Cycling Stability in Silicon Anode EV Batteries

A secondary battery that enhances the performance and safety of lithium iron phosphate (LiFePO4) batteries through the integration of silicon-based negative electrodes. The battery comprises a silicon-carbon material prepared through controlled chemical vapor deposition, where silicon is deposited within the porous carbon matrix. This material enables improved thermal stability and structural integrity compared to conventional silicon electrodes, while maintaining the inherent benefits of LiFePO4. The battery's performance is evaluated through specific tests that assess both capacity retention and thermal management.

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Lithium-ion battery with enhanced cycling performance through a novel negative electrode design that incorporates silicon oxide active materials without graphite. The design combines a high-capacity silicon oxide active material with a silicon-based negative electrode, featuring a polymer binder and conductive carbon additives. The electrolyte formulation employs a specific combination of lithium salts and solvents that provide superior stability and capacity retention. The battery achieves exceptional cycling performance, with capacities exceeding 800 cycles at a C-rate, while maintaining high energy density and power output.

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A high-elasticity polymer-protected anode active material for lithium-ion batteries that achieves enhanced cycle life and reversible capacity through controlled particle size engineering. The material comprises dispersed or encapsulated anode active particles in a high-elasticity polymer matrix or shell, with the polymer exhibiting recoverable tensile strain and lithium ion conductivity. The polymer matrix forms a continuous material phase that encapsulates the active particles, providing mechanical stability and preventing electrolyte contact. This novel material architecture enables high-rate operation, reversible capacity, and improved cycle life compared to conventional anode materials.

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A lithium-ion battery negative electrode slurry preparation method that enables uniform dispersion of active materials, conductive agents, and binders without organic solvents. The method employs hydroxypropyl-B-cyclodextrin derivatives as a novel dispersant that enhances emulsification, stability, and rapid dispersion of the negative electrode slurry. This approach enables the preparation of uniform slurry without the need for conventional dispersants, achieving improved coating quality and yield on the current collector surface. The slurry is then applied to the current collector surface through radiation drying, resulting in a uniform negative electrode sheet.

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Silicon-based negative electrode materials for lithium-ion batteries that achieve high energy density while maintaining excellent cycling stability. The materials comprise silicon alloys with specific compositions, including ferrosilicon, silicon-aluminum, silicon-nickel, and ferro-silicon-aluminum. These alloys exhibit superior capacity retention and volumetric efficiency compared to conventional graphite-based materials, enabling higher energy density batteries. The alloys' unique properties, including enhanced surface reactivity and reduced SEI thickness, enable the development of negative electrodes with improved performance characteristics.

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Active material layer for negative electrodes in lithium-ion batteries with improved cycle stability and capacity retention. The layer contains carbon particles and silicon-based particles that can occlude and release lithium ions, combined with a polyimide-based binder. The layer achieves a porosity of 42% or more, enabling both high capacity and excellent cycle characteristics. The binder is specifically optimized for this application, with controlled imide bond formation and molecular weight distribution.

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Active material layer for negative electrodes in lithium-ion batteries that combines high charge/discharge capacity with excellent cycle characteristics. The layer contains silicon-based particles that can store and release lithium ions, combined with a polyimide-based binder with a porosity of less than 20%. This material structure enables both high capacity and cycle stability, while maintaining the conventional characteristics of negative electrodes.

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Aqueous-based polymer binder system for fabricating silicon-based anode materials that enables high-performance lithium-ion batteries while addressing the challenges of traditional anode materials. The binder system comprises a water-soluble polymer matrix with additives and modifiers that enhance its mechanical properties, thermal stability, and electrical conductivity. The system enables the fabrication of high-capacity silicon-based anode materials with improved cycle life, reduced capacity fade, and enhanced interfacial compatibility with the current collector.

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High performance lithium ion batteries with improved electrodes and methods of making them. The batteries have specific capacities, voltage windows, and cycle life improvements over conventional lithium ion batteries. The key innovation is prelithiating the negative electrode (anode) with excess lithium before cell assembly. This compensates for lithium loss during cycling and allows higher state of charge of the anode for specific energy gain. The prelithiated anode has a lithium occupancy fraction above 10%. The prelithiated anode and positive electrode have a N/P ratio above 1. This enables lower voltage operation below 5V. The prelithiation process involves adding lithium based on parameters like capacity, cycle efficiency, and initial charge level.

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Polyimide binder for lithium-ion batteries with improved cycle stability and energy density. The binder combines tetrabutyl titanate and cyclodextrin with aromatic ditincture monomers and diamines, forming a uniform slurry. The slurry is applied to silicon-based anode materials, coated onto current collector surfaces, and then cured through imidization. This binder system addresses the volume expansion issues of silicon-based anodes while maintaining excellent adhesion and performance.

