PNNL

Abstract

One of the critical issues in designing and fabricating high performance planar solid oxide fuel cell (pSOFC) stacks is the ability to hermetically seal adjacent metal and ceramic components. In our pSOFC development program, we have designed a testing technique that allows us to screen through the numerous variables involved in developing glass seals. Using this test for example, we have found that the composition of the metal component plays an important role in the strength of the seal. Microstructural analysis of the as-tested specimen sealing revealed that an interfacial reaction zone forms during joining and it appears that the thickness and composition of this layer are the dominant parameters that control joint strength. In this paper we report the details of the seal test and present results that have proven particularly significant as we develop our next generation stack design. Supporting microstructural and chemical analyses collected on the test specimens are also presented and used to interpret the results from our seal tests in an effort to identify the necessary steps in improving glass pSOFC seals.