Buckled-layer KMnO: a novel cathode for potassium-ion batteries.

A novel buckled-layer KMnO cathode was synthesized, featuring P2-oxygen stacking and P3-K sites. The presence of two independent manganese sites significantly influences the charge distribution and diffusion pathways of potassium ions during the charge and discharge processes, resulting in exceptional electrochemical performance. A reversible capacity of 105 mA h g at 100 mA g and remarkable rate capability of 70 mA h g at 1 A g were achieved, surpassing those of most previously reported layered transition metal oxide cathodes. The findings facilitate the development of innovative cathode materials.