Evaluation of a non-aqueous vanadium redox flow battery using a deep eutectic solvent and graphene-modified carbon electrodes via electrophoretic deposition
Author(s)
Type
Journal Article
Abstract
Common issues aqueous-based vanadium redox flow batteries (VRFBs) face include low cell voltage due to water electrolysis side reactions and highly corrosive and environmentally unfriendly electrolytes (3 to 5 M sulfuric acid). Therefore, this investigation looks into the comparison of a highly conductive ionic liquid with a well-studied deep eutectic solvent (DES) as electrolytes for non-aqueous VRFBs. The latter solvent gives 50% higher efficiency and capacity utilization than the former. These figures of merit increase by 10% when nitrogen-doped graphene (N-G)-modified carbon papers, via a one-step binder-free electrophoretic deposition process, are used as electrodes. X-ray computed tomography confirms the enhancement of electrochemical surface area of the carbon electrodes due to N-G while electrochemical impedance spectra show the effect of its higher conductivity on improving RFB performance. Finally, potential strategies for the scaling-up of DES-based VRFBs using a simple economical model are also briefly discussed. From this study, it is deduced that more investigations on applying DESs as non-aqueous electrolytes to replace the commonly used acetonitrile may be a positive step forward because DESs are not only cheaper but also safer to handle, far less toxic, non-flammable, and less volatile than acetonitrile.
Date Issued
2020-07-13
Date Acceptance
2020-07-06
Citation
Batteries, 2020, 6 (3), pp.1-20
ISSN
2313-0105
Publisher
MDPI
Start Page
1
End Page
20
Journal / Book Title
Batteries
Volume
6
Issue
3
Copyright Statement
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.mdpi.com/2313-0105/6/3/38
Publication Status
Published
Date Publish Online
2020-07-13