Removal of solid oxide fuel cell glass-ceramic sealants from metallic interconnectors after operation

Year 2025, Volume: 14 Issue: 1, 370 - 381, 15.01.2025

Tolga Altan

https://doi.org/10.28948/ngumuh.1599444

Abstract

Glass/glass-ceramic materials used as solid oxide fuel cell (SOFC) sealing elements are known to provide a much more effective seal than other alternative approaches. On the other hand, it is very difficult to remove glass-ceramics, which provide an effective adhesion with the surfaces after operation in SOFC systems, from metallic current collectors and to reuse the related metallic elements. In this study, the dissolution behavior of glass-ceramic sealing elements in nitric acid solutions of different concentrations (5%, 10%, 15%, 20% and 25% by volume) for different holding times (30-240 minutes) is investigated. Tape casting method is used in the production of glass-ceramics and bonding strengths before/after chemical treatment are determined by tensile tests using Crofer interconnectors. After the tests, the interface properties are examined by stereoscopic microscope and profilometer analyses. It is found that, under the optimum conditions identified, the glass-ceramic can be completely removed from the metal surfaces and that the oxide layers remaining on the sample surfaces after dissolution provide a 70% improvement in bonding strength and have a positive effect on sealing performance.

Keywords

Solid oxide fuel cell, Glass-ceramic, Nitric acid, Bonding strength, Recycling

Katı oksit yakıt pili cam-seramik sızdırmazlık elemanlarının çalışma sonrası metalik ara bağlantılardan bertarafı

Abstract

Katı oksit yakıt pili (KOYP) sızdırmazlık elemanı olarak kullanılan cam/cam-seramik malzemelerin diğer alternatif yaklaşımlara göre çok daha etkin bir sızdırmazlık sağladığı bilinmektedir. Öte yandan, KOYP sistemlerinde çalışma sonrası yüzey ile etkili bir yapışma sağlayan cam-seramiklerin metalik akım toplayıcılardan sökülmesi ve ilgili metalik elemanların tekrar kullanılması oldukça zordur. Bu çalışmada cam-seramik sızdırmazlık elemanlarının farklı konsantrasyonlardaki (hacimce %5, %10, %15, %20 ve %25) nitrik asit çözeltilerinde farklı bekletme süreleri (30-240 dakika) için çözünme davranışı incelenmiştir. Testlerde kullanılan cam-seramiklerin üretiminde şerit döküm yöntemi kullanılmış ve kimyasal işlem öncesi/sonrası yapışma mukavemetleri Crofer malzemeden imal edilen ara bağlantılar kullanarak çekme testi ile belirlenmiştir. Testler sonrasında ara yüzey özellikleri stereoskopik mikroskop ve profilometre analizleri ile incelenmiştir. Belirlenen optimum koşullar altında cam-seramiklerin metal yüzeylerinden tamamen uzaklaştırılabildiği ve çözünme sonrası numune yüzeylerinde kalan oksit tabakaların etkisiyle %70 oranında yapışma mukavemetinde iyileşme sağlayıp sızdırmazlık performansı üzerinde olumlu etkileri olduğu tespit edilmiştir.

