The binder-free supercapacitor electrode of nano-sized cube-shaped manganese hexacyanoferrate (Mn-HCF) with Prussian blue structure was prepared on graphite sheet by pulse galvanostatic electrodeposition method at a current density of 100 μA/cm2. The structure and morphology of the electrodes were characterized by X-ray diffraction and field emission scanning electron microscopy. The XRD pattern confirmed that the Mn-HCF could be successfully deposited via this process. From SEM images, a clear nano-sized cube-shaped microstructure is observed for Mn-HCF film. Also, the pseudocapacitive performances of the prepared Mn-HCF electrode were investigated in a three electrode cell containing 0.5 M Na2SO4 aqueous solution as the electrolyte with adequate electrochemical experiments such as cyclic voltammetry (CV) and galvanostatic charge-discharge measurements. The prepared Mn-HCF electrode exhibits excellent pseudocapacitive behavior with a higher specific capacitance of 275 F g-1 at 1.0 A g-1, better rate capability with a capacity of 226 F g-1 even at a high current density of 5.0 A g-1. These can be attributed to the uniform deposition of Mn-HCF onto the porous graphite substrate, binder-free nature of the as-prepared electrode and uniform and nano-sized crystals of active material fabricated by electrodeposition method, facilitating electrolyte ion diffusion and electron transfer to the Mn-HCF active material. Overall, it is found that the as-prepared binder-free Mn-HCF electrode can be a promising pseudocapacitance electrode for high-performance energy storage applications.
