Skip to main content

Thank you for visiting nature.com. 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.

  • Review Article
  • Published:

Water uptake of solids and its impact on ion transport

Nature Materials volume 24, pages 821–834 (2025)Cite this article

Subjects

Abstract

The interaction modes of water with (polar) solids are manifold, comprising surface adsorption and incorporation into the bulk, both in molecular and in dissociated form. This Review discusses these processes and the respective pronounced effects on the ionic transport properties. The concentration as well as the mobility of ionic carriers can vary by orders of magnitude depending on the water content on or within a solid. Selected materials examples, which are relevant for electrochemical devices (for example, low- and intermediate-temperature fuel cells) or which are of fundamental interest (such as molecular water acting as dopant in a lithium halide), are treated in more detail. Interrelations between hydration and electronic defects are also briefly touched upon.

Access through your institution
Buy or subscribe

This is a preview of subscription content, access via your institution

Access options

Access through your institution

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

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

Fig. 1: The manifold properties of water, its amphoteric character analogous to defect formation in solids and its interaction with ionic solids.
Fig. 2: Characteristic interaction scenarios of water with an oxide (with low and high adsorbed molecular water coverage).
Fig. 3: Water incorporation into redox-inactive and redox-active oxides.
Fig. 4: Molecular uptake of water (or other small solvents) into ion exchange membranes, and relation to ‘soggy sand’ electrolytes.
Fig. 5: Interaction of water with LiSCN encompassing molecular substitution (doping), reaction (hydrate phase formation) and addition (formation of solvation shell).
Fig. 6: Characteristic features of surface proton conductivity on porous ionic oxides.
Fig. 7: Biological ion channels creating selectivity by tuning the hydration and coordination sphere.

Similar content being viewed by others

References

  1. Coulson, C. A. Valence (Oxford Univ. Press, 1961).

  2. Marx, D., Tuckerman, M. E., Hutter, J. & Parrinello, M. The nature of the hydrated excess proton in water. Nature 397, 601–604 (1999).

    Article  CAS  Google Scholar 

  3. Agmon, N. et al. Protons and hydroxide ions in aqueous systems. Chem. Rev. 116, 7642–7672 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Munoz-Santiburcio, D. & Marx, D. Confinement-controlled aqueous chemistry within nanometric slit pores. Chem. Rev. 121, 6293–6320 (2021).

    Article  CAS  PubMed  Google Scholar 

  5. Maier, J. Nanoionics: ionic charge carriers in small systems. Phys. Chem. Chem. Phys. 11, 3011–3022 (2009).

    Article  CAS  PubMed  Google Scholar 

  6. Bunker, B. C. & Casey, W. H. The Aqueous Chemistry of Oxides (Oxford Univ. Press, 2016).

  7. Maier, J. Acid–base centers and acid–base scales in ionic solids. Chem. Eur. J. 7, 4762–4770 (2001).

    Article  CAS  PubMed  Google Scholar 

  8. Marx, D. Proton transfer 200 years after von Grotthuss: insights from ab initio simulations. ChemPhysChem 7, 1848–1870 (2006).

    Article  CAS  PubMed  Google Scholar 

  9. Hainovsky, N. & Maier, J. Simple phenomenological approach to premelting and sublattice melting in Frenkel disordered ionic crystals. Phys. Rev. B 51, 15789–15797 (1995).

    Article  CAS  Google Scholar 

  10. Maier, J. & Munch, W. Thermal destiny of an ionic crystal. Z. Anorg. Allg. Chem. 626, 264–269 (2000).

    Article  CAS  Google Scholar 

  11. Cavazzoni, C. et al. Superionic and metallic states of water and ammonia at giant planet conditions. Science 283, 44–46 (1999).

    Article  CAS  PubMed  Google Scholar 

  12. Björneholm, O. et al. Water at interfaces. Chem. Rev. 116, 7698–7726 (2016).

    Article  PubMed  Google Scholar 

  13. Takada, K. et al. Superconductivity in two-dimensional CoO2 layers. Nature 422, 53–55 (2003).

    Article  CAS  PubMed  Google Scholar 

  14. Spaeth, M., Kreuer, K. D. & Maier, J. Giant Haven ratio for proton transport in sodium hydroxide. J. Solid State Chem. 148, 169–177 (1999).

