Glass ceramics sealants for SOFC interconnects based on a high chromium sinter alloy

Schilm, Jochen; Rost, Axel; Kusnezoff, Mihails; Michaelis, Alexander

doi:10.1111/ijac.12811

Cited by 20 publications

(9 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This study was conducted on a commercial barium alumino borosilicate glass used for SOFC sealing (K01, KERAFOL keramische Folien GmbH, Eschenbach, Germany; also supplied by Fraunhofer IKTS, Dresden, Germany [ 7 ] ). The glass transition temperature, T g = 649 °C, and the coefficient of thermal expansion, CTE 25−400 °C = 7.6 · 10 −6 K −1 , were measured in the study by Agea‐Blanco et al [ 24 ] No crystallization during heating could be detected by DTA, as also reported in the study by Agea‐Blanco et al [ 24 ] for the glass under this study.…”

Section: Methodsmentioning

confidence: 99%

Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants

et al. 2021

View full text Add to dashboard Cite

Glass powders are widely used in fabricating sintered glasses, sintered glassÀceramics, glass matrix composites, seals, and glass-bonded ceramics or pastes. [1][2][3] For many of these applications, glasses with low crystallization tendency are used, for example, for low-temperature cofired ceramics, [4,5] pastes, [6] or sealants [7,8] to ensure sufficient sinterability.Due to the low viscosity required for joining and gas tight sealing, gas bubble formation and subsequent swelling (foaming) often occur, even when organic aids are not used in powder processing. In contrast to the extensive and ongoing study of desired foaming phenomena utilized for foam glasses or glassÀceramic foams, [9][10][11][12][13][14][15] this nondesired foaming effect and its underlying mechanisms are rarely reported. Lucchini [16] observed bubble formation for sodium and calcium lead silicate glass-bonded barium hexaferrites and discussed glass volatilization as the underlying mechanism. Pore formation was also found in porcelain stoneware tiles [17] and lead borosilicate glass frits, [18] where effusing oxygen or water, physically or chemically adsorbed to the powder surface, was discussed as the foaming source. Lara et al. [19] reported foaming during the sintering and crystallization of Ca, Mg, and Zn alumosilicate glass powders used for solid oxide fuel cell (SOFC) sealing. The authors believed that density changes or gas evolution during crystallization are responsible for foaming. Undesired porosity was also reported to occur during sintering of BaO-B 2 O 3 -SiO 2 , [20] lead-free Bi 2 O 3 -B 2 O 3 -SiO 2 solder glass, [21] LTCC glass powders; [22] as well as during porcelain tiles production. [23] More recently, Agea-Blanco et al. [24] studied sintering and foaming of commercial barium zinc alumino boro silicate glass powders, used for SOFC sealing, with heating microscopy, differential thermal analysis (DTA), and vacuum hot extraction (VHE). It was shown that foaming intensity increases with milling duration. For moderately milled glass powders, consecutive storage in air could also promote foaming. Although powder compacts were pressed and sintered in air, foaming was affected by different milling atmospheres among which CO 2 proved to enhance foaming most strongly. Similarly, VHE studies revealed that foaming is predominantly driven by C, CO, and CO 2 , even for powders milled in Ar and N 2 . It was therefore concluded that foaming is caused by carbonaceous species adsorbed on the glass powder surface during milling and later storage.The present study is focused on the nature of these species and the mechanisms keeping them trapped during heating to the temperature of foaming. To ensure detectable amounts of foaming species, K01 glass powders were milled for several hours. Recrushed powder compacts, or those heated to different temperatures and quenched in air were studied with heating

show abstract

Section: Methodsmentioning

confidence: 99%

Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Further details about the crystalline phases will be discussed in the later sections of this article. Nevertheless, the CTE of HJ28 glass-ceramic is matching with CTEs of other cell components i.e., Crofer22APU (12 × 10 −6 K −1 ) and 3YSZ (10.5 × 10 −6 K −1 ), [7,31] and is suitable for the SOEC applications.…”

