Preparation of biomass-activated porous carbons derived from torreya grandis shell for high-performance supercapacitor

In this paper, we reported a novel biomass-derived porous carbon from torreya grandis shell for the first time by means of carbonization and KOH activation under N-2. The pore structures were related to the ratio of KOH and activation temperature. N-2 adsorption-desorption tests indicated that the sample of AC-800-3 has a maximum specific surface area of 2100.8 m(2) g(-1) and proper pore volume of 1.02 cm(3) g(-1). The electrode prepared with AC-800-3 realized a high capacitance of 290.5 F g(-1) at 0.5 A g(-1) and excellent rate capability of 62.6% in three-electrode system. The assembled symmetrical cell of AC-800-3 electrode exhibited a high energy density of 13.5 W h kg(-1) at a power density of 360.1 W kg(-1) in the potential range of 0-1.6 V and excellent cycling stability with 93.1% retention of the initial capacitance after 5000 cycles.