Towards High‐Performance Aqueous Zn‐Organic Batteries via Using I ⁻ ‐Based Active Electrolyte

Abstract

Abstract Organic cathodes possess inherent structural diversity and fast redox kinetics, showing great application prospects in aqueous Zn batteries. Nevertheless, most of the reported organic cathodes display low average working voltage resulting in poor energy density. Herein, diquinoxalino [2,3‐a:2′,3′‐c] phenazine (HATN)@CMK‐3 composite is utilized as cathode for aqueous zinc battery, which combines the Zn 2+ and H + co‐storage and I − /I 0 conversion by introducing I − ‐based active additive into 0.5 M Zn(OTf) 2 electrolyte. The in situ/ex situ analyses and computational studies disclose that HATN@CMK‐3 with C═N groups not only stores Zn 2+ and H + ions at low potential but also acts as a substrate to promote the conversion reaction of I − /I 0 at high potential. Accordingly, the Zn//HATN@CMK‐3 cell delivers a high average voltage of 0.75 V, prominent long‐life (10 000 cycles) and, high energy density (198 Wh kg −1 ). Remarkably, under high mass loading (10 mg cm −2 ) or low‐temperature conditions, the cell still achieves decent capacity and cycle stability.