Chen Hui, Wang Gang, Chen Long, Dai Bin, Yu Feng
Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China.
Key Laboratory of Materials-Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region, Shihezi 832003, China.
Nanomaterials (Basel). 2018 Jun 8;8(6):412. doi: 10.3390/nano8060412.
Hierarchical porous structures with surface nitrogen-doped porous carbon are current research topics of interest for high performance supercapacitor electrode materials. Herein, a three-dimensional (3D) honeycomb-like porous carbon with interconnected hierarchical porosity and nitrogen self-doping was synthesized by simple and cost-efficient one-step KOH activation from waste cottonseed husk (a-CSHs). The obtained a-CSHs possessed hierarchical micro-, meso-, and macro-pores, a high specific surface area of 1694.1 m²/g, 3D architecture, and abundant self N-doping. Owing to these distinct features, a-CSHs delivered high specific capacitances of 238 F/g and 200 F/g at current densities of 0.5 A/g and 20 A/g, respectively, in a 6 mol/L KOH electrolyte, demonstrating good capacitance retention of 84%. The assembled a-CSHs-based symmetric supercapacitor also displayed high specific capacitance of 52 F/g at 0.5 A/g, with an energy density of 10.4 Wh/Kg at 300 W/Kg, and 91% capacitance retention after 5000 cycles at 10 A/g.
具有表面氮掺杂多孔碳的分级多孔结构是当前高性能超级电容器电极材料的研究热点。在此，通过简单且经济高效的一步KOH活化法，以废弃棉籽壳（a-CSHs）为原料合成了具有相互连接的分级孔隙率和氮自掺杂的三维（3D）蜂窝状多孔碳。所制备的a-CSHs具有分级的微孔、介孔和大孔，比表面积高达1694.1 m²/g，具有三维结构以及丰富的自氮掺杂。由于这些独特的特性，在6 mol/L KOH电解液中，a-CSHs在电流密度为0.5 A/g和20 A/g时分别具有238 F/g和200 F/g的高比电容，显示出84%的良好电容保持率。组装的基于a-CSHs的对称超级电容器在0.5 A/g时也具有52 F/g的高比电容，在300 W/Kg时能量密度为10.4 Wh/Kg，在10 A/g下循环5000次后电容保持率为91%。
