Synthesis and electrochemical properties of Sr3Fe1.8Co0.2O7 as a solid oxide fuel cell cathode

Document Type : Research Paper

Authors

1 Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran

2 Department of Materials Science & Eng., Sharif University of , Tehran, Iran

3 Renewable Energy Department, Niroo Research Institute, Tehran, Iran

Abstract

Solid oxide fuel cells (SOFCs) have attracted a lot of attention for their high efficiency, fuel flexibility, lower air pollution, etc. Unfortunately, their operating high temperature is the main shortcoming for commercialization. One of the main hurdles to achieving intermediate temperature SOFCs is the conductivity of their cathode materials at lower temperatures.Therefore, in this study, a conductive Sr_3 Fe_1.8 Co_0.2 O_7 cathode material with a Ruddlesden−Popper crystal structure was first successfully synthesized and then the effect of sintering temperature was investigated. X-ray diffraction analysis results revealed that the powder was approximately pure. Moreover, field emission scanning electron microscope (FESEM) micrographs rod-shaped particles with an average particle size of 670 nm. To evaluate the sintering effect on the electrochemical behavior of the synthesized powder, a paste of the powder was painted on both sides of the Gadolinium doped Ceria (CGO) electrolyte and sintered at 1000°C and 1100°C. The electrochemical impedance analysis on symmetrical half-cells revealed that the minimum polarization resistance for the sintered cathode at 1000°C and 1100°C was  1.1 Ω.〖cm〗^2 and 1.6 Ω.〖cm〗^2 at 800֯C. The FESEM micrograph showed High-temperature sintering could affect the interface between CGO and SFCO and decrease transport pathways for oxygen ions conduction at higher sintering temperatures. Also, the electrical conductivity of the sample was determined by the four-point probe electrical conductivity method in the temperature range of 200_800˚C at room atmosphere. The results show that the maximum electrical conductivity at 427°C is 76 S.〖cm〗^(-1).

Keywords

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References

  1. [1]. Jacobson, A.J., Materials for solid oxide fuel cells. Chemistry of Materials, 2010. 22(3): p. 660-674.

    [2]. Steele, B.C. and A. Heinzel, Materials for fuel-cell technologies, in Materials For Sustainable Energy: A Collection of Peer-Reviewed Research and Review Articles from Nature Publishing Group. 2011, World Scientific. p.224-231.

    [3]. Yamamoto, O., Solid oxide fuel cells: fundamental aspects and prospects. Electrochimica Acta, 2000. 45(15-16): p. 2423-2435.

    [4]. Sun, C., R. Hui, and J. Roller, Cathode materials for solid oxide fuel cells: a review. Journal of Solid State Electrochemistry, 2010. 14(7): p. 1125-1144.

    [5]. Manthiram, A., et al., Crystal chemistry and properties of mixed ionic-electronic conductors. Journal of electroceramics, 2011. 27(2): p. 93-107.

    [6]. Kilner, J.A. and M. Burriel, Materials for intermediate-temperature solid-oxide fuel cells. Annual Review of Materials Research, 2014. 44: p. 365-393.

    [7]. Huan, D., et al., High-performanced cathode with a two-layered R–P structure for intermediate temperature

    solid oxide fuel cells. ACS Applied Materials & Interfaces, 2016. 8(7): p. 4592-4599.

    [8]. Torabi, M., et al., Experimental investigation of a solid oxide fuel cell stack using direct reforming natural gas. Iranian Journal of Hydrogen & Fuel Cell, 2017. 4(4): p. 301-306.

    [9]. Ghorbani-Moghadam, T., et al., Characterization, Electrical and Electrochemical Study of La 0.9 Sr 1.1 Co 1− x Mo x O 4 (x≤ 0.1) as Cathode for Solid Oxide Fuel Cells. Journal of Electronic Materials, 2020. 49(11): p. 6448-6454.

    [10]. Armstrong, T., F. Prado, and A. Manthiram, Synthesis, crystal chemistry, and oxygen permeation properties of

    LaSr3Fe3− xCoxO10 (0≤ x≤ 1.5). Solid state ionics, 2001. 140(1-2): p. 89-96.

    [11]. Woolley, R.J. and S.J. Skinner, Novel La2NiO4+ δ and La4Ni3O10− δ composites for solid oxide fuel cell

    cathodes. Journal of power sources, 2013. 243: p. 790-795.

    [12]. Kim, J.-H. and A. Manthiram, Characterization of Sr2. 7Ln0. 3Fe1. 4Co0. 6O7 (Ln= La, Nd, Sm, Gd) intergrowth

    oxides as cathodes for solid oxide fuel cells. Solid State Ionics, 2009. 180(28-31): p. 1478-1483.

    [13]. Kim, J.-H., et al., Crystal chemistry and electrochem ical properties of Ln (Sr, Ca) 3 (Fe, Co) 3 O 10 intergrowth

    oxide cathodes for solid oxide fuel cells. Journal of Materials Chemistry, 2011. 21(8): p. 2482-2488.

    [14]. Kim, Y. and A. Manthiram, Electrochemical properties of Ln (Sr, Ca) 3 (Fe, Co) 3O10+ Gd0. 2Ce0. 8O1. 9

    composite cathodes for solid oxide fuel cells. Journal of The Electrochemical Society, 2011. 158(10): p. B1206.

    [15]. Lee, K. and A. Manthiram, LaSr3Fe3-y Co y O10-δ (0≤ y≤ 1.5) Intergrowth Oxide Cathodes for Intermediate

    Temperature Solid Oxide Fuel Cells. Chemistry of materials, 2006. 18(6): p. 1621-1626.

    [16]. Manthiram, A., F. Prado, and T. Armstrong, Oxygen separation membranes based on intergrowth structures.

    Solid State Ionics, 2002. 152: p. 647-655.

    [17]. Markov, A.A., et al., Oxygen nonstoichiometry and ionic conductivity of Sr3Fe2-x Sc x O7-δ. Chemistry of

    materials, 2007. 19(16): p. 3980-3987.

    [18]. Mohebbi, H., et al., The Effect of Process Parameters on the Apparent Defects of Tape-Cast SOFC Half-Cell.

    1. 5(4): p. 12-16.

    [19]. Huan, D., et al., High-performanced cathode with a two-layered R–P structure for intermediate temperature solid oxide fuel cells. 2016. 8(7): p. 4592-4599.

    [20]. Padmasree, K.P., et al., Electrochemical properties of Sr2.7-xCaxLn0.3Fe2-yCoyO7-δ cathode for intermediate-

    temperature solid oxide fuel cells. International Journal of Hydrogen Energy, 2019. 44(3): p. 1896-1904.

    [21]. Kuo, J., H.U. Anderson, and D.M.J.J.o.S.S.C. Sparlin, Oxidation-reduction behavior of undoped and Sr-doped

    LaMnO3 nonstoichiometry and defect structure. 1989. 83(1): p. 52-60.

    [22]. Zhou, Q., et al., Novel cobalt-free cathode material (Nd0. 9La0. 1) 2 (Ni0. 74Cu0. 21Al0. 05) O4+ δ for intermediate-temperature solid oxide fuel cells. 2015. 41(1): p.639-643.

    [23]. Zhao, Y., et al., Performance and distribution of relaxation times analysis of Ruddlesden-Popper oxide Sr3Fe1.

    3Co0. 2Mo0. 5O7-δ as a potential cathode for protonic solid oxide fuel cells. 2020. 352: p. 136444.

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