Preparation and electrochemical performance of Lithium-ion battery negative electrode material PSi@GO

The high energy density of silicon makes it one of the preferred materials for the negative electrode of lithium-ion batteries. However, the low conductivity and the accompanying large volume changes during charging and discharging process led to the rapid decay of the capacity during the cycle, which hindered its commercialization. In this paper, a commercialized aluminum-silicon alloy is used as the silicon source, and graphene oxide is coated on the surface by freeze-drying method to prepare micron-scale PSi@GO composite materials. The rich pores inside the porous silicon core layer of the composite material provide sufficient space to accommodate the volume changes of silicon, and the graphene oxide in the outer composite layer can accelerate the transmission of ions and electrons and buffer the volume change of silicon again, thereby effectively improving the cycle stability and multiplier performance of the silicon negative electrode. The research results show that when the PSi@GO-2 (with a mass ratio of 10∶5) composite electrode material has a current density of 500 mAh/g, the specific capacity is still 1 290.60 mAh/g after 100 cycles. In addition, it still has a high specific capacity of 979.78 mAh/g when the current density is 4 A/g. The PSi@GO composite material shows excellent multiplier performance and has good application prospects.