Facile Synthesis of Layered Sodium Manganese Oxide for Application in Asymmetric Supercapacitor

Layered sodium manganese oxides (LSMOs), with two-dimensional channels for ion diffusion, have been regarded as the promising electrode materials in the application of asymmetric supercapacitors (ASCs). In this work, the layered Na0.5Mn2O4 center dot 1.5H(2)O was synthesized through a facile hydrothermal method by controlling the molar ratio of sodium and manganese. When the molar ratio of sodium to manganese is 3:1, Na0.5Mn2O4 center dot 1.5H(2)O has shown the best capacitance of 369 F/g with current density of 0.5 A/g, and maintained a capacitance of 265 F/g after 2000 cycles. The asymmetric supercapacitor consists of the sodium manages oxides as the positive electrode and active carbon (AC) as the negative electrode in 1 mol/L Na2SO4 solution. The voltage of the asymmetric supercapacitor has been expanded to 0 similar to 2 V with an energy density of 10.13 Wh/kg at a power density of 500 W/kg based on the total weight of both active electrode materials when the mass ratio of AC to Na0.5Mn2O4 center dot 1.5H(2)O was 3:1.