• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.173-177
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• 2019

Thermal properties of a SiO₂-B₂O₃-BaO ternary glass system depending on compositional change of BaO have been examined to find a proper sealing material for reversible oxide cells. Glass transition temperature and thermal expansion coefficients increased simultaneously up to 55 mol% of BaO content. The structural role of BaO with regard to the thermal properties has been discussed on the basis of Raman spectroscopy results. Flowability of the glass at sealing temperature has been examined with packed glass powders of 12 mm diameter along with a high temperature optical microscope. The practical sealing property of the glass was also examined with YSZ coated with NiO-yittria stabilized zirconia (NiO-YSZ) and it showed good adhesion without noticeable reaction with NiO-YSZ layer.

• Journal of the Korean Ceramic Society
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• v.52 no.1
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• pp.19-22
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• 2015

The joining behavior of YSZ ceramics to the glasses used in the $9Al_2O_3-24ZrO_2-51SiO_2-16R_2O$ and $9Al_2O_3-24ZrO_2-51SiO_2-7La_2O_3-9R_2O$ (wt%) glass systems was investigated. The glass transition and softening temperatures were determined to be $430^{\circ}C$ and $760^{\circ}C$, respectively. The behavior of the contact angle was inversely proportional to an increase in the temperature. The Zr element in YSZ acted as a nucleation agent and contributed to the bonding behavior at the interface.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.562-566
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• 2012

A novel design of tubular segmented-in-series(SIS) solid oxide fuel cell (SOFC) sub module was presented in this paper. The tubular ceramic support was fabricated by the extrusion technique. The NiO-YSZ anode and the yttria-stabilized zirconia (YSZ) electrolyte were deposited onto the ceramic support by dip coating method. After sintering at $1350^{\circ}C$ for 5 h, a dense and crack-free YSZ film was successfully fabricated. Also, the multi-layered cathode composed of LSM-YSZ composite, LSM and LSCF were coated onto the sintered ceramic support by dip coating method and sintered at $1150^{\circ}C$. The performance of the tubular SIS SOFC cell and sub module electrically connected by the Ag-glass interconnect was measured and analysed with different fuel flow and operating temperature.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.79-84
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• 2024

Thin films of yttria-stabilized zirconia (YSZ) nanoparticles were prepared using a low-temperature deposition and crystallization process involving successive ionic layer adsorption and reaction (SILAR) or SILAR-Air spray Plus (SILAR-A+) methods, coupled with hydrothermal (175 ℃) and furnace (500 ℃) post-annealing. The annealed YSZ films resulted in crystalline products, and their phases of monoclinic, tetragonal, and cubic were categorized through X-ray diffraction analysis. The morphologies of the as-prepared films, fabricated by SILAR and SILAR-A+ processes, including hydrothermal dehydration and annealing, were characterized by the degree of surface cracking using scanning electron microscopy images. Additionally, the thicknesses of the YSZ thin films were compared by removing diffusion layers such as spectator anions and water accumulated during the air spray plus process. Crack-free YSZ thin films were successfully fabricated on glass substrates using the SILAR-A+ method, followed by hydrothermal and furnace annealing, making them suitable for application in solid oxide fuel cells.

• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.151-162
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• 1998

ZnO-BaO-$SiO_2-Al_2O_3$계 유리 및 결정화 유리 시편들을 제조하여 평판형 고체산화물 연료전지 봉착재로의 이용가능성을 조사하였다 구성층과 일치되는 열팽창 계수 및 화학적 안정성을 봉착재로의 적용에 있어 판단 기준으로 정하였다 실험된 다양한 조성의 유리 및 결정화 유리 시편들중 7.79ZnO-58.52BaO-$28.69SiO_2-5Al_2O_3$(ZBS3-A5) 결정화 유리의 측정된 열팽창 계수값은 $11.02\times10^{-6/^{\circ}C}$로써 YSZ 및 LSC의 평균 열팽창 계수 값과의 차이가 $0.07\timestimes10^{-6/^{\circ}C}$로 매우 작아 봉착시 열응력 발생의 최소화를 기대할수 있었다 이런 ZBS3-A5+LSC 접합 couple의 경우는 ZnCr2O4 의 dis-crete한 입자가 결정화 유리 부위에 형성되었고 역시 시간의 증가에 따라 이러한 입자의 성장은 없었다 특히 ZBS3-A5 구성 성분인 Ba, Zn, Sil 그리고 Al의 YSZ 및 LSC로의 확산은 없어 봉착후에 YSZ 및 LSC의 전기적 특성에 악영향을 미치지 않으리라 판단되었다.