Keywords

Katı oksit yakıt pili, Cam-seramik, Nitrik asit, Yapışma mukavemeti

References

• J.W. Fergus, Sealants for solid oxide fuel cells. Journal of Power Sources, 147(1-2), 46-57, 2005. https://doi.org/10.1016/j.jpowsour.2005.05.002.
•    M. Mahapatra and K. Lu, Glass-based seals for solid oxide fuel and electrolyzer cells–a review. Materials Science and Engineering: R: Reports, 67(5-6), 65-85, 2010. https://doi.org/10.1016/j.mser.2009.12.002.
•    X.-V. Nguyen, C.-T. Chang, G.-B. Jung, S.-H. Chan, W.-T. Lee, S.-W. Chang and I.-C. Kao, Study of sealants for SOFC. International Journal of Hydrogen Energy, 41(46), 21812-21819, 2016. https://doi.org/10.1016/j.ijhydene.2016.07.156.
•    F. Smeacetto, M. Salvo, M. Santarelli, P. Leone, G.A. Ortigoza-Villalba, A. Lanzini, L.C. Ajitdoss and M. Ferraris, Performance of a glass-ceramic sealant in a SOFC short stack. International Journal of Hydrogen Energy, 38(1), 588-596, 2013. https://doi.org
•    K. Singh and T. Walia, Review on silicate and borosilicate‐based glass sealants and their interaction with components of solid oxide fuel cell. International Journal of Energy Research, 45(15), 20559-20582, 2021. https://doi.org/10.1002/er.7161.
•    D.U. Tulyaganov, A.A. Reddy, V.V. Kharton and J.M.F. Ferreira, Aluminosilicate-based sealants for SOFCs and other electrochemical applications − A brief review. Journal of Power Sources, 242, 486-502, 2013. https://doi.org/10.1016/j.jpowsour.2013.05.099.
•    M. Garai, A.R. Molla, A.A. Reka and B. Karmakar, Wide thermal expansion in Ag0/Au0 nanoparticle doped SiO2-MgO-Al2O3-B2O3-K2O-MgF2 glass-ceramics. Materials Today: Proceedings, 50, 134-138, 2022. https://doi.org/10.1016/j.matpr.2021.09.549.
•    M. Garai and S. Roy, Performance evaluation for Ag and Au nanoparticle containing K2O‐MgO‐B2O3‐Al2O3‐SiO2‐F glass sealants for SOFC application. International Journal of Ceramic Engineering & Science, 5(2), e10172, 2023. https://doi.org/10.1002/ces2.10172.
•    B. Timurkutluk, Y. Ciflik and H. Korkmaz, Strength evaluation of glass–ceramic composites containing yttria stabilized zirconia after thermal cycling. Ceramics International, 41(5), 6985-6990, 2015. https://doi.org/10.1016/j.ceramint.2015.01.153.
• Y.-S. Chou, J.W. Stevenson and R.N. Gow, Novel alkaline earth silicate sealing glass for SOFC: Part II. Sealing and interfacial microstructure. Journal of Power Sources, 170(2), 395-400, 2007. https://doi.org/10.1016/j.jpowsour.2007.03.060.
• M. Garai, S.P. Singh and B. Karmakar, Mica (KMg3AlSi3O10F2) based glass-ceramic composite sealant with thermal stability for SOFC application. International Journal of Hydrogen Energy, 46(45), 23480-23488, 2021. https://doi.org/10.1016/j.ijhydene.2020.10.252.
• Z. Li, B. Peng, T. Zhang, H. Li, L. Li, C. Wen and K. Chen, Improving sealing performance of borosilicate glass-ceramics for solid oxide fuel cell applications: Effect of AlN. Journal of the European Ceramic Society, 39(14), 4194-4201, 2019. https://doi.org/1
• M.F. Hasanabadi, M. Faghihi-Sani, A. Kokabi, S. Groß-Barsnick and J. Malzbender, Room-and high-temperature flexural strength of a stable solid oxide fuel/electrolysis cell sealing material. Ceramics International, 45(1), 733-739, 2019. https://doi.org/10.1016
• E.V. Stephens, J.S. Vetrano, B.J. Koeppel, Y. Chou, X. Sun and M.A. Khaleel, Experimental characterization of glass–ceramic seal properties and their constitutive implementation in solid oxide fuel cell stack models. Journal of Power Sources, 193(2), 625-631,
• M. Ferraris, S. De la Pierre, A. Sabato, F. Smeacetto, H. Javed, C. Walter and J. Malzbender, Torsional shear strength behavior of advanced glass-ceramic sealants for SOFC/SOEC applications. Journal of the European Ceramic Society, 40(12), 4067-4075, 2020. ht
• C.-K. Lin, T.-W. Lin, S.-H. Wu, W.-H. Shiu, C.-K. Liu and R.-Y. Lee, Creep rupture of the joint between a glass-ceramic sealant and lanthanum strontium manganite-coated ferritic stainless steel interconnect for solid oxide fuel cells. Journal of the European
• C.-K. Lin, Y.-A. Liu, S.-H. Wu, C.-K. Liu and R.-Y. Lee, Joint strength of a solid oxide fuel cell glass–ceramic sealant with metallic interconnect in a reducing environment. Journal of Power Sources, 280, 272-288, 2015. https://doi.org/10.1016/j.jpowsour.201
• B. Timurkutluk, T. Altan, S. Celik, C. Timurkutluk and Y. Palacı, Glass fiber reinforced sealants for solid oxide fuel cells. International Journal of Hydrogen Energy, 44(33), 18308-18318, 2019. https://doi.org/10.1016/j.ijhydene.2019.05.116.
