An Ag based brazing system with a tunable thermal expansion for the use as sealant for solid oxide cells

JOURNAL OF POWER SOURCES

卷:315

Article

Kiebach, Ragnar¹  Engelbrecht, Kurt¹  Grahl-Madsen, Laila²  Sieborg, Bertil²  Chen, Ming¹  Hjelm, Johan¹  Norrman, Kion¹  Chatzichristodoulou, Christodoulos¹  Hendriksen, Peter Vang¹ 

[1] Tech Univ Denmark, Dept Energy Convers & Storage, Riso Campus,Frederiksborgvej 399, DK-4000 Roskilde, Denmark

[2] IRD Fuel Cell AS, Kullinggade 31, DK-5700 Svenborg, Denmark

关键词: Brazing;    Sealant;    Solid oxide fuel cell;    Solid oxide electrolysis cell;    Silver;    Corrosion;   

DOI  :  10.1016/j.jpowsour.2016.03.030

来源: Elsevier

【 摘 要 】

An Ag-Al2TiO5 composite braze was developed and successfully tested as seal for solid oxide cells. The thermo-mechanical properties of the Ag-Al2TiO5 system and the chemical compatibility between this composite braze and relevant materials used in stacks were characterized and the leak rates as a function of the operation temperature were measured. The thermal expansion coefficient in the Ag-Al2TiO5 system can be tailored by varying the amount of the ceramic filler. The brazing process can be carried out in air, the joining partners showed a good chemical stability and sufficient low leak rates were demonstrated. Furthermore, the long-term stability of the Ag-Al2TiO5 composite braze was studied under relevant SOFC and SOEC conditions. The stability of brazed Crofer/Ag-Al2TiO5/NiO-YSZ assemblies in reducing atmosphere and in pure oxygen was investigated over 500 h at 850 degrees C. Additionally, a cell component test was performed to investigate the durability of the Ag-Al2TiO5 seal when exposed to dual atmosphere. The seals performed well over 900 h under electrolysis operation conditions (-0.5 A cm(2), 850 degrees C), and no cell degradation related to the Ag-Al2TiO5 sealing was found, indicating that the developed braze system is applicable for the use in SOFC/SOEC stacks. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free