Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Emerging chemistries and molecular designs for flow batteries

Abstract

Redox flow batteries are a critical technology for large-scale energy storage, offering the promising characteristics of high scalability, design flexibility and decoupled energy and power. In recent years, they have attracted extensive research interest, with significant advances in relevant materials chemistry, performance metrics and characterization. The emerging concepts of hybrid battery design, redox-targeting strategy, photoelectrode integration and organic redox-active materials present new chemistries for cost-effective and sustainable energy storage systems. This Review summarizes the recent development of next-generation redox flow batteries, providing a critical overview of the emerging redox chemistries of active materials from inorganics to organics. We discuss electrochemical characterizations and critical performance assessment considering the intrinsic properties of the active materials and the mechanisms that lead to degradation of energy storage capacity. In particular, we highlight the importance of advanced spectroscopic analysis and computational studies in enabling understanding of relevant mechanisms. We also outline the technical requirements for rational design of innovative materials and electrolytes to stimulate more exciting research and present the prospect of this field from aspects of both fundamental science and practical applications.

This is a preview of subscription content, access via your institution

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Fig. 1: Development of important flow battery types.
Fig. 2: Development of representative materials chemistry for redox flow batteries.
Fig. 3: Evaluation of electrochemical properties and performance assessment.
Fig. 4: Capacity loss mechanisms in redox flow batteries.
Fig. 5: Spectroscopic characterizations for understanding the materials chemistry.
Fig. 6: Computational study to understand and guide rational designs of redox-active molecules.
Fig. 7: Future prospects for the development of next-generation RFBs.

References

  1. Van Noorden, R. The rechargeable revolution: a better battery. Nature 507, 26–28 (2014).

    PubMed  Article  CAS  Google Scholar 

  2. Dunn, B., Kamath, H. & Tarascon, J.-M. Electrical energy storage for the grid: a battery of choices. Science 334, 928–935 (2011).

    CAS  PubMed  Article  Google Scholar 

  3. Choi, J. W. & Aurbach, D. Promise and reality of post-lithium-ion batteries with high energy densities. Nat. Rev. Mater. 1, 16013 (2016).

    CAS  Article  Google Scholar 

  4. Yang, Z. et al. Electrochemical energy storage for green grid. Chem. Rev. 111, 3577–3613 (2011).

    CAS  PubMed  Article  Google Scholar 

  5. Li, B. & Liu, J. Progress and directions in low-cost redox-flow batteries for large-scale energy storage. Natl Sci. Rev. 4, 91–105 (2017).

    CAS  Article  Google Scholar 

  6. Dowling, J. A. et al. Role of long-duration energy storage in variable renewable electricity systems. Joule 4, 1907–1928 (2020).

    Article  Google Scholar 

  7. Sepulveda, N. A., Jenkins, J. D., Edington, A., Mallapragada, D. S. & Lester, R. K. The design space for long-duration energy storage in decarbonized power systems. Nat. Energy 6, 506–516 (2021).

    Article  Google Scholar 

  8. Hunter, C. A. et al. Techno-economic analysis of long-duration energy storage and flexible power generation technologies to support high-variable renewable energy grids. Joule 5, 2077–2101 (2021).

    Article  Google Scholar 

  9. Soloveichik, G. L. Flow batteries: current status and trends. Chem. Rev. 115, 11533–11558 (2015).

    CAS  PubMed  Article  Google Scholar 

  10. Park, M., Ryu, J., Wang, W. & Cho, J. Material design and engineering of next-generation flow-battery technologies. Nat. Rev. Mater. 2, 16080 (2017).

    CAS  Article  Google Scholar 

  11. Wang, Y., He, P. & Zhou, H. Li-redox flow batteries based on hybrid electrolytes: at the cross road between Li-ion and redox flow batteries. Adv. Energy Mater. 2, 770–779 (2012).

    CAS  Article  Google Scholar 

  12. Zhao, Y. et al. A chemistry and material perspective on lithium redox flow batteries towards high-density electrical energy storage. Chem. Soc. Rev. 44, 7968–7996 (2015).

    CAS  PubMed  Article  Google Scholar 

  13. Gong, K., Fang, Q., Gu, S., Li, S. F. Y. & Yan, Y. Nonaqueous redox-flow batteries: organic solvents, supporting electrolytes, and redox pairs. Energy Environ. Sci. 8, 3515–3530 (2015).

    Article  Google Scholar 

  14. Ding, Y., Zhang, C., Zhang, L., Zhou, Y. & Yu, G. Molecular engineering of organic electroactive materials for redox flow batteries. Chem. Soc. Rev. 47, 69–103 (2018). A systematic overview of the development of redox-active organic materials for RFBs.

    CAS  PubMed  Article  Google Scholar 

  15. Xiong, P., Zhang, L., Chen, Y., Peng, S. & Yu, G. A chemistry and microstructure perspective on ion-conducting membranes for redox flow batteries. Angew. Chem. Int. Ed. 60, 24770–24798 (2021).

