Recent advances in metal selenides as advanced anode materials for potassium-ion batteries

The rapid development of intelligent grid systems has prompted researchers to develop systems with high energy, low cost, and environmentally friendly properties in addition to lithium-ion batteries (LIBs). In this case, the potassium-ion batteries (PIBs), offering the advantages of commercial LIBs with a semi-working mechanism, are cost-effective and earth-rich. Therefore, PIBs are considered promising candidates for large-scale energy storage devices. Nowadays, the exploitation of suitable active anode materials is the focus of battery development. Metal selenides (MSes) with special structures and elevated theoretical capacities have attracted wide attention and made notable advancements. To facilitate the advancement of MSes and enhance the electrochemical performance of PIBs, understanding the inherent properties and electrochemical mechanisms of these materials is essential. In this review, various synthetic strategies and potassium storage mechanisms of MSes are introduced. Then, the applications of different kinds of MSes in PIBs are introduced in detail. Finally, the current challenges and prospective research directions are deliberated.