• M. Jabbari, R. Bulatova, A. Tok, C. Bahl, E. Mitsoulis and J.H. Hattel, Ceramic tape casting: a review of current methods and trends with emphasis on rheological behaviour and flow analysis. Materials Science and Engineering: B, 212, 39-61, 2016. https://doi.
• A.O. Zhigachev, E.A. Agarkova, D.V. Matveev and S.I. Bredikhin, CaO-SiO2-B2O3 Glass as a Sealant for Solid Oxide Fuel Cells. Ceramics, 5(4), 642-654, 2022. https://doi.org/10.3390/ceramics5040047.
• K. Kanbara, N. Uchida, K. Uematsu, T. Kurita, K. Yoshimoto and Y. Suzuki, Corrosion of silicon nitride ceramics by nitric acid. MRS Online Proceedings Library (OPL), 287, 533, 1992. https://doi.org/10.1557/PROC-287-533.
• I. Ropuš, L. Ćurković, H. Cajner and S. Rončević, Optimization of alumina ceramics corrosion resistance in nitric acid. Materials, 15(7), 2579, 2022. https://doi.org/10.3390/ma15072579.
• H. Jang, Y. Chung, S. Whangbo, T. Kim, C. Whang, S. Lee and S. Lee, Effects of chemical etching with nitric acid on glass surfaces. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 19(1), 267-274, 2001. https://doi.org/10.1116/1.13.
• T.H. Elmer and M.E. Nordberg, Solubility of silica in nitric acid solutions. Journal of the American Ceramic Society, 41(12), 517-520, 1958. https://doi.org/10.1111/j.1151-2916.1958.tb12907.x.
• M.D.L. de Castro and J.L.L. García, Chapter 5 - Microwave-assisted solid sample treatment. in: M.D.L. de Castro, J.L.L. García (Eds.), Techniques and Instrumentation in Analytical Chemistry, Elsevier, pp. 179-232, 2002.
• A. Iversen and B. Leffler, 3.04 - Aqueous Corrosion of Stainless Steels. in: B. Cottis, M. Graham, R. Lindsay, S. Lyon, T. Richardson, D. Scantlebury, H. Stott (Eds.), Shreir's Corrosion, Elsevier, pp. 1802-1878, Oxford, 2010.
• S. Ningshen, U. Kamachi Mudali, G. Amarendra and B. Raj, Corrosion assessment of nitric acid grade austenitic stainless steels. Corrosion Science, 51(2), 322-329, 2009. https://doi.org/10.1016/j.corsci.2008.09.038.
• SCHOTT UK Ltd., Technical Details of Sealing and Solder Glass Frits. https://www.schott.com/en-gb/products/sealing-and-solder-glass-p1000291/technical-details, Accessed 1 January 2025.
• D. Munz, Fracture Mechanics: Linear Elastic. Encyclopedia of Materials: Science and Technology, 3300-3306, 2001. https://doi.org/10.1016/B0-08-043152-6/00589-1.
• W. Weibull, A statistical distribution function of wide applicability. Journal of applied mechanics, 18(3), 293-297, 1951. https://doi.org/10.1115/1.4010337.
• S. Celik, Influential parameters and performance of a glass-ceramic sealant for solid oxide fuel cells. Ceramics International, 41(2, Part B), 2744-2751, 2015. https://doi.org/10.1016/j.ceramint.2014.10.089.
• R. Li, M. Tao, P. Wang, J. Yang, B. Ma, B. Chi and J. Pu, Effect of interconnect pre-oxidation on high-temperature wettability and mechanical properties of glass seals in SOFC. Journal of the American Ceramic Society, 104(12), 6172-6182, 2021. https://doi.org
• T. Altan and S. Celik, Effect of surface roughness of the metallic interconnects on the bonding strength in solid oxide fuel cells. International Journal of Hydrogen Energy, 45(60), 35118-35129, 2020. https://doi.org/10.1016/j.ijhydene.2020.03.136.
• T. Zhang, R.K. Brow, W.G. Fahrenholtz and S.T. Reis, Chromate formation at the interface between a solid oxide fuel cell sealing glass and interconnect alloy. Journal of Power Sources, 205, 301-306, 2012. https://doi.org/10.1016/j.jpowsour.2012.01.043.
• W.N. Liu, X. Sun, E. Stephens and M.A. Khaleel, Life prediction of coated and uncoated metallic interconnect for solid oxide fuel cell applications. Journal of Power Sources, 189(2), 044-1050, 2009. https://doi.org/10.1016/j.jpowsour.2008.12.143.
• M.A. Laguna-Bercero, High temperature electrolysis. Springer Nature, Switzerland, 2023.
• B. Hua, J. Pu, W. Gong, J. Zhang, F. Lu and L. Jian, Cyclic oxidation of Mn–Co spinel coated SUS 430 alloy in the cathodic atmosphere of solid oxide fuel cells. Journal of Power Sources, 185(1), 419-422, 2008. https://doi.org/10.1016/j.jpowsour.2008.06.055.
• Z. Yang, G.-G. Xia, X.-H. Li and J.W. Stevenson, (Mn,Co)3O4 spinel coatings on ferritic stainless steels for SOFC interconnect applications. International Journal of Hydrogen Energy, 32(16), 3648-3654, 2007. https://doi.org/10.1016/j.ijhydene.2006.08.048.
• Y.-S. Chou, J.W. Stevenson and P. Singh, Effect of pre-oxidation and environmental aging on the seal strength of a novel high-temperature solid oxide fuel cell (SOFC) sealing glass with metallic interconnect. Journal of Power Sources, 184(1), 238-244, 2008. h