Skip to main content

Thank you for visiting 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.

Polypeptide organic radical batteries


In only a few decades, lithium-ion batteries have revolutionized technologies, enabling the proliferation of portable devices and electric vehicles1, with substantial benefits for society. However, the rapid growth in technology has highlighted the ethical and environmental challenges of mining lithium, cobalt and other mineral ore resources, and the issues associated with the safe usage and non-hazardous disposal of batteries2. Only a small fraction of lithium-ion batteries are recycled, further exacerbating global material supply of strategic elements3,4,5. A potential alternative is to use organic-based redox-active materials6,7,8 to develop rechargeable batteries that originate from ethically sourced, sustainable materials and enable on-demand deconstruction and reconstruction. Making such batteries is challenging because the active materials must be stable during operation but degradable at end of life. Further, the degradation products should be either environmentally benign or recyclable for reconstruction into a new battery. Here we demonstrate a metal-free, polypeptide-based battery, in which viologens and nitroxide radicals are incorporated as redox-active groups along polypeptide backbones to function as anode and cathode materials, respectively. These redox-active polypeptides perform as active materials that are stable during battery operation and subsequently degrade on demand in acidic conditions to generate amino acids, other building blocks and degradation products. Such a polypeptide-based battery is a first step to addressing the need for alternative chemistries for green and sustainable batteries in a future circular economy.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Fig. 1: A polypeptide-based organic radical battery.
Fig. 2: Syntheses of redox-active polypeptides.
Fig. 3: Cyclic voltammograms of redox-active polypeptides.
Fig. 4: Electrochemical response of polypeptide composite half-cells and full cell.
Fig. 5: Degradation of viologen and biTEMPO polypeptides.

Data availability

All data generated or analysed during this study are included in paper and its Supplementary InformationSource data are provided with this paper.


  1. Lopez, J., Mackanic, D. G., Cui, Y. & Bao, Z. Designing polymers for advanced battery chemistries. Nat. Rev. Mater. 4, 312–330 (2019).

    Article  CAS  ADS  Google Scholar 

  2. Turcheniuk, K., Bondarev, D., Singhal, V. & Yushin, G. Ten years left to redesign lithium-ion batteries. Nature 559, 467–470 (2018).

    Article  CAS  PubMed  ADS  Google Scholar 

  3. Zeng, X., Li, J. & Singh, N. Recycling of spent lithium-ion battery: a critical review. Crit. Rev. Environ. Sci. Technol. 44, 1129–1165 (2014).

    Article  CAS  Google Scholar 

  4. Olivetti, E. A., Ceder, G., Gaustad, G. G. & Fu, X. Lithium-ion battery supply chain considerations: analysis of potential bottlenecks in critical metals. Joule 1, 229–243 (2017).

    Article  Google Scholar 

  5. Wild, A., Strumpf, M., Häupler, B., Hager, M. D. & Schubert, U. S. All-organic battery composed of thianthrene- and TCAQ-based polymers. Adv. Energy Mater. 7, 1601415 (2017).

    Article  CAS  Google Scholar 

  6. Banza Lubaba Nkulu, C. et al. Sustainability of artisanal mining of cobalt in DR Congo. Nat. Sustain. 1, 495–504 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  7. Koshika, K., Chikushi, N., Sano, N., Oyaizu, K. & Nishide, H. A TEMPO-substituted polyacrylamide as a new cathode material: an organic rechargeable device composed of polymer electrodes and aqueous electrolyte. Green Chem. 12, 1573–1575 (2010).

    Article  CAS  Google Scholar 

  8. Esquivel, J. P. et al. A metal-free and biotically degradable battery for portable single-use applications. Adv. Energy Mater. 7, 1700275 (2017).

    Article  CAS  Google Scholar 

  9. Friebe, C., Lex-Balducci, A. & Schubert, U. S. Sustainable energy storage: recent trends and developments toward fully organic batteries. ChemSusChem 12, 4093 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Janoschka, T., Hager, M. D. & Schubert, U. S. Powering up the future: radical polymers for battery applications. Adv. Mater. 24, 6397–6409 (2012).

    Article  CAS  PubMed  Google Scholar 

  11. Kim, J., Kim, J. H. & Ariga, K. Redox-active polymers for energy storage nanoarchitectonics. Joule 1, 739–768 (2017).

