Effects of preparation temperature of graphite oxide on the structure of graphite and electrochemical properties of graphene-based lithium-ion batteries

Abstract

Graphite oxide is synthesized from graphite powder by a modified Hummers method, and the oxidation temperature is controlled in high-temperature oxidation process. By treating graphite oxide powders in a commercial microwave oven, graphene materials can be readily obtained. The morphologies, microstructures, specific surface areas and other features of the graphene and graphite oxide are characterized by FESEM, XPS, XRD and BET. Electrochemical performances of the lithium-ion batteries based on graphene anodes are investigated. The results show that graphene obtained at the oxidation temperature of 90℃ in high-temperature oxidation process actually displays the most remarkable electrochemical performances, that is, the first discharge specific volume and charge capacity of graphene are as high as 1555.5 mAh/g and 1024.6 mAh/g, and after 30 cycles graphene still possess as high as a discharge capacity of 600 mAh/g.