Redox Flow Batteries
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and Chemistry of Materials (http://pubs.acs.org/page/vi/redoxflow-batteries.html). Several important technological aspects of flow batteries are the focus of these 24 papers, including research into new electrolytes (the anolytes and catholytes) with the goal of increasing the volumetric capacity and cyclability of the cell; tailoring the nature of the membrane or porous separator; and addressing critical aspects of operation, such as osmotic pressure and water/ion permeation across the membrane.
he need to develop energy storage technologies for grid distribution has placed added emphasis on flow batteries. Such flow batteries are attractive for storing electricity generated through solar cells and wind turbines. The advantages of flow batteries include the inherent scalability of their capacity (i.e., through simple modulation of the size of the tanks) and long-term storage of charge. Such batteries work on the principles of reversible fuel cells or galvanic cells. In the storage mode, the electrical energy is first converted into chemical energy by transforming a redox couple into a stable reduced or oxidized state (Figure 1). During the discharge cycle
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RELATED READINGS (1) Winsberg, J.; Stolze, C.; Schwenke, A.; Muench, S.; Hager, M. D.; Schubert, U. S. Aqueous 2,2,6,6-TetramethylpiperidineN-oxyl Catholytes for a High-Capacity and High Current Density Oxygen-Insensitive Hybrid-Flow Battery. ACS Energy Lett. 2017, 2, 411−416. DOI: 10.1021/acsenergylett.6b00655. (2) Yan, L. G.; Li, D.; Li, S. Q.; Xu, Z.; Dong, J. H.; Jing, W. H.; Xing, W. H. Balancing Osmotic Pressure of Electrolytes for Nanoporous Membrane Vanadium Redox Flow Battery with a Draw Solute. ACS Appl. Mater. Interfaces 2016, 8, 35289− 35297. DOI: 10.1021/acsami.6b12068. (3) Vijayakumar, M.; Luo, Q. T.; Lloyd, R., Nie, Z. M.; Wei, X. L.; Li, B.; Sprenkle, V.; Londono, J. D.; Unlu, M.; Wang, W. Tuning the Perfluorosulfonic Acid Membrane Morphology for Vanadium Redox-Flow Batteries. ACS Appl. Mater. Interfaces 2016, 8, 34327−34334. DOI: 10.1021/acsami.6b10744. (4) Wu, M.; Bhargav, A.; Cui, Y.; Siegel, A.; Agarwal, M.; Ma, Y.; Fu, Y. Z. Highly Reversible Diphenyl Trisulfide Catholyte for Rechargeable Lithium Batteries. ACS Energy Lett. 2016, 1, 1221−1226. DOI: 10.1021/acsenergylett.6b00533. (5) Winsberg, J.; Stolze, C.; Muench, S.; Liedl, F.; Hager, M. D.; Schubert, U. S. TEMPO/Phenazine Combi-Molecule: A Redox-Active Material for Symmetric Aqueous Redox-Flow Batteries. ACS Energy Lett. 2016, 1, 976−980. DOI: 10.1021/ acsenergylett.6b00413. (6) Burgess, M.; Chenard, E.; Hernandez-Burgos, K.; Nagarjuna, G.; Assary, R. S.; Hui, J. S.; Moore, J. S.; Rodriguez-Lopez, J. Impact of Backbone Tether Length and Structure on the Electrochemical Performance of Viologen Redox Active Polymers. Chem. Mater. 2016, 28, 7362−7374. DOI: 10.1021/acs.chemmater.6b02825. (7) Wei, X. L.; Duan, W. T.; Huang, J. H.; Zhang, L.; Li, B.; Reed, D.; Xu, W.; Sprenkle, V.; Wang, W. A High-Current, Stable Nonaqueous Organic Redox Flow Battery. ACS Energy Lett. 2016, 1, 705−711. DOI: 10.1021/acsenergylett.6b00255. (8) Nikiforidis, G.; Tajima, K.; Byon, H. R. High Energy Efficiency and Stability for Photoassisted Aqueous LithiumIodine Redox Batteries. ACS Energy Lett. 2016, 1, 806−813. DOI: 10.1021/acsenergylett.6b00359. (9) Lee, J.; Choudhury, S.; Weingarth, D.; Kim, D.; Presser, V. High Performance Hybrid Energy Storage with Potassium
Figure 1. Schematic diagram illustrating the principle of redox flow battery. Reprinted from Duan et al., ACS Energy Lett. 2017, 2, 1156−1161. Copyright 2017 American Chemical Society.
