Articles de revues : « Silicon cycle »

1

Ittekkot, Venugopalan, Lars Rahm, Dennis P. Swaney et Christoph Humborg. « Perturbed silicon cycle discussed ». Eos, Transactions American Geophysical Union 81, n^o 18 (2000) : 198. http://dx.doi.org/10.1029/00eo00135.

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Wang, Jing, Xiao Hang Yang, Yue Feng Su, Shi Chen et Feng Wu. « Effect of Fluorine-Containing Additive on the Electrochemical Properties of Silicon Anode for Lithium-Ion Batteries ». Materials Science Forum 944 (janvier 2019) : 699–704. http://dx.doi.org/10.4028/www.scientific.net/msf.944.699.

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Silicon anode is a promising candidate as an alternative to the conventional graphitic anode in lithium-ion batteries. In this work, silicon anode is modified by NH4F using a facile method in air. The concentration of NH4F on the electrochemical performance is systematically checked. The 5wt%NH4F-modified silicon anode exhibits enhanced cycle and rate performances, the first discharge specific capacity is 3958 mAh·g-1 with 86.45% as the coulombic efficiency at 0.4A·g-1. The capacity can maintain at 703.3 mAh·g-1 after 50 cycles, exhibiting a much better cycle stability than pristine silicon anode (329.9 mAh·g-1 after 50 cycles). SEM images confirm that NH4F can alleviate the volume expansion of silicon since LiF can be generated at the surface which is beneficial to the stability of solid-electrolyte interphase (SEI).

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Struyf, Eric, Adriaan Smis, Stefan Van Damme, Patrick Meire et Daniel J. Conley. « The Global Biogeochemical Silicon Cycle ». Silicon 1, n^o 4 (octobre 2009) : 207–13. http://dx.doi.org/10.1007/s12633-010-9035-x.

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Ikeda, Takeshi. « Bacterial biosilicification : a new insight into the global silicon cycle ». Bioscience, Biotechnology, and Biochemistry 85, n^o 6 (20 avril 2021) : 1324–31. http://dx.doi.org/10.1093/bbb/zbab069.

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ABSTRACT Biosilicification is the process by which organisms incorporate soluble, monomeric silicic acid, Si(OH)4, in the form of polymerized insoluble silica, SiO2. Biosilicifying eukaryotes, including diatoms, siliceous sponges, and higher plants, have been the targets of intense research to study the molecular mechanisms underlying biosilicification. By contrast, prokaryotic biosilicification has been less well studied, partly because the biosilicifying capability of well-known bacteria was not recognized until recently. This review summarizes recent findings on bacterial extracellular and intracellular biosilicification, the latter of which has been demonstrated only recently in bacteria. The topics discussed herein include bacterial (and archaeal) extracellular biosilicification in geothermal environments, encapsulation of Bacillus spores within a silica layer, and silicon accumulation in marine cyanobacteria. The possible contribution of bacterial biosilicification to the global silicon cycle is also discussed.

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Koraag, Pierre Yosia Edward, Arief Muhammad Firdaus, Naufal Hanif Hawari, Andam Deatama Refino, Wibke Dempwolf, Ferry Iskandar, Erwin Peiner, Hutomo Suryo Wasisto et Afriyanti Sumboja. « Covalently Bonded Ball-Milled Silicon/CNT Nanocomposite as Lithium-Ion Battery Anode Material ». Batteries 8, n^o 10 (7 octobre 2022) : 165. http://dx.doi.org/10.3390/batteries8100165.

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The demand for high-capacity lithium-ion batteries (LIBs) is ever-increasing. Thus, research has been focused on developing silicon-based anodes due to their high theoretical capacity and natural abundance. However, silicon-based anodes still suffer from several drawbacks (e.g., a huge volume expansion during lithiation/delithiation and the low conductivity nature of silicon). In this study, we develop a facile and low-cost synthesis route to create a composite of silicon particles and carbon nanotubes (CNTs) via simple two-step mechanical ball milling with a silicon wafer as the silicon precursor. This method produces a strong interaction between silicon particles and the CNTs, forming Si–C bonds with minimum oxidation of silicon and pulverization of the CNTs. The resulting Si/CNT anode exhibits a first cycle Coulombic efficiency of 98.06%. It retains 71.28% of its first cycle capacity of 2470 mAh g−1 after 100 cycles of charge–discharge at a current density of 400 mA g−1. Furthermore, the Si/CNT anode also shows a good rate capability by retaining 80.15%, and 94.56% of its first cycle capacity at a current density of 1000 mA g−1 and when the current density is reduced back to 200 mA g−1, respectively.

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Chan, Kwai S., Michael A. Miller, Carol Ellis-Terrell et Candace K. Chan. « Synthesis and Characterization of Empty Silicon Clathrates for Anode Applications in Li-ion Batteries ». MRS Advances 1, n^o 45 (2016) : 3043–48. http://dx.doi.org/10.1557/adv.2016.434.

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ABSTRACTSeveral processing methods were developed and evaluated for synthesizing empty silicon clathrates. A solution synthesis method based on the Hofmann-elimination oxidation reaction was successfully utilized to produce 20 mg of empty Si46. Half-cells using the Si46 electrodes were successfully cycled for 1000 cycles at rate of 5.3C. The capacity of the Si46 electrode in long-term tests was 675 mAh/g at the 4th cycle, but increased to 809 mAh/g at 50 cycles. The corresponding Coulombic efficiency was better than 99%. The capacity dropped from 809 to 553 mAh/g after 1000 cycles while maintaining a 99% Coulombic efficiency. In comparison, a Ba8Al8Si38 electrode could be cycled for about 200 cycles with a lower capacity and Coulombic efficiency. Potential applications of empty silicon clathrates as anode materials in Li-ion batteries are discussed.

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de Tombeur, F., B. L. Turner, E. Laliberté, H. Lambers, G. Mahy, M. P. Faucon, G. Zemunik et J. T. Cornelis. « Plants sustain the terrestrial silicon cycle during ecosystem retrogression ». Science 369, n^o 6508 (3 septembre 2020) : 1245–48. http://dx.doi.org/10.1126/science.abc0393.

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The biogeochemical silicon cycle influences global primary productivity and carbon cycling, yet changes in silicon sources and cycling during long-term development of terrestrial ecosystems remain poorly understood. Here, we show that terrestrial silicon cycling shifts from pedological to biological control during long-term ecosystem development along 2-million-year soil chronosequences in Western Australia. Silicon availability is determined by pedogenic silicon in young soils and recycling of plant-derived silicon in old soils as pedogenic pools become depleted. Unlike concentrations of major nutrients, which decline markedly in strongly weathered soils, foliar silicon concentrations increase continuously as soils age. Our findings show that the retention of silicon by plants during ecosystem retrogression sustains its terrestrial cycling, suggesting important plant benefits associated with this element in nutrient-poor environments.

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Ma, Kai. « Silicon-Based Anode with High Capacity and Performance Produced by Magnesiothermic Coreduction of Silicon Dioxide and Hexachlorobenzene ». Journal of Electrochemical Science and Technology 12, n^o 3 (31 août 2021) : 317–22. http://dx.doi.org/10.33961/jecst.2020.01662.

