Improvement in Both Kinetics and Areal Capacity of Organic Batteries by Intramolecular Grotthuss Proton Conduction

ABSTRACT Organic electrode materials (OEMs) offer tunable molecular structures and sustainability. To meet the requirements for applications, a high mass‐loading electrode is essential. However, as the mass loading of an electrode increases and the electrode thickens, the electrochemical kinetics significantly deteriorate. Here, we propose an intramolecular hydrogen‐bond strategy that disrupts this seesaw effect, enabling high areal capacity even at high mass‐loadings. Poly(2,3,7,8‐tetraaminophenazine‐1,4,6,9‐tetraone) (PTAPT) was synthesized as a representative material. During discharge, protons as charge carriers diffuse into the material. We use these protons to combine with active sites (C═O/C═N) of PTAPT. This interaction generates secondary intramolecular hydrogen bonds within PTAPT and concurrently forms consecutive proton transport channels. The proton diffusion energy barrier is substantially reduced, facilitating rapid proton conduction along these pathways via the Grotthuss mechanism. Consequently, a proton‐dominated charge transport mechanism occurs in PTAPT, significantly enhancing ion‐transport kinetics in thick electrodes. Furthermore, the extended proton conduction channels increase the degree of structural conjugation, endowing PTAPT with excellent electronic conductivity. A single‐layer pouch cell delivers a maximum discharge capacity of 249 mAh and a significant areal capacity of 5 mAh cm −2 . This work provides a novel strategy to improve the area capacity of OEMs, representing a key step toward their practical application.