Fundamental properties of TEMPO-based catholytes for aqueous redox flow batteries: effects of substituent groups and electrolytes on electrochemical properties, solubilities and battery performance

Water-soluble 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivatives have been frequently utilized as catholytes for aqueous redox flow batteries to achieve cost-effective renewable energy storage. However, fundamental knowledge of TEMPO derivatives is still largely underdeveloped. Herein, a compr...

Full description

Saved in:
Bibliographic Details
Published in:RSC advances 2020-06, Vol.1 (37), p.21839-21844
Main Authors: Zhou, Wenbo, Liu, Wenjie, Qin, Meng, Chen, Zhidong, Xu, Juan, Cao, Jianyu, Li, Jun
Format: Article
Language:English
Subjects:
Aqueous electrolytes
Catholytes
Chemistry
Derivatives
Diffusion coefficient
Diffusion rate
Electrochemical analysis
Electrolytes
Electron transfer
Energy storage
Functional groups
Performance evaluation
Properties (attributes)
Rechargeable batteries
Solubility
Storage batteries
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Water-soluble 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivatives have been frequently utilized as catholytes for aqueous redox flow batteries to achieve cost-effective renewable energy storage. However, fundamental knowledge of TEMPO derivatives is still largely underdeveloped. Herein, a comprehensive study on the properties of TEMPO derivatives has been conducted in aqueous electrolytes. The results confirm that the redox potential, diffusion coefficient, electron transfer rate constant and solubility are clearly influenced by functional groups of TEMPO derivatives and supporting electrolytes. The charge-discharge cycling performance is evaluated using a symmetric redox flow battery configuration. The capacity decay for TEMPO-based catholytes is mainly derived from the crossover of the oxidized state. The presented study not only advances an in-depth understanding of TEMPO-based RFB applications, but also highlights the challenge of crossover of redox-active TEMPO derivative molecules applied in aqueous RFBs. The effects of substituent groups of TEMPO-based catholytes and supporting electrolytes on electrochemical properties, solubility and battery performance were examined systematically for aqueous redox flow batteries.
ISSN:2046-2069
2046-2069
DOI:10.1039/d0ra03424j