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Silicon (Si) has been considered as a promising anode material because of its abundant reserves in nature, low lithium ion (Li+) intercalation/de-intercalation potential (below 0.5 V vs. Li/Li+) and high theoretical capacity of 4200 mA h/g. In this paper, we prepared a silicon-based (Si-based) anode material containing a small amount of silicon carbide by using magnesiothermic coreduction of silica and hexachlorobenzene. Because of good conductivity of silicon carbide, the cycle performance of the silicon-based anode materials containing few silicon carbide is greatly improved compared with pure silicon. The raw materials were formulated according to a silicon-carbon molar ratio of 10:0, 10:1, 10:2 and 10:3, and the obtained products were purified and tested for their electrochemical properties. After 1000 cycles, the specific capacities of the materials with silicon-carbon molar ratios of 10:0, 10:1, 10:2 and 10:3 were still up to 412.3 mA h/g, 970.3 mA h/g, 875.0 mA h/g and 788.6 mA h/g, respectively. Although most of the added carbon reacted with silicon to form silicon carbide, because of the good conductivity of silicon carbide, the cycle performance of silicon-based anode materials was significantly better than that of pure silicon.

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Fu, Qiang Wei, et Xun Yong Jiang. « Lithium Storage Property of Metallic Silicon Treated by Mechanical Alloying ». Materials Science Forum 847 (mars 2016) : 29–32. http://dx.doi.org/10.4028/www.scientific.net/msf.847.29.

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Theoretical capacity of silicon is 4200mAhg-1, but pure silicon had huge volume change during lithium insertion, which reduces the cycle life of silicon. In this paper, pure silicon was replaced of metallic silicon to relieve volume effect. Metallic silicon contains some alloying elements which improve the conductivity of the electrode material. The elements in metallic silicon will relief the volume change of silicon substrate during lithium insertion/ de-lithiation process. Metallic silicon was treated by mechanical alloying (MA) which is an effective method to reduce particle sizes of metallic silicon. The results show that MA can improve cycle performance of metallic silicon. Metallic silicon treated by MA performs a better cycling performance compared with the unsettled materials and a higher discharge capacity in the first cycle.

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Sarracino Martínez, O., J. Escorcia-Garcia, J. M. Gracia-Jiménez et V. Agarwal. « Photoluminescent Photonic Devices from Nanostructured Porous Silicon Fabricated Using Lightly Doped Silicon ». Journal of Nano Research 4 (janvier 2009) : 11–17. http://dx.doi.org/10.4028/www.scientific.net/jnanor.4.11.

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In this work, we report the fabrication of porous silicon multilayers using lightly doped, p-type, silicon wafers (resistivity: 14-22 Ω-cm) by pulsed anodic etching. The optical properties have been found to be strongly dependent on the duty-cycle and frequency of the applied current. Less than 50 % of duty-cycle, at low frequencies, is found to show very rough porous silicon – crystalline silicon (PS-cSi) interface. Use of duty cycle above 50 %, in a certain range of frequencies, is found to make the interface smooth. The optical properties of the photonic devices are investigated for 50 % and 75 % of duty-cycle, for different frequencies in the range of 0-1000 Hz, using the current densities of 10, 90 and 150 mA/cm2. The possibility of fabricating rugate filter with this resistivity is also explored.

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Feng, Xuejiao, Hongmin Cui, Zhenming Li, Rongrong Miao et Nanfu Yan. « Scalable Synthesis of Dual-Carbon Enhanced Silicon-Suboxide/Silicon Composite as Anode for Lithium Ion Batteries ». Nano 12, n^o 07 (juillet 2017) : 1750084. http://dx.doi.org/10.1142/s1793292017500849.

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The SiOx/Si composite enhanced by dual-carbon (i.e., multiwall carbon nanotubes and carbon) was fabricated from the micro silicon monoxide (SiO) by the combination of high-energy mechanical milling, spray drying and pyrolysis. The obtained SiOx/Si particles were composed of Si-suboxide and embedded nano-sized Si crystallites. As one of dual-carbons, the multi-walled carbon nanotubes were directly scaffolded of anchoring the SiOx/Si composite particles through spray drying. Another carbon source was directly deposited on the surface of the SiOx/Si by means of the carbonization of phenol–formaldehyde resin. Nano-sized silicon embedded in the Si-suboxide matrix and dual-carbon provided a compromise between the reversible capacity and cycle stability related to the volume change. The obtained SiOx/Si/MWCNT/PC-1 electrode delivered an initial capacity of 936.5[Formula: see text]mAh g[Formula: see text] and the reversible capacity was maintained at 825.9[Formula: see text]mAh g[Formula: see text] with excellent capacity retention of 87.5% on the 200th cycle versus the 6th one (compared with the same current rate). In contrast, although the SiOx/Si presented the higher initial capacity of 1271.4[Formula: see text]mAh g[Formula: see text], its capacity dropped quickly after several cycles and capacity retention was only 25.6% versus the 6th cycle after 100 cycles.

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Haufe, Stefan, Johanna Ranninger, Rebecca Bernhard, Irmgard Buchberger et Eckhard Hanelt. « Improving Cycle Life of Silicon-Dominant Anodes Based on Microscale Silicon Particles under Partial Lithiation ». Batteries 9, n^o 1 (13 janvier 2023) : 58. http://dx.doi.org/10.3390/batteries9010058.

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Using only parts of the maximum capacity of silicon microparticles in a lithium-ion battery (LIB) anode represents a promising material concept. The high capacity, better rate capability compared with graphite and accessibility on an industrial scale, as well as its attractive cost make microsilicon an ideal choice for the next generation anode material. However, currently the cycle life of LIBs using silicon particles in the anode is limited due to drastic volume change of Si during lithiation and delithiation. Continuous formation of a solid electrolyte interphase (SEI) and the associated lithium loss are the main failure mechanisms, while particle decoupling from the conductive network plays a role mainly during operation at low discharge voltages. The present study discusses approaches on the material- and cell-level to enhance cycle performance of partially lithiated silicon microparticle-based full cells by addressing the previously described failure mechanisms. Reducing the surface area of the silicon particles and coating their surface with carbon to improve the electronic contact, as well as prelithiation to compensate for lithium losses have proven to be the most promising approaches. The advantageous combination of these routes resulted in a significant increase in cycling stability exceeding 600 cycles with 80% capacity retention at an initial capacity of about 1000 mAh g−1 at anode level, compared to only about 250 cycles for the non-optimized full cell.

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Kim, Bo Eun, Sang Eun Park, Sang Wha Lee, Jong Choo Lim, Byoung Won Cho et Joong Kee Lee. « Porous TiO₂ Layer Encapsulated Silicon as the Anode Material for Lithium Secondary Batteries ». Materials Science Forum 620-622 (avril 2009) : 29–32. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.29.

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The porous TiO2 layer on the silicon surface not only acts as a buffer layer to relieve the strain associated with the volume expansion but also prevents the aggregation of the particles upon normal cycles of charging and discharging. The control of the optimum amount of catalyst has led to enhance the cycle performance of TiO2 coated silicon anode.

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Shintani, Ryo, Ryo Takano et Kyoko Nozaki. « Rhodium-catalyzed asymmetric synthesis of silicon-stereogenic silicon-bridged arylpyridinones ». Chemical Science 7, n^o 2 (2016) : 1205–11. http://dx.doi.org/10.1039/c5sc03767k.

