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.

Operando decoding of chemical and thermal events in commercial Na(Li)-ion cells via optical sensors


Monitoring the dynamic chemical and thermal state of a cell during operation is crucial to making meaningful advancements in battery technology as safety and reliability cannot be compromised. Here we demonstrate the feasibility of incorporating optical fibre Bragg grating sensors into commercial 18650 cells. By adjusting fibre morphologies, wavelength changes associated with both temperature and pressure are decoupled with high accuracy, which allows tracking of chemical events such as solid electrolyte interphase formation and structural evolution. We also demonstrate how multiple sensors are used to determine the heat generated by the cell without resorting to microcalorimetry. Unlike with conventional isothermal calorimetry, the cell’s heat capacity contribution is readily assessed, allowing for full parametrization of the thermal model. Collectively, these findings offer a scalable solution for screening electrolyte additives, rapidly identifying the best formation processes of commercial cells and designing battery thermal management systems with enhanced safety.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Concept of optical fibre sensing inside the battery.
Fig. 2: Probing temperature and pressure dynamics inside batteries and its implications on the SEI.
Fig. 3: Methodology of the optical sensing calorimetry and its benchmark with isothermal calorimetry.
Fig. 4: Enthalpy potentials.
Fig. 5: Decomposing the heat contributions at 1C.
Fig. 6: Quantifying the SEI formation.

Data availability

All relevant data are included in the paper and its Supplementary Information.


  1. Armand, M. & Tarascon, J.-M. Building better batteries. Nature 451, 652–657 (2008).

    Google Scholar 

  2. Grey, C. & Tarascon, J.-M. Sustainability and in situ monitoring in battery development. Nat. Mater. 16, 45–56 (2017).

    Article  Google Scholar 

  3. Bright, C. T. et al. Remarks on “On reversible lead batteries and their use for electric lighting”. J. Soc. Telegr. Eng. Electr. 16, 184–218 (1887).

    Google Scholar 

  4. Lamoureux Jr, T. L. Flight Proofing Test Report for Main Missile Remotely Activated Primary Battery, ESB DWG. NO. 27-06359-3 (General Dynamics/Astronautics San Diego CA, 1959).

  5. Jasinski, L. Rapid battery charging system and method. US patent 3,852,652 (1974).

  6. Louli, A., Ellis, L. & Dahn, J. Operando pressure measurements reveal solid electrolyte interphase growth to rank Li-ion cell performance. Joule 3, 745–761 (2019).

    Article  Google Scholar 

  7. Worrell, C. & Redfern, B. Acoustic emission studies of the breakdown of beta-alumina under conditions of sodium ion transport. J. Mater. Sci. 13, 1515–1520 (1978).

    Article  Google Scholar 

  8. Day, R. et al. Differential thermal analysis of Li-ion cells as an effective probe of liquid electrolyte evolution during aging. J. Electrochem. Soc. 162, A2577–A2581 (2015).

    Article  Google Scholar 

  9. Keddam, M., Stoynov, Z. & Takenouti, H. Impedance measurement on Pb/H2SO4 batteries. J. Appl. Electrochem. 7, 539–544 (1977).

    Article  Google Scholar 

  10. Liebhart, B., Komsiyska, L. & Endisch, C. Passive impedance spectroscopy for monitoring lithium-ion battery cells during vehicle operation. J. Power Sources 449, 227297 (2020).

    Article  Google Scholar 

  11. Schmidt, J. P. et al. Measurement of the internal cell temperature via impedance: evaluation and application of a new method. J. Power Sources 243, 110–117 (2013).

    Article  Google Scholar 

  12. Schmidt, J. P., Manka, D., Klotz, D. & Ivers-Tiffée, E. Investigation of the thermal properties of a Li-ion pouch-cell by electrothermal impedance spectroscopy. J. Power Sources 196, 8140–8146 (2011).

    Article  Google Scholar 

  13. Forgez, C., Do, D. V., Friedrich, G., Morcrette, M. & Delacourt, C. Thermal modeling of a cylindrical LiFePO4/graphite lithium-ion battery. J. Power Sources 195, 2961–2968 (2010).

    Article  Google Scholar 

  14. Yang, G., Leitão, C., Li, Y., Pinto, J. & Jiang, X. Real-time temperature measurement with fiber Bragg sensors in lithium batteries for safety usage. Measurement 46, 3166–3172 (2013).

    Article  Google Scholar 

  15. Cheng, X. & Pecht, M. In situ stress measurement techniques on li-ion battery electrodes: a review. Energies 10, 591 (2017).

