新型炭材料2021，Vol.36Issue(6)：1062-1072,11.DOI:10.1016/S1872-5805(21)60079-3
双层堆叠对石墨烯材料量子电容影响的理论研究
A DFT study of the effect of stacking on the quantum capacitance of bilayer graphene materials
摘要
Abstract
Graphene is acknowledged as one of the ideal active electrode materials for electric double-layer capacitors because of its extremely high specific surface area and outstanding electronic conductivity. By introducing defects or heteroatoms into the graphene sheet, the electronic structure around the defects can be altered, which could lead to an increased quantum capacitance (CQ) and therefore te capacitive performance. One of the unavoidable problems for manufacturing and using graphene materials is that the stacking of the layers affects their electronic structure, and eventually their capacitance. DFT calculations were used to investigate the effect of layer stacking in bilayer graphene materials on CQ and the surface charge density. A two layer, AB-stacked graphene model, in which the top layer is defective and the bottom one is perfect was assumed for the calculations. The defective graphenes investig-ated are those containing Stone-Thrower-Wales defects, single vacancies (SV), three with double vacancies (5-8-5, 555-777 and 5555-6-7777), pyrrole-N graphene and the pyridine-N graphene. Results indicate that both the values and waveform of CQ of the ma-terials are changed by stacking. The CQ values of most of these graphenes are significantly increased after stacking. The CQ wave-forms of the SV and N-doped graphene are relatively insensitive to stacking. The basal layer contributes a considerable amount of charge, which is most obvious for the pyrrolic-N double-layer graphene and 5-8-5 double-vacancy graphene. The surface charge density provided by the defective top layer is increased by interlayer interaction, especially for the N-doped graphene. The uniform distribution of charge on the bottom layer partially alleviates fluctuations in the CQ waveform. These findings provide theoretical guidance for the micro-structural design of graphene materials to optimize their performance as electrode active materials.关键词
石墨烯/缺陷/量子电容/态密度/密度泛函理论Key words
Graphene/Defects/Quantum capacitance/Density of states/Density functional theory分类
化学化工引用本文复制引用
崔光宇,易宗琳,苏方远,陈成猛,韩培德..双层堆叠对石墨烯材料量子电容影响的理论研究[J].新型炭材料,2021,36(6):1062-1072,11.基金项目
中国科学院洁净能源创新研究院合作项目资助(DNL201915) （DNL201915）
2020年山西省关键核心技术和共性技术研发攻关专项(20201102018) （20201102018）
国家自然科学基金委员会优秀青年科学基金项目(21922815).This work was supported by The DNL Coopera-tion Fund,CAS(DNL201915),Research and Devel-opment Project of Key Core and Common Techno-logy of Shanxi Province(20201102018)and National Science Foundation for Excellent Young Scholars of china(21922815). （21922815）
