▎ 摘　　要

NOVELTY - The preparation of silicon dioxide/graphene nano composite material, involves dispersing graphite oxide in water to obtain graphene oxide solution, adding sulfuric acid to the solution, ultrasonically dispersing to obtain mixture, transferring mixture to reaction vessel, reacting, washing to obtain three-dimensional columnar reduced graphene oxide, adding silicon-containing compound to solvent to prepare solution, soaking three-dimensional columnar reduced graphene oxide in above solution, transferring to hydrothermal reactor, reacting, washing and drying. USE - Preparation of silicon dioxide/graphene nano composite material used as cathode of lithium ion battery (all claimed). DETAILED DESCRIPTION - The preparation of silicon dioxide/graphene nano composite material, involves dispersing graphite oxide in water to obtain graphene oxide solution, adding sulfuric acid to the solution, ultrasonically dispersing to obtain mixture, transferring the mixture to a reaction vessel, reacting at 160-260 degrees C preferably 190-220 degrees C for 18-30 hours preferably 20-24 hours, taking out, washing to obtain three-dimensional columnar reduced graphene oxide, adding silicon-containing compound to the solvent to prepare solution, soaking three-dimensional columnar reduced graphene oxide in above solution at 3-30 degrees C preferably 5-20 degrees C for more than 1 day preferably 2-3 days, transferring to hydrothermal reactor, reacting at 120-180 degrees C preferably 150-180 degrees C for 18-36 hours preferably 20-24 hours, washing and drying. INDEPENDENT CLAIMS are included for the following: (1) cathode of lithium ion battery; and (2) lithium ion battery.