Anode optimization strategies for zinc–air batteries

With issues of energy security and environmental crisis intensifying, we urgently need to develop energy storage systems with high energy density and high safety. Zinc–air batteries have attracted extensive attention for their energy density, safety, and low cost, but problems with the zinc anode—such as hydrogen evolution, corrosion, passivation, dendrite proliferation, and deformation—have led to zinc–air batteries with low Coulombic efficiency and short cycle life; these remain the key obstacles hindering the batteries’ further development. In this review paper, we briefly describe the reaction mechanism of zinc–air batteries, then summarize the strategies for solving the key issues in zinc anodes. These approaches are divided into three aspects: structural designs for the zinc anode; interface engineering; and electrolyte selection and optimization. We finish by offering some suggestions for future research directions to improve the zinc anode in zinc–air batteries.