A metal-free porphyrin (TDPP) with a diphenylamino-Phenyl group is proposed as an electrode for aluminum-based batteries. The electrochemical performance is explored thoroughly. The extended porphyrin conjugated structure by the diphenylamino-phenyl groups shows a reversible capacity of 83 mAh g⁻¹ at 1 A g⁻¹ after 200 cycles and good cycling stability.

Abstract

Nowadays, Al (dual) batteries are mainly based on graphite cathode materials. Besides this material, the limited life cycle and the rate performance of other possible cathode materials have hampered the development of practical and sustainable rechargeable aluminium batteries (RABs). Herein, we report an organic A₄-metal-free porphyrin system bearing diphenylamimo-phenyl functional units as an Al-storage cathode material, which is capable of delivering a reversible capacity of 83 mAh g⁻¹ at 1 A g⁻¹ after 200 cycles and displays a good cycling stability. Achieving such high rate performance opens a pathway to developing practical sustainable cathodes for aluminium batteries.