Investigation of thin perovskite layers between cathode and doped ceria used as buffer layer in solid oxide fuel cells

Abstract

Porous and about 40-μm-thick LNF cathodes were deposited on both sides of the substrate and sintered at 1100°C. Different thicknesses of the thin perovskite layer were investigated in order to find the most effective one and to better understand its influence on the cathode/electrolyte interface. It was found that approximately 150 nm LNF or LSCF layer is sufficient to minimize interface resistance and improve cathode reproducibility. It was concluded that the thin perovskite layer increases contact area and improves the oxygen ion transport between the cathode and electrolyte without influencing the oxygen reduction reaction mechanism.

Nanocrystalline cathode functional layer for SOFC

“…When the layer was annealed at 1200 °C and its grains were completely separated from each other, the impedance spectrum of the cathode became similar to the reference. Small deviations may be a result of inter-diffusion between the LSCF and CGO, which can occur at 1200 °C [22,23] or slightly altered sintering of the cathode/electrolyte interface, which can improve cathode preparation repeatability [11]. Figure 8 shows the ADIS plots of the impedance spectra shown in Figure 7, calculated in relation to the reference sample (without the LSCF thin layer).…”

“…Our previous study has shown that the optimum thickness of the functional layer should be around 120-150 nm for both symmetrical cells [11] and fuel cells [12]. The improvement in polarization resistance was obtained by using an electrode with dominating electronic conductivity (LaNi 0.6 Fe 0.4 O 3-δ , LNF) and for the cathode with mixed conducting LSCF as a thin cathode layer.…”

Improvement of Oxygen Electrode Performance of Intermediate Temperature Solid Oxide Cells by Spray Pyrolysis Deposited Active Layers

“…Chrzan et al. [ 21,22 ] investigate different perovskite layers such as La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 , LaNi 0.6 Fe 0.4 O 3 (LNF), and SrTi 0.65 Fe 0.35 O 3 produced by spin‐coating method. Molin et al.…”

“…Modification of the oxygen electrode interface was also developed in our research group. Chrzan et al [21,22] investigate different perovskite layers such as La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 , LaNi 0.6 Fe 0.4 O 3 (LNF), Intermediate temperature solid oxide fuel cells oxygen electrodes are modified by active interfacial layers. Spray pyrolysis is used to produce thin (≈500 nm) layers of mixed ionic and electronic conductors: Sm 0.5 Sr 0.5 CoO 3−δ (SSC), La 0.6 Sr 0.4 CoO 3−δ (LSC), La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (LSCF), and Pr 6 O 11 (PrO x ) on the electrode-electrolyte interface.…”

Effect of sintering temperature on electrochemical performance of porous SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) oxygen electrodes for solid oxide cells

“…Because of their Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10008-020-04534-0) contains supplementary material, which is available to authorized users. high ionic conductivity (~10 −2 S cm −1 at 800°C) [28], they have found application as oxygen separation membranes [29,30], catalysts for water electrolysis reactions [31], resistive sensors of oxygen [32] and ethanol [33], and also in solid oxide fuel cell (SOFC) systems as electrodes [34][35][36] or the functional layer [37]. STFx-based materials show low polarisation resistance and good long term stability, including limited Sr surface segregation [38,39], which is problematic for LSC/LSCF compounds.…”