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Vlad, Alexandru, Arava Leela Mohana Reddy, Anakha Ajayan, Neelam Singh, Jean-François Gohy, Sorin Melinte et Pulickel M. Ajayan. « Roll up nanowire battery from silicon chips ». Proceedings of the National Academy of Sciences 109, n^o 38 (4 septembre 2012) : 15168–73. http://dx.doi.org/10.1073/pnas.1208638109.

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Here we report an approach to roll out Li-ion battery components from silicon chips by a continuous and repeatable etch-infiltrate-peel cycle. Vertically aligned silicon nanowires etched from recycled silicon wafers are captured in a polymer matrix that operates as Li+ gel-electrolyte and electrode separator and peeled off to make multiple battery devices out of a single wafer. Porous, electrically interconnected copper nanoshells are conformally deposited around the silicon nanowires to stabilize the electrodes over extended cycles and provide efficient current collection. Using the above developed process we demonstrate an operational full cell 3.4 V lithium-polymer silicon nanowire (LIPOSIL) battery which is mechanically flexible and scalable to large dimensions.

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Carey, Joanna. « Soil age alters the global silicon cycle ». Science 369, n^o 6508 (3 septembre 2020) : 1161–62. http://dx.doi.org/10.1126/science.abd9425.

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Oliver, John Y., Rajeevan Amirtharajah, Venkatesh Akella, Roland Geyer et Frederic T. Chong. « Life Cycle Aware Computing : Reusing Silicon Technology ». Computer 40, n^o 12 (décembre 2007) : 56–61. http://dx.doi.org/10.1109/mc.2007.433.

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Carroll, Gerard (MIke) Michael, Maxwell Schulze, Fernando Urias, Nikita Dutta, Zoey Huey, Jaclyn Coyle, Glenn Teeter et al. « Control of Nanoparticle Dispersion, SEI Composition, and Electrode Morphology Enable Long Cycle Life in High Silicon Content, Nanoparticle-Based Composite Anodes for Lithium-Ion Batteries ». ECS Meeting Abstracts MA2023-01, n^o 2 (28 août 2023) : 529. http://dx.doi.org/10.1149/ma2023-012529mtgabs.

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Striking a balance between high theoretical capacity, Earth abundance, and compatibility with existing manufacturing infrastructure, silicon is one of the few materials that meets the requirements for a next-generation anode for rechargeable lithium-ion batteries. Due to complications with extreme volume changes during charging/discharging and reactive interfacial chemistries, however, the cycle-life of silicon-based composite anodes is unacceptable for broad use. Developing a majority silicon composite anode formulation that overcomes these challenges and is compatible with current industry manufacturing practices requires materials and chemical engineering solutions that account for both electrode morphology and interfacial chemistry. Here, we synthesize surface-functionalized silicon nanocrystals that enable a highly dispersed and homogeneous slurry that can easily be integrated into standard electrode fabrication process. We use this formulation to print a 76 wt. % silicon composite electrode. We show that the contents and the morphology of the silicon electrolyte interphase – a determining factor in the cycle life of silicon-based anodes – can be controlled with a post-synthetic thermal curing procedure. When paired against a capacity-matched lithium nickel manganese cobalt oxide LiNi0.8Mn0.1Co0.1O2 cathode, the cell retains 72% of its capacity through 1000 charge/discharge cycles while delivering an initial anode specific capacity of nearly 1000 mAh/g and an areal capacity of 2.55 mAh/cm2. Figure 1

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Xia, Jing, Shuxiang Li, Yuan Gao, Dakui Zhang, Qiongguang Li et Yanhong Wang. « Silicon/Needle Coke Composites as Efficient Anodes for Lithium Ion Batteries ». MATEC Web of Conferences 363 (2022) : 01022. http://dx.doi.org/10.1051/matecconf/202236301022.

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In this research, a facile method was reported to prepare silicon/carbon composites by heating Si nanosheets and coal-based needle cokes in the assistance of binder glucopyranose. The microstructures and electrochemical performances of samples were analyzed. It was found that Si nanosheets adhered to needle cokes forming silicon/carbon composites. Compared with needle cokes, the composites showed higher capacity and initial coulombic efficiency. Also, they improved the cycle stability of silicon materials. The silicon/carbon anode had a reversible capacity of 381.8 mAh/g at a current density of 100 mA/g after 170 cycles. In our work, relatively inexpensive Si nanosheets and coal-based needle cokes with low price were employed as the silicon and carbon sources respectively. Therefore, this method provides a possible strategy to reduce costs of silicon/carbon anodes, accelerating their commercial applications.

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Long, Jin, Huilong Liu, Yingxi Xie, Weijin Tang, Ting Fu, Yong Tang, Longsheng Lu, Xinrui Ding et Xingxian Tang. « Three-Dimensional Copper Foil-Powder Sintering Current Collector for a Silicon-Based Anode Lithium-Ion Battery ». Materials 11, n^o 8 (2 août 2018) : 1338. http://dx.doi.org/10.3390/ma11081338.

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In this work, we propose a facile method for manufacturing a three-dimensional copper foil-powder sintering current collector (CFSCC) for a silicon-based anode lithium-ion battery. We found that the CFSCC is suitable as a silicon-based paste electrode, and the paste-like electrodes are commonly used in industrial production. Compared with flat current collectors, the CFSCC better constrained the silicon volume change during the charging-discharging process. The capacitance of electrodes with CFSCC remained as high as 92.2% of its second cycle after 40 cycles, whereas that of electrodes with a flat current collector only remained at 50%.

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Chen, Yong, Xuejun Zhang, Yanhong Tian et Xi Zhao. « Synthesis and Characterization of Silicon Nanoparticles Inserted into Graphene Sheets as High Performance Anode Material for Lithium Ion Batteries ». Journal of Nanomaterials 2014 (2014) : 1–6. http://dx.doi.org/10.1155/2014/734751.

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Silicon nanoparticles have been successfully inserted into graphene sheets via a novel method combining freeze-drying and thermal reduction. The structure, electrochemical performance, and cycling stability of this anode material were characterized by SEM, X-ray diffraction (XRD), charge/discharge cycling, and cyclic voltammetry (CV). CV showed that the Si/graphene nanocomposite exhibits remarkably enhanced cycling performance and rate performance compared with bare Si nanoparticles for lithium ion batteries. XRD and SEM showed that silicon nanoparticles inserted into graphene sheets were homogeneous and had better layered structure than the bare silicon nanoparticles. Graphene sheets improved high rate discharge capacity and long cycle-life performance. The initial capacity of the Si nanoparticles/graphene keeps above 850 mAhg−1after 100 cycles at a rate of 100 mAg−1. The excellent cycle performances are caused by the good structure of the composites, which ensured uniform electronic conducting sheet and intensified the cohesion force of binder and collector, respectively.

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Carroll, Gerard (MIke) Michael, Ryan Doeren, Fernando Urias, Maxwell Schulze et Nathan R. Neale. « (Digital Presentation) Engineering Electrode Architecture and Interfacial Chemistry of High-Content, High-Loading Silicon Anodes to Improve Cycle and Calendar Life ». ECS Meeting Abstracts MA2022-02, n^o 7 (9 octobre 2022) : 2429. http://dx.doi.org/10.1149/ma2022-0272429mtgabs.

