DEPOSITION OF THE La_1-хSr_xScO_3-α PROTON ELECTROLYTE THIN FILMS ON La_0.6Sr_0.4MnO_3-α SUPPORTING CATHODE MATERIAL

Based on LaScO₃ proton-conducting oxides with a perovskite structure, having high chemical stability to water vapor, are promising proton electrolytes for SOFC, but they are poorly studied in the form of thin films. Lanthanum-strontium manganite is one of the most common materials for the SOFC cathode. The aim of this work is to study the effect of the La_0.6Sr_0.4MnO_3-α cathode substrate composition on the properties of La_1-xSr_xScO₃ (0.01, 0.05 and 0.10) thin-film proton electrolytes, obtained by simple centrifugation of the film-forming solution. The properties of La_1-xSr_xScO₃ in the form of ceramic and thin-film samples are compared. The experiment showed that the films La_1-xSr_xScO₃ at 5–30-fold deposition on cathode substrates form continuous coatings with a grain size of 50–200 nm, which do not contain transverse pores. These results have a fundamental importance for the development of SOFC with ultra-thin film electrolyte on a supporting electrode. Under dry and wet air, the electrical conductivity of La_0.6Sr0.4MnO_3-α/ La_1-xSr_xScO₃ /Pt cells is found to be bulk conductivity and to rise with increasing atmospheric humidity which indicates an increase in the contribution of proton conductivity. In this case, the grain-boundary resistance of the material and the polarization resistance of the electrodes are practically not realized. The conductivity of LSS films is 1–2 orders of magnitude higher than the bulk conductivity of ceramic samples of similar composition and has low activation energy. The observed differences in the conductive properties of films are explained by the interaction of related perovskites of the scandate and lanthanum manganite. The data obtained may be of interest to specialists in the fields of hydrogen energy, electrochemistry, materials science, the development of electrochemical devices: sensors and fuel cells.

1. [1] Laguna-Bercero M.A. Recent advances in high temperature electrolysis using solid oxide fuel cells. A review Journal of Power Sources, 2012;203:4–16.

2. [2] Kawada T., Mizusaki J. Current Electrolytes and Catalysts. Handbook of Fuel Cells: Fundamentals, Technology, Applications, 2003;4:987–1001.

3. [3] Kreuer K.-D., Paddison S.J., Spohr E., Schuster M. Transport in proton conductors for fuel-cell applications: Simulations, elementary reactions, and phenomenology. Chemical Reviews, 2004;104(10):4637–4678.

4. [4] Yugami H., Kubota K., Iguchi F., Tanaka Sh., Sata N., Esashi M. Micro solid oxide fuel cells with perovskite-type proton conductive electrolytes. Journal of chemical engineering of Japan: PowerMEMS 2010. Leuven, Belgium. December 1–3, 2010, 2010:199–202.

5. [5] Iwahara H. Proton conducting ceramics and their application. Solid State Ionics, 1996;86–88:9–15.

6. [6] Zhang Y., Knibbe R., Sunarso J., Zhong Y., Zhou W., Shao Z., Zhu Z. Recent progress on advanced materials for solid-oxide fuel cells operating below 500 °C. Advanced Materials, 2017;29(48):1–33.

7. [7] Panthi D., Tsutsumi A. A novel multistep dip-coating method for the fabrication of anode-supported microtubular solid oxide fuel cells. Journal of Solid State Electrochemistry,2014; 18(7):1899–1905.

8. [8] Shim J.H., Park J.S., An J., Gür T.M., Kang S., Prinz F.B. Intermediate temperature ceramic fuel cells with thin film yttrium-doped barium zirconate electrolytes. Chemistry of Materials, 2009;21:3290–3296.

9. [9] Dunyushkina L.A. Introduction to methods for producing film electrolytes for solid oxide fuel cells: monograph (Vvedenie v metody polucheniya plenochnykh elektrolitov dlya tverdooksidnykh toplivnykh elementov), Ekaterinburg: UrO RAN, 2015 (in Russ).

10. [10] Wachsman E.D. Lowering the temperature of solid oxide fuel cells. Science, 2011;334:935–939.

11. [11] Nandasiri M. I., Thevuthasan S. State-of-the-art thin film electrolytes for solid oxide fuel cells. Thin film structures in energy applications, Springer International Publishing, 2015:167–214.

12. [12] Zhang Y., Gao J., Meng G., Liu X. Production of dense yttria-stabilized zirconia thin films by dip-coating for IT-SOFC application. Journal of Applied Electrochemistry, 2004;34(6):637–641.

13. [13] Lybye D. Conductivity of A- and B-site doped LaAlO3, LaGaO3, LaScO3 and LaInO3 perovskites. Solid State Ionics, 2000;128:91–103.

14. [14] Lybye D., Bonanos N. Proton and oxide ion conductivity of doped LaScO3. Solid State Ionics, 1999;125:339–344.

15. [15] Nomura K., Takeuchi T., Kageyama H., Miyazaki Y. High temperature crystallographic study of (La0.9Sr0.1)MO3-α (M=Sc, In, and Lu) perovskite proton conductor. Solid State Ionics, 2003;162–163:99–104.