    CAS  Article  Google Scholar 

  16. Li, X., Zhang, H., Mai, Z., Zhang, H. & Vankelecom, I. Ion exchange membranes for vanadium redox flow battery (VRB) applications. Energy Environ. Sci. 4, 1147–1160 (2011).

    CAS  Article  Google Scholar 

  17. Yuan, Z., Zhang, H. & Li, X. Ion conducting membranes for aqueous flow battery systems. Chem. Commun. 54, 7570–7588 (2018).

    CAS  Article  Google Scholar 

  18. Chen, D. et al. Polybenzimidazole membrane with dual proton transport channels for vanadium flow battery applications. J. Membr. Sci. 586, 202–210 (2019).

    CAS  Article  Google Scholar 

  19. Chen, D., Chen, X., Ding, L. & Li, X. Advanced acid-base blend ion exchange membranes with high performance for vanadium flow battery application. J. Membr. Sci. 553, 25–31 (2018).

    CAS  Article  Google Scholar 

  20. Peng, S. et al. Polybenzimidazole membranes with nanophase-separated structure induced by non-ionic hydrophilic side chains for vanadium flow batteries. J. Mater. Chem. A 6, 3895–3905 (2018).

    CAS  Article  Google Scholar 

  21. Shi, M. et al. Membranes with well-defined selective layer regulated by controlled solvent diffusion for high power density flow battery. Adv. Energy Mater. 10, 2001382 (2020).

    CAS  Article  Google Scholar 

  22. Dai, Q. et al. Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery. Nat. Commun. 11, 13 (2020).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  23. Zhang, L. et al. Enabling graphene-oxide-based membranes for large-scale energy storage by controlling hydrophilic microstructures. Chem 4, 1035–1046 (2018).

    CAS  Article  Google Scholar 

  24. Baran, M. J. et al. Design rules for membranes from polymers of intrinsic microporosity for crossover-free aqueous electrochemical devices. Joule 3, 2968–2985 (2019).

    CAS  Article  Google Scholar 

  25. Tan, R. et al. Hydrophilic microporous membranes for selective ion separation and flow-battery energy storage. Nat. Mater. 19, 195–202 (2020).

    CAS  PubMed  Article  Google Scholar 

  26. Zuo, P. et al. Sulfonated microporous polymer membranes with fast and selective ion transport for electrochemical energy conversion and storage. Angew. Chem. Int. Ed. 132, 9651–9660 (2020).

    Article  Google Scholar 

  27. Peng, S. et al. Gradient-distributed metal–organic framework–based porous membranes for nonaqueous redox flow batteries. Adv. Energy Mater. 8, 1802533 (2018).

    Article  CAS  Google Scholar 

  28. Yuan, J. et al. Membranes in non-aqueous redox flow battery: a review. J. Power Sources 500, 229983 (2021).

    CAS  Article  Google Scholar 

  29. Ke, X. et al. Rechargeable redox flow batteries: flow fields, stacks and design considerations. Chem. Soc. Rev. 47, 8721–8743 (2018).

    CAS  PubMed  Article  Google Scholar 

  30. Jiang, H. et al. A high power density and long cycle life vanadium redox flow battery. Energy Stor. Mater. 24, 529–540 (2020).

    Article  Google Scholar 

  31. Mukhopadhyay, A. et al. Mass transfer and reaction kinetic enhanced electrode for high-performance aqueous flow batteries. Adv. Funct. Mater. 29, 1903192 (2019).

    CAS  Article  Google Scholar 

  32. Zhang, C. et al. Progress and prospects of next-generation redox flow batteries. Energy Stor. Mater. 15, 324–350 (2018).

    Article  Google Scholar 

  33. Ding, Y., Zhang, C., Zhang, L., Zhou, Y. & Yu, G. Pathways to widespread applications: development of redox flow batteries based on new chemistries. Chem 5, 1964–1987 (2019).

    CAS  Article  Google Scholar 

  34. Li, W. & Jin, S. Design principles and developments of integrated solar flow batteries. Acc. Chem. Res. 53, 2611–2621 (2020).

    CAS  PubMed  Article  Google Scholar 

  35. Yan, R. & Wang, Q. Redox-targeting-based flow batteries for large-scale energy storage. Adv. Mater. 30, 1802406 (2018).

    Article  CAS  Google Scholar 

  36. Yuan, Z. et al. Advanced materials for zinc-based flow battery: development and challenge. Adv. Mater. 31, 1902025 (2019).

    CAS  Article  Google Scholar 

  37. Yuan, Z. et al. Negatively charged nanoporous membrane for a dendrite-free alkaline zinc-based flow battery with long cycle life. Nat. Commun. 9, 3731 (2018).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  38. Duduta, M. et al. Semi-solid lithium rechargeable flow battery. Adv. Energy Mater. 1, 511–516 (2011).

    CAS  Article  Google Scholar 

  39. Chen, H. et al. Sulphur-impregnated flow cathode to enable high-energy-density lithium flow batteries. Nat. Commun. 6, 5877 (2015).

    CAS  PubMed  Article  Google Scholar 

  40. Ventosa, E., Amedu, O. & Schuhmann, W. Aqueous mixed-cation semi-solid hybrid-flow batteries. ACS Appl. Energy Mater. 1, 5158–5162 (2018).

