Fabrication of highly conductive graphene/graphene oxide based hybrid fiber

Abstract

Graphene Fibers (GFs) are one of the promising candidate for flexible conductors and energy storage devices, which can translate extraordinary properties of individual graphene sheets such as superior electrical conductivity, outstanding mechanical strength, light weight, and flexibility into the macroscopically assembled structures. GFs are fabricated by wet spinning method using liquid crystalline graphene oxides as a precursor to produce well aligned graphene oxide fibers (GOFs) and then restored electrical conductivity by reduction process. However, the reduced GOFs through chemical reduction have much lower electrical conductivity than even graphite due to the remaining oxygen functional groups and defects on the sp2 domains. In this study, highly conductive graphene fibers were fabricated by mixing graphene exfoliated by electrochemical reaction and graphene oxide in liquid crystal state. Electrochemically exfoliated graphene (EG) were used as a major matrix (75 wt% of hybrid dope) to increase the conductivity due to fewer defects and oxygen functional groups than the graphene oxide. On the other hand, the small amount of graphene oxides (25 wt% of hybrid dope) were used as a liquid crystal templates to maintain excellent mechanical strength. The reduced EG/GO hybrid fibers have high electrical conductivity only chemically reduction without expensive high temperature treatment. These hybrid fiber could be one step closer to the commercialization of graphene fibers to practical use.