16. [16] Fujii Н., Katayama Y., Shimura T., Iwahara H. Protonic Conduction in perovskite-type Oxide Ceramics Based on LnScO3 (Ln=La, Nd, Sm or Gd) at High Temperature. Journal of Electroceramics, 1998;2(2):119–125.

17. [17] Stroeva A.Yu., Gorelov V.P., Kuzmin A.V., Vykhodets V.B., Kurennykh T.E. Effect of scandium sublattice defectiveness on ion and hole transfer in LaScO3-based proton-conducting oxides (Vliyanie defektnosti podreshetki skandiya na ionnyi i dyrochnyi perenos v protonprovodyashchikh oksidakh na osnove LaScO3). Russian Journal of Electrochemistry, 2011;47(3):264–274 (in Russ.).

18. [18] Stroeva A.Yu., Gorelov V.P., Kuzmin A.V., Antonova E.P., Plaksin S.V. Phase composition and conductivity of Lа1-хSrхScO3-а (x = 0.01÷0.20) under oxidative conditions (Fazovyi sostav i elektroprovodnost' Lа1-хSrхScO3-а (x = 0,01÷0,20) v okislitel'nykh usloviyakh). Russian Journal of Electrochemistry, 2012;48(5):509–517 (in Russ.).

19. [19] Stroeva A.Yu., Gorelov V.P. Nature of conductivity of perovskites Lа1-хSrхScO3-а (x = 0.01÷0.15) under oxidative and reducing conditions (Priroda provodimosti v perovskitah Lа1-хSrхScO3-а (x=0.01÷0.15) v okislitel'nyh i vosstanovitel'nyh uslovijah). Russian Journal of Electrochemistry, 2012;48(11):1079–1085 (in Russ.).

20. [20] Gorelov V.P., Stroeva A.Yu. Solid proton conducting electrolytes based on LaScO3 (Protonnye tverdye elektrolity na osnove LaScO3). Russian Journal of Electrochemistry, 2012;48(10):949–960 (in Russ.).

21. [21] Antipov E.V., Istomin S.Y. Cathode materials based on perovskite-like transition metal oxides for medium-temperature solid oxide fuel cells (Katodnye materialy na osnove perovskitoprdobnykh oksidov perekhodnykh metallov dlya srednetemperaturnykh tverdooksdnykh toplivnykh elementov). Uspekhi khimii, 2013;82(7):686–700 (in Russ.).

22. [22] Sun C., Hui R., Roller J. Cathode materials for solid oxide fuel cells: a review. Journal of Solid State Electrochemistry, 2010;14:1125–1144.

23. [23] Huang K., Feng M., Goodenough J.B., Schmerling M. Characterization of Sr-doped LaMnO3 and LaCoO3 as cathode materials for a doped LaGaO3 ceramic fuel cell. Journal of the Electrochemical Society, 1996;143(11):3630–3636.

24. [24] Beresnev S.M., Bobrenok O.F., Kuzin B.L., Bogdanovich N.M., Kurteeva A.A., Osinkin D.A., Vdovin G.K., Bronin D.I. Single fuel cell with supported LSM cathode (Edinichnaja toplivnaja jachejka s nesushhim LSM-katodom). Russian Journal of Electro-chemistry, 2012;48(10):969–975 (in Russ.).

25. [25] Stevenson J.W., Armstrong T.R., Pederson L.R., Li J., Lewinsohn C.A., Baskaran S. Effect of A-site cation nonstoichiometry on the properties of doped lanthanum gallate. Solid State Ionics, 1998;113–115:571–583.

26. [26] Kurteeva A.A., Bogdanovich N.M., Bronin D.I., Porotnikova N.M., Vdovin G.K., Pankratov A.A., Beresnev S.M., Kuzmina L.A. Options for adjustment of microstructure and conductivity of cathodic substrates of La(Sr)MnO3 (Vozmozhnosti regulirovanija mikrostruktury i jelektroprovodnosti nesushhih katodnyh podlozhek iz La(Sr)MnO3). Russian Journal of Electro-chemistry, 2010;46(7):811–819 (in Russ.).

27. [27] Dunyushkina L.A., Smirnov S.V., Plaksin S.V., Kuimov V.M., Gorelov V.P. A аcross-plane conductivity and microstructure of SrZr0.95Y0.05O3-d thin films. Ionics, 2013;19(12):1715–1722.

28. [28] Patent №2570509 RF, MPK 51 H 01 M 8/10. Method for obtaining a thin-film solid electrolyte for electrochemical devices (Sposob polucheniya tonkoplenochnogo tverdogo elektrolita dlya elektrokhimicheskikh ustroistv) / Gorelov V.P., Kuz'min A.V., Stroeva A.Yu., Dunyushkina L.A., Plekhanov M.S. ; zayavitel' i patentoobladatel' IVTE UrO RAN. – 2014148004/07 ; zayavl. 27.11.2014; opubl. 10.08.2015 (in Russ.).

29. [29] Kim S.W., Lee Y., Choi G.M. Electrical conductivity of Gd-doped ceria film at low temperatures (300– 500°C). Solid State Ionics, 2014;262:411–415.

30. [30] Stroeva A.Yu., Gorelov V.P., Kuzmin A.V., Ponomareva V.G., Petrov S.A. Effect of Iron Oxide on the Properties of La0.9Sr0.1ScO3-α protonics. Physics of the Solid State, 2015;57(7):1334–1341.