Development of glass sealants for proton conducting ceramic cells: materials, concepts and challenges

Abstract In this study, we have successfully developed and tested sealing concepts for symmetrical, planar proton-conducting ceramic cells (PCCCs). Three glass sealants from the field of solid oxide cells were investigated as potential compatible sealing materials for PCCCs. The most promising results were obtained with a SiO 2 -MgO-CaO-Na 2 O-Al 2 O 3 -ZrO 2 -B 2 O 3 glass, which provided a dense, crack-free sealant between the proton-conducting ceramic cells and the Al 2 O 3 -coated ferritic steels. During the sealing process, a reaction layer between the interface of the BaCe 0.2 Zr 0.7 Y 0.1 O 3-δ contained in the PCCCs and the glass–ceramic, occurred. Here, we propose a reaction mechanism for this interaction and discuss its impact on potential applications. Moreover, next to evaluating potential glass sealants, we have successfully designed and demonstrated a new sealing geometry that prevents a potential gas crossover in the symmetrical proton-conducting ceramic cell.