Abstract

Abstract The topic of sustainable and eco‐friendly energy storage technologies is an issue of global significance. To date, this heavy burden is solely addressed by lithium‐ion battery technology. However, the ongoing depletion of limited global lithium resources has restricted their future availability for Li‐ion battery technology, and hence, a significant price increase is expected. This grim situation is the driving force for the development of the “beyond Li‐ion battery” strategy involving alternatives that have several advantages over conventional Li‐ion batteries in terms of cost, durability, safety, and sustainability. Potassium, the closest neighboring alkali element after sodium, offers some unique advantages over lithium and sodium as a charge carrier in rechargeable batteries. Potassium intercalation chemistry in potassium‐ion batteries (KIBs) is successfully demonstrated to be compatible with Li‐ion batteries and sodium‐ion batteries. In addition to KIBs, potassium–sulfur and potassium–oxygen batteries have emerged as new energy‐storage systems due to their low costs and high specific energy densities. This review covers the key technological developments and scientific challenges for a broad range of rechargeable potassium batteries, while also providing valuable insight into the scientific and practical issues concerning the development of potassium‐based rechargeable batteries.