香菇生物质基氮掺杂微孔碳材料的制备及其在超级电容器中的应用

采用简易浸泡法和一步碳化/活化法制备香菇生物质基氮掺杂微孔碳材料(NMCs),利用扫描电子显微镜(SEM)、透射电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)对材料的结构形貌进行表征,并研究了其超级电容特性。测试结果表明,NMCs的微孔比表面积高达1 594 m~2·g~(-1),且拥有更高数量的含氮官能团,其吡啶型含氮官能团比例也有所提高,展现出优异的超级电容特性。在0.5 A·g~(-1)的电流密度下,其比容量高达325 F·g~(-1),当电流密度上升到20 A·g~(-1)时,其比电容仍然高达180 F·g~(-1),表现出优异的倍率性能;同时,在5 A·g~(-1)的电流密度下,电极经历5 000次充放电循环后具有97.7%的比容量保持率,展现出优异的循环稳定性。这主要归因于NMCs超高的微孔比表面积和丰富的含氮官能团。

Preparation and Application in Supercapacitors of Shiitake Biomass-Based Nitrogen-Doped Microporous Carbon

Shiitake-derived nitrogen-doped microporous carbon materials were prepared by a simple activation/carbonization process. It was found that the nitrogen content was enhanced owing to the consumption of carbon in the activation process, and that the pyridinic nitrogen groups were promoted after activation. The microporous carbons offered a high specific surface area of 1 930 m²·g^-1 with a high micropore surface area of 1 594 m²·g^-1. The high micropore surface area accompanied with rich nitrogen and oxygen groups contributed to a remarkable specific capacitance of 325 F·g^-1 at 0.5 A·g^-1 and high rate capability. In addition, shiitake-derived microporous carbons presented robust cycling stability with 2.3% capacitance loss during 5 000 cycles, and a high specific capacitance of 203 F·g^-1 at 0.5 A·g^-1 in symmetric supercapacitors. The high performance could be attributed to the high surface area, enhancing electric double layer capacitance, and numerous nitrogen groups.