The Electrochemical Capacitive Behaviors of NiO Nanoparticles

The NiO nanoparticles were synthesized at different temperatures using a simple hydrothermal precipitation method and then calcined at 400 °C for 2 h. The morphology, crystalline structures and functional groups of nano NiO materials were investigated by SEM, XRD and FT-IR, respectively. Electrochemical properties were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and cyclic charge-discharge tests. The results showed that the particle size of nano NiO was around 10 nm and dependent of temperature in the range of 120-180 °C. Their specific capacitance achieved to 630 F/g at the scan rate of 5 mV/s (vs. Hg/HgO). The cycling test results showed that nano NiO exhibited good cycling performance after 500 cycles.