National Research Council of Canada. Energy, Mining and Environment
Capacitors; Chemical compounds; Cyclic voltammetry; Electrochemical electrodes; Electrochemical properties; Electrodes; Electrolytes; Electrolytic capacitors; Inorganic compounds; Manganese; Manganese oxide; Synthesis (chemical); X ray diffraction; Coulombic efficiency; Discharge capacities; Electrochemical performance; Electrochemical techniques; Galvanostatic charge discharges; High specific capacity; Impedance measurement; Solvothermal synthesis; Electric discharges
The layered sodium manganese oxides Na0.7MnO2.05 material was synthesized using Na2CO3 and Mn3O4 precursors via a solvothermal method at different temperatures. The X-ray diffraction (XRD) shows that the Na0.7MnO2.05 sample has a high crystallinity with hexagonal crystal system. The electrochemical performance was characterized by cyclic voltammetry (CV), impedance measurements and galvanostatic charge-discharge tests in symmetric Na-ion supercapacitors with 1 mol L-1 Na2SO4 solution as electrolyte. The Na0.7MnO2.05 material shows a high specific capacity of about 162.5 F g-1 at a current density of 50 mA g-1 and a high coulombic efficiency approaching 100%. Even at a current density of 200 mA g-1, the discharge capacity of the material can reach to 146 F g-1. This electrode material holds great promise for practical applications.
Materials Chemistry and Physics (17 December 2015).