Research Of Al₂O₃/glass-based Multi-layer Composite Seals For Solid Oxide Fuel Cells

Solid Oxide Fuel Cell (SOFC) attract more and more researchers’ attention aroundthe world due to its high efficient, clean and extensive apply situation. Nowadays, researchof SOFC technology is smoothly, but seals become the serious problem which restrictingthe development of SOFC. In this paper, a multi-layer composite seals with sandwichedstructure for SOFC is studied, which combined advantage of classical Al2O3-Al seals andglass-ceramic composite seals.New BaO-B2O3-SiO2system glass has been researched, the soften temperature ofglass is680°C. This glass will have little crystallization when heated at800°C for60min,which can reinforce the glass matrix. The result finds out that glass-ceramic slurry with20wt%Al2O3has the suitable strength and deformability. Al2O3/glass-based multi-layercomposite seals include Al2O3-based tape as support and glass-ceramic slurry as binderjoining the interface of adjacent components.The thermal cycle characteristics are greatly improved by using this multi-layercomposite seals, and the corresponding leakage rates are lower than0.025sccm cm-1for20thermal cycles at the inlet pressure ranging from0.5psi to2psi. SEM investigationsshow a very compact and good adhesion between the adjacent components, which canreduce the most of leakage paths. Single cell testing is used to examine the performance ofthe seals. The open circuit voltage of the cell in test can achieve1194mV. At a constanteletro-discharge current of30A, the voltage of cell is stabilized at850mV for50h. Theresults demonstrate that this multi-layer composite seals is a good candidate for SOFCapplication.In conclusion, Al2O3/glass-based multi-layer composite seals have good sealingperformance, and which can release the high temperature stress of SOFC. In single-celltest, Al2O3/glass-based multi-layer composite seals also show good performance, andwhich will have good application foreground in SOFC.