Abstract

Nowadays, the energy crisis and environmental pollution have become a severe social issue preventing sustainable developments. Seeking inexpensive and green energy devices that can be utilized and integrated is an important solution for the above-mentioned obstacles. Rechargeable batteries are deemed as important and promising carriers to convert energies because of their portability and high efficiency. For decades, considerable efforts have been devoted to lithium-ion batteries (LIBs) among all secondary batteries, which have achieved tremendous successes in portable electronics because of their high energy density and good rechargeable ability. However, the small amount of lithium in nature restrains the LIBs in practical applications. Consequently, to satisfy emergent demands for energy devices, potassium-ion batteries (PIBs), which are considered promising supplements for lithium-ion batteries in the future, have garnered significant attention owing to the abundant reserves, the large-scale energy storage, the lower cost, and the relatively low reduction potential. In this chapter, we discuss the current development of PIBs, including working principles, solid electrolyte interphase (SEI), electrode materials, fabrication methods, electrochemical performance, and applications. At the same time, the prospects and challenges in the practical application of PIBs are also discussed. We anticipate that this chapter would provide a direction for developing the PIBs with high electrochemical performance.