or power mode, the stored charge of the redox couple is extracted at the electrodes. The ability of the redox couples to undergo charge-transfer processes quickly and reversibly is the key in achieving a reliable storage technology. To date, both organic and inorganic redox couples have been evaluated to explore their feasibility in redox flow batteries. Whereas the electrochemical reduction and oxidation at electrode surfaces can be demonstrated on a laboratory scale, the practicality of large-scale utilization of the redox couples for charge−discharge cycles remains a challenge. Efforts are needed in the design of new redox couples for maximizing the voltage of the discharge cell, their ability to undergo multiple electron transfer, chemical stability, and long-term recycle capability. Additionally, strategies are needed to develop effective membrane materials to separate the anolyte and catholyte. This Editorial highlights virtual issue content from three sister journals: ACS Energy Letters, ACS Applied Materials & Interfaces, © 2017 American Chemical Society
Published: June 9, 2017 1368
DOI: 10.1021/acsenergylett.7b00361 ACS Energy Lett. 2017, 2, 1368−1369
Editorial
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ACS Energy Letters
Editorial
Ferricyanide Redox Electrolyte. ACS Appl. Mater. Interfaces2016, 8, 23676−23687. DOI: 10.1021/acsami.6b06264. (10) McCulloch, W. D.; Yu, M. Z.; Wu, Y. Y. pH-Tuning a Solar Redox Flow Battery for Integrated Energy Conversion and Storage. ACS Energy Lett. 2016, 1, 578−582. DOI: 10.1021/acsenergylett.6b00296. (11) Gong, K.; Xu, F.; Grunewald, J. B.; Ma, X. Y.; Zhao, Y.; Gu, S.; Yan, Y. S. All-Soluble All-Iron Aqueous Redox-Flow Battery. ACS Energy Lett. 2016, 1, 89−93. DOI: 10.1021/ acsenergylett.6b00049. (12) Zhou, H. P.; Shen, Y.; Xi, J. Y.; Qiu, X. P.; Chen, L. Q. ZrO2-Nanoparticle-Modified Graphite Felt: Bifunctional Effects on Vanadium Flow Batteries. ACS Appl. Mater. Interfaces 2016, 8, 15369−15378. DOI: 10.1021/acsami.6b03761. (13) Winsberg, J.; Hagemann, T.; Muench, S.; Friebe, C.; Haupler, B.; Janoschka, T.; Morgenstern, S.; Hager, M. D.; Schubert, U. S. Poly(boron-dipyrromethene)-A Redox-Active Polymer Class for Polymer Redox-Flow Batteries. Chem. Mater. 2016, 28, 3401−3405. DOI: 10.1021/acs.chemmater.6b00640. (14) Carino, E. V.; Staszak-Jirkovsky, J.; Assary, R. S.; Curtiss, L. A.; Markovic, N. M.; Brushett, F. R. Tuning the Stability of Organic Active Materials for Nonaqueous Redox Flow Batteries via Reversible, Electrochemically Mediated Li+ Coordination Chem. Mater. 2016, 28, 2529−2539. DOI: 10.1021/acs.chemmater.5b04053. (15) Pan, F.; Huang, Q. Z.; Huang, H.; Wang, Q. HighEnergy Density Redox Flow Lithium Battery with Unprecedented Voltage Efficiency. Chem. Mater. 