Symmetric electrochemical capacitor based on PPy obtained via MnO2 reactive template synthesis

The present work explores the synthesis of sulphate-polypyrrole (PPy/SO42-) using MnO2 as a reactive template. Samples were characterized by different techniques, including SEM, CHNS, XRD, and XPS, which confirmed that MnO2 acted as a reactive template during PPy synthesis. The materials obtained were characterized by cyclic voltammetry and electrochemical impedance spectroscopy techniques to evaluate their electrochemical properties as electrodes for electrochemical capacitors (ECs electrodes). Py50/M50 electrode exhibited the highest specific capacitance value being 1215 mF cm(-2) (or 125 F g(-1)) at 5 mV s(-1). According to PEIS analysis, the enhancement of capacitive performance is attributed to the elongated shape morphology of Py50/M50 electrode that improves the ionic diffusion and reduces the charge transfer resistance on its surface. Furthermore, a symmetric ECs assembly using two identical pieces of Py50/M50 electrodes exhibited a maximum areal energy and power density of 13.5 mW h cm(-2) and 324 mW cm(-2), respectively. These results suggest a new route of synthesis of PPy/SO4(2-) with elongated shape morphology to produce electrodes for ECs with high electrochemical performance.