Electrochemical properties and stability of Pr ₂ NiO ₄ -based electrodes suitable for solid oxide electrochemical cells with reduced operating temperatures

The objective of the study is to develop high-performance electrodes for electrochemical devices operating in the intermediate temperature range. In the first part of the study, the phase stability of a series of Pr2NiO4-based materials is investigated at a relatively high temperature (850 °C) to identify optimal candidates for further application in the electrodes operating in contact with a Sm-doped ceria electrolyte. The most promising compositions are fabricated into electrodes and subjected to 1100 h of accelerated electrochemical testing under ambient/wet air with thermal cycling every 100 h. In the second part of the study, the selected Ca/Cu substituted Pr2NiO4 electrodes are structurally optimized and then modified with PrOx to further enhance performance and achieve a target polarization resistance of less than 1 Ω cm2 at 600 °C – a benchmark for intermediate-to-low-temperature SOFCs. The performance stability of the infiltrated electrodes is subsequently assessed via a 500-hour electrochemical test at 700 °C, identifying the most robust electrode configuration.