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.

Highly efficient reversible protonic ceramic electrochemical cells for power generation and fuel production

An Author Correction to this article was published on 22 July 2020

This article has been updated


Reversible fuel cells based on both proton exchange membrane fuel cell and solid oxide fuel cell technologies have been proposed to address energy storage and conversion challenges and to provide versatile pathways for renewable fuels production. Both technologies suffer challenges associated with cost, durability, low round-trip efficiency and the need to separate H2O from the product fuel. Here, we present a reversible protonic ceramic electrochemical cell based on an yttrium and ytterbium co-doped barium cerate–zirconate electrolyte and a triple-conducting oxide air/steam (reversible) electrode that addresses many of these issues. Our reversible protonic ceramic electrochemical cell achieves a high Faradaic efficiency (90–98%) and can operate endothermically with a >97% overall electric-to-hydrogen energy conversion efficiency (based on the lower heating value of H2) at a current density of −1,000 mA cm−2. Even higher efficiencies are obtained for H2O electrolysis with co-fed CO2 to produce CO and CH4. We demonstrate a repeatable round-trip (electricity-to-hydrogen-to-electricity) efficiency of >75% and stable operation, with a degradation rate of <30 mV over 1,000 h.

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

Get just this article for as long as you need it


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

Fig. 1: Schematic of RePCECs and comparison with low-temperature proton exchange membrane electrolysis cells, intermediate-temperature solid oxide electrolysis cells and high-temperature solid oxide electrolysis cells.
Fig. 2: Model prediction of BZY20- and BCZYYb-based RePCEC performance.
Fig. 3: Experimental evaluation of BZY20- and BCZYYb-based RePCECs.
Fig. 4: Performance of a BCZYYb-based electrolyser (cell no. 14) under various steam concentrations at 600 °C.
Fig. 5: Electrochemical conversion of both CO2 and H2O in PCEC.
Fig. 6: Long-term stability testing of BCZYYb-based RePCECs in PCEC mode and under reversible cyclic operation.
Fig. 7: SEM images of cell no. 7 after 600 h operation.
Fig. 8: Long-term stability testing of BCZYYb-based RePCECs under reversible cyclic operation.

Data availability

The data that support the findings of this study are available from the corresponding authors on reasonable request. See Author contributions for specific datasets.

Change history


  1. Xu, L. et al. Plasma-engraved Co3O4 nanosheets with oxygen vacancies and high surface area for the oxygen evolution reaction. Angew. Chem. Int. Ed. 128, 5363–5367 (2016).

    Article  Google Scholar 

  2. Dresp, S. et al. An efficient bifunctional two-component catalyst for oxygen reduction and oxygen evolution in reversible fuel cells, electrolyzers and rechargeable air electrodes. Energy Environ. Sci. 9, 2020–2024 (2016).

    Article  Google Scholar 

  3. Park, S., Shao, Y., Liu, J. & Wang, Y. Oxygen electrocatalysts for water electrolyzers and reversible fuel cells: status and perspective. Energy Environ. Sci. 5, 9331 (2012).

    Article  Google Scholar 

  4. Liu, M. et al. Enhanced sulfur and coking tolerance of a mixed ion conductor for SOFCs: BaZr0.1Ce0.7Y0.2-xYbxO3-δ. Science 326, 126–129 (2009).

    Article  Google Scholar 

  5. Pellow, M. A., Emmott, C. J. M., Barnhart, C. J. & Benson, S. M. Hydrogen or batteries for grid storage? A net energy analysis. Energy Environ. Sci. 8, 1938–1952 (2015).

    Article  Google Scholar 

  6. Einar Vøllestad, R. Strandbakke, Beeaff, D. & Norby, T. Tubular proton ceramic steam electrolysers. In ICE2017 Conf. (2017).

  7. 2017 Annual Merit Review and Peer Evaluation (DOE Hydrogen and Fuel Cells Program, 2018);

  8. Chen, T. et al. High performance of intermediate temperature solid oxide electrolysis cells using Nd2NiO4+δ impregnated scandia stabilized zirconia oxygen electrode. J. Power Sources 276, 1–6 (2015).

    Article  Google Scholar 

  9. Liu, T. et al. Steam electrolysis in a solid oxide electrolysis cell fabricated by the phase-inversion tape casting method. Electrochem. Commun. 61, 106–109 (2015).

