A modeling study on the thermomechanical behavior of glass-ceramic and self-healing glass seals at elevated temperatures

Journal Article · Fri May 15 04:00:00 EDT 2009 · Journal of Power Sources, 190(2):476-484

DOI:https://doi.org/10.1016/j.jpowsour.2009.01.006· OSTI ID:963572

Govindaraju, Nirmal; Liu, Wenning N; Sun, Xin; Singh, Prabhakar; Singh, R

Hermetic gas seals are critical components for planar solid oxide fuel cells. This article focuses on comparative evaluation of a glass-ceramic developed by the Pacific Northwest National Laboratory (PNNL) and a self-healing glass seal developed by the University of Cincinnati. The stress and strain levels in the Positive electrode-Electrolyte-Negative electrode (PEN) seal in one cell stack are evaluated using a multi-physics simulation package developed at PNNL. Simulations were carried out with and without consideration of clamping force and stack body force, respectively. The results indicate that the overall stress and strain levels are dominated by the thermal expansion mismatches between the different cell components. Further, compared with glass-ceramic seal, the self-healing glass seal results in much lower steady state stress due to its much lower stiffness at the operating temperature of SOFC, and also exhibits much shorter relaxation times due to high creep rate. It is also noted that the self-healing glass seal will experience continuing creep deformation under the operating temperature of SOFC therefore resulting in possible overflow of the sealing materials. Further stopper material may need to be added to maintain its geometric stability during operation.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 963572
• Report Number(s): PNNL-SA-62645; AA2530000
• Journal Information: Journal of Power Sources, 190(2):476-484, Journal Name: Journal of Power Sources, 190(2):476-484
• Country of Publication: United States
• Language: English

Related Subjects

Solid-oxide fuel cell
glass seals
thermomechanical behavior
modeling
creep