    CAS  Article  Google Scholar 

  41. Jia, C. et al. High–energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane. Sci. Adv. 1, e1500886 (2015).

    PubMed  PubMed Central  Article  Google Scholar 

  42. Zhu, Y. G. et al. Unleashing the power and energy of LiFePO4-based redox flow lithium battery with a bifunctional redox mediator. J. Am. Chem. Soc. 139, 6286–6289 (2017).

    CAS  PubMed  Article  Google Scholar 

  43. Chen, Y. et al. A stable and high-capacity redox targeting-based electrolyte for aqueous flow batteries. Joule 3, 2255–2267 (2019).

    CAS  Article  Google Scholar 

  44. Zhou, M. et al. Nernstian-potential-driven redox-targeting reactions of battery materials. Chem 3, 1036–1049 (2017).

    CAS  Article  Google Scholar 

  45. Zhou, Y. et al. Efficient solar energy harvesting and storage through a robust photocatalyst driving reversible redox reactions. Adv. Mater. 30, 1802294 (2018).

    Article  CAS  Google Scholar 

  46. Li, W. et al. High-performance solar flow battery powered by a perovskite/silicon tandem solar cell. Nat. Mater. 19, 1326–1331 (2020).

    CAS  PubMed  Article  Google Scholar 

  47. Luo, J., Hu, B., Hu, M., Zhao, Y. & Liu, T. L. Status and prospects of organic redox flow batteries toward sustainable energy storage. ACS Energy Lett. 4, 2220–2240 (2019).

    CAS  Article  Google Scholar 

  48. Li, Z. & Lu, Y. C. Material design of aqueous redox flow batteries: fundamental challenges and mitigation strategies. Adv. Mater. 32, 2002132 (2020).

    CAS  Article  Google Scholar 

  49. Reale, E. R., Shrivastava, A. & Smith, K. C. Effect of conductive additives on the transport properties of porous flow-through electrodes with insulative particles and their optimization for Faradaic deionization. Water Res. 165, 114995 (2019).

    CAS  PubMed  Article  Google Scholar 

  50. Murray, A. T., Voskian, S., Schreier, M., Hatton, T. A. & Surendranath, Y. Electrosynthesis of hydrogen peroxide by phase-transfer catalysis. Joule 3, 2942–2954 (2019).

    CAS  Article  Google Scholar 

  51. Wang, F. et al. Modular electrochemical synthesis using a redox reservoir paired with independent half-reactions. Joule 5, 149–165 (2021).

    CAS  Article  Google Scholar 

  52. Ren, S. et al. Molecular electrocatalysts can mediate fast, selective CO2 reduction in a flow cell. Science 365, 367–369 (2019).

    CAS  PubMed  Article  Google Scholar 

  53. Luo, J., Hu, B., Wu, W., Hu, M. & Liu, T. L. Nickel-catalyzed electrochemical C(sp3)–C(sp2) cross-coupling reactions of benzyl trifluoroborate and organic halides. Angew. Chem. Int. Ed. 60, 6107–6116 (2021).

    CAS  Article  Google Scholar 

  54. Mo, Y. et al. Microfluidic electrochemistry for single-electron transfer redox-neutral reactions. Science 368, 1352–1357 (2020).

    CAS  PubMed  Article  Google Scholar 

  55. Novaes, L. F. T. et al. Electrocatalysis as an enabling technology for organic synthesis. Chem. Soc. Rev. 50, 7941–8002 (2021).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  56. Yan, M., Kawamata, Y. & Baran, P. S. Synthetic organic electrochemical methods since 2000: on the verge of a renaissance. Chem. Rev. 117, 13230–13319 (2017).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  57. Winsberg, J., Hagemann, T., Janoschka, T., Hager, M. D. & Schubert, U. S. Redox-flow batteries: from metals to organic redox-active materials. Angew. Chem. Int. Ed. 56, 686–711 (2017).

    CAS  Article  Google Scholar 

  58. Hnedkovsky, L., Wood, R. H. & Balashov, V. N. Electrical conductances of aqueous Na2SO4, H2SO4, and their mixtures: limiting equivalent ion conductances, dissociation constants, and speciation to 673 K and 28 MPa. J. Phys. Chem. B 109, 9034–9046 (2005).

    CAS  PubMed  Article  Google Scholar 

  59. Su, L. et al. An investigation of the ionic conductivity and species crossover of lithiated nafion 117 in nonaqueous electrolytes. J. Electrochem. Soc. 163, A5253 (2015).

    Article  CAS  Google Scholar 

  60. Aaron, D. et al. Dramatic performance gains in vanadium redox flow batteries through modified cell architecture. J. Power Sources 206, 450–453 (2012).

    CAS  Article  Google Scholar 

  61. Suo, L. et al. “Water-in-salt” electrolyte enables high-voltage aqueous lithium-ion chemistries. Science 350, 938–943 (2015).

    CAS  PubMed  Article  Google Scholar 

  62. Wang, W. et al. Recent progress in redox flow battery research and development. Adv. Funct. Mater. 23, 970–986 (2013).

