Abstract
Protonic ceramic electrochemical cells (PCECs) can be employed for power generation and sustainable hydrogen production. Lowering the PCEC operating temperature can facilitate its scale-up and commercialization. However, achieving high energy efficiency and long-term durability at low operating temperatures is a long-standing challenge. Here, we report a simple and scalable approach for fabricating ultrathin, chemically homogeneous, and robust proton-conducting electrolytes and demonstrate an in situ formed composite positive electrode, Ba0.62Sr0.38CoO3−δ–Pr1.44Ba0.11Sr0.45Co1.32Fe0.68O6−δ, which significantly reduces ohmic resistance, positive electrode–electrolyte contact resistance and electrode polarization resistance. The PCECs attain high power densities in fuel-cell mode (~0.75 W cm−2 at 450 °C and ~0.10 W cm−2 at 275 °C) and exceptional current densities in steam electrolysis mode (−1.28 A cm−2 at 1.4 V and 450 °C). At 600 °C, the PCECs achieve a power density of ~2 W cm−2. Additionally, we demonstrate the direct utilization of methane and ammonia for power generation at <450 °C. Our PCECs are also stable for power generation and hydrogen production at 400 °C.
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Data availability
The data supporting the findings of this study are available within the Article and its Supplementary Information files.
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Acknowledgements
This work was financially supported by the Nissan Motor Co., Ltd (A22-0455-001, C.D.), Department of Energy grants (DE-FE0032005, DE-SC0021505, DE-FE0032235 and DE-FE0032300, C.D.) and a National Aeronautics and Space Administration grant (80NSSC21C0220, C.D.). Some of the work was performed in following core facility, which is a part of Colorado School of Mines’ Shared Instrumentation Facility (Electron Microscopy: RRID:SCR_022048).
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Conceptualization: C.D., F.L. Methodology: C.D., F.L., D.D., H.D., B.L. Investigation: C.D., F.L., H.D., D.D., P. Kumar, M.H.A.J., C.G., Y.F., N.D., T.O., M.U., P. Kazempoor, L.F., D.C., B.L. Visualization: C.D., F.L. Funding acquisition: C.D. Project administration: C.D. Supervision: C.D. Writing—original draft: C.D., F.L. Writing—review & editing: C.D., F.L., H.D., D.D., P. Kumar, M.H.A.J., C.G., Y.F., N.D., T.O., M.U., P. Kazempoor, L.F., D.C., B.L.
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Part of this work is financially supported by the Nissan Motor Co., Ltd (A22-0455-001). The funder participates in the decision to publish and preparation of the manuscript. Co-authors M.H.A.J., C.G., Y.F. and N.D. are employed at Nissan Technical Centre North America (NTCNA), Farmington Hills, MI, USA. Co-authors T.O. and M.U. are employed at Nissan Research Center, Nissan Motor Company Limited, Yokosuka, Japan.
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Supplementary Notes 1–4, Figs. 1–41, Tables 1–8 and references.
Supplementary Data 1
Atomic coordinates (POSCARs) of bulk structures, structures with oxygen vacancies, and initial and final states of oxygen diffusion calculations OF BSC, PBSCF-1 and PBSCF-2.
Supplementary Video 1
A demonstration of green hydrogen production at 400 °C.
Supplementary Video 2
Button PCEC electrolyte ultrasonic spray coating.
Supplementary Video 3
Large-area PCEC electrolyte ultrasonic spray coating.
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Liu, F., Deng, H., Diercks, D. et al. Lowering the operating temperature of protonic ceramic electrochemical cells to <450 °C. Nat Energy 8, 1145–1157 (2023). https://doi.org/10.1038/s41560-023-01350-4
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DOI: https://doi.org/10.1038/s41560-023-01350-4