Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?

Zhang, Jingjing; Shkrob, Ilya A.; Assary, Rajeev S.; Tung, Siu on; Silcox, Benjamin; Curtiss, Larry A.; Thompson, Levi; Zhang, Lu

doi:10.1021/acs.jpcc.7b08281

Title: Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?

Full Record
Other Related Research

Abstract

We report catholyte materials are used to store positive charge in energized fluids circulating through redox flow batteries (RFBs) for electric grid and vehicle applications. Energy-rich radical cations (RCs) are being considered for use as catholyte materials, but to be practically relevant, these RCs (that are typically unstable, reactive species) need to have long lifetimes in liquid electrolytes under the ambient conditions. Only few families of such energetic RCs possess stabilities that are suitable for their use in RFBs; currently, the derivatives of 1,4- dialkoxybenzene look the most promising. In this study, we examine factors that define the chemical and electrochemical stabilities for RCs in this family. To this end, we engineered rigid bis-annulated molecules that by design avoid the two main degradation pathways for such RCs, viz. their deprotonation and radical addition. The decay of the resulting RCs are due to the single remaining reaction: O-dealkylation. We establish the mechanism for this reaction and examine factors controlling its rate. In particular, we demonstrate that this reaction is initiated by the nucleophile attack of the counter anion on the RC partner. The reaction proceeds through the formation of the aroxyl radicals whose secondary reactions yield the corresponding quinones. The O-dealkylationmore »« less

Authors:

Zhang, Jingjing ^[1];

^[1];

^[2]; Tung, Siu on ^[3]; Silcox, Benjamin ^[3];

^[2]; Thompson, Levi ^[3]; Zhang, Lu ^[1]

Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research and Chemical Sciences and Engineering Division
Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research and Materials Science Division
Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research; Univ. of Michigan, Ann Arbor, MI (United States). Department of Chemical Engineering

Publication Date:: 2017-10-06

Research Org.:: Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1413984

Grant/Contract Number:: AC02-06CH11357

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Physical Chemistry. C

Additional Journal Information:: Journal Volume: 121; Journal Issue: 42; Journal ID: ISSN 1932-7447

Publisher:: American Chemical Society

Country of Publication:: United States

Language:: English

Subject:: 25 ENERGY STORAGE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; chemical kinetics; electron spin resonance; energy storage; radical ions; radical reactions; redox flow battery

Citation Formats


                    Zhang, Jingjing, Shkrob, Ilya A., Assary, Rajeev S., Tung, Siu on, Silcox, Benjamin, Curtiss, Larry A., Thompson, Levi, and Zhang, Lu. Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?.  United States: N. p., 2017. 
Web.  doi:10.1021/acs.jpcc.7b08281.

Copy to clipboard


                    Zhang, Jingjing, Shkrob, Ilya A., Assary, Rajeev S., Tung, Siu on, Silcox, Benjamin, Curtiss, Larry A., Thompson, Levi, & Zhang, Lu. Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?.  United States.  https://doi.org/10.1021/acs.jpcc.7b08281

Copy to clipboard


                    Zhang, Jingjing, Shkrob, Ilya A., Assary, Rajeev S., Tung, Siu on, Silcox, Benjamin, Curtiss, Larry A., Thompson, Levi, and Zhang, Lu. Fri .  
"Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?".  United States.  https://doi.org/10.1021/acs.jpcc.7b08281.  https://www.osti.gov/servlets/purl/1413984.

Copy to clipboard


                    
@article{osti_1413984,

  title        = {Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?},

  author       = {Zhang, Jingjing and Shkrob, Ilya A. and Assary, Rajeev S. and Tung, Siu on and Silcox, Benjamin and Curtiss, Larry A. and Thompson, Levi and Zhang, Lu},

  abstractNote = {We report catholyte materials are used to store positive charge in energized fluids circulating through redox flow batteries (RFBs) for electric grid and vehicle applications. Energy-rich radical cations (RCs) are being considered for use as catholyte materials, but to be practically relevant, these RCs (that are typically unstable, reactive species) need to have long lifetimes in liquid electrolytes under the ambient conditions. Only few families of such energetic RCs possess stabilities that are suitable for their use in RFBs; currently, the derivatives of 1,4- dialkoxybenzene look the most promising. In this study, we examine factors that define the chemical and electrochemical stabilities for RCs in this family. To this end, we engineered rigid bis-annulated molecules that by design avoid the two main degradation pathways for such RCs, viz. their deprotonation and radical addition. The decay of the resulting RCs are due to the single remaining reaction: O-dealkylation. We establish the mechanism for this reaction and examine factors controlling its rate. In particular, we demonstrate that this reaction is initiated by the nucleophile attack of the counter anion on the RC partner. The reaction proceeds through the formation of the aroxyl radicals whose secondary reactions yield the corresponding quinones. The O-dealkylation accelerates considerably when the corresponding quinone has poor solubility in the electrolyte, and the rate depends strongly on the solvent polarity. Finally, our mechanistic insights suggest new ways of improving the RC catholytes through molecular engineering and electrolyte optimization.},

  doi          = {10.1021/acs.jpcc.7b08281},

  journal      = {Journal of Physical Chemistry. C},

  number       = 42,

  volume       = 121,

  place        = {United States},

  year         = {2017},

  month        = {10}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1021/acs.jpcc.7b08281

