Enhanced cyclability of silicon anode via synergy effect of polyimide binder and conductive polyacrylonitrile

Abstract

The damage of electrode integrity resulting from large volume change during cycling is the main reason that leads to the fast capacity loss of silicon anodes. Consequently, developing silicon anodes with integrated structure is critical for their practical application. Here, an integrated silicon anode with enhanced cycling ability using polyimide as binder and cyclized polyacrylonitrile as conductive matrix is fabricated by a facile pyrolysis process. The imidization of polyimide and cyclization of polyacrylonitrile are conducted simultaneously during the in situ heat treatment process. Owing to the synergy effect of polyimide binder and conductive polyacrylonitrile which can restrict volume expansion and maintain integrated conducting path effectively, the electrode exhibits a higher initial coulombic efficiency of 83.6% and delivers excellent cycle life with a high reversible capacity of 2362.2 mAh g−1 even after 100 cycles at a current density of 0.1 C, revealing significant improvement in cycle life in comparison with that of Si@cPAN or PI electrode.