用于高性能超级电容器电极的栓皮栎基多孔活性炭的制备

本研究以空腔细胞组成的栓皮栎为原料, KOH为活化剂制备了具有多孔结构的栓皮栎软木基多孔活性炭。以此方法制得的活性炭呈薄片状外形, 最大比表面积达到2312 m ²/g, 具有特殊的微孔-介孔结构。在呈碱性的KOH三电极体系中, 0.1 A/g电流密度时比电容达296 F/g; 两电极体系中, 5 A/g时的比电容达到201 F/g, 循环5000次后电容保持率达99.5%。在呈中性的Na₂SO₄两电极体系中, 电流密度0.5 A/g (174 F/g)至50 A/g (140 F/g)时电容保持率达80.5%, 倍率性能良好, 能量密度高达19.62 Wh/kg。

Preparation of Cork-derived Porous Activated Carbon for High Performance Supercapacitors

The quercus variabilis cork made up of cavity cells is used as raw material. Herein, the cork-derived activated carbon with the various pores was successfully prepared by the facile carbonization of cork followed by chemical activation. The as-prepared activated carbon sheets possess large specific surface area (2312 m ²/g) and unique interconnected pores. As a result, it shows excellent electrochemical performance as electrode material for supercapacitors. In three electrode system of KOH, it exhibits a high specific capacitance of 296 F/g at a current density of 0.1 A/g. The assembled symmetric supercapacitor shows a high specific capacitance of 201 F/g at 5 A/g, with a good cycling stability of 99.5 % capacitance retention after 5000 cycles. In two electrode system of Na₂SO₄, the symmetric supercapacitor displays a good rate performance of 80.5% retention from 0.5 A/g (174 F/g) to 50 A/g (140 F/g) and a high energy density of 19.62 Wh/kg.