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Silicon lithium alloys (SiLix) as the anode active material in a Li-Ion battery configuration offers possible energy densities paralleled only by pure lithium metal. However, the extreme mechanical deformation of alloying and dealloying SiLix through charge/discharge cycles paired with the highly reactive interface of SiLix are large barriers to industrial adoption of high-silicon-content negative electrodes. Moreover, these challenges are magnified when the thickness of the electrode is brought to relevant levels (>3 mg/cm2). Here, I describe efforts to address these challenges by utilizing single-nanometer-scale silicon nanoparticles to reduce capacity fade related to mechanical failure. I also detail new interfacial chemistries which give rise to precise electrode-level engineering in which the SEI morphology and thickness can be controlled. This development has enabled a 75% by mass silicon composite electrode to achieve cycle capacity retention of 73% through 1000 charge/discharge cycles against capacity-matched NMC-based cathodes. Figure 1

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Kulova, T. L., N. F. Nikol'skaya, E. K. Tuseeva et A. M. Skundin. « The flexible lithium-ion batteries ». Electrochemical Energetics 9, n^o 2 (2009) : 67–70. http://dx.doi.org/10.18500/1608-4039-2009-9-2-67-70.

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Lithiated iron phosphate and thin-film amorphous silicon are used for positive and negative electrodes of lithium-ion battery, correspondingly. Laboratory samples of flexible lithium-ion batteries are manufactured and tested with load 0.4 mA. This load corresponded to current density of 1 A/g for negative electrode and 23 mA/g for positive one. The samples were cycled in the voltage range 2.3 to 3.48 V. Energy density of the sample amounted up to 100 W·h/l. Capacity fading was ca. 0.08% per cycle for 500 cycles.

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Yang, S., R. F. Gibson, G. M. Crosbie et R. L. Allor. « Thermal Cycling Effects on Dynamic Mechanical Properties and Crystallographic Structures of Silicon Nitride-Based Structural Ceramics ». Journal of Engineering for Gas Turbines and Power 119, n^o 2 (1 avril 1997) : 279–84. http://dx.doi.org/10.1115/1.2815571.

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Thermal cycling effects on dynamic mechanical properties of hot pressed silicon nitride (HPSN) based structural ceramics were investigated in a simulated thermal cycling environment from room temperature up to 1100°C. Two monolithic silicon nitrides and two silicon nitride composites reinforced with silicon carbide whiskers were studied in such an environment. Experiments show that the dynamic mechanical properties of the tested materials are influenced by thermal cycle. The materials stiffened slightly while damping capacity decreased slightly during each thermal cycle. X-ray diffraction (XRD) was subsequently used to examine the corresponding crystallographic alterations. The XRD patterns show that the amorphous glass phases in the silicon nitride matrix were partially crystallized during thermal cycling.

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Yu, Shou Xin, D. W. Zou, X. L. Zhu, Yu Li Sun et L. Zhou. « Friction and Wear of Polished Single Crystal Silicon at Different Area ». Advanced Materials Research 142 (octobre 2010) : 117–21. http://dx.doi.org/10.4028/www.scientific.net/amr.142.117.

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A friction and wear experiment was carried out at different areas of single crystal silicon under same surface roughness. Friction mechanisms at different area were analyzed by STM and 3D profiler. The result showed that the friction and wear properties were obviously different at different area although they had same surface roughness. The friction and wear properties of the single crystal silicon where closest to inner-cycle internal were best while the farther from the inner-cycle silicon area or closer to crystal silicon cylindrical, the worse friction and wear properties were. Abrasive wear and adhesive wear were the primary wear mechanisms.

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Arie, Arenst Andreas, et Joong Kee Lee. « Electrochemical Properties of P-Doped Silicon Thin Film Anodes of Lithium Ion Batteries ». Materials Science Forum 737 (janvier 2013) : 80–84. http://dx.doi.org/10.4028/www.scientific.net/msf.737.80.

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Silicon would seem to be a possible candidate to replace graphite or carbon as anode materials for lithium ion batteries based on its potential high capacity of 4200 mAhg-1. The main problem that must be solved for commercial application of silicon as anode material was the poor cyclic performance due to severe volume expansion during repeated charged-discharged cycles and its low electrical conductivity. In this work, we proposed Phosphorus doped (P-doped) Si films as anodes in lithium ion batteries. The electrochemical properties of the silicon based electrodes were examined by means of charge-discharge and impedance test. In comparison with the bare silicon electrode, the P type silicon electrode exhibited higher specific capacity of 2585 mAhg-1 until the 50th cycle. It was attributed to the improved electrical conductivity of Si film and reduced charge transfer resistance

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Liu, Jing Yu, Ke Jian, Zhao Hui Chen, Qing Song Ma et Song Wang. « Effects of Pyrolysis Temperatures on the Microstructure and Mechanical Properties of 2D-C_f/Si-O-C Composites ». Key Engineering Materials 368-372 (février 2008) : 1022–24. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1022.

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Two-dimensional carbon fiber cloth reinforced silicon oxycarbide (2D-Cf/Si-O-C) composites were fabricated with silicone resin (SR) as precursors, ethanol as solvent and SiC as inert fillers by precursor infiltration pyrolysis (PIP). Effects of the pyrolysis temperatures in the first cycle and the last but third cycle on the microstructure and mechanical properties of 2D-Cf/Si-O-C composites were investigated. The results showed that, when the pyrolysis temperature of the first cycle was 1200°C, 2D-Cf/Si-O-C composites exhibited good mechanical properties, which can be attributed to the better fiber/matrix interfacial bonding. When the pyrolysis temperature of the last but third cycle was 1400°C, the mechanical properties of 2D Cf/Si-O-C composites were further enhanced. The flexural strength and fracture toughness of the composites reached 263.9MPa and 12.8 MPa·m1/2, respectively.

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Tréguer, Paul J., Jill N. Sutton, Mark Brzezinski, Matthew A. Charette, Timothy Devries, Stephanie Dutkiewicz, Claudia Ehlert et al. « Reviews and syntheses : The biogeochemical cycle of silicon in the modern ocean ». Biogeosciences 18, n^o 4 (18 février 2021) : 1269–89. http://dx.doi.org/10.5194/bg-18-1269-2021.

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Abstract. The element silicon (Si) is required for the growth of silicified organisms in marine environments, such as diatoms. These organisms consume vast amounts of Si together with N, P, and C, connecting the biogeochemical cycles of these elements. Thus, understanding the Si cycle in the ocean is critical for understanding wider issues such as carbon sequestration by the ocean's biological pump. In this review, we show that recent advances in process studies indicate that total Si inputs and outputs, to and from the world ocean, are 57 % and 37 % higher, respectively, than previous estimates. We also update the total ocean silicic acid inventory value, which is about 24 % higher than previously estimated. These changes are significant, modifying factors such as the geochemical residence time of Si, which is now about 8000 years, 2 times faster than previously assumed. In addition, we present an updated value of the global annual pelagic biogenic silica production (255 Tmol Si yr−1) based on new data from 49 field studies and 18 model outputs, and we provide a first estimate of the global annual benthic biogenic silica production due to sponges (6 Tmol Si yr−1). Given these important modifications, we hypothesize that the modern ocean Si cycle is at approximately steady state with inputs =14.8(±2.6) Tmol Si yr−1 and outputs =15.6(±2.4) Tmol Si yr−1. Potential impacts of global change on the marine Si cycle are discussed.