    CAS  Article  Google Scholar 

  63. Zhang, L. & Yu, G. Hybrid electrolyte engineering enables safe and wide-temperature redox flow batteries. Angew. Chem. Int. Ed. 60, 15028–15035 (2021).

    CAS  Article  Google Scholar 

  64. Shin, S.-H., Yun, S.-H. & Moon, S.-H. A review of current developments in non-aqueous redox flow batteries: characterization of their membranes for design perspective. RSC Adv. 3, 9095–9116 (2013).

    CAS  Article  Google Scholar 

  65. Leung, P. et al. Recent developments in organic redox flow batteries: a critical review. J. Power Sources 360, 243–283 (2017).

    CAS  Article  Google Scholar 

  66. Xu, K. Nonaqueous liquid electrolytes for lithium-based rechargeable batteries. Chem. Rev. 104, 4303–4418 (2004).

    CAS  PubMed  Article  Google Scholar 

  67. Wei, X. et al. Radical compatibility with nonaqueous electrolytes and its impact on an all-organic redox flow battery. Angew. Chem. Int. Ed. 54, 8684–8687 (2015).

    CAS  Article  Google Scholar 

  68. Darling, R. M., Gallagher, K. G., Kowalski, J. A., Ha, S. & Brushett, F. R. Pathways to low-cost electrochemical energy storage: a comparison of aqueous and nonaqueous flow batteries. Energy Environ. Sci. 7, 3459–3477 (2014).

    CAS  Article  Google Scholar 

  69. Zhao, Y. et al. A reversible Br2/Br redox couple in the aqueous phase as a high-performance catholyte for alkali-ion batteries. Energy Environ. Sci. 7, 1990–1995 (2014).

    CAS  Article  Google Scholar 

  70. Zhao, Y., Wang, L. & Byon, H. R. High-performance rechargeable lithium-iodine batteries using triiodide/iodide redox couples in an aqueous cathode. Nat. Commun. 4, 1896 (2013).

    PubMed  Article  CAS  Google Scholar 

  71. Chen, H. & Lu, Y.-C. A high-energy-density multiple redox semi-solid-liquid flow battery. Adv. Energy Mater. 6, 1502183 (2016).

    Article  CAS  Google Scholar 

  72. Xie, C., Duan, Y., Xu, W., Zhang, H. & Li, X. A low-cost neutral zinc–iron flow battery with high energy density for stationary energy storage. Angew. Chem. Int. Ed. 56, 14953–14957 (2017).

    CAS  Article  Google Scholar 

  73. Xie, C. et al. A highly reversible neutral zinc/manganese battery for stationary energy storage. Energy Environ. Sci. 13, 135–143 (2020).

    CAS  Article  Google Scholar 

  74. Wei, X. et al. Materials and systems for organic redox flow batteries: status and challenges. ACS Energy Lett. 2, 2187–2204 (2017).

    CAS  Article  Google Scholar 

  75. Ding, Y. & Yu, G. A bio-inspired, heavy-metal-free, dual-electrolyte liquid battery towards sustainable energy storage. Angew. Chem. Int. Ed. 55, 4772–4776 (2016).

    CAS  Article  Google Scholar 

  76. Lin, K. et al. Alkaline quinone flow battery. Science 349, 1529–1532 (2015).

    CAS  PubMed  Article  Google Scholar 

  77. Huskinson, B. et al. A metal-free organic–inorganic aqueous flow battery. Nature 505, 195–198 (2014).

    CAS  PubMed  Article  Google Scholar 

  78. Wei, X. et al. TEMPO-based catholyte for high-energy density nonaqueous redox flow batteries. Adv. Mater. 26, 7649–7653 (2014).

    CAS  PubMed  Article  Google Scholar 

  79. Liu, T., Wei, X., Nie, Z., Sprenkle, V. & Wang, W. A total organic aqueous redox flow battery employing a low cost and sustainable methyl viologen anolyte and 4-HO-TEMPO catholyte. Adv. Energy Mater. 6, 1501449 (2016). One of the first demonstrations of an aqueous all-organic RFB.

    Article  CAS  Google Scholar 

  80. Janoschka, T., Martin, N., Hager, M. D. & Schubert, U. S. An aqueous redox-flow battery with high capacity and power: the TEMPTMA/MV system. Angew. Chem. Int. Ed. 55, 14427–14430 (2016).

    CAS  Article  Google Scholar 

  81. Hu, B., DeBruler, C., Rhodes, Z. & Liu, T. L. Long-cycling aqueous organic redox flow battery (AORFB) toward sustainable and safe energy storage. J. Am. Chem. Soc. 139, 1207–1214 (2017).

    CAS  PubMed  Article  Google Scholar 

  82. DeBruler, C. et al. Designer two-electron storage viologen anolyte materials for neutral aqueous organic redox flow batteries. Chem 3, 961–978 (2017).

    CAS  Article  Google Scholar 

  83. Luo, J., Hu, B., Debruler, C. & Liu, T. L. A π-conjugation extended viologen as a two-electron storage anolyte for total organic aqueous redox flow batteries. Angew. Chem. Int. Ed. 57, 231–235 (2018).

