Electrochemical Properties and Capacitive Performance of Polypyrrole-Manganese Dioxide Composite Electrodes for Supercapacitors

International Journal of Chemistry | Vol. 6, No. 3, March 2015 | pp. 17–24

DOI: 10.46882/2015/IJC/000078

Article Type: Original Research Paper

Title: Electrochemical Properties and Capacitive Performance of Polypyrrole-Manganese Dioxide Composite Electrodes for Supercapacitors

Names of Authors: U. B. Aliyu¹, K. N. S. Tan²*

Authors’ Affiliations:
¹Department of Chemistry, Ahmadu Bello University, Zaria, Nigeria.
²Department of Chemistry, National University of Singapore, Singapore.

Abstract: The fabrication of hybrid electrochemical capacitors requires electrode configurations that successfully merge high pseudocapacitive charge transfer with structural network longevity. This research outlines the synthesis and supercapacitive performance of polypyrrole-manganese dioxide (PPy-MnO₂) nanocomposites prepared via the in situ chemical oxidative polymerization of pyrrole monomers in the presence of hydrothermally prepared MnO₂ nanorods. The microstructural morphology and chemical networks of the composite films were analyzed using field emission scanning electron microscopy (FESEM), FT-IR, and Raman spectroscopy. FESEM images confirmed the uniform encapsulation of a thin amorphous PPy layer around the highly crystalline MnO₂ nanorods. Electrochemical characterization was carried out in a three-electrode system using a 1.0 M Na₂SO₄ electrolyte via cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) cycles. The optimized PPy-MnO₂ composite electrode delivered a maximum specific capacitance of 435 F/g at a current density of 1.0 A/g, outperforming standalone pure polypyrrole (210 F/g). Electrochemical impedance spectroscopy (EIS) data showed a low internal charge-transfer resistance of 0.42 ohms, and cyclic evaluations proved that the electrode retained 88.4% of its capacitance after 2000 continuous cycles.

Keywords: Polypyrrole; Manganese dioxide; Nanocomposites; Supercapacitors; Cyclic voltammetry; Specific capacitance

Manuscript Timeline: Received: May 02, 2014; Revised: June 15, 2014; Accepted: July 12, 2014; Published: March 04, 2015.

Citation: Aliyu, U. B., & Tan, K. N. S. (2015). Electrochemical Properties and Capacitive Performance of Polypyrrole-Manganese Dioxide Composite Electrodes for Supercapacitors. International Journal of Chemistry, 6(3), 17–24.

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