Constructing Bipolar Dual‐Active Sites through High‐Entropy‐Induced Electric Dipole Transition for Decoupling Oxygen Redox
Q. Zhang, Zhiyang Zheng, Runhua Gao, Xiao Xiao, Miaolun Jiao, Boran Wang, Guangmin Zhou, Hui–Ming Cheng
Abstract
Abstract It remains a significant challenge to construct active sites to break the trade‐off between oxidation and reduction processes occurring in battery cathodes with conversion mechanism, especially for the oxygen reduction and evolution reactions (ORR/OER) involved in the zinc‐air batteries (ZABs). Here, using a high‐entropy‐driven electric dipole transition strategy to activate and stabilize the tetrahedral sites is proposed, while enhancing the activity of octahedral sites through orbital hybridization in a FeCoNiMnCrO spinel oxide, thus constructing bipolar dual‐active sites with high‐low valence states, which can effectively decouple ORR/OER. The FeCoNiMnCrO high‐entropy spinel oxide with severe lattice distortion, exhibits a strong 1s→4s electric dipole transition and intense t 2g (Co)/e g (Ni)‐2p(O L ) orbital hybridization that regulates the electronic descriptors, e g and t 2g , which leads to the formation of low‐valence Co tetrahedral sites (Co th ) and high‐valence Ni octahedral sites (Ni oh ), resulting in a higher half‐wave potential of 0.87 V on Co th sites and a lower overpotential of 0.26 V at 10 mA cm −2 on Ni oh sites as well as a superior performance of ZABs compared to low/mild entropy spinel oxides. Therefore, entropy engineering presents a distinctive approach for designing catalytic sites by inducing novel electromagnetic properties in materials across various electrocatalytic reactions, particularly for decoupling systems.