Advances in Alloy‑Based Anode Materials for Magnesium Rechargeable Batteries

Magnesium rechargeable batteries (MRBs) have attracted significant attention due to their inherent safety and cost advantages in recent years. The utilization of commercially pure magnesium metal as an anode material is predominant in MRBs, attributed to its cost‐effectiveness and substantial theoretical capacity. However, the further development of MRBs is impeded by the poor reversibility of Mg plating/stripping and Mg‐storage reactions. The formation of a passivation film on the surface of a magnesium metal anode blocks Mg ion diffusion when interfaced with conventional electrolytes. To address this challenge, inspired by breakthroughs in graphite‐based anode materials for lithium‐ion batteries, replacing Mg metal anodes with alloy‐based anode materials has been proposed. This approach can improve reversibility and electrolyte compatibility, although the higher operating potential of many alloy anodes relative to Mg/Mg 2+ may reduce the voltage of practical full cells. This paper provides a comprehensive review of recent advancements in alloy anodes based on the type of elements and discusses their theoretical assessments, achievable capacities, synthesis methodologies, battery performance, electrochemical behaviors, and intrinsic reaction mechanisms.