    Article  CAS  Google Scholar 

  12. Tomlinson, E. P., Hay, M. E. & Boudouris, B. W. Radical polymers and their application to organic electronic devices. Macromolecules 47, 6145–6158 (2014).

    Article  CAS  ADS  Google Scholar 

  13. Lutkenhaus, J. A radical advance for conducting polymers. Science 359, 1334–1335 (2018).

    Article  CAS  PubMed  ADS  Google Scholar 

  14. Joo, Y., Agarkar, V., Sung, S. H., Savoie, B. M. & Boudouris, B. W. A nonconjugated radical polymer glass with high electrical conductivity. Science 359, 1391–1395 (2018).

    Article  CAS  PubMed  ADS  Google Scholar 

  15. Coates, G. W. & Getzler, Y. D. Y. L. Chemical recycling to monomer for an ideal, circular polymer economy. Nat. Rev. Mater. 5, 501–516 (2020).

    Article  CAS  ADS  Google Scholar 

  16. Muench, S. et al. Polymer-based organic batteries. Chem. Rev. 116, 9438–9484 (2016).

    Article  CAS  PubMed  Google Scholar 

  17. Zhang, K., Monteiro, M. J. & Jia, Z. Stable organic radical polymers: synthesis and applications. Polym. Chem. 7, 5589–5614 (2016).

    Article  CAS  Google Scholar 

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

    Article  CAS  PubMed  ADS  Google Scholar 

  19. Koshika, K., Sano, N., Oyaizu, K. & Nishide, H. An aqueous, electrolyte-type, rechargeable device utilizing a hydrophilic radical polymer-cathode. Macromol. Chem. Phys. 210, 1989–1995 (2009).

    Article  CAS  Google Scholar 

  20. Sano, N. et al. Polyviologen hydrogel with high-rate capability for anodes toward an aqueous electrolyte-type and organic-based rechargeable device. ACS Appl. Mater. Interfaces 5, 1355–1361 (2013).

    Article  CAS  PubMed  Google Scholar 

  21. Suga, T., Ohshiro, H., Sugita, S., Oyaizu, K. & Nishide, H. Emerging n-type redox-active radical polymer for a totally organic polymer-based rechargeable Battery. Adv. Mater. 21, 1627–1630 (2009).

    Article  CAS  Google Scholar 

  22. Suga, T., Sugita, S., Ohshiro, H., Oyaizu, K. & Nishide, H. p- and n-type bipolar redox-active radical polymer: toward totally organic polymer-based rechargeable devices with variable configuration. Adv. Mater. 23, 751–754 (2011).

    Article  CAS  PubMed  Google Scholar 

  23. Oka, K., Kato, R., Oyaizu, K. & Nishide, H. Poly(vinyldibenzothiophenesulfone): its redox capability at very negative potential toward an all-organic rechargeable device with high-energy density. Adv. Funct. Mater. 28, 1805858 (2018).

    Article  CAS  Google Scholar 

  24. Qu, J. et al. Synthesis and properties of DNA complexes containing 2,2,6,6-tetramethyl-1-piperidinoxy (TEMPO) moieties as organic radical battery materials. Chemistry 14, 3250–3259 (2008).

    Article  CAS  PubMed  Google Scholar 

  25. Ibe, T., Frings, R. B., Lachowicz, A., Kyo, S. & Nishide, H. Nitroxide polymer networks formed by Michael addition: on site-cured electrode-active organic coating. Chem. Commun. 46, 3475–3477 (2010).

    Article  CAS  Google Scholar 

  26. Qu, J. et al. Helical polyacetylenes carrying 2,2,6,6-tetramethyl-1-piperidinyloxy and 2,2,5,5-tetramethyl-1-pyrrolidinyloxy moieties: their synthesis, properties, and function. J. Polym. Sci. A 45, 5431–5445 (2007).

    Article  CAS  Google Scholar 

  27. Otaki, M. & Goto, H. Helical spin polymer with magneto-electro-optical activity. Macromolecules 52, 3199–3209 (2019).

    Article  CAS  ADS  Google Scholar 

  28. Hatakeyama-Sato, K., Wakamatsu, H., Katagiri, R., Oyaizu, K. & Nishide, H. An ultrahigh output rechargeable electrode of a hydrophilic radical polymer/nanocarbon hybrid with an exceptionally large current density beyond 1 A cm−2. Adv. Mater. 30, 1800900 (2018).

