For example, the C atomic concentration of MC by hydrothermal carbonization reduced from 91.72 to 90.62 %, while by direct pyrolysis method it was reduced from 88.58 to 75.02%, which indicates that the storage years of moxa floss and pre-carbonization greatly regulates the surface composition of MC. The electrochemical performances of MC as the electrode materials for supercapacitors were evaluated in a symmetric two-electrode system using 6 M KOH aqueous solution electrolyte. The assembled MC-5 supercapacitor in a two-electrode system with aqueous electrolyte, showed the maximum specific capacitance of 288.3 F g -1 at 0.25 A g -1 , and the long-term cycling stability with 98.7% of initial capacitance retention after 10000 charge-discharge cycles at 5 A g -1 . The MC based supercapacitors showed the maximum energy density of 70.3 Wh Kg -1 at a power density of 70.3 W Kg -1 , and the energy density were retained upto 6.0 W h Kg -1 even when the power density was increased upto 12.3 kW Kg -1 .