Cathodic electrodeposition and electrochemical response of manganese oxide pseudocapacitor electrodes

In this work, we reported the cathodic electrodeposition of manganese oxide films, from nitrate based electrolytes, for pseudocapacitors working in alkaline media. The correlation of the post–thermal treatment, the deposition potential, the electrolyte concentration and the applied charge on surface morphology and electrochemical response of the electrodeposited films were studied. Morphological characteristics and electrochemical response varied depending on the deposition parameter. Via the optimized deposition process, hierarchical nanoparticles/nanoflakes Mn 3 O 4 films were obtained, exhibiting a high specific capacitance value of 416 F g −1 at an applied current density of 1 A g −1 in 1 M NaOH electrolyte. The films exhibited specific capacitance retention of 64% when increasing the current density from 1 A g −1 to 10 A g −1 . The films showed the specific capacitance value 196 F g −1 after continuous charge–discharge at 1 A g −1 for 1000 cycles, thus pointing out the possibility of using cathodically deposited manganese oxide films as electrodes for pseudocapacitors.