Hydrogen‐Bonded Supramolecular Networks of Carboxyl‐Functionalized Hexaazatriphenylene for Ultradurable Aqueous Proton Batteries

ABSTRACT Aqueous proton batteries offer rapid proton transport kinetics and cost‐effectiveness, yet imine‐based electrode materials suffer from low active‐site utilization, sluggish kinetics, and electrolyte dissolution. Herein, we design and synthesize hexaazatriphenylene‐hexacarboxylic acid (HATN‐6COOH), whose abundant carboxyl groups construct a hydrogen‐bonded supramolecular architecture that simultaneously addresses these limitations through three synergistic mechanisms: (i) electron‐withdrawing modulation of the electronic structure, (ii) construction of efficient proton transport pathways via the Grotthuss mechanism, and (iii) suppression of active‐material dissolution through supramolecular stabilization. Consequently, HATN‐6COOH delivers a high specific capacity of 201 mAh g − 1 at 0.5 A g − 1 , outstanding rate capability (89.1% retention at 10 A g − 1 ), and exceptional cycling stability (90.4% retention after 30 000 cycles at 5 A g − 1 ). Operando Raman, ex situ XPS, and FTIR analyses confirm reversible H + storage at C═N sites, with the carboxyl C═O groups remaining inactive under the operating potential window, while dissolution tests verify that the hydrogen‐bonded network effectively prevents active‐material leaching in strong acidic electrolytes. A HATN‐6COOH//MnO 2 full cell retains 82.6% capacity after 30 000 cycles, validating practical applicability. This work proposes a promising molecular design strategy for high‐performance organic batteries via rational supramolecular engineering.