With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H−) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm−1 at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on.
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Schlapbach, L. & Zuttel, A. Hydrogen-storage materials for mobile applications. Nature 414, 353–358 (2001).
Chen, P., Xiong, Z. T., Luo, J. Z., Lin, J. Y. & Tan, K. L. Interaction of hydrogen with metal nitrides and imides. Nature 420, 302–304 (2002).
Zuttel, A. et al. LiBH4 a new hydrogen storage material. J. Power Sources 118, 1–7 (2003).
Blanchard, D., Brinks, H. W., Hauback, B. C. & Norby, P. Desorption of LiAlH4 with Ti- and V-based additives. Mater. Sci. Eng. 108, 54–59 (2004).
Peterson, D. T. & Indig, M. The barium–barium hydride system. J. Am. Chem. Soc. 82, 5645–5646 (1960).
Verbraeken, M. C., Suard, E. & Irvine, J. T. S. Structural and electrical properties of calcium and strontium hydrides. J. Mater. Chem. 19, 2766–2770 (2009).
Bronger, W., Scha, C. C. & Muller, P. Crystal-structure of barium hydride, determined by neutron-diffraction experiments on BaD2 . Z. Anorg. Allg. Chem. 545, 69–74 (1987).
Ting, V. P., Henry, P. F., Kohlmann, H., Wilson, C. C. & Weller, M. T. Structural isotope effects in metal hydrides and deuterides. Phys. Chem. Chem. Phys. 12, 2083–2088 (2010).
Dorfman, S. M. et al. Phase transitions and equations of state of alkaline earth fluorides CaF2, SrF2, and BaF2 to Mbar pressures. Phys. Rev. B 81, 174121 (2010).
Wang, J. S. et al. Structural phase transitions of SrF2 at high pressure. J. Solid State Chem. 186, 231–234 (2012).
Tse, J. S. et al. Structural phase transition in CaH2 at high pressures. Phys. Rev. B 75, 134108 (2007).
Smith, J. S., Desgreniers, S., Klug, D. D. & Tse, J. S. High-density strontium hydride: An experimental and theoretical study. Solid State Commun. 149, 830–834 (2009).
Smith, J. S., Desgreniers, S., Tse, J. S. & Klug, D. D. High-pressure phase transition observed in barium hydride. J. Appl. Phys. 102, 043520 (2007).
Hull, S., Keen, D. A., Sivia, D. S. & Berastegui, P. Crystal structures and ionic conductivities of ternary derivatives of the silver and copper monohalides - I. Superionic phases of stoichiometry MA4I5: RbAg4I5, KAg4I5, and KCu4I5 . J. Solid State Chem. 165, 363–371 (2002).
Gorelov, V. P. & Pal’guev, S. F. Conductivity in CaH2–LiH and CaH2–CaF2 systems. Elektrokhimiya 28, 1294–1296 (1992).
Gibson, I. R. & Irvine, J. T. S. Study of the order–disorder transition in yttria-stabilised zirconia by neutron diffraction. J. Mater. Chem. 6, 895–898 (1996).
Steele, B. C. H. in High Conductivity Solid Ionic Conductors (ed Takahashi, T.) 402–446 (World Scientific Publishing, 1989).
Steele, B. C. H. Appraisal of Ce1−yGdyO2−y/2 electrolytes for IT-SOFC operation at 500 °C. Solid State Ion. 129, 95–110 (2000).
Chen, F. L., Sorensen, O. T., Meng, G. Y. & Peng, D. K. Preparation of Nd-doped BaCeO3 proton-conducting ceramic and its electrical properties in different atmospheres. J. Eur. Ceram. Soc. 18, 1389–1395 (1998).
Omar, S., Wachsman, E. D. & Nino, J. C. Higher conductivity Sm3+ and Nd3+ co-doped ceria-based electrolyte materials. Solid State Ion. 178, 1890–1897 (2008).
Norby, T. Solid-state protonic conductors: Principles, properties, progress and prospects. Solid State Ion. 125, 1–11 (1999).
Hayward, M. A. et al. The hydride anion in an extended transition metal oxide array: LaSrCoO3H0.7 . Science 295, 1882–1884 (2002).
Norby, T., Wideroe, M., Glockner, R. & Larring, Y. Hydrogen in oxides. Dalton Trans. 19, 3012–3018 (2004).
Boukamp, B. A. A linear Kronig–Kramers transform test for immittance data validation. J. Electrochem. Soc. 142, 1885–1894 (1995).
We thank EPSRC for support through a Platform Grant, the Royal Society for a Wolfson Merit award and Institut Laue-Langevin for provision of neutron beam time.
The authors declare no competing financial interests.
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Verbraeken, M., Cheung, C., Suard, E. et al. High H− ionic conductivity in barium hydride. Nature Mater 14, 95–100 (2015). https://doi.org/10.1038/nmat4136
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