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A method for lithiating metal anodes in lithium-ion batteries by forming lithium-ion conductive electrodes through controlled pressure processing of electroactive materials. The process involves treating an electroactive material with a first electrolyte to form a pretreated material, followed by applying pressure to the pretreated material in conjunction with a lithium source to form a lithiated material. The lithiated material is then integrated into the battery cell as a negative electrode. The pressure application enables efficient lithium-ion transfer while maintaining material integrity, enabling improved battery performance and reduced capacity loss.

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Lithium-ion battery with high energy density, fast charging capability, and cold temperature performance. The battery uses a negative electrode of phosphorene, a positive electrode with a lithium iron orthosilicate (Li2FeSiO4) transition during charging, and an organic electrolyte. The phosphorene negative electrode provides high current density for fast charging. The Li2FeSiO4 positive electrode allows high energy density without cobalt. The organic electrolyte enables charging at low temperatures. This battery design enables high energy, fast charging, and cold temperature performance for electric vehicles.

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A method for preparing lithium-ion battery negative electrode materials that addresses the safety issue of lithium dendrite formation during charging and discharging. The method involves incorporating cyclodextrin into the electrode preparation process, where cyclodextrin forms pores that create rich lithium ion binding sites while enhancing ion diffusion channels. This approach enables the material to maintain structural integrity and stability during repeated charge/discharge cycles, while still achieving high lithium ion storage capacity and rapid charging capabilities.

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A method for pre-lithiating silicon-containing lithium-ion battery electrodes that enables high-capacity anodes with improved electrochemical performance compared to conventional materials. The method involves reacting lithium hydride with silicon-containing compounds to form pre-lithiated materials, which are then used to prepare electrode structures. The pre-lithiated materials contain silicon, lithium, and other elements, and can be formed through various methods including heating with inert gases and mechanical alloying. These pre-lithiated materials can be directly integrated into electrode structures to prepare negative electrodes for lithium-ion batteries, offering enhanced performance characteristics and reduced material costs.

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Lithium metal battery with improved performance through a novel negative electrode design. The battery features a negative electrode comprising a lithium metal anode with a specific coating thickness range. The coating thickness is precisely controlled to prevent excessive lithium depletion while maintaining sufficient SEI film formation. This controlled thickness enables optimal lithium utilization during charge and discharge cycles, while preventing dendrite growth and maintaining battery stability.

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High-performance lithium-ion battery electrodes that achieve superior performance through localized pyrolysis of polymer matrices. The electrodes combine a conductive current collector with a pyrolyzed carbon matrix containing silicon, which enables controlled expansion and contraction during lithium insertion/extraction. The pyrolysis process creates a gradient in the polymer matrix composition, allowing precise control over the material properties. This approach eliminates the conventional interface damage associated with traditional electrode fabrication methods, resulting in enhanced electrochemical performance and reduced capacity fade.

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A novel SiO/C/Cu composite material for lithium-ion batteries that addresses the challenges of silicon anode degradation through improved conductivity, structural stability, and cycle performance. The material is prepared through a novel hydrothermal synthesis process followed by Cu layer deposition, resulting in a SiO/C/Cu composite with enhanced electrical conductivity, structural integrity, and reversible lithium insertion properties. This composite material enables high-capacity, long-cycle performance in lithium-ion batteries while maintaining superior cycle life compared to conventional silicon anodes.

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A lithium-ion battery electrolyte that enhances thermal stability and electrical conductivity while maintaining safety. The electrolyte contains a novel combination of additives with specific functional groups, including -CN and P-Ο bonds. These functional groups enable enhanced thermal management through specific interactions with the electrolyte's thermal expansion properties, while maintaining electrical conductivity. The electrolyte's composition provides superior performance at both elevated temperatures and in high-drain applications.

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Lithium-ion batteries with enhanced anode performance through controlled partial lithiation. The battery comprises a cathode, an anode comprising silicon particles, a separator, and an electrolyte. The anode material in the fully charged battery is only partly lithiated, with the maximum lithium uptake capacity corresponding to 4.4 lithium atoms per silicon atom. This partial lithiation maintains reversible capacity while preventing significant volume expansion during charging and discharging. The battery achieves stable capacity retention through the formation of stable solid electrolyte interfaces (SEIs) and controlled passivation layers.

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Pre-lithiation of lithium-ion battery negative electrodes through controlled external short circuits before charge insertion. The method involves establishing an external short circuit between the positive and negative electrodes of a coin cell before charge insertion. This controlled short circuit prevents the formation of a solid polymer electrolyte membrane during the first charge, thereby reducing the irreversible lithium consumption typically associated with this process. The short circuit can be achieved through various methods, including using external electrodes or creating a temporary connection between the electrodes. This approach enables the battery to operate with a fully lithiated negative electrode surface before the first charge, significantly improving the battery's first-cycle Coulombic efficiency.

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