Unraveling the Mechanism of Cooperative Redox Chemistry in High‐Efficient Zn<sup>2+</sup> Storage of Vanadium Oxide Cathode
Li‐Jun Zhou, Ping Li, Chenghui Zeng, Ang Yi, Jinhao Xie, Fuxin Wang, Dezhou Zheng, Qi Liu, Xihong Lu
Abstract
Abstract The inferior capacity and cyclic durability of V 2 O 5 caused by inadequate active sites and sluggish kinetics are the main problems to encumber the widespread industrial applications of vanadium‐zinc batteries (VZBs). Herein, a cooperative redox chemistry (CRC) as “electron carrier” is proposed to facilitate the electron‐transfer by capturing/providing electrons for the redox of V 2 O 5 . The increased oxygen vacancies in V 2 O 5 provoked in situ by CRC offers numerous Zn 2+ storage sites and ion‐diffusion paths and reduces the electrostatic interactions between vanadium‐based cathode and intercalated Zn 2+ , which enhance Zn 2+ storage capability and structural stability. The feasibility of this strategy is fully verified by some CRCs. Noticeably, VZB with [Fe(CN) 6 ] 3− /[Fe(CN) 6 ] 4− as CRC displays conspicuous specific capacity (433.3 mAh g −1 ), ≈100% coulombic efficiency and superb cyclability (≈3500 cycles without capacity attenuation). Also, the mechanism and selection criteria of CRC are specifically unraveled in this work, which provides insightful perspectives for the development of high‐efficiency energy‐storage devices.