    Article  Google Scholar 

  16. Peng, J. et al. High precision strain monitoring for lithium ion batteries based on fiber Bragg grating sensors. J. Power Sources 433, 226692 (2019).

    Article  Google Scholar 

  17. Nascimento, M., Paixão, T., Ferreira, M. S. & Pinto, J. L. Thermal mapping of a lithium polymer batteries pack with FBGs network. Batteries 4, 67 (2018).

    Article  Google Scholar 

  18. Raghavan, A. et al. Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 1: Cell embedding method and performance. J. Power Sources 341, 466–473 (2017).

    Article  Google Scholar 

  19. Ganguli, A. et al. Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 2: Internal cell signals and utility for state estimation. J. Power Sources 341, 474–482 (2017).

    Article  Google Scholar 

  20. Nascimento, M. et al. Internal strain and temperature discrimination with optical fiber hybrid sensors in Li-ion batteries. J. Power Sources 410, 1–9 (2019).

    Article  Google Scholar 

  21. Bernardi, D., Pawlikowski, E. & Newman, J. A general energy balance for battery systems. J. Electrochem. Soc. 132, 5–12 (1985).

    Article  Google Scholar 

  22. Thomas, K. E. & Newman, J. Thermal modeling of porous insertion electrodes. J. Electrochem. Soc. 150, A176–A192 (2003).

    Article  Google Scholar 

  23. Downie, L., Hyatt, S. & Dahn, J. The impact of electrolyte composition on parasitic reactions in lithium ion cells charged to 4.7 V determined using isothermal microcalorimetry. J. Electrochem. Soc. 163, A35–A42 (2016).

    Article  Google Scholar 

  24. Assat, G., Glazier, S. L., Delacourt, C. & Tarascon, J.-M. Probing the thermal effects of voltage hysteresis in anionic redox-based lithium-rich cathodes using isothermal calorimetry. Nat. Energy 4, 647–656 (2019).

    Article  Google Scholar 

  25. Shen, Z., Cao, L., Rahn, C. D. & Wang, C.-Y. Least squares galvanostatic intermittent titration technique (LS-GITT) for accurate solid phase diffusivity measurement. J. Electrochem. Soc. 160, A1842–A1846 (2013).

    Article  Google Scholar 

  26. Srinivasan, V. & Newman, J. Discharge model for the lithium iron-phosphate electrode. J. Electrochem. Soc. 151, A1517–A1529 (2004).

    Article  Google Scholar 

  27. Maher, K. & Yazami, R. A study of lithium ion batteries cycle aging by thermodynamics techniques. J. Power Sources 247, 527–533 (2014).

    Article  Google Scholar 

  28. Bianchini, M. et al. Comprehensive investigation of the Na3V2(PO4)2F3–NaV2(PO4)2F3 system by operando high resolution synchrotron X-ray diffraction. Chem. Mater. 27, 3009–3020 (2015).

    Article  Google Scholar 

  29. Berlinsky, A., Unruh, W., McKinnon, W. & Haering, R. Theory of lithium ordering in LixTiS2. Solid State Commun. 31, 135–138 (1979).

    Article  Google Scholar 

  30. Yan, G. et al. Assessment of the electrochemical stability of carbonate-based electrolytes in Na-ion batteries. J. Electrochem. Soc. 165, A1222–A1230 (2018).

    Article  Google Scholar 

  31. Hall, D. S., Glazier, S. L. & Dahn, J. R. Isothermal microcalorimetry as a tool to study solid-electrolyte interphase formation in lithium-ion cells. Phys. Chem. Chem. Phys. 18, 11383–11390 (2016).

    Article  Google Scholar 

  32. Cometto, C., Yan, G., Mariyappan, S. & Tarascon, J.-M. Means of using cyclic voltammetry to rapidly design a stable DMC-Based electrolyte for Na-ion batteries. J. Electrochem. Soc. 166, A3723–A3730 (2019).

    Article  Google Scholar 

  33. Cha, J., Han, J.-G., Hwang, J., Cho, J. & Choi, N.-S. Mechanisms for electrochemical performance enhancement by the salt-type electrolyte additive, lithium difluoro (oxalato) borate, in high-voltage lithium-ion batteries. J. Power Sources 357, 97–106 (2017).

    Article  Google Scholar 

  34. Qi, X. et al. Lifetime limit of tris (trimethylsilyl) phosphite as electrolyte additive for high voltage lithium ion batteries. RSC Adv. 6, 38342–38349 (2016).

