 2002): 2378–84. http://dx.doi.org/10.1142/s0217979202012396.
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The ER effect results from bulk and surface electric polarization processes in solid grains of ER suspensions but detailed mechanisms are not very clear. The aim of the present study was to find correlations between the character of bulk charge transport processes (electronic and/or ionic) in particles of a dispersion and parameters of the ER effect. As the dispersed phase we used glasses comprising oxides of silver, vanadium and phosphorus with addition of silver iodide. Bulk electric properties of this material could be modified without changing other properties influencing the ER effect like porosity, shape of grains, hardness, affinity to a liquid matrix etc. Variations of concentration of the components result in changes of ionic and electronic conductivity whilst other properties remain constant. The suspensions of the powdered glasses showed relatively high ER effect. The dynamic yield stress figured from 35 to 160 Pa at 2.0kV/mm for 12% concentration by volume. The highest values were observed for ionically conducting samples. The values of relaxation frequencies ( f R ) based on bulk properties of the glass sample were calculated and correlated with the yield stress whose maximum was obtained for samples of f R close to 100 kHz. High ER effect was observed also for samples of f R in the MHz range but in this case different polarization mechanism was postulated. The influence of polarization mechanisms on rheological behavior of the prepared fluids was discussed.
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Sacci, Robert L., Tyler H. Bennett, Kee Sung Han, Hong Fang, Puru Jena, Vijay Murugesan, and Jagjit Nanda. "How Halide Sub-Lattice Affects Li Ion Transport in Antiperovskites." ECS Meeting Abstracts MA2022-02, no. 4 (October 9, 2022): 467. http://dx.doi.org/10.1149/ma2022-024467mtgabs.
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Li-based antiperovskites (LiAP, Li3-x OH x X, X = Cl, Br) are an emergent class of Li-ion conductors that are potential candidates for electrolytes in all-solid-state batteries. As a material class, pLiAP shows vast compositional design freedom; however, the resulting properties are susceptible to synthesis and processing methodologies. For example, proton incorporation and halide mixing stabilize the perovskite cubic phase near room temperature, and halides mixtures near the eutectic points drive the solid-state reaction temperature down, allowing for faster synthesis and processing conditions (< 1 h). The mixed halogen compositions, such as Li2OHCl0.37Br0.63, also show a 30-fold improvement in room temperature ionic conductivity of a single halide structure, 1.5 x 10-6 vs. 4.9 x 10-8 S cm-1 (Li2OHCl). Despite the growing interest in these materials, important questions remain about LiAPs on the structure-property correlation upon halide substitution and the correlations between the OH/halide dynamics and the Li-ion transport. We thus attempted to deconvolute how proton dynamics and halide substitution enhance or impede ionic conduction in pLiAP at compositions near the halide salts' eutectic points. We combined infrared spectroscopy and nuclear magnetic resonance (NMR) with first-principles density functional theory (DFT) calculations to deconvolute halide mixing effects from local proton dynamics on Li-ion transport. The NMR results and ab initio molecular dynamics suggest that Li+ transport is more strongly correlated with halide dynamics. While the hydroxide does stabilize the highly conductive cubic structure, it limits correlative ionic transport and thus lowers Li+ conductivity. Experiment design, data analysis, and manuscript preparation (RLS) were supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering. Synthesis (THB and JN) were supported by Asst. Secretary, Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (VTO) through the Advanced Battery Materials Research (BMR) Program. P. J. acknowledges partial support by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-FG02-96ER45579. H. F. was supported from U.S. Department of Energy (Award No. DE-EE0008865). This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The NMR characterization part of the work is supported by the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, and Basic Energy Sciences. The NMR work was performed at the W. R. Wiley Environmental Molecular Sciences Laboratory, a DOE User Facility sponsored by the Office of Biological and Environmental Research, located at Pacific Northwest National Laboratory. Figure 1
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Pan, Ruiguang, Alexander P. Gysi, Artas Migdisov, Lei Gong, Peng Lu, and Chen Zhu. "Linear Correlations of Gibbs Free Energy of REE Phosphates (Monazite, Xenotime, and Rhabdophane) and Internally Consistent Binary Mixing Properties." Minerals 14, no. 3 (March 14, 2024): 305. http://dx.doi.org/10.3390/min14030305.
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Rare Earth Elements (REE) phosphates (monazite, xenotime, and rhabdophane) are critical REE-bearing minerals typically formed in hydrothermal and magmatic ore deposits. The thermodynamic properties of those REE minerals are crucial to understanding the solubility, speciation, and transport of REE complexes. However, the standard-state Gibbs free energy of formation (∆G°f) values reported for these minerals in the literature vary by up to 25 kJ mol−1. Here, we present linear free energy relationships that allow the evaluation and estimation of the ∆G°f values at 25 °C and 1 bar for the three minerals from the ionic radius (rREE3+) and the non-solvation Gibbs free energy contribution to the REE3+ aqua ion (∆G°n, REE3+): ∆G°f,monazite − 399.71 rREE3+ = 1.0059 ∆G°n,REE3+ − 2522.51; ∆G°f,xenotime − 344.08 rREE3+ = 0.9909 ∆G°n,REE3+ − 2451.53; and ∆G°f,rhabdophane − 416.17 rREE3+ = 1.0067 ∆G°n, REE3+ − 2688.86. Moreover, based on the new dataset derived for REE end-members, we re-fitted the binary Margules parameter (W) from previous theoretical calculations into linear correlations: W + 0.00204 ∆G°’n,monazite = 39.3549 ∆V + 0.0641; W + 0.00255 ∆G°’n,xenotime = 25.4885 ∆V − 0.0062. The internally consistent thermodynamic properties of these REE phosphates are incorporated into the computer program Supcrtbl, which is available online at Zhu’s research website.
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Harris, Kenneth R., and Mitsuhiro Kanakubo. "Self-diffusion, velocity cross-correlation, distinct diffusion and resistance coefficients of the ionic liquid [BMIM][Tf2N] at high pressure." Physical Chemistry Chemical Physics 17, no. 37 (2015): 23977–93. http://dx.doi.org/10.1039/c5cp04277a.
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Distinct diffusion coefficients for 1-alkyl-3-imidazolium [Tf2N] salts show very similar viscosity dependence; thermodynamic scaling parameters for the reduced transport properties are equal.
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Kiyohara, Kenji, and Minagi Tamura. "Transport coefficients of gel electrolytes: A molecular dynamics simulation study." Journal of Chemical Physics 156, no. 8 (February 28, 2022): 084905. http://dx.doi.org/10.1063/5.0081118.
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The responses of gel electrolytes to stimuli make them useful in applications such as sensors and actuators. However, few studies have explored their transport properties from a molecular viewpoint. We studied the transport coefficients of gel electrolytes based on perfluorinated sulfonic acid using molecular dynamics simulations. The transport coefficients for electric and pressure fields, namely, the ionic conductivity, Darcy permeability, and cross coupling constant, were calculated based on Kubo’s linear response theory from the corresponding velocity correlation functions and mean square displacements. The effects of the water content of the gel electrolyte and those of the monovalent cationic species were also analyzed. The calculated transport coefficients qualitatively agree with the reported experimental results. The role of the cross coupling constants in determining the functional efficiency of gel electrolytes as pressure sensors or electroactive actuators is discussed.
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Friess, Karel, Johannes Carolus Jansen, Fabio Bazzarelli, Pavel Izák, Veronika Jarmarová, Marie Kačírková, Jan Schauer, Gabriele Clarizia, and Paola Bernardo. "High ionic liquid content polymeric gel membranes: Correlation of membrane structure with gas and vapour transport properties." Journal of Membrane Science 415-416 (October 2012): 801–9. http://dx.doi.org/10.1016/j.memsci.2012.05.072.
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Bernasconi, Andrea, Cristina Tealdi, and Lorenzo Malavasi. "High-Temperature Structural Evolution in the Ba3Mo(1–x)WxNbO8.5 System and Correlation with Ionic Transport Properties." Inorganic Chemistry 57, no. 11 (May 24, 2018): 6746–52. http://dx.doi.org/10.1021/acs.inorgchem.8b01093.
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Lesnichyova, Alyona, Anna Stroeva, Semyon Belyakov, Andrey Farlenkov, Nikita Shevyrev, Maksim Plekhanov, Igor Khromushin, Tatyana Aksenova, Maxim Ananyev, and Anton Kuzmin. "Water Uptake and Transport Properties of La1−xCaxScO3−α Proton-Conducting Oxides." Materials 12, no. 14 (July 10, 2019): 2219. http://dx.doi.org/10.3390/ma12142219.
