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Fabrication and structural characterization of self-supporting electrolyte membranes for a micro solid-oxide fuel cell

Published online by Cambridge University Press:  03 March 2011

Chelsey D. Baertsch
Affiliation:
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Klavs F. Jensen*
Affiliation:
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Joshua L. Hertz
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Harry L. Tuller
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Srikar T. Vengallatore
Affiliation:
Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
S. Mark Spearing
Affiliation:
Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Martin A. Schmidt
Affiliation:
Microsystems Technology Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
*
b)Address all correspondence to this author. e-mail: kfjensen@mit.edu
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Abstract

Micromachined fuel cells are among a class of microscale devices being explored for portable power generation. In this paper, we report processing and geometric design criteria for the fabrication of free-standing electrolyte membranes for microscale solid-oxide fuel cells. Submicron, dense, nanocrystalline yttria-stabilized zirconia (YSZ) and gadolinium-doped ceria (GDC) films were deposited onto silicon nitride membranes using electron-beam evaporation and sputter deposition. Selective silicon nitride removal leads to free-standing, square, electrolyte membranes with side dimensions as large as 1025 μm for YSZ and 525 μm for GDC, with high processing yields for YSZ. Residual stresses are tensile (+85 to +235 MPa) and compressive (–865 to -155 MPa) in as-deposited evaporated and sputtered films, respectively. Tensile evaporated films fail via brittle fracture during annealing at temperatures below 773 K; thermal limitations are dependent on the film thickness to membrane size aspect ratio. Sputtered films with compressive residual stresses show superior mechanical and thermal stability than evaporated films. Sputtered 1025-μm membranes survive annealing at 773 K, which leads to the generation of tensile stresses and brittle fracture at elevated temperatures (923 K).

