H2‐Inhibited Organic Anodes for Fast and Long‐Life Aqueous Aluminum Ion Batteries with a 3.5‐Month Calendar Life

Abstract Aqueous aluminum ion batteries are rarely constructed due to the unworkable Al metal and the preferential H 2 evolution. Herein, organic anode with H 2 ‐inhibition is optimized through tuning the polymerization degree and displays a high‐rate and reversible storage of Al ions based on an enolation between Al ions and the carbonyl double bonds on the conjugated structures. The superiority of the optimal sample is researched, which is attributed to the raised state of lowest unoccupied molecule orbital (LUMO) with the doner N–N bridge and relatively small steric hindrance of the dimmer. When paired with active carbon, a high cycling life of 5000 cycles with a retention of 99.2% is obtained. A full battery constructed by this dimer and δ‐MnO 2 cathode delivers an average voltage of 1.0 V, high capacity of 263.8 mAh g ‐1 based on the mass of δ‐MnO 2 , and high‐capacity retention of 88.8% after cycling for 300 cycles. More importantly, with a fully eliminated corrosion and passivation in AlCl 3 and Al 2 (SO 4 ) 3 electrolytes, a long calendar stability of 104 days is achieved.