    Article  CAS  Google Scholar 

  15. Joos, M. et al. Lithium ion transport in water-containing Li(SCN) over a wide compositional range: from water doping to hydration. Solid State Ion. 394, 116130 (2023).

    Article  CAS  Google Scholar 

  16. Armstrong, R. D. & Landles, K. Lithium ion conducting solids for ambient applications. J. Appl. Electrochem. 12, 533–535 (1982).

    Article  CAS  Google Scholar 

  17. Nakamura, O. & Goodenough, J. B. Conductivity enhancement of lithium bromide monohydrate by Al2O3 particles. Solid State Ion. 7, 119–123 (1982).

    Article  CAS  Google Scholar 

  18. Hartwig, P. & Weppner, W. Ionic conductivities of lithium-halide-based quaternary compounds. Solid State Ion. 3/4, 249–254 (1981).

    Article  Google Scholar 

  19. Eigen, M. & DeMaeyer, L. Self-dissociation and protonic charge transport in water and ice. Proc. R. Soc. A 247, 505–533 (1958).

    CAS  Google Scholar 

  20. Kreuer, K. D., Rabenau, A. & Weppner, W. Vehicle mechanism, a new model for the interpretation of the conductivity of fast proton conductors. Angew. Chem. Int. Ed. 21, 208–209 (1982).

    Article  Google Scholar 

  21. Maier, J. Concentration polarization of salt-containing liquid electrolytes. Adv. Funct. Mater. 21, 1448–1455 (2011).

    Article  CAS  Google Scholar 

  22. Li, X. et al. Water-mediated synthesis of a superionic halide solid electrolyte. Angew. Chem. Int. Ed. 58, 16427–16432 (2019).

    Article  CAS  Google Scholar 

  23. Kreuer, K. D. Proton-conducting oxides. Annu. Rev. Mater. Res. 33, 333–359 (2003).

    Article  CAS  Google Scholar 

  24. Sun, X. et al. Surface protonic conductivity in chemisorbed water in porous nanoscopic CeO2. Appl. Surf. Sci. 611, 155590 (2023).

    Article  CAS  Google Scholar 

  25. Haile, S. M., Boysen, D. A., Chisholm, C. R. I. & Merle, R. B. Solid acids as fuel cell electrolytes. Nature 419, 910–913 (2001).

    Article  Google Scholar 

  26. Wang, L. S., Patel, S. V., Truong, E., Hu, Y.-Y. & Haile, S. M. Phase behavior and superprotonic conductivity in the system (1 − x)CsH2PO4–xH3PO4: discovery of off-stoichiometric α-[Cs1−xHx]H2PO4. Chem. Mater. 34, 1809–1820 (2022).

    Article  Google Scholar 

  27. Joos, M., Kang, X., Merkle, R. & Maier, J. Further reading and extended materials examples for the impact of water incorporation on ion transport in solids. Edmond https://doi.org/10.17617/3.2ELASF (2024).

  28. Mitchell, J. B. et al. Confined interlayer water promotes structural stability for high-rate electrochemical proton intercalation in tungsten oxide hydrates. ACS Energy Lett. 4, 2805–2812 (2019).

    Article  CAS  Google Scholar 

  29. Mitchell, J. A., Chagnot, M. & Augustyn, V. Hydrous transition metal oxides for electrochemical energy and environmental applications. Annu. Rev. Mater. Res. 53, 1–23 (2023).

    Article  CAS  Google Scholar 

  30. Bubnova, O. et al. Semi-metallic polymers. Nat. Mater. 13, 190–194 (2014).

    Article  CAS  PubMed  Google Scholar 

  31. Paulsen, B. D., Fabiano, S. & Rivnay, J. Mixed ionic–electronic transport in polymers. Annu. Rev. Mater. Res. 51, 73–99 (2021).

    Article  CAS  Google Scholar 

  32. Wieland, M., Dingler, C., Merkle, R., Maier, J. & Ludwigs, S. Humidity-controlled water uptake and conductivities in ion and electron mixed conducting polythiophene films. ACS Appl. Mater. Interfaces 12, 6742–6751 (2020).

    Article  CAS  PubMed  Google Scholar 

  33. Stotz, S. & Wagner, C. Die Löslichkeit von Wasserdampf und Wasserstoff in festen Oxiden. Ber. Bunsenges. Phys. Chem. 70, 781–788 (1966).

