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Revitalizing interface in protonic ceramic cells by acid etch



Protonic ceramic electrochemical cells hold promise for operation below 600 °C (refs. 1,2). Although the high proton conductivity of the bulk electrolyte has been demonstrated, it cannot be fully used in electrochemical full cells because of unknown causes3. Here we show that these problems arise from poor contacts between the low-temperature processed oxygen electrode–electrolyte interface. We demonstrate that a simple acid treatment can effectively rejuvenate the high-temperature annealed electrolyte surface, resulting in reactive bonding between the oxygen electrode and the electrolyte and improved electrochemical performance and stability. This enables exceptional protonic ceramic fuel-cell performance down to 350 °C, with peak power densities of 1.6 W cm−2 at 600 °C, 650 mW cm−2 at 450 °C and 300 mW cm−2 at 350 °C, as well as stable electrolysis operations with current densities above 3.9 A cm−2 at 1.4 V and 600 °C. Our work highlights the critical role of interfacial engineering in ceramic electrochemical devices and offers new understanding and practices for sustainable energy infrastructures.

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Fig. 1: Rejuvenated surface improves oxygen electrode–electrolyte interfacial strength.
Fig. 2: Reactive sintering at oxygen electrode–electrolyte interface improves interfacial bonding.
Fig. 3: Correlation between simultaneously lowered ohmic and polarization resistance.
Fig. 4: Boosted electrochemical performance with modified oxygen electrode–electrolyte interface.

Data availability

Data supporting the findings in the present work are available in the manuscript or Supplementary Information. Additional data are available from the corresponding authors upon reasonable request.


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This work is supported by the US Department of Energy (DoE), Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under DoE Idaho Operations Office under contract no. DE-AC07-05ID14517. Y.D. and J.L. acknowledge support by the DoE, Basic Energy Sciences, under award number DE-SC0002633 (Chemomechanics of Far-From-Equilibrium Interfaces). C.J. and M.Z. thank the subcontracts from Idaho National Laboratory and M.Z. also acknowledges funding support from National Science Foundation (no. OIA-2119688).

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Authors and Affiliations



W.B., W.W., Y.D., J.L. and D.D. conceived the project. W.B. and W.W. fabricated the cells and conducted electrochemical measurements. Y.D. conducted the theoretical analysis. Y.D. and W.B. analysed the data. B.W. contributed to STEM characterizations. W.T. contributed to cell fabrications and SEM characterizations. M.Z. contributed to AFM characterizations. C.J. contributed to peeling tests. H.D. contributed to the development of the oxygen electrode. W.F. contributed to XPS measurements. W.B., W.W., Y.D., J.L. and D.D. wrote the paper. All authors discussed and contributed to writing.

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Correspondence to Wei Wu, Yanhao Dong, Ju Li or Dong Ding.

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Nature thanks Truls Norby and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Figs. 1–28 and Supplementary Tables 1–9.

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Bian, W., Wu, W., Wang, B. et al. Revitalizing interface in protonic ceramic cells by acid etch. Nature 604, 479–485 (2022).

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