Singlet oxygen generation as a major cause for parasitic reactions during cycling of aprotic lithium–oxygen batteries


Non-aqueous metal–oxygen batteries depend critically on the reversible formation/decomposition of metal oxides on cycling. Irreversible parasitic reactions cause poor rechargeability, efficiency, and cycle life, and have predominantly been ascribed to the reactivity of reduced oxygen species with cell components. These species, however, cannot fully explain the side reactions. Here we show that singlet oxygen forms at the cathode of a lithium–oxygen cell during discharge and from the onset of charge, and accounts for the majority of parasitic reaction products. The amount increases during discharge, early stages of charge, and charging at higher voltages, and is enhanced by the presence of trace water. Superoxide and peroxide appear to be involved in singlet oxygen generation. Singlet oxygen traps and quenchers can reduce parasitic reactions effectively. Awareness of the highly reactive singlet oxygen in non-aqueous metal–oxygen batteries gives a rationale for future research towards achieving highly reversible cell operation.

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Figure 1: Reactivity of the electrolyte with singlet oxygen.
Figure 2: Operando fluorescence spectroscopy during Li–O2 cell operation with electrolytes containing 9,10-dimethylanthracene (DMA) as singlet oxygen trap.
Figure 3: Operando NIR emission measurement during cycling of a Li–O2 cathode.
Figure 4: Ex situ analysis of Li–O2 cathodes run with electrolytes without or with 1O2 trap DMA or quencher DABCO.
Figure 5: Operando electrochemical mass spectrometry of Li–O2 cathodes run with electrolytes containing either no additive or the 1O2 trap DMA.


  1. 1

    Larcher, D. & Tarascon, J.-M. Towards greener and more sustainable batteries for electrical energy storage. Nat. Chem. 7, 19–29 (2014).

    Google Scholar 

  2. 2

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

    Google Scholar 

  3. 3

    Luntz, A. C. & McCloskey, B. D. Nonaqueous Li–air batteries: a status report. Chem. Rev. 114, 11721–11750 (2014).

    Google Scholar 

  4. 4

    Choi, N.-S. et al. Challenges facing lithium batteries and electrical double-layer capacitors. Angew. Chem. Int. Ed. 51, 9994–10024 (2012).

    Google Scholar 

  5. 5

    Lu, Y.-C. et al. Lithium-oxygen batteries: bridging mechanistic understanding and battery performance. Energy Environ. Sci. 6, 750–768 (2013).

    Google Scholar 

  6. 6

    Ren, X. & Wu, Y. A low-overpotential potassium–oxygen battery based on potassium superoxide. J. Am. Chem. Soc. 135, 2923–2926 (2013).

    Google Scholar 

  7. 7

    Walker, W. et al. A rechargeable Li–O2 battery using a lithium nitrate/N,N-dimethylacetamide electrolyte. J. Am. Chem. Soc. 135, 2076–2079 (2013).

    Google Scholar 

  8. 8

    Lim, H.-D. et al. Rational design of redox mediators for advanced Li–O2 batteries. Nat. Energy 1, 16066 (2016).

    Google Scholar 

  9. 9

    Bender, C. L., Hartmann, P., Vračar, M., Adelhelm, P. & Janek, J. On the thermodynamics, the role of the carbon cathode, and the cycle life of the sodium superoxide (NaO2) battery. Adv. Energy Mater. 4, 1301863 (2014).

    Google Scholar 

  10. 10

    Laoire, C. O., Mukerjee, S., Plichta, E. J., Hendrickson, M. A. & Abraham, K. M. Rechargeable lithium/TEGDME-LiPF6/O2 battery. J. Electrochem. Soc. 158, A302–A308 (2011).

    Google Scholar 

  11. 11

    Hassoun, J., Croce, F., Armand, M. & Scrosati, B. Investigation of the O2 electrochemistry in a polymer electrolyte solid-state cell. Angew. Chem. Int. Ed. 50, 2999–3002 (2011).

    Google Scholar 

  12. 12

    Younesi, R. et al. Ether based electrolyte, LiB(CN)4 salt and binder degradation in the Li–O2 battery studied by hard X-ray photoelectron spectroscopy (haxpes). J. Phys. Chem. C 116, 18597–18604 (2012).

    Google Scholar 

  13. 13

    Amanchukwu, C. V., Harding, J. R., Shao-Horn, Y. & Hammond, P. T. Understanding the chemical stability of polymers for lithium-air batteries. Chem. Mater. 27, 550–561 (2015).

    Google Scholar 

  14. 14

    Bryantsev, V. S. et al. The identification of stable solvents for nonaqueous rechargeable Li–air batteries. J. Electrochem. Soc. 160, A160–A171 (2013).

    Google Scholar 

  15. 15

    Xu, W. et al. The stability of organic solvents and carbon electrode in nonaqueous Li–O2 batteries. J. Power Sources 215, 240–247 (2012).

    Google Scholar 

  16. 16

    Ottakam Thotiyl, M. M. et al. A stable cathode for the aprotic Li–O2 battery. Nat. Mater. 12, 1050–1056 (2013).