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Articles
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1.Morse, J.D., Jankowski, A.F., Graff, R.T. andHayes, J.P.: Novel proton exchange membrane thin-film fuel cell for microscale energy conversion. J. Vac. Sci. Technol. A 18 2003 (2000).CrossRefGoogle Scholar
2.Heinzel, A., Hebling, C., Muller, M., Zedda, M. andMuller, C.: Fuel cells for low power applications, J. Power Sources 105 250 (2002).CrossRefGoogle Scholar
3.Voss, H. andHuff, J.: Portable fuel cell power generator. J. Power Sources 65 155 (1997).CrossRefGoogle Scholar
4.Chang, H., Kim, J.R., Cho, J.H., Kim, H.K. andChoi, K.H.: Materials and processes for small fuel cells. Solid State Ionics 148 601 (2002).CrossRefGoogle Scholar
5.Ren, X., Zelenay, P., Thomas, S., Davey, J. andGottesfeld, S.: Recent advances in direct methanol fuel cells at Los Alamos National Laboratory. J. Power Sources 86 111 (2000).CrossRefGoogle Scholar
6.Park, S.D., Vohs, J.M. andGorte, R.J.: Direct oxidation of hydrocarbons in a solid-oxide fuel cell. Nature 404 265 (2000).CrossRefGoogle Scholar
7.Jankowski, A.F., Graff, R.T., Hayes, J.P., and Morse, J.D.: Testing of solid-oxide fuel cells for micro to macro power generation, in Proceedings of the Sixth International Symposium on SOFC, edited by Dokiya, M. and Singhal, S.C. (Electrochem. Soc. Proc. 99-119, Pennington, NJ, 1999), p. 932.Google Scholar
8.de Souza, S.: S.J. Visco, and L.D. De Jonghe, Thin-film solid oxide fuel cell with high performance at low-temperature. Solid State Ionics 98 57 (1997).CrossRefGoogle Scholar
9.Arana, L.R., Schaevitz, S.B., Franz, A.J., Schmidt, M.A. andJensen, K.F.: A microfabricated suspended-tube chemical reactor for thermally efficient fuel processing. J. Microelectromech. Syst. 12 600 (2002).CrossRefGoogle Scholar
10.Steele, B.C.H. andHeinzel, A.: Materials for fuel-cell technologies. Nature 414 345 (2001).CrossRefGoogle ScholarPubMed
11.Srikar, V.T., Turner, K.T., Ie, T.Y.A. andSpearing, S.M.: Structural design considerations for micromachined solid-oxide fuel cells. J. Power Sources 125, 62 (2004).CrossRefGoogle Scholar
12.Nix, W.D.: Mechanical properties of thin-films. Metall. Trans. 20A 2217 (1989).CrossRefGoogle Scholar
13.Ami, T., Ishida, Y., Nagasawa, N., Machida, A. andSuzuki, M.: Room-temperature epitaxial growth of CeO2(001) thin films on Si(001) substrates by electron beam evaporation. Appl. Phys. Lett. 78 1361 (2001).CrossRefGoogle Scholar
14.Hass, D.D., Parrish, P.A. andWadley, H.N.G.: Electron beam directed vapor deposition of thermal-barrier coatings. J. Vac. Sci. Technol. A 16 3396 (1998).CrossRefGoogle Scholar
15.Hartmanova, M., Thurzo, I., Jergel, M., Bartos, J., Kadlec, F., Zelenzny, V., Tunega, D., Kundracik, F., Chromik, S. andBrunel, M.: Characterization of yttria-stabilized zirconia thin films deposited by electron beam evaporation on silicon substrates. J. Mater. Sci. 33 969 (1998).CrossRefGoogle Scholar
16.Greene, J.E., Wickersham, C.E., Zilko, J.L., Welsh, L.B. andSzofran, F.R.: Morphological and electrical properties of RF sputtered Y2O3-doped ZrO2 thin films. J. Vac. Sci. Technol. 13 72 (1976).CrossRefGoogle Scholar
17.Nagata, A. andOkayama, H.: Characterization of solid oxide fuel cell device having a three-layer film structure grown by RF magnetron sputtering. Vac. 66 523 (2002).CrossRefGoogle Scholar
18.Thiele, E.S., Wang, L.S., Mason, T.O. andBarnett, S.A.: Deposition and properties of yttria-stabilized zirconia thin films using reactive direct-current magnetron sputtering. J. Vac. Sci. Technol. A 9 3054 (1991).CrossRefGoogle Scholar
19.Unal, O., Mitchell, T.E. andHeuer, A.H.: Microstructures of Y2O3-stabilized ZrO2 electron-beam physical vapor deposition coatings on Ni-base superalloys. J. Am. Ceram. Soc. 77 984 (1994).CrossRefGoogle Scholar
20.Tuller, H.L.: Solid state electrochemical systems—Opportunities for nanofabricated or nanostructured materials. J. Electroceramics 1 211 (1997).CrossRefGoogle Scholar
21.Ying, J.Y. andSun, T.: Research needs assessment on nanostructured catalysts. J. Electroceramics 1 219 (1997).CrossRefGoogle Scholar
22.Lappalainen, J., Kek, D. andTuller, H.L. Investigation of Pt/Si/CeO2/Pt MOS device structure by impedance spectroscopy, in Electrically Based Microstructural Characterization III, edited by Gerhardt, R.A., Washabaugh, A.P., Alim, M.A., and Choi, G.M. (Mater. Res. Soc. Symp. Proc. 699, Warrendale, PA, 2002), p. 173, R5.1.1Google Scholar
23.Tschope, A. andBirringer, R.: Grain size dependence of electrical conductivity in polycrystalline cerium oxide. J. Electroceramics 7 169 (2001).CrossRefGoogle Scholar
24.Kim, S. andMaier, J.: On the conductivity mechanism of nanocrystalline ceria. J. Electrochem. Soc. 149 J73 (2002).CrossRefGoogle Scholar
25.Suzuki, T., Kosacki, I. andAnderson, H.U.: Microstructure-electrical conductivity relationships in nanocrystalline ceria thin films. Solid State Ionics 151 111 (2002).CrossRefGoogle Scholar
26.Kosacki, I., Suzuki, T., Petrovsky, V. andAnderson, H.U.: Electrical conductivity of nanocrystalline ceria and zirconia thin films. Solid State Ionics 136 1225 (2000).CrossRefGoogle Scholar
27.Bruschi, P., Diligenti, A., Nannini, A. andPiotto, M.: Technology of integrable free-standing yttria-stabilized zirconia membranes. Thin Solid Films 346 251 (1999).CrossRefGoogle Scholar
28.Senturia, S.D.: Microsystem Design (Kluwer, Norwell, MA, 2001)CrossRefGoogle Scholar
29.Proost, J. andSpaepen, F.: Evolution of the growth stress, stiffness, and microstructure of alumina thin films during vapor deposition. J. Appl. Phys. 91 204 (2002).CrossRefGoogle Scholar
30.Hoffmann, D.W. andThornton, J.A.: Compressive stress transition in Al, V, Zr, Nb and W metal-films sputtered at low working pressures. Thin Solid Films 45 387 (1977).CrossRefGoogle Scholar
31.Knoll, R.W. andBradley, E.R.: Correlation between the stress and microstructure in bias-sputtered ZrO2-Y2O3 films. Thin Solid Films 117 201 (1984).CrossRefGoogle Scholar
32.Srikar, V.T. andSpearing, S.M.: A critical review of microscale mechanical testing methods used in the design of microelectromechanical systems. Exp. Mech . 43 238 (2003).CrossRefGoogle Scholar
33.Ziebart, V., Paul, O. andBaltes, H.: Strongly buckled square micromachined membranes. J. Microelectromech. Syst. 8 423 (1999).CrossRefGoogle Scholar
34.Wang, S.R., Katsuki, M., Hashimoto, T. andDokiya, M.: Expansion behavior of Ce1-yGdyO2.0-0.5y-δ under various oxygen partial pressures evaluated by HTXRD. J. Electrochem. Soc. 150 A952 (2003).CrossRefGoogle Scholar
35.Mogensen, M., Lindegaard, T., Hansen, U.R. andMogensen, G.: Physical properties of mixed conductor solid oxide fuel-cell anodes of doped CeO2. J. Electrochem. Soc. 141 2122 (1994).CrossRefGoogle Scholar
36.Atkinson, A. andRamos, T.M.G.M.: Chemically-induced stresses in ceramic oxygen ion-conducting membranes. Solid State Ionics 129 259 (2000).CrossRefGoogle Scholar
37.Ugural, A.C., Stresses in Plates and Shells, 2nd ed., (McGraw-Hill, New York, 1999).Google Scholar
38.Hertz, J.L. and Tuller, H.L.: Electrochemical characterization of thin films for a micro-solid oxide fuel cell. J. Electroceram. (2003, in press).Google Scholar