Silicon Anodes for Improved EV Battery Performance

Abstract Silicon anodes, despite their high theoretical capacity, face critical challenges such as severe volume expansion (>300%), sluggish reaction kinetics, and unstable solid electrolyte interphase (SEI) formation. Herein, a novel strategy is proposed that synergistically combines supramolecular selfassembly techniques with heterojunction engineering to fabricate N, S codoped carboncoated silicon composites (Si/SiO x @C/N, S). The designed heterostructure mitigates mechanical degradation, enhances electronic conductivity, stabilizes the SEI. In situ Xray diffraction (XRD) confirms highly reversible lithiation/delithiation process, while in EIS verifies formation of stable Furthermore, density functional theory (DFT) calculations reveal between SiO carbon induces an internal electric field, significantly accelerating Li diffusion improving charge transport. Electrochemical evaluation reveals optimized MSi@SiO electrode achieves initial Coulombic efficiency 86.1% maintains capacity 1331.7 mAh g after 500 cycles at 1 A g, along excellent rate capability. ... Read More

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Silicon anode for lithium-ion batteries that can overcome the issues of volume expansion and loss of electrical contact during charge/discharge cycling. The anode structure comprises a copper current collector, an adhesion layer, and a multistratum active layer. The multistratum layer is made by alternating depositions of silicon and a metal, then rapidly annealing to form conductive metal silicide matrix enclosing amorphous/nanocrystalline silicon regions. This prevents pulverization and maintains electrical contact during volume expansion. The silicon electrode design enables high capacity silicon anodes for lithium-ion batteries without issues like pulverization and loss of contact.

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Abstract This work presents an indepth chemical and morphological investigation of the solid electrolyte interphase (SEI) formed on binderfree silicon electrodes, which include both nanowire (SiNW) amorphous (aSi) configurations, for nextgeneration lithiumion battery systems. The study focuses first five galvanostatic cycles to capture critical earlystage SEI consolidation process, essential understanding interfacial phenomena that dictate longterm performance. By employing innovative electrode fabrication techniques such as plasmaenhanced vapor deposition utilizing ionic liquid (IL)based electrolytesspecifically 1ethyl3methylimidazolium bis(fluorosulfonyl)imide (EMIFSI) formulations known their low viscosity high conductivitythis addresses challenges posed by significant volume changes inherent Sibased materials. Advanced characterization methodologies, notably OpticalPhotothermal Infrared Spectroscopy (OPTIR) Raman spectroscopy are utilized probe structural evolution with spatial resolution. multifaceted approach reveals interpl... Read More

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Lithium-ion battery anode with improved cycle life and rate performance for high capacity batteries like those used in electric vehicles. The anode has a silicon-based active material coated with a polymer or amorphous carbon layer containing carbon nanotubes (CNTs). The CNTs improve conductivity and stabilize against volume expansion of the silicon during charging/discharging. The CNTs are restrained by the polymer/carbon coating to prevent cracking and improve interfacial stability. This reduces cycle degradation compared to bare silicon anodes.

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Negative electrode material for lithium-ion batteries with improved cycling performance and capacity retention. The material is a silicon-based composite with a unique carbon coating. The silicon particles have a specific surface area oxide (SiOx) and a carbon layer covering the oxide. The carbon coating ratio and thickness are optimized to balance electron conductivity and volume expansion. The coating prevents oxide particle detachment during cycling. The carbon coating ratio is 0 < I1350/I1580 < 5 in Raman spectra, where I1350 and I1580 are peak intensities. The composite also contains graphite particles closely adjacent to the silicon particles, with >40% of the silicon particles adjacent to graphite. This reduces electron transfer resistance. The distance between silicon and graphite particles is <500 nm.

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Nanostructured silicon (Si) anodes with various dimensions (0- or 1D) are widely explored in the manufacturing of high-energy-density lithium-ion batteries (LIBs) to mitigate volume expansion during cycling. However, most them suffer from multiple issues, such as phase impurity, inhomogeneity particle size, and poor mechanical strength, resulting rate capability, cycle performance, Coulombic efficiency. In this work, a modified physical vapor deposition technique, known glancing angle (GLAD) method, is utilized produce pure Si nanospring arrays on Cu foil. The architecture, controlled dimensions, facilitates Li+ diffusion throughout amorphous offers good performance. case, electrochemical polishing foil has played pivotal role achieve very high specific capacity 2800 mAh g-1 at 300 mA capability up 4500 g-1. uniform nanosprings surface better structural robustness compared unpolished one.