• Journal of the Korean Ceramic Society
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• v.38 no.2
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• pp.158-165
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• 2001

고체산화물 연료전지용 밀봉재로서 전지 구성원과 열팽창계수가 유사하고 비젖음성 특성을 가지며 전지 작동온도에서 화학적 안정성을 갖는 밀봉유리를 개발하고자, BaO-Al$_2$O$_3$-La$_2$O$_3$-Ba$_2$O$_3$-SiO$_2$계 유리를 제조하여 조성 변화에 따른 열적 특성 변화와 접합후의 젖음성 및 반응성 등을 조사하였다. 유리망목 형성산화물인 B$_2$O$_3$와 SiO$_2$의 함량비 및 BaO의 망목 형성산화물(B$_2$O$_3$+SiO$_2$)에 대한 함량비 변화에 따른 유리의 열적 특성을 조사한 결과, 0.33~0.71의 B$_2$O$_3$/SiO$_2$함량비하에서 BaO/(B$_2$O$_3$+SiO$_2$)가 0.70일 때 유리의 열팽창계수는 106~111$\times$$10^{-7}$/K 이었으며 이때 연료전지 구성원인 YSZ(yttria stabilized zirconia)와의 열팽창 불일치(thermal expansion mismatch)가 가장 작았다. 또한 이러한 조성의 유리로부터 분말성형체를 제조하여 YSZ에 접합을 시도한 결과, 우수한 접합성 및 비젖음성을 확인할 수 있었으며, 800~8$50^{\circ}C$의 전지 작동온도에서 100시간까지 유지시에도 YSZ와의 계면반응이 일어나지 않음을 관찰할 수 있었다.

• Journal of the Korean Ceramic Society
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• v.44 no.8
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• pp.419-423
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• 2007

The behavior of oxygen gas participating in fining was observed in CRT (Cathode Ray Tube) glass melts doped with $Sb_2O_5\;or\;CeO_2$ by means of a yttria-stabilized zirconia (YSZ) electrode. The temperature dependence of the oxygen equilibrium pressure ($P_{o2}$) or the activity in both melts showed typical behavior corresponding to a theoretical redox reaction. In other words, the $P_{o2}$ value of melts with $CeO_2$ was lower than that of melts with $Sb_2O_5$ above $1250^{\circ}C$. The result implies that $Sb_2O_5$, is more efficient as a fining agent compared to $CeO_2$. On the other hand, melts from a batch containing $Sb_2O_5\;and\;KNO_3$ showed much higher $P_{o2}$ values compared to melts without $KNO_3$ above $1350^{\circ}C$. It is suggested that the addition of $KNO_3$ to CRT glass batch contributes partly to the first fining of the melts.

• Journal of the Korean Ceramic Society
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• v.45 no.2
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• pp.90-93
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• 2008

The oxygen gas behavior in PDP (plasma Display Panel) glass melts doped with sulfate ($SO_4^{-2}$) or blast furnace slag (BFS, $S^{2-}$) or both by means of yttria-stabilized zirconia (YSZ) electrodes was observed after the first fining. The temperature dependence of oxygen equilibrium pressure ($P_{O2}$) in each melt showed typical behavior, namely $P_{O2}$ decreased as temperature decreased. This suggests that an oxidation of $S^{4+}$ to $S^{6+}$ took place. However, the $P_{O2}$-value at constant temperature increased in the following order: BFS$P_{O2}$ of the melt doped with sulfate+BFS was much lower than that of the melt with only sulfate, although only 10% of sulfur was added by the BFS. This behavior can be explained by the redox reaction between sulfide ions in the BFS and dissolved oxygen ions in the melt during the first fining.