Synthesis and electrochemical properties of crystalline K0.7MnO2 particles for K-ion batteries

•Using solution chemical method, the micron sized K0.7MnO2 particles were prepared for K-ion batteries.•The reversible specific capacity reaches 79 at 20 mA/g and 31 mAh/g at 400 mA/g.•A capacity retention upto 34% after 400 cycles at 100 mA/g. Large-scale energy storage and depleting lithium resources spurred interest in efficient, abundant, low-cost potassium ion battery electrode materials. In this regard, the layered K0.7MnO2 cathode was prepared by the solution chemical method. The structural and morphological analyses were performed using XRD, SEM and TEM techniques. The electrochemical properties exhibited multiple redox peaks in CV, indicating the various phase transitions during the intercalation/ de-intercalation and ordering of K-ions in the interlayer. The prepared K-ion cell delivered a reversible specific capacity of 79 and 31 mAh/g at the current densities of 20 and 400 mA/g. The structural integrity accounted for better electrochemical performance from the initial discharge capacities at high current rates.