Work

Fast and Stable NH4+/H+ Co‐Coordinated Carboxyl‐Rich N‐Heterocyclic Cathode for High‐Performance Zinc‐Organic Batteries

Year: 2024

Type: article

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 NH4+/H+ charge carriers but excludes larger and rigid Zn2+ ions, due to a lower activation energy (0.12 vs 0.29 eV). Consequently, eight‐electron NH4+/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.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202416415