Preparation and Electrochemical Properties of PSi@PEDOT/GO as an Anode Material for Li-Ion Batteries

Abstract

The high energy density of Si makes it a preferred anode material for lithium-ion batteries. However, the low conductivity and large volume changes associated with the charging and discharging processes lead to a rapid decay in capacity during cycling, which hinders its commercialization. In this study, micron-scale PSi@PEDOT/GO composites were prepared by coating commercial Al–Si alloys with poly 3,4-ethylenedioxythiophene (PEDOT) and graphene oxide (GO) using in situ polymerization and freeze-drying methods. The core layer of the PSi@PEDOT/GO composite has abundant internal pores to provide sufficient space to adapt to the volume change of silicon, whereas the PEDOT and GO coating layers can accelerate the ion and electron transport and accommodate the volume change of silicon, which can effectively improve the cycling stability and rate performance of the silicon anode. The characterization results show that the PSi@PEDOT/GO-2 (mass ratio = 6:4:5) composite electrode material has a specific capacity of 1102.30 mAh/g after 100 cycles. When the current density is 0.3A/g, the specific capacity is still 1102.30 mAh/g after 100 cycles, and the capacity retention rate is 75.8%. In addition, it exhibits a specific capacity of 406.87 mAh/g at a current density of 4 A/g, indicating excellent cycling and rate performance and good application prospects.