Polypyrrole-covered MnO2 as electrode material for supercapacitor

• Published in: Journal of power sources 2013, Vol.240, p.267-272
• Main Authors: Bahloul, A., Nessark, B., Briot, E., Groult, H., Mauger, A., Zaghib, K., Julien, C.M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Asymmetry; Capacitance; Capacitors. Resistors. Filters; Chemistry; Coating; Current density; Electrical engineering. Electrical power engineering; Electrochemistry; Electrode materials; Electrodeposition; Electronics; Exact sciences and technology; General and physical chemistry; General Physics; Manganese dioxide; Materials; Physics; Polymerization; Polypyrrole; Pyrroles; Study of interfaces; Super-capacitors; Various equipment and components
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.04.013

γ-MnO2 has been synthesized by hydrothermal process, and studied as electrode material in aqueous asymmetric super-capacitor. We studied the blend formed by electrochemical polymerization of pyrrole deposited onto γ-MnO2 particles. The composite materials (PPy/MnO2) were characterized by different methods including cyclic voltammetry, chronoamperometry, X-ray diffractometry and BET measurements. The specific capacitance at constant current density 2 mA cm−2 was calculated from galvanostatic charge-discharge cycling tests. The asymmetric super-capacitor using (PPy/MnO2) composite material has high specific capacitance of 141.6 F g−1 compared with 73.7 F g−1 for γ-MnO2 before PPy coating. The improvement of the coating is not only due to the electronic conductivity of the polymer, but also due to an increase of the BET surface area that raises to 125 m2 g−1 after coating, against 64 m2 g−1 for pristine MnO2. •γ-MnO2 as hybrid electrode material in aqueous asymmetric super-capacitor.•Blend formed by electrochemical polymerization of pyrrole monomer (PPy).•Enhancement of the specific capacitance by a factor 2 for PPy/MnO2 electrode.