Article | Published:

Exceptional power density and stability at intermediate temperatures in protonic ceramic fuel cells

Nature Energyvolume 3pages202210 (2018) | Download Citation


Over the past several years, important strides have been made in demonstrating protonic ceramic fuel cells (PCFCs). Such fuel cells offer the potential of environmentally sustainable and cost-effective electric power generation. However, their power outputs have lagged behind predictions based on their high electrolyte conductivities. Here we overcome PCFC performance and stability challenges by employing a high-activity cathode, PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF), in combination with a chemically stable electrolyte, BaZr0.4Ce0.4Y0.1Yb0.1O3 (BZCYYb4411). We deposit a thin dense interlayer film of the cathode material onto the electrolyte surface to mitigate contact resistance, an approach which is made possible by the proton permeability of PBSCF. The peak power densities of the resulting fuel cells exceed 500 mW cm−2 at 500 °C, while also offering exceptional, long-term stability under CO2.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Additional information

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


  1. 1.

    Fabbri, E., Pergolesi, D. & Traversa, E. Materials challenges toward proton-conducting oxide fuel cells: a critical review. Chem. Soc. Rev. 39, 4355–4369 (2010).

  2. 2.

    Nguyen, N. T. Q. & Yoon, H. H. Preparation and evaluation of BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) electrolyte and BZCYYb-based solid oxide fuel cells. J. Power Sources 231, 213–218 (2013).

  3. 3.

    Duan, C. et al. Readily processed protonic ceramic fuel cells with high performance at low temperatures. Science 349, 1321–1326 (2015).

  4. 4.

    Nien, S. H., Hsu, C. S., Chang, C. L. & Hwang, B. H. Preparation of BaZr0.1Ce0.7Y0.2O3–δ based solid oxide fuel cells with anode functional layers by tape casting. Fuel Cells 11, 178–183 (2011).

  5. 5.

    Bae, K. et al. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells. Nat. Commun. 8, 14553 (2017).

  6. 6.

    Yoo, S., Choi, S., Kim, J., Shin, J. & Kim, G. Investigation of layered perovskite type NdBa1−xSr x Co 2O5+δ (x= 0, 0.25, 0.5, 0.75, and 1.0) cathodes for intermediate-temperature solid oxide fuel cells. Electrochim. Acta 100, 44–50 (2013).

  7. 7.

    Liu, Q. L., Khor, K. A. & Chan, S. H. High-performance low-temperature solid oxide fuel cell with novel BSCF cathode. J. Power Sources 161, 123–128 (2006).

  8. 8.

    Shao, Z. & Haile, S. M. A high-performance cathode for the next generation of solid-oxide fuel cells. Nature 431, 170–173 (2004).

  9. 9.

    Choi, S. et al. Highly efficient and robust cathode materials for low-temperature solid oxide fuel cells: PrBa0.5Sr0.5Co2−xFe x O5+δ. Sci. Rep. 3, 2426 (2013).

  10. 10.

    Fabbri, E., Markus, I., Bi, L., Pergolesi, D. & Traversa, E. Tailoring mixed proton-electronic conductivity of BaZrO3 by Y and Pr co-doping for cathode application in protonic SOFCs. Solid State Ion. 202, 30–35 (2011).

  11. 11.

    Wang, Z. et al. A mixed-conducting BaPr0.8In0.2O3−δ cathode for proton-conducting solid oxide fuel cells. Electrochem. Commun. 27, 19–21 (2013).

  12. 12.

    Han, D., Okumura, Y., Nose, Y. & Uda, T. Synthesis of La1−xSr x Sc1−yFe y O3−δ (LSSF) and measurement of water content in LSSF, LSCF and LSC hydrated in wet artificial air at 300°C. Solid State Ion. 181, 1601–1606 (2010).

  13. 13.

    Grimaud, A. et al. Hydration and transport properties of the Pr2-xSr x NiO4+δ compounds as H+-SOFC cathodes. J. Mater. Chem. 22, 16017–16025 (2012).

  14. 14.

    Grimaud, A. et al. Hydration properties and rate determining steps of the oxygen reduction reaction of perovskite-related oxides as H+-SOFC cathodes. J. Electrochem. Soc. 159, B683–B694 (2012).

  15. 15.

    Strandbakke, R. et al. Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells. Solid State Ion. 278, 120–132 (2015).