    CAS  Article  Google Scholar 

  84. Milshtein, J. D. et al. High current density, long duration cycling of soluble organic active species for non-aqueous redox flow batteries. Energy Environ. Sci. 9, 3531–3543 (2016).

    CAS  Article  Google Scholar 

  85. Kowalski, J. A. et al. A stable two-electron-donating phenothiazine for application in nonaqueous redox flow batteries. J. Mater. Chem. A 5, 24371–24379 (2017).

    CAS  Article  Google Scholar 

  86. Hollas, A. et al. A biomimetic high-capacity phenazine-based anolyte for aqueous organic redox flow batteries. Nat. Energy 3, 508–514 (2018). An example of molecular engineering with screening of functional groups en route to a promising phenazine-based anolyte for aqueous RFBs.

    CAS  Article  Google Scholar 

  87. Zhang, C. et al. Phenothiazine-based organic catholyte for high-capacity and long-life aqueous redox flow batteries. Adv. Mater. 31, e1901052 (2019). Reports the use of phenothiazine derivative, MB, as a promising positive species in an acidic environment for aqueous RFBs.

    PubMed  Article  CAS  Google Scholar 

  88. Kwon, G. et al. Bio-inspired molecular redesign of a multi-redox catholyte for high-energy non-aqueous organic redox flow batteries. Chem 5, 2642–2656 (2019).

    CAS  Article  Google Scholar 

  89. Kwon, G. et al. Multi-redox molecule for high-energy redox flow batteries. Joule 2, 1771–1782 (2018).

    CAS  Article  Google Scholar 

  90. Weng, G.-M. et al. Asymmetric allyl-activation of organosulfides for high-energy reversible redox flow batteries. Energy Environ. Sci. 12, 2244–2252 (2019).

    CAS  Article  Google Scholar 

  91. Zhang, L., Zhao, B., Zhang, C. & Yu, G. Insights into the redox chemistry of organosulfides towards stable molecule design in nonaqueous energy storage systems. Angew. Chem. Int. Ed. 60, 4322–4328 (2021).

    CAS  Article  Google Scholar 

  92. Zhang, L. et al. Reversible redox chemistry in azobenzene-based organic molecules for high-capacity and long-life nonaqueous redox flow batteries. Nat. Commun. 11, 3843 (2020). One of the first demonstrations of the reversible redox chemistry of azobenzene molecules for high-performance non-aqueous RFBs.

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  93. Zu, X., Zhang, L., Qian, Y., Zhang, C. & Yu, G. Molecular engineering of azobenzene-based anolytes towards high-capacity aqueous redox flow batteries. Angew. Chem. Int. Ed. 59, 22163–22170 (2020).

    CAS  Article  Google Scholar 

  94. Sigel, H. & Martin, R. B. Coordinating properties of the amide bond. Stability and structure of metal ion complexes of peptides and related ligands. Chem. Rev. 82, 385–426 (1982).

    CAS  Article  Google Scholar 

  95. Häupler, B., Wild, A. & Schubert, U. S. Carbonyls: powerful organic materials for secondary batteries. Adv. Energy Mater. 5, 1402034 (2015).

    Article  CAS  Google Scholar 

  96. Ding, Y., Li, Y. & Yu, G. Exploring bio-inspired quinone-based organic redox flow batteries: a combined experimental and computational study. Chem 1, 790–801 (2016).

    CAS  Article  Google Scholar 

  97. Kwabi, D. G. et al. Alkaline quinone flow battery with long lifetime at pH 12. Joule 2, 1894–1906 (2018).

    CAS  Article  Google Scholar 

  98. Feng, R. et al. Reversible ketone hydrogenation and dehydrogenation for aqueous organic redox flow batteries. Science 372, 836–840 (2021). Introduces the idea of deprotonation to achieve reversible ketone reaction chemistry for aqueous RFBs.

    CAS  PubMed  Article  Google Scholar 

  99. Liang, Y., Tao, Z. & Chen, J. Organic electrode materials for rechargeable lithium batteries. Adv. Energy Mater. 2, 742–769 (2012).

    CAS  Article  Google Scholar 

  100. Duan, W. et al. A symmetric organic-based nonaqueous redox flow battery and its state of charge diagnostics by FTIR. J. Mater. Chem. A 4, 5448–5456 (2016).

    CAS  Article  Google Scholar 

  101. Sinclair, N. S., Poe, D., Savinell, R. F., Maginn, E. J. & Wainright, J. S. A nitroxide containing organic molecule in a deep eutectic solvent for flow battery applications. J. Electrochem. Soc. 168, 020527 (2021).

    CAS  Article  Google Scholar 

  102. DeBruler, C., Hu, B., Moss, J., Luo, J. & Liu, T. L. A sulfonate-functionalized viologen enabling neutral cation exchange, aqueous organic redox flow batteries toward renewable energy storage. ACS Energy Lett. 3, 663–668 (2018).