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In this study, oxide materials La1−xCaxScO3−α (x = 0.03, 0.05 and 0.10) were synthesized by the citric-nitrate combustion method. Single-phase solid solutions were obtained in the case of calcium content x = 0.03 and 0.05, whereas a calcium-enriched impurity phase was found at x = 0.10. Water uptake and release were studied by means of thermogravimetric analysis, thermodesorption spectroscopy and dilatometry. It was shown that lower calcium content in the main phase leads to a decrease in the water uptake. Conductivity was measured by four-probe direct current (DC) and two-probe ascension current (AC) methods at different temperatures, pO2 and pH2O. The effects of phase composition, microstructure and defect structure on electrical conductivity, as well as correlation between conductivity and water uptake experiments, were discussed. The contribution of ionic conductivity of La1−xCaxScO3−α rises with decreasing temperature and increasing humidity. The domination of proton conductivity at temperatures below 500 °C under oxidizing and reducing atmospheres is exhibited. Water uptake and release as well as transport properties of La1−xCaxScO3−α are compared with the properties of similar proton electrolytes, La1−xSrxScO3−α, and the possible reasons for their differences were discussed.
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Trullas, J., and A. Giro. "Potentials and correlation functions for the copper halide and silver iodide melts. II. Time correlation functions and ionic transport properties." Journal of Physics: Condensed Matter 2, no. 31 (August 6, 1990): 6643–50. http://dx.doi.org/10.1088/0953-8984/2/31/017.
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Mazuki, N. F., M. Z. Kufian, Y. Nagao, and A. S. Samsudin. "Correlation Studies Between Structural and Ionic Transport Properties of Lithium-Ion Hybrid Gel Polymer Electrolytes Based PMMA-PLA." Journal of Polymers and the Environment 30, no. 5 (October 28, 2021): 1864–79. http://dx.doi.org/10.1007/s10924-021-02317-w.
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Safronova, Ekaterina Yu, Daria Yu Voropaeva, Dmitry V. Safronov, Nastasia Stretton, Anna V. Parshina, and Andrey B. Yaroslavtsev. "Correlation between Nafion Morphology in Various Dispersion Liquids and Properties of the Cast Membranes." Membranes 13, no. 1 (December 22, 2022): 13. http://dx.doi.org/10.3390/membranes13010013.
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Nafion is a perfluorosulfonic acid polymer that is most commonly used in proton-exchange membrane fuel cells. The processes of pretreatment and formation of such membranes strongly affect their properties. In this work, dispersions of Nafion in various ionic forms and dispersing liquids (ethylene glycol, N,N-dimethylformamide, N-methyl-2-pyrrolidone and isopropyl alcohol–water mixtures in different ratios) were obtained and studied. Membranes fabricated by casting of the various dispersions were also studied. The effect of the nature of the dispersing liquid and the counterion on the properties of Nafion dispersions, the morphology of the polymer in the dispersions and the characteristics of the membranes obtained from them has been shown. Based on the overall results, it can be concluded that the use of perfluorosulfonic acid dispersions in aprotic polar solvents is advisable for obtaining membranes by the casting procedure. This is because it provides optimal polymer morphology in the dispersion, which leads to the formation of films with good selectivity, mechanical and transport properties. The performed investigations show the relationship between the composition of dispersions, the morphology of the polymer and the properties of the membranes formed from them by the casting procedure.
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Ji, Chao, Tuo Li, Xiaofeng Zou, and Lu Zhang. "Transport Layer Optimization Strategy to Prepare High Efficiency Perovskite Photovoltaic Device." Journal of Physics: Conference Series 2356, no. 1 (October 1, 2022): 012020. http://dx.doi.org/10.1088/1742-6596/2356/1/012020.
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Perovskite photovoltaic devices have attracted widespread attention. Despite the spectacular advances in power conversion efficiency (PCE), the unsatisfying stability of the perovskite devices is still a great challenge, which requires a deeper understanding of the device physics, in particular, the interfacial behavior and the junction structure of the perovskite semiconductor devices. Here we demonstrate the continuous decrease of ionic interface charge (IIC) density, weakening of current-voltage hysteresis, decrease of leakage current as well as constant increase of PCE from ~10% to ~19% were achieved through step-by-step modification of the hole transport layer (HTL) and electron transport layer (ETL) of the devices. A new semiconductor device junction device model is presented to understand the correlation between the IIC density and the photovoltaic performance. The work shows that although the IIC is originated from mobile ions in perovskite layer, the IIC density is determined by the properties of the charge transport layer. These conclusions and the proposed device model have important implication for future study in pursuing efficient and stable perovskite photovoltaic devices.
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Bergstrom, Helen K., Kara D. Fong, and Bryan D. McCloskey. "The Role of Ion-Correlation in Reducing the Lithium Transference Number in Lithium-Ion Polyelectrolyte Solutions." ECS Meeting Abstracts MA2022-02, no. 3 (October 9, 2022): 203. http://dx.doi.org/10.1149/ma2022-023203mtgabs.
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Non-aqueous polyelectrolyte solutions (PESs) have been suggested as a promising route to high conductivity, high transference number (t+) electrolytes.1–3 State-of-the-art liquid electrolytes suffer from low t+, meaning the majority of ionic conductivity results from motion of the anion rather than the electrochemically active Li+ ion. Increasing t+ requires decreasing the mobility of the anion, which is dictated by both the diffusion of the anion as well as its net charge. PESs are intuitively appealing because anchoring the anion to a polymer backbone slows down the motion of the electrochemically inactive anion while maintaining higher ion conductivity through improved ion dissociation and solvent-mediated Li+ transport. However, in polyelectrolyte systems, increasing molecular weight both decreases polymer diffusion and increases charge, which will act as competing effects for t+.Recent molecular dynamic simulations of PESs have highlighted the critical importance of correlated ion motion in these systems and have called into question oligomeric PESs as a feasible strategy to achieving high t+ and conductivity electrolytes4,5 In this work we discuss complete studies of transport properties in lithium-ion and lithium metal battery-relevant PESs- specifically lithium triflimide appended polystyrene (PS-LiTFSI) and polymethacrylate (PM-LiTFSI) dissolved in carbonate blends. All prior PES experimental work in the literature has relied on ideal solution assumptions for measuring transport properties. This work represents the first rigorous characterization of transport properties for a battery-relevant polyelectrolyte solution. Using electrophoretic NMR and electrochemical experiments, we characterized the transport properties, including the electrophoretic ion mobilities, conductivity, diffusion coefficients, and t+ of these model PESs. While previous studies that rely on ideal assumptions predict that PESs will have higher t+ than monomeric solutions, we demonstrate that below the entanglement limit, t+ decreases with increasing degree of polymerization. For higher degrees of polymerization, we directly observe Li+ move in the “wrong direction” in an electric field, evidence of a negative transference number due to correlated motion through ion clustering. Using calculated Onsager transport coefficients and insights from molecular dynamics modeling, we demonstrate that despite selectively slowing anion motion using polyanions, anion-anion correlation through the polymer backbone and cation-anion correlation through ion aggregates reduce the t+ in non-entangled PESs. References Diederichsen, K. M. et al. ACS Energy Lett. (2017). Diederichsen, K. M. et al. Macromolecules (2018). Dewing, B. L., et al. Chem. Mater. (2020). Fong, K. D. et al. ACS Cent. Sci. (2019). Fong, K. D., et al. Macromolecules (2020).
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Massardo, Sara, Alessandro Cingolani, and Cristina Artini. "High Pressure X-ray Diffraction as a Tool for Designing Doped Ceria Thin Films Electrolytes." Coatings 11, no. 6 (June 16, 2021): 724. http://dx.doi.org/10.3390/coatings11060724.
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Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films.
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Komayko, Alena I., Ekaterina A. Arkhipova, Anton S. Ivanov, Konstantin I. Maslakov, Stepan Yu Kupreenko, Hui Xia, Serguei V. Savilov, and Valery V. Lunin. "Conductivity of N-(2-methoxyethyl)-substituted morpholinium- and piperidinium-based ionic liquids and their acetonitrile solutions." Functional Materials Letters 11, no. 06 (December 2018): 1840009. http://dx.doi.org/10.1142/s179360471840009x.
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N-ethyl-N-(2-methoxyethyl)-morpholinium bis(trifluoromethylsulfonyl)imide [Et(MEO)Mor][TFSI], N,N-bis(2-methoxyethyl)-morpholinium bis(trifluoromethylsulfonyl)imide [Bis(MEO)Mor][TFSI] and N,N-bis(2-methoxyethyl)-piperidinium bis(trifluoromethylsulfonyl)imide [Bis(MEO)Pip][TFSI] room-temperature ionic liquids (RTILs) were synthesized and their electrochemical properties were studied. Three stages of synthesis of RTILs were used, including the alkylation of secondary and tertiary amines and the anion exchange. The structure of RTILs was confirmed by 1H, [Formula: see text]C, H,H-COSY, 1H–[Formula: see text]C correlation spectroscopy NMR and XPS. Three main approaches based on the Arrhenius, Litovitz, and Vogel–Fulcher–Tammann equations were used to analyze the ion transport properties of RTILs. In addition, the electrical conductivity of the binary acetonitrile solutions of RTILs was studied. It was found that the activation energy and conductivity of RTILs depended on their polarity and ability to associate which affects the mobility of charge carriers and viscosity of the system.
