摘要
Porous carbons （PC） were prepared from a waste biomass named chestnut shell via a two-step method involving carbonization and KOH activation. The morphology, pore structure and surface chemical properties were investigated by scanning electron microscopy （SEM）, N2 sorption, Raman spectroscopy, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. The carbons have been evaluated as the electrode materials for supercapacitors by a two-electrode system in 6 mol/L KOH electrolyte. Benefiting from the porous texture, high surface area and high oxygen content, the PCs derived from chestnut shell have exhibited high specific capacitance of 198.2 （PC-l）, 217.2 （PC-2） and 238.2 F·g^-1 （PC-3） at a current density of 0.1 Aog l, good rate capability of 55.7%, 56.6% and 54.9% in a range of 0.1 -20 A·g^-1 and high energy density of 5.6, 6.1 and 6.7 Wh·kg^-1, respectively. This is believed to be due to electric double layer capacitance induced by the abundant micropores and extra pseudo-capacitance generated by oxygen-containing groups. At a power density of 9000 Wh·kg^-1, the energy density is 3.1, 3.5 and 3.7 Whokg 1 for PC-l, PC-2 and PC-3, respectively, demonstrating the potential of the carbons derived from chestnut shells in energy storage devices.
Porous carbons （PC） were prepared from a waste biomass named chestnut shell via a two-step method involving carbonization and KOH activation. The morphology, pore structure and surface chemical properties were investigated by scanning electron microscopy （SEM）, N2 sorption, Raman spectroscopy, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. The carbons have been evaluated as the electrode materials for supercapacitors by a two-electrode system in 6 mol/L KOH electrolyte. Benefiting from the porous texture, high surface area and high oxygen content, the PCs derived from chestnut shell have exhibited high specific capacitance of 198.2 （PC-l）, 217.2 （PC-2） and 238.2 F·g^-1 （PC-3） at a current density of 0.1 Aog l, good rate capability of 55.7%, 56.6% and 54.9% in a range of 0.1 -20 A·g^-1 and high energy density of 5.6, 6.1 and 6.7 Wh·kg^-1, respectively. This is believed to be due to electric double layer capacitance induced by the abundant micropores and extra pseudo-capacitance generated by oxygen-containing groups. At a power density of 9000 Wh·kg^-1, the energy density is 3.1, 3.5 and 3.7 Whokg 1 for PC-l, PC-2 and PC-3, respectively, demonstrating the potential of the carbons derived from chestnut shells in energy storage devices.
基金
We are grateful for the financial support from the National Natural Science Foundation of China （Nos. 21402108, 21476132, 51302156 and 21576158）, the Natural Science Foundation of Shandong Province （No. ZR2014BQ036） and the Young Teacher Supporting Fund of Shandong University of Technology.