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Direct coating of electrodes in silicon-dominant anode cells for lithium-ion batteries to improve cycle life and energy density. The direct coating process involves applying a precursor composite film onto the current collector and then heat treating it to convert to a pyrolyzed composite film. This converts the precursor into a stable electrode material directly on the current collector. Roll-to-roll processing allows continuous coating and heat treatment. Reducing atmosphere during heat treatment prevents SEI buildup. The direct coating reduces volume changes and maintains electrical contact during cycling, improving cycle life and capacity retention for silicon anodes.

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Abstract Fast charging (FC) capability is a frequently mentioned advantage of silicon as anode active material for lithium-ion cells. In this work, the FC multilayer pouch-cells containing 70 wt% anodes and NCA cathodes investigated over aging. Based on physicochemical-thermal model, voltage trajectories are derived based constant potential(CAP). Different safety margins used to derive different aggressive protocols. These experimentally applied cells, which aged until 70% state-of-health(SoH) using protocols in state-of-charge (SoC) windows. The resulting capacity re- tention was improved almost 850 cycles at SoH 50% SoC window. times 10 min 19 were achieved. subsequent degradation mode analysis indicated loss lithium inventory (LLI) main aging mechanism, independent LLI changed cell balancing, causing time increase by factor up 3, depending SoC. Finally, post-mortem confirmed cathode only minor modes.

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A lithium secondary battery with improved cycle life and thermal stability. The battery uses a composite anode active material with a unique structure. The anode contains composite particles made by coating a silicon material onto carbon particles with pores. The silicon coating is heated to 900-1200°C for 6-9 hours to form a coating with a very small (≤10nm) crystallite size. This prevents agglomeration/crystallization of the silicon during battery cycling and high temperatures. The coated carbon provides a matrix to confine the silicon and mitigate volume expansion. The small silicon crystallite size reduces side reactions with the electrolyte and improves battery life.

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A lithium secondary battery anode with improved cycle life for high capacity lithium batteries. The anode has two active material layers stacked on the current collector. The bottom layer has a graphite-based active material with low diffusivity. The top layer has composite particles containing silicon. The low diffusivity of the bottom layer slows lithium ion transport to prevent rapid volume expansion of the silicon in the top layer during charging. This prevents capacity fade and improves cycle life compared to using only silicon in the anode.

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A lithium secondary battery with improved cycle life and power by using an anode with composite particles containing a silicon coating on porous carbon. The porous carbon provides capacity expansion accommodation and the silicon coating prevents particle cracking during charging/discharging. The composite particles are mixed with graphite to form the anode active material layer. This provides both silicon capacity boost and graphite stability. The porous carbon allows volume expansion without fracture, while the silicon coating prevents particle cracking. This improves cycle life compared to plain silicon anodes.

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Lithium secondary battery anode with improved capacity and cycle life for high performance batteries like electric vehicles. The anode contains a silicon-based active material doped with magnesium, along with carbon. The magnesium-doped silicon reduces volume expansion during charging/discharging compared to undoped silicon. This prevents cracks and improves cycle life. The carbon provides electrical conductivity. By adjusting the silicon and carbon contents, rapid charge, room temperature, and high temperature cycle life can be optimized.

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Abstract The development of high-performance carbon-silicon anode materials is crucial for advancing lithium-ion battery technology. Herein, we fabricated cladding structure porous carbon/silicon composite fibers derived from residual oil and polyacrylonitrile (PAN) via electrospinning programmed carbonization, using polymethyl methacrylate (PMMA) as a pore-forming agent. Optimized synthesis with oil: PAN: PMMA: citric acid-modified nano-silicon ratio 1:1:0.8:0.4 yields CSi@RCF-R10S4 that demonstrates superior electrochemical performance. delivers remarkable discharge capacity 1474.5 mAhg 1 achieves an initial Coulombic efficiency 77.52%. This work establishes robust foundation both the rational design anodes high-value utilization in energy storage applications.

