A novel Ag based sealant for solid oxide cells with a fully tunable thermal expansion

JOURNAL OF ALLOYS AND COMPOUNDS

卷:831

Article

Si, Xiaoqing^1,2  Cao, Jian¹  Talic, Belma²  Ritucci, Ilaria²  Li, Chun¹  Qi, Junlei¹  Feng, Jicai¹  Kiebach, Ragnar² 

[1] Harbin Inst Technol, State Key Lab Adv Welding & Joining, Harbin 150001, Peoples R China

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

关键词: Reactive air brazing;    Solid oxide fuel cell;    Solid oxide electrolysis cell;    Sealant;    Thermal expansion coefficient;   

DOI  :  10.1016/j.jallcom.2020.154608

来源: Elsevier

【 摘 要 】

In this work, we show that a promising sealant for the use in solid oxide fuel cell and electrolysis stacks can be obtained by combing a conventional silver-based braze with eucryptite (LiAlSiO4), a negative thermal expansion coefficient material. The thermo-mechanical properties of the Ag2CuO-LiAlSiO4 system and the microstructure as a function of the LiAlSiO4 content are investigated. By adding 8 wt% of the LiAlSiO4 filler, the coefficient of thermal expansion of the Ag2CuO braze is lowered from 19.6 x 10(-6) K-1 to 12.2 x 10(-6) K-1 (25-800 degrees C). The aluminized Crofer 22 H is brazed to the gadolinium-dope ceria electrolyte of the solid oxide cell by employing the composite braze. The obtained joints are defect free and display low leak rates (1.2-1.4 x 10(-3) sccm cm(-1)). The leak rate and structural integrity of the joints are retained after aging tests at 800 degrees C for 300 h, indicating excellent stability of the sealant. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free