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Montalbano, Michele, Daniele Callegari, Umberto Anselmi Tamburini, and Cristina Tealdi. "Design of Perovskite-Type Fluorides Cathodes for Na-ion Batteries: Correlation between Structure and Transport." Batteries 8, no. 9 (September 13, 2022): 126. http://dx.doi.org/10.3390/batteries8090126.
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Transition metal-based sodium fluoro-perovskite of general formula NaMF3 (M = Fe, Mn, and Co) were investigated as cathode materials for rechargeable Na-ion batteries. Preliminary results indicated Na-ion reversible intercalation but highlighted the need to find optimization strategies to improve conductivity and to modulate the operating voltages within experimentally accessible electrolytes’ stability windows, in order to fully exploit their potential as high-voltage cathodes. In this study, we combined experimental and computational techniques to investigate structures, defects, and intercalation properties of the NaFe1-xMnxF3 and NaCo1-xMnxF3 systems. Through the use of a simple solvothermal synthesis, we demonstrated the possibility to modulate the sample’s morphology in order to obtain fine and dispersed powder samples. The structural results indicated the formations of two solid solutions with a perovskite structure over the entire compositional range investigated. Atomistic simulations suggested that Na-ion diffusion in these systems was characterized by relatively high migration barriers and it was likely to follow three-dimensional paths, thus limiting the effect of anti-site defects. The correlation between structural and computational data highlighted the possibility to modulate both ionic and electronic conductivity as a function of the composition.
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Rizal, Danial Haziq, Wan Hasbullah Mohd Isa, Muhammad Amirul Abdullah, Ahmad Fakhri Ab Nasir, Anwar P.P. Abdul Majeed, and Norasmiza Mohd. "Effects of Varied Planar Dimensions of IPMC on Simulated Actuation using COMSOL." MEKATRONIKA 5, no. 2 (July 24, 2023): 1–5. http://dx.doi.org/10.15282/mekatronika.v5i2.9425.
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This study focuses on mechatronic systems and their use of bending smart materials, specifically the ionic polymer metal composite (IPMC), for compliant actuation. The advantages of IPMC actuators, such as low power consumption and high flexibility, are highlighted. The actuation mechanism of IPMCs involving ion migration, water transport, and mechanical stress imbalance is discussed. The influence of geometric parameters, specifically length and width, on IPMC performance is investigated through simulations. Results show a positive correlation between IPMC lengths exceeding 30 mm and displacement, with longer lengths leading to higher displacements. The relationship between width and maximum displacement is attributed to factors like increased active area, larger polymer volume, and potential effects on mechanical properties. Further electromechanical analysis is needed for a comprehensive understanding of these mechanisms.
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Stenina, Irina, Daniel Golubenko, Victor Nikonenko, and Andrey Yaroslavtsev. "Selectivity of Transport Processes in Ion-Exchange Membranes: Relationship with the Structure and Methods for Its Improvement." International Journal of Molecular Sciences 21, no. 15 (August 1, 2020): 5517. http://dx.doi.org/10.3390/ijms21155517.
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Nowadays, ion-exchange membranes have numerous applications in water desalination, electrolysis, chemistry, food, health, energy, environment and other fields. All of these applications require high selectivity of ion transfer, i.e., high membrane permselectivity. The transport properties of ion-exchange membranes are determined by their structure, composition and preparation method. For various applications, the selectivity of transfer processes can be characterized by different parameters, for example, by the transport number of counterions (permselectivity in electrodialysis) or by the ratio of ionic conductivity to the permeability of some gases (crossover in fuel cells). However, in most cases there is a correlation: the higher the flux density of the target component through the membrane, the lower the selectivity of the process. This correlation has two aspects: first, it follows from the membrane material properties, often expressed as the trade-off between membrane permeability and permselectivity; and, second, it is due to the concentration polarization phenomenon, which increases with an increase in the applied driving force. In this review, both aspects are considered. Recent research and progress in the membrane selectivity improvement, mainly including a number of approaches as crosslinking, nanoparticle doping, surface modification, and the use of special synthetic methods (e.g., synthesis of grafted membranes or membranes with a fairly rigid three-dimensional matrix) are summarized. These approaches are promising for the ion-exchange membranes synthesis for electrodialysis, alternative energy, and the valuable component extraction from natural or waste-water. Perspectives on future development in this research field are also discussed.
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Lufrano, Ernestino, Cataldo Simari, Maria Luisa Di Vona, Isabella Nicotera, and Riccardo Narducci. "How the Morphology of Nafion-Based Membranes Affects Proton Transport." Polymers 13, no. 3 (January 22, 2021): 359. http://dx.doi.org/10.3390/polym13030359.
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This work represents a systematic and in-depth study of how Nafion 1100 membrane preparation procedures affect both the morphology of the polymeric film and the proton transport properties of the electrolyte. The membrane preparation procedure has non-negligible consequences on the performance of the proton-exchange membrane fuel cells (PEMFC) that operate within a wide temperature range (up to 120 °C). A comparison between commercial membranes (Nafion 117 and Nafion 212) and Nafion membranes prepared by three different procedures, namely (a) Nafion-recast, (b) Nafion uncrystallized, and (c) Nafion 117-oriented, was conducted. Electrochemical Impedance Spectroscopy (EIS) and Pulsed-field gradient nuclear magnetic resonance (PFG-NMR) investigations indicated that an anisotropic morphology could be achieved when a Nafion 117 membrane was forced to expand between two fixed and nondeformable surfaces. This anisotropy increased from ~20% in the commercial membrane up to 106% in the pressed membrane, where the ionic clusters were averagely oriented (Nafion 117-oriented) parallel to the surface, leading to a strong directionality in proton transport. Among the membranes obtained by solution-cast, which generally exhibited isotropic proton transport behavior, the Nafion uncrystallized membrane showed the lowest water diffusion coefficients and conductivities, highlighting the correlation between low crystallinity and a more branched and tortuous structure of hydrophilic channels. Finally, the dynamic mechanical analysis (DMA) tests demonstrated the poor elastic modulus for both uncrystallized and oriented membranes, which should be avoided in high-temperature fuel cells.
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Ullah, Shahid, Hayat Ullah, Abdullah Yar, Sikander Azam, and A. Laref. "First-principles investigation of the electronic band structures and optical properties of quaternary ABaMQ4 (A = Rb, Cs; M = P, V; and Q = S) metal chalcogenides." International Journal of Modern Physics B 32, no. 30 (December 10, 2018): 1850337. http://dx.doi.org/10.1142/s021797921850337x.
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In this paper, we study the optoelectronic properties of quaternary metal chalcogenide semiconductor ABaMQ4 (A = Rb, Cs; M = P, V; and Q = S) compounds using state-of-the-art density functional theory (DFT) with TB-mBJ approximation for the treatment of exchange-correlation energy. In particular, the electronic and optical properties of the relaxed geometries of these compounds are investigated. Our first-principles ab-initio calculations show that the CsBaPS4 and RbBaPS4 compounds have direct bandgaps whereas the CsBaVS4 compound exhibits indirect bandgap nature. Importantly, the theoretically calculated values of the bandgaps of the compounds are consistent with experiment. Furthermore, our analysis of the electronic charge densities of these compounds indicates that the above quaternary chalcogenides have mixed covalent and ionic bonding characters. The effective masses of these compounds are also calculated which provide very useful information about the band structure and transport characteristics of the investigated compounds. Similarly, high absorptivity in the visible and ultraviolet regions of the electromagnetic spectrum possibly predicts and indicates the importance of these materials for potential optoelectronic applications in this range.
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Zhang, Hao, Feilong Xu, Xingyu Chen, and Wei Xia. "Unraveling the Correlation between Structure and Lithium Ionic Migration of Metal Halide Solid-State Electrolytes via Neutron Powder Diffraction." Batteries 9, no. 10 (October 15, 2023): 510. http://dx.doi.org/10.3390/batteries9100510.
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Metal halide solid-state electrolytes (SSEs) (Li-M-X system, typically Li3MX6 and Li2MX4; M is metal or rare-earth element, X is halogen) exhibit significant potential in all solid-state batteries (ASSB) due to wide stability windows (0.36–6.71 V vs. Li/Li+), excellent compatibility with cathodes, and a water-mediated facile synthesis route for large-scale fabrication. Understanding the dynamics of Li+ transportation and the influence of the host lattice is the prerequisite for developing advanced Metal halide SSEs. Neutron powder diffraction (NPD), as the most cutting-edge technology, could essentially reflect the nuclear density map to determine the whole crystal structure. Through NPD, the Li+ distribution and occupation are clearly revealed for transport pathway analysis, and the influence of the host ion lattice on Li+ migration could be discussed. In this review, we stress NPD utilization in metal halide SSEs systems in terms of defect chemistry, phase transition, cation/anion disorder effects, dual halogen, lattice dynamics/polarizability, and in situ analysis of phase evolution. The irreplaceable role of NPD technology in designing metal halide SSEs with enhanced properties is stressed, and a perspective on future developments of NPD in metal halide SSEs is also presented.