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Closset, Ivia, Damien Cardinal, Mathieu Rembauville, François Thil et Stéphane Blain. « Unveiling the Si cycle using isotopes in an iron-fertilized zone of the Southern Ocean : from mixed-layer supply to export ». Biogeosciences 13, n^o 21 (3 novembre 2016) : 6049–66. http://dx.doi.org/10.5194/bg-13-6049-2016.

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Abstract. A massive diatom bloom forms annually in the surface waters of the naturally iron-fertilized Kerguelen Plateau (Southern Ocean). In this study, silicon isotopic signatures (δ30Si) of silicic acid (DSi) and suspended biogenic silica (BSi) were investigated through the whole water column with unprecedented spatial resolution, during the KEOPS-2 experiment (spring 2011). We used δ30Si measurements to track the sources of silicon that fuelled the bloom, and investigated the seasonal evolution of the Si biogeochemical cycle in the iron-fertilized area. We compared the results from stations with various degrees of iron enrichment and bloom conditions to an HNLC reference station. Dissolved and particulate δ30Si signatures were highly variable in the upper 500 m, reflecting the effect of intense silicon utilization in spring, while they were quite homogeneous in deeper waters. The Si isotopic and mass balance identified a unique Winter Water (WW) Si source for the iron-fertilized area that originated from southeast of the Kerguelen Plateau and spread northward. When the WW reached a retroflection of the Polar Front (PF), the δ30Si composition of the silicic acid pool became progressively heavier. This would result from sequential diapycnal and isopycnal mixings between the initial WW and ML water masses, highlighting the strong circulation of surface waters that defined this zone. When comparing the results from the two KEOPS expeditions, the relationship between DSi depletion, BSi production, and their isotopic composition appears decoupled in the iron-fertilized area. This seasonal decoupling could help to explain the low apparent fractionation factor observed in the ML at the end of summer. Taking into account these considerations, we refined the seasonal net BSi production in the ML of the iron-fertilized area to 3.0 ± 0.3 mol Si m−2 yr−1, which was exclusively sustained by surface water phytoplankton populations. These insights confirm that the isotopic composition of dissolved and particulate silicon is a promising tool to improve our understanding of the Si biogeochemical cycle since the isotopic and mass balance allows resolution of processes in the Si cycle (i.e. uptake, dissolution, mixing).

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Basile-Doelsch, Isabelle, Jean Dominique Meunier et Claude Parron. « Another continental pool in the terrestrial silicon cycle ». Nature 433, n^o 7024 (janvier 2005) : 399–402. http://dx.doi.org/10.1038/nature03217.

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Huber, W., et G. Kolb. « Life cycle analysis of silicon-based photovoltaic systems ». Solar Energy 54, n^o 3 (mars 1995) : 153–63. http://dx.doi.org/10.1016/0038-092x(94)00121-s.

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Boroch, Robert E., Roland Müller-Fiedler, Joerg Bagdahn et Peter Gumbsch. « High-cycle fatigue and strengthening in polycrystalline silicon ». Scripta Materialia 59, n^o 9 (novembre 2008) : 936–40. http://dx.doi.org/10.1016/j.scriptamat.2008.05.047.

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Moyassari, Erfan, Thomas Roth, Simon Kücher, Chia-Chin Chang, Shang-Chieh Hou, Franz B. Spingler et Andreas Jossen. « The Role of Silicon in Silicon-Graphite Composite Electrodes Regarding Specific Capacity, Cycle Stability, and Expansion ». Journal of The Electrochemical Society 169, n^o 1 (1 janvier 2022) : 010504. http://dx.doi.org/10.1149/1945-7111/ac4545.

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One promising way of compensating for the repeated volume expansion and contraction of silicon as an anode active material in lithium ion batteries (LIBs) is to embed silicon within a graphite matrix. Silicon-graphite (SiG) composites combine the advantageous properties of graphite, i.e., large electrical conductivity and high structural stability, with the advantageous properties of silicon, i.e., high theoretical capacity. Graphite has a much lower volume expansion upon lithiation (≈ 10%) than pure silicon (≈ 300%) and provides a mechanically stable matrix. Herein, we present an investigation into the electrochemical performance and thickness change behavior of porous SiG anode compositions with silicon contents ranging from 0 wt% to 20 wt%. The electrode composites were studied using two methods: in situ dilatometry for the thickness change investigation and conventional coin cells for the assessment of electrochemical performance. The measurements show that the initial thickness change of SiG electrodes increased significantly with the silicon content, but it leveled off during cycling for all compositions. There appears to be a correlation between silicon content and capacity loss, but no clear correlation between thickness change and capacity loss rate was found.

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Yazdani, Farhang. « Design and Direct Assembly of 2.5D/3D Rigid Silicon Interposer on PCB ». International Symposium on Microelectronics 2014, n^o 1 (1 octobre 2014) : 000783–86. http://dx.doi.org/10.4071/isom-thp12.

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Silicon interposer is emerging as a vehicle for integrating dies with sub 50um bump pitch in 2.5D/3D configuration. Benefits of 2.5D/3D integration are well explained in the literature, however, cost and reliability is a major concern especially with the increase in interposer size. Among the challenges, reliability issues such as warpage, cracks and thermal-stresses must be managed, in addition, multi-layer build-up flip chip substrate cost and its impact on the overall yield must be considered. Because of these challenges, 2.5D/3D silicon interposer has developed a reputation as a costly process. To overcome the reliability challenges and cost associated with typical thin interposer manufacturing and assembly, a rigid silicon interposer type structure is disclosed. In this study, interposer with thickness of greater than 300um is referred to as rigid interposer. Rigid silicon interposer is directly assembled on PCB without the need for intermediary substrate. This eliminates the need for an intermediary substrate, thin wafer handling, wafer bonding/debonding procedures and Through Silicon Via (TSV) reveal processes, thus, substantially reducing the cost of 2.5D/3D integrated products while improving reliability. A 10X10mm2 rigid silicon interposer test vehicle with 310um thickness was designed and fabricated. BGA side of the interposer with 1mm ball pitch was bumped with eutectic solder balls through a reflow process. Interposer was then assembled on a 50X50mm2 FR-4 PCB. We present design and direct assembly of the rigid silicon interposer on PCB followed by temperature cycle results using CSAM images at 250, 500, 750 and 1000 cycles. It is shown that all samples successfully passed the temperature cycle stress test.

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Lu, Ya Ping, Tian Lin Song et Hai Qing Liu. « Influence of Silicon Controlled Rectifier Voltage Regulation Device under DDC-Temperature Control ». Advanced Materials Research 706-708 (juin 2013) : 826–29. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.826.

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In the boiler heating control device of combining DDC and the silicon controlled rectifier voltage regulation device, there are phase shift trigger, pulse width modulation (PWM) and cycle wave cross zero trigger (CYC). Under the different silicon controlled rectifier voltage regulation devices, there are different influences for DDC. It makes the best of the cycle characteristics of the alternating current (AC) for the cycle wave cross zero trigger (CYC). For DDC - temperature control system, there are advantages of high control accuracy, less interference and power source pollution.

