Unlocking the potential of potassium-ion batteries: anode material mechanisms, challenges, and future directions

Potassium-ion batteries (PIBs), leveraging their abundant potassium resources, low cost, and a working principle analogous to that of lithium-ion batteries, have emerged as promising candidates for next-generation large-scale energy storage systems. Developing anode materials with high capacity and long cycle life remains a critical challenge for the practical implementation of PIBs. In recent years, extensive research efforts have been directed toward identifying novel anode materials for PIBs. This paper provides a systematic review of the research progress and technical challenges associated with PIB anode materials, focusing on four primary material systems: intercalation-type materials (e.g., graphite, amorphous carbon), conversion-type materials (e.g., metal oxides, sulfides, selenides), alloy-type materials (e.g., compounds based on P, Bi, Sb, Sn, Ge), and organic materials (e.g., conjugated polymers, carbonyl compounds). Furthermore, it highlights multi-scale optimization strategies proposed to mitigate the intrinsic limitations of each material category. This work establishes a material design framework and technical roadmap for advancing cost-effective potassium-ion battery technologies, thereby supporting sustainable development in renewable energy storage and electric transportation.