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Zaid, M., Malik Saadat Wali Khan, Rizwan Wahab, Manawwer Alam, Afroz Khan, and Naseem Ahmad. "Strong correlation of electrical transport and magnetic properties to ionic states, structure, and morphology of Al-substituted Ni–Co ferrite systems: A comprehensive study." Materials Today Chemistry 38 (June 2024): 102070. http://dx.doi.org/10.1016/j.mtchem.2024.102070.
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Chidiac, S. E., and H. Zibara. "Dry-cast concrete masonry products: properties and durabilityThis article is one of a selection of papers published in this Special Issue on Masonry." Canadian Journal of Civil Engineering 34, no. 11 (November 2007): 1413–23. http://dx.doi.org/10.1139/l07-072.
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Performance of dry-cast concrete masonry products (DCCMPs), which are becoming the product of choice for many applications, has yet to be assessed in a comprehensive manner. This study was undertaken to investigate the effects of mix design and manufacturing parameters on the mechanical and transport properties, as well as the freeze–thaw (F/T) durabilities, of DCCMPs. The variables studied were water to cement ratio, mixing time, vibration time, and curing regime. Freeze–thaw durability was assessed in accordance with the American Society for Testing and Materials (ASTM) standard C1262 by exposing specimens to four conditions: water, 3% NaCl, 4% CaCl2, and 4% MgCl2 solutions. Results revealed that 3% NaCl exposure yielded the most mass loss due to scaling, whereas 4% MgCl2 exposure exhibited the least. Increase in either water content, vibration time, mixing time, or use of moist curing led to improvement in the mechanical properties, refinement of large pores in the range of 40 to 400 μm, reduction of total porosity, and enhancement of F/T durability of capstones. Ionic sorptivity yielded a strong statistical correlation with mass loss due to F/T action in the presence of 3% NaCl and 4% CaCl2.
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Lew, Virgilio L., Nuala Daw, Zipora Etzion, Teresa Tiffert, Adaeze Muoma, Laura Vanagas, and Robert M. Bookchin. "Effects of age-dependent membrane transport changes on the homeostasis of senescent human red blood cells." Blood 110, no. 4 (August 15, 2007): 1334–42. http://dx.doi.org/10.1182/blood-2006-11-057232.
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Abstract Little is known about age-related changes in red blood cell (RBC) membrane transport and homeostasis. We investigated first whether the known large variation in plasma membrane Ca2+ (PMCA) pump activity was correlated with RBC age. Glycated hemoglobin, Hb A1c, was used as a reliable age marker for normal RBCs. We found an inverse correlation between PMCA strength and Hb A1c content, indicating that PMCA activity declines monotonically with RBC age. The previously described subpopulation of high-Na+, low-density RBCs had the highest Hb A1c levels, suggesting it represents a late homeostatic condition of senescent RBCs. Thus, the normal densification process of RBCs with age must undergo late reversal, requiring a membrane permeability increase with net NaCl gain exceeding KCl loss. Activation of a nonselective cation channel, Pcat, was considered the key link in this density reversal. Investigation of Pcat properties showed that its most powerful activator was increased intracellular Ca2+. Pcat was comparably selective to Na+, K+, choline, and N-methyl-D-glucamine, indicating a fairly large, poorly selective cation permeability pathway. Based on these observations, a working hypothesis is proposed to explain the mechanism of progressive RBC densification with age and of the late reversal to a low-density condition with altered ionic gradients.
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Khan, Md Sharif, Ambroise Van Roekeghem, Stefano Mossa, Flavien Ivol, Laurent Bernard, Lionel Picard, and Natalio Mingo. "Ionic Liquid Crystals As Solid Organic Electrolytes for Li-Ion Batteries: Experiments and Modeling." ECS Meeting Abstracts MA2022-01, no. 2 (July 7, 2022): 183. http://dx.doi.org/10.1149/ma2022-012183mtgabs.
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The development of the new electrolytes is essential to increase the energy density of the Li-ion batteries (LIBs)1. Solid electrolytes have attracted the interest of researchers as a next-generation electrolyte for LIBs due to their superior physical and chemical stability, large working potential windows, high transference number, and intrinsic safety2 3. In this study, we have designed and synthesized novel organic electrolytes for LIBs with a naphthalene mesogenic moiety bearing a lithium sulfonate group connected to two flexible long-alkyl chains. Starting from the lithium 4-aminonaphthalene-1-sulphonate building block, alkyl-tails were successfully doubly grafted on the amine function with N, N-di-isopropylethylamine in N, N-di-methylformamide. Once the reaction was completed, a washing, purification and neutralization step was carried out to obtain the desired product. Those electrolytes have been synthesized with 95 % purity as suggested from the NMR and mass spectrum. The chains length were differ by the number of alkyl groups in the chains from 8, 12, and 16, namely lithium 4 - (dioctylamino) naphthalene – 1 – sulfonate (BS-Li-8), lithium 4 - (didodecylamino) naphthalene – 1 - sulfonate (BS-Li-12), and lithium 4 - (dihexadecylamino) naphthalene – 1 – sulfonate (BS-Li-16). We have employed molecular dynamics simulations and various experimental techniques for a comprehensive understanding of the bulk structure and transport mechanism of those electrolytes. Simulated static structural factor, radial distribution functions, and experimental small angle x-ray scattering spectrum suggest that degree of aggregation, ionic correlations, and structural properties of materials at the nanoscale of the electrolyte molecules varies with the length of the alkyl chains. The Li+ ion mobility calculated from experimental Electrochemical Impedance Spectra, using a symmetrical cell with blocking electrodes and molecular dynamics simulations reveal that BS-Li-12 is the most conductive (approximately 10-3 S / cm at 1400 C) owing to the weaker cation-anion correlation than others. It was observed that the conductivity of the Li+ ions is directly related to the coordination number between Li+ and anionic centers, since, in BS-Li-12, Li+ coordinates with two anionic centers while for others, it is three. During the conduction, Li+ move from one anionic site to another by changing their coordination number with anion. We successfully synthesized next-generation organic electrolytes with well-organized Li+ conduction channels. The comprehensive study of the influence of the nonpolar alkyl chain on the bulk structural arrangement and conductivity of such electrolytes will contribute significantly to the development of future LIBs electrolytes. References: (1) Armand, M.; Tarascon, J.-M. Building Better Batteries. Nature 2008, 451 (7179), 652–657. https://doi.org/10.1038/451652a. (2) Manthiram, A.; Yu, X.; Wang, S. Lithium Battery Chemistries Enabled by Solid-State Electrolytes. Nature Reviews Materials 2017, 2 (4), 16103. https://doi.org/10.1038/natrevmats.2016.103. (3) Quartarone, E.; Mustarelli, P. Electrolytes for Solid-State Lithium Rechargeable Batteries: Recent Advances and Perspectives. Chem. Soc. Rev. 2011, 40 (5), 2525–2540. https://doi.org/10.1039/C0CS00081G. Figure 1
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Mewafy, Basma, Blanca I. Arias Serrano, Jan Wallis, Martin Rohloff, Javier Silva, Olga Ravkina, Robert Kircheisen, Ralf Kriegel, Jens Wartmann, and Angela Kruth. "Asymmetric Ba0.5Sr0.5Co0.8Fe0.2O3-Δ Membrane for Oxygen Permeation: Synergetic Fabrication By Magnetron Sputtering Deposition and Selective Laser Annealing." ECS Meeting Abstracts MA2022-02, no. 18 (October 9, 2022): 871. http://dx.doi.org/10.1149/ma2022-0218871mtgabs.
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The Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) mixed ionic electronic conductor (MIEC) is considered to be one of the most promising perovskite-based materials for oxygen transport exhibiting high oxygen permeability. Such oxygen-permeable perovskite membrane maybe applied to increase efficiency of combustion or reforming processes of new fuels such as green ammonia. An approach to elevate the oxygen permeability of BSCF membranes is reduction of membrane thickness, as the permeation process is mostly controlled by bulk diffusion. Since self-standing thin membranes are not sufficiently mechanically stable, asymmetric membranes consisting of a thin layer membrane deposited onto a porous bulk support are usually employed. . In this work, planar BSCF thin film membranes of 1 to 2 and 15 to 20 µm thickness were successfully synthesized by a combination of magnetron sputtering (MS) and thermal annealing (TA) and/or selective laser annealing (SLA) processes. Thin films appeared to be pinhole-free with a high crystallinity of a single perovskite phase and a microstructure that showed suitability for oxygen permeation applications. Correlations between thin film properties and MS process parameters (e.g. power, Ar/O2 ratio, pressure, etc.) and TA&/SLA parameters were established and optimised as key factors for producing thin film membrane exhibiting high oxygen flux and good stability. A variation of the oxygen flux through the BSCF asymmetric membrane as well as the porous substrate is presented as a function of temperature and also oxygen partial pressures applied to both sides of the membrane allowing for calculation of permeability of the deposited thin film. Figure 1
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Wu, Liansheng, Haodong Jiang, Tao Luo, and Xinlong Wang. "On the Ionic Conductivity of Cation Exchange Membranes in Mixed Sulfates Using the Two-Phase Model." Membranes 13, no. 10 (September 26, 2023): 811. http://dx.doi.org/10.3390/membranes13100811.
