CoO Hollow Cube/Reduced Graphene Oxide Composites with Enhanced Lithium Storage Capability

Abstract

Hollow hierarchical CoO nanocube/reduced graphene oxide (COG) composite has been fabricated with the sacrificial-template method and the subsequent thermal treatment. Hollow/porous architectures supply high specific surface area and buffer the volume change during the lithium uptake/release processes, while rGO matrix ensures the system conductivity and further reinforces the structure. Serving as the anode material of lithium ion battery, COG demonstrates high lithium storage capacity, reaching 1170 mA h g–1 at a current density of 150 mA g–1, which is much higher than the capacity of rGO-free hollow CoO nanocubes. Ninety-four percent retention after 60 cycles further proves its stable cyclability. The combination of the advantages of the as-prepared befitting nanostructure and the rGO should be responsible for the durable rate behavior and the high capacity. Moreover, unfully reduced graphene oxide was achieved with the assistance of the multifunctional Na2S2O3, leading to more disorders and defects left in the composite and should also afford a positive influence on the lithium storage performance of the COG.