Superdurable Bifunctional Oxygen Electrocatalyst for High-Performance Zinc–Air Batteries

The development of high-efficiency and durable bifunctional electrocatalysts for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical for the widespread application of rechargeable zinc–air (Zn–air) batteries. This calls for rational screening of targeted ORR/OER components and precise control of their atomic and electronic structures to produce synergistic effects. Here, we report a Mn-doped RuO 2 (Mn-RuO 2 ) bimetallic oxide with atomic-scale dispersion of Mn atoms into the RuO 2 lattice, which exhibits remarkable activity and super durability for both the ORR and OER, with a very low potential difference (Δ E ) of 0.64 V between the half-wave potential of ORR ( E 1/2 ) and the OER potential at 10 mA cm –2 ( E j 10 ) and a negligible decay of E 1/2 and E j 10 after 250 000 and 30 000 CV cycles for ORR and OER, respectively. Moreover, Zn–air batteries using the Mn-RuO 2 catalysts exhibit a high power density of 181 mW cm –2, low charge/discharge voltage gaps of 0.69/0.96/1.38 V, and ultralong lifespans of 15 000/2800/1800 cycles (corresponding to 2500/467/300 h operation time) at a current density of 10/50/100 mA cm –2, respectively. Theoretical calculations reveal that the excellent performances of Mn-RuO 2 is mainly due to the precise optimization of valence state and d -band center for appropriate adsorption energy of the oxygenated intermediates.