Solid oxide fuel cells (SOFCs) are devices that can convert chemical energy to electricity directly with high efficiency and fuel flexibility. Here, we fabricate perovskite single crystal thin films as cathodes with the composition of Ba_0.95La _0.05FeO_3-δ (BLF) by pulsed laser deposition (PLD) on yttria-stabilized zirconia (YSZ) substrates. Sm-doped Ceria (SDC) is deposited between YSZ and perovskite thin films in this study as an interlayer. The phase structure, surface morphology and roughness of the BLF thin films are characterized by X-ray diffraction and atomic force microscopy. X-ray photoelectron spectroscopy is used to analyze the elemental composition and chemical state of the deposited thin film [1-2]. Electrochemical impedance spectra measurements obtained from the symmetric cells with the configuration of BLF /SDC/YSZ/SDC/ BLF reveal that polarization resistance of BLF (001) thin films (100 nm) is as low as ~0.1 Ω cm2 at 700 °C and 0.21 atm oxygen pressure. The polarization resistances of BLF are lower than those of other perovskite electrodes, e.g., La_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ. Furthermore, our computational results, including density functional theory and molecular dynamics simulations, show that the BLF is characterized by low vacancy formation energy and fast oxygen transport [3-4].

References: 

[1] D. Chen, C. Chen, F. Dong, Z. Shao, F. Ciucci, J. Power Sources, 250, 188-195 (2014)

[2] C. Chen, D. Chen, Y. Gao, Z. Shao, & F. Ciucci. J. Materials Chemistry A, 2, 14154-14163 (2014) 

[3] Z.M. Baiyee, C. Chen, & F. Ciucci. Physical Chemistry Chemical Physics, 17, 23511-23520 (2015)

[4] C. Chen, Z.M. Baiyee, & F. Ciucci. Physical Chemistry Chemical Physics, 17, 24011-24019 (2015)