Influence of synthesis temperature on morphology and electrochemical performance of NiCo hydroxides for supercapacitor applications

In this work, the effects of hydrothermal growth temperature on the morphology and electrochemical characteristics of NiCo hydroxides were studied. The results of the structural and chemical analysis results support that an increase of carbonate anions originated from the hydrolysis of amines promote the morphological evolution of the NiCo hydroxides from nanosheets to nanowires as rising growth temperature. Moreover, the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) data reveal that the morphology change of NiCo hydroxides can improve the electrochemical performance. In the results, the NiCo180 sample exhibits the best electrochemical performance, with a maximum energy density of 48 Wh kg −1 at a power density of 425 W kg −1 owing to the structural advantages, which provide abundant redox active sites and efficient charge transfer.