In the segmented-in-series solid-oxide fuel cells (SIS-SOFCs), fabrication techniques which use decalcomania paper have many advantages, i.e., an increased active area of the electrode; better interfacial adhesion property between the anode, electrolyte and cathode; and improved layer thickness uniformity. In this work, a cell-stack was fabricated on porous ceramic flattened tube supports using decalcomania paper, which consists of an anode, electrolyte, and a cathode. The anode layer was 40μm thick, and was porous. The electrolyte layers exhibited a uniform thickness of about 20μm with a dense structure. Interfacial adhesion was improved due to the dense structure. The cathode layers was 30μm thick with porous structure, good adhesion to the electrolyte. The ohmic resistance levels at 800, 750 and 700˚C were measured, showing values of 1.49, 1.58 and 1.65Ω·cm2, respectively. The polarization resistances at 800, 750 and 700˚C were measured to be 1.63, 2.61 and 4.17cm2, respectively. These lower resistance values originated from the excellent interfacial adhesion between the anode, electrolyte and cathode. In a two-cell-stack SOFC, open-circuit voltages(OCVs) of 1.915, 1.942 and 1.957 V and maximum power densities(MPD) of 289.9, 276.1 and 220.4mW/cm2 were measured at 800, 750 and 700˚C, respectively. The proposed fabrication technique using decalcomania paper was shown to be feasible for the easy fabrication of segmented-in-series flattened tube SOFCs.

The properties of SOFC unit cells manufactured using the decalcomania method were investigated. SOFC unit cell manufacturing using the decalcomania method is a very simple process. In order to minimize the ohmic loss of flattened tube type anode supports of solid oxide fuel cells(SOFC), the cells were fabricated by producing an anode function layer, YSZ electrolyte, LSM electrode, etc., on the supports and laminating them. The influence of these materials on the power output characteristics was studied when laminating the components and laminating the anode function layer between the anode and the electrolyte to improve the output characteristics. Regarding the performance of the SOFC unit cell, the output was 246 mW/cm2 at a temperature of 800˚C in the case of not laminating the anode function layer; however, this value was improved by a factor of two to 574 mW/cm2 due to the decrease of the ohmic resistance and polarization resistance of the cell in the case of laminating the anode function layer. The outputs appeared to be as high as 574 and 246 mW/cm2 at a temperature of 800˚C in the case of using decalcomania paper when laminating the electrolyte layer using the in dip-coating method; however, the reason for this is that interfacial adhesion was improved due to the dense structure, which leads to a thin thickness of the electrolyte layer.

For this paper, we investigated the area specific resistance (ASR) of commercially available ferritic stainless steels with different chemical compositions for use as solid oxide fuel cells (SOFC) interconnect. After 430h of oxidation, the STS446M alloy demonstrated excellent oxidation resistance and low ASR, of approximately 40 mΩcm2, of the thermally grown oxide scale, compared to those of other stainless steels. The reason for the low ASR is that the contact resistance between the Pt paste and the oxide scale is reduced due to the plate-like shape of the Cr2O3(s). However, the acceptable ASR level is considered to be below 100 mΩcm2 after 40,000 h of use. To further improve the electrical conductivity of the thermally grown oxide on stainless steels, the Co layer was deposited on the stainless steel by means of an electroless deposition method; it was then thermally oxidized to obtain the Co3O4 layer, which is a highly conductive layer. With the increase of the Co coating thickness, the ASR value decreased. For Co deposited STS444 with 2 μmhickness, the measured ASR at 800˚ after 300 h oxidation is around 10 mΩcm2, which is lower than that of the STS446M, which alloy has a lower ASR value than that of the non-coated STS. The reason for this improved high temperature conductivity seems to be that the Mn is efficiently diffused into the coating layer, which diffusion formed the highly conductive (Mn,Co)3O4 spinel phases and the thickness of the Cr2O3(S), which is the rate controlling layer of the electrical conductivity in the SOFC environment and is very thin

Ni-GDC (gadolinia-doped ceria) composite powders, the anode material for the application of solid oxide fuel cells, were prepared by a solution reduction method using hydrazine. The distribution of Ni particles in the composite powders was homogeneous. The Ni-GDC powders were sintered at 1400˚C for 2 h and then reduced at 800˚C for 24 h in 3% H2. The percolation limit of Ni of the sintered composite was 20 vol%, which was significantly lower than these values in the literature (30-35 vol%). The marked decrease of percolation limit is attributed to the small size of the Ni particles and the high degree of dispersion. The hydrazine method suggests a facile chemical route to prepare well-dispersed Ni-GDC composite powders.

SOFC (Solid Oxide Fuel Cell) Ni-YSZ anode was fabricated by the spark plasma sintering (SPS) process and its microstructure and electrical properties were investigated in this study. The spark plasma sintering process was carried out at for holding time of 5 min under 40 MPa. To fabricate Ni-YSZ anode, the SPS processed specimens were reduced at under atmosphere. The reduced specimens showed relative density of according to sintering temperature. And also, the electrical conductivity of reduced specimens after sintering at 900 and showed (S/cm) values at the measuring range of .

SOFC용 L a0.68Ca/ sub 0.32/C r0.97 O3분말은 수산염법에 의해 제조되었고, 이 합성된 분말을 이용한 슬러리의 최적제조조건과 그린 필름의 최적 소성조건을 얻었으며,이 제조 조건에서 소결 시간과 온도에 따라 제조된 연결재료의 결정구조, 미세구조 및 소결거동을 각각X-선 회절, 주사전자현미경 그리고 에너지 분산 분광계를 이용하여 조사하였다. L a0.68C a0.32C r0.97 O3의 저온소결은 Cam (Cr O4)n에 의해 이루어졌음이 관찰되었고, 이때 Cam (Cr O4)n은 불규칙하게 녹아서 L a1-xC axCr O3-δ/와 반응하고 이 현상이 질량 이동을 증가시켜 시편의 급격한 결정립 성장과 조밀화를 야기시켰다. 이러한 결정립 성장과 조밀화는 소결온도 1400˚C부터 일어났다.X>부터 일어났다.

평판형 고체산화물 연료전지용 연결재료로 사용되는 La0.68Ca0.32Cr0.97O3박막의 소결조건을 변화시키며 곡강도, 상대밀도 및 전기전도도를 측정하였다. 그 결과 La0.68Ca0.32Cr0.97O3의 곡강도는 소결온도와 소결시간이 증가할수록 증가하였고, 상대밀도는 1400˚C, 5시간이상 소결한 시편에서 94%이상을 얻었다. La0.68Ca0.32Cr0.97O3의 저온소결은 Cam(CrO4)n에 의해 이루어졌음이 관찰되었다. 또한 La0.68Ca0.32Cr0.97O3의 전기전도도는 1400˚C, 7시간 소결한 시편의 경우 1000˚C에서 약 100/cm이상을 얻었다.