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Graphene-enhanced electrodes for scalable supercapacitors.
- Source :
-
Electrochimica Acta . Dec2017, Vol. 257, p372-379. 8p. - Publication Year :
- 2017
-
Abstract
- A scale-up process of high-rate-capability supercapacitors based on electrochemically exfoliated graphene (EEG) and hybrid activated carbon (AC)/EEG are studied in this work. A comparison of the rate capabilities of large-scale EEG and AC/EEG-based pouch cell and commercial high-power supercapacitors are also presented in this paper. The oxygen content of the EEG used in this work is 9.6 at%, with a C/O ratio of 9.36, and the electrical conductivity is 2.68 × 10 4 Sm −1 . The specific capacitance (59 Fg −1 ) of the EEG-based supercapacitors remained above 80% of the maximum value as the scan rate was increased from 5 mVs −1 to 1 Vs −1 . Furthermore, our study reveals how the rate capability of activated carbon (AC) based supercapacitors can be improved by adding EEG into the electrodes to form a hybrid AC/EEG supercapacitor. Both the EEG-based and AC/EEG supercapacitors were scaled-up to pouch cells with capacitances of tens of farads. The electrochemical response was unchanged when scaling up from a coin cell to a pouch cell, although the specific capacitance fell slightly. The cycle performance of the AC/EEG pouch cell showed good long-term stability, with better than 95% capacitance retention after 10,000 cycles. Both the EEG and AC/EEG (with 1:1 mass ratio) pouch cells had rate capabilities that compared favourably with the commercial high-power supercapacitors. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00134686
- Volume :
- 257
- Database :
- Academic Search Index
- Journal :
- Electrochimica Acta
- Publication Type :
- Academic Journal
- Accession number :
- 126009968
- Full Text :
- https://doi.org/10.1016/j.electacta.2017.10.056