Recent Progress and Prospects on Dendrite-free Engineerings for Aqueous Zinc Metal Anodes

Rechargeable zinc-ion batteries with mild aqueous electrolytes are one of the most promising systems for large-scale energy storage as a result of their inherent safety, low cost, environmental-friendliness, and acceptable energy density. However, zinc metal anodes always suffer from unwanted dendrite growth, leading to low Coulombic efficiency and poor cycle stability and during the repeated plating/stripping processes, which substantially restrict their further development and application. To solve these critical issues, a lot of research works have been dedicated to overcoming the drawbacks associated with zinc metal anodes. In this overview, the working mechanisms and existing issues of the zinc metal anodes are first briefly outlined. Moreover, we look into the ongoing processes of the different strategies for achieving highly stable and dendrite-free zinc metal anodes, including crystal engineering, structural engineering, coating engineering, electrolyte engineering, and separator engineering. Finally, some challenges being faced and prospects in this field are provided, together with guiding significant research directions in the future.