Preparation and Supercapacitive Performance of Lead Dioxide Electrodes with Three-Dimensional Porous Structure

Resumo

The three-dimensional porous structure PbO₂ electrodes (3D-PbO₂ electrodes) were prepared in the lead nitrate solution by potentiostatically electrodeposition method using oxygen bubble as dynamic template, which can be used as the positive materials of the supercapacitors. The morphology and structure of 3D-PbO₂ electrodes were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The supercapacitive performance of 3D-PbO₂ electrodes were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge tests (GCD) and electrochemical impedance spectroscopy (EIS). The specific capacitance of 3D-PbO₂ electrodes can reach 195.6 F g^–1 at 0.2 A g^–1, which is 2.8 times higher than that of Flat-PbO₂ electrodes (68.8 F g^–1). The charge transfer resistance (R_ct) of 3D-PbO₂ electrodes (8.21 Ohm cm^–2) is lower than that of Flat-PbO₂ electrodes (21.32 Ohm cm^–2). The excellent supercapacitive performance of 3D-PbO₂ electrodes can be attributed to the three-dimensional porous structure, which can enlarge the active surface area of lead dioxide electrodes and promote the electrolyte diffusion and electrons propagation.