Anode‐Free Aqueous Aluminum Ion Batteries
Cheng Lu, Fangfang Zhao, Bowen Tao, Zhilong Wang, Ying Wang, Jiaping Sheng, Gen Tang, Yue Wang, Xiang Guo, Jinjin Li, Liangming Wei
Abstract
Abstract Aqueous aluminum ion batteries (AAIBs) possess the advantages of high safety, cost‐effectiveness, eco‐friendliness and high theoretical capacity. However, the Al 2 O 3 film on the Al anode surface, a natural physical barrier to the plating of hydrated aluminum ions, is a key factor in the decomposition of the aqueous electrolyte and the severe hydrogen precipitation reaction. To circumvent the obnoxious Al anode, a proof‐of‐concept of an anode‐free AAIB is first proposed, in which Al 2 TiO 5 , as a cathode pre‐aluminum additive (Al source), can replenish Al loss by over cycling. The Al‐Cu alloy layer, formed by plating Al on the Cu foil surface during the charge process, possesses a reversible electrochemical property and is paired with a polyaniline (cathode) to stimulate the battery to exhibit high initial discharge capacity (175 mAh g −1 ), high power density (≈410 Wh L −1 ) and ultra‐long cycle life (4000 cycles) with the capacity retention of ≈60% after 1000 cycles. This work will act as a primer to ignite the enormous prospective researches on the anode‐free aqueous Al ion batteries.