Nickel/10 mol% scandia - 1 mol% yttria stabilised zirconia (10Sc1YSZ) fuel electrodes for solid oxide electrolysis cells

Degradation of the fuel electrode remains a key challenge to solve for a wider adoption of solid oxide electrolysis cell (SOEC) technology to produce green H 2 . In this context, alternatives to the nickel (Ni)/8 mol% yttria stabilised zirconia (8YSZ) fuel electrode, less prone to Ni migration, are being sought. In this work, 10 mol% scandia-1 mol% yttria stabilised zirconia (10Sc1YSZ) is investigated as such an alternative. 10Sc1YSZ-based cells were fabricated by tape casting, screen printing and low temperature sintering. Improvements in durability are observed compared to the state-of-the-art Ni/8YSZ-based cells, which is found to correlate with absent Ni migration. A voltage degradation rate of 2 %/kh is measured at 750 °C and −0.75 A/cm 2 . Recovery of lost cell performance at −1.0 A/cm 2 is found through idling the cell under open circuit conditions, indicating reversibility of fuel electrode degradation. Multi-physics impedance modelling is used to analyse changes in microstructural parameters. The phase stability of 10Sc1YSZ and reduction conditions of the electrodes are investigated, showing an impact on the cell durability. The Ni/10Sc1YSZ fuel electrodes, requiring only minor modifications to the state-of-the-art Ni/yttria stabilised zirconia electrodes, demonstrate improved durability and suppressed Ni migration.