Boosting solid oxide electrolyzer performance by fine tuning the microstructure of electrodes - Preliminary study

This paper addresses the concept of adjusting the microstructure of the supports of solid oxide electrolyzers in order to boost performance. While several earlier studies focused on maximizing performance, reducing degradation, adjusting operating conditions and introducing new materials or designs of electrolysis stack, the current study addresses potential improvement of the cell by fine tuning the microstructure without any major redesign of existing cells. In the proposed approach, the study combined numerical sim-ulations with definition of the model, which can aid in predicting the performance of a cell with adjusted porosity of the electrode support, and preparation of modified cells with alternative pore forming agents and two alternative sintering temperature levels. Supports of solid oxide cells were sintered at 1350 and 1400 & DEG;C with pore former content of 25-35%. This resulted in the porosity of supports being in the range of 47-54%. Cells with 10Sc1CeSZ and 8YSZ electrolytes were investigated in operando. The proposed approach makes it possible to quantitatively and qualitatively assess the potential gain when the reference cell is slightly modified, according to guidelines obtained from the model. It was found that the proposed method to fine tune the microstructure can result in improved performance, with a clear indication that adjusting the sintering tem-perature has a stronger effect on the microstructure of the support than increasing the pore forming agent. & COPY; 2022 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This paper discusses the concept of improving the performance of solid oxide electrolyzers by adjusting the microstructure of the support materials. Instead of major redesigns, this study proposes fine-tuning the microstructure to enhance cell performance. The results show that adjusting the sintering temperature has a greater impact on the support microstructure than increasing the pore-forming agent.