The Trade-Offs in the Design of Reversible Zinc Anodes for Secondary Alkaline Batteries

Zinc-based batteries have long occupied the largest share of the primary battery market, but this advantage has not continued in the secondary battery market. This is mainly because the cycling performance of secondary zinc-based batteries is significantly limited by the poor reversibility of zinc electrodes, including the formation of zinc dendrites, electrode deformation, corrosion, and hydrogen evolution. To solve the above problems, researchers have developed many novel strategies, such as surface coating, use of electrode additives, use of electrolyte additives, and electrode structure design. However, the implementation of these strategies inevitably requires consideration of trade-offs because the core factors that limit the reversibility of zinc electrodes are not isolated but intertwined. Therefore, fully understanding the trade-offs in the zinc electrode design process is necessary to fundamentally improve the cycling performance of the zinc electrode and construct a practical secondary zinc-based battery. This perspective gives an introduction to various problems that limit the cycling of zinc electrodes and discusses the theoretical causes of these problems. The trade-offs in various typical strategies are systematically analyzed, and their positive and negative effects on performance are discussed. This work aims to provide insights for the development of highly reversible zinc anodes for practical secondary zinc-based batteries.