    Article  CAS  Google Scholar 

  29. Hiejima, T. & Kaneko, J. Spiral configuration of nitroxide radicals along the polypeptide helix and their magnetic properties. Macromolecules 46, 1713–1722 (2013).

    Article  CAS  ADS  Google Scholar 

  30. Belshaw, P. J., Mzengeza, S. & Lajoie, G. A. Chlorotrimethylsilane mediated formation of ω-allyl esters of aspartic and glutamic acids. Synth. Commun. 20, 3157–3160 (1990).

    Article  CAS  Google Scholar 

  31. Deming, T. J. Synthesis of side-chain modified polypeptides. Chem. Rev. 116, 786–808 (2016).

    Article  CAS  PubMed  Google Scholar 

  32. Fan, J. et al. Construction of a versatile and functional nanoparticle platform derived from a helical diblock copolypeptide-based biomimetic polymer. Polym. Chem. 5, 3977–3981 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Engler, A. C., Lee, H.-i. & Hammond, P. T. Highly efficient “grafting onto” a polypeptide backbone using click chemistry. Angew. Chem. Int. Ed. 48, 9334–9338 (2009).

    Article  CAS  Google Scholar 

  34. Hoyle, C. E. & Bowman, C. N. Thiol–ene click chemistry. Angew. Chem. Int. Ed. 49, 1540–1573 (2010).

    Article  CAS  Google Scholar 

  35. Hansen, K.-A. et al. A methoxyamine-protecting group for organic radical battery materials—an alternative approach. ChemSusChem 13, 2386 (2020).

    Article  CAS  PubMed  Google Scholar 

  36. Galbo, J. P. Process for preparing N-methoxy derivatives of 4-hydroxy-2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidone. US patent 5374729A (1994).

  37. Deming, T. J. Noodle gels for cells. Nat. Mater. 9, 535–536 (2010).

    Article  CAS  PubMed  ADS  Google Scholar 

  38. Lalatsa, A., Schätzlein, A. G., Mazza, M., Le, T. B. H. & Uchegbu, I. F. Amphiphilic poly(l-amino acids) — new materials for drug delivery. J. Control. Release 161, 523–536 (2012).

    Article  CAS  PubMed  Google Scholar 

  39. Matson, J. B. & Stupp, S. I. Self-assembling peptide scaffolds for regenerative medicine. Chem. Commun. 48, 26–33 (2012).

    Article  CAS  Google Scholar 

  40. Shpilevaya, I. & Foord, J. S. Electrochemistry of methyl viologen and anthraquinonedisulfonate at diamond and diamond powder electrodes: the influence of surface chemistry. Electroanalysis 26, 2088–2099 (2014).

    Article  CAS  Google Scholar 

  41. Bard, A. J. & Faulkner, L. R. Electrochemical Methods: Fundamentals and Applications 2nd edn, Ch. 6 (Wiley, 2000).

  42. Bugnon, L., Morton, C. J. H., Novak, P., Vetter, J. & Nesvadba, P. Synthesis of poly(4-methacryloyloxy-TEMPO) via group-transfer polymerization and its evaluation in organic radical battery. Chem. Mater. 19, 2910–2914 (2007).

    Article  CAS  Google Scholar 

  43. Janoschka, T. et al. Reactive inkjet printing of cathodes for organic radical batteries. Adv. Energy Mater. 3, 1025–1028 (2013).

    Article  CAS  Google Scholar 

  44. Vlad, A., Rolland, J., Hauffman, G., Ernould, B. & Gohy, J.-F. Melt-polymerization of TEMPO methacrylates with nano carbons enables superior battery materials. ChemSusChem 8, 1692–1696 (2015).

    Article  CAS  PubMed  Google Scholar 

  45. Lutkenhaus, J. et al. Solution-processable thermally crosslinked organic radical polymer battery cathodes. ChemSusChem 13, 2371 (2020).

    Article  PubMed  CAS  Google Scholar 

  46. Elsabahy, M., Samarajeewa, S., Raymond, J. E., Clark, C. & Wooley, K. L. Shell-crosslinked knedel-like nanoparticles induce lower immunotoxicity than their non-crosslinked analogs. J. Mater. Chem. B 1, 5241–5255 (2013).

