Recent Progress in Rechargeable Potassium Batteries

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.