State of Charge and Capacity Tracking in Vanadium Redox Flow Battery Systems

Kalvin Schofield and Petr Musilek
Additional contact information
Kalvin Schofield: Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
Petr Musilek: Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada

Clean Technol., 2022, vol. 4, issue 3, 1-12

Abstract: The vanadium redox flow battery electrolyte is prone to several capacity loss mechanisms, which must be mitigated to preserve electrolyte health and battery performance. This study investigates a simple and effective technique for the recovery of capacity loss arising from symmetrical mechanisms via automatic electrolyte rebalancing. However, chemical or electrochemical techniques must be used to mitigate capacity loss from asymmetrical mechanisms (e.g., air oxidation of V 2 + ), which requires knowledge of the oxidation states present in the electrolytes. As such, this study assesses the suitability of SOC tracking via electrolyte absorption for independent monitoring of the anolyte and catholyte within an existing VRFB system. Testing is performed over cycling of a 40 cell, 2.5 kW with 40 L of electrolyte. Optical monitoring is performed using a custom-made flow cell with optical paths (interior cavity thicknesses) ranging from 1/4 ″ to 1/16 ″ . Light transmitted through the cell by a 550 lumen white light source is monitored by a simple photodiode. The electrolyte rebalancing mechanism displayed success in recovering symmetrical capacity losses, while optical monitoring was unsuccessful due to the high absorbance of the electrolyte. Potential improvements to the monitoring system are presented to mitigate this issue.

Keywords: VRFB; SOC; capacity; redox flow; optoelectronics; vanadium; mitigation (search for similar items in EconPapers)
JEL-codes: Q2 Q3 Q4 Q5 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.mdpi.com/2571-8797/4/3/37/pdf (application/pdf)
https://www.mdpi.com/2571-8797/4/3/37/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jcltec:v:4:y:2022:i:3:p:37-618:d:850359

Access Statistics for this article

Clean Technol. is currently edited by Ms. Shary Song

More articles in Clean Technol. from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().