Synergistic Fe−Se Atom Pairs as Bifunctional Oxygen Electrocatalysts Boost Low‐Temperature Rechargeable Zn‐Air Battery

Abstract

AbstractHerein, we successfully construct bifunctional electrocatalysts by synthesizing atomically dispersed Fe−Se atom pairs supported on N‐doped carbon (Fe−Se/NC). The obtained Fe−Se/NC shows a noteworthy bifunctional oxygen catalytic performance with a low potential difference of 0.698 V, far superior to that of reported Fe‐based single‐atom catalysts. The theoretical calculations reveal that p‐d orbital hybridization around the Fe−Se atom pairs leads to remarkably asymmetrical polarized charge distributions. Fe−Se/NC based solid‐state rechargeable Zn‐air batteries (ZABs−Fe−Se/NC) present stable charge/discharge of 200 h (1090 cycles) at 20 mA cm−2at 25 °C, which is 6.9 times of ZABs−Pt/C+Ir/C. At extremely low temperature of −40 °C, ZABs−Fe−Se/NC displays an ultra‐robust cycling performance of 741 h (4041 cycles) at 1 mA cm−2, which is about 11.7 times of ZABs−Pt/C+Ir/C. More importantly, ZABs−Fe−Se/NC could be operated for 133 h (725 cycles) even at 5 mA cm−2at −40 °C.