Electrical Stability of a Novel Refractory Sealing Glass in a Dual Environment for Solid Oxide Fuel Cell Applications

A novel refractory alkaline-earth silicate (Sr-Ca-Y-B-Si) sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was sealed between two metallic interconnect plates and tested for electrical stability at elevated temperatures and dual environments under dc loading. The isothermal aging results showed very stable electrical resistivity with values 5-9 orders of magnititudes higher than typical SOFC function materials at 850 degrees C for similar to 700 h. For comparison, a state-of-the-art sealing glass (G18, Ba-Ca-Al-B-Si) was also evaluated in a similar condition and showed a less stable condition in accelerated tests at 830 degrees C for similar to 100 h. Interfacial microstructure was characterized and possible reactions are discussed.