Copper Doped La_0.8Sr_1.2FeO₄ Ruddlesden‐Popper SOFC Cathode: Synthesis, Characterization and Model Analysis

Abstract

Novel La0.8Sr1.2Fe0.9Cu0.1O4±δ (LSFC) oxides for application as cathodes in SOFCs were prepared with two different synthetic methods: solid‐state‐reaction (SSR) and molten citrate (MC). The XRD, ICP‐OES, SEM, laser granulometry and TG‐DTA techniques were applied for the physico‐chemical characterization. 4‐points DC conductivity measurements and EIS experiments were performed in the electrochemical characterization. Compared to SSR, the MC method allowed to obtain finer powders (∼2 μm vs. ∼5 μm) and required lower calcination temperatures (1,000 °C vs. 1,400 °C). The SSR and MC samples showed similar conductivity (30 S cm−1 at 700 °C) and polarization resistance (1.7 Ω cm2 at 700 °C). The EIS results were analyzed with the equivalent circuits method, and with a physically‐based model for the simulation of the impedance spectra, which indicated that the oxygen reduction mechanism involved the TPB. The MC method revealed preferential, thanks to the lower calcination temperature.

Anode‐supported solid oxide fuel cells with multilayer LSC/CGO/LSC cathode

“…Therefore, La 1−x Sr x CoO 3 (LSC)-and La x Sr 1-x Co y Fe 1-y O 3-d (LSCF)based systems are the most promising [11,18]. There are however alternative perovskite-type cathode materials, such as Sm 0.7 Sr 0.3 Co 3 [19], BaCo 0.7 Fe 0.2 Nb 0.1 O 3 [20], cobalt free (Nd 0.9 La 0.1 ) 1.6 Sr 0.4 Ni 0.75 Cu 0.25 O 3.8 [21], La 0.8 Sr 1.2 Fe 0.9 Cu 0.1 O 4 [22], and BaFe 1−x Cu x O 3 [23].…”

Interfacial energy barrier: A crucial factor affecting cathodic polarization resistance of solid oxide fuel cells

“…For instance, the ASR value of NBCFM with the LSGM electrolyte was only 0.166 Ω cm 2 , and it was lower by 52% than the value obtained with the GDC electrolyte. As shown in Figure 3B, the ASR values of NBCFM with the LSGM electrolyte are considerably lower than those obtained for Ruddlesden‐Popper La 2 NiO 4+δ 25 and La 0.8 Sr 1.2 Fe 0.9 Cu 0.1 O 4+δ , 26 double perovskite GdBaCuCo 0.5 Fe 0.5 O 5+δ , 27 and SmBaCoCuO 5+δ. 28 In addition, these values were comparable to or even lower than those obtained for the perovskites La 0.5 Sr 0.5 Fe 0.8 Cu 0.2 O 3−δ 29 and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (Figure S4).…”

“…(A) Nyquist plots of the two symmetric cells at 700°C. (B) ASR values of La 2 NiO 4+δ , 25 La 0.8 Sr 1.2 Fe 0.9 Cu 0.1 O 4+δ , 26 GdBaCuCo 0.5 Fe 0.5 O 5+δ , 27 SmBaCoCuO 5+δ , 28 La 0.5 Sr 0.5 Fe 0.8 Cu 0.2 O 3−δ , 29 La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ , and NBCFM. DRT curves of NBCFM‐based symmetric cells with (C) GDC and (D) LSGM electrolytes.…”