Post-lithium ion battery era: Recent advances in rechargeable potassium-ion batteries

Abstract

Lithium shortage and growing demand for electricity storage encourage researchers to look for new alternative energy storage materials. Due to the abundant potassium resources, similar redox potential to lithium metal and low cost, potassium ion batteries (PIBs), as one of the promising alternatives, are applied in energy storage research recently. However, PIBs do not have adequate competition in their electrochemical efficiency because the molar volume of potassium ions is higher than those in lithium and sodium ions. Therefore, for the better application and development of PIBs, finding suitable anode and cathode materials becomes the most important task currently. The latest developments in electrode materials for PIBs have been outlined in depth in this review. It focuses on novel electrode material structure design and synthesis methods, ingenious optimization and tuning strategies, and the explanation of intrinsic reaction mechanism. The effects of organic electrolytes and aqueous electrolytes on battery systems are compared and clarified. Finally, theoretical and viable insight is given to the challenges posed by the creation and practical application of PIBs in future.