  16. 16.

    Fabbri, E., D'Epifanio, A., Di Bartolomeo, E., Licoccia, S. & Traversa, E. Tailoring the chemical stability of Ba(Ce0.8−xZr x )Y0.2O3−δ protonic conductors for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs). Solid State Ion. 179, 558–564 (2008).

  17. 17.

    Yang, L. et al. Enhanced sulfur and coking tolerance of a mixed ion conductor for SOFCs: BaZr0. 1Ce0. 7Y0.2–xYb x O3–δ. Science 326, 126–129 (2009).

  18. 18.

    Haile, S. M., Staneff, G. & Ryu, K. H. Non-stoichiometry, grain boundary transport and chemical stability of proton conducting perovskites. J. Mater. Sci. 36, 1149–1160 (2001).

  19. 19.

    Takayama-Muromachi, E. & Navrotsky, A. Energetics of compounds (A2+B4+O3) with the perovskite structure. J. Solid State Chem. 72, 244–256 (1988).

  20. 20.

    Ryu, K. H. & Haile, S. M. Chemical stability and proton conductivity of doped BaCeO3–BaZrO3 solid solutions. Solid State Ion. 125, 355–367 (1999).

  21. 21.

    Yamazaki, Y., Hernandez-Sanchez, R. & Haile, S. M. High total proton conductivity in large-grained yttrium-doped barium zirconate. Chem. Mater. 21, 2755–2762 (2009).

  22. 22.

    Bozza, F., Arroyo, Y. & Graule, T. Flame spray synthesis of BaZr0.8Y0.2O3–δ electrolyte nanopowders for intermediate temperature proton conducting fuel cells. Fuel Cells 15, 588–594 (2015).

  23. 23.

    Ling, Y., Yu, J., Zhang, X., Zhao, L. & Liu, X. A cobalt-free Sm0.5Sr0.5Fe0.8Cu0.2O3−δ–Ce0.8Sm0.2O2−δ composite cathode for proton-conducting solid oxide fuel cells. J. Power Sources 196, 2631–2634 (2011).

  24. 24.

    Kim, J. et al. Triple‐conducting layered perovskites as cathode materials for proton‐conducting solid oxide fuel cells. ChemSusChem 7, 2811–2815 (2014).

  25. 25.

    Choi, S., Shin, J. & Kim, G. The electrochemical and thermodynamic characterization of PrBaCo2−x Fe x O5+δ (x= 0, 0.5, 1) infiltrated into yttria-stabilized zirconia scaffold as cathodes for solid oxide fuel cells. J. Power Sources 201, 10–17 (2012).

  26. 26.

    Kim, G. et al. Rapid oxygen ion diffusion and surface exchange kinetics in PrBaCo2O5+x with a perovskite related structure and ordered A cations. J. Mater. Chem. 17, 2500–2505 (2007).

  27. 27.

    Kim, J. H., Cassidy, M., Irvine, J. T. & Bae, J. Electrochemical investigation of composite cathodes with SmBa0.5Sr0.5Co2O5+δ cathodes for intermediate temperature-operating solid oxide fuel cell. Chem. Mater. 22, 883–892 (2009).

  28. 28.

    Jun, A. et al. Correlation between fast oxygen kinetics and enhanced performance in Fe doped layered perovskite cathodes for solid oxide fuel cells. J. Mater. Chem. A 3, 15082–15090 (2015).

  29. 29.

    Kim, J.-H. & Manthiram, A. Layered LnBaCo2O5+δ perovskite cathodes for solid oxide fuel cells: an overview and perspective. J. Mater. Chem. A 3, 24195–24210 (2015).

  30. 30.

    Jeong, D. et al. Structural, electrical, and electrochemical characteristics of LnBa0.5Sr0.5Co1.5Fe0.5O5+δ (Ln=Pr, Sm, Gd) as cathode materials in intermediate-temperature solid oxide fuel cells. Energy Technol. 5, 1337–1343 (2017).

  31. 31.

    Kim, J.-H., Prado, F. & Manthiram, A. Characterization of GdBa1−xSr x Co2O5+δ (0x1.0) double perovskites as cathodes for solid oxide fuel cells. J. Electrochem. Soc. 155, B1023–B1028 (2008).

  32. 32.

    Burriel, Mn et al. Anisotropic oxygen ion diffusion in layered PrBaCo2O5+δ. Chem. Mater. 24, 613–621 (2012).

