Trifunctional electrocatalyst with accurate surface reconstruction for zinc-air batteries and water electrolyzers

Exploiting cost-effective trifunctional electrocatalysts toward oxygen evolution reaction, hydrogen evolution reaction and oxygen reduction reaction is important for sustainable energy conversion and storage devices yet challenging. Here, we report a single-phase trifunctional electrocatalyst Sr₂CoRuO_6-δ with well-defined super-exchange double perovskite structure, which can efficiently catalyze oxygen evolution, hydrogen evolution and oxygen reduction under alkaline conditions. As an air electrode, Sr₂CoRuO_6-δ delivers high peak power density of 216 mW cm^-2, high specific capacity of 748 mAh g^-1 and long lifespan up to 1000 h for liquid rechargeable zinc-air batteries, as well as broad temperature and deformation adaptability for solid-state flexible zinc-air batteries. Furthermore, an anion exchange membrane water electrolyzer employing Sr₂CoRuO_6-δ as both cathode and anode requires a cell voltage of 1.90 V at the current density of 1 A cm^-2 and shows a stable and rapid response when coupled with fluctuating solar electricity. Combining complementary in-situ and microscopic techniques, spatiotemporal surface reconstruction behavior of Sr₂CoRuO_6-δ under varied reactions is comprehensively investigated and true active components are identified.