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Wang, Yuanshen, et Borong Wu. « Nano-Si/graphite/N-doped biocarbon hybrid anode material for high-performance lithium-ion batteries ». Journal of Physics : Conference Series 2300, n^o 1 (1 juin 2022) : 012005. http://dx.doi.org/10.1088/1742-6596/2300/1/012005.

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Abstract Improving the cycle life of silicon-based anodes is extremely important to the development of Li-ion batteries. Nano-silicon / graphite / Nitrogen-doped carbon composites are prepared as hybrid anode material in this work. The nano-silicon particles are distributed in the graphite framework, which improves the electrical conductivity of the composite. The amorphous nitrogen-doped carbon layer of the composite could be a buffer structure for the volume change of Si while providing a fast transport channel for lithium ions and further enhancing the electrical conductivity of the composites. The specific capacity of the composite electrode is 656.5 mAh g-1 at 500 mA g-1. The capacity retention rate is 91% after 100 cycles. The composite electrode could deliver a specific capacity of 497.3 mAh g-1 after 200 cycles even at a large current density of 1A g-1.

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Schulze, Maxwell C., Kae Fink, Jack Palmer, Mike Michael Carroll, Nikita Dutta, Christof Zweifel, Chaiwat Engtrakul, Sang-Don Han, Nathan R. Neale et Bertrand J. Tremolet de Villers. « Reduced Electrolyte Reactivity of Pitch-Carbon Coated Si Nanoparticles for Li-Ion Battery Anodes ». ECS Meeting Abstracts MA2022-02, n^o 4 (9 octobre 2022) : 491. http://dx.doi.org/10.1149/ma2022-024491mtgabs.

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Silicon-based anodes for Li-ion batteries (LIB) have the potential to increase the energy density over graphite-based LIB anodes. However, silicon anodes exhibit poor cycle and calendar lifetimes due to mechanical instabilities and high chemical reactivity with the carbonate-based electrolytes that are typically used in LIBs. In this work, we synthesize a pitch-carbon coated silicon nanoparticle composite active material for LIB anodes that exhibits reduced chemical reactivity with the carbonate electrolyte compared to an uncoated silicon anode. Silicon primary particle sizes <10 nm minimize micro-scale mechanical degradation of the anode composite, while conformal coatings of pitch-carbon minimized the parasitic reactions between the silicon and the electrolyte. When matched with a high voltage NMC811 cathode, the pitch-carbon coated Si anode retains ~75% of its initial capacity over 1000 cycles. Efforts to increase the areal loading of the pitch-carbon coated silicon anodes to realize real energy density improvements over graphite anodes results in severe mechanical degradation on the electrode level. Developing procedures to engineer the architecture of the composite silicon anode may be a solution to this mechanical challenge. Figure 1

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Yang, Hai Li, Guo Zhang Tang, Yun Gang Li, Ning He et Yu Zhu Zhang. « Effect of the Duty Cycle on Boronized Layer Formed by Pulse Electrodeposition ». Applied Mechanics and Materials 117-119 (octobre 2011) : 1293–97. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.1293.

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Boronized layer on silicon steel substrate was fabricated using pulse electrodeposition technique with different duty cycle in KCl-NaCl-NaF-Na2B4O7 molten salts. The effect of the duty cycle on composition and microstructure of obtained layer was investigated. The boronized layer was analyzed by X-ray diffraction analysis (XRD), optical microscopy (OM), glow discharge spectrometry (GDS), and atomic force microscopy (AFM). The results showed that in the range of 10-50%, duty cycle almost had no effect on composition and thickness of the layer. The boronized layers in this range exhibited FeB phase on the surface of silicon steel. However, duty cycle had great effect on the microstructure of the boronized layer. A fine grain size boronized layer can be obtained at a duty cycle of 20%.

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Tzeng, Yonhua, Jia-Lin He, Cheng-Ying Jhan et Yi-Hsuan Wu. « Effects of SiC and Resorcinol–Formaldehyde (RF) Carbon Coatings on Silicon-Flake-Based Anode of Lithium Ion Battery ». Nanomaterials 11, n^o 2 (25 janvier 2021) : 302. http://dx.doi.org/10.3390/nano11020302.

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Silicon flakes of about 100 × 1000 × 1000 nm in sizes recycled from wastes of silicon wafer manufacturing processes were coated with combined silicon carbide (SiC) and graphitic (Resorcinol–Formaldehyde (RF)) carbon coatings to serve as active materials of the anode of lithium ion battery (LIB). Thermal carbonization of silicon at 1000 °C for 5 h forms 5-nm SiC encapsulating silicon flakes. SiC provides physical strength to help silicon flakes maintain physical integrity and isolating silicon from irreversible reactions with the electrolyte. Lithium diffuses through SiC before alloying with silicon. The SiC buffer layer results in uniform alloying reactions between lithium and silicon on the surface around a silicon flake. RF carbon coatings provide enhanced electrical conductivity of SiC encapsulated silicon flakes. We characterized the coatings and anode by SEM, TEM, FTIR, XRD, cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and electrical resistance measurements. Coin half-cells with combined SiC and RF carbon coatings exhibit an initial Coulombic efficiency (ICE) of 76% and retains a specific capacity of 955 mAh/g at 100th cycle and 850 mAh/g at 150th cycle of repetitive discharge and charge operation. Pre-lithiation of the anode increases the ICE to 97%. The SiC buffer layer reduces local stresses caused by non-uniform volume changes and improves the capacity retention and the cycling life.

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Holo, Antonin, Christophe Dubarry, João-Carlos Lopes Barbosa, Muriel Dupont, Sandrine Chabaud et François Templier. « 45‐4 : MicroLED Display Life Cycle Assessment ». SID Symposium Digest of Technical Papers 54, n^o 1 (juin 2023) : 654–57. http://dx.doi.org/10.1002/sdtp.16643.

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This paper addresses the life cycle assessment of a MicroLED display component: 3D integration of CMOS and active GaN on silicon LED module. Along different life cycle phases of this technology, results explicit the impacts of the CMOS manufacturing flow on one hand and the epitaxy step on the other hand.

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Kim, Hyu Suk, Hyug Jong Kim, Hyung Su Kim, Young Kyu Jeong, Suk Hwan Kim, Sang Woo Lee, Bong Kyo Jeong, Hyuoung Ho Lee et Byung Ho Choi. « Improvement of Luminescent Properties of Phosphor Powders Coated with Nanoscaled SiO₂ by Atomic Layer Deposition ». Solid State Phenomena 124-126 (juin 2007) : 375–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.375.

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An investigation is reported by coating BaMgAl10O17:Eu2+ phosphor by silicon oxide using catalyzed atomic layer deposition. Nanoscaled SiO2 films were prepared at room temperature using tetraethoxysilane (TEOS), H2O and NH3 as precursors, reactant gas and catalyst, respectively. AES analysis showed the surface composition of coated phosphor was silicon oxide. In TEM and FE-SEM analysis, the growth rate was about 0.7 Å/cycle and the surface morphology became smoother and clearer than that of uncoated phosphor. The photoluminescence intensity (PL) increased up to 11.04% as ALD cycle increased up to 200 ALD cycle. This means that the reactive surface of uncoated phosphors is uniformly grown with stable silicon oxide to reduce the dead surface layer without change of bulk properties. Moreover, it is found that nanoscaled SiO2 films are quite effective for the improvement of the aging characteristics of photoluminescence.

