Recent advances and future perspectives in engineering of bifunctional electrocatalysts for rechargeable zinc–air batteries

Highlights

• Battery configuration and oxygen electrochemical reactions of zinc–air battery (ZAB) systems have been discussed.

• Engineering of the air electrode and its impact at the overall performance of ZABs has been highlighted.

• Recent advances and engineering principles of air electrocatalysts for rechargeable ZABs have been analyzed.

• Analysis and comparison of the performance of different oxygen electrocatalysts for rechargeable ZABs have been summarized.

• Challenges and future perspectives of oxygen electrocatalysts for rechargeable ZABs have been outlined.

Abstract

The engineering of efficient oxygen electrocatalysts are crucially desired for electrically rechargeable zinc–air batteries (ZABs) to drive oxygen electrochemical reactions. ZABs have attracted great studies attentions because of their excessive energy density, high abundance of zinc, value-effectiveness, and high safety, in addition to low-level of pollutants. However, technical challenges associated with sluggish rates of oxygen reactions have not begun to be resolved. In this review, ZAB configuration and basic aspects of oxygen electrochemistry of the air electrode are in short delivered first. Then, the latest improvement in engineering of oxygen electrocatalysts for ZABs is specific mentioned following four aspects: precious metals/alloys, transition metal, transition-metal oxides (perovskites, single/mixed-metal oxides, and spinels), and carbon-based materials. Finally, challenges and future perspectives of engineering of bifunctional catalysts for ZABs with high catalytic activity and durability are recommended.