High-capacity and small-polarization aluminum organic batteries based on sustainable quinone-based cathodes with Al³⁺ insertion

Benefiting from high-volumetric-specific capacity and superior safety as well as abundant Al source, rechargeable aluminum batteries (ABs) have attracted much attention. However, the lack of cathode materials with the desirable capacity and Al³⁺ insertion/extraction kinetics has severely limited their practical implementation. Herein, we report organic 9,10-anthraquinone (AQ) as Al-storage cathode with favorable Al³⁺ uptake kinetics, which demonstrates a reversible capacity of 215.2 mAh g⁻¹ and good cycling stability. The AQ achieves the reversible uptake/removal of Al³⁺ ions as manifested by a plateau voltage of 1.1 V and a voltage polarization of 0.1 V. Density functional theory (DFT) is performed to reveal the binding site of carbonyl group and the metallic state of Al-inserted configuration, which contribute to fast Al³⁺ diffusion kinetics and high electronic conductivity. This work provides insights and guidance on the design of organic electrodes for the Al-storage performance improvement.