▎ 摘　　要

NOVELTY - Preparation of tin dioxide/nitrogen-doped graphene composite cathode material comprises preparing graphene oxide solution by modified Hummer method, mixing nitrogen source and graphene oxide solution, carrying out first hydrothermal reaction to prepare three-dimensional nitrogen-doped graphene sponge, soaking nitrogen-doped graphene sponge in deionized water for 1-24 hours, taking out into the reactor, dropwisely adding precursor solution, carrying out secondary hydrothermal reaction, compounding three-dimensional nitrogen-doped graphene with tin dioxide, soaking in deionized water or washing, cooling, drying using liquid nitrogen, freeze-drying and calcining in inert atmosphere. USE - Method for preparing tin dioxide/nitrogen-doped graphene composite cathode material used for high-capacity lithium ion battery (claimed). ADVANTAGE - The product has good multiple extraction and excellent circulation performance, very high specific capacity, improved electronic and lithium ion transmission efficiency to construct more electron and ion transmission channel and good electrochemical performance.