Prospects and Challenges of Practical Nonaqueous Potassium-Ion Batteries

Over the past decade, concerns over the sustainability of lithium-ion batteries (LIBs) have arisen due to the scarcity of critical elements such as lithium (Li), nickel (Ni), and cobalt (Co), prompting the exploration of alternative and complementary electrochemical energy storage technologies. Due to the more abundant resources compared to contemporary LIBs and the potentially higher specific energy than the emerging sodium-ion batteries (SIBs), potassium-ion batteries (PIBs) have attracted intensive research interest as a promising alternative to existing technologies. Nevertheless, the development of practical PIBs remains in its infancy. In this perspective, the various electrode materials and electrolytes reported for PIBs from an application point of view and identifying the most promising ones with high practical interest are first concisely discussed. Then, the pack-level specific energy, energy density, and cost analyses are presented for several PIBs chemistries, which are also compared with representative LIBs and SIBs to demonstrate the advantages of PIBs. After that, a succinct discussion is presented to evaluate the practicality of potassium metal batteries. Finally, the challenges associated with the commercialization of PIBs, providing future critical research fronts for the development of practical high-performance PIBs are outlined.