Stabilizing RuO2 via Gd2O3-mediated dual interfaces for long-cycling Zn-air batteries

The development of oxygen reduction and evolution reaction (ORR/OER) electrocatalysts for zinc-air batteries (ZABs) is impeded by insufficient stability. This study demonstrates progress in stabilizing the commercial OER electrocatalyst (RuO 2 ) by easily integrating a composite ORR electrocatalyst containing cobalt and Gd 2 O 3 nanodots, resulting in an advanced ZAB cathode. An in-situ formed Co-Gd 2 O 3 interface enhances the electronic environment of cobalt through strong metal-support interaction, thereby boosting intrinsic ORR activity and stability. Crucially, during battery cycling, Gd 2 O 3 and RuO 2 dynamically reconstruct to form a stable Gd 2 O 3 -RuO 2 interface. This facilitates directional electron transfer from Gd to Ru, effectively preventing excessive oxidation, dissolution, and structural collapse of RuO 2 under high-potential conditions, thus stabilizing the OER process. This synergistic “dual interface” strategy combines the in-situ constructed Co-Gd 2 O 3 interface with the dynamically reconstructed Gd 2 O 3 -RuO 2 interface, collectively enhancing the durability of ZAB cathode catalysis. Consequently, the assembled ZAB maintains stable cycling for 3485 cycles at 10 mA·cm −2 , demonstrating much longer stability than that of the commercial PtC/RuO 2 electrocatalyst.