Effect of the Components of the Electrode on the Morphological and Electrochemical Performance of Manganese Dioxide-Based Electrode for Application in Hybrid Electrochemical Capacitor

Abstract

Composite electrodes based on manganese dioxide, a binder (poly(tetrafluoroethylene, PTFE) and a carbon additive (Acetylene black or high surface area Black Pearls 2000) were characterized by nitrogen gas adsorption. The electrochemical performances of the MnO2/Carbon/PTFE composite electrodes were evaluated by cyclic voltammetry. Brunauer–Emmett–Teller (BET) surface area measurements indicated only a minor effect of acetylene black (AB) on the mesoporous surface of composite electrode, presumably because of its larger particle size compared to Black Pearls 2000 (BP). The electrochemical utilization of MnO2 is similar whether AB or BP is used as carbon additive. This suggests that the porosity of Black Pearls, which could perhaps act as a reservoir of ionic species, does not appear to play a significant role. Finally, using a high surface carbon support with MnO2 can cancel the effect of the larger potential window of electroactivity of MnO2 because of its smaller electrochemical potential stability range.

Influence of carbon substrate on the electrochemical performance of carbon/manganese oxide hybrids in aqueous and organic electrolytes

“…Much higher values have also been published, 49 for example, up to 1380 F g À1 for thin lms (5 mm) 46 in the same order of magnitude than the maximum theoretical value of 1233 F g À1 . 50 The electrochemical performance of manganese oxide is not only determined by its morphology, phase, composition, and crystal structure, 51,52 but also by thickness of the electrode/coating/particles. 46,53 Although manganese oxide as supercapacitor material is already extensively studied, for example, by the groups of D. Bélanger, T. Brousse, and F. Favier, 46,48,51,[54][55][56][57][58][59][60][61][62][63] remaining challenges are its low structural stability, low long-time stability, small negative voltage stability, high self-discharge, and poor electrical conductivity.…”