Additives for Aluminum-Air Batteries: A Review

The growing demand for efficient energy storage systems directs substantial research attention toward aluminum-air batteries, primarily due to their low cost and the abundant availability of aluminum. Among the various strategies aimed at enhancing their performance, the incorporation of electrolyte additives emerges as one of the most cost-effective and efficient approaches. Electrolyte additives, usually constituting approximately 1% of the total electrolyte composition, actively influence the physicochemical characteristics of both the electrolyte and the electrode-electrolyte interface, thereby contributing to marked enhancements in the overall performance of aluminum-air batteries. Despite their low concentrations, additives play a fundamental role in enhancing the efficiency and extending the service life of aluminum-air batteries by stabilizing the electrode-electrolyte interface and promoting favorable electrochemical performance. This review investigates the primary factors propelling the advancement of aluminum-air batteries by considering the diverse functions of electrolyte additives. The additives are classified into three categories: organic, inorganic, and hybrid. This comprehensive analysis aims to serve as a key resource for the informed selection and development of electrolyte additives, thereby fostering continued innovation in aluminum-air battery technologies.