Chloride-Based Electrolytes for Long-Lifespan Tin Metal Batteries

Aqueous tin metal batteries are gaining traction for their safety, cost-effectiveness, and high capacity. However, the use of strong acids, such as sulfuric acid, has resulted in significant electrode corrosion and unwanted hydrogen evolution. To address these challenges, we propose a low-acidity chloride-based electrolyte (pH=1.09) that eliminates the need for strong acids while achieving high reversibility and dendrite-free tin plating. The system demonstrates remarkable plating efficiencies of up to 99.97% and remains stable under various conditions, including low currents and extended rest periods. With a prolonged battery life exceeding 3,000 hours, this work offers crucial insights into optimizing aqueous tin metal battery systems and mitigating issues related to Sn²⁺ oxidation on the cathode. The findings pave the way for the development of robust and scalable tin metal batteries.