Construction of stable Zn metal anode by inorganic functional protective layer toward long-life aqueous Zn-ion battery

Aqueous Zinc-ion batteries (AZIBs) have received widespread attention due to their high safety, low cost and environmental friendliness, making them regarded as one of the most prospective energy storage devices. To achieve the commercial application of AZIBs, the design and modification of Zn metal anodes are crucial. Current zinc metal anodes face challenges in terms of battery cycling stability, such as Zn dendrite growth, hydrogen evolution reaction (HER), corrosion and passivation. To solve these problems, strategies have been proposed to modify the Zn anode interface by improving the contact between the anode and the electrolyte, thus altering the zinc anode interface. Among these, the inorganic functional protective layer can effectively enhance the uniform deposition of Zn2+, increase the reversibility of the zinc anode, and inhibit the generation of side reactions such as zinc dendrites and HER. Herein, the review starts by providing a concise summary of the challenges faced by Zn anodes and the interrelationships behind them. Subsequently, the latest advances in inorganic functional protective layers cladding zinc anodes leading to high-performance AZIBs are presented in detail, including metal compounds, inorganic non-metal materials, novel materials (MXene/MOF/COF), and other hybrid materials. The working mechanisms of the inorganic functional protective layers and modification designs for Zn anodes are described thoroughly. Finally, the challenges and future development of zinc anode interface modification as a strategy are also discussed, which provides a reference value for the practical application of AZIBs.