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The concentration dependence of the conductivity of ion exchange membranes (IEMs), as well as other transport properties, has been well explained by the contemporary two-phase model (Zabolotsky et al., 1993) considering a gel phase and an inter-gel phase filled with electroneutral solution. Here, this two-phase model has been adopted and first applied in electrolytes containing mixed counter-ions to investigate the correlation between the membrane ionic conductivity and its microstructure. For three representative commercial cation exchange membranes (CEMs), the total membrane conductivity (κT) when in equilibrium with mixed MgSO4 + Na2SO4 and H2SO4 + Na2SO4 electrolytes could be well predicted with the experimental composition of counter-ions in the gel and inter-gel phase, as well as the counter-ion mobility in the gel phase when the membrane is in a single electrolyte. It is found that the volume fraction of the inter-gel phase (f2) has little impact on the predicted results. The accuracy of the model can be largely improved by calculating the inter-gel phase conductivity (κin) with the ionic mobility being the same as that in the external solution (obtained via simulation in the OLI Studio), rather than simply as equivalent to the conductivity of the external solution (κs). Moreover, a nonlinear correlation between the CEMs’ conductivities and the counter-ion composition in the gel phase is observed in the mixed MgSO4 + Na2SO4 solution, as well as for the Nafion117 membrane in the presence of sulfuric acid. For CEMs in mixed MgSO4 + Na2SO4 electrolytes, the calculated conductivity values considering the interaction parameter σ, similar to the Kohlrausch’s law, are closer to the experimental ones. Overall, this work provides new insights into membrane conductivity with mixed counter-ions and testifies to the applicability of the contemporary two-phase model.
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Whiting, Rose, Pangaea W. Finn, Andrew Bogard, Fulton McKinney, Dallin Pankratz, Aviana R. Smith, Elen A. Gardner, and Daniel Fologea. "Experimental Investigations on the Conductance of Lipid Membranes under Differential Hydrostatic Pressure." Membranes 12, no. 5 (April 29, 2022): 479. http://dx.doi.org/10.3390/membranes12050479.
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The unassisted transport of inorganic ions through lipid membranes has become increasingly relevant to an expansive range of biological phenomena. Recent simulations indicate a strong influence of a lipid membrane’s curvature on its permeability, which may be part of the overall cell sensitivity to mechanical stimulation. However, most ionic permeability experiments employ a flat, uncurved lipid membrane, which disregards the physiological relevance of curvature on such investigations. To fill this gap in our knowledge, we adapted a traditional experimental system consisting of a planar lipid membrane, which we exposed to a controlled, differential hydrostatic pressure. Our electrophysiology experiments indicate a strong correlation between the changes in membrane geometry elicited by the application of pressure, as inferred from capacitance measurements, and the resulting conductance. Our experiments also confirmed the well-established influence of cholesterol addition to lipid membranes in adjusting their mechanical properties and overall permeability. Therefore, the proposed experimental system may prove useful for a better understanding of the intricate connections between membrane mechanics and adjustments of cellular functionalities upon mechanical stimulation, as well as for confirmation of predictions made by simulations and theoretical modeling.
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Sellam, Amine, E. Giglioli, G. Rousse, Y. Klein, F. Porcher, Y. Le Godec, M. Mezouar, et al. "Stabilization of Superconductivity in Pure and C-Intercalated 1T-TaS2 Synthesised Under High Pressure." Advances in Science and Technology 75 (October 2010): 173–80. http://dx.doi.org/10.4028/www.scientific.net/ast.75.173.
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In order to elucidate the origin of the interplay between charge density wave (CDW) and superconductivity in 1T-TaS2, we have synthesized powder samples of pure and C-intercalated 1T-CxTaS2 by means of a multi-anvil high-pressure synthesis method. We have found that single-phase samples are obtained in the 2-6 GPa range at 400 °C and for x=0-0.3. The structural, magnetic and transport properties of all samples have been investigated by means of neutron and x-ray diffraction, dc magnetization and dc electrical resistivity. For all x values including x=0, the data show that the CDW phase is suppressed concomitant to an abrupt onset of superconductivity, with Tc=3.2 K for x=0. The Tc value turns out to be weakly dependent on x, with a maximum Tc=3.8 K for x=0.2. This onset is accompanied by a crossover of magnetic behavior from paramagnetic Pauli-like to paramagnetic Curie-Weiss-like with effective moment 1.2 B/Ta, which suggests that a ionic picture is suitable for the superconducting phase, but not for the CDW phase. The analysis of the dependence of the a and c lattice parameters upon x as well as upon the synthesis conditions shows that the onset of superconductivity is mainly ascribed to unusual changes of the unit cell induced by the high-pressure synthesis. Specifically, the ex-situ lattice parameters exhibit a significantly larger c-axis parameter and a shrinking of the a-axis parameter stabilized by the high-pressure synthesis route. We argue that the above suppression of the CDW phase is induced by a broadening of the relevant 5d(t2g) band which stabilizes the metallic and superconducting phases. This scenario suggests that the strength of the electronic correlations are the main control parameter of the CDW-superconductivity competition in 1T-TaS2.
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Vargas Ordaz, Mariana, Claudio Gerbaldi, Miran Gaberscek, and Robert Dominko. "(Invited) Functional Protective Coatings Based on Polysaccharides and Single-Ion Conducting Polymers for Li Metal Batteries." ECS Meeting Abstracts MA2023-02, no. 6 (December 22, 2023): 922. http://dx.doi.org/10.1149/ma2023-026922mtgabs.
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Li metal batteries are regarded as a promising system to overcome the energy density limitations of the current graphite anode Li-ion batteries, by taking advantage of the low reduction potential of lithium metal (-3.04 V vs SHE) and extremely high theoretical capacity (3860 mAh g-1). However, its use is still plagued with challenges that must be solved in order to achieve a successful Li-metal battery operation, that primarily relies on the performance, stability, and reversibility of the anodic side. Those challenges are related to safety concerns, mainly caused by the uncontrolled growth of high surface area lithium (HSAL) and high volumetric expansion. In this sense, to enable the safe use of Li metal, the concept of protective coating has been proposed, enabling to tailor of adequate interphases that can thermodynamically stabilize the lithium metal surface, and therefore improve the lifespan and safety of the battery. The ideal coating should possess a balance between mechanical strength, flexibility, and ionic conductivity, at the time it enables a uniform and efficient transport of lithium ions. Additionally, it must be electronically insulating and possess high chemical and electrochemically stability. In this context, polymeric coatings can offer good flexibility and elasticity which makes them suitable to adapt to the volumetric changes during lithium stripping/deposition cycles. Moreover, they can form uniform films, creating an ideal contact with lithium metal surface. An attractive group of materials that can provide numerous advantages such as high chemical, mechanical and thermal stability, are polysaccharides, aside from being the highly abundant and renewable resource on the Earth, which can be obtained in different forms. Several studies have shown that concentration polarization during battery operation is the main responsible for HSAL generation and limited cycle life, due to the coupled anion-cation movement in the electrolyte. To solve this problem the use of single-ion conducting polymers (SICPs) can result beneficial due to their immobilized anions to a polymeric backbone, which eases lithium ion transport, boosting lithium transference number (𝑡𝐿𝑖+). In addition, the selection of an appropriate polymeric backbone that can withstand volumetric changes, and allow a satisfactory ionic conductivity is essential. In this regard, the use of cellulose is preferred due to their film formation and mechanical properties, lightweight, high abundance, and biodegradability. Herein, a polymeric coating based on cellulose and P(LiMTFSI) single-ion conductor polymer is studied as a protective coating for metallic Li, in order to prevent HSAL initiation and propagation, as well as to enhance electrochemical stability in liquid and solid polymer electrolyte. The coating effectiveness is tested by casting the solution on activated lithium surface and performing lithium stripping/deposition in Li/Cu pouch cells. Additionally, the correlation with its electrochemical and physicochemical properties is performance based on microscopy and spectroscopy technics, to study the most relevant parameters influencing Coulombic Efficiency.
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Basu, Swastik, and Gyeong S. Hwang. "Uncovering Unique Interfacial Properties in Different Lithium Fluoride Phases: A First-Principles Prediction." ECS Meeting Abstracts MA2022-01, no. 2 (July 7, 2022): 446. http://dx.doi.org/10.1149/ma2022-012446mtgabs.