2016, 28, 2052−2057. DOI: 10.1021/acs.chemmater.5b04558. (16) Mubeen, S.; Jun, Y. S.; Lee, J.; McFarland, E. W. Solid Suspension Flow Batteries Using Earth Abundant Materials. ACS Appl. Mater. Interfaces 2016, 8, 1759−1765. DOI: 10.1021/acsami.5b09515. (17) Liu, C. H.; Shamie, J. S.; Shaw, L. L.; Sprenkle, V. L. An Ambient Temperature Molten Sodium-Vanadium Battery with Aqueous Flowing Catholyte. ACS Appl. Mater. Interfaces 2016, 8, 1545−1552. DOI: 10.1021/acsami.5b11503. (18) Frischmann, P. D.; Gerber, L. C. H.; Doris, S. E.; Tsai, E. Y.; Fan, F. Y.; Qu, X. H.; Jain, A.; Persson, K. A.; Chiang, Y. M.; Helms, B. A. Supramolecular Perylene Bisimide-Polysulfide Gel Networks as Nanostructured Redox Mediators in Dissolved Polysulfide Lithium-Sulfur Batteries. Chem. Mater. 2015, 27, 6765−6770. DOI: 10.1021/acs.chemmater.5b02955. (19) Cong, G.; Zhou, Y.; Li, Z.; Lu, Y.-C. A Highly Concentrated Catholyte Enabled by a Low-Melting-Point Ferrocene Derivative. ACS Energy Lett. 2017, 2, 869−875. DOI: 10.1021/acsenergylett.7b00115. (20) Beh, E. S.; De Porcellinis, D. D.; Gracia, R. L.; Xia, K. T.; Gordon, R. G.; Aziz, M. J.A Neutral pH Aqueous Organic− Organometallic Redox Flow Battery with Extremely High Capacity Retention. ACS Energy Lett. 2017, 2, 639−644. DOI: 10.1021/acsenergylett.7b00019. (21) Fan, L.; Jia, C.; Zhu, Y. G.; Wang, Q. Redox Targeting of Prussian Blue: Toward Low-Cost and High Energy Density Redox Flow Battery and Solar Rechargeable Battery. ACS Energy Lett. 2017, 2, 615−621. DOI: 10.1021/acsenergylett.6b00667. (22) Liu, T.; Li, X.; Xu, C.; Zhang, H. Activated Carbon Fiber Paper Based Electrodes with High Electrocatalytic Activity for Vanadium Flow Batteries with Improved Power Density. ACS Appl. Mater. Interfaces 2017, 9, 4626−4633. DOI: 10.1021/acsami.6b14478.
(23) Yu, L.; Xi, J. Durable and Efficient PTFE Sandwiched SPEEK Membrane for Vanadium Flow Batteries. ACS Appl. Mater. Interfaces 2016, 8, 23425−23430. DOI: 10.1021/ acsami.6b07782. (24) Duan, W.; Huang, J.; Kowalski, J. A.; Shkrob, I. A.; Vijayakumar, M.; Walter, E.; Pan, B.; Yang, Z.; Milshtein, J. D.; Li, B. “Wine-Dark Sea” in an Organic Flow Battery: Storing Negative Charge in 2,1,3-Benzothiadiazole Radicals Leads to Improved Cyclability. ACS Energy Lett. 2017, 2, 1156−1161. DOI: 10.1021/acsenergylett.7b00261.
Prashant V. Kamat, Editor-in-Chief, ACS Energy Letters University of Notre Dame
Kirk S. Schanze, Editor-in-Chief, ACS Applied Materials & Interfaces University of Texas at San Antonio
Jillian M. Buriak, Editor-in-Chief, Chemistry of Materials
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University of Alberta
AUTHOR INFORMATION
ORCID
Prashant V. Kamat: 0000-0002-2465-6819 Kirk S. Schanze: 0000-0003-3342-4080 Jillian M. Buriak: 0000-0002-9567-4328 Notes
Views expressed in this editorial are those of the authors and not necessarily the views of the ACS.
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DOI: 10.1021/acsenergylett.7b00361 ACS Energy Lett. 2017, 2, 1368−1369
