Method for manufacturing composite materials using slurry containing reduced graphene oxide

NCM composite cathode material encapsulated with a 3D network of amino-modified rGO and conductive nanoparticles

This technology coats NCM metal oxide surfaces with a composite of amino-modified reduced graphene oxide (rGO) and conductive nanoparticles, such as CNTs, designed to transform 2D graphene sheets into a 3D carbon network structure.

High-nickel NCM cathode materials suffer from low thermal stability and are prone to forming inactive substances when reacting with residual lithium impurities in aqueous media. Conventional carbon coatings often lead to graphene sheet restacking, which hinders lithium-ion transport and fails to adequately prevent surface side reactions.

This technology controls the surface charge of rGO using amino-containing compounds to ensure aqueous dispersibility and incorporates conductive nanoparticles between rGO sheets to form a highly porous 3D carbon encapsulation layer. This layer expands lithium-ion transport paths and protects the active material surface. Applicable to high-nickel cathode coating lines transitioning to aqueous processes and cells for high-power tools and EVs, it enables conductive coating while reducing organic solvent use.

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Key Features:

• Surface-modifying graphene oxide with an amino-containing compound that binds by ring-opening epoxy groups within the graphene oxide
• Concentrating a dispersion containing the surface-modified reduced graphene oxide and conductive nanoparticles to create a slurry
• Combining the slurry dispersion with metal oxide particles and removing the liquid medium to obtain the composite material
• An encapsulation layer 15 to 40 nm thick, where conductive nanoparticles are inserted between rGO sheets to form a 3D carbon network

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This invention was developed with support from the Ministry of Trade, Industry and Energy for charge transfer materials for solution processes in high-efficiency energy components.

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