High‐Energy‐Density Quinone‐Based Electrodes with [Al(OTF)]2+ Storage Mechanism for Rechargeable Aqueous Aluminum Batteries

Abstract Rechargeable aqueous aluminum batteries (AABs) are potential candidates for future large‐scale energy storage due to their large capacity and the high abundance of aluminum. However, AABs face the challenges of inferior rate capability and cycling life due to the high charge density of Al 3+ , which induces the sluggish intercalation/extraction dynamics and structure collapse of inorganic cathode materials during discharge–charge cycles. Here, the optimization of macrocyclic calix[4]quinone (C4Q) with a large cavity and multi‐adjacent carbonyls structure from quinone compounds to become excellent cathode materials for high‐energy‐density AABs is reported. It exhibits a high capacity of 400 mAh g −1 , a high rate capability (300 mAh g −1 at 800 mA g −1 ), and an excellent low‐temperature performance (224 mAh g −1 at − 20 ° C). The combination of experiments and theoretical calculations proves that Al(OTF) 2+ cations coordinate with the carbonyl groups of C4Q during the discharge process, which can reduce desolvation penalty. Moreover, the fabricated pouch‐type Al‐C4Q battery delivers an energy density of 93 Wh kg −1 cell , showing great potential for large‐scale applications. This work is expected to facilitate the application of organic cathode for AABs.