    CAS  Article  Google Scholar 

  103. Orita, A., Verde, M. G., Sakai, M. & Meng, Y. S. A biomimetic redox flow battery based on flavin mononucleotide. Nat. Commun. 7, 13230 (2016).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  104. Lin, K. et al. A redox-flow battery with an alloxazine-based organic electrolyte. Nat. Energy 1, 16102 (2016).

    CAS  Article  Google Scholar 

  105. Li, X. et al. Symmetry-breaking design of an organic iron complex catholyte for a long cyclability aqueous organic redox flow battery. Nat. Energy 6, 873–881 (2021).

    CAS  Article  Google Scholar 

  106. Zhao, Y. et al. Sustainable electrical energy storage through the ferrocene/ferrocenium redox reaction in aprotic electrolyte. Angew. Chem. Int. Ed. 126, 11216–11220 (2014). One of the first demonstrations of reversible redox chemistry of organometallic molecules for non-aqueous RFBs.

    Article  Google Scholar 

  107. Wei, X. et al. Towards high-performance nonaqueous redox flow electrolyte via ionic modification of active species. Adv. Energy Mater. 5, 1400678 (2015).

    Article  CAS  Google Scholar 

  108. Yu, J. et al. A robust anionic sulfonated ferrocene derivative for pH-neutral aqueous flow battery. Energy Storage Mater. 29, 216–222 (2020).

    Article  Google Scholar 

  109. Cabrera, P. J. et al. Complexes containing redox noninnocent ligands for symmetric, multielectron transfer nonaqueous redox flow batteries. J. Phys. Chem. C 119, 15882–15889 (2015).

    CAS  Article  Google Scholar 

  110. Sevov, C. S., Fisher, S. L., Thompson, L. T. & Sanford, M. S. Mechanism-based development of a low-potential, soluble, and cyclable multielectron anolyte for nonaqueous redox flow batteries. J. Am. Chem. Soc. 138, 15378–15384 (2016).

    CAS  PubMed  Article  Google Scholar 

  111. VanGelder, L. E., Pratt, H. D., Anderson, T. M. & Matson, E. M. Surface functionalization of polyoxovanadium clusters: generation of highly soluble charge carriers for nonaqueous energy storage. Chem. Commun. 55, 12247–12250 (2019).

    CAS  Article  Google Scholar 

  112. Brushett, F. R., Vaughey, J. T. & Jansen, A. N. An all-organic non-aqueous lithium-ion redox flow battery. Adv. Energy Mater. 2, 1390–1396 (2012).

    CAS  Article  Google Scholar 

  113. Duan, W. et al. “Wine-Dark Sea” in an organic flow battery: storing negative charge in 2,1,3-benzothiadiazole radicals leads to improved cyclability. ACS Energy Lett. 2, 1156–1161 (2017).

    CAS  Article  Google Scholar 

  114. Huang, J. et al. Liquid catholyte molecules for nonaqueous redox flow batteries. Adv. Energy Mater. 5, 1401782 (2015).

    Article  CAS  Google Scholar 

  115. Wang, G. et al. Exploring polycyclic aromatic hydrocarbons as an anolyte for nonaqueous redox flow batteries. J. Mater. Chem. A 6, 13286–13293 (2018).

    CAS  Article  Google Scholar 

  116. Wei, X. et al. A high-current, stable nonaqueous organic redox flow battery. ACS Energy Lett. 1, 705–711 (2016).

    CAS  Article  Google Scholar 

  117. Zhang, C., Zhang, L., Ding, Y., Guo, X. & Yu, G. Eutectic electrolytes for high-energy-density redox flow batteries. ACS Energy Lett. 3, 2875–2883 (2018).

    CAS  Article  Google Scholar 

  118. Zhang, C., Zhang, L. & Yu, G. Eutectic electrolytes as a promising platform for next-generation electrochemical energy storage. Acc. Chem. Res. 53, 1648–1659 (2020).

    CAS  PubMed  Article  Google Scholar 

  119. Chen, J.-J., Symes, M. D. & Cronin, L. Highly reduced and protonated aqueous solutions of [P2W18O62]6− for on-demand hydrogen generation and energy storage. Nat. Chem. 10, 1042–1047 (2018).

    CAS  PubMed  Article  Google Scholar 

  120. Zhang, L., Zhang, C., Ding, Y., Ramirez-Meyers, K. & Yu, G. A low-cost and high-energy hybrid iron-aluminum liquid battery achieved by deep eutectic solvents. Joule 1, 623–633 (2017). One of the first demonstrations of all-deep-eutectic-solvent-based flow batteries with coupling of the reaction of iron and aluminium.

    CAS  Article  Google Scholar 

  121. Zhang, C. et al. A sustainable redox-flow battery with an aluminum-based, deep-eutectic-solvent anolyte. Angew. Chem. Int. Ed. 56, 7454–7459 (2017).

    CAS  Article  Google Scholar 

  122. Zhang, C. et al. Highly concentrated phthalimide-based anolytes for organic redox flow batteries with enhanced reversibility. Chem 4, 2814–2825 (2018).

    CAS  Article  Google Scholar 

  123. Ding, Y. et al. Insights into hydrotropic solubilization for hybrid ion redox flow batteries. ACS Energy Lett. 3, 2641–2648 (2018).