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 23 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Annulated Dialkoxybenzenes as Catholyte Materials for Non-aqueous Redox Flow Batteries: Achieving High Chemical Stability through Bicyclic Substitution

Journal Article Zhang, Jingjing ; Yang, Zheng ; Shkrob, Ilya A. ; ... - Advanced Energy Materials

1,4-Dimethoxybenzene derivatives are materials of choice for use as catholytes in nonaqueous redox flow batteries, as they exhibit high open-circuit potentials and excellent electrochemical reversibility. However, chemical stability of these materials in their oxidized form needs to be improved. Disubstitution in the arene ring is used to suppress parasitic reactions of their radical cations, but this does not fully prevent ring-addition reactions. By incorporating bicyclic substitutions and ether chains into the dialkoxybenzenes, a novel catholyte molecule, 9,10-bis(2-methoxyethoxy)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanenoanthracene (BODMA), is obtained and exhibits greater solubility and superior chemical stability in the charged state. As a result, a hybrid flow cell containingmore »« less
Cited by 47
https://doi.org/10.1002/aenm.201701272

Full Text Available
Colocalized Raman spectroscopy – scanning electrochemical microscopy investigation of redox flow battery dialkoxybenzene redoxmer degradation pathways

Journal Article Danis, Andrew S. ; Counihan, Michael J. ; Hatfield, Kendrich O. ; ... - Electrochimica Acta

Non-aqueous redox flow batteries offer high voltages for grid-level energy storage technologies. However, decomposition of the redoxmers - redox-active molecules that make up the anolyte and catholyte in the negative and positive cell compartments - is an important challenge to overcome for long-term storage. Here, we present a spectroelectrochemical study of the catholyte candidate 2,3-dimethyl-1,4-dialkoxybenzene (C7) and its decomposition mechanisms in the presence of a model nucleophilic base, pyridine. We utilize colocalized Raman microscopy and scanning electrochemical microscopy (Raman-SECM) to quantify the chemical rates of decom-position and qualitatively identify the reaction intermediates and products. A detailed study on how themore »« less
https://doi.org/10.1016/j.electacta.2023.142123
Molecular Level Understanding of the Factors Affecting the Stability of Dimethoxy Benzene Catholyte Candidates from First-Principles Investigations

Journal Article Assary, Rajeev S. ; Zhang, Lu ; Huang, Jinhua ; ... - Journal of Physical Chemistry. C

First-principles simulations are performed to gain molecular level insights into the factors affecting the stability of seven 1,4-dimethoxybenzene (DMB) derivatives. These molecules are potential catholyte candidates for nonaqueous redox flow battery systems. Computations are performed to predict oxidation potentials in various dielectric mediums, intrinsic-reorganization energies, and structural changes of these representative catholyte molecules during the redox process. In order to understand the stability of the DMB-based radical cations, the thermodynamic feasibility of the following reactions is computed using density functional theory: (a) deprotonation, (b) dimerization, (c) hydrolysis, and (d) demethylation. The computations indicate that radical cations of the 2,3-dimethyl andmore »« less
Cited by 22
https://doi.org/10.1021/acs.jpcc.6b04263
Comparison of Quinone-Based Catholytes for Aqueous Redox Flow Batteries and Demonstration of Long-Term Stability with Tetrasubstituted Quinones

Journal Article Gerken, James B. ; Anson, Colin W. ; Preger, Yuliya ; ... - Advanced Energy Materials

Quinones are appealing targets as organic electrolytes for aqueous redox flow batteries (RFBs), but their utility continues to be constrained by limited stability under operating conditions. The present study evaluates the stability of a series water-soluble quinones, with redox potentials ranging from 605–885 mV vs. NHE, under acidic aqueous conditions (1 M H2SO4). Four of the quinones are examined as cathodic electrolytes in an aqueous RFB, paired with anthraquinone-2,7-disulfonate (AQDS) as the anodic electrolyte. The RFB data complement the solution stability measures and show that the most stable electrolyte is a tetrasubstituted quinone containing four sulfonated thioether substituents. The resultsmore »« less
https://doi.org/10.1002/aenm.202000340
Ambient Temperature Sodium Polysulfide Catholyte for Nonaqueous Redox Flow Batteries

Journal Article Self, Ethan C. ; Tyler, Jameson L. ; Nanda, Jagjit - Journal of the Electrochemical Society

This study reports a sodium polysulfide catholyte for nonaqueous redox flow batteries (RFBs). We demonstrate reversible capacities up to 200 mAh/gS with negligible fade over 250 cycles at room temperature for sodium polysulfide|biphenyl full cells containing Na⁺ß^''-Al₂O₃ solid electrolyte (BASE) membranes. Interestingly, formation of insoluble S and Na₂S₄ phases did not inhibit the catholyte's cycle life which is likely due to the low concentrations used in the lab-scale prototypes. 3-electrode galvanostatic AC impedance measurements demonstrate that voltage losses were dominated by charge transfer at the cathode, and relevant kinetic parameters (i.e., transfer coefficients and exchange current density) were calculated throughmore »« less
https://doi.org/10.1149/1945-7111/ac1e57

Full Text Available

Similar Records