Advanced V-based materials for multivalent-ion storage applications

Multivalent-ion batteries, as promising alternative or supplementary technologies to lithium-ion batteries, have increasingly attracted attention recently. Various advanced materials have been presented to pursue potential breakthroughs in energy and power. Among them, vanadium (V)-based materials benefiting from abundant resources, various polymorphs and valences, especially most with large interlayer spacings, are good candidates for multivalent-ion storage. However, limited by multiple inherent issues, e.g., strong electrostatic interactions, poor electronic conductivity, structure collapse or materials dissolution under battery operation, etc. , various strategies have sprung many advanced materials and applications and also brought about new challenges that are in urgent need to clarify and summarize. Hence, advanced V-based compounds developed for multivalent-ion storage in the past few years are selectively summarized and systematically analyzed, including vanadium oxides and sulfides, vanadates, and V-based MXenes and phosphates. Not only crystal structures and electrochemical properties but also mainstream ion storage mechanisms are critically reviewed. Through analyzing the challenges accompanying multivalent-ion storage, potential opportunities are anticipated.