Section: Thermal Analysismentioning

confidence: 97%

Glass-Ceramic Sealants for SOEC: Thermal Characterization and Electrical Resistivity in Dual Atmosphere

et al. 2020

View full text Add to dashboard Cite

A Ba-based glass-ceramic sealant is designed and tested for solid oxide electrolysis cell (SOEC) applications. A suitable SiO2/BaO ratio is chosen in order to obtain BaSi2O5 crystalline phase and subsequently favorable thermo-mechanical properties of the glass-ceramic sealant. The glass is analyzed in terms of thermal, thermo-mechanical, chemical, and electrical behavior. Crofer22APU-sealant-Crofer22APU joined samples are tested for 2000 h at 850 °C in a dual atmosphere test rig having reducing atmosphere of H2:H2O 50/50 (mol%) and under the applied voltage of 1.6 V. In order to simulate the SOEC dynamic working conditions, thermal cycles are performed during the long-term electrical resistivity test. The glass-ceramic shows promising behavior in terms of high density, suitable CTE, and stable electrical resistivity (106–107 Ω cm) under SOEC conditions. The SEM-EDS post mortem analysis confirms excellent chemical and thermo-mechanical compatibility of the glass-ceramic with Crofer22APU.

show abstract

“…Many researchers 160–176 have investigated the crystallization of CAS (CaO‐Al 2 O 3 ‐SiO 2 ) glasses. CaO‐based borosilicate glasses have high CTE than BaO‐ and SrO‐based glasses 169 .…”

Section: Effect Of Different Glass Constituents On Sealing Propertiesmentioning

confidence: 99%

“…31 However, the BaO-containing glass sealant required high temperature for sealing to achieve proper gas tightness due to its higher crystallization rate with high viscosity and poor wettability to adhere with interconnecting materials. 31 CaO-containing glasses Many researchers [160][161][162][163][164][165][166][167][168][169][170][171][172][173][174][175][176] have investigated the crystallization of CAS (CaO-Al 2 O 3 -SiO 2 ) glasses. CaO-based borosilicate glasses have high CTE than BaO-and SrO-based glasses.…”

mentioning

confidence: 99%

Review on silicate and borosilicate‐based glass sealants and their interaction with components of solid oxide fuel cell

Singh

Walia

2021

Intl J of Energy Research

View full text Add to dashboard Cite

A lot of research is going on in the field of glass science to commercialize solid oxide fuel cells (SOFCs). Still, it is a big challenge to develop appropriate glass sealants for a longer duration and sustaining in the operating conditions of this power source. Mixed alkaline earth metal oxides containing silicate or borosilicate glasses could be most suitable as a rigid glass sealant in SOFCs in comparison with borate-and phosphate-based glass sealants. In this review article, the need for the sealants in the planar design of SOFCs, the effect of different modifiers, and intermediate oxides on sealing properties of glasses and glassceramics, particularly, silicate-and borosilicate-based glass sealants have been reviewed. Interaction study of glass sealants with common electrolytes and interconnect materials is also overviewed in this article. In addition to these, future perspectives and suggestions for suitable seal development are also proposed. Novelty statementThis review article is related to the glass sealants for a highly efficient and environment friendly solid oxide fuel cell energy conversion device. Still, it is a big challenge to develop an appropriate sealant to commercialize this energy device. This article provides the researchers with not only progress and latest development in the field of glass sealants but also suggestion and future prospects to develop the sealants.

show abstract

Glass ceramics sealants for SOFC interconnects based on a high chromium sinter alloy

Cited by 20 publications

References 20 publications

Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants

Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants

Glass-Ceramic Sealants for SOEC: Thermal Characterization and Electrical Resistivity in Dual Atmosphere

Review on silicate and borosilicate‐based glass sealants and their interaction with components of solid oxide fuel cell

Contact Info

Product

Resources

About