Metal chalcogenides for potassium storage

Potassium-based energy storage technologies, especially potassium ion batteries (PIBs), have received great interest over the past decade. A pivotal challenge facing high-performance PIBs is to identify advanced electrode materials that can store the large-radius K+ ions, as well as to tailor the various thermodynamic parameters. Metal chalcogenides are one of the most promising anode materials, having a high theoretical specific capacity, high in-plane electrical conductivity, and relatively small volume change on charge/discharge. However, the development of metal chalcogenides for PIBs is still in its infancy because of the limited choice of high-performance electrode materials. However, numerous efforts have been made to conquer this challenge. In this article, we overview potassium storage mechanisms, the technical hurdles, and the optimization strategies for metal chalcogenides and highlight how the adjustment of the crystalline structure and choice of the electrolyte affect the electrochemical performance of metal-chalcogenide-based electrode materials. Other potential potassium-based energy storage systems to which metal chalcogenides can be applied are also discussed. Finally, future research directions focusing on metal chalcogenides for potassium storage are proposed.