A high capacity porous Co3O4@graphene composite as lithium battery anode

Among the various anode materials for lithium-ion batteries, Co3O4 is of great interest because of its relatively high specific capacity. Yet, due to its poor electrical conductivity, easy volume expansion leading to rupture and other shortcomings seriously hindered the practical application in the battery. In this work, we prepared Co3O4/graphene (Co3O4/G) composites with three-dimensional porous structure by a simple in situ growth method and by freeze-drying. Due to its unique structure, the graphene layer can inhibit the volume expansion of the Co3O4 reaction to improve its electrical conductivity, while providing more active sites and shorter transport distance, so that more lithium ions can be stored. As anode, the Co3O4/G composite has a specific capacity of 1367.3 mAh g−1 after 80 cycles at 0.1A g−1, and has a specific capacity of 1910.3 mAh g−1 after 300 cycles at 0.5 A g−1. The excellent electrochemical performance provides a reliable reference for future research on the large-scale preparation of high-performance lithium-ion batteries.