Effect of N-doped carbon layer on Co3O4 nanowire-graphene composites as anode materials for lithium ion batteries

In this paper, an anode material system of Co3O4 nanowires composited with reduced graphene oxide (Co3O4 NWs/rGO) and protected by N-doped carbon layer (Co3O4 NWs/rGO@NC) was prepared for lithium ion batteries. The N-doped carbon layer could serve as stress relief matter to reduce volume changes of the Co3O4 NWs/rGO during repeated charge/discharge cycles, and also enhance the reaction kinetics as a highly conductive layer between the Co3O4 NWs and electrolyte. The Co3O4 NWs/rGO@NC electrode delivered a high discharge capacity of ca. 995 mAh g−1 at 0.1 C after 65 cycles, and showed a much better rate performance of 428 mAh g−1 even at a high current rate of 5 C as compared to those of Co3O4 NWs/rGO electrode (203 mAh g−1). The demonstrated electrochemical properties suggested that the N-doped carbon coating on the composite of Co3O4 NWs and rGO could significantly enhance the durability and rate capability of the anode material for high performance lithium ion batteries.