Transforming EV Safety with Electrode Material Innovations

Binder-free, self-supporting electrodes for rechargeable batteries that can be easily regenerated and reused without disassembly. The electrodes have active materials like cryptomelane-type manganese dioxide (OMS-2) that form fibrous nanostructures without binders or current collectors. These self-supporting electrodes can be thermally regenerated by heating under air to restore capacity after cycling. The regenerated electrodes can then be put back in the battery or a new one. The lack of binders allows the active materials to be self-supporting and regenerated without disassembly.

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Lithium battery anodes with reduced dendrite growth and improved cycling stability through using a porous matrix as a host for the lithium metal. The matrix provides a stable structure that reduces the volume change during cycling compared to pure lithium foil. The matrix also has high surface area for uniform lithium deposition. This prevents dendrites and improves cycling performance. The matrix can be made of materials like graphene, nanotubes, or mesoporous carbon. The lithium infuses into the matrix during preparation and during cycling. This provides a composite anode with reduced dimension change, dendrite suppression, stable electrode interface, and uniform lithium deposition.

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Battery cell thermal management using optimized heat conducting members to improve performance and lifespan. The heat conducting members are customized for each battery cell based on the electrode heat generation profile. They have a thermally insulating portion and a thermally conducting portion with a morphology like dendritic or lamellar. This optimized morphology matches the electrode heat generation for better heat transfer. The customized heat conducting members positioned between the electrodes conduct heat away from the cell and transport it to external systems for removal. This tailored thermal management extends battery life and efficiency compared to generic cooling systems.

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Electricity storage device, such as a rechargeable battery, with an electrode assembly configuration that reduces short circuit heat generation when the electrodes contact due to separator contraction during temperature changes. The electrode assembly has overlapping electrodes with sections free of active material at the ends. The separators have strong bonding sections near the free-end sections and weaker bonding sections near the active material sections. This allows the separators to contract and move apart at the active material sections to prevent shorting, while the strong sections at the free-end sections hold the electrodes together and prevent separation.

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Lithium ion battery cells with improved performance, safety, and longevity for electric vehicles. The battery cells have a core wrapped in a rectangular shell with gaskets to prevent contact between the core and end caps. This prevents short circuits. The core can have coiled electrode layers for high power density. The electrode materials are mixed crystal lithium iron phosphate with additional metal oxides for better cycling. The gaskets compress the core away from the caps to prevent internal hotspots. The rectangular shape reduces stress concentrations compared to cylindrical cells. The improved cell design prevents failures like internal shorts, hotspots, and thermal runaway.

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A mixed positive electrode material for lithium-ion batteries that improves both output voltage and cycle life at high temperatures. The material is a composite of two types of positive electrode active materials with different particle sizes. The composite contains a large-grain material with 10 μm or greater average diameter and a small-grain material with 5 μm or less average diameter. The two materials are separately coated with different materials between lithium triborate (or lithium boran oxide) and metal oxide. This coating composition allows high voltage operation while maintaining stability at elevated temperatures.

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Carbon-coated electrode materials for lithium-ion batteries with improved performance and cycle life compared to uncoated materials. The carbon coating is applied using an electrochemical process. The carbon coating protects the active material particles during cycling, reducing capacity fade and improving cycle life. The coating is amorphous carbon with a D/G ratio of 2-3.5 as determined by Raman spectroscopy. The carbon coated particles can be used in lithium-ion battery electrodes, with potential benefits in applications like electric vehicles. The carbon coating also provides a buffer layer to reduce volume changes during cycling, further improving cycle life.

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A high-performance anode for lithium and sodium metal secondary batteries that suppresses dendrite formation and improves cycle life without using expensive solid electrolytes or ceramic separators. The anode is a 3D graphene-carbon hybrid foam electrode that provides a stable and dendrite-free lithium or sodium anode. The foam electrode is made by converting graphene oxide to graphene using a simple, scalable process. The graphene is mixed with carbon and a metal like nickel to create the foam. The metal promotes lithium or sodium adsorption and prevents dendrites. The foam structure provides mechanical stability and electrical conductivity.

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Anode material for lithium-ion batteries with improved cycling performance and high rate capability. The anode uses lithium titanate (LTO) particles with a cross-linked phosphate coating. The coating is formed by impregnating the LTO with a phosphate solution and curing. The cross-linked phosphate coating on the LTO particles retains the porous structure between the particles, maintaining high electrode porosity for good ionic conductivity. The phosphate coating also improves cycle life and rate performance compared to uncoated LTO.

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A method to manufacture lithium battery positive electrode materials with a concentration gradient that improves stability and cycling life compared to conventional materials. The method involves coating the core particle with a barrier layer to prevent diffusion of transition metals during subsequent thermal treatment. This prevents degradation at high temperatures while still allowing a continuous concentration gradient between the core and outer shell layers. The barrier layer prevents sharp compositional boundaries and interfaces that can cause defects and instability.

