Breaking the Stability-Activity Trade-off of Oxygen Electrocatalyst by Gallium Bilateral-Regulation for High-Performance Zinc-Air Batteries

Angew Chem Int Ed Engl. 2024 Dec 23:e202420481. doi: 10.1002/anie.202420481. Online ahead of print.

Abstract

The rational design of metal oxide catalysts with enhanced oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance is crucial for the practical application of aqueous rechargeable zinc-air batteries (a-r-ZABs). Precisely regulating the electronic environment of metal-oxygen (M-O) active species is critical yet challenging for improving their activity and stability toward OER and ORR. Herein, we propose an atomic-level bilateral regulation strategy by introducing atomically dispersed Ga for continuously tuning the electronic environment of Ru-O and Mn-O in the Ga/MnRuO2 catalyst. The Ga/MnRuO2 catalyst breaks the stability-activity restriction, showing remarkable bifunctional performance with a low potential gap (ΔE) of 0.605 V and super durability with negligible performance degradation (300,000 ORR cycles or 30,000 OER cycles). The theoretical calculations revealed that the strong coupling electron interactions between Ga and Ru-O/Mn-O tuned the valence state distribution of the metal center, effectively modulating the adsorption behavior of *O/*OH, thus optimizing the reaction pathways and reducing the reaction barriers. The a-r-ZABs based on Ga/MnRuO2 catalysts exhibited excellent performance with a wide working temperature range of -20~60 °C and a long lifetime of 2308 hours (i.e., 13,848 cycles) under a current density of 5 mA cm-2 at -20 °C.

Keywords: Gallium; Oxygen electrocatalyst; Wide-temperature; zinc-air battery.