Potassium-based electrochemical energy storage devices: Development status and future prospect

Abstract

The demand for large energy storage systems is consecutively increasing, which requires low-cost and renewable batteries technologies with sustainable performance. Potassium, as the nearest element to sodium and lithium in the IA group of the periodic table, possesses excellent superiorities in electrochemical energy storage devices. Correspondingly, numerous electrode materials with excellent stability and capability have been developed for rechargeable potassium-ion batteries (KIBs). In this review, recent results of electrode materials concerning different types of electrolytes (organic electrolyte, aqueous electrolyte, and all-solid-state electrolyte) for rechargeable KIBs are summarized. An overall content of ongoing cathode/anode electrode materials utilized in rechargeable KIBs with organic electrolyte is reviewed. The topic focuses on employing organic compounds, Prussian blue analogues, layered oxides, and polyanionic compounds as cathode. In addition, different anode materials such as intercalation compounds, alloy compounds, conversion compounds, and organic compounds were discussed. Furthermore, the current research progress of other potassium-based electrochemical energy storage devices (KEES) with low costs and high specific energy densities, such as potassium-ion hybrid capacitors (KIHCs) and potassium dual-ion batteries (KDIBs), are also summarized. Finally, we pointed out the current challenges and future directions of KEES.