− 72 − Journal of Electrochemical Science and Technology Synthesis and Performance of Li2MnSiO4 as an Electrode Mate- rial for Hybrid Supercapacitor Applications

Li2MnSiO4 was synthesized using the solid-state method under an Ar atmosphere at three different calcination temperatures (900, 950, and 1000oC). The optimization of the carbon coating was also carried out using various molar concentrations of adipic acid as the carbon source. The XRD pattern confirmed that the resulting Li2MnSiO4 particles exhibited an orthorhombic structure with a Pmn21 space group. Cyclic voltammetry was utilized to investigate the capacitive behavior of Li2MnSiO4 along with activated carbon (AC) in a hybrid supercapacitor with a two-electrode cell configuration. The Li2MnSiO4/AC cell exhibited a high discharge capacitance and energy density of 43.2 Fg −1 and 54 Whkg−1, respectively, at 1.0 mAcm−2. The Li2MnSiO4/AC hybrid supercapacitor exhibited an excellent cycling stability over 1000 measured cycles with coulombic efficiency over> 99 %. Elec-trochemical impedance spectroscopy was conducted to corroborate the results that were obtained and described