Recent Progress on Sb- and Bi-based Chalcogenide Anodes for Potassium-Ion Batteries.

Potassium ion batteries (PIBs) are potential alternative energy storage systems to lithium ion batteries (LIBs), due to elemental abundance of potassium, low cost and similar working principle to LIBs. Recently, metal chalcogenides (MCs) have gained enormous interests, especially antimony (Sb)-, bismuth (Bi)-based chalcogenides because they were able to undergo alloying/conversion dual mechanism, which can provide higher specific capacity and energy density (K3 Sb∼660 mA h g-1 , K3 Bi∼385 mA h g-1 ). However, several challenges hinder the development of Sb-, Bi-based chalcogenide anode materials for PIBs, such as huge volume expansion during potassiation, unstable solid-electrolyte interface (SEI), slow reaction kinetics, and polychalcogenide-induced shuttle effect. In this review, the current state-of-the-art Sb-, Bi-based chalcogenides are comprehensively summarized, including the reaction mechanism, electrochemical performance, ingenious nanostructures, electrolyte systems, and prospects for future development. This review contributes to understanding the K+ storage mechanism and the interaction between active materials and electrolytes, providing guidance and foundation for the design of next-generation high-performance PIBs.