    Article  Google Scholar 

  35. David, N., Wild, P., Jensen, J., Navessin, T. & Djilali, N. Simultaneous in situ measurement of temperature and relative humidity in a PEMFC using optical fiber sensors. J. Electrochem. Soc. 157, B1173–B1179 (2010).

    Article  Google Scholar 

  36. Yan, G. et al. A new electrolyte formulation for securing high temperature cycling and storage performances of Na‐ion batteries. Adv. Energy Mater. 9, 1901431 (2019).

    Article  Google Scholar 

  37. Htein, L., Liu, Z., Gunawardena, D. & Tam, H.-Y. Single-ring suspended fiber for Bragg grating based hydrostatic pressure sensing. Opt. Express 27, 9655–9664 (2019).

    Article  Google Scholar 

  38. Krause, L., Jensen, L. & Dahn, J. Measurement of parasitic reactions in Li ion cells by electrochemical calorimetry. J. Electrochem. Soc. 159, A937–A943 (2012).

    Article  Google Scholar 

  39. Downie, L., Hyatt, S., Wright, A. & Dahn, J. Determination of the time dependent parasitic heat flow in lithium ion cells using isothermal microcalorimetry. J. Phys. Chem. C 118, 29533–29541 (2014).

    Article  Google Scholar 

  40. Glazier, S., Li, J., Louli, A., Allen, J. & Dahn, J. An analysis of artificial and natural graphite in lithium ion pouch cells using ultra-high precision coulometry, isothermal microcalorimetry, gas evolution, long term cycling and pressure measurements. J. Electrochem. Soc. 164, A3545–A3555 (2017).

    Article  Google Scholar 

  41. Glazier, S. et al. The effect of methyl acetate, ethylene sulfate, and carbonate blends on the parasitic heat flow of NMC532/graphite lithium ion pouch cells. J. Electrochem. Soc. 165, A867–A875 (2018).

    Article  Google Scholar 

  42. Aiken, C. et al. An apparatus for the study of in situ gas evolution in Li-ion pouch cells. J. Electrochem. Soc. 161, A1548–A1554 (2014).

    Article  Google Scholar 

  43. Zhu, Y., Li, Y., Bettge, M. & Abraham, D. P. Positive electrode passivation by LiDFOB electrolyte additive in high-capacity lithium-ion cells. J. Electrochem. Soc. 159, A2109–A2117 (2012).

    Article  Google Scholar 

Download references


J.-M.T. J.H. and L.A.B. acknowledge funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA and DIM RESPORE. J.B., S.T.B. and H.-Y.T. acknowledge funding from the General Research Fund Project (152087/18E) and the Hong Kong Polytechnic University (1-ZVGB). J.R.D. and E.R.L. thank the auspices of the NSERC/Tesla Canada IRC programme. E.R.L. thanks NSERC and The Nova Scotia Graduate Scholarship programme for scholarship support. We thank L. Htein from the Hong Kong Polytechnic University for his assistance in fabricating the microstructured optical fibres, and F. Rabuel and T. Lombard for preparing the NMC(111)/C 18650 cells. We thank TIAMAT for providing the NVPF/HC 18650 cells as well as Faurecia for supporting part of this work and IDIL for providing part of the FBG sensors. Finally, we gladly thank G. Assat, G. Yan, C. Cometto, B. Li and S. Mariyappan for extensive and valuable discussions and comments.

Author information

Authors and Affiliations



J.H., L.A.B. and J.-M.T. conceived the idea and designed the experiments with the help of D.A.D.C. for building the experimental set-up. J.H. performed the electrochemical, optical tests and the data analysis. J.B., S.T.B. and H.-Y.T. prepared the MOF-FBGs. E.R.L. and J.R.D. performed the isothermal calorimetry experiments. J.H. and C.D. performed the thermodynamics analysis with the help of B.M.G. Finally, J.-M.T., J.H. and L.A.B. wrote the paper, with contributions from all authors.

Corresponding author

Correspondence to Jean-Marie Tarascon.

Ethics declarations

Competing interests

A patent related to the work has been filed.

Additional information

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

Supplementary information

Supplementary Information

Supplementary Figs. 1–19, Notes 1 and 2, and references

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Huang, J., Albero Blanquer, L., Bonefacino, J. et al. Operando decoding of chemical and thermal events in commercial Na(Li)-ion cells via optical sensors. Nat Energy 5, 674–683 (2020).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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