P3-type layered K0.48Mn0.4Co0.6O2: a novel cathode material for potassium-ion batteries

P3-type layered K0.48Mn0.4Co0.6O2 was synthesized using a solid-state method. By stabilising into a rhombohedral structure [s.g. R3m (160)], it delivers a reversible capacity of 64 mA h g(-1) with a nominal voltage of similar to 3.0 V (vs. K/K+) and it has good cycling stability. It involves a solid-solution redox mechanism, and forms an economical and stable oxide insertion material for potassium-ion batteries.