Electrode/electrolyte interfacial engineering for aqueous Zn-ion batteries

Aqueous Zn-ion batteries (AZIBs) hold great promise for large-scale energy storage applications due to their low cost, intrinsic safety, and high theoretical capacity. However, the delivery of stable electrode–electrolyte interface becomes the main challenge for developing high-performance AZIBs with long cycle life and high capacity. On the cathode side, the dissolution of active materials, formation of byproducts, and unsatisfactory interfacial compatibility frequently occur. Meanwhile, the Zn metal anodes usually suffer from inevitable Zn dendrites and parasitic reactions. Both the electrode–electrolyte interface issues for the cathodes and anodes will finally result in poor electrochemistry reversibility and fast capacity decay. With this perspective, this review focuses on the key scientific issues occurred at the electrode interfaces, and also proposes corresponding interfacial optimization strategies, including surface modification and electrolyte optimization, aiming at providing guidelines for the design of high-performance AZIBs based on the understanding of interface improvement and practical application considerations.