Synthesis, characterization, and enhanced electrochemical behavior of polypyrrole doped ZrO₂–ZnO electrode materials for supercapacitor applications

The polypyrrole@ZrO₂–ZnO (PPy@ZrO₂–ZnO) electrodes were synthesized using an in situ chemical oxidative method. The samples were characterized by XRD, FTIR, XPS, UV-vis, TGA, and BET. In addition, the electrochemical characteristics of the electrodes are tested by cyclic voltammetry (CV), galvanostatic charge and discharge (G.C.D.), and electrochemical impedance spectroscopy (E.I.S.). The values of the specific capacitances and the energy densities of PPy@ZrO₂–ZnO (1.0) and PPy@ZrO₂–ZnO (0.5) at a current density of 0.5 A g⁻¹ are recorded as (395.3 F g⁻¹ and 508.5 Wh·kg⁻¹) and (195.3 F g⁻¹ and 351.5 Wh·kg⁻¹), respectively. Furthermore, the electrode stability for the formed samples was also determined, which exhibited specific capacitance retention at 90.2% for PPy@ZrO₂–ZnO (1.0) and 82.4% for PPy@ZrO₂–ZnO (0.5) after cycling up to 4,000 cycles. This work provides an efficient approach to the potential of the synthesized samples for application as electrodes in a supercapacitor.