Rational design strategies for redox flow batteries

Global decarbonization of the energy sector necessitates development of storage technologies to mediate the inherent intermittency of renewable resources. Electrochemical systems are wellpositioned to support this transition with redox flow batteries (RFBs) emerging as a promising grid-scale platfor...

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Main Author: Neyhouse, Bertrand J.
Other Authors: Brushett, Fikile R.
Format: Thesis
Published: Massachusetts Institute of Technology 2023
Online Access:https://hdl.handle.net/1721.1/151298
https://orcid.org/0000-0001-6747-8197
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author Neyhouse, Bertrand J.
author2 Brushett, Fikile R.
author_facet Brushett, Fikile R.
Neyhouse, Bertrand J.
author_sort Neyhouse, Bertrand J.
collection MIT
description Global decarbonization of the energy sector necessitates development of storage technologies to mediate the inherent intermittency of renewable resources. Electrochemical systems are wellpositioned to support this transition with redox flow batteries (RFBs) emerging as a promising grid-scale platform, as their unique architecture offers decoupled energy / power scaling, simplified manufacturing, and long service life. Despite these favorable characteristics, current embodiments remain prohibitively expensive for broad adoption, motivating the development of new electrolyte formulations (e.g., redox molecules, supporting salts, solvents) and reactor materials (e.g., electrodes, flow fields, membranes) to meet performance and cost targets for emerging applications. While many next-generation materials offer performance improvements, they must carefully balance complex tradeoffs between power / energy density, cycling stability, energy efficiency, and capital costs. This multifaceted parameter space frustrates the articulation of unambiguous design criteria, as the relationships between constituent material properties and cell performance metrics are not yet well-understood. In this thesis, I address these knowledge gaps by advancing theoretical and experimental methods that support the rational design of RFBs. First, I develop an in-line electrochemical sensor to measure electrolyte concentrations during RFB operation, providing insight into the dynamics of flow cell cycling. Second, I introduce an analytical zero-dimensional modeling framework for describing RFB cycling behavior, enabling facile simulation of charge / discharge behavior and device performance metrics. I then further simplify this approach by deriving closed-form expressions, facilitating the use of spreadsheet models for cycling simulations. Third, I apply these models to assess design tradeoffs for two-electron materials, demonstrating marked performance limitations. Finally, I leverage the analytical zero-dimensional framework to develop a new technique—compositionally unbalanced symmetric cell cycling—for characterizing crossover rates in redox flow cells. Broadly, the methods developed in this work have the potential to advance foundational understanding in RFB design and operation, leading to more rigorous selection criteria for candidate materials and ultimately supporting more robust, cost-competitive, and durable grid-scale energy storage.
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spelling mit-1721.1/1512982023-08-01T03:02:16Z Rational design strategies for redox flow batteries Neyhouse, Bertrand J. Brushett, Fikile R. Massachusetts Institute of Technology. Department of Chemical Engineering Global decarbonization of the energy sector necessitates development of storage technologies to mediate the inherent intermittency of renewable resources. Electrochemical systems are wellpositioned to support this transition with redox flow batteries (RFBs) emerging as a promising grid-scale platform, as their unique architecture offers decoupled energy / power scaling, simplified manufacturing, and long service life. Despite these favorable characteristics, current embodiments remain prohibitively expensive for broad adoption, motivating the development of new electrolyte formulations (e.g., redox molecules, supporting salts, solvents) and reactor materials (e.g., electrodes, flow fields, membranes) to meet performance and cost targets for emerging applications. While many next-generation materials offer performance improvements, they must carefully balance complex tradeoffs between power / energy density, cycling stability, energy efficiency, and capital costs. This multifaceted parameter space frustrates the articulation of unambiguous design criteria, as the relationships between constituent material properties and cell performance metrics are not yet well-understood. In this thesis, I address these knowledge gaps by advancing theoretical and experimental methods that support the rational design of RFBs. First, I develop an in-line electrochemical sensor to measure electrolyte concentrations during RFB operation, providing insight into the dynamics of flow cell cycling. Second, I introduce an analytical zero-dimensional modeling framework for describing RFB cycling behavior, enabling facile simulation of charge / discharge behavior and device performance metrics. I then further simplify this approach by deriving closed-form expressions, facilitating the use of spreadsheet models for cycling simulations. Third, I apply these models to assess design tradeoffs for two-electron materials, demonstrating marked performance limitations. Finally, I leverage the analytical zero-dimensional framework to develop a new technique—compositionally unbalanced symmetric cell cycling—for characterizing crossover rates in redox flow cells. Broadly, the methods developed in this work have the potential to advance foundational understanding in RFB design and operation, leading to more rigorous selection criteria for candidate materials and ultimately supporting more robust, cost-competitive, and durable grid-scale energy storage. Ph.D. 2023-07-31T19:29:29Z 2023-07-31T19:29:29Z 2023-06 2023-05-19T14:23:07.889Z Thesis https://hdl.handle.net/1721.1/151298 https://orcid.org/0000-0001-6747-8197 Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) Copyright retained by author(s) https://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Neyhouse, Bertrand J.
Rational design strategies for redox flow batteries
title Rational design strategies for redox flow batteries
title_full Rational design strategies for redox flow batteries
title_fullStr Rational design strategies for redox flow batteries
title_full_unstemmed Rational design strategies for redox flow batteries
title_short Rational design strategies for redox flow batteries
title_sort rational design strategies for redox flow batteries
url https://hdl.handle.net/1721.1/151298
https://orcid.org/0000-0001-6747-8197
work_keys_str_mv AT neyhousebertrandj rationaldesignstrategiesforredoxflowbatteries