Composite Electrodeposited PbO2/Co3O4 on a Ti Substrate as Positive Electrode Materials for a Hybrid Supercapacitor

PbO2/Co3O4 composites were prepared on a Ti substrate by means of a composite electrodeposition method in Pb2+ plating solution containing dissolved nano-Co(3)O(4 )particles. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and transmission electron microscopy (TEM) were used to characterize the chemical composition and morphology of the PbO2/Co3O4 composites. The electrochemical and capacitance performance of the composites were investigated by cyclic voltammetry (CV), charge-discharge tests and electrochemical impedance (EIS). The results indicate that the composites comprise rutile phase Co3O4 and beta-PbO2. In addition, the surface of the composite electrode is rough and porous. The PbO2/Co3O4 composites exhibit a high specific capacitance up to 215 F/g, which is ten times higher than that of the pure-PbO2 and two times higher than that of the pure-Co3O4 in 1 mol/L NaOH electrolytes.