Emerging organic potassium-ion batteries: electrodes and electrolytes

Organic potassium-ion batteries (OPIBs) can combine the merits of potassium-ion batteries (abundance, low cost and appropriate electrode potential of potassium) and the advantages of organic batteries (flexibility, ability of accommodating large ions, potentially low cost, green, recyclability and tunable molecular structure of organic electrode materials), and hence have become one of the most promising alternatives to lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Compared with other metal-ion batteries, electrodes and electrolytes are particularly important in the current studies of OPIBs. Hence, this review, for the first time, summarizes the progress and challenges of these two unique aspects in OPIBs, provides potential solutions for high-performance OPIBs, and compares them with LIBs and SIBs. We hope this review can guide the future development of OPIBs. The progress and challenges of the electrodes and electrolytes in organic potassium-ion batteries are summarized.