The capacitance properties of activated carbon obtained from chitosan as the electrode material for electrochemical capacitors

Porous carbon was prepared through KOH activation of a chitosan - a nitrogen rich precursor. The porosity and surface area strongly depend on the temperature of activation. Different electrolytes were tested to select the most suitable one for electrochemical capacitors with obtained activated carbon as electrode material, and the acidic medium, i.e. 1 M H2SO4 was chosen. The activated carbon prepared with the temperature of activation standing at 750 °C exhibits the largest specific surface area and capacitance of 295 F g−1 at a current density of 0.1 A g−1 in the acidic medium. Moreover, the activated carbon from chitosan shows good rate capability and excellent cycling stability (almost 99% capacitance retention over 5000 cycles).