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Electrolytes are susceptible to reductive decomposition on the surface of negative electrodes leading to the formation and growth of solid-electrolyte interphase (SEI) layer [1]. Stable SEI can be beneficial as a protective layer, given that it can provide insulation to electron transport from the anode to electrolyte, prevent solvent molecules from reaching the anode, and at the same time allow transport of Li+ [2]. Thus, the SEI can contribute critically to the safety and operability of lithium-ion batteries (LIBs), but its functionality heavily depends on the conditions under which it gets synthesized [3]. This can have a significant effect on battery performance. For instance, nucleation and growth of lithium dendrites during cycling is known to result in continuous electrolyte degradation, destruction of the SEI, agglomeration of so-called “dead lithium”, and short-circuiting of the battery [4]. This greatly affects next-generation electric vehicles (EVs), for which all-solid-state lithium-metal batteries (ASSLMBs) have garnered significant attention due to their superior energy storage capacity and safety over LIBs [5]. However, the considerable interfacial impedance originating from poor physical contact and/or parasitic reactions at the Li/SSE interface hinders the development of ASSLMBs. Alternative approaches towards achieving a stable protective interface have been pursued: like use of electrolyte additives to manipulate the constituents and compositions of SEI or designing artificial protective layers to improve performance. For instance, admixture of optimum amounts of fluorine-rich additives like fluoroethylene carbonate (FEC) to traditional carbonate electrolytes (like EC/DMC) has been seen to generate a robust LiF-rich SEI. However, the intrinsic role of LiF remains a topic of uncertainty. Conventional understanding would posit that dominance of LiF leaves the SEI susceptible to poor lithium-ion transport properties. Previously, theoretical works reported significantly lower ionic conductivities in crystalline LiF when compared to other common inorganic SEI materials like Li2O and Li2CO3. Underwhelming transport properties pose serious rate limitations in its effectiveness as a serious candidate for interfacial protection in ASSLMBs. To potentially overcome such bottleneck, this study systematically investigates different phases of LiF: their structures, stabilities and interfacial properties are described using first principles calculations. Careful analysis of the structural models reveals that unlike the widely studied rock salt ordered counterpart, certain phases of LiF exhibit excellent Li+ transport properties with a high predicted diffusivity at room temperature. Mechanically too, improved interfacial qualities are demonstrated with increased flexibility and fracture resistance, opening up important avenues for structural and compositional stability over cell cycling while maintaining its desirable electron-blocking characteristics. However, it is also important to take a step back and note that the rock salt phase is the most energetically stable among LiF phases, which thereby exhibit a propensity for phase transformation under ambient conditions. To overcome this, a strategy of incorporating hetero dopants as impurities to stabilize the host matrix is discussed. By increasing the dopant concentration up to an optimum amount, relative thermodynamic stability of the interface-friendly phases of LiF is achieved. Our examination of the structure reveals unique lithium-dopant interactions which help sustain such LiF phases in the host matrix. The combination of excellent Li-ion transport properties and electron blocking ability makes such LiF-rich composites an excellent candidate for use as an interfacial protective layer that can effectively suppress electrolyte decomposition and Li dendrite propagation, while simultaneously improving the contact and compatibility of the electrode/electrolyte interface. These unique and exceptional traits make them materials of great promise for protecting critical interfaces in ASSLMBs and LIBs. [1] M. Gauthier, T.J. Carney, A. Grimaud, L. Giordano, N. Pour, H.-H. Chang, D.P. Fenning, S.F. Lux, O. Paschos, C. Bauer, F. Maglia, S. Lupart, P. Lamp, Y. Shao-Horn, Electrode−Electrolyte Interface in Li-Ion Batteries: Current Understanding and New Insights, J. Phys. Chem. Lett. 6 (2015) 4653−4672. https://doi.org/10.1021/acs.jpclett.5b01727 [2] D. Bedrov, O. Borodin, J.B. Hooper, Li+ Transport and Mechanical Properties of Model Solid Electrolyte Interphases (SEI): Insight from Atomistic Molecular Dynamics Simulations, J. Phys. Chem. C 121 (2017) 16098–16109. https://doi.org/10.1021/acs.jpcc.7b04247 [3] D. Aurbach, B. Markovsky, I. Weissman, E. Levi, Y. Ein-Eli, On the Correlation Between Surface Chemistry and Performance of Graphite Negative Electrodes for Li Ion Batteries, Electrochim. Acta 45 (1999) 67−86. https://doi.org/10.1016/S0013-4686(99)00194-2 [4] W. Xu, J. Wang, F. Ding, X. Chen, E. Nasybulin, Y. Zhang, J.G. Zhang, Lithium Metal Anodes for Rechargeable Batteries, Energy Environ. Sci. 7 (2014) 513−537. https://doi.org/10.1039/C3EE40795K [5] J. G. Kim, B. Son, S. Mukherjee, N. Schuppert, A. Bates, O. Kwon, M. J. Choi, H. Y. Chung, S. Park, A review of lithium and non-lithium based solid state batteries, J. Power Sources 282 (2015) 299−322. https://doi.org/10.1016/j.jpowsour.2015.02.054
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Garcia‐Mendez, Regina, Jeffrey G. Smith, Joerg C. Neuefeind, Donald J. Siegel, and Jeff Sakamoto. "Correlating Macro and Atomic Structure with Elastic Properties and Ionic Transport of Glassy Li 2 S‐P 2 S 5 (LPS) Solid Electrolyte for Solid‐State Li Metal Batteries." Advanced Energy Materials 10, no. 19 (April 2020): 2000335. http://dx.doi.org/10.1002/aenm.202000335.
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Shock, Everett L., and Harold C. Helgeson. "Calculation of the thermodynamic and transport properties of aqueous species at high pressures and temperatures: Correlation algorithms for ionic species and equation of state predictions to 5 kb and 1000°C." Geochimica et Cosmochimica Acta 52, no. 8 (August 1988): 2009–36. http://dx.doi.org/10.1016/0016-7037(88)90181-0.
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Ruano, Guillem, José I. Iribarren, Maria M. Pérez-Madrigal, Juan Torras, and Carlos Alemán. "Electrical and Capacitive Response of Hydrogel Solid-Like Electrolytes for Supercapacitors." Polymers 13, no. 8 (April 19, 2021): 1337. http://dx.doi.org/10.3390/polym13081337.
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Flexible hydrogels are attracting significant interest as solid-like electrolytes for energy storage devices, especially for supercapacitors, because of their lightweight and anti-deformation features. Here, we present a comparative study of four ionic conductive hydrogels derived from biopolymers and doped with 0.1 M NaCl. More specifically, such hydrogels are constituted by κ-carrageenan (κC), carboxymethyl cellulose (CMC), poly-γ-glutamic acid (PGGA) or a phenylalanine-containing polyesteramide (PEA). After examining the morphology and the swelling ratio of the four hydrogels, which varies between 483% and 2356%, their electrical and capacitive behaviors were examined using electrochemical impedance spectroscopy. Measurements were conducted on devices where a hydrogel film was sandwiched between two identical poly(3,4-ethylenedioxythiophene) electrodes. The bulk conductivity of the prepared doped hydrogels is 76, 48, 36 and 34 mS/cm for PEA, PGGA, κC and CMC, respectively. Overall, the polyesteramide hydrogel exhibits the most adequate properties (i.e., low electrical resistance and high capacitance) to be used as semi-solid electrolyte for supercapacitors, which has been attributed to its distinctive structure based on the homogeneous and abundant distribution of both micro- and nanopores. Indeed, the morphology of the polyestermide hydrogel reduces the hydrogel resistance, enhances the transport of ions, and results in a better interfacial contact between the electrodes and solid electrolyte. The correlation between the supercapacitor performance and the hydrogel porous morphology is presented as an important design feature for the next generation of light and flexible energy storage devices for wearable electronics.
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Snyder, Joshua David. "Molecular Additives at the Catalyst Ionomer Interface." ECS Meeting Abstracts MA2023-02, no. 40 (December 22, 2023): 1979. http://dx.doi.org/10.1149/ma2023-02401979mtgabs.
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The growth and viability of deep decarbonization through the hydrogen economy is dependent upon scientific advances that will address the existing political, regulatory, and technological barriers that currently hinder electrochemical energy technologies. The strong correlation between device-level performance and catalytic electrode activity/durability highlights the criticality of identifying the limiting processes and developing strategies to address these limitations. The goal of our group is to use fundamental insight derived from the study of well-defined systems to develop unique mitigation strategies, aimed at improving device-level performance, that go beyond simply varying electrocatalyst material properties. The interface between catalyst and ionomer in polymer electrolyte membrane fuel cells (PEMFC) greatly limits device performance through detrimental impacts to local reactant transport and reaction kinetics. Optimization of the catalyst/ionomer interface to not only mitigate these detrimental impacts, but to also beyond existing performance is a challenging task. In this presentation we will present our work in developing molecular interfacial modifying species to optimize the interaction between catalyst and ionomer. Integrating molecular components such as ionic liquids or caffeine both enhances the kinetics of the electrode reactions and limits the detrimental impacts of ionomer on the catalyst surface. We will present our fundamental understanding of why these molecular additives improve catalyst activity and limit the impacts of ionomer. We will also present our integration of these molecular moieties into next generation ionomers and their performance in PEMFC membrane electrode assemblies (MEA).
