Design of a functional steam electrode for Proton-conducting ceramic electrolysis cells based on BaCo0.4Fe0.4Zr0.2O3−δ : BaZr0.7Ce0.2Y0.1O3−δ composite

Abstract

A key issue in the steam electrode development for Proton-conducting Ceramic Electrolysis Cells (PCECs) is the required contact with the electrolyte material as well as thermo-chemical compatibility during cell processing and operation. This study focuses on BaCo_0.4Fe_0.4Zr_0.2O${}_{3-\delta }$ (BCFZ442) as a potential steam electrode material paired with the state-of-the-art proton conductor BaZr_0.7Ce_0.2Y_0.1O${}_{3-\delta }$ (BZCY721). The objectives are to identify an optimal material composition amongst several compositional variations and to define its corresponding fabrication conditions for achieving suitable electrodes compatibility, adhesion and performance for further translation into the cell fabrication process. Therefore, we tested 90:10, 70:30 and 50:50 BCFZ442:BZCY721 composites which were heat-treated in the temperature of 800–1200 °C. The phase evolution accompanied by thermal and microstructural analyses and in addition to electrical and mechanical characterization yielded interesting results. Extensive analysis indicate compositional, functional and fabrication optimum in the steam electrode development of PCECs.