Improving electrochemical properties of carbon nanotubes/reduced graphene oxide composite fibers by chemical modification
- Resource Type
- Original Paper
- Authors
- Wang, Songyan; Cao, Kaiwen; Xu, Lianghua; Tong, Yuanjian
- Source
- Applied Physics A: Materials Science & Processing. 129(1)
- Subject
- Graphene oxide
Polyacrylonitrile
Carbon nanotube
Supercapacitor
Chemical modification
Electrochemical properties
- Language
- English
- ISSN
- 0947-8396
1432-0630
To promote application of graphene fiber as electrode for supercapacitors, carbon nanotubes (CNTs)/reduced graphene oxide (RGO) composite fibers were fabricated with GO/polyacrylonitrile (PAN) fibers using chemical vapor deposition method, and then treated with mixed acid to modify the hydrophilicity of the fiber. Transformation of excellent nano-scale properties of graphene and CNTs into macroscopic material properties was realized. The GO/PAN fiber was prepared by wet spinning and thermal stabilized in advance before in situ growth of CNTs to the fiber. Structures and electrochemical properties of the CNTs/RGO composite fiber were investigated. Interaction between GO and PAN during stabilization resulted in less mass loss of the fiber. The CNTs/RGO composite fibers exhibited a specific surface area of 87.873 m2 g−1 with large quantity of entwined CNTs about 39–130 nm in diameter and centimeters in length. Increase of 37.43% oxygen-containing functional groups greatly improved the hydrophilicity of the fiber after chemical modification. The specific capacitance increased from 34 to 141 F g−1 at 0.1 A g−1 for the CNTs/RGO composite fibers due to improved ionic accessibility and pseudo-capacitance provided by oxygen-containing functional groups. The chemical modified CNTs/RGO fiber is suitable for electrode material of supercapacitors due to its excellent cycle stability with specific capacitance retention of 96% after 2500 cycles of the charge/discharge process and low ESR and Rct. A method for the synthesis of CNTs/RGO composite fibers with good three-dimensional structures and an idea of modifying ionic accessibility to improve the electrochemical performance of the fibers was presented.