Investigation on Glasses in Strontium Zinc Borosilicate System as Sealants for Solid Oxide Fuel Cell

Abstract:

Article Preview

Glasses in the SrO-ZnO-B2O3-SiO2 (SZBS) system with different additives like V2O5, Cr2O3, TiO2, and Al2O3 have been prepared by melt-quench method. Glasses were subjected to controlled heat treatment for conversion into glass-ceramics. Investigated glasses and glass-ceramics have thermal expansion coefficients (TEC) in the range of 95-120 x 10-7/oC (30-600 oC) which closely match with TEC of other SOFC components. XRD indicates the crystallization of Sr2ZnSi2O7 solid-solution phase in glasses upon heat treatment. Structural studies revealed that mainly Q1 and Q2 silicate structural units are present in the glass network and B2O3 enters in the network as triangular borate (BO3) structural units. Only small fraction of B2O3 enters as tetragonal borate (BO4) structural units at higher concentration of B2O3. Glass network depolymerizes with the addition of additives and concentration of Q1 units increases at the expense of Q2 units. Small addition of V2O5 in SZBS glass is beneficial for increasing TEC and achieving better flowability at lower sealing temperature. Studied SZBS glasses also show good bonding with Crofer-22-APU. Elemental line scans indicate that interdiffusion of Fe, Cr, Sr and Si across interface is responsible for good bonding with Crofer-22-APU. To show suitability of material for high temperature sealing, seals have been prepared and tested for vacuum integrity at 850oC for 500h.

Info:

Periodical:

Edited by:

B.S.S. Daniel and G.P. Chaudhari

Pages:

195-199

Citation:

B. Tiwari et al., "Investigation on Glasses in Strontium Zinc Borosilicate System as Sealants for Solid Oxide Fuel Cell", Advanced Materials Research, Vol. 585, pp. 195-199, 2012

Online since:

November 2012

Export:

Price:

$38.00

[1] R.N. Singh, High temperature seals for solid oxide fuel cells (SOFC), J. Mater. Eng. Perform. 15 (2006) 422-426.

[2] J.W. Fergus, Sealants for solid oxide fuel cell, J. Power Sources, 147 (2005) 46-57.

[3] M.K. Mahapatra, K. Lu, Glass-based seals for solid oxide fuel and electrolyzer cells – a review, Mater. Sci. Eng. R, 67 (2010) 65-85.

DOI: https://doi.org/10.1016/j.mser.2009.12.002

[4] C Lara, M.J. Pascual, A. Duran, Glass-forming ability, sinterability and thermal properties in the system RO-BaO-SiO2 (R = Mg, Zn), J. Non-Cryst. Solids, 348 (2004)149-155.

DOI: https://doi.org/10.1016/j.jnoncrysol.2004.08.140

[5] B. Tiwari, A. Dixit, G.P. Kothiyal, Study of glasses/glass-ceramics in the SrO-ZnO-SiO2 system as high temperature sealant for SOFC, Int. J. Hydrogen Energy, 36 (2011) 15002-8.

DOI: https://doi.org/10.1016/j.ijhydene.2011.04.018

[6] Babita Tiwari, A. Dixit, C.G.S. Pillai, S.C. Gadkari, G.P. Kothiyal, Crystallization kinetics and mechanism of Strontium zinc silicate glass, J. Am. Ceram. Soc. 95 (4) (2012) 1290-96.

DOI: https://doi.org/10.1111/j.1551-2916.2012.05082.x

[7] Babita Tiwari, S. Bhatacharya, A. Dixit, S.C. Gadkari and G.P. Kothiyal, Effect of V2O5 on SrO-ZnO-B2O3-SiO2 Glass-Ceramics for High Temperature Sealant Application, AIP Confer. Proc. 56th DAE Solid State Physics Symposium, 1447 (2012) 575-576.

DOI: https://doi.org/10.1063/1.4710134

[8] T. Fuss, A.M. Milankovic, C.S. Ray, C.E. Lesher, R. Youngman, D.E. Day, Ex situ XRD, TEM, IR, Raman and NMR spectroscopy of crystallization of lithium disilicate glass at high temperature, J. Non-Cryst. Solids, 352 (2006) 4101-4111.

DOI: https://doi.org/10.1016/j.jnoncrysol.2006.06.038

[9] C.L. Raluca, A. Ioan, FTIR and Raman study of silver lead borate based glasses, J. Non-Cryst. Solids, 353 (2007) 2020-(2024).

DOI: https://doi.org/10.1016/j.jnoncrysol.2007.01.066