Reversible operation of microtubular solid oxide cells using La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.9Gd0.1O2-δ oxygen electrodes

Abstract

Yttria stabilized zirconia (YSZ) based microtubular solid oxide fuel cells (mT-SOFCs) using La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) and Ce 0.9 Gd 0.1 O 2-δ (GDC) as the oxygen electrode, along with a porous GDC electrolyte-electrode barrier layer, were fabricated and characterized in both fuel cell (SOFC) and electrolysis (SOEC) operation modes. The cells were anode-supported, the NiO-YSZ microtubular supports being made by Powder Extrusion Moulding (PEM). The cells showed power densities of 695 mW•cm-2 at 800 °C and 0.7 V in SOFC mode, and of 845 mA•cm-2 at 800 °C and 1.3 V in SOEC mode. AC impedance experiments performed under different potential loads demonstrated the reversibility of the cells. These results showed that these cells, prepared with a method suitable for using on an industrial scale, are highly reproducible and reliable, as well as very competitive as reversible SOFC-SOEC devices operating at intermediate temperatures.

Direct Electrolysis of CO2 in a Symmetrical Solid Oxide Electrolysis Cell with Spinel MnCo2O4 as Electrode

“…There are DRT characteristic peaks appearing at around 3~5 Hz and 50~160 Hz in Figure 5c for EIS under OCV. [34,35] There are also two electrochemical processes occurring at around 2~10 Hz and 80~1600 Hz. The change of area indicates that both interfacial polarization resistance (R ct ) and concentration polarization resistance (R gd ) decrease as the temperature increases.…”

“…The more obvious differences in higher frequency suggest that the charge transfer mechanism plays a more important role than the gas mass transfer with temperature increasing from 750 to 850°C. [34,35] There are also two electrochemical processes occurring at around 2~10 Hz and 80~1600 Hz. Compared with the plots under OCV, the area in high frequency decreases more sharply than that in low frequency at 0.2 A cm À 2 , which indicates a more obvious promotion of charge transfer.…”

Development of novel air electrode materials for the SOFC and SOEC technologies

“…LSCF is more stable and its degradation rate in the case of SOFC is between 0.6-1.4% per 1000 h and for SOEC stack is 5.6% per 1000 h after 4000 h of operation [42][43][44]. Recently, López-Robledo et al presented performance of the LSCF-Ce0.9Gd0.1O2-δ composite in the reversible mode, for which they obtained the highest current densities 0.845 A cm -2 at 1.3 V (800 °C) for microtubular electrolyzer [45]. BSCF, commonly applied in the SOFC stacks, shows low polarization resistance, but its stability in the SOEC conditions is significantly lower compared to the LSC and LSCF [38].…”

High performance nanostructured bismuth oxide–cobaltite as a durable oxygen electrode for reversible solid oxide cells

“…[53][54][55] The electrolysis performance of the cell with the ESB-SmCPd electrode is comparable or even superior to that of the cells with other oxygen electrodes, such as mixed LSM-YSZ composites, 56,57 LSM inltrated YSZ, 58 co-synthesized YSB-LSM, 32 and LSCF-GDC composites. 59 The long-term operating stability of the cell in the fuel cell mode was measured at 0.5 A cm À2 and 750 C (Cell-#3) as well as at 0.25 A cm À2 and 600 C (Cell-#1), and the results are shown in Fig. 5.…”