Pd–La0.6Sr0.4Co0.2Fe0.8O3– composite as active and stable oxygen electrode for reversible solid oxide cells

Abstract

To promote the electrocatalytic activity and stability of traditional La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3– δ (LSCF) oxygen electrodes in reversible solid oxide cells (RSOCs), conventional physical mixed method was used to prepare the Pd-LSCF composite oxygen electrode. The cell with Pd-LSCF|GDC|YSZ|Ni-YSZ configuration shows perfect electrochemical performance in both solid oxide fuel cell (SOFC) mode and solid oxide electrolysis cell (SOEC) mode. In the SOFC mode, the cell achieves a power density of 1.73 W/cm 2 at 800 °C, higher than that of the LSCF oxygen electrode with 1.38 W/cm 2 . In the SOEC mode, the current density at 1.5 V is 1.67 A/cm 2 at 800 °C under 50 vol% steam concentration. Moreover, the reversibility and stability of the RSOCs is tested during 192 h long-term reversible operation. The degradation rate of the cell is only 2.2%/100 h and 2.5%/100 h in the SOEC and the SOFC mode, respectively. These results confirm that compositing Pd with the LSCF oxygen electrode can considerably boost the electrochemical performance of LSCF electrode in RSOCs field. The cell with configuration of Pd-LSCF|GDC|YSZ|Ni-YSZ shows well performance in RSOCs mode. In the SOFC mode, it can reach a maximum power density of 1.73 W/cm 2 at 800 °C; In the SOEC mode, the current density at 1.5 V can achieve 1.67 A/cm 2 at 800 °C with 50 vol% H 2 O. In addition, the cell also shows well reversibility and stability during 192 h long-term test. • Pd-La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3– δ .|GDC|YSZ|Ni-YSZ cell was tested as reversible solid oxide cells (RSOCs). • In the SOFC mode, the cell achieves a higher power density of 1.73 W/cm 2 at 800 °C. • In the SOEC mode, the current density achieves 1.67 A/cm 2 at 800 °C with 50 vol% steam concentration at 1.5V. • The cell shows superior reversibility and stability during 192 h long-term test.