Exploring the Intrinsic Activity Enhancement and Charge Storage Mechanisms of O‐doped Binary Ni/Co Perovskite Fluorides in Alkaline Electrolytes for Aqueous Supercapacitors

This article explores a novel type of O anions (O^2-) doped binary Ni/Co perovskite fluorides (AB(F/O)₃, referred to as K─NC─F/O-91), and its application in aqueous supercapacitors (ASCs). Focusing on the positive impact of O doping on enhancing the electrochemical performance of perovskite fluoride materials, a series of electrochemical and physical characterization techniques can well verify that O doping can effectively improve the charge transfer ability and electrical conductivity of materials, strengthen the reactive active sites, and make them have better capacity and cycle retention rate. Furthermore, through various ex situ characterizations, the bulk phase transformation energy storage mechanism of the K─NC─F/O-91 electrode material from the typical perovskite crystal structure to the amorphous Ni─Co (hydro) oxide/hydroxyl oxide in an alkaline medium is comprehensively revealed. In conclusion, this study explored the positive impact of anionic (O^2-) doping on the ABF₃ cathode material and the structure-activity relationship, and it also delves into the energy storage mechanism of this material. It provides new ideas and methods for further in-depth research on perovskite fluoride electrode materials and offers new inspirations for the further development of high-performance aqueous supercapacitors.