Improving the electrochemical performance of lithium Si batteries by multilayer porous carbon nanosheets/multi-walled carbon nanotubes composite inert nano-Ag

摘要

In this paper, two-dimensional porous carbon nanosheets (PC)/one-dimensional multi-walled carbon nanotubes (MWCNTs) (PM) were used as carbon source supports, and AgNO3 was used as precursor. Si/Ag/PM composite was obtained by water bath reduction and calcination. The loading of nano-Ag improves the conductivity and stability of the Si-based anode. Inert metal nano-Ag can also catalyze the charging and discharging process of nano-Si. The three-dimensional interconnect structure of PM facilitates rapid electrical/ion transport and good electrolyte penetration, exhibits a highly Si-containing layered porous structure, and effectively enhances the physical constraints on soluble polysilicide. In addition, the three-dimensional interconnected layered porous structure and conductive network play a sufficient buffering role, and also help to inhibit the agglomeration of the nano-Ag particles. The lithium storage function of nano-Si is improved. The Initial coulombic efficiency (ICE) of the Si/Ag/PM electrode reached 78.9% at a current density of 0.1 A/g and maintained a specific discharge capacity of 706 mAh/g at a current density of 1 A/g with a capacity retention ratio of 68.6% after 300 cycles.