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Wang, Wei, Jiang, Liu, Lei, Lin et Zhao. « Silicon Isotope Geochemistry : Fractionation Linked to Silicon Complexations and Its Geological Applications ». Molecules 24, n^o 7 (10 avril 2019) : 1415. http://dx.doi.org/10.3390/molecules24071415.

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The fundamental advances in silicon isotope geochemistry have been systematically demonstrated in this work. Firstly, the continuous modifications in analytical approaches and the silicon isotope variations in major reservoirs and geological processes have been briefly introduced. Secondly, the silicon isotope fractionation linked to silicon complexation/coordination and thermodynamic conditions have been extensively stressed, including silicate minerals with variable structures and chemical compositions, silica precipitation and diagenesis, chemical weathering of crustal surface silicate rocks, biological uptake, global oceanic Si cycle, etc. Finally, the relevant geological implications for meteorites and planetary core formation, ore deposits formation, hydrothermal fluids activities, and silicon cycling in hydrosphere have been summarized. Compared to the thermodynamic isotope fractionation of silicon associated with high-temperature processes, that in low-temperature geological processes is much more significant (e.g., chemical weathering, biogenic/non-biogenic precipitation, biological uptake, adsorption, etc.). The equilibrium silicon isotope fractionation during the mantle-core differentiation resulted in the observed heavy isotope composition of the bulk silicate Earth (BSE). The equilibrium fractionation of silicon isotopes among silicate minerals are sensitive to the Si–O bond length, Si coordination numbers (CN), the polymerization degrees of silicate unites, and the electronegativity of cations in minerals. The preferential enrichment of different speciation of dissoluble Si (DSi) (e.g., silicic acid H4SiO40 (H4) and H3SiO4− (H3)) in silica precipitation and diagenesis, and chemical weathering, lead to predominately positive Si isotope signatures in continental surface waters, in which the dynamic fractionation of silicon isotope could be well described by the Rayleigh fractionation model. The role of complexation in biological fractionations of silicon isotopes is more complicated, likely involving several enzymatic processes and active transport proteins. The integrated understanding greatly strengthens the potential of δ30Si proxy for reconstructing the paleo terrestrial and oceanic environments, and exploring the meteorites and planetary core formation, as well as constraining ore deposits and hydrothermal fluid activity.

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Ding, T. P., J. X. Zhou, D. F. Wan, Z. Y. Chen, C. Y. Wang et F. Zhang. « Silicon isotope fractionation in bamboo and its significance to the biogeochemical cycle of silicon ». Geochimica et Cosmochimica Acta 72, n^o 5 (mars 2008) : 1381–95. http://dx.doi.org/10.1016/j.gca.2008.01.008.

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Cain, Jeffrey David, Zachary D. Hood, Shiba Adhikari, Thomas Moylan et Nicholas Pieczonka. « (Digital Presentation) Ex Situ Electrochemical Pre-Lithiation of Silicon for Lithium-Ion Battery Anodes ». ECS Meeting Abstracts MA2023-01, n^o 2 (28 août 2023) : 526. http://dx.doi.org/10.1149/ma2023-012526mtgabs.

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Crystalline silicon as an anode material for lithium-ion batteries (LIBs) has a theoretical capacity greater than 3600 mAh/g, an order of magnitude larger than the current anode materials of choice, graphite (~370 mAh/g). However, the use of silicon is hampered by several issues that hinder its widespread usage in LIBs. Chief among these is the large volume expansion that accompanies lithiation (>300%), which results in the self-pulverization of silicon during cycling and the degradation in stability and performance that accompanies it. Silicon also suffers from active lithium loss in its first cycle from the formation of Li x Si and the solid-electrolyte interphase (SEI), which irreversibly consumes lithium and decreases gravimetric/volumetric capacity (typically >20% capacity loss after the formation cycle). This capacity loss coupled with mechanical and chemical degradation leads to poor capacity retention and short cycle life. Pre-lithiation of silicon and other potential anode materials (e.g. SiOx), a process of inserting additional Li into Si prior to battery operation, is thus desired to compensate for lithium consumption and to maintain the high capacity associated with silicon. Here, we demonstrate a simple and scalable method for the ex situ (i.e. outside the cell) electrochemical synthesis of pre-lithiated silicon. In this method, a current is driven though an electrochemical stir-tank reactor composed of Si powder in electrolyte suspension and a Li containing anode. When Si particles contact the conductive inner surface of the reaction vessel, lithium ions in the electrolyte are reduced on the surface to form lithium-silicon compounds. The degree of lithiation is controlled by the applied current density, applied voltage, and/or runtime. This talk will describe the chemical and structural characteristics of pre-lithiated silicon synthesized with this technique, basic electrochemical properties of our lithiated material, and the specific advantages presented by the method vs other methods.

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Alemdağ, Yasin, Sadun Karabıyık, Harun Yanar et Gençağa Pürçek. « Mechanical Properties of Multi-Directional Forged Al-7Si-4Zn-3Cu Alloy ». Defect and Diffusion Forum 385 (juillet 2018) : 250–55. http://dx.doi.org/10.4028/www.scientific.net/ddf.385.250.

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In this study, Al-7Si-4Zn-3Cu alloy was processed by multi-directional forging (MDF) at 3, 6 and pass corresponding one, two and three cycle, respectively. The structural and mechanical properties of the alloys were investigated at as-cast, homogenised and MDF states. The MDF resulted in a severely deformed and refined microstructure with eliminated casting defects like micro-porosity and formation of nearly homogeneous distributed finer silicon particles. The tensile (UTS) and yield (YS) of the alloy increased up to two cycle, above which they showed a decrease, while the percent elongation increased continuously as the cycle number increased. The comprehensive strength and micro and macro hardness of the alloy decreased with increasing MDF cycles. The results were evaluated according to microstructural changes depending on MDF cycles.

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Moyassari Sardehaei, Erfan, Thomas Roth, Simon Kücher, Franz B. Spingler et Andreas Jossen. « The Role of Silicon in Silicon-Graphite Composite Electrodes Regarding Specific Capacity, Cycle Stability, and Expansion ». ECS Meeting Abstracts MA2022-01, n^o 2 (7 juillet 2022) : 421. http://dx.doi.org/10.1149/ma2022-012421mtgabs.

