Geometric Preorganization Enables Entropy-Constrained Proton Migration for Ultrafast and Stable Aqueous Proton...

The development of aqueous proton batteries (APBs) is hindered by the scarcity of electrode materials capable of regulating proton migration. Although organic electrodes are promising candidates, they often suffer from Coulombic repulsion and entropy-induced disorder, leading to performance degradation. Herein, we propose a molecular-engineering strategy based on geometric preorganization to construct low-entropy proton transport pathways by designing a C₃-symmetric triangular molecule, 1, 3, 5-tris (2, 6-dioxo-1, 2, 5, 6-tetrahydro-3, 4-dihydropyrazinyl) benzene (DBH). Its rigid trigonal scaffold preorganizes C═N and C═O redox centers, enabling symmetric charge distribution to mitigate repulsion. Moreover, geometric confinement reduces configurational disorder and restricts accessible microstates, directing proton migration along defined pathways while preserving electronic delocalization. As a result, the DBH electrode delivers high and ultrafast proton-storage capacity, reaching 277.9 mAh g^-1 at 1 A g^-1 and retaining 207.8 mAh g^-1 even at 100 A g^-1. When assembled into a full cell, the device achieves 100% capacity retention after 30 000 cycles, along with an energy density of 111.97 Wh kg^-1 and a power density of 40 441.2 W kg^-1. These results demonstrate that triangular preorganization combined with entropy regulation enables organic electrodes to exhibit high proton-storage capacity, rapid kinetics, and exceptional long-term stability.