Vanadium-based cathode materials for rechargeable magnesium batteries

Rechargeable magnesium batteries (RMBs) are promising candidates for large-scale energy storage due to the low cost, abundant reserve, high volumetric capacity, and low redox potential of Mg anodes. Since the high theoretical capacity and energy density originate from the rich valence states of vanadium (from +2 to +5) and distortion of V–O polyhedrons, vanadium-based cathode materials are very attractive for RMBs. This paper provides a comprehensive overview of vanadium-based cathode materials for RMBs including vanadium oxides, vanadates, vanadium chalcogenides, and vanadium-based phosphates. The structure, electrochemical properties, optimization strategies, structure–performance relationship, and reaction mechanisms of various vanadium-based cathode materials are described. The challenges, prospective, and future research directions of vanadium-based electrode materials are discussed.