J.D. Houck, V.S. Amar, A. Shende, R.V. Shende
South Dakota School of Mines and Technology,
Keywords: sol-gel synthesis, solvents, MnTi oxides, supercapacitor
Summary:Nanocomposites with varying amounts of Mn and Ti oxides were prepared using surfactant templating assisted sol-gel technique. Sol-A with Ti precursor and sol-B containing Mn precursor were individually prepared in ethanol containing 5-30 wt.% pluronic 123 surfactant. Gelation was accomplished by the addition of deionized water and catalyzed by dil. HCl. Gels were also prepared using the same precursors and solvents such as isopropanol and glacial acetic acid. The gels were aged for 24 hrs, dried at 80oC for 12 hrs and calcined at higher temperatures for several hours. These powdered electrode materials were analyzed by x-ray diffraction, BET surface area analysis and scanning electron microscopy. For the nanocomposite calcined at 500oC, both anatase and rutile phases along with Mn2O3 were observed. As calcination temperature increased, rutile and Mn2O3 phases were decreased. BET specific surface area (SSA) of >30 m2/g was observed for the powdered material calcined at 500oC. Supercapacitors were fabricated using these nanocomposites and cyclic voltammetry measurements were performed to infer specific capacitance. MnTi-oxides were doped with cobalt to improve performance of a supercapacitor. Synthesis and characterization of undoped and cobalt doped MnTi oxides and specific capacitance values will be presented.