▎ 摘　　要

NOVELTY - Graphene-silicon airgel composite comprises silicon nanoparticles surrounded by reduced graphene oxide which is three-dimensionally connected and has porous structure; and spherical composite dispersed in reduced graphene oxide. USE - Graphene-silicon airgel composite used as negative active material in lithium secondary battery (all claimed). ADVANTAGE - The graphene-silicon airgel composite helps in improving energy density and velocity characteristics, and volume changes caused by insertion/departure of lithium ions; have high specific surface area, reduces solid-phase diffusion path and increases interface between positive electrode-separator-cathode; enables high-rate discharge characteristics and high-power lithium-ion batteries. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for manufacturing graphene-silicon airgel composite, which involves spray-drying first solution, which contains first graphene oxide, and silicon nanoparticles; heat-treating, and reducing spray-dried material to obtain spherical composite; reducing spherical composite, second graphene oxide, and gelling second solution; and freeze-drying reduced, and gelled second solution to obtain porous airgel composite, which includes graphene/silicon, which have three-dimensional structure; (2) a negative active material, which comprises graphene-silicon airgel composite; and (3) a lithium secondary battery, which comprises negative electrode, which further comprises negative active material, and electrolyte.