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Dorzhieva, S. G., and J. G. Bazarova. "Synthesis, thermal and dielectric characteristics of Rb<sub>5</sub>Li<sub>1/3</sub>Zr<sub>5/3</sub>(MoO<sub>4</sub>)<sub>6</sub>." Proceedings of Universities. Applied Chemistry and Biotechnology 12, no. 4 (January 1, 2023): 514–20. http://dx.doi.org/10.21285/2227-2925-2022-12-4-514-520.
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This work addressed the directed synthesis of a new phase Rb5Li1/3Zr5/3(MoO4)6, along with the determination of its crystallographic, thermal and electrophysical properties. The directed synthesis of the Rb5Li1/3Zr5/3(MoO4)6 phase was carried out using the solid-state reaction in the temperature range of 350–470 °C. According to differential scanning calorimetry, the synthesised compound Rb5Li1/3Zr5/3(MoO4)6, crystallised in trigonal form (space group R3c, Z = 6), undergoes a diffused first-order phase transition. The structure of triple molybdate Rb5Li1/3Zr5/3(MoO4)6 comprises MoO4 tetrahedra and octahedrally coordinated MO6-polyhedra. This structure is characterised by a statistical distribution of lithium and zirconium atoms in the M position (M1 = 0.790 Zr + 0.210 Li, M2 = 0.877 Zr + 0.123 Li). Rb atoms are located in the large voids of the tetrahedronoctahedral framework. The electrophysical properties of triple molybdate Rb5Li1/3Zr5/3(MoO4)6 having a scaffold structure favourable for ion transport, were studied. The correlation between dielectric and thermal characteristics in the high-temperature region near the phase transition was revealed. The temperature and frequency dependences of electrical conductivity were measured at 473–873 K in heating and cooling modes in the frequency range of 1–10 kHz. The compound exhibited a high thermally activated conductivity, reaching 1.48·10-2 Cm K/cm with activation energy in the range of 0.6–0.8 eV at a temperature of 480 °C. Well-shaped semicircles in the low-frequency region and unresolved arcs in the high-frequency region changing with increasing temperature were observed in the impedance spectra of ceramic Rb5Li1/3Zr5/3(MoO4)6 sample at various temperatures. The evolution of the imaginary part (Z'') as a function of the real part (Z') of the complex impedance resembled that of the complex impedance for compounds having ionic conductivity.
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Morozova, Polina A., Stanislav S. Fedotov, and Artem M. Abakumov. "(Digital Presentation) Prussian Blue Analogs – a Wide Variety of Promising Cathode Materials with Peculiar Electrochemical Properties." ECS Meeting Abstracts MA2022-01, no. 1 (July 7, 2022): 59. http://dx.doi.org/10.1149/ma2022-01159mtgabs.
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Today, post-lithium energy storage technologies are now rapidly progressing due to the high price of a net Li-ion battery, which also depends on the desired capacity and power. Among sodium, potassium, calcium, magnesium, and even aluminum-based alternatives, young potassium-ion batteries demonstrate high capacity and energy density, notable ionic transport in electrolytes, the possibility to employ graphite anodes, and a wide variety of possible electrode materials: layered oxides, polyanionic, organic compounds, Prussian Blue analogs. However, the latter ones are generally considered as the most promising and practically viable. Prussian Blue analogs form a big family of electrode materials with the general formula KxM1[M2(CN)6]∙nH2O, where x=0...2, and Mi are any possible 3d transition metals. The most well-known and commercially available is based on a hexacyanoferrate anion [Fe(CN)6]n-, while other transition metals can also form hexacyanometallate complexes, but are poorly studied or not known at all. The most part of published works shed light on the morphology and low content of water defects inside crystallites counting the lack of hexacyanoferrate, and their influence on realized capacity and capacity fades, while the fundamental principles and real water position presence which guide the electrochemical activity of high- and low-spin cations in these materials are totally missed. In our work, we also started with the intrinsic water defects and their impact on crystal and physicochemical properties in K2Mn[Fe(CN)6]∙nH2O but with sensitive to light atoms neutron diffraction technique. We observed that water content does not effect the whole crystal symmetry but slightly amend unit cell parameters. Besides the fact of decreasing a decomposition temperature in “watered” Prussian Blue analog, electrochemical properties were found close. Therefore, we concluded that intrinsic water does not notably influence material properties. Continuing with potassium manganese hexacyanoferrate and electronic structure impact to the compound properties, to reveal the best synergetic stabilizing agent during cycling, we synthesized and studied the system K2-γMn1-xCox[Fe(CN)6]∙nH2O with x=0, 0.05,...1. In addition to symmetry and composition transformations, magnetic and electrochemical properties also significantly differ, while higher cobalt content increases the redox potential of iron, but drastically decreases total capacity due to the inability of reaching iron oxidation. The fact of notable changing of redox potentials in K2-γMn1-xCox[Fe(CN)6]∙nH2O is inspiring, and we have been extending with other hexacyanometallates. Hexacyanomanganate-ion [Mn(CN)6]n- is one of the promising pathways to investigate such systems with a more fundamental point of view, and the obtained experimental results confirm the hypothesis. We discovered that cation position exchange totally alters the electrochemistry of the Prussian Blue cathode materials, and the interpretation still raises a lot of questions and assumptions, and together with computational chemistry, we will try to answer the fundamental questions about electronic, crystal structures and electrochemical properties. In this report we will present the new correlations of redox potential in Prussian Blue analogs depending on transition metal position and electronic structure, evaluate diffusion of potassium in these materials, and try to answer the possibility to use these compounds in potassium-ion batteries.
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ANWAR, M., S. A. SIDDIQI, and I. M. GHAURI. "AC CONDUCTION IN MIXED OXIDES Al–In2O3–SnO2–Al STRUCTURE DEPOSITED BY CO-EVAPORATION." Surface Review and Letters 13, no. 04 (August 2006): 457–69. http://dx.doi.org/10.1142/s0218625x06008438.
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Conductivity-frequency and capacitance-frequency characteristics of mixed oxides Al – In 2 O 3– SnO 2– Al structure are examined to elicit any correlation with the conduction mechanisms most often observed in thin film work. The existence of Schottky barriers is believed to be due to a strong donor band in the insulator established during the vacuum evaporation when a layer of mixed oxides In 2 O 3– SnO 2 system is sandwiched between two metal electrodes. Low values of activation energy at low temperatures indicate that the transport of the carriers between localized states is mainly due to electronic hopping over the barrier separating the two nearest neighbor sites. The increase in the formation of ionized donors with increase in temperature during electrical measurements indicates that electronic part of the conductivity is higher than the ionic part. The initial increase in conductivity with increase in Sn content in In 2 O 3 lattice is caused by the Sn atom substitution of In atom, giving out one extra electron. The decrease in electrical conductivity above the critical Sn content (10 mol% SnO 2) is caused by the defects formed by Sn atoms, which act as carrier traps rather than electron donors. The increase in electrical conductivity with film thickness is caused by the increase in free carriers density, which is generated by oxygen vacancy acting as two electron donor. The increase in conductivity with substrate and annealing temperatures is due to either the severe deficiency of oxygen, which deteriorates the film properties and reduces the mobility of the carriers or to the diffusion of Sn atoms from interstitial locations into the In cation sites and formation of indium species of lower oxidation state ( In 2+). Calculations of C and σac from tan δ measurements suggest that there is some kind of space-charge polarization in the material, caused by the storage of carriers at the electrodes. Capacitance decreases not only with the rise of frequency but also with the lowering of temperature. At low temperatures the major contribution to capacitance arises from the ionic polarization, however, with the increase of temperature the contribution from orientation polarization would considerably increase. The decrease in capacitance with the increase in frequency may be attributed to interfacial polarization.
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Kwon, Eunji, Hyun-kyu Lim, and Sangheon Lee. "Atomistic Scale Analysis of Motion and Dynamics of Li-Ion in Li-Zn-Zr-S Compound Electrolyte." ECS Meeting Abstracts MA2022-01, no. 55 (July 7, 2022): 2272. http://dx.doi.org/10.1149/ma2022-01552272mtgabs.
