High Packing Density Unidirectional Arrays of Vertically Aligned Graphene with Enhanced Areal Capacitance for High-Power Micro-Supercapacitors.
Interfacial integration of a shape-engineered electrode with a strongly bonded current collector is the key for minimizing both ionic and electronic resistance and then developing high-power supercapacitors. Herein, we demonstrated the construction of high-power micro-supercapacitors (VG-MSCs) based on high-density unidirectional arrays of vertically aligned graphene (VG) nanosheets, derived from a thermally decomposed SiC substrate. The as-grown VG arrays showed a standing basal plane orientation grown on a (0001̅) SiC substrate, tailored thickness (3.5-28 μm), high-density structurally ordering alignment of graphene consisting of 1-5 layers, vertically oriented edges, open intersheet channels, high electrical conductivity (192 S cm-1), and strong bonding of the VG edges to the SiC substrate. As a result, the demonstrated VG-MSCs displayed a high areal capacitance of ∼7.3 mF cm-2and a fast frequency response with a short time constant of 9 ms. Furthermore, VG-MSCs in both an aqueous polymer gel electrolyte and nonaqueous ionic liquid of 1-ethyl-3-methylimidazolium tetrafluoroborate operated well at high scan rates of up to 200 V s-1. More importantly, VG-MSCs offered a high power density of ∼15 W cm-3in gel electrolyte and ∼61 W cm-3in ionic liquid. Therefore, this strategy of producing high-density unidirectional VG nanosheets directly bonded on a SiC current collector demonstrated the feasibility of manufacturing high-power compact supercapacitors.
University of Chinese Academy of Sciences , 19 A Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China.
Shuanghao
S
Zheng
Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , P.O. Box 603, Beijing 100190, People's Republic of China.|University of Chinese Academy of Sciences , 19 A Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China.
Zhilin
Z
Li
Zhong-Shuai
0000-0003-1851-4803
ZS
Wu
Yanfeng
Y
Dong
Feng
F
Zhou
University of Chinese Academy of Sciences , 19 A Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China.
Sen
S
Wang
Qiang
0000-0001-5316-6758
Q
Fu
Chenglin
C
Sun
Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , P.O. Box 603, Beijing 100190, People's Republic of China.
Liwei
L
Guo
Xinhe
0000-0001-9404-6429
X
Bao
electrochemical capacitors; energy storage; graphene; high power; micro-supercapacitors; on-chip; vertically aligned