Influence of La/Pr Ratio on the Ageing Properties of La2-XPrxNiO4+δ as Cathodes in IT-SOFCs
Herein, the chemical stability of the nickelates under air at operating temperatures as well as the evolution of the polarization resistances during ageing (recorded under air at idc = 0 and idc ≠ 0 conditions) were studied for duration up to one month. La2NiO4+δ is chemically stable whereas Pr2NiO4+δ dissociates after 1 month at 600, 700 and 800 °C. At idc = 0 condition, the ageing of the half cells during 1 month under air shows no change in Rp, despite their various degrees of chemical stability. A different behavior is observed under idc ≠ 0 conditions with a large increase in Rp for Pr-rich phases in SOFC mode while interestingly, Rp remain stable in SOEC mode. In this presentation, the electrochemical properties of La2-xPrxNiO4+δ under ageing and postmortem analysis will be discussed in details.