Nanostructured composite electrode based on hydrous manganese oxide and mesoporous carbon for electrochemical supercapacitor: Synthesis, morphology, electrochemical characterization

MnO2/C composites electrodes are synthesized by two different methods: chemical reduction and electrochemical deposition. The morphology and structure of samples are examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. Electrochemical properties are characterized by cyclic voltammetry (CV) in aqueous 2M NaCl. -MnO2 structure were obtained for all samples. In chemical reduction, the carbon addition improves specific capacitance (SP) as well as the specific surface area (SSA). The highest value was reached at 30% carbon content. The effect of carbon nature was also studied, such as C black, C super P and C Vulcan XC-72R. The electrochemical deposition of MnO2 was investigated on graphite substrate (EMD) and modified graphite substrate (EMD-2L) by two layers of hydrophobic and hydrophilic. The electrodes exhibited the good cyclic performance (< 5% capacity loss after 300 cyles) and good specific capacitance (375 F.g-1 as to 240 F.g-1 at 1 mV.s-1)