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

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>In this paper, an anode material system of Co<SUB>3</SUB>O<SUB>4</SUB> nanowires composited with reduced graphene oxide (Co<SUB>3</SUB>O<SUB>4</SUB> NWs/rGO) and protected by N-doped carbon layer (Co<SUB>3</SUB>O<SUB>4</SUB> 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 Co<SUB>3</SUB>O<SUB>4</SUB> NWs/rGO during repeated charge/discharge cycles, and also enhance the reaction kinetics as a highly conductive layer between the Co<SUB>3</SUB>O<SUB>4</SUB> NWs and electrolyte. The Co<SUB>3</SUB>O<SUB>4</SUB> NWs/rGO@NC electrode delivered a high discharge capacity of ca. 995 mAh g<SUP>−1</SUP> at 0.1 C after 65 cycles, and showed a much better rate performance of 428 mAh g<SUP>−1</SUP> even at a high current rate of 5 C as compared to those of Co<SUB>3</SUB>O<SUB>4</SUB> NWs/rGO electrode (203 mAh g<SUP>−1</SUP>). The demonstrated electrochemical properties suggested that the N-doped carbon coating on the composite of Co<SUB>3</SUB>O<SUB>4</SUB> NWs and rGO could significantly enhance the durability and rate capability of the anode material for high performance lithium ion batteries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nitrogen atoms were reacted with defects of carbon material and doped in the lattice. </LI> <LI> N-doped carbon layer enhances the reaction kinetics between the Co<SUB>3</SUB>O<SUB>4</SUB> NWs and electrolyte. </LI> <LI> N-doped carbon coating could significantly enhance the durability and rate capability. </LI> </UL> </P>