Silicon-Graphene Nanocomposite Anode for Lithium-Ion Batteries

The patent embeds silicon particles within a three-dimensional conductive carbon matrix structure, creating a nested configuration where silicon is contained within the carbon framework. This nesting approach allows the silicon to expand and contract during lithium cycling while being supported by the surrounding carbon matrix, preventing pulverization and maintaining structural integrity over multiple cycles.

The patent creates a composite material system combining silicon particles with conductive carbon materials (such as graphene, carbon nanotubes, or graphitic carbon). This composite structure leverages the high capacity of silicon while the carbon component provides mechanical strength, electrical conductivity, and structural stability, resolving the contradiction between achieving high energy density and maintaining cycle life.

The patent optimizes key parameters including the size distribution of silicon particles, the ratio of silicon to carbon materials, the pore size and distribution in the carbon matrix, and the density of the three-dimensional structure. By carefully controlling these parameters, the patent achieves high cycle life performance while using commercially available materials and processes, avoiding the need for expensive exotic synthesis methods.

The patent creates regions with different properties within the carbon matrix, including conductive pathways, porous regions for electrolyte access, and structural support zones. This local differentiation of quality allows the material to simultaneously achieve good electrical conductivity, efficient lithium ion transport, and mechanical strength, improving cycle life without requiring uniform expensive materials throughout the entire structure.