    CAS  Article  Google Scholar 

  124. Cong, G., Zhou, Y., Li, Z. & Lu, Y.-C. A highly concentrated catholyte enabled by a low-melting-point ferrocene derivative. ACS Energy Lett. 2, 869–875 (2017).

    CAS  Article  Google Scholar 

  125. Shimizu, A. et al. Liquid quinones for solvent-free redox flow batteries. Adv. Mater. 29, 1606592 (2017).

    Article  CAS  Google Scholar 

  126. VanGelder, L. E., Cook, T. R. & Matson, E. M. Progress in the design of polyoxovanadate-alkoxides as charge carriers for nonaqueous redox flow batteries. Comments Inorg. Chem. 39, 51–89 (2019).

    CAS  Article  Google Scholar 

  127. Palmer, T. C. et al. A comparative review of metal-based charge carriers in nonaqueous flow batteries. ChemSusChem 14, 1214–1228 (2021).

    CAS  PubMed  Article  Google Scholar 

  128. Shrestha, A., Hendriks, K. H., Sigman, M. S., Minteer, S. D. & Sanford, M. S. Realization of an asymmetric non-aqueous redox flow battery through molecular design to minimize active species crossover and decomposition. Chem. Eur. J. 26, 5369–5373 (2020).

    CAS  PubMed  Article  Google Scholar 

  129. Tang, S. et al. Size effect of organosulfur and in situ formed oligomers enables high-utilization Na–organosulfur batteries. Adv. Mater. 33, 2100824 (2021).

    CAS  Article  Google Scholar 

  130. Hendriks, K. H. et al. High-performance oligomeric catholytes for effective macromolecular separation in nonaqueous redox flow batteries. ACS Cent. Sci. 4, 189–196 (2018).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  131. Janoschka, T. et al. An aqueous, polymer-based redox-flow battery using non-corrosive, safe, and low-cost materials. Nature 527, 78–81 (2015).

    CAS  PubMed  Article  Google Scholar 

  132. Burgess, M., Moore, J. S. & Rodríguez-López, J. Redox active polymers as soluble nanomaterials for energy storage. Acc. Chem. Res. 49, 2649–2657 (2016).

    CAS  PubMed  Article  Google Scholar 

  133. Winsberg, J. et al. Poly(TEMPO)/zinc hybrid-flow battery: a novel, “green,” high voltage, and safe energy storage system. Adv. Mater. 28, 2238–2243 (2016).

    CAS  PubMed  Article  Google Scholar 

  134. Winsberg, J. et al. TEMPO/phenazine combi-molecule: a redox-active material for symmetric aqueous redox-flow batteries. ACS Energy Lett. 1, 976–980 (2016).

    CAS  Article  Google Scholar 

  135. Dieterich, V. et al. Estimating the cost of organic battery active materials: a case study on anthraquinone disulfonic acid. Transl. Mater. Res. 5, 034001 (2018).

    Article  CAS  Google Scholar 

  136. Kwabi, D. G., Ji, Y. & Aziz, M. J. Electrolyte lifetime in aqueous organic redox flow batteries: a critical review. Chem. Rev. 120, 6467–6489 (2020).

    CAS  PubMed  Article  Google Scholar 

  137. Elgrishi, N. et al. A practical beginner’s guide to cyclic voltammetry. J. Chem. Educ. 95, 197–206 (2018).

    CAS  Article  Google Scholar 

  138. Wang, H. et al. Redox flow batteries: how to determine electrochemical kinetic parameters. ACS Nano 14, 2575–2584 (2020).

    CAS  PubMed  Article  Google Scholar 

  139. Luo, J. et al. Unraveling pH dependent cycling stability of ferricyanide/ferrocyanide in redox flow batteries. Nano Energy 42, 215–221 (2017).

    CAS  Article  Google Scholar 

  140. Yao, Y., Lei, J., Shi, Y., Ai, F. & Lu, Y.-C. Assessment methods and performance metrics for redox flow batteries. Nat. Energy 6, 582–588 (2021).

    Article  Google Scholar 

  141. Zhang, J. et al. An all-aqueous redox flow battery with unprecedented energy density. Energy Environ. Sci. 11, 2010–2015 (2018).

    CAS  Article  Google Scholar 

  142. Li, Z. & Lu, Y.-C. Polysulfide-based redox flow batteries with long life and low levelized cost enabled by charge-reinforced ion-selective membranes. Nat. Energy 6, 517–528 (2021). Reports a charge-reinforced Nafion membrane to achieve low crossover of polysulfide species, along with demonstrating long-life and low-cost aqueous RFBs.

    CAS  Article  Google Scholar 

  143. Wu, M. et al. Extremely stable anthraquinone negolytes synthesized from common precursors. Chem 6, 1432–1442 (2020).

    CAS  Article  Google Scholar 

  144. Machado, C. A. et al. Redox flow battery membranes: improving battery performance by leveraging structure–property relationships. ACS Energy Lett. 6, 158–176 (2020).

