Composite Electrodeposited PbO_2/Co_3O_4 on a Ti Substrate as Positive Electrode Materials for a Hybrid Supercapacitor

PbO_2/Co_3O_4 composites were prepared on a Ti substrate by means of a composite electrodeposition method in Pb~(2+) plating solution containing dissolved nano-Co_3O_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 PbO_2/Co_3O_4 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 Co_3O_4 and β-PbO_2. In addition, the surface of the composite electrode is rough and porous. The PbO_2/Co_3O_4 composites exhibit a high specific capacitance up to 215 F/g, which is ten times higher than that of the pure-PbO_2 and two times higher than that of the pure-Co_3O_4 in 1 mol/L NaOH electrolytes.