Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6612529 | Electrochimica Acta | 2015 | 7 Pages |
Abstract
Graphene/acetylene black sandwich film was fabricated by a simple vacuum filtration procedure using a stable complex suspension of graphene oxide (GO) and acetylene black followed by a hydroiodic acid (HI) immersion process to fully reduce the GO to graphene sheets. The self-restacking of individual graphene sheets were greatly alleviated and electric conductivity was obviously improved using the acetylene black nanoparticles as both effective spacers to expand the inter-layer interval of the individual graphene sheets during the film assembly course and highly conducting bridges to facilitate the electron/ion transfer between the upper and lower graphene sheets. The flexible graphene/acetylene black film was utilized as supercapacitor electrode without additional conductive additives, binders and current collectors, which achieved an obviously higher specific capacitance (ca. 136.6Â FÂ gâ1 at 0.5Â AÂ gâ1) and much better specific capacitance retention at high current densities than that of the pure graphene film electrode, indicating that such a novel sandwich film structure allows for a higher charge storage capability. More importantly, the assembled symmetric supercapacitor device displayed a satisfactory specific capacitance of 59.2Â FÂ gâ1 at 0.1Â AÂ gâ1, 47.6Â FÂ gâ1 at 0.5Â AÂ gâ1 and 42.8Â FÂ gâ1 at 1Â AÂ gâ1, and only negligible 4.05% capacitance degradation have been found after 1000 continuous charge-discharge cycles at 0.5Â AÂ gâ1, revealing outstanding rate capability, excellent electrochemical reversibility and long-term cyclability. These results proved that such a flexible and highly conductive graphene/acetylene black film can be promising electroactive materials in the development of advanced electrochemical energy storage devices.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Juan Xu, Xicheng Wei, Jianyu Cao, Yuanzhu Dong, Guoxin Wang, Yufei Xue, Wenchang Wang, Zhidong Chen,