Design strategy and comprehensive performance assessment towards Zn anode for alkaline rechargeable batteries

Alkaline Zn-based primary batteries have been commercialized in the past decades. However, their success has not been extended to secondary batteries due to the poor cycle reversibility of Zn anodes. Although some research has been conducted on alkaline Zn anodes, their performance is still far from commercial requirements. A variety of degradation mechanisms, including passivation, dendrites, morphological changes, and hydrogen precipitation, are claimed responsible for the failure of alkaline Zn metal anodes. What’s worse, these constraints always interact with each other, which leads to a single strategy being unable to suppress all the issues. Therefore, a comprehensive evaluation of the positive and negative effects of various strategies on performance is important to promote the commercialization of alkaline Zn batteries. Herein, the recent progress and performance of improvement strategies for Zn anode in alkaline conditions are reviewed systematically. First, the principles and challenges of alkaline Zn anodes are briefly analyzed. Then, various design strategies for alkaline Zn anodes from the perspectives of ion and electron regulation are highlighted. Last, through a comprehensive summary of various performance parameters, the advantages and disadvantages of different strategies are compared and evaluated. On the basis of this assessment, we aim to provide more insights into the anode design of high-performance alkaline rechargeable Zn batteries.