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Microemulsions: Breakthrough Electrolytes for Redox Flow Batteries

Journal Article · · Frontiers in Chemistry

Aqueous and non-aqueous redox flow batteries (RFBs) have limited energy and current densities, respectively, due to the nature of the electrolytes. New approaches to electrolyte design are needed to improve the performance of RFBs. In this work, we combined a highly conductive aqueous phase and an organic redox-active phase in a microemulsion to formulate a novel RFB electrolyte. As a proof-of-concept, we demonstrate an RFB using this microemulsion electrolyte with maximum current density of 17.5 mA·cm −2 with a 0.19 M posolyte and 0.09 M negolyte at a flow rate of only ∼2.5 ml·min −1 , comparable to early vanadium electrolyte RFBs at similar flow rates on a per molar basis. The novel active negolyte component is an inexpensive oil-soluble vitamin (K 3 ). By combining aqueous and organic phases, the solvent potential window and energy density may be increased without sacrificing current density and new redox couples may be accessed. Microemulsion electrolytes show great promise for improved performance and increased energy densities in aqueous RFBs but the path forward is complex. We end with discussion of areas that need work to achieve the potential of these electrolytes.

Research Organization:
Case Western Reserve Univ., Cleveland, OH (United States); Energy Frontier Research Centers (EFRC) (United States). Breakthrough Electrolytes for Energy Storage (BEES)
Sponsoring Organization:
USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0019409
OSTI ID:
1847431
Alternate ID(s):
OSTI ID: 2471837
Journal Information:
Frontiers in Chemistry, Journal Name: Frontiers in Chemistry Vol. 10; ISSN 2296-2646
Publisher:
Frontiers Media SACopyright Statement
Country of Publication:
Switzerland
Language:
English

References (33)

Redox-Flow Batteries: From Metals to Organic Redox-Active Materials journal November 2016
Interpreting diffusion coefficients of electrochemical probes in oil-in-water microemulsions journal August 1996
Microemulsion structure in the lenticular monophasic areas of brine/SDS/pentanol/dodecane or hexane systems: electrochemical and fluorescent studies journal January 1987
Polarization curve analysis of all-vanadium redox flow batteries journal August 2011
Enhancing solubilization in microemulsions—State of the art and current trends journal January 2005
The Characteristic Curvature of Ionic Surfactants journal May 2008
An unusual electron-transfer behavior of ferrocene in aqueous microemulsion systems journal July 1995
Chemical modification of graphite electrode materials for vanadium redox flow battery application—part II. Acid treatments journal October 1992
Correlations between solvent polarity scales and electron transfer kinetics and an application to micellar media journal June 1992
Electrochemistry in association colloids journal January 1994
Species Uptake and Mass Transport in Membranes for Vanadium Redox Flow Batteries journal May 2017
High Performance Redox Flow Batteries: An Analysis of the Upper Performance Limits of Flow Batteries Using Non-aqueous Solvents journal May 2017
Electrolyte effects on the electrochemical performance of microemulsions journal October 2021
Microstructure and structural transition in coconut oil microemulsion using semidifferential electroanalysis journal August 2007
Alkaline Quinone Flow Battery with Long Lifetime at pH 12 journal September 2018
Unprecedented Capacity and Stability of Ammonium Ferrocyanide Catholyte in pH Neutral Aqueous Redox Flow Batteries journal January 2019
Dramatic performance gains in vanadium redox flow batteries through modified cell architecture journal May 2012
Structure, dynamics and transport properties of microemulsions journal September 1998
The half-wave potential and homogeneous electron-transfer rate constant in sodium dodecyl sulphate micellar solution journal November 1980
Bicontinuous microemulsions as media for electrochemical studies journal March 1990
Microemulsion structure and its effect on electrochemical reactions journal May 1990
Electron Transfer in Microemulsion-Based Electrolytes journal August 2020
Status and Prospects of Organic Redox Flow Batteries toward Sustainable Energy Storage journal August 2019
Advanced Carbon Electrode Materials for Molecular Electrochemistry journal July 2008
Long-Cycling Aqueous Organic Redox Flow Battery (AORFB) toward Sustainable and Safe Energy Storage journal January 2017
Net-Average Curvature Model for Solubilization and Supersolubilization in Surfactant Microemulsions journal December 2002
Amphiphilic Ferrocene Alcohols as Electroactive Probes in Micellar Solutions and Microemulsions journal July 1997
Surfactant widens the electrochemical window of an aqueous electrolyte for better rechargeable aqueous sodium/zinc battery journal January 2017
Spin Diffusion Measurements: Spin Echoes in the Presence of a Time‐Dependent Field Gradient journal January 1965
The structure of micelles and microemulsions journal March 1990
A Study of Ferrocene Diffusion in Toluene/Tween 20/1-Butanol/Water Microemulsions for Redox Flow Battery Applications journal June 2021
Decoupling Conductivity and Solubility in Electrolytes Using Microemulsions journal August 2021
Resolving Losses at the Negative Electrode in All-Vanadium Redox Flow Batteries Using Electrochemical Impedance Spectroscopy journal January 2014

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