Issue 3, 2024

Improved coulombic efficiency of single-flow, multiphase flow batteries via the use of strong-binding complexing agents

Abstract

To support the energy transition, an inexpensive grid-scale energy storage device is needed to counteract the intermittency of renewable energy sources. Redox flow batteries (RFBs) offer the potential provide such storage, however, high capital costs have hampered market penetration. To reduce costs, single-flow configurations have been explored to eliminate expensive battery components and minimize balance of plant systems. Here, we report on a membraneless single-flow zinc–bromine battery leveraging a unique multiphase electrolyte. The use of such electrolyte emulsions, containing a bromine-poor aqueous phase and bromine-rich polybromide phase, have allowed for effective reactant separation in single-flow architectures, although at the cost of low cycling coulombic efficiency (CE). In this study, we show that significant improvements in CEs are possible when using strong-binding bromine complexing agents (BCAs) to form the polybromide phase. We compare battery performance when using widespread but relatively weak-binding BCA N-ethyl-N-methylpyrrolidinium bromide (MEP) or novel, stronger-binding 1-butyl-3-methylpyridinium bromide (3-MBPy). We characterize for the first time the ex situ viscosity, ionic conductivity and aqueous phase bromine concentration for such emulsive electrolytes, towards building a library of emulsive electrolyte properties. We show that the use of 3-MBPy significantly reduced zinc corrosion during cycling due to a reduced aqueous phase bromine concentration, enabling an up to 23% increase in CE when cycling at 30 mA cm−2.

Graphical abstract: Improved coulombic efficiency of single-flow, multiphase flow batteries via the use of strong-binding complexing agents

Supplementary files

Article information

Article type
Paper
Submitted
22 iyn 2023
Accepted
08 yan 2024
First published
09 yan 2024
This article is Open Access
Creative Commons BY-NC license

Energy Adv., 2024,3, 592-600

Improved coulombic efficiency of single-flow, multiphase flow batteries via the use of strong-binding complexing agents

P. Rewatkar, M. Asarthen S, R. Glouckhovski, R. Elazari and M. E. Suss, Energy Adv., 2024, 3, 592 DOI: 10.1039/D3YA00293D

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements