Fe4[Fe(CN)6]3: a cathode material for sodium- ion batteries

Insoluble Prussian blue (IPB), Fe-4[Fe(CN)(6)](3), is synthesized at room temperature and found to achieve a relatively high storage capacity of 146 mA h g(-1) (at a 20 mA g(-1) rate) as the cathode material for Na-ion batteries with high potential plateaus. XRD, SEM and TEM are employed to characterize the morphology and microstructure of the as-synthesized IPB. First-principles calculation is introduced to study the electrochemical mechanism. Generally, the environmental friendliness and low cost of the material make it possible to be used for large-scale electric storage applications.