Preparation of oxygen-rich hierarchical porous carbon for supercapacitors through the co-carbonization of pitch and biomass
Preparation of oxygen-rich hierarchical porous carbon for supercapacitors through the co-carbonization of pitch and biomass
复制标题
沥青与生物质共碳化制备超级电容器用富氧分级多孔碳
DOI：
10.1016/j.diamond.2019.04.036
复制
发表时间：
2019-06-01
影响因子：
4.1
通讯作者：
Li, Xuanke
中科院分区：
文献类型：
--
作者：
Cao, Shuo;Yang, Jianxiao;Li, Xuanke
以中间相沥青（MP）和生物质锯末（BS）为原料，经KOH活化后共炭化，成功制备了富氧分级多孔炭（PC）。由于BS具有分级多孔结构和丰富的杂原子，PC具有高比表面积和表面大量的氧官能团。此外，由于MP具有大量的多核芳香结构单元，易于形成石墨化结构，因此PC具有高的石墨化度。结果表明，以MP和BS的质量比为5：5共炭化制得的PC-5/5具有较高的含氧官能团（Boehm滴定法测得C-OH为1.43 mmol/g，RO-C=O为0.65 mmol/g，O-C= O为0.66 mmol/g），比表面积达到2361 m2/g。作为超级电容器的电极材料，在6 mol/LKOH电解液中，当电流密度为0.5A/g时，PC-5/5电极的比电容达到324 F/g。当电流密度从0.5 A/g增加到5 A/g时，该电极的留存率为75%，并且在500次循环后仍保持95%的容量。因此，通过MP和BS共碳化得到的PC具有作为电极材料的高潜力。该路线不仅提高了生物质废弃物的效益，而且降低了超级电容器电极材料的生产成本。
Oxygen-rich hierarchical porous carbons (PCs) were successfully prepared through the co-carbonization of mesophase pitch (MP) and biomass sawdust (BS), following KOH activation. The PCs possessed a high specific surface area and a considerable amount of oxygen functional groups on the surface due to BS containing hierarchical porous structures and an abundant of heteroatoms. Moreover, the PCs exhibited high graphitization degree due to MP with a great deal of polynuclear aromatic structural units for easily forming the graphitized structures. The results showed that the PC-5/5 obtained from the co-carbonization of MP and BS with weight ratio of 5/5 had a high oxygen functional groups (1.43 mmol/g C-OH, 0.65 mmol/g RO-C=O, 0.66 mmol/g O-C=O from Boehm titration results) and its surface area reached to 2361 m(2)/g. As an electrode material for supercapacitor, the prepared electrode from PC-5/5 exhibited a favorable specific capacitance of 324 F/g at a current density of 0.5 A/g in 6 mol/L KOH electrolyte. The electrode also demonstrated excellent rate ability with a retention rate of 75% when the current density increases from 0.5 to 5 A/g, and remained 95% of the capacitance at 5 A/g after 500 cycles. Therefore, the PCs obtained by co-carbonization of MP and BS have high potential as electrode materials. This route not only enhanced the benefit from biomass wastes, but also reduced the cost of producing electrode materials for supercapacitor.