Multi-interface optimization induced by aniline electrolyte additive toward long-life aqueous zinc ion batteries

The application of aqueous zinc ion batteries still faces severe challenges, including Zn dendrites formation, side reactions, and instability of cathode materials. In this study, a multi-interface optimization strategy using aniline (ANI) as an electrolyte additive is proposed to solve these problems simultaneously. Ultrathin polymer layers can be formed on the surfaces of electrodes and separator owing to the in-situ polymerization of ANI. Thus, the structural stability of the anode, separator and cathode can be improved due to alleviated side reactions and enhanced interfacial protection of electrodes and separator. The strong interaction between Zn 2+ and ANI can distribute the Zn 2+ flux well and promote the de-solvation process, resulting in more even Zn deposition. With the ANI additive, Zn//Zn symmetric cells can work for more than 1200 h, and more than 400 h even at higher current densities and plating capacities (10 mA cm −2 , 10 mA h cm −2 ). The excellent cycling stability of Na 3 V 2 (PO 4 ) 3 //Zn coin and pouch cells verified the feasibility of using ANI as an additive for performance improvement. As a simple electrolyte additive strategy, multifunctional ANI can realize multi-interface modification effects for electrodes and separator, which is expected to provide a viable solution for the commercialization of long-life AZIBs.