Fluorine‐Lodged High‐Valent High‐Entropy Layered Double Hydroxide for Efficient, Long‐Lasting Zinc‐Air Batteries
Bo Li, Jing Zhong, Hao Wang, Jialun Gu, Fucong Lyu, Shengmei Chen, Haikun Wu, Lanxi Li, Chunyi Zhi, Jian Lü, Yang Yang Li
Abstract
Abstract Efficient and stable bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts are urgently needed to unlock the full potential of zinc‐air batteries (ZABs). High‐valence oxides (HVOs) and high entropy oxides (HEOs) are suitable candidates for their optimal electronic structures and stability but suffer from demanding synthesis. Here, a low‐cost fluorine‐lodged high‐valent high‐entropy layered double hydroxide (HV‐HE‐LDH) (FeCoNi 2 F 4 (OH) 4 ) is conveniently prepared through multi‐ions co‐precipitation, where F − are firmly embedded into the individual hydroxide layers. Spectroscopic detections and theoretical simulations reveal high valent metal cations are obtained in FeCoNi 2 F 4 (OH) 4 , which enlarge the energy band overlap between metal 3d and O 2p, enhancing the electronic conductivity and charge transfer, thus affording high intrinsic OER catalytic activity. More importantly, the strengthened metal‐oxygen (M−O) bonds and stable octahedral geometry (M−O(F) 6 ) in FeCoNi 2 F 4 (OH) 4 prevent structural reorganization, rendering long‐term catalytic stability. Furthermore, an efficient three‐phase reaction interface with fast oxygen transportation was constructed, significantly improving the ORR activity. ZABs assembled with FeCoNi 2 F 4 (OH) 4 @HCC (hydrophobic carbon cloth) cathodes deliver a top performance with high round‐trip energy efficiency (61.3 % at 10 mA cm −2 ) and long‐term stability (efficiency remains at 58.8 % after 1050 charge–discharge cycles).