• 한국세라믹학회지
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• 제32권2호
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• pp.197-208
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• 1995

${\gamma}$-LiAlO2 fibers for fiber reinforced molten carbonate fuel cell (MCFC) matrix have been produced from LiAlO2 complex polymeric sols using the sol-gel process. The stable and spinnable LiAlO2 sols could be synthesized by mixing LiNO3 alcohol solutions in aluminum complex polymeric sols prepared through the condensationpolymerization reaction of 1 more of aluminum tri-sec-butoxide with 0.55 mole of mixed chelates (mole ratio of acetylaceton/triethanolamine=0.25/0.3). It was found that the viscosity range for fiber-spinning should be higher than 30 poise. The defect-free flexible ${\gamma}$-LiAlO2 fibers with the average tensile strength of 350 MPa could be obtained when the spinned fibers were heat-treated to 120$0^{\circ}C$ on the specified heating schedule after dried at room temperature.

• 한국세라믹학회지
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• 제29권5호
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• pp.377-382
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• 1992

For the development of solid oxide fuel cell the joined interface formation between perovskite oxygen electrode and YSZ solid electrolyte is emphasized in the aspect of reducing the undisirable overpotential. The diffusion couple of LaMnO3 and YSZ was prepared by hot pressing at 130$0^{\circ}C$ in the flow of oxygen gas. The high temperature solid state reaction mechanism between LaMnO3 and YSZ is discussed on the basis of the cation composition profile through EDX analysis. The cation components in perovskite compound diffuse considerably into YSZ, while cations of YSZ diffuse little into perovskite.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.364-367
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• 2006

The decrease of polarization resistance in cathode is the key point for intermediate temperature SOFC(Solid Oxide Fuel Cell). In this study, the Influence of Co substitution in B-site at perovskite PSCM (Pr0.3Sr0.7CoxMn(1-x)) was investigated. The PSCM series exhibits excellent MIEC(Mixed ionic Electronic Conductor) properties. The ASR(Area Specific Resistance) of PSCM3773 was $0.174{\Omega}cm^2\;at\;700^{\circ}C$. The activation energy of PSCM3773 was also lower than other compositions of PSCM. The ASR values were increased gradually during the thermal cycling test of PSCM37773 due to the delamination between electrolyte and cathode materials.

• 한국수소및신에너지학회논문집
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• 제18권3호
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• pp.342-347
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• 2007

The research on production and application of hydrogen as an alternative energy in the future is being carried out actively. It hydrogen storage is necessary in order that user use hydrogen economically without much difficulty. Among the ways of hydrogen storage the method which is compressed hydrogen gas by high pressure is easier for application than other methods. In this study, we have been calculated gas with changing pressure and temperature variation of container wall through applied to mass and energy balance equation when compressing hydrogen by high pressure, and also to Beattie-Bridgeman equation of state for the kinetic of hydrogen. We will apply above date as a preliminary for design of hydrogen storage tank.

• 한국세라믹학회지
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• 제47권1호
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• pp.71-74
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• 2010

We have investigated protonic conduction in highly dense (>98%) polycrystalline Y-doepd $BaZrO_3$ (BYZ) ceramic with an average grain size of ~85 nm. It is observed that the protonic conductivity across the grain boundaries in this nano-crystallilne BYZ (n-BYZ) is significantly higher than the microcrystalline counterpart. Such a remarkable enhancement in grain boundary conductivity results in high overall conductivity that may allow this chemically stable protonic conductor to serve as a solid electrolyte for low-temperature solid oxide fuel cell applications.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.87-90
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• 2005

This paper presents an evaluation of the effect of titanium dioxide nanoparticles in sulfonated poly(ether ether ketone) (SPEEK) with sulfonation degree of 57%. A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticles content. Their water uptake, methanol permeability and proton conductivity as a function of temperature were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and water swelling. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of morphology, membranes are homogeneous and exhibit a good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with standard nafion membrane.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1262-1266
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• 2009

The study aims to analyzed and identify the heat transfer characteristics of heating unit for car using experimental method in order to design DPH. The temperature comparison processes were done with various experimental conditions. In addition, the optimal conditions of DPH design were proposed as field test in real car, hot air flow, transient situation.

• 한국세라믹학회지
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• 제42권2호
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• pp.77-80
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• 2005

A series of proton conductive composite membranes based on poly(vinyl alcohol) and phosphosilicate gels powders were successfully prepared. The proton conductivity of these composite was attributed to the phosphosilicate gel, which derived from tetraethoxysilane and phosphoric acid by sol-gel process at a molar ratio of P/Si = 1.5. The proton conductivity increased with increasing both the content of phosphosilicate gel and relative humidity. Temperature dependence of conductivity showed a Vogel-Tamman-Fulcher type behavior, indicating that proton was transferred through a liquidlike phase formed in micropores of phosphosilicate gel. The high conductivity of 0.065 S/cm with a membrane containing 60 wt$\%$ of the gel was obtained at $60^{\circ}C$ at $90\%$ relative humidity.

• 한국세라믹학회지
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• 제31권5호
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• pp.477-484
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• 1994

The yttria stabilized zirconia(YSZ) thin films for solid oxide fuel cell (SOFC) were fabricated by an electrochemical vapor deposition(EVD) technique using YCl3+ZrCl4+H2O gas system. The YSZ films were deposited under reduced pressure at the temperature of 1000~120$0^{\circ}C$ on the porous alumina substrates. The deposition rate, chemical composition and growth morphology were investigated by SEM, XRD, EDS. The growth rates of the films obeyed a parabolic rate law, representing that the growing process is controlled by an electrochemical transport through the YSZ film. The Y2O3 content of the films was about 10 mol%, equal to the composition of metal chloride reactant gases, approximately. The YSZ films were highly dense, the growing features showed columnar structure and surface morphologies were changed with the EVD conditions.

• 한국환경과학회지
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• 제18권10호
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• pp.1071-1077
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• 2009

A novel pretreatment technique was applied to the conventional Pt/alumina catalyst to prepare for the highly efficient catalyst for the preferential oxidation of carbon monoxide in hydrogen-rich condition. Their performance was investigated by selective CO oxidation reaction. CO conversion with the oxygen-treated Pt/Alumina catalyst increased remarkably especially at the low temperature below $100^{\circ}C$. This result is promising for the normal operation of the proton exchange membrane fuel cell (PEMFC) without CO poisoning of the anode catalyst. XRD analysis results showed that metallic Pt peaks were not observed for the oxygen-treated catalyst. This implies that well dispersed small Pt particles exist on the catalyst. This result was continued by high resolution transmission electron microscopy (HRTEM) analysis. Consequently, it can be concluded that highly dispersed Pt nanoparticles could be prepared by the novel pretreatment technique and thus, CO conversion could be increased considerably especially at the low temperatures below $100^{\circ}C$.