    Article  CAS  Google Scholar 

  34. Iwahara, H., Esaka, T., Uchida, H. & Maeda, N. Proton conduction in sintered oxides and its application to steam electrolysis for hydrogen production. Solid State Ion. 3/4, 359–363 (1981).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  36. Bjorheim, T. S., Hoedl, M. F., Merkle, R., Kotomin, E. A. & Maier, J. Proton, hydroxide ion, and oxide ion affinities of closed-shell metal oxides: importance for the hydration reaction and correlation to electronic structure. J. Phys. Chem. C 124, 1277–1284 (2020).

    Article  Google Scholar 

  37. Kreuer, K. D., Schönherr, E. & Maier, J. Proton and oxygen diffusion in BaCeO3 based compounds: a combined thermal gravimetric analysis and conductivity study. Solid State Ion. 70, 278–284 (1994).

    Article  Google Scholar 

  38. Münch, W., Seifert, G., Kreuer, K. D. & Maier, J. A quantum molecular dynamics study of proton conduction phenomena in BaCeO3. Solid State Ion. 86, 647–652 (1996).

    Article  Google Scholar 

  39. Geneste, G. Proton transfer in barium zirconate: lattice reorganization, Landau–Zener curve-crossing approach. Solid State Ion. 232, 172–202 (2018).

    Article  Google Scholar 

  40. Duan, C., Huang, J., Sullivan, N. & O’Hayre, R. Proton-conducting oxides for energy conversion and storage. Appl. Phys. Rev. 7, 011314 (2020).

    Article  CAS  Google Scholar 

  41. 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).

    Article  CAS  Google Scholar 

  42. Papac, M., Stevanovic, V., Zakutayev, A. & O’Hayre, R. Triple ionic–electronic conducting oxides for next-generation electrochemical devices. Nat. Mater. 20, 301–313 (2021).

    Article  CAS  PubMed  Google Scholar 

  43. Merkle, R., Hoedl, M. F., Raimondi, G., Zohourian, R. & Maier, J. Oxides with mixed protonic and electronic conductivity. Annu. Rev. Mater. Res. 51, 461–493 (2021).

    Article  CAS  Google Scholar 

  44. Raimondi, G. et al. Interplay of chemical, electronic and structural effects in the triple-conducting BaFeO3–Ba(Zr,Y)O3 solid solution. Chem. Mater. 35, 8945–8957 (2023).

    Article  CAS  Google Scholar 

  45. Han, D., Okumura, Y., Nose, Y. & Uda, T. Synthesis of La1−xSrxSc1−yFeyO3−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).

    Article  CAS  Google Scholar 

  46. Yu, J. H., Lee, J. S. & Maier, J. Peculiar nonmonotonic water incorporation in oxides detected by local in situ optical absorption spectroscopy. Angew. Chem. Int. Ed. 46, 8992–8994 (2007).

    Article  CAS  Google Scholar 

  47. Yoo, H.-I., Yoon, J.-Y., Ha, J.-S. & Lee, C.-E. Hydration and oxidation kinetics of a proton conductor oxide, SrCe0.95Yb0.05O2.975. Phys. Chem. Chem. Phys. 10, 974–982 (2008).

    Article  CAS  PubMed  Google Scholar 

  48. Merkle, R., Sitte, W. & Maier, J. Water incorporation into materials with three mobile carriers: two-fold relaxation of the electromotive force in Fe-doped SrTiO3 and importance of hole trapping. Solid State Ion. 347, 115174 (2020).

    Article  CAS  Google Scholar 

  49. Kreuer, K. D. Aspects of the formation and mobility of protonic charge carriers and the stability of perovskite-type oxides. Solid State Ion. 125, 285–302 (1999).

    Article  CAS  Google Scholar 

  50. Kim, D. H., Kim, B. K. & Kim, Y. C. Energy barriers for proton migration in yttrium-doped barium zirconate super cell with Sigma 5 (310)/[001] tilt grain boundary. Solid State Ion. 213, 18–21 (2012).

    Article  CAS  Google Scholar 

  51. Iguchi, F., Chen, C. T., Yugami, H. & Kim, S. Direct evidence of potential barriers at grain boundaries in Y-doped BaZrO3 from dc-bias dependence measurements. J. Mater. Chem. 21, 16517–16523 (2011).

    Article  CAS  Google Scholar 

  52. Kjolseth, C. et al. Space-charge theory applied to the grain boundary impedance of proton conducting BaZr0.9Y0.1O3−d. Solid State Ion. 181, 268–275 (2010).

    Article  CAS  Google Scholar 

  53. Shirpour, M., Merkle, R., Lin, C. T. & Maier, J. Nonlinear electrical grain boundary properties in proton conducting Y-BaZrO3 supporting the space charge depletion model. Phys. Chem. Chem. Phys. 14, 730–740 (2012).

    Article  CAS  PubMed  Google Scholar 

  54. Gregori, G., Merkle, R. & Maier, J. Ion conduction and redistribution at interfaces in oxide systems. Prog. Mater Sci. 89, 252–305 (2017).

    Article  CAS  Google Scholar 

  55. Jia, C. L. & Urban, K. Atomic-resolution measurement of oxygen concentration in oxide materials. Science 303, 2001–2004 (2004).

    Article  CAS  PubMed  Google Scholar 

  56. Nyman, B. J., Helgee, E. E. & Wahnstrom, G. Oxygen vacancy segregation and space-charge effects in grain boundaries of dry and hydrated BaZrO3. Appl. Phys. Lett. 100, 061903 (2102).

    Article  Google Scholar 

  57. Lindman, A., Bjorheim, T. S. & Wahnstrom, G. Defect segregation to grain boundaries in BaZrO3 from first-principles free energy calculations. J. Mater. Chem. A 5, 13421–13429 (2017).

    Article  CAS  Google Scholar 

  58. Iguchi, F., Sata, N., Tsurui, T. & Yugami, H. Microstructures and grain boundary conductivity of BaZr1−xYxO3 (x = 0.05, 0.10, 0.15) ceramics. Solid State Ion. 178, 691–695 (2007).

    Article  CAS  Google Scholar 

  59. Shirpour, M. et al. Dopant segregation and space charge effects in proton-conducting BaZrO3 perovskites. J. Phys. Chem. C 116, 2453–2461 (2012).

    Article  CAS  Google Scholar 

  60. Clark, D. R. et al. Probing grain-boundary chemistry and electronic structure in proton-conducting oxides by atom probe tomography. Nano Lett. 16, 6924–6930 (2016).

    Article  CAS  PubMed  Google Scholar 

  61. Huang, Y., Merkle, R. & Maier, J. Effects of NiO addition on sintering and proton uptake of Ba(Zr,Ce,Y)O3−δ. J. Mater. Chem. A 9, 14775–14785 (2021).

    Article  CAS  Google Scholar 

  62. Ngabonziza, P. et al. 2D doping of proton conductors: BaZrO3-based heterostructures. Adv. Energy Mater. 11, 2003267 (2021).

    Article  CAS  Google Scholar 

  63. Draber, F. M. et al. Nanoscale percolation in doped BaZrO3 for high proton mobility. Nat. Mater. 19, 338–347 (2020).

    Article  CAS  PubMed  Google Scholar 

  64. Kusoglu, A. & Weber, A. Z. New insights into perfluorinated sulfonic-acid ionomers. Chem. Rev. 117, 987–1104 (2017).

    Article  CAS  PubMed  Google Scholar 

  65. Kreuer, K.-D. & Portale, G. A critical revision of the nano-morphology of proton conducting ionomers and polyelectrolytes for fuel cell applications. Adv. Funct. Mater. 23, 5390–5397 (2013).

    Article  CAS  Google Scholar 

  66. Shin, D. W., Guiver, M. D. & Lee, Y. M. Hydrocarbon-based polymer electrolyte membranes: importance of morphology on ion transport and membrane stability. Chem. Rev. 117, 4759–4805 (2017).

    Article  CAS  PubMed  Google Scholar 

  67. Kreuer, K. D. Ion conducting membranes for fuel cells and other electrochemical devices. Chem. Mater. 26, 361–380 (2014).

    Article  CAS  Google Scholar 

  68. Varcoe, J. R. et al. Anion-exchange membranes in electrochemical energy systems. Energy Environ. Sci. 7, 3135–3191 (2014).

    Article  CAS  Google Scholar 

  69. Kreuer, K. D. The role of internal pressure for the hydration and transport properties of ionomers and polyelectrolytes. Solid State Ion. 252, 93–101 (2013); corrigendum 328, 35–36 (2018).

  70. Miyake, J. et al. Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells. Sci. Adv. 3, eaao0476 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  71. Dekel, D. R. Review of cell performance in anion exchange membrane fuel cells. J. Power Sources 375, 158–169 (2018).

    Article  CAS  Google Scholar 

  72. Xue, J. et al. Toward alkaline‑stable anion exchange membranes in fuel cells: cycloaliphatic quaternary ammonium‑based anion conductors. Electrochem. Energy Rev. 5, 348–400 (2022).

    Article  CAS  Google Scholar 

  73. Mardle, P., Chen, B. & Holdcroft, S. Opportunities of ionomer development for anion-exchange membrane water electrolysis. ACS Energy Lett. 8, 3330–3342 (2023).

    Article  CAS  Google Scholar 

  74. Schuster, M., Kreuer, K.-D., Andersen, H. T. & Maier, J. Sulfonated poly(phenylene sulfone) polymers as hydrolytically and thermooxidatively stable proton conducting ionomers. Macromolecules 40, 598–607 (2007).

    Article  CAS  Google Scholar 

  75. Bae, B., Miyatake, K. & Watanabe, M. Sulfonated poly(arylene ether sulfone ketone) multiblock copolymers with highly sulfonated block. synthesis and properties. Macromolecules 43, 2684–2691 (2010).

    Article  CAS  Google Scholar 

  76. Kraytsberg, A. & Ein-Eli, Y. Review of advanced materials for proton exchange membrane fuel cells. Energy Fuels 28, 7303–7330 (2014).

    Article  CAS  Google Scholar 

  77. Kreuer, K.-D., Wohlfarth, A., de Araujo, C. C., Fuchs, A. & Maier, J. Single alkaline-ion (Li+, Na+) conductors by ion exchange of proton-conducting ionomers and polyelectrolytes. ChemPhysChem 12, 2258–2260 (2011).

    Article  Google Scholar 

  78. Bouchet, R. et al. Single-ion BAB triblock copolymers as highly efficient electrolytes for lithium-metal batteries. Nat. Mater. 12, 452–457 (2013).

    Article  CAS  PubMed  Google Scholar 

  79. Bhattacharyya, A. J. & Maier, J. Second phase effects on the conductivity of non-aqueous salt solutions: ‘soggy sand electrolytes’. Adv. Mater. 16, 811–814 (2004).

    Article  CAS  Google Scholar 

  80. Deng, R. et al. ‘Soggy-sand’ chemistry for high-voltage aqueous zinc-ion batteries. Adv. Mater. 36, 2311153 (2024).

    Article  CAS  Google Scholar 

  81. Xue, Z., Heb, D. & Xie, X. Poly(ethylene oxide)-based electrolytes for lithium ion batteries. J. Mater. Chem. A 3, 19218–19253 (2015).

    Article  CAS  Google Scholar 

  82. Whittingham, M. S. Hydrogen motion in oxides: from insulators to bronzes. Solid State Ion. 168, 255–263 (2004).

    Article  CAS  Google Scholar 

  83. Joos, M. et al. Impact of hydration on ion transport in Li2Sn2S5xH2O. J. Mater. Chem. A 9, 16532–16544 (2021).

    Article  CAS  Google Scholar 

  84. Hatz, A.-K. et al. Fast water-assisted lithium ion conduction in restacked lithium tin sulfide nanosheets. Chem. Mater. 33, 7337–7349 (2021).

    Article  CAS  Google Scholar 

  85. Simon, U. & Franke, M. E. Electrical properties of nanoscaled host/guest compounds. Micropor. Mesopor. Mater. 41, 1–36 (2000).

    Article  CAS  Google Scholar 

  86. Lim, D. W. & Kitagawa, H. Proton transport in metal–organic frameworks. Chem. Rev. 120, 8416–8467 (2020).

    Article  CAS  PubMed  Google Scholar 

  87. Jache, B. & Adelhelm, P. Use of graphite as a highly reversible electrode with superior cycle life for sodium-ion batteries by making use of co-intercalation phenomena. Angew. Chem. Int. Ed. 53, 10169–10173 (2014).

    Article  CAS  Google Scholar 

  88. Park, J., Xu, Z.-L. & Kang, K. Solvated ion intercalation in graphite: sodium and beyond. Front. Chem. 8, 432 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  89. Joos, M. et al. On the crystal structures of lithium thiocyanate monohydrate LiSCN⋅1H2O and the phase diagram LiSCN–H2O. J. Phys. Chem. Solids 160, 110299 (2022).

    Article  CAS  Google Scholar 

  90. Suo, L. et al. ‘Water-in-salt’ electrolyte enables high-voltage aqueous lithium-ion chemistries. Science 350, 938–943 (2015).

    Article  CAS  PubMed  Google Scholar 

  91. Jeon, J. & Cho, M. Ion transport in super-concentrated aqueous electrolytes for lithium-ion batteries. J. Phys. Chem. C 125, 23622–23633 (2021).

    Article  CAS  Google Scholar 

  92. Han, K. S. et al. Origin of unusual acidity and Li+ diffusivity in a series of water-in-salt electrolytes. J. Phys. Chem. B 124, 5284–5291 (2020).

    Article  CAS  PubMed  Google Scholar 

  93. Guo, Y. et al. Ion transport in semi-solid in-salt electrolytes: LiTFSI–H2O as a model system. J. Mater. Chem. A 11, 3427–3436 (2023).

    Article  CAS  Google Scholar 

  94. Xu, J. et al. Aqueous electrolyte design for super-stable 2.5 V LiMn2O4 || Li4Ti5O12 pouch cells. Nat. Energy 7, 186–193 (2022).

    Article  CAS  Google Scholar 

  95. Stub, S. Ø., Vøllestad, E. & Norby, T. Mechanisms of protonic surface transport in porous oxides: example of YSZ. J. Phys. Chem. C 121, 12817–12825 (2017).

    Article  CAS  Google Scholar 

  96. Kim, S. et al. On the conduction pathway for protons in nanocrystalline yttria-stabilized zirconia. Phys. Chem. Chem. Phys. 11, 3035–3038 (2009).

    Article  CAS  PubMed  Google Scholar 

  97. Raz, S., Sasaki, K., Maier, J. & Riess, I. Characterization of adsorbed water layers on Y2O3-doped ZrO2. Solid State Ion. 143, 181–204 (2001).

    Article  CAS  Google Scholar 

  98. Hinterberg, J. et al. 1H-NMR measurements of proton mobility in nano-crystalline YSZ. Phys. Chem. Chem. Phys. 15, 19825–19830 (2013).

    Article  CAS  PubMed  Google Scholar 

  99. Gregori, G., Shirpour, M. & Maier, J. Proton conduction in dense and porous nanocrystalline ceria thin films. Adv. Funct. Mater. 23, 5861–5867 (2013).

    Article  CAS  Google Scholar 

  100. Sato, R., Ohkuma, S., Shibuta, Y., Shimojo, F. & Yamaguchi, S. Proton migration on hydrated surface of cubic ZrO2: ab initio molecular dynamics simulation. J. Phys. Chem. C 119, 28925–28933 (2015).

    Article  CAS  Google Scholar 

  101. England, W. A., Gross, M. G., Hamnett, A., Wiseman, P. J. & Goodenough, J. B. Fast proton conduction in inorganic ion-exchange compounds. Solid State Ion. 1, 231–249 (1980).

    Article  CAS  Google Scholar 

  102. Yang, J., Youssef, M. & Yildiz, B. Charged species redistribution at electrochemical interfaces: a model system of the zirconium oxide/water interface. Phys. Chem. Chem. Phys. 25, 6380–6391 (2023).

    Article  CAS  PubMed  Google Scholar 

  103. Norby, T., Sun, X. & Vøllestad, E. A brick layer model for surface conduction in porous ceramics. Solid State Ion. 398, 116269 (2023).

    Article  CAS  Google Scholar 

  104. Fleig, J. & Maier, J. The impedance of imperfect electrode contacts on solid electrolytes. Solid State Ion. 85, 17–24 (1996).

    Article  CAS  Google Scholar 

  105. Maier, J. Chemical potential of charge carriers in solids. Z. Phys. Chem. 219, 35–46 (2005).

    Article  CAS  Google Scholar 

  106. Israelachvili, J. N. & Pashley, R. M. Molecular layering of water at surfaces and origin of repulsive hydration forces. Nature 306, 249–250 (1983).

    Article  CAS  Google Scholar 

  107. Krämer, A., Vossen, M. & Forstmann, F. The influence of image interactions on the structure of water and electrolytes in front of a metal surface. J. Chem. Phys. 106, 2792–2800 (1997).

    Article  Google Scholar 

  108. Fenter, P. & Sturchio, N. C. Mineral–water interfacial structures revealed by synchrotron X-ray scattering. Prog. Surf. Sci. 77, 171–258 (2004).

