Construction of Cu-doped Co3O4/rGO composites with a typical buffer structure for high-performance lithium storage

Abstract

Transition metal oxides (TMOs) are considered to be an ideal anode material for the high performance lithium-ion batteries (LIBs). However, their inferior conductivity of electrons and ions, in addition violently volume change enable the significant capacity plunge. Here, the TMOs nanoparticles were encapsulated in a reduced graphene oxide (rGO) by an easy grinding strategy to solve the above problems. The rGO encapsulated Cu-doped Co3O4 (CCO) composite electrode was fabricated by combining a handy sol-gel and grinding way. As anode material of LIBs, the CCO/rGO composites are provided with favorable specific capacity (2093 mAh g−1 at 4 A g−1), superior rate capability (1949 mAh g−1 at 5.0 A g−1) and good cycling stability. The flexible rGO enables the excellent lithium storage performance, which effectively prevents the nanoparticles aggregating to provide more storage lithium active sites. The structure of nanoparticles is preserved during the cycling process to enhance the conductivity. In this paper, a universal and efficient method is accomplished, which builds an original dual metal oxide wrapped in rGO applied to energy storage.