Asymmetrical Triatomic Sites with Long-Range Electron Coupling for Ultra-Durable and Extreme-Low-Temperature Zinc-Air...

Reversible zinc-air battery (ZAB) is a promising alternative for sustainable fuel cells, but the performance is impeded by the sluggish oxygen redox kinetics owing to the suboptimal adsorption and desorption of oxygen intermediates. Here, hetero-trimetallic atom catalysts (TACs) uniquely incorporate an electron regulatory role beyond primary and secondary active sites found in dual-atom catalysts. In situ X-ray absorption fine structure (XAFS) and Raman spectroscopy elucidate Fe in FeCoNi SA catalyst (FCN-TM/NC) functions as the main active site, leveraging long-range electron coupling from neighboring Co and Ni to boost catalytic efficiency. The ZAB equipped with FCN-TM/NC exhibits ultra-stable rechargeability (over 5500 h at 1  mA cm^-2 under -60 °C). The in-depth theoretical and experimental investigations attribute such superior catalytic activity to the asymmetric FeN₄ configuration, long-distance electron coupling, modulated local microenvironment, optimized d orbital energy levels, and lower energy barrier for bifunctional oxygen electrocatalysis. This work provides a comprehensive mechanistic understanding of the structure-reactivity relationship in TACs for energy conversion.