Silicon-graphene composite, method for manufacturing the same, and lithium-ion battery comprising the same

High-capacity silicon anode material using an elastic sponge-graphene shell with internal space to absorb volume expansion

This technology forms a core-shell structure by coating silicon particles with an elastic, 3D porous graphene shell. This structure structurally buffers the volume expansion of silicon during charge and discharge cycles while securing channels for ion and material transport.

Silicon anodes undergo rapid volume expansion during lithiation, which damages the electrode structure and causes the SEI layer to collapse. This leads to inhibited reversible delithiation and rapid depletion of specific capacity.

This technology encapsulates silicon particles within a flower-shaped NiOOH template, grows a 3D porous graphene layer via CVD, and then etches away the nickel to create an elastic "sponge-graphene" structure with a void between the silicon and the graphene. It can be applied to high-energy-density cells for electric vehicles, high-power battery packs for power tools, and silicon-based anodes for mobile devices, helping to increase silicon content while slowing electrode degradation and capacity loss caused by repeated cycling.

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Key Features:

• A 3D porous graphene layer formed on silicon, featuring an elastic structure with a void space between it and the silicon surface.
• A multi-layered, interconnected graphene structure with a thickness of 10 to 50 nm, featuring varied orientations and irregular spacing of 0.1 to 5 nm.
• Pores and channels formed by the random interconnection of multiple graphene nanosheets, providing pathways for material transport.
• A process involving the introduction of silicon particles into a porous nickel compound shell, growing graphene using a carbon source gas, and subsequently removing the nickel.

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