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Carbon material for high-performance lithium-ion battery electrodes that provides good electrode filling, high energy density, and high charge/discharge cycle performance. The carbon material has a specific particle shape, size, and surface chemistry. It involves graphitizing coke at high temperatures and then oxidizing the graphite at intermediate temperatures. This process removes surface impurities, improves cycling stability, and enhances initial coulomb efficiency. The carbon particles have an average size of 1-30 µm, circularity of 0.80-0.95, and a low surface area. The oxidation step removes active edge sites and prevents electrolyte decomposition. This allows high-rate charging/discharging and cycle life.

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Lithium cell with improved separator for lithium ion batteries that addresses issues like dendrite growth and electrolyte degradation. The separator is a gel containing fibers that are wettable by the electrolyte and have a high surface tension. The fibers prevent electrode shorting while allowing ion transfer. The wettable fibers reduce electrolyte degradation compared to non-wettable separators like polyethylene. The fibers also prevent dendrite growth as they provide a barrier against lithium metal deposition on the anode. The separator gel can also have a matrix with the electrolyte solution.

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Lithium-sulfur battery with enhanced performance using a yoke-shell nanoparticle design. The battery electrode contains nanoparticles with a decomposable sulfur core surrounded by a permeable organic polymer shell. During charge/discharge, the sulfur decomposes into polysulfides. The shell confines the expanding polysulfides and prevents shuttling. The void space between the yoke and shell accommodates expansion. This mitigates the volume change issue in lithium-sulfur batteries.

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Lithium-sulfur battery positive electrode design that improves performance and capacity by ensuring even sulfur coverage and electrolyte access during cycling. The electrode structure has carbon nanotubes grown vertically from the current collector. The density of nanotubes is kept low, around 40 mg/cm3, to allow sulfur impregnation. The nanotubes have bent shapes with heights of 0.4-0.8 times their length. This increases surface area for sulfur adsorption. The nanotube shape and density ensure complete sulfur coverage down to the base end, preventing gaps. The bent shape also prevents sulfur elution during cycling.

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Battery with improved safety and performance by using flat shaped particles with high aspect ratio that can undergo endothermic dehydration reactions. The particles are added to the battery electrolyte between the electrodes. When the battery heats up, the particles absorb energy by dehydrating without generating gas or decomposing. This prevents internal shorts and thermal runaway. The particles have aspect ratios of 2:1 or higher, where the length is 2 times the width.

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Nonaqueous electrolyte secondary battery with improved cycling performance and reduced corrosion of aluminum current collectors in high-voltage environments. The battery uses an electrolyte solution containing a salt with a cation like lithium, fluorine, or aluminum, and an organic solvent with a heteroelement like carbon, sulfur, or fluorine. The electrolyte composition satisfies a condition where the intensity of peaks in vibrational spectroscopy due to the solvent is greater than the intensity of peaks due to the solvent without the salt. This electrolyte formulation improves cycling stability, reduces corrosion of aluminum electrodes, and has high viscosity for better liquid retention at the electrode interface.

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Thin film electrodes for lithium-ion batteries with improved cycling stability and capacity retention compared to conventional thin film electrodes. The thin films have density gradients where the density decreases with distance from the surface. This is achieved by controlling the gas pressure during deposition based on the thickness. The density modulation prevents delamination and cracking during cycling. The graded density allows thicker films with better stability than uniform density films. The graded density also reduces stress during lithiation/delithiation. The thicker films with improved cycling properties are needed for practical batteries.

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Lithium battery anode with improved cycle life and capacity compared to conventional graphite anodes. The anode comprises a metal film inert to lithium ions coated on a silicon wafer with embedded silicon nanowires protruding from the film. The nanowires are anchored inside the metal film rather than just adhered to the surface. This prevents nanowire detachment during cycling due to volume expansion, reducing capacity fade. The metal film encapsulates the nanowires, preventing lithium from penetrating the silicon wafer. This allows high capacity utilization without degradation. The nanowire embedding technique is achieved by electrodepositing metal on a nanowire-etched silicon wafer.

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A method for manufacturing lithium-ion battery negative electrodes with improved cycle life and reduced resistance degradation. The method involves using a binder containing a polyimide, polyamide-imide, or polyamide, and then thermally curing the binder directly on the negative electrode collector using a hot-roll press. This step is performed after coating the slurry on the collector and before drying. The collector and slurry are heated to 150-300°C during the press. This allows the binder to cure and form a uniform layer without separating from the collector, preventing resistance increases during cycling.

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Negative electrode material for lithium-ion batteries that improves cycling life by coating lithium silicate particles with a carbonaceous substance. The coating process involves selecting a carbon-containing compound that is solid at room temperature and has a zeta potential of 60 mV or higher in NMP. Heating the compound at temperatures between its decomposition point and 1100°C forms a carbon coating on the lithium silicate particles. This carbon coating helps buffer the particles during cycling to reduce capacity fade.

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