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Solid-state electrolytes are considered as key materials for overcoming the limitations of the liquid-electrolyte-based Li-ion batteries in terms of energy capacity, cyclability, and safety. Among the many possible solid-state electrolyte materials, inorganic sulfides are of intensive research interest mainly because the larger and more polarizable sulfur anions substantially enhance the mobility of cationic Li species. In particular, Li-P-S electrolytes, such as Li10GeP2S12and Li7P3S11, have been reported to have room-temperature Li-ion conductivity of greater than 10-2 S/cm, which is comparable to that of conventional liquid electrolytes. Despite the facile Li-ion transport, the Li-P-S electrolytes tend to undergo irreversible structural degradation within typical operating conditions of the battery. This lack of electrochemical stability leads to the formation of high impedance intermediate transition layers at the electrode/electrolyte interfaces, hindering the practical application of the Li-P-S electrolytes. Partial replacement of the element P with other elements within a Li-P-S structural family can improve the lithium-ion conductivity, but notable improvement in their electrochemical stability has yet to be achieved. Li-M-S (M = transition metals, such as Cr, Zr, Nb, Mo, and Sn) families can be possible candidates for electrochemically stabile solid-state electrolytes, while having excellent Li-ion transport properties of the inorganic sulfides. Like the Li-P-S structure, numerous Li-M-S structural derivatives have already been synthesized by varying the element M or by replacing a portion of the element M with another element, and the Li-ion conductivity and electrochemical stability are expected to be heavily dependent on the element composition and crystalline structure. In this study, we investigate the motion and dynamics of Li-ions in Li-Zr-S and Li-Zn-Zr-S compound electrolyte by performing a series of first-principles calculations. To this end, we generate multiple Li-Zn-Zr-S compound model structures with varying Zr-to-Zn ratios. Then, we evaluate Li-ion conductivities by using velocity auto correlation scheme combined ab initio molecular dynamics (AIMD) simulations. More specifically, we calculate the diffusivity and ionic conductivity of the stoichiometric structure and at a range of defect concentrations on Li2+2xZnxZr1-xS3, from x = 0 to x = 0.5. Our calculation results reveal how the introduction of Zn into the Li-Zr-S compound affects the Li-ion mobilities. The theoretical insight obtained in this study well corroborates with recently reported experimental results for varying ionic conductivities in Li-Zn-Zr-S electrolytes depending on the Zr-to-Zn ratio. This fundamental understanding can be an important theoretical basis for developing practically applicable Li-M-S electrolytes. Figure 1
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Ando, Uta, Takuya Okada, Mitsuhiro Matsumoto, Yohtaro Inoue, Katsumi Katakura, Katsuhiko Tsunashima, and Hirohisa Yamada. "(Digital Presentation) ORR Activities on Hydrophobic Phosphonium Ionic Liquid Modified Pt/C Catalysts." ECS Meeting Abstracts MA2022-02, no. 64 (October 9, 2022): 2377. http://dx.doi.org/10.1149/ma2022-02642377mtgabs.
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PEFCs have been attracted as one of the clean and efficient energy conversion systems. Platinum nanoparticles are commonly used as cathode catalysts in Polymer electrolyte fuel cells (PEFCs) due to their high activity for oxygen reduction reaction (ORR). However, platinum is rare and expensive, therefore it needs to improve the mass activity and durability for widespread fuel cells. Recently, ionic liquids (ILs) have been studied to enhance the ORR activity of platinum catalysts1). We try to improve the catalytic activity of Pt/C catalysts by using Ionic Liquids (ILs). RTILs are salts that melt at temperatures below 100 oC and generally consist of bulky cations and anions. It has been studied in a wide range of fields, including the energy sector because of its highly conductive and nonvolatile. Recently, it has been reported that ILs layer enhance the ORR catalytic activity on Pt surface, due to the suppress the coverage of OHad from water molecules1). However, the correlation between increased ORR activity and the structure of the ionic liquid has not been clarified. In this study, we focused on ILs quaternary phosphonium cations and a bis(trifluoromethylsulfonyl)amide (TFSA) anion. The phosphonium cations based ILs have been reported to have higher thermal stability than imidazolium or ammonium cations2). In addition, the phosphonium ILs show higher electrochemical stability, conductivity, and hydrophobicity than the ammonium ILs. The ORR activity was analyzed using the rotating disk electrode (RDE) method3). Commercially available 20 wt% Pt/C (Cabot, Vulcan XC-72R🄬) catalyst was used for bare Pt/C modified electrodes. The Pt/C electrodes were modified with phosphonium ILs (PXXXY+TFSA- [alkyl chain X= 4 Y= 1, 12, 16]). The thickness of the ILs layer was calculated by using the BET surface area of carbon supports. The electrochemical measurements were conducted under Ar or O2 saturated conditions, respectively. Electrochemical surface area (ECSA) was estimated from hydrogen adsorption wave in cyclic voltammograms (CVs). Mass activity (MA) and surface area specific activity (SA) of ORR at 0.9 V on Pt nanoparticles were calculated from the Koutecky-Levich equation. The ILs layer enhanced ORR activity. However, ORR activity decreased when the ILs layer was excessively thick. These results suggest that the ORR activity decreases in a thicker ILs layer due to increased resistance to oxygen mass transport or proton conductivity. Moreover, the ORR activity of the ILs modified Pt/C catalyst increased as the asymmetric part alkyl chains of the ILs became longer. Our previous reports show that as the size -is larger, both the molar volume and oxygen solubility increases. Our results show that these physicochemical properties originating from the structure of the cation affect ORR activities. [Reference] 1) Gui-Rong Zhang, et al., ACS Catal., 8, 8244-8254 (2018). 2) K. Tsunashima and M. Sugiya, Electrochem. Commun., 9, 2353, (2007). 3) H. A. Gasteiger, S. S. Kocha, B. Sompalli, F. T. Wagner, Appl. Catal. B Environ. 56, 9. (2005).
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Song, Yueming, Bhuvsmita Bhargava, Zoey Warecki, David Murdock Stewart, and Paul Albertus. "Multi-Scale Electrochemo-Mechanical Experiments on Thin Film Battery Materials." ECS Meeting Abstracts MA2022-02, no. 47 (October 9, 2022): 1760. http://dx.doi.org/10.1149/ma2022-02471760mtgabs.
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The application of a solid-electrolyte may enable the use of certain high energy density anodes like Li and Si and also circumvents the flammable liquid-electrolyte. However, all solid components introduce multiple solid-solid interfaces whose responses are strongly affected by the mechanical state of the region on both sides, which can be affected by a combination of applied stack pressure and cycling induced volumetric change1. Electrochemo-mechanical coupling (ECM) studies2 are a relatively new area for this society, especially with thin film structures,3 which provide high purity, uniformity, and controlled geometries for the reaction to take place. However, correctly interpreting ECM experimental results as well as explaining the fundamental failure mechanisms (i.e. cracking and dendrite propagation) requires careful experimental study of material mechanical properties and how electrochemical characteristics change with mechanical state4. In this work, we describe two experimental studies on sputter-deposited thin-film LixV2O5 electrodes, with a thickness of 1 µm on a Si wafer. A lateral cell design that has the two electrodes on a single plane on a substrate, is described to focus on a single electrode. An ionic liquid electrolyte (ILE) on the Si substrate is used instead of a solid electrolyte pellet to avoid high ohmic losses , and to focus on the mechanics of the LixV2O5. The ILE covers the two electrodes and serves as the ionic pathway. Lithium foil (or vapor-deposited Li metal) is placed on the wafer and serves as the Li source. The first study is conducted with a liquid electrolyte and compares the cell behaviors between stressed and unstressed states. An external mechanical load is applied to the whole electrode surface for a uniform force distribution. An important thermodynamic contribution of stress is the change in equilibrium potential, which can be measured as a function of applied stress on the electrode and may also affect charge transfer kinetics at the interface. The second experiment will focus on the composition modulated mechanical properties of LixV2O5 which is crucial for ECM modeling work. Here, we lithiate V2O5 electrodes to different amounts, remove the electrolyte to stop ionic transport, and then perform nanoindentation in an inert argon environment. The correlation between elastic moduli and x in LixV2O5 as well as the variation of equilibrium potential provide important parameters for building accurate ECM numerical models. Pasta, M., Armstrong, D., Brown, Z.L., Bu, J., Castell, M.R., Chen, P., Cocks, A., Corr, S.A., Cussen, E.J., Darnbrough, E., et al. (2020). 2020 roadmap on solid-state batteries. JPhys Energy 2, 032008. Wan, T.H., and Ciucci, F. (2020). Electro-chemo-mechanical modeling of solid-state batteries. Electrochim. Acta 331, 135355. Spencer Jolly, D., Ning, Z., Darnbrough, J.E., Kasemchainan, J., Hartley, G.O., Adamson, P., Armstrong, D.E.J., Marrow, J., and Bruce, P.G. (2020). Sodium/Na β″ Alumina Interface: Effect of Pressure on Voids. ACS Appl. Mater. Interfaces 12, 678–685. Cao, D., Sun, X., Li, Q., Natan, A., Xiang, P., and Zhu, H. (2020). Lithium Dendrite in All-Solid-State Batteries: Growth Mechanisms, Suppression Strategies, and Characterizations. Matter 3, 57–94.