Manganese-Based Layered Oxide Cathodes for Potassium-Ion Batteries: Progress and Outlook

Manganese-based layered oxide cathodes (MLOCs) have emerged as competitive candidates for high-performance rechargeable batteries. Building on their success in lithium-ion batteries (LIBs), MLOCs hold great promise for the rapidly developing field of potassium-ion batteries (PIBs) due to their low cost, high theoretical capacity, and environmental friendliness. However, several technical challenges, including poor structural stability, multiple phase transitions, and potassium deficiency, have hindered their progress in PIB research. This review provides a comprehensive overview of MLOCs, covering their crystal structures, reaction mechanisms, chemical compositions, and applications in PIBs. More importantly, the study critically analyzes the key challenges impeding their development and discusses potential strategies for overcoming these limitations. Recent advances in MLOC-based potassium-ion full cells are also summarized, highlighting their progress and future potential. Finally, the study offers perspectives on the future development of MLOCs in next-generation energy storage technologies. It is hoped that this review will spark strong interest from both academic and industrial communities, driving further research and accelerating the practical application of MLOCs in high-performance PIBs.