  33. 33.

    Hashimoto, D., Han, D. & Uda, T. Dependence of lattice constant of Ba, Co-contained perovskite oxides on atmosphere, and measurements of water content. Solid State Ion. 262, 687–690 (2014).

  34. 34.

    Yamazaki, Y., Babilo, P. & Haile, S. M. Defect chemistry of yttrium-doped barium zirconate: a thermodynamic analysis of water uptake. Chem. Mater. 20, 6352–6357 (2008).

  35. 35.

    Yamazaki, Y., Yang, C.-K. & Haile, S. M. Unraveling the defect chemistry and proton uptake of yttrium-doped barium zirconate. Scr. Mater. 65, 102–107 (2011).

  36. 36.

    Poetzsch, D., Merkle, R. & Maier, J. Proton uptake in the H+-SOFC cathode material Ba0.5Sr0.5Fe0.8 Zn0.2O3−δ: transition from hydration to hydrogenation with increasing oxygen partial pressure. Faraday Discuss. 182, 129–143 (2015).

  37. 37.

    Zohourian, R., Merkle, R. & Maier, J. Proton uptake into the protonic cathode material BaCo0.4Fe0.4 Zr0.2O3-δ and comparison to protonic electrolyte materials. Solid State Ion. 299, 64–69 (2017).

  38. 38.

    Hildenbrand, N., Boukamp, B. A., Nammensma, P. & Blank, D. H. Improved cathode/electrolyte interface of SOFC. Solid State Ion. 192, 12–15 (2011).

  39. 39.

    Usiskin, R. E., Maruyama, S., Kucharczyk, C. J., Takeuchi, I. & Haile, S. M. Probing the reaction pathway in (La0.8Sr0.2)0.95MnO3+δ using libraries of thin film microelectrodes. J. Mater. Chem. A 3, 19330–19345 (2015).

  40. 40.

    Newman, J. Resistance for flow of current to a disk. J. Electrochem. Soc. 113, 501–502 (1966).

  41. 41.

    Pechini, M. P. Method of preparing lead and alkaline earth titanates and niobates and coating method using the same form a capacitor. US Patent 3,330,697 (1967).

  42. 42.

    Babilo, P., Uda, T. & Haile, S. M. Processing of yttrium-doped barium zirconate for high proton conductivity. J. Mater. Res. 22, 1322–1330 (2007).

Download references


This research was funded in part by the US Department of Energy, through ARPA-e Contract DE-AR0000498, via subcontract from United Technologies Research Center, and by the National Science Foundation, DMR-1505103. Selected facilities used were supported by the National Science Foundation via Northwestern University’s MRSEC, DMR-1121262.

Author information


  1. Materials Science and Engineering, Northwestern University, Evanston, IL, USA

    • Sihyuk Choi
    • , Chris J. Kucharczyk
    • , Ho-Il Ji
    •  & Sossina M. Haile
  2. Applied Physics & Materials Science, California Institute of Technology, Pasadena, CA, USA

    • Chris J. Kucharczyk
    •  & Ho-Il Ji
  3. Materials Science and Engineering, University of Maryland, College Park, MD, USA

    • Yangang Liang
    • , Xiaohang Zhang
    •  & Ichiro Takeuchi


  1. Search for Sihyuk Choi in:

  2. Search for Chris J. Kucharczyk in:

  3. Search for Yangang Liang in:

  4. Search for Xiaohang Zhang in:

  5. Search for Ichiro Takeuchi in:

  6. Search for Ho-Il Ji in:

  7. Search for Sossina M. Haile in:


S.M.H led the development of the concept, guided the experimental design, and supervised the research. S.C. developed the materials, fabricated the cells, and performed the following experiments and analyses: conductivity, thermogravimetry, fuel cell polarization, and impedance spectroscopy. Y.L. and X.Z. prepared and characterized PLD microdot electrodes, on which C.J.K. performed electrochemical measurements. I.T. supervised PLD film growth and characterization. H.-I. J. provided critical suggestions for experimental and analytical methods. S.M.H. and S.C. wrote the paper with contributions from all authors.

Corresponding author

Correspondence to Sossina M. Haile.

Supplementary information

  1. Supplementary Information

    Supplementary Figures 1–15, Supplementary Table 1 and Supplementary References

About this article

Publication history





Further reading