Hierarchical mesoporous octahedral K2Mn1-xCoxFe(CN)6 as a superior cathode material for sodium- ion batteries

A new Prussian blue analogue, hierarchical mesoporous octahedral K2Mn1-xCoxFe(CN)(6) (x = 0, 0.05, 0.1 and 0.2), has been successfully synthesized for the first time via a simple magnetically stirred process. K2Mn1-xCoxFe(CN)(6) (x-0, 0.05, 0.1 and 0.2) was selected as a cathode material for sodium ion batteries to increase their lattice parameters, along with the large available tunnels for Na+ diffusion. We also introduce cobalt into the framework to stabilize the crystal structure and improve the electronic conductivity of the KMHFC particles. These composites are characterized via powder X-ray diffractometry, and scanning and transmission electron microscopy. Among the samples, K2Mn0.9Co0.1Fe(CN)(6) exhibits the best electrochemical performance as a cathode material for sodium ion batteries, with a discharge capacity of 116 mA h g(-1) after 150 cycles at 10 mA g(-1). This superior electrochemical property could be ascribed to its unique hierarchical architecture, improved electronic conductivity, and robust structure.