• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.295-298
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• 2009

Oxygen ionic conductors of CeScSZ electrolyte in SOFC unit cell are applied to anode and cathode as well as electrolyte to have the triple-phase-boundaries of electrochemical reaction, and it is required to decrease the sintering temperature of anode-supported electrolyte by the nanoscale of CeScSZ electrolyte powder. In this report, nanoscale CeScSZ electrolyte powder was synthesized by chemical synthesis method. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under $10{\mu}m$ was fabricated by tape casting using the synthesized CeScSZ electrolyte powder, and ionic conductivity and gas permeability of electrolyte film were evaluated. Finally the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering, in which the active layer, measuring $20{\mu}m$, was introduced in the anode layer to provide a more efficient reaction. Electrochemical evaluations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.138.2-138.2
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• 2010

Scandium-doped zirconium, ScSZ-based electrolyte, provides higher oxygen conductivity than YSZ and nano-based electrolyte materials are ideal for fabricating thin film electrolyte membrane of SOFC unit cell. Moreover, it may be applied to anode and cathode as well as electrolyte as ionic conductor. In this report, nano-based ScSZ-based electrolyte powder was prepared by co-precipitation synthesis. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under $10{\mu}m$ was fabricated by tape casting and co-firing using the synthesized ScSZ-based powders, and ionic conductivity and gas permeability of electrolyte film were evaluated. Finally, the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering. Electrochemical evaluations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2004년도 추계총회 및 학술발표회
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• pp.35-35
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• 2004

• 세라미스트
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• 제21권4호
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• pp.378-387
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• 2018

The optimal fabrication conditions for $Gd_{0.1}Ce_{0.9}O_{2-{\delta}}$(GDC) buffer layer and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ (LSCF) cathode on 1mol% $CeO_2-10mol%\;Sc_2O_3$ stabilized $ZrO_2$ (CeScSZ) electrolyte were investigated for application of IT-SOFCs. GDC buffer layer was used in order to prevent undesired chemical reactions between LSCF and CeScSZ. These experiments were carried out with $5{\times}5cm^2$ anode supported unit cells to investigate the tendencies of electrochemical performance, Microstructure development and interface reaction between LSCF/GDC/CeScSZ along with the variations of GDC buffer layer thickness, sintering temperatures of GDC and LSCF were checked, respectively. Electrochemical performance was analyzed by DC current-voltage measurement and AC impedance spectroscopy. Microstructure and interface reaction were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Although the interfacial reaction between these materials could not be perfectly inhibited, We found that the cell, in which $6{\mu}m$ GDC interlayer sintered at $1200^{\circ}C$ and LSCF sintered at $1000^{\circ}C$ were applied, showed good interfacial adhesions and effective suppression of Sr, thereby resulting in fairly good performance with power density of $0.71W/cm^2$ at $800^{\circ}C$ and 0.7V.

• 전기화학회지
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• 제10권4호
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• pp.288-294
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• 2007

Modified oxalate method에 의해 합성한 중온형 Solid Oxide Fuel Cell 용 LSCF cathoded의 pH 변화에 따른 분말특성 및 여러 종류의 전해질에 따른 전극특성에 대해 연구하였다. LSCF를 합성하기 위한 출발물질로는 La, Sr, Co 및 Fe의 염화물과 oxalic acid, ethanol 및 $NH_4OH$를 사용하여, $80^{\circ}C$ 에서 pH 2, 6, 7, 8, 9 및 10에서 합성하였다. 합성한 LSCF 분말은 pH $2{\sim}9$까지는 단일상의 LSCF 결정상을 생성하였다. 그러나, PH 10에서는 LSCF결정상 외에 이차상인 $La_2O_3$ 결정상이 나타났으며, 또한 $800^{\circ}C$에서 4시간 하소한 경우 50 nm정도의 작은 크기를 나타내었다. 합성한 LSCF cathode 분말의 전기전도도는 pH 7에서 합성한 LSCF 분말의 경우 $600^{\circ}C$부터 $900^{\circ}C$까지 측정하였을 때 약 950 S/cm의 높은 값을 나타내었다. 또한 분극저항의 경우 같은 합성 조건에서 합성한 LSCF 분말이라도 하소조건에 따라 다른 결과를 나타내었는데, $800^{\circ}C$에서 하소한 분말의 경우 $1200^{\circ}C$에서 하소한 분말 보다 낮은 분극저항을 나타내었다. 특히 $800^{\circ}C$에서 4시간 하소하여 합성한 LSCF 분말은 $600^{\circ}C$에서 Scandia Stabilized Zirconia (ScSZ), yttria (8mol.%)-stabilized zirconia(8Y-YSZ) 및 Gadolinium Doped Ceria(GDC) 전해질을 사용하였을 때, 전극면적이 $0.5\;cm^2$일 때 각각 2.52, 1.54 및 $2.58\;{\Omega}$을 나타내었다.