Strength and hydrothermal stability of NiO–stabilized zirconia solid oxide cells fuel electrode supports

Long-term, reliable operation of Solid Oxide fuel and electrolysis Cell (SOCs) necessitates cells with high strength and resistance to mechanical degradation. In this work, strength, Young’s modulus and Low-Temperature Degradation (LTD) of several zirconia-based SOCs supports are studied. The study shows that replacing 3YSZ with a tetragonal zirconia compound having lower stabilizer contents can improve the strength of porous supports. An enhancement up to 30 % over the-state-of-the-art support (NiO‒3YSZ) can be achieved for example with using NiO‒2.5YSZ. It is further evidenced that tetragonal zirconia-based SOC components (both Y-doped and Ce-Y co-doped) are susceptible to LTD in the studied range of grain sizes (i.e. ≈ 200−300 nm). Addition of small amount of alumina (0.5 wt%) is observed to increase the LTD resistance of porous supports. The susceptibility to LTD must be considered in designing materials for SOCs, also during materials processing, storage, handling and operation where a dry atmosphere is recommended.