New NiMoO4/CoMoO4 composite electrodes for enhanced performance supercapacitors

Abstract

New NiMoO4/CoMoO4 composite materials on Ni foam were successfully synthesized by a facile hydrothermal method using the mixture powers of Ni(NO3)2·6H2O and Co(NO3)2·6H2O as raw materials. The phase composition, microstructure, and morphology of the as-prepared composites were investigated by XRD, FTIR, SEM, EDS, and XPS. The electrochemical behaviors of the composites were tested by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The results indicated that the as-prepared composites are uniformly distributed on the surface of Ni foam with diameters between 2 and 3 μm, and the NiMoO4/CoMoO4 composite displays the best electrochemical properties when the molar ratio of Ni/Co is 1:1. In 3 mol L−1 KOH electrolytes with current densities of 1, 4, 7, and 10 A g−1, the discharge specific capacitance of NiMoO4/CoMoO4 composite is 2221, 1868, 1678, and 1568 F g−1, respectively, indicating its promising applications for high electrochemical performance energy storage device.