The development of supercapacitors from coconut-shell activated carbon

In an attempt to develop small high-power supercapacitors a 1 V-70 F,9 cm~(3),coin-shaped supercapacitor was fabricated using coconut-shell activated carbon with a surface area of 1 660 m~(2)/g and 6 mol/L KOH as the electrolyte.The outer package was made from laminated aluminum foil covered with a nylon insulating layer.The electrochemical behavior was measured by constant current charge/discharge and electrochemical impedance spectroscopy.A specific capacitance of 79 F/g was obtained.Results show that a specific power density of(170 W/kg) or 330 W/L,and a specific energy density of 1 Wh/kg can be reached with an excellent discharge performance under high current density.