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Silicon-based electrodes are promising candidates to enable the next generation of Lithium-ion batteries with high energy densities on the cell level beyond 350 Wh kg−1 [1, 2]. Nevertheless, the commercialization of silicon-based electrodes is still hindered due to the large volume expansion during cycling of up to 300% [3]. This volume expansion upon repeated (de-)lithiation of silicon particles worsens the electrode integrity by causing isolation of active material components [4-6]. Continuous electrolyte decomposition at the silicon/electrolyte interface, caused by the repeated volume expansion and contraction, results in a gradual loss of active lithium [7]. While X-ray diffraction (XRD) as well as theoretical methods provide atomic scale information, dilatometry is an appropriate tool for the in-situ investigation of the volumetric work of battery composite electrodes on the macroscopic level. Therefore, the technique itself as well as the obtained data have a high potential for their industrial implementation [8]. In this work, the expansion of a single-side-coated silicon-based anode is investigated with a commercial, high-precision dilatometer, which detects the thickness change perpendicular to the surface of the coating on the electrode level during cycling against a lithium metal counter electrode. The measured samples consist of 95 wt.% active material (0 - 20 wt.% of silicon in combination with 95 - 75 wt.% of graphite, respectively) and 5 wt.% of non-active components. The investigated samples in this work differ in their silicon and graphite content. Moreover, the samples were also investigated electrochemically via conventional coin cells. The comparable electrochemical behavior of the electrodes in both experiment methods is proof of the plausibility of the dilatometry results. Increasing the silicon content led to higher specific capacities of the SiG electrodes. The relative capacity loss and the thickness change increased linearly with the silicon content as well. Based on the characteristic thickness change for the SiGs, we concluded that silicon predominantly lithiated before graphite, and delithiated after graphite. The used non-commercial electrodes were designed and produced within the scope of the project “HighSafeII”, funded by the German Federal Ministry of Education and Research (BMBF) under grant number 03XP0306B. Literature [1] D. Andre, S.-J. Kim, P. Lamp, S. F. Lux, F. Maglia, O. Paschos, and B. Stiaszny, “Future generations of cathode materials: an automotive industry perspective”, J. Mater. Chem. A, 3 (13), 6709 (2015). [2] O. Gröger, H. A. Gasteiger, and J.-P. Suchsland, “Review—Electromobility: Batteries or Fuel Cells?”, J. Electrochem. Soc., 162 (14), A2605 (2015). [3] D. Ma, Z. Cao, and A. Hu, “Si-Based Anode Materials for Li-Ion Batteries: A Mini Review” Nano-Micro Lett, 6(4), 347 (2014). [4] M. N. Obrovac, L. Christensen, D. B. Le, and J. R. Dahn, “Alloy Design for Lithium-Ion Battery Anodes”, J. Electrochem. Soc., 154 (9), A849 (2007). [5] D. S. M. Iaboni and M. N. Obrovac, “Li15Si4 Formation in Silicon Thin Film Negative Electrodes”, J. Electrochem. Soc., 163 (2), 255 (2016). [6] M. N. Obrovac and V. L. Chevrier, “Alloy Negative Electrodes for Li-Ion Batteries”, Chem. Rev., 114, 11444 (2014). [7] R. Petibon, V. Chevrier, C. P. Aiken, D. S. Hall, S. Hyatt, R. Shunmugasundaram, and J. R. Dahn, “Studies of the Capacity Fade Mechanisms of LiCoO2/Si-Alloy: Graphite Cells”, J. Electrochem. Soc., 163 (7), 1146 (2016). [8] Daniel Sauerteig, Svetlozar Ivanov, Holger Reinshagen, Andreas Bund, „Reversible and irreversible dilation of lithium-ion battery electrodes investigated by in-situ dilatometry“, J. Power Sources, 342, 939-946 (2017).

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Yoon, Jong-Hwan. « Intrinsic microcrystalline silicon by postgrowth anneals ». Journal of Materials Research 16, n^o 6 (juin 2001) : 1531–34. http://dx.doi.org/10.1557/jmr.2001.0212.

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Hydrogenated microcrystalline silicon (μc-Si:H) grown by a conventional plasma-enhanced chemical vapor deposition from high hydrogen-diluted silane was annealed by increasing the temperature from 25 to 450 °C at a constant rate of 12 °C/min (one annealing cycle). Dark-conductivity activation energy gradually increases with increasing the number of annealing cycle to a saturation value of about 0.6 eV, observed in truly intrinsic μc-Si:H films. For the saturated state, the dark conductivity of the order of 10−8 S/cm was obtained. Little or no change in the oxygen content was observed after the annealing.

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Tian, Xueyu, Samuel D. Stranks et Fengqi You. « Life cycle energy use and environmental implications of high-performance perovskite tandem solar cells ». Science Advances 6, n^o 31 (juillet 2020) : eabb0055. http://dx.doi.org/10.1126/sciadv.abb0055.

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A promising route to widespread deployment of photovoltaics is to harness inexpensive, highly-efficient tandems. We perform holistic life cycle assessments on the energy payback time, carbon footprint, and environmental impact scores for perovskite-silicon and perovskite-perovskite tandems benchmarked against state-of-the-art commercial silicon cells. The scalability of processing steps and materials in the manufacture and operation of tandems is considered. The resulting energy payback time and greenhouse gas emission factor of the all-perovskite tandem configuration are 0.35 years and 10.7 g CO2-eq/kWh, respectively, compared to 1.52 years and 24.6 g CO2-eq/kWh for the silicon benchmark. Prolonging the lifetime provides a strong technological lever for reducing the carbon footprint such that the perovskite-silicon tandem can outcompete the current benchmark on energy and environmental performance. Perovskite-perovskite tandems with flexible and lightweight form factors further improve the energy and environmental performance by around 6% and thus enhance the potential for large-scale, sustainable deployment.

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Kim, In Bae, Yong Su Park, Kyung Hyun Kim et In Gon Kim. « Effects of Silicon and Chromium on the Fatigue Properties of Al-Zn-Mg-Cu Cast Alloy ». Materials Science Forum 449-452 (mars 2004) : 617–20. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.617.

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Effects of Si and Cr additions on the fatigue properties of Al-Zn-Mg-Cu cast alloy were investigated by low and high cycle fatigue tests. It was found that in the low cycle fatigue test, fatigue life of base alloy showed the maximum value of 3,075 cycles, whereas in Si and Cr containing alloys, it was 2,993 and 1,413 cycles, respectively. The same trend was obtained in high cycle fatigue test, i.e., the fatigue strength in base alloy showed the highest value of 104MPa and decreased to 100MPa for Cr containing alloy and 81MPa for Si containing alloy. The fatigue ratio was about 0.20 for all three alloys. The tensile strength of base alloy also showed the maximum value of 513MPa, and decreased with the addition of Si and Cr to 400 and 500MPa, respectively. Metallographic observation revealed that the fatigue crack initiated at the surface and propagated along the grain boundary.

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Fan, Huilin, Youhong Wang, Mingxiang Yu, Kangkang Wang, Junting Zhang, Yien Liu, Lin Ma, Peng Zhang, Pengcheng Hu et Jia Zhao. « Cu–Al–Si alloy anode material with enhanced electrochemical properties for lithium ion batteries ». Functional Materials Letters 12, n^o 04 (août 2019) : 1950054. http://dx.doi.org/10.1142/s1793604719500541.

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The microstructure and electrochemical property of Cu–Al–Si alloy anode material are studied in this paper. The research shows that the alloy particle has a basic circular outline, and two copper-rich phases with different silicon contents are detected in the particle, and both phases with nanostructure are observed in its surface layer. The nano-silicon alloy negative electrode material needs to be used in a certain proportion with graphite, binder and conductive agent, and the stirring process also has an important influence on its electrochemical performance. Multiple mixing can achieve a better cycle retention compared to direct mixing. The first-cycle coulombic efficiency of the electrode material is improved up to about 90%, and the specific capacity is still higher than 500[Formula: see text]mAh[Formula: see text]g[Formula: see text] after 100 cycles. The battery manufacturing process is similar to the graphite negative electrode, so it is easy to be applied.

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Articles de revues sur le sujet « Silicon cycle »

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