Electrochemical corrosion behavior of magnesium anodes

Magnesium (Mg) metal is an attractive anode candidate for next-generation energy storage owing to its high volumetric capacity, natural abundance, low cost, and favorable safety characteristics. Yet, in liquid electrolytes, its high interfacial reactivity and sluggish Mg 2+ transport drive persistent competition among corrosion, passivation, and reversible electrochemistry, limiting anodic utilization in primary systems and cycling reversibility in rechargeable batteries. Here, we present a comprehensive review of the electrochemical corrosion behavior of Mg anodes across aqueous and non-aqueous liquid electrolytes, treating corrosion as a central organizing principle while distinguishing it from chemical passivation and broader electrochemical irreversibility. In aqueous systems, Mg corrosion is governed by the dynamic coupling of anodic dissolution, hydrogen evolution, passive-film breakdown, localized attack, and corrosion-product reconstruction, with electrolyte chemistry controlling the balance between useful Mg utilization and parasitic consumption. In non-aqueous systems, the problem shifts toward the interplay among solvation, desolvation, electrolyte decomposition, interphase chemistry, and Mg 2+ transport, where a chemically stable interface is not necessarily electrochemically functional. We further examine how electrolyte and additive engineering, artificial interphases, alloying, microstructure regulation, and impurity control can redirect these interfacial processes toward more stable operation. Finally, emerging theory- and data-driven approaches, including density functional theory (DFT), ab initio molecular dynamics (AIMD), high-throughput screening, and machine learning (ML), are discussed as tools for uncovering corrosion mechanisms and accelerating materials discovery. By connecting interphase chemistry, corrosion kinetics, Mg 2+ transport, and system-specific performance, this Review provides a mechanistic framework for the rational design of durable Mg-based electrochemical systems.