A novel “refractory” Sr-Ca-Y-B-Si sealing glass (glass-ceramic) was developed for solid oxide fuel cells (SOFCs). The objective was to develop sealing glass with desired thermal properties and minimal interfacial reactions with SOFC components, ceramic electrolyte and metallic interconnect. The current glass was different from conventional sealing glass in that the sealing temperatures were targeted higher (>950 degree C) and hence more refractory. Six glasses were formulated and made by conventional glass-making process. Thermal properties were characterized in the glass state and the sintered (crystallized) state. The effect of formulation on thermal properties was discussed. Candidate glasses were also aged for 1000 to 2000 h at elevated temperatures. Thermal expansion measurements showed minimal change after aging. A candidate glass (YSO-1) was used in sealing ceramic electrolyte to a metallic interconnect from 900 degree C to 1050 degree C in air. The interfacial microstructure was characterized and SrCrO4 was identified near the metal interface. Possible reaction mechanism for the chromate formation was discussed.
Revised: March 10, 2011 |
Published: July 1, 2007
Citation
Chou Y.S., J.W. Stevenson, and P. Singh. 2007.Novel refractory alkaline earth silicate sealing glasses for planar solid oxide fuel cells.Journal of the Electrochemical Society 154, no. 7:B644-B651.PNNL-SA-52170.doi:10.1149/1.2733868