    Article  CAS  Google Scholar 

  145. Lu, W. et al. Porous membranes in secondary battery technologies. Chem. Soc. Rev. 46, 2199–2236 (2017).

    CAS  PubMed  Article  Google Scholar 

  146. Doris, S. E. et al. Macromolecular design strategies for preventing active-material crossover in non-aqueous all-organic redox-flow batteries. Angew. Chem. Int. Ed. 129, 1617–1621 (2017).

    Article  Google Scholar 

  147. Liu, W., Lu, W., Zhang, H. & Li, X. Aqueous flow batteries: research and development. Chem. Eur. J. 25, 1649–1664 (2019).

    CAS  PubMed  Article  Google Scholar 

  148. Goulet, M.-A. & Aziz, M. J. Flow battery molecular reactant stability determined by symmetric cell cycling methods. J. Electrochem. Soc. 165, A1466–A1477 (2018).

    CAS  Article  Google Scholar 

  149. Wu, W., Luo, J., Wang, F., Yuan, B. & Liu, T. L. A self-trapping, bipolar viologen bromide electrolyte for redox flow batteries. ACS Energy Lett. 6, 2891–2897 (2021).

    CAS  Article  Google Scholar 

  150. Zhao, E. W. et al. In situ NMR metrology reveals reaction mechanisms in redox flow batteries. Nature 579, 224–228 (2020). One of the first demonstrations of in situ NMR spectroscopy to study the detailed mechanism underlying the redox reaction of organic molecules in RFBs.

    CAS  PubMed  Article  Google Scholar 

  151. Wong, A. A., Rubinstein, S. M. & Aziz, M. J. Direct visualization of electrochemical reactions and heterogeneous transport within porous electrodes in operando by fluorescence microscopy. Cell Rep. Phys. Sci. 2, 100388 (2021).

    CAS  Article  Google Scholar 

  152. Zang, X. et al. Monitoring the state-of-charge of a vanadium redox flow battery with the acoustic attenuation coefficient: an in operando noninvasive method. Small Methods 3, 1900494 (2019).

    CAS  Article  Google Scholar 

  153. Sevov, C. S. et al. Physical organic approach to persistent, cyclable, low-potential electrolytes for flow battery applications. J. Am. Chem. Soc. 139, 2924–2927 (2017).

    CAS  PubMed  Article  Google Scholar 

  154. Yan, Y., Robinson, S. G., Sigman, M. S. & Sanford, M. S. Mechanism-based design of a high-potential catholyte enables a 3.2 V all-organic nonaqueous redox flow battery. J. Am. Chem. Soc. 141, 15301–15306 (2019).

    CAS  PubMed  Article  Google Scholar 

Download references

Acknowledgements

G.Y. acknowledges the financial support from the Welch Foundation award F-1861, Camille Dreyfus Teacher-Scholar Awards and Sloan Research Fellowship. R.F. and W.W. acknowledge the financial support from the US Department of Energy, Office of Electricity (under contract no. 70247) and Energy Storage Materials Initiative, which is a Laboratory-Directed Research and Development project at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogramme national laboratory operated by Battelle for the US Department of Energy under contract DE-AC05-76RL01830.

Author information

Authors and Affiliations

Authors

Contributions

G.Y., W.W. and L.Z. contemplated the topic and structure of the Review. L.Z. and R.F. conducted the literature research. All authors contributed to the discussion of content and wrote and edited the manuscript.

Corresponding authors

Correspondence to Wei Wang or Guihua Yu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Reviews Chemistry thanks E. Izgorodina, R. Suman and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Glossary

Rebalancing

Similar to regeneration, the recovery of active species following membrane crossover.

Electrode passivation

A decrease in active electrode surface area and an increase in contact and charge transfer resistance. Passivation is generally caused by the deposition and accumulation of side products on the surface of the electrode.

Hydrotropic effect

The use of suitable organic additives (for example, urea) to help increase the solubility of redox-active solute in aqueous solution through intermolecular interactions (for example, hydrogen bonding).

Capacity utilization

The percentage of delivered capacity over theoretical capacity.

Crossover effect

An effect, including, for example, capacity decay and side reactions, that occurs as a result of penetration of the redox species through the membrane.

Capacity fade rate

The loss in capacity, usually expressed as a percentage, over the total cycle number (% per cycle) or test time (% per day).

Regeneration

The recovery of active species after crossover without sacrificing capacity, which is similar to rebalancing.

Symmetric cell

A symmetric cell uses the same redox species (but exploits different oxidation states) on both sides of the cell. In the unbalanced configuration, using excess charge for the counter electrolyte minimizes its negative impact on the cell capacity decay.

Asymmetric cell

The asymmetric full-cell configuration uses different active materials with suitable potential difference in the catholyte and the anolyte, respectively. In a charge-unbalanced cell, one is the working electrolyte (limited charge) and the other serves as the counter electrolyte (excess charge).

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Zhang, L., Feng, R., Wang, W. et al. Emerging chemistries and molecular designs for flow batteries. Nat Rev Chem 6, 524–543 (2022). https://doi.org/10.1038/s41570-022-00394-6

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41570-022-00394-6

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing