Article | Published:

Synergistic, ultrafast mass storage and removal in artificial mixed conductors

Nature volume 536, pages 159164 (11 August 2016) | Download Citation

  • A Corrigendum to this article was published on 26 October 2016

Abstract

Mixed conductors—single phases that conduct electronically and ionically—enable stoichiometric variations in a material and, therefore, mass storage and redistribution, for example, in battery electrodes. We have considered how such properties may be achieved synergistically in solid two-phase systems, forming artificial mixed conductors. Previously investigated composites suffered from poor kinetics and did not allow for a clear determination of such stoichiometric variations. Here we show, using electrochemical and chemical methods, that a melt-processed composite of the ‘super-ionic’ conductor RbAg4I5 and the electronic conductor graphite exhibits both a remarkable silver excess and a silver deficiency, similar to those found in single-phase mixed conductors, even though such behaviour is not possible in the individual phases. Furthermore, the kinetics of silver uptake and release is very fast. Evaluating the upper limit of the relaxation time set by interfacial ambipolar diffusion reveals chemical diffusion coefficients that are even higher than those achieved for sodium chloride in bulk liquid water. These results could potentially stimulate systematic research into powerful, even mesoscopic, artificial mixed conductors.

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References

  1. 1.

    & Solid State Ionics Ch. 5, 47–63 (VCH, 1990)

  2. 2.

    Semiconduction and mixed ionic–electronic conduction in nonstoichiometric oxides: impact and control. Solid State Ion. 94, 63–74 (1997)

  3. 3.

    Mixed ionic–electronic conductors—material properties and applications. Solid State Ion. 157, 1–17 (2003)

  4. 4.

    Nanoionics: ion transport and electrochemical storage in confined systems. Nat. Mater. 4, 805–815 (2005)

  5. 5.

    Equations for transport in solid oxides and sulfides of transition metals. Prog. Solid State Chem. 10, 3–16 (1975)

  6. 6.

    & Generalised equivalent circuits for mass and charge transport: chemical capacitance and its implications. Phys. Chem. Chem. Phys. 3, 1668–1678 (2001)

  7. 7.

    Thermodynamics of electrochemical lithium storage. Angew. Chem. Int. Ed. 52, 4998–5026 (2013)

  8. 8.

    & in The CRC Handbook of Solid State Electrochemistry (eds & ) 481–554 (CRC Press, 1997)

  9. 9.

    , & Advances and new directions in gas-sensing devices. Acta Mater. 61, 974–1000 (2013)

  10. 10.

    & Defect chemistry of the high-Tc superconductors. Adv. Mater. 3, 292–297 (1991)

  11. 11.

    & Nanoionics-based resistive switching memories. Nat. Mater. 6, 833–840 (2007)

  12. 12.

    et al. Reversible switching between p- and n-type conduction in the semiconductor Ag10Te4Br3. Nat. Mater. 8, 101–108 (2009)

  13. 13.

    Ag2S—the physical chemistry of an inorganic material. Prog. Solid State Chem. 13, 119–157 (1980)

  14. 14.

    & Chemical diffusion in β-Ag2Te. Solid State Ion. 141–142, 331–334 (2001)

  15. 15.

    & Coulometric titration at low temperatures—nonstoichiometric silver selenide. Solid State Ion. 170, 129–133 (2004)

  16. 16.

    , & The chemical diffusion coefficient in (low temperature) α-Ag2S determined by an electrochemical relaxation method. Solid State Ion. 11, 213–219 (1983)

  17. 17.

    Chemical diffusion in mixed conductors: α′-Ag2Te and β-Ag2Se. Solid State Ion. 94, 85–90 (1997)

  18. 18.

    & Thermodynamic investigations of Ag2Se. Ber. Bunsenges. Phys. Chem 85, 7–14 (1981)

  19. 19.

    et al. Defect chemistry of La2−xSrxCuO4−δ: oxygen nonstoichiometry and thermodynamic stability. J. Solid State Chem. 131, 150–159 (1997)

  20. 20.

    , & Nonstoichiometry and reductive decomposition of CaMnO3−δ. Solid State Ion. 176, 217–223 (2005)

  21. 21.

    , , & Phase stability and oxygen nonstoichiometry of highly oxygen-deficient perovskite-type oxides: a case study of (Ba, Sr)(Co, Fe)O3−δ. Chem. Mater. 24, 269–274 (2012)

  22. 22.

    AgI-type solid electrolytes. Prog. Solid State Chem. 11, 345–402 (1976)

  23. 23.

    et al. Mixed ionic–electronic conducting (MIEC) ceramic-based membranes for oxygen separation. J. Membr. Sci. 320, 13–41 (2008)

  24. 24.

    in Modern Aspects of Electrochemistry Vol. 41 (eds et al.) 1–138 (Springer, 2007)

  25. 25.

    , , & Thermodynamics of lithium storage at abrupt junctions: modeling and experimental evidence. Phys. Rev. Lett. 112, 208301 (2014)

  26. 26.

    et al. “Job-sharing” storage of hydrogen in Ru/Li2O nanocomposites. Nano Lett. 15, 4170–4175 (2015)

  27. 27.

    Kröger–Vink diagrams for boundary regions. Solid State Ion. 32–33, 727–733 (1989)

  28. 28.

    & Influence of temperature and interface charge on the grain-boundary conductivity in acceptor-doped SrTiO3 ceramics. J. Appl. Phys. 83, 2083–2092 (1998)

  29. 29.

    , , , & Defect and transport properties of nanocrystalline CeO2−x. Appl. Phys. Lett. 69, 185–187 (1996)

  30. 30.

    & On the conductivity mechanism of nanocrystalline ceria. J. Electrochem. Soc. 149, J73–J83 (2002)

  31. 31.

    et al. Oxygen tracer diffusion in donor doped barium titanate. J. Appl. Phys. 110, 043531 (2011)

  32. 32.

    , & Oxygen nonstoichiometry of nanosized ceria powder. Surf. Sci. 549, 196–202 (2004)

  33. 33.

    , & Mesoscopic charge carriers chemistry in nanocrystalline SrTiO3. Angew. Chem. Int. Ed. 49, 10123–10126 (2010)

  34. 34.

    Interfacial effects on Ag:S nonstoichiometry in silver sulfide/alumina composites. Solid State Ion. 21, 117–129 (1986)

  35. 35.

    & Electronic properties of graphite: a unified theoretical study. Phys. Rev. B 25, 4126–4141 (1982)

  36. 36.

    , , & Graphene-based composites. Chem. Soc. Rev. 41, 666–686 (2012)

  37. 37.

    & The transient behavior of graphite-silver iodide and platinum-silver iodide interfaces in a solid-state system. J. Electrochem. Soc. 118, 72–78 (1971)

  38. 38.

    A solid state electrochemical capacitor. 141st Meeting of The Electrochemical Society abstr. no. 175, p. 446 (Houston, 1972)

  39. 39.

    Electrode capacitance in silver-halide solid electrolyte cells. I. Room temperature graphite and platinum electrodes. J. Electrochem. Soc. 121, 632–639 (1974)

  40. 40.

    & The double layer structure at the metal–solid electrolyte interface. Solid State Ion. 94, 181–187 (1997)

  41. 41.

    , & Electrochemical properties of RbAg4I5 solid electrolyte. I. Conductivity studies. J. Electrochem. Soc. 118, 86–89 (1971)

  42. 42.

    , , & An electrochemical investigation into the lithium insertion properties of LixCoO2. Electrochim. Acta 41, 2481–2488 (1996)

  43. 43.

    Mass transport in the presence of internal defect reactions—concept of conservative ensembles: I, chemical diffusion in pure compounds. J. Am. Ceram. Soc. 76, 1212–1217 (1993)

  44. 44.

    in Advances in Electrochemistry and Electrochemical Engineering Vol. 6 (ed. ) 329–397 (Wiley-Interscience, 1967)

  45. 45.

    & Electronic transport in calcia-stabilized zirconia. Proc. Brit. Ceram. Soc. 19, 229–263 (1971)

  46. 46.

    et al. Ultrahigh-power micrometre-sized supercapacitors based on onion-like carbon. Nat. Nanotechnol. 5, 651–654 (2010)

  47. 47.

    , , & Mesoscopic fast ion conduction in nanometre-scale planar heterostructures. Nature 408, 946–949 (2000)

  48. 48.

    Diffusion: Mass Transfer in Fluid Systems (Cambridge Univ. Press, 1997)

  49. 49.

    , & Ambipolar diffusion in RbAg4I5. Solid State Ion. 67, 311–316 (1994)

  50. 50.

    & Electrochemical determinations of the chemical diffusion coefficient and non-stoichiometry in AgCl. Solid State Ion. 6, 85–91 (1982)

  51. 51.

    , & Electrochemical characteristics and impedance spectroscopy studies of carbon-carbon supercapacitors. J. Electrochem. Soc. 150, A292–A300 (2003)

  52. 52.

    Electrochemical cell for composition dependent measurements of chemical diffusion coefficients and ionic conductivities on mixed conductors and application to silver telluride at 160 °C. Solid State Ion. 59, 117–124 (1993)

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Acknowledgements

We acknowledge technical support by A. Fuchs (N2 isotherms), J. Liu (SEM), H. Hoier (XRD), V. Duppel (TEM) and R. Merkle (TGA). We are grateful to C. Wu for discussions and B. Lotsch for reading the manuscript.

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Affiliations

  1. Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany

    • Chia-Chin Chen
    • , Lijun Fu
    •  & Joachim Maier

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Contributions

The scientific conception is due to J.M. C.-C.C. designed and executed the experiments. L.F. assisted in experiments and discussions. C.-C.C. and J.M. analysed the data, are responsible for the theoretical treatment and wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Joachim Maier.

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    Supplementary Information

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https://doi.org/10.1038/nature19078

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