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 (Cβ–H) sites in polythiophene.