Stability of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 /Ce 0.9 Gd 0.1 O 2 cathodes during sintering and solid oxide fuel cell operation

Infiltration, Overpotential and Ageing Effects on Cathodes for Solid Oxide Fuel Cells: La0.6Sr0.4Co0.2Fe0.8O3-δversus Ba0.5Sr0.5Co0.8Fe0.2O3-δ

“…Moreover, the correlation between their redox behavior under electrochemical operating conditions is still unclear. Many studies have been devoted to investigating LSCF degradation and several causes have been reported, among them: i) mutual cations diffusion between interfaces with consequent atoms depletion and phase separation, [11][12][13][14][15][16] ii) LSCF grain coarsening, 17 iii) reactivity with YSZ-based electrolytes, even with ceria-based barrier layer, 18 iv) impurity contamination, namely Cr from metal interconnects and B from sealing when the cell is inside a stack.…”

“…Many studies have been devoted to investigating LSCF degradation and several causes have been reported, among them: i) mutual cations diffusion between interfaces with consequent atoms depletion and phase separation, [11][12][13][14][15][16] ii) LSCF grain coarsening, 17 iii) reactivity with YSZ-based electrolytes, even with ceria-based barrier layer, 18 iv) impurity contamination, namely Cr from metal interconnects and B from sealing when the cell is inside a stack. [19][20][21] Some recent work performed on an LSCF/CGO (Ce 0.9 Gd 0.1 O 2-δ ) composite cathode on a YSZ electrolyte with a CGO barrier layer 11 affirms that Sr depletion, phase separation and cations inter-diffusion occur mainly during the fabrication process, with negligible contributions during long-term operation (973 K). On the other hand, some previous works conversely found that LSCF cathode degradation also occurs during long-term testing, although that works was generally carried out at temperatures higher than the temperature investigated in this paper (973 K).…”

Microstructure and Polarization Studies on Interlayer Free La0.65Sr0.3Co0.2Fe0.8O3–δ Cathodes Fabricated on Yttria Stabilized Zirconia by Solution Precursor Plasma Spraying

“…Despite of the many favorable references about the stability of LSCF related compositions with YSZ electrolyte at the operating temperatures below 800°C [15,19,[21][22][23][24][25], in order to ascertain the reactivity of the specific composition under investigation, La 0.65 Sr 0. 3 Figure 6.…”

“…At elevated temperatures, optimized LSCF compositions are reported to exhibit electronic conductivities exceeding 10 2 S cm -1 [3] and reasonably good O 2ionic conductivity [4]. In order to avoid undesired reactions, doped ceria (for instance, Ce 0.8 Gd 0.2 O 2-d (GDC)) is commonly applied as an interlayer between YSZ and LSCF and significantly improved performance has been reported [16][17][18][19][20]. Many reports discussing the microstructure-surface area-performance correlation of LSCF cathodes fabricated mostly on doped ceria electrolytes can be seen in the literature [5][6][7][8].…”

“…LSCF with optimized composition and microstructure are reported to exhibit very low polarization resistance (R p ) val--ues, compatible thermal expansion coefficient with electrolyte and structural stability. If the formation of insulating phase during the fabrication step is avoided through the adoption of innovative techniques, its formation during the operation of fuel cells is less likely (at least up to 750°C) [19,21]. Electrodes with higher surface area and larger triple phase boundary (TPB) densities result in lower R p and higher performance.…”