From Surface Vermiculation to Performance Leap: A Scalable Strategy for Achieving High-Stability Aqueous Hydrogen Proton Batteries

This work introduces a novel oxygen-assisted vermiculation treatment, marking the first application of the vermiculation concept in optimizing the Cu 1 . 92 S cathode surface, significantly enhancing the performance of aqueous hydrogen proton batteries (AHPBs). Due to their nonstoichiometric structure and strong electron–ion migration capabilities, Cu 1 . 92 S cathodes were facing challenges such as tip discharge, surface dissolution and collapse, and self-discharge. To address these issues, a 30-day aging treatment in an oxygen-rich environment was employed to induce surface vermiculation. The findings reveal three major improvements postvermiculation: (1) the elimination of tip discharge effects, reducing hydrogen evolution reaction (HER); (2) the enhancement of the work function, suppressing electron escape and lowering self-discharge; (3) the strengthening of hydrogen proton adsorption, significantly boosting charge storage capacity, reaction kinetics, and cycling stability. After the vermiculation treatment, the specific capacity of Cu 1.92 S increased from 506.5 to 561.2 mAh g –1, the cycling life extended from 1600 to 2400 cycles, and charge–discharge efficiency improved. This study provides a simple and scalable post-treatment method for the surface modification of copper sulfide-based cathodes, laying the foundation for the development of high-performance and long-life aqueous energy storage systems.