In Situ Electrochemical Reconstruction of CoOOH@FeOOH Heterostructure for High-Power-Density Zn-Air Batteries

Efficient bifunctional electrocatalysts are crucial for the advancement of rechargeable zinc-air batteries (ZABs). In this article, we successfully synthesized a high-performance catalyst R-CoOOH@FeOOH through the oxygen evolution reaction (OER). Additionally, in situ Raman characterization results indicate that CoFe@NC-w undergo electrochemical reconstruction during the OER, leading to the formation of CoOOH and FeOOH species. This dynamic structural evolution is responsible for the enhanced OER activity of the catalyst. This transformation endowed the catalyst with exceptional OER activity. In addition, the catalyst exhibited exceptional performance in the oxygen reduction reaction, which shows a half-wave potential of 0.86 V vs. (RHE) reversible hydrogen electrode. When integrated into a ZAB, the catalyst delivers a low charging potential of 2.3 V at a high current density of 50 mA cm −2 , accompanied by an excellent long-term durability of 600 h. These findings offer viable strategies for the development of high-performance catalysts for ZAB.