Ba Yuerong, Pan Wei, Pi Shangchao, Zhao Yaomin, Mi Liwei
School of Materials and Chemical Engineering, Zhongyuan University of Technology Zhengzhou 451191 PR China
Center for Advanced Materials Research, Zhongyuan University of Technology Zhengzhou 451191 PR China
RSC Adv. 2018 Feb 14;8(13):7072-7079. doi: 10.1039/c8ra00016f. eCollection 2018 Feb 9.
Nitrogen-doped hierarchical porous carbon (NHPC) materials were synthesized by using a chitosan/polyethylene glycol (PEG) blend as raw material through a facile carbonization-activation process. In this method, chitosan was used as a nitrogen-containing carbon precursor, low cost and large-scale commercial PEG was employed as a porogen. The physical and electrochemical properties of the resultant NHPC were affected by the ratio of chitosan and PEG. The sample obtained by the ratio of 3 : 2 exhibits a high specific surface area (2269 m g), moderate nitrogen doping (3.22 at%) and optimized pore structure. It exhibits a high specific capacitance of 356 F g in 1 M HSO and 271 F g in 2 M KOH at a current density of 1 A g, and over 230 F g can be still retained at a high current density of 20 A g in both electrolytes. Additionally, the assembled symmetric supercapacitors show an excellent cycling stability with 94% (in 1 M HSO) and 97% (in 2 M KOH) retention after 10 000 cycles at 1 A g. These results indicate that the chitosan/PEG blend can act as a novel and appropriate precursor to prepare low-cost NHPC materials for high-performance supercapacitors.
以壳聚糖/聚乙二醇（PEG）共混物为原料，通过简便的碳化-活化工艺合成了氮掺杂分级多孔碳（NHPC）材料。在该方法中，壳聚糖用作含氮碳前驱体，低成本且大规模商业化的PEG用作造孔剂。所得NHPC的物理和电化学性能受壳聚糖与PEG比例的影响。壳聚糖与PEG比例为3∶2时获得的样品具有高比表面积（2269 m²/g）、适度的氮掺杂（3.22 at%）和优化的孔结构。在1 A/g的电流密度下，其在1 M H₂SO₄中比电容为356 F/g，在2 M KOH中为271 F/g，在两种电解质中，当电流密度为20 A/g时仍可保持超过230 F/g。此外，组装的对称超级电容器在1 A/g下循环10000次后表现出优异的循环稳定性，在1 M H₂SO₄中电容保持率为94%，在2 M KOH中为97%。这些结果表明，壳聚糖/PEG共混物可作为一种新型且合适的前驱体，用于制备低成本的NHPC材料以用于高性能超级电容器。
