Studies on the preparation and electrochemical performance of PSi@Poly(3, 4-ethylenedioxythiophene) composites as anode materials for lithium-ion batteries

Porous silicon (PSi) has become one of the current hotspots in lithium-ion anode materials research. However, due to their large volume change in the charge and discharge processes, which results in poor electrochemical performance, the material’s practical value is significantly impacted. In this study, PSi@poly(3,4-ethylenedioxythiophene) (PSi@PEDOT) composites were prepared by coating porous micron Si etched from the commercial Al–Si alloy with a conductive polymer synthesized via the in situ polymerization of 3,4-ethylenedioxythiophene (EDOT). The PEDOT shell not only ensures the conductive network in the composite material but also inhibits Si volume expansion. In addition, the pores inside the PSi material’s core layer provide space gaps to buffer Si volume expansion, which can effectively improve its cycling stability and rate performance. Electrochemical test results show that the PSi@PEDOT-2 composite with mass ratio of 1.5:1 exhibits the best cycling stability. The initial discharge capacity is 1338.62 mAh g −1 at a current density of 0.5 A g −1 , and the postcapacity retention rate is 70.3% after 200 cycles. Further, the preparation method may be used as an approach for preparing high-performance Si-based anode materials.