    Google Scholar 

  17. 17

    Adams, B. D. et al. Towards a stable organic electrolyte for the lithium oxygen battery. Adv. Energy Mater. 5, 1400867 (2015).

    Google Scholar 

  18. 18

    Khetan, A., Luntz, A. & Viswanathan, V. Trade-offs in capacity and rechargeability in nonaqueous Li–O2 batteries: solution-driven growth versus nucleophilic stability. J. Phys. Chem. Lett. 6, 1254–1259 (2015).

    Google Scholar 

  19. 19

    Aetukuri, N. B. et al. Solvating additives drive solution-mediated electrochemistry and enhance toroid growth in non-aqueous Li–O2 batteries. Nat. Chem. 7, 50–56 (2015).

    Google Scholar 

  20. 20

    Black, R. et al. Screening for superoxide reactivity in Li–O2 batteries: effect on Li2O2/LiOH crystallization. J. Am. Chem. Soc. 134, 2902–2905 (2012).

    Google Scholar 

  21. 21

    McCloskey, B. D. et al. Twin problems of interfacial carbonate formation in nonaqueous Li–O2 batteries. J. Phys. Chem. Lett. 3, 997–1001 (2012).

    Google Scholar 

  22. 22

    Younesi, R., Hahlin, M., Björefors, F., Johansson, P. & Edström, K. Li–O2 battery degradation by lithium peroxide (Li2O2): a model study. Chem. Mater. 25, 77–84 (2012).

    Google Scholar 

  23. 23

    McCloskey, B. D. et al. Limitations in rechargeability of Li–O2 batteries and possible origins. J. Phys. Chem. Lett. 3, 3043–3047 (2012).

    Google Scholar 

  24. 24

    McCloskey, B. D. et al. Combining accurate O2 and Li2O2 assays to separate discharge and charge stability limitations in nonaqueous Li–O2 batteries. J. Phys. Chem. Lett. 4, 2989–2993 (2013).

    Google Scholar 

  25. 25

    Ottakam Thotiyl, M. M., Freunberger, S. A., Peng, Z. & Bruce, P. G. The carbon electrode in nonaqueous Li–O2 cells. J. Am. Chem. Soc. 135, 494–500 (2013).

    Google Scholar 

  26. 26

    Freunberger, S. A. et al. The lithium–oxygen battery with ether-based electrolytes. Angew. Chem. Int. Ed. 50, 8609–8613 (2011).

    Google Scholar 

  27. 27

    Carboni, M., Marrani, A. G., Spezia, R. & Brutti, S. 1,2-dimethoxyethane degradation thermodynamics in Li–O2 redox environments. Chem. Eur. J. 22, 17188–17203 (2016).

    Google Scholar 

  28. 28

    Wandt, J., Jakes, P., Granwehr, J., Gasteiger, H. A. & Eichel, R.-A. Singlet oxygen formation during the charging process of an aprotic lithium–oxygen battery. Angew. Chem. Int. Ed. 55, 6892–6895 (2016).

    Google Scholar 

  29. 29

    Alfano, A. J. & Christe, K. O. Singlet delta oxygen production from a gas–solid reaction. Angew. Chem. Int. Ed. 41, 3252–3254 (2002).

    Google Scholar 

  30. 30

    Li, Q. et al. A spectroscopic study on singlet oxygen production from different reaction paths using solid inorganic peroxides as starting materials. Bull. Korean Chem. Soc. 28, 1656–1660 (2007).

    Google Scholar 

  31. 31

    Schweitzer, C. & Schmidt, R. Physical mechanisms of generation and deactivation of singlet oxygen. Chem. Rev. 103, 1685–1758 (2003).

    Google Scholar 

  32. 32

    Ogilby, P. R. Singlet oxygen: there is indeed something new under the sun. Chem. Soc. Rev. 39, 3181–3209 (2010).

    Google Scholar 

  33. 33

    Aurbach, D., McCloskey, B. D., Nazar, L. F. & Bruce, P. G. Advances in understanding mechanisms underpinning lithium–air batteries. Nat. Energy 1, 16128 (2016).

    Google Scholar 

  34. 34

    Bryantsev, V. S. et al. Predicting solvent stability in aprotic electrolyte Li–air batteries: nucleophilic substitution by the superoxide anion radical (O2·−). J. Phys. Chem. A 115, 12399–12409 (2011).

    Google Scholar 

  35. 35

    Bryantsev, V. S. & Blanco, M. Computational study of the mechanisms of superoxide-induced decomposition of organic carbonate-based electrolytes. J. Phys. Chem. Lett. 2, 379–383 (2011).

    Google Scholar 

  36. 36

    Bryantsev, V. S. & Faglioni, F. Predicting autoxidation stability of ether- and amide-based electrolyte solvents for Li–air batteries. J. Phys. Chem. A 116, 7128–7138 (2012).

    Google Scholar 

  37. 37

    Khan, A. U. Direct spectral evidence of the generation of singlet molecular oxygen (1.Delta.g) in the reaction of potassium superoxide with water. J. Am. Chem. Soc. 103, 6516–6517 (1981).

