Fast and Stable NH<sub>4</sub><sup>+</sup>/H<sup>+</sup> Co‐Coordinated Carboxyl‐Rich <i>N</i>‐Heterocyclic Cathode for High‐Performance Zinc‐Organic Batteries
Yehui Zhang, Qi Huang, Ziyang Song, Ling Miao, Yaokang Lv, Lihua Gan, Mingxian Liu
Abstract
Abstract Designing multi‐active‐site organic cathodes with new redox‐motif chemistry is critical but still challenging for propelling better Zn‐organic batteries (ZOBs). Here an 8 fold‐active‐site N ‐heterocyclic organic molecule cathode is reported, 4,4′,4″,4‴‐(pyrazino[2,3‐g]quinoxaline‐2,3,7,8‐tetrayl)tetrabenzoic acid (TBA) with dual carboxyl/imine moieties toward superior ZOBs. Compared with N ‐heterocyclic phenazine, rich carboxyl motifs in TBA serve as both redox sites and electron structure regulators, affording enhanced electron delocalization activity (−4.54 vs −1.078 a.u.) and low‐energy‐barrier redox kinetics (2.14 vs 2.45 eV). TBA redox‐exclusively couples with small‐hydration‐size and high‐kinetics NH 4 + /H + charge carriers but excludes larger and rigid Zn 2+ ions, due to a lower activation energy (0.12 vs 0.29 eV). Consequently, eight‐electron NH 4 + /H + co‐storage endows fast and stable Zn||TBA battery with high capacities (302 mAh g −1 at 0.5 A g −1 ; 151 mAh g −1 at 20 A g −1 ) and ultralong life (20000 cycles). This work opens new horizons to build new‐type multielectron redox motifs for advanced zinc‐organic batteries.