Enhanced electrochemical performance of nano-MnO2 modified by Ni(OH)2 as electrode material for supercapacitor

Ni(OH)2 was compounded to MnO2 in an easy liquid phase process to improve the diffusion process of the electrode. The as-prepared materials were a mixture of amorphous and nanocrystalline with aggregated nanoparticles forming slit-shaped pore structures. The composite has higher specific surface area and smaller pore volume compared with pristine MnO2. Electrochemical properties of the electrodes were carried out with cyclic voltammetry (CV), galvanostatic charge–discharge tests, and electrochemical impedance spectroscopy (EIS). The MnO2/Ni(OH)2 composites exhibited enhanced electrochemical properties than that of pristine MnO2. Remarkably, the composite which contains 3 % Ni(OH)2 exerted the best discharged specific of 408 F g−1 under 0.2 A g−1, much higher than 247 F g−1 of pristine MnO2 at the same current density. Better rate capability and cycling stability were also realized by the same composite in comparison.