Converting eucalyptus leaves into mesoporous carbon for its application in quasi solid-state supercapacitors

A high performance activated carbon having pore diameter of 2.8 nm and specific surface area of 841.8 m(2) g(-1) is prepared by chemical activation of eucalyptus leaves using KOH as an activating agent. The chemically-treated eucalyptus leaves EL(T) as electrode material has a specific capacitance of 663.5 mF cm(-2) (equivalent to single electrode specific capacitance of 442.3 F g(-1)) with solid polymer electrolyte. This active material has excellent rate capability and good cycle performance, over 95 % of the original capacitance is retained after 5,000 cycles. The energy density of 101.6 Wh kg(-1) and power density of 2.85 kW kg(-1) has been observed for EL(T) based quasi solid-state supercapacitors.