Redistribution and activation of inert N-configuration in metallic electron donor towards boosted oxygen reaction kinetics for zinc-air batteries

The utilization of metallic nitrides as air–cathode electrocatalysts is promising for sparking fresh vitality to rechargeable zinc-air batteries, but successful case is rare due to their limitation to catalyze one specific reaction. Here, mild topochemical evolution coupled with assembly self-templating is presented to achieve electrocatalytic furnishing on the 2D metallic VN nanosheet. Density functional theory (DFT) calculations predict that lowered energy barriers for potential limiting steps can be achieved by hybridization VN with cost-effective active species. Metallic VN hybrid architecture buffered with flocculent carbon matrix is constructed, featuring decoration of active FeNi alloy nanoparticles (VN-FeNiA@FC). Particularly, prominent interfacial electron delocalization owing to the electron donating from VN boosts the oxygen reaction kinetics. As a stride forward, the redistribution and activation of inert N-configuration from host VN to the formation of Fe/Ni–N_x are revealed, contributing to promoted exposure of active sites. As a proof of concept, a rechargeable zinc-air battery based on bifunctional VN-FeNiA@FC catalyst exhibits desired galvanostatic charge/discharge stability for over 200 h, surpassing the noble metal-based benchmarks (Pt/C + Ir/C). This study is expected to open new avenues for designing hybrid materials with modulated electronic environment and interface chemistry for electrocatalytic applications and beyond.