Accelerated degradation for solid oxide electrolysers: Analysis and prediction of performance for varying operating environments

Solid oxide electrolysis cells (SOECs) are an efficient technology for the production of green hydrogen, that has great potential to contribute to the energy transition and decarbonization of industry. To date, however, time- and resource-intensive experimental campaigns slow down the development and market penetration of the technology. In order to speed-up the evaluation of SOEC performance and durability, accelerated testing protocols are required. This work provides the results of experimental studies on the performance of a SOEC stack operated under accelerated degradation conditions. In order to initiate and accelerate degradation, experiments were performed with high steam partial pressures at the gas inlet, higher voltages and lower temperatures and high steam conversion rates. Thereby, different types and degrees of impact on performance were observed, which were analyzed in detail and linked to the underlying processes and degradation mechanisms. In this context, significantly higher degradation rates were found compared to operation under moderate operating conditions, with the different operating strategies varying in their degradation acceleration potential. The results also suggest that a few hundred hours of operation may be sufficient to predict long-term performance, with the proposed operating strategies providing a solid basis for accelerated assessment of SOEC performance evolution and lifetime.