Recent progress of transition metal-based bifunctional electrocatalysts for rechargeable zinc–air battery application

Rechargeable zinc–air battery (RZAB) is one of the most promising energy-storage devices for our renewable energy economy. However, many hurdles limit its practical application. Main challenge is the sluggish reaction kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in discharging and charging processes, respectively. Non-precious metal catalysts have been found to provide a great potential for electrocatalysis of oxygen-involved reactions as compared to noble metal-based catalyst materials. In this article, last three years advancement of transition metal-based bifunctional electrocatalyst is reviewed. Finally, the conclusion and future perspectives of transition metal-based bifunctional oxygen electrocatalysts for RZAB application are outlined.