β-Hydrogen of Polythiophene Induced Aluminum Ion Storage for High-Performance Al-Polythiophene Batteries

The urgent need for large-scale, low-cost energy storage has driven a new wave of research focusing on innovative batteries. Due to the high capacity and the low-cost of elemental Al, aluminum-ion batteries (AIBs) are expected as promising candidates for future energy storage. However, further development of AIBs is restricted by the performance of existing carbon-based cathodes and metal chalcogenide cathode materials. In this work, we deposited polythiophene (Pth) on a graphene oxide (Pth@GO) composite and used it as an AIB cathode material. This Pth@GO composite possesses high exposure of Pth active sites, high conductivity, and high structure stability while providing a very high discharge capacity (up to 130 mAh g^-1) and outstanding cyclic stability (maintaining above 100 mAh g^-1 after 4000 cycles). First principles calculations and experimental results show that the charge is stored on Pth@GO through an electrostatic attraction between AlCl₄^- and β-hydrogen (C_β-H) sites in polythiophene.