Ceramic sealants

J. Malzbender, J. Monch, R.W. Steinbrech, T. Koppitz, S.M. Gross, and J. Remmel, Symmetric Shear Rest of Glass-Ceramic Sealants at SOFC Operation Temperature, J. Mater. Sci., 42, pp. 6297-6301, 2007. 

A.S. Wagh, S. Jeong, and R. McDaniel, Chemically bonded phosphate ceramic sealant formulations for oil field applications, Argonne National Laboratory, Patent applied for. 

The E-design stack, shown in Fig. lA, consists of a relatively thick metallic interconnect with machined gas channels on both sides and a metallic picture frame for the cell, brazed to the interconnect by a metal solder. Sealing is obtained by glass ceramic sealants applied to the planar cell and frame surfaces using an automated dispenser. A fine Ni-mesh is spot-welded to the fuel side of the interconnect in order to improve the electrical contact between interconnect and anode substrate. On the air side usually a lanthanum cobaltite (LC) contact layer is sprayed onto the ribs of the interconnect. 

GLASS-CERAMIC SEALANTS FOR SOFC-BASED SYSTEMS... 

Glass-Ceramic Sealants For SOFC-Based Systems... 

Figure 1. SEM micrographs of glass-ceramic sealants in contact with various solid...

Y., Glass-ceramics sealants in Ca0-Al203-Si02 system. In SOFC-V, Ed. U. Stimming, the Electrochemical Society, 1997, PV-97-40, p. 652-660. 

Table 2-1. Compositions of glass/glass-ceramic sealants (mol%)...

K. Ley, M. Krumpelt, R. Kumar, et ah. Glass-ceramic sealants for solid oxide fuel cells Part I. Physical properties. Journal of Materials Research, 11 (1996) 1489-1493. 

S.B. Sohn, S.Y Choi, G.H. Kim, et ah. Suitable glass-ceramic sealant for planar solid-oxide fuel cells. Journal of the American Ceramic Society, 87 (2004) 254-260. 

V.A.C. Haanappel, V. Shemet, S.M. Gross, et al., Behaviour of various glass-ceramic sealants with ferritic steels under simulated SOFC stack conditions. Journal of Power Sources, 150 (2005) 86-100. 

Table 113 Common compositional modifiers for silicate-based glass-ceramic sealants.

A list of common constituents often employed in high-temperature glass-ceramic sealants is provided in Table 11.3, along with their functional... 

YSZ-Fecralloy joint strength specimens joined with Ag4CuO and with G-18, the barium aluminosilicate glass-ceramic sealant discussed previously. Note that the glass joints experience a substantial loss in strength beyond 10 thermal cycles at 75 °C min , whereas the mpture strength of the air-brazed specimens remains constant as a function of thermal cychng. 

Meinhardt, K.D., Kim, D.S., Chou, Y.S., and Weil, K.S. (2008) Synthesis and properties of a barium aluminosilicate solid oxide fuel cell glass-ceramic sealant. J. Power Sources, 182, 188-196. 

Ghosh, S., Das Sharma, A., Kundu, P., Mahanty, S., and Basu, R.N. (2008) Development and characterizations of BaO—CaO—AI2O3 —Si02 glass-ceramic sealants for intermediate temperature solid oxide fuel cell application. J. Non-Cryst. Solids, 354, 4081-4088. 

Pascual, M.J., Guillet, A., and Duran, A. (2007) Optimization of glass-ceramic sealant compositions in the system MgO—BaO—Si02 for solid oxide fuel cells (SOFC)./. Power Sources, 169, 40-46. 

D Herin Bytner, F.D., Leone, P., and Ferraris, M. (2010) New glass and glass-ceramic sealants for planar solid oxide fuel cells. J. Eur. Ceram. Soc., 30, 933-940. 

Shemet, V., Vinke, I.C., and Steinbrech, R.W. (2006) Chemical interaction between glass—ceramic sealants and interconnect steels in SOFC stacks. 

Figure 17.7 Characterization of areas of special interest during stack dissection by optical microscopy (a) stack overview photograph (b) higher magnification of marked rectangle in (a) (c) optical microscopy photograph from the rear side of the color-changed zone showing unwanted interaction between the cathode and the glass—ceramic sealant.

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