文摘
In this paper, cabbage leaves (CLs) were used to synthesize porous activated carbon by the carbonization and activation processes. The material for CLs were carbonized at 600 °C and activated at 800 °C with the KOH/C-600 mass ratio 4 (denoted as AC-800) show typical amorphous character and display porous structures with high specific surface areas 3102 m2/g via XRD and BET measurements. As the electro-active material, AC-800 electrode exhibit ideal capacitive behaviors in aqueous electrolytes and the maximal specific capacitance is as high as 336 F/g at the current density of 1 A/g. Furthermore, AC-800 electrode shows excellent electrochemical cycle stability with ∼95 % initial capacitance being retained after 2000 cycles. The desirable capacitive performances enable the CLs to act as a new biomass source of carbonaceous materials for high-performance supercapacitors and low-cost electrical energy storage devices.