Effect of Gd-doped ceria infiltration into Ni-YSZ on reversible solid oxide cell operation

Gadolinium doped ceria (GDC) infiltration into Ni-(Y2O3)(0.08)(ZrO2)(0.92) (Ni-YSZ) fuel electrodes has been shown to significantly improve solid oxide electrolysis cell performance and stability. However, the effects of GDC infiltration on cells operated reversibly between fuel cell and electrolysis modes have not been reported previously. Here we present reversible solid oxide cell life test results for different GDC infiltration loadings into NiYSZ electrodes in two types of fuel-electrode-supported solid oxide cells. Electrochemical impedance spectroscopy reveals that GDC infiltrant lowers the initial cell area specific resistance (ASR) and limits the degradation - for example, the GDC-infiltrated electrode ASR increased by 0.1 Omega cm(2) over 1000 h of reversible operation at +/- 0.5 A cm(-2) and 800 degrees C, compared to 0.19 Omega cm(2) for non-infiltrated cells. Cell voltage degradation rates were reduced by infiltration during operation at a current density of +/- 0.5 A cm(-2) at 800 degrees C, and during at 700 degrees C at +/- 0.75 A cm(-2) . Scanning electron microscopy observations show that the infiltrated GDC nanoparticles mitigate Ni particle coarsening in the Ni-YSZ electrode, possibly explaining the enhanced cell stability.

Automated summary

Infiltration of gadolinium doped ceria (GDC) has been shown to significantly improve the performance and stability of solid oxide electrolysis cells. It reduces the initial cell resistance and limits degradation, resulting in enhanced cell stability. The infiltrated GDC nanoparticles mitigate Ni particle coarsening in the Ni-YSZ electrode, further contributing to improved cell performance.