    Google Scholar 

  38. 38

    Umezawa, N. et al. Novel fluorescent probes for singlet oxygen. Angew. Chem. Int. Ed. 38, 2899–2901 (1999).

    Google Scholar 

  39. 39

    Miyamoto, S., Martinez, G. R., Medeiros, M. H. G. & Di Mascio, P. Singlet molecular oxygen generated from lipid hydroperoxides by the russell mechanism: studies using 18O-labeled linoleic acid hydroperoxide and monomol light emission measurements. J. Am. Chem. Soc. 125, 6172–6179 (2003).

    Google Scholar 

  40. 40

    Young, R. H. & Brewer, D. R. in Singlet Oxygen. Reactions with Organic Compounds Polymers (eds Ranby, B. & Rabek, J. F. ) (Wiley, 1978).

    Google Scholar 

  41. 41

    Enko, B. et al. Singlet oxygen-induced photodegradation of the polymers and dyes in optical sensing materials and the effect of stabilizers on these processes. J. Phys. Chem. A 117, 8873–8882 (2013).

    Google Scholar 

  42. 42

    Chase, G. V. et al. Soluble oxygen evolving catalysts for rechargeable metal-air batteries. US patent 13/093,759 (2011).

  43. 43

    Chen, Y., Freunberger, S. A., Peng, Z., Fontaine, O. & Bruce, P. G. Charging a Li–O2 battery using a redox mediator. Nat. Chem. 5, 489–494 (2013).

    Google Scholar 

  44. 44

    Bryantsev, V. S., Blanco, M. & Faglioni, F. Stability of lithium superoxide LiO2 in the gas phase: computational study of dimerization and disproportionation reactions. J. Phys. Chem. A 114, 8165–8169 (2010).

    Google Scholar 

  45. 45

    Koppenol, W. H. Reactions involving singlet oxygen and the superoxide anion. Nature 262, 420–421 (1976).

    Google Scholar 

  46. 46

    Hummelshoj, J. S., Luntz, A. C. & Norskov, J. K. Theoretical evidence for low kinetic overpotentials in Li–O2 electrochemistry. J. Chem. Phys. 138, 034703 (2013).

    Google Scholar 

  47. 47

    Kang, S., Mo, Y., Ong, S. P. & Ceder, G. A facile mechanism for recharging Li2O2 in Li–O2 batteries. Chem. Mater. 25, 3328–3336 (2013).

    Google Scholar 

  48. 48

    Mo, Y., Ong, S. P. & Ceder, G. First-principles study of the oxygen evolution reaction of lithium peroxide in the lithium-air battery. Phys. Rev. B 84, 205446 (2011).

    Google Scholar 

  49. 49

    Snow, R. H. Thermodynamic Evaluation of the Possibility of Lithium Superoxide Production (Aerospace Medical Research Laboratories, 1965).

    Google Scholar 

  50. 50

    Khan, A. U. Activated oxygen: singlet molecular oxygen and superoxide anion. Photochem. Photobiol. 28, 615–626 (1978).

    Google Scholar 

  51. 51

    Borisov, S. M. et al. New NIR-emitting complexes of platinum(II) and palladium(II) with fluorinated benzoporphyrins. J. Photochem. Photobiol. A 201, 128–135 (2009).

    Google Scholar 

  52. 52

    Chen, Y., Freunberger, S. A., Peng, Z., Bardé, F. & Bruce, P. G. Li–O2 battery with a dimethylformamide electrolyte. J. Am. Chem. Soc. 134, 7952–7957 (2012).

    Google Scholar 

  53. 53

    Peng, Z., Freunberger, S. A., Chen, Y. & Bruce, P. G. A reversible and higher-rate Li–O2 battery. Science 337, 563–566 (2012).

    Google Scholar 

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S.A.F. is indebted to the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 636069). We further gratefully acknowledge funding from the Austrian Federal Ministry of Economy, Family and Youth and the Austrian National Foundation for Research, Technology and Development and initial funding from the Austrian Science Fund (FWF, Project No. P26870-N19). The authors thank R. Saf for help with the MS, R. Breinbauer for discussions about the reaction mechanism, S. Landgraf for help with the NIR measurement, and J. Schlegl for manufacturing instrumentation for the methods used.

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N.M. performed the main part of the experiments and analysed the results. B.S., S.G. and C.L. performed cell cycling, MS and NMR experiments. G.A.S. did HPLC analysis. S.A.F., D.K., C.S., O.F. and M.L. discussed the reaction mechanisms. S.M.B. supervised the optical experiments. S.A.F. conceived and directed the research, set up and performed experiments, analysed the results and wrote the manuscript with help of the other authors. All authors contributed to the discussion and interpretation of the results.

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Correspondence to Stefan A. Freunberger.

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Supplementary Figures 1–15, Supplementary Table 1, Supplementary Discussion, Supplementary References (PDF 946 kb)

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Mahne, N., Schafzahl, B., Leypold, C. et al. Singlet oxygen generation as a major cause for parasitic reactions during cycling of aprotic lithium–oxygen batteries. Nat Energy 2, 17036 (2017).

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