    Article  Google Scholar 

  10. Fang, Q., Blum, L. & Menzler, N. H. Performance and degradation of solid oxide electrolysis cells in stack. J. Electrochem. Soc. 162, F907–F912 (2015).

    Article  Google Scholar 

  11. Laguna-Bercero, M. A., Campana, R., Larrea, A., Kilner, J. A. & Orera, V. M. Steam electrolysis using a microtubular solid oxide fuel cell. J. Electrochem. Soc. 157, B852 (2010).

    Article  Google Scholar 

  12. Jensen, S. H., Larsen, P. H. & Mogensen, M. Hydrogen and synthetic fuel production from renewable energy sources. Int. J. Hydrogen Energy 32, 3253–3257 (2007).

    Article  Google Scholar 

  13. Wendel, C. H., Gao, Z., Barnett, S. A. & Braun, R. J. Modeling and experimental performance of an intermediate temperature reversible solid oxide cell for high-efficiency, distributed-scale electrical energy storage. J. Power Sources 283, 329–342 (2015).

    Article  Google Scholar 

  14. Jensen, S. H. et al. Large-scale electricity storage utilizing reversible solid oxide cells combined with underground storage of CO2 and CH4. Energy Environ. Sci. 8, 2471–2479 (2015).

    Article  Google Scholar 

  15. Gao, Z. et al. Tape casting of high-performance low-temperature solid oxide cells with thin La0.8Sr0.2Ga0.8Mg0.2O3−δ electrolytes and impregnated nano anodes. ACS Appl. Mater. Interfaces 9, 7115–7124 (2017).

    Article  Google Scholar 

  16. Zhang, S.-L. et al. Cobalt-substituted SrTi0.3Fe0.7O3−δ: a stable high-performance oxygen electrode material for intermediate-temperature solid oxide electrochemical cells. Energy Environ. Sci. 11, 1870–1879 (2018).

    Article  Google Scholar 

  17. Ishihara, T., Jirathiwathanakul, N. & Zhong, H. Intermediate temperature solid oxide electrolysis cell using LaGaO3 based perovskite electrolyte. Energy Environ. Sci. 3, 665–672 (2010).

    Article  Google Scholar 

  18. Morejudo, S. H. et al. Direct conversion of methane to aromatics in a catalytic co-ionic membrane reactor. Science 353, 563–566 (2016).

    Article  Google Scholar 

  19. Malerød-Fjeld, H. et al. Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss. Nat. Energy 2, 923–931 (2017).

    Article  Google Scholar 

  20. Gan, Y. et al. Composite oxygen electrode based on LSCM for steam electrolysis in a proton conducting solid oxide electrolyzer. J. Electrochem. Soc. 159, F763–F767 (2012).

    Article  Google Scholar 

  21. Li, S., Yan, R., Wu, G., Xie, K. & Cheng, J. Composite oxygen electrode LSM-BCZYZ impregnated with Co3O4 nanoparticles for steam electrolysis in a proton-conducting solid oxide electrolyzer. Int. J. Hydrogen Energy 38, 14943–14951 (2013).

    Article  Google Scholar 

  22. Li, H., Chen, X., Chen, S., Wu, Y. & Xie, K. Composite manganate oxygen electrode enhanced with iron oxide nanocatalyst for high temperature steam electrolysis in a proton-conducting solid oxide electrolyzer. Int. J. Hydrogen Energy 40, 7920–7931 (2015).

    Article  Google Scholar 

  23. Li, S. & Xie, K. Composite oxygen electrode based on LSCF and BSCF for steam electrolysis in a proton-conducting solid oxide electrolyzer. J. Electrochem. Soc. 160, F224–F233 (2013).

    Article  Google Scholar 

  24. Gan, L. et al. A scandium-doped manganate anode for a proton-conducting solid oxide steam electrolyzer. RSC Adv. 6, 641–647 (2016).

    Article  Google Scholar 

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

    Article  Google Scholar 

  26. Dippon, M., Babiniec, S. M., Ding, H., Ricote, S. & Sullivan, N. P. Exploring electronic conduction through BaCexZr0.9-xY0.1O3-d proton-conducting ceramics. Solid State Ion. 286, 117–121 (2016).

    Article  Google Scholar 

  27. Babiniec, S. M., Ricote, S. & Sullivan, N. P. Characterization of ionic transport through BaCe0.2 Zr0.7Y0.1O3-δ membranes in galvanic and electrolytic operation. Int. J. Hydrogen Energy 40, 9278–9286 (2015).