    Article  CAS  Google Scholar 

Download references


This work was financially supported by the National Science Foundation (DMR-1507429, DMR-1905818, CHE-2003771 and DMREF-1629094; K.L.W. and T.P.N.; synthesis and structural characterization), the Welch Foundation (A-0001, K.L.W.; A-1717, C.-H.Y.) and the US Department of Energy Office of Science (DE-SC0014006; J.L.L. and A.D.E.; electrochemical measurements). A.D.E. acknowledges support by a National Science Foundation Graduate Research Fellowship.

Author information

Authors and Affiliations



T.P.N. and A.D.E. contributed equally to this work. T.P.N., A.D.E., J.L.L. and K.L.W. developed the study. T.P.N. synthesized and structurally characterized the viologen and biTEMPO polypeptides. A.D.E. performed the electrochemical characterization of the materials. XPS and scanning electron microscopy data were obtained by N.K., electron paramagnetic resonance by S.W. and thermal characterization by A.D.E. and D.K.T. The degradation study was done by T.P.N., with help from Y.H.R. for mass spectrometry. The cytotoxicity study was done by S.K. and S.-M.L. The manuscript was written by T.P.N. and A.D.E., with help from J.F., R.A.L., X.H., L.S., C.-H.Y., J.L.L. and K.L.W.

Corresponding authors

Correspondence to Jodie L. Lutkenhaus or Karen L. Wooley.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature thanks Jung Ho Kim, David Mercerreyes and Ulrich Schubert for their contribution to the peer review of this work.

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

Extended data figures and tables

Extended Data Fig. 1 Molecular structures of viologen and biTEMPO analogues


Extended Data Fig. 2 Electrochemistry assemblies.

a, The half sandwich cell: viol-Cl or biTEMPO polypeptide composite working electrode and lithium metal reference electrode, with a filter-paper separator. b, The full sandwich cell: viol-Cl polypeptide composite working electrode and biTEMPO polypeptide composite reference electrode, with a filter-paper separator.

Extended Data Fig. 3 Electrochemical performance of full cell without polypeptide active material as a control.

Electrochemical characterization of a PVDF + CB symmetric full cell is shown, including cyclic voltammograms (i), charge–discharge curves (ii) and cycling response at 1C (iii) (PVDF + CB composite electrode, 0.5 M TBACF3SO3 in PC and filter paper, PVDF + CB composite electrode). The composite electrodes were cast in an identical manner to the polypeptide composite electrodes, with a composition of 86 wt% CB and 14 wt% PVDF on ITO-coated glass substrates. After 250 cycles, the capacity was 1.7 mA h g−1, whereas the capacity of the polypeptide-based full cell was 7.5 mA h g−1 (Fig. 4g–i).

Extended Data Fig. 4 Electrode morphology before and after testing the full cell.

a, b, Scanning electron micrographs of the viol-Cl polypeptide composite electrode (a) and the biTEMPO polypeptide composite electrode (b), before (i) and after (ii) 50 charge–discharge cycles in the full sandwich cell configuration (viol-Cl polypeptide composite electrode, 0.5 M TBACF3SO3 in PC and filter paper, biTEMPO polypeptide composite electrode).

Source data

Extended Data Fig. 5 Cell viability study.

Dose–response curves for redox-active polypeptides. Data are expressed as mean ± s.d. of three determinations. The statistical analysis was performed using GraphPad Prism, with the black lines representing four-parameter fits.

Source data

Extended Data Fig. 6 Cell viability study.

Dose–response curves for redox-active polypeptides after acid degradation. Data are expressed as mean ± s.d. of three determinations. The statistical analysis was performed using GraphPad Prism, with the black lines representing four-parameter fits.

Source data

Extended Data Fig. 7 Cell viability study.

Comparison of IC50 values of viologen polypeptide, biTEMPO polypeptide, viologen analogue, biTEMPO analogue and their degraded products.

Source data

Extended Data Table 1 Performance of selected polymer-based batteries
Extended Data Table 2 Elemental analysis of the synthesized polymers
Extended Data Table 3 Degradation conditions used for the viologen and biTEMPO polypeptides

Supplementary information

Supplementary Information

This file contains supplementary experimental procedures for additional electrochemistry characterizations and the synthetic details for the viologen and BiTEMPO polypeptides and their analogs. Spectral data (NMR and FTIR) is provided for all the synthesized species. Supplementary Figures are provided for electrochemical, degradation, and cell viability studies.

Source data

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nguyen, T.P., Easley, A.D., Kang, N. et al. Polypeptide organic radical batteries. Nature 593, 61–66 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


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