Buckled-layer K_1.39Mn₃O₆: a novel cathode for potassium-ion batteries

A novel buckled-layer K_1.39Mn₃O₆ 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^-1 at 100 mA g^-1 and remarkable rate capability of 70 mA h g^-1 at 1 A g^-1 were achieved, surpassing those of most previously reported layered transition metal oxide cathodes. The findings facilitate the development of innovative cathode materials.