Strategies of Designing High-Efficiency Electrolyte Additives for Aqueous Magnesium Batteries: A Review

With the development of next-generation energy storage systems focusing on green, safe, and sustainable devices, aqueous magnesium (Mg)-air batteries have emerged as promising candidates owing to the intrinsic merits of the Mg metal anode, including low cost, large volumetric capacity, a highly negative electrode potential, and excellent safety. However, the high self-discharge rate and formed discharge products substantially impair the practical discharge performance of Mg anodes with poor anode utilization efficiency and low cell voltage. While anode alloying and electrolyte additive strategies can help mitigate this issue, designing highly efficient electrolyte additives that are compatible with the established anode remains a challenge. This review summarizes recent progress toward understanding the role of electrolyte additives for aqueous Mg batteries, provides insights into the discharge mechanism of Mg-based anode materials in different types of additive-containing electrolytes, and offers strategies for designing high-efficiency mixtures of electrolyte additives. Moreover, a highly promising direction of AI-supported and robotic workflows for the future fast design of advanced electrolyte additives for aqueous Mg batteries is discussed.