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Silicon (Si) anodes hold exceptional promise for highenergydensity lithiumion batteries (LIBs) due to their ultrahigh theoretical capacity (~4200 mAh g). However, commercialization is severely hindered by the significant volume expansion (~300%) and unstable solid electrolyte interphase (SEI). Conventional SEI, predominantly composed of organic species, suffers from low ionic conductivity, electronic insulation poor mechanical robustness, leading rapid decay. Herein, we propose an interface engineering strategy decorating Si nanoparticles with insitu conversed MgF layer (with coating integrity 94.6%). During initial lithiation, applied into SEI film high better adaptability. The prepared Si@MgF1 anode achieves a coulombic efficiency (91.7%), superior rate capability (2000 g at 10 C), remarkable cycling stability (1794.9 g1 after 500 cycles). Fullcell based on NCM811 cathode further validate practicality this approach. robust conversion construction mechanically adaptive LiFrich holds advancement durable siliconbased LIBs.

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Negative electrode design for lithium batteries with silicon-based anodes that improves cycle life and performance compared to pure silicon electrodes. The negative electrode has a specific ratio of particle sizes for silicon and carbon materials, and a porosity range. The silicon-carbon particle size ratio is 2-8. This allows the carbon to accommodate silicon volume expansion without degradation. The 48-62% porosity provides enough space for the silicon expansion. This prevents cracks and damage while maintaining electrical contact.

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Anode material for lithium-ion batteries that reduces volume expansion and improves cycle life. The anode material contains a silicon core coated with a carbon layer. The silicon core has silicon oxide and lithium silicate. The carbon coating isolates the core from the electrolyte, preventing loss of active silicon/lithium. The coating composition and thickness can be tuned for optimal electrolyte interface and charge transfer.

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Anode material for lithium-ion batteries with improved initial efficiency and cycle life. The anode contains silicon with lithium silicates. The silicon-based active substance is prepared by modifying the silicon oxide surface to increase lithiation sites. This involves treating the silicon oxide with acid to create defects, followed by prelithiation in the presence of a reducing lithium compound. The modified silicon oxide is then mixed and dispersed before prelithiation. This balances lithium, silicon, and lithium silicate content to avoid excessive silicon expansion. The modified silicon oxide provides stable lithiation, preventing erosion of binders and improving cycle life.

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Highly porous silicon composite anodes for lithium-ion batteries that have improved cycle life and capacity retention compared to conventional silicon anodes. The composite contains nanoscale silicon and carbon with a weight ratio of 75:25 to 99:1 silicon:carbon. The high silicon content allows for high capacity, while the carbon network provides structure and conductivity. The composites have a volume fraction of porosity between 20-70% to accommodate silicon expansion. Sealing the composites with a thin carbon coating prevents electrolyte reaction.

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Silicon-carbon composite for lithium-ion batteries with improved capacity and cycle life compared to traditional silicon anodes. The composite contains silicon particles coated with a thin carbon layer. The carbon coating suppresses volume expansion during charging/discharging. The carbon-coated silicon has a specific molar ratio of oxygen to silicon (O/Si) of 0.01-0.45. This ratio enables high discharge capacity and initial efficiency. The composite structure also has a core-shell structure with a thin carbon shell.

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Blend electrodes are used in lithiumion batteries to increase the performance by combining two active materials, such as silicon (Si) or oxide (SiOx) and graphite (Gr) for negative electrode. Indepth knowledge of complex interactions between materials is essential understand how inhomogeneities local peaks intercalation current arise they can be prevented. This work presents a spatially resolved transmission line model developed describe electrochemical behavior blend electrodes. Parameterization validation carried out Gr/SiOx anode. Simulation results investigate states during lithiation at different Crates. A special focus put on stress indicators precursors accelerated aging like materialspecific Crates spatial gradients degree lithiation. Thus, modeling approach tool both description properties simulationbased balancing materials capacities within

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