Improving the electrochemical performance of Si anode by using N-doped carbon materials in lithium-ion batteries

Silicon anode has drawn much attention due to its high specific capacity and energy density. However, the silicon anode also faced with some problems, including poor electronic conductivity and huge volume expansion during the electrochemical cycles. All of these problems will cause rapid capacity fading with the increase of the cycle numbers. Therefore, it is urgent to deal with these issues via designing Si-based composite materials. Herein, the N-doped carbon/silicon composites (NC@Si) were successfully prepared and used as anode materials in the lithium-ion batteries. Owing to the presence of the N-doped carbon materials, the electronic conductivity could be greatly improved. Moreover, the volume change could be inhibited due to the carbon framework during the electrochemical cycles. As a result, the as-prepared NC@Si composite anode shows high capacity of 3368 mAh/g. In addition, it delivered stable cycling performance with high capacity retention with the increase of the cycle numbers.