Long-life and high-capacity aqueous proton battery based on dipyridophenazine||MnO2 electrodes

Aqueous proton batteries (APBs) have emerged as promising energy storage devices owing to the small ionic radius and low atomic mass of the proton. In this work, we develop a H + /Mn 2+ dual-cation aqueous proton battery (DC-APB) featuring an MnO 2 -based cathode and a dipyridophenazine (DPPZ)-based anode. To address the limitations of organic small-molecule electrode materials, a DPPZ/CNTs–OH composite is fabricated via a dissolution–reprecipitation method. The hydroxyl groups on CNTs–OH interact with the nitrogen sites of DPPZ through hydrogen bonding and π–π conjugation, which enhances interfacial electronic coupling and structural stability. Electrochemical evaluations reveal that the DPPZ/CNTs–OH electrode exhibits superior rate capability and cycling stability. This work presents an effective modification strategy for organic electrode materials and demonstrates that the environmentally friendly, low-cost DC-APB represents a viable alternative for sustainable green energy storage applications.