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An aqueous, polymer-based redox-flow battery using non-corrosive, safe, and low-cost materials

Nature volume 527, pages 7881 (05 November 2015) | Download Citation


For renewable energy sources such as solar, wind, and hydroelectric to be effectively used in the grid of the future, flexible and scalable energy-storage solutions are necessary to mitigate output fluctuations1. Redox-flow batteries (RFBs) were first built in the 1940s2 and are considered a promising large-scale energy-storage technology1,3,4. A limited number of redox-active materials4,5,6,7,8,9,10—mainly metal salts, corrosive halogens, and low-molar-mass organic compounds—have been investigated as active materials, and only a few membrane materials3,5,11,12,13,14, such as Nafion, have been considered for RFBs. However, for systems that are intended for both domestic and large-scale use, safety and cost must be taken into account as well as energy density and capacity, particularly regarding long-term access to metal resources, which places limits on the lithium-ion-based and vanadium-based RFB development15,16. Here we describe an affordable, safe, and scalable battery system, which uses organic polymers as the charge-storage material in combination with inexpensive dialysis membranes, which separate the anode and the cathode by the retention of the non-metallic, active (macro-molecular) species, and an aqueous sodium chloride solution as the electrolyte. This water- and polymer-based RFB has an energy density of 10 watt hours per litre, current densities of up to 100 milliamperes per square centimetre, and stable long-term cycling capability. The polymer-based RFB we present uses an environmentally benign sodium chloride solution and cheap, commercially available filter membranes instead of highly corrosive acid electrolytes and expensive membrane materials.

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We acknowledge the European Regional Development Fund for Thuringia (EFRE), the Thüringer Aufbaubank (TAB), the Thuringian Ministry for Economic Affairs, Science and Digital Society (TMWWdG), and the Fonds der Chemischen Industrie for financial support. We thank J. Stammer, C. Oder, K. Wolkersdörfer, C. Stolze, C. Schmerbauch, B. Häupler, M. Wagner, T. Buś, A. Ignaszak, and F. Schacher for their assistance and comments.

Author information


  1. Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany

    • Tobias Janoschka
    • , Christian Friebe
    • , Sabine Morgenstern
    • , Hannes Hiller
    • , Martin D. Hager
    •  & Ulrich S. Schubert
  2. Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany

    • Tobias Janoschka
    • , Christian Friebe
    • , Sabine Morgenstern
    • , Hannes Hiller
    • , Martin D. Hager
    •  & Ulrich S. Schubert
  3. JenaBatteries GmbH, Botzstrasse 5, 07743 Jena, Germany

    • Norbert Martin
    •  & Udo Martin


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T.J., M.D.H., and U.S.S. conceived the studies. N.M., C.F., and T.J. contributed to performing all electrochemical experiments and interpreting the results. S.M. and H.H. performed synthesis under the supervision of T.J. The test cell was designed by U.M. All authors discussed the results and commented on the manuscript. T.J., C.F., M.D.H., and U.S.S wrote the manuscript.

Competing interests

U.S.S. is associated with JenaBatteries GmbH as a scientific advisor and T.J., M.D.H. and U.S.S. are co-founders of the company. The intellectual property based upon the present data will be transferred from the Friedrich Schiller University Jena to the JenaBatteries GmbH.

Corresponding author

Correspondence to Ulrich S. Schubert.

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