    Article  Google Scholar 

  28. Zhu, H. & Kee, R. J. Membrane polarization in mixed-conducting ceramic fuel cells and electrolyzers. Int. J. Hydrogen Energy 41, 2931–2943 (2016).

    Article  Google Scholar 

  29. Ricote, S., Bonanos, N. & Caboche, G. Water vapour solubility and conductivity study of the proton conductor BaCe0.9-xZrxY0.1O13-δ. Solid State Ion. 180, 990–997 (2009).

    Article  Google Scholar 

  30. Zhu, H. et al. Defect incorporation and transport within dense BaZr0.8Y0.2O3−δ (BZY20) proton-conducting membranes. J. Electrochem. Soc. 165, F581–F588 (2018).

    Article  Google Scholar 

  31. Nomura, K. & Kageyama, H. Transport properties of Ba(Zr0.8Y0.2)O3-δ perovskite. Solid State Ion. 178, 661–665 (2007).

    Article  Google Scholar 

  32. Sumikawa, T. et al. Physicochemical properties of proton-conductive BaZr0.1Ce0.7Y0.1Yb0.1O3−δ solid electrolyte in terms of electrochemical performance of solid oxide fuel cells. Int. J. Hydrogen Energy 41, 17539–17547 (2016).

    Article  Google Scholar 

  33. Kattel, S., Liu, P. & Chen, J. G. Tuning selectivity of CO2 hydrogenation reactions at the metal/oxide interface. J. Am. Chem. Soc. 139, 9739–9754 (2017).

    Article  Google Scholar 

  34. Kee, R. J. et al. Modeling the steady-state and transient response of polarized and non-polarized proton-conducting doped-perovskite membranes. J. Electrochem. Soc. 160, F290–F300 (2013).

    Article  Google Scholar 

  35. Vøllestad, E., Zhu, H. & Kee, R. J. Interpretation of defect and gas-phase fluxes through mixed-conducting ceramics using Nernst–Planck–Poisson and integral formulations. J. Electrochem. Soc. 161, 114–124 (2014).

    Article  Google Scholar 

  36. Zhu, H. & Kee, R. J. Modeling protonic-ceramic fuel cells with porous composite electrodes in a button-cell configuration. J. Electrochem. Soc. 164, F1400–F1411 (2017).

    Article  Google Scholar 

  37. Zhu, H., Ricote, S., Coors, W. G. & Kee, R. J. Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defect conducting ceramics. Faraday Discuss. 182, 49–74 (2015).

    Article  Google Scholar 

  38. O’Hayre, R., Cha, S. W., Prinz, F. B. & Colella, W. Fuel Cell Fundamentals (John Wiley & Sons, 2016).

  39. Frade, J. R. Theoretical behaviour of concentration cells based on ABO3 perovskite materials with protonic and oxygen ion conduction. Solid State Ion. 78, 87–97 (1995).

    Article  Google Scholar 

Download references


This work was supported by the Advanced Research Projects Agency–Energy (ARPA-E) through the REFUEL (award DE-AR0000808) and REBELS programmes (award DE-AR0000493). Additional support was provided by the Army Research Office under grant number W911NF-17-1-0051, the Office of Naval Research via grant N00014-16-1-2780, the National Science Foundation via grant DMR156375, the Colorado School of Mines Foundation via the Angel Research Fund and the Colorado Office of Economic Development and International Trade (COEDIT) under their Advanced Industries Proof-of-Concept Grant programme. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of ARPA-E, the Department of Energy, the Army Research Office or the US Government.

Author information

Authors and Affiliations



C.D. and R.O. developed the intellectual concept, designed the experiments, analysed the data and led the manuscript writing. H.Z. and R.K. developed the PCFC and PCEC model comparisons and contributed to the discussion and analysis. D.J. performed the transmission electron microscopy. N.S., L.Z. and L.B. provided suggestions on the experiments, data interpretation and manuscript refinement.

Corresponding authors

Correspondence to Chuancheng Duan or Ryan O’Hayre.

Ethics declarations

Competing interests

The authors declare no competing interests.

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 Figures 1–16, Supplementary Note 1, Supplementary Tables 1–5, Supplementary references.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Duan, C., Kee, R., Zhu, H. et al. Highly efficient reversible protonic ceramic electrochemical cells for power generation and fuel production. Nat Energy 4, 230–240 (2019).

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