Calcium–Borosilicate Glass-Ceramics as a Sealant for Solid Oxide Fuel Cells

• Published in: Russian journal of electrochemistry 2024-03, Vol.60 (3), p.216-222
• Main Authors: Zhigachev, A. O., Bredikhin, S. I., Agarkova, E. A., Matveev, D. V.
• Format: Article
• Language: English
• Subjects: Adhesion; Aluminosilicates; Aluminum silicates; Barium; Boron oxides; Borosilicate glass; Calcium; Chemical composition; Chemistry; Chemistry and Materials Science; Electrochemistry; Electrolytes; Electrolytic cells; Ferritic stainless steels; Glass ceramics; Overheating; Physical Chemistry; Sealants; Sealing; Sealing compounds; Silicon dioxide; Softening points; Solid oxide fuel cells; Zirconium dioxide
• ISSN: 1023-1935; 1608-3342
• DOI: 10.1134/S1023193524030121

The applicability of calcium–borosilicate glass-ceramics with high boron oxide content as a sealant for solid oxide fuel cells is studied. Chemical composition of the studied materials is: 33 mol % CaO, 21 mol % B 2 O 3 , and 46 mol % SiO 2 . The material is studied as an alternative to the existing calcium– and barium–aluminosilicate-based sealants because of the latters’ limited adhesion to steel interconnects in fuel cells. The studied sealant is shown to have a softening point of about 920–930°C, which allows using it for sealing of fuel cells at 925°C. Use of relatively low sealing temperature allows avoiding overheating of the cell during the sealing and avoiding the accompanying degradation of the battery operational characteristics. The studied sealant demonstrated excellent adhesion to the surface of interconnect materials (the Crofer 22 APU steel). Furthermore, the studied sealant is found to be thermomechanically compatible with the Crofer 22 APU steel and ZrO 2 -based electrolytes.