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

Reversable zinc-air battery (ZAB) is a promising alternative for sustainable fuel cell, but the performance is impeded by the sluggish oxygen redox kinetics owing to the suboptimal adsorption and desorption of oxygen intermediates. Here, hetero-TACs uniquely incorporate an electron regulatory role beyond the primary and secondary active sites found in dual-atom catalysts. In-situ XAFS and Raman spectroscopy elucidate Fe in FCN-TM/NC functions as the main active site, leveraging long-range electron coupling from neighbouring 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.