Slepchenkov Michael M, Barkov Pavel V, Glukhova Olga E
Institute of Physics, Saratov State University, 410012 Saratov, Russia.
Laboratory of Biomedical Nanotechnology, I.M. Sechenov First Moscow State Medical University, 119991 Moscow, Russia.
Membranes (Basel). 2021 Aug 26;11(9):658. doi: 10.3390/membranes11090658.
Using the self-consistent-charge density-functional tight-binding (SCC-DFTB) method, we studied the effect of axial stretching on the electrical conductivity and quantum capacitance of hybrid films formed by AB-stacked bilayer graphene and horizontally oriented single-walled carbon nanotubes (SWCNTs) with indices chirality (12, 6). The paper discusses several topological models of hybrid graphene/SWCNT (12, 6) films, which differ in the width of the graphene layer in the supercell and in the value of the shift between the graphene layers. It is shown that axial stretching has a different effect on the electrical conductivity and quantum capacity of the hybrid graphene/SWCNT (12, 6) film depending on the width of the graphene layer. For a topological model with a minimum width of the graphene layer (2 hexagons) under a 10% stretching strain, the transformation of bilayer graphene from planar to wave-like structures is characteristic. This transformation is accompanied by the appearance of the effect of anisotropy of electrical conductivity and a sharp decrease in the maximum of quantum capacitance. For a topological model with a graphene layer width of 4 hexagons, axial stretching, on the contrary, leads to a decrease in the effect of anisotropy of electrical conductivity and insignificant changes in the quantum capacitance. Based on the obtained results, the prospects for using hybrid graphene/SWCNT (12, 6) films as a material for creating flexible electrodes of supercapacitors are predicted.
我们使用自洽电荷密度泛函紧束缚（SCC-DFTB）方法，研究了轴向拉伸对由AB堆叠双层石墨烯和具有指数手性（12, 6）的水平取向单壁碳纳米管（SWCNT）形成的混合薄膜的电导率和量子电容的影响。本文讨论了几种石墨烯/ SWCNT（12, 6）混合薄膜的拓扑模型，这些模型在超晶胞中石墨烯层的宽度以及石墨烯层之间的位移值方面存在差异。结果表明，根据石墨烯层的宽度，轴向拉伸对石墨烯/ SWCNT（12, 6）混合薄膜的电导率和量子电容有不同的影响。对于石墨烯层宽度最小（2个六边形）的拓扑模型，在10％的拉伸应变下，双层石墨烯从平面结构转变为波状结构是其特征。这种转变伴随着电导率各向异性效应的出现以及量子电容最大值的急剧下降。对于石墨烯层宽度为4个六边形的拓扑模型，相反，轴向拉伸导致电导率各向异性效应的降低以及量子电容的微小变化。基于所得结果，预测了使用石墨烯/ SWCNT（12, 6）混合薄膜作为制造超级电容器柔性电极材料的前景。
