超级电容器用煤基多孔碳改性研究进展  

Advances in the modification of coal-based porous carbon for supercapacitors

作　　者：吴小燕 秦志宏[1] 杨小芹[1] 林喆[1] WU Xiaoyan;QIN Zhihong;YANG Xiaoqin;LIN Zhe(School of Chemical Engineering and Technology,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学化工学院,江苏徐州221116

出　　处：《洁净煤技术》2022年第1期94-102,共9页Clean Coal Technology

基　　金：国家自然科学基金资助项目(51674260,21706276)。

摘　　要：煤炭因其碳含量高、储量丰富及价格低廉,成为优质的多孔碳碳前驱体。以煤炭为原料制备超级电容器用多孔电极材料是实现煤炭高附加值利用的重要方向之一。通过调整孔结构、改善表面化学活性均能有效提高煤基多孔碳电极材料的电化学性能,其中调整孔径分布可利用物理活化和化学活化联合、模板法和化学活化联合以及不同化学活化剂联合3种方法。物理活化和化学活化联合法主要是通过水蒸气或CO_(2)对KOH活化过程进行辅助,在得到大量微孔的同时获得一定量的介孔,并实现煤基多孔碳孔隙与润湿性的协同调控。模板法与化学活化联合则可在获得与模板剂相同孔结构的同时,通过KOH活化进一步造出丰富微孔,从而实现合理的孔径分布。除使用模板剂外,也可利用碳前驱体自身含有的大量杂质充当自模板。采用不同化学活化剂联合的方法也能实现孔结构的调节,如K^(+)和Na^(+)的离子尺寸不同,联合利用可得到不同的孔径分布;利用KCl在高温下的流动性,可以将KOH的中间产物带入更广范围和更深层次,从而实现微孔向介孔的转化。改善表面化学活性则可通过炭前驱体预氧化和引入杂原子2种方式。通过强酸或强氧化剂对原煤进行预处理,可以提高所制备碳材料的有机氧含量,增加活性位点并提高润湿性。通过掺杂剂掺杂可在碳材料中引入杂原子,其中应用最多的是N掺杂,所引入的含氮结构包括吡咯-N(N-5)、吡啶-N(N-6)、季铵-N(N-Q)和氧化-N(N-X)4种。此外,O、B、S和P也是常见的掺杂原子。另一种引入杂原子的方法是通过煤与生物质共碳化,此时生物质既充当碳源也充当杂原子源。杂原子掺杂可改善碳材料的润湿性、导电性和结构稳定性,并可产生一定量的赝电容。从以上方面综述了近几年来煤基多孔碳电极材料的研究进展,分析了不同改性方法的优缺点,并对目Coal is a promising carbonaceous precursor for high-quality porous carbon because of its high carbon content,abundant reserves and low price.The preparation of porous electrode materials for supercapacitors from coal is one of the important routes to realize the high value-added utilization of coal.The results show that the electrochemical properties of coal-based porous carbon electrode materials can be effectively improved by adjusting the pore structure and improving the surface chemical activity.The pore size distribution can be adjusted by three methods:physical and chemical co-activation,template method combined with chemical activation and combination of different chemical activators.The combined physical activation and chemical activation method mainly uses water vapor or CO_(2) to assist the activation process of KOH,so as to obtain a large number of micropores and a certain amount of mesoporous pores,and realize the synergistic control of the pore structure and wettability of coal-based porous carbon.The combination of template method and chemical activation can obtain the same pore structure as template agent,and at the same time,KOH activation can further produce abundant micropores,thus achieving reasonable pore size distribution.In addition to using template agent,a large number of impurities contained in the carbon precursor can also be used as self-template.The adjustment of pore structure can also be realized by combining different chemical activators.For example,different pore size distribution can be obtained by combining K^(+) and Na^(+) ions with different ionic sizes.Using the fluidity of KCl at high temperature,the intermediate products of KOH can be carried to a wider and deeper extent,so as to realize the transformation from microporous to mesoporous.The surface chemical activity can be improved in 2 ways:by the pre-oxidation of carbon precursors and the introduction of heteroatoms.If the raw coal is pretreated by strong acid or strong oxidant,the organic oxygen content of the prepared ca

关 键 词：煤基 超级电容器 电极材料 多孔碳 改性方法 

分 类 号：TQ152[化学工程—电化学工业]