    Article  CAS  Google Scholar 

  109. Gao, Z., Giovambattista, N. & Sahin, O. Phase diagram of water confined by graphene. Sci. Rep. 8, 6228 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  110. Knight, A. W., Kalugin, N. G., Coker, E. & Ilgen, A. G. Water properties under nano-scale confinement. Sci. Rep. 9, 8246 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  111. Gonella, G. et al. Water at charged interfaces. Nat. Rev. Chem. 5, 466–485 (2021).

    Article  CAS  PubMed  Google Scholar 

  112. Kreuer, K.-D., Paddison, S. J., Spohr, E. & Schuster, M. Transport in proton conductors for fuel-cell applications: simulations, elementary reactions, and phenomenology. Chem. Rev. 104, 4637–4678 (2004).

    Article  CAS  PubMed  Google Scholar 

  113. MacKinnon, R. Potassium channels and the atomic basis of selective ion conduction. Angew. Chem. Int. Ed. 43, 4265–4277 (2004).

    Article  CAS  Google Scholar 

  114. Gelenter, M. D. et al. Water orientation and dynamics in the closed and open influenza B virus M2 proton channels. Commun. Biol. 4, 338 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  115. Hara, S. & Miyayama, M. Proton conductivity of superacidic sulfated zirconia. Solid State Ion. 168, 111–116 (2004).

    Article  CAS  Google Scholar 

  116. Aliouane, N. et al. Investigation of hydration and protonic conductivity of H-montmorillonite. Solid State Ion. 148, 103–110 (2002).

    Article  CAS  Google Scholar 

  117. Felica, V. & Tavares, A. C. Faujasite zeolites as solid electrolyte for low temperature fuel cells. Solid State Ion. 194, 53–61 (2011).

    Article  Google Scholar 

  118. Peng, Y. et al. Mechanoassisted synthesis of sulfonated covalent organic frameworks with high intrinsic proton conductivity. ACS Appl. Mater. Interfaces 8, 18505–18512 (2016).

    Article  CAS  PubMed  Google Scholar 

  119. Morris, D. R. & Sun, X. Water-sorption and transport properties of Nafion 117 H. J. Appl. Polym. Sci. 50, 1445–1452 (1993).

    Article  CAS  Google Scholar 

  120. Liu, J., He, X., Zhang, J. Z. & Qi, L.-W. Hydrogen-bond structure dynamics in bulk water: insights from ab initio simulations with coupled cluster theory. Chem. Sci. 9, 2065–2073 (2018).

    Article  CAS  PubMed  Google Scholar 

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

    Article  CAS  Google Scholar 

  122. Maier, J. Physical Chemistry of Ionic Materials 2nd edn (Wiley, 2023)

  123. Kröger, F. A. Chemistry of Imperfect Crystals (North–Holland, 1964)

  124. Rickert, H. Electrochemistry of Solids (Springer, 1982).

  125. Maier, J. Building versus structure elements: ionic charge carriers in solids. Z. Phys. Chem. 226, 863–870 (2012).

    Article  CAS  Google Scholar 

  126. Xiao, C., Chen, C.-C. & Maier, J. Discrete modeling of space charge zones in solids. Phys. Chem. Chem. Phys. 24, 11945–11957 (2022).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We thank numerous colleagues in the Max Planck Institute for Solid State Research and the ‘Solid State Ionics’ community for valuable discussions concerning hydration effects and proton transport in a large range of materials. Graphics support by C. Blaga, and reading of the proofs by C. Schneider, are appreciated.

Author information

Authors and Affiliations

  1. Max Planck Institute for Solid State Research, Stuttgart, Germany

    Markus Joos, Xiaolan Kang, Rotraut Merkle & Joachim Maier

Authors
  1. Markus Joos
    View author publications

    Search author on:PubMed Google Scholar

  2. Xiaolan Kang
    View author publications

    Search author on:PubMed Google Scholar

  3. Rotraut Merkle
    View author publications

    Search author on:PubMed Google Scholar

  4. Joachim Maier
    View author publications

    Search author on:PubMed Google Scholar

Corresponding author

Correspondence to Joachim Maier.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

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

Additional information

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

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Joos, M., Kang, X., Merkle, R. et al. Water uptake of solids and its impact on ion transport. Nat. Mater. 24, 821–834 (2025). https://doi.org/10.1038/s41563-025-02143-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41563-025-02143-8

Search

Advanced search

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