Synergistic Effect of Anodic Hydrophilic and Hydrophobic Interfaces for Long Cycle Life Aqueous Aluminum–Zinc Hybrid Ion Batteries

Abstract Aqueous aluminum ion batteries (AAIBs) have drawn considerable attention due to their intrinsic safety, cost‐effectiveness, eco‐friendliness, and high theoretical capacity of aluminum. Currently, suitable anode materials are crucial for the development of high‐performance AAIBs. For the first time, a hydrophilic (ZnCr 2 O 4 ) and hydrophobic (PVDF) layer modified zinc anode paired with an aluminum‐based aqueous electrolyte to construct a high‐performance aluminum–zinc hybrid ion battery. The Hydrophilic ZnCr 2 O 4 layer of anode endows the battery with low polarization by boosting the pre‐desolvation and deposition kinetics of aluminum/zinc ions. Meanwhile, the hydrophobic PVDF layer suppresses water‐induced corrosion of the anode. The synergistic effect of the hydrophilic and hydrophobic layers of the anode stimulates the battery to exhibit unprecedented cycle life (> 6000 cycles) and considerable discharge capacity (280 mAh g −1 ), compared to the batteries proposed in previous works paired with aluminum alloy anodes and aluminum‐based aqueous electrolytes. This novel anode provides powerful backing for the development of long‐life and high‐capacity aqueous polyvalent ion batteries due to its low cost and simple fabrication process.