• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2001년도 춘계총회 및 학술발표회
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• pp.37-37
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• 2001

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2005년도 춘계총회 및 학술발표회
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• pp.21-21
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• 2005

• 한국세라믹학회지
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• 제36권5호
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• pp.521-530
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• 1999

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.261-264
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• 2000

The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li polymer battery. This paper describes temperature dependence of conductivity, impedance spectroscopy, electrochemical properties of PAN/PVDF electrolytes as a function of a mixed ratio. PAN/PVDF based polymer electrolyte films were prepared by thermal gellification method of preweighed PAN/PVDF, plasticizer and Li salt. By adding PVDF and as a function of plasticizer mixed ratio to PAN-LiClO4 electrolyte, its conductivity was higher than that of PAN-$LiClO4_4$ electrolyte. The conductivity of PAN/PVDF electrolytes was $10^{-3}S/cm$. $10PAN10PVDFLiClO_4PC_5EC_5$ electrolyte shows the better conductivity of the others. Steady state current method and ac impedance used for the determination of transference numbers in PAN/PVDF electrolyte film. The transference number of $10PAN10PVDFLiClO_4PC_5EC_5$ electrolyte is 0.45.

• 한국전기전자재료학회논문지
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• 제35권2호
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• pp.194-198
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• 2022

All-solid-state thin-film battery can realize the integration of electronic circuits into small devices. However, a high voltage cathode material is required to compensate for the low energy density. Therefore, it is necessary to study all-solid-state thin-film battery based on the high voltage cathode material LNMO. Nevertheless, the electrochemical properties deteriorate due to the problem of the interface between LiNi_0.5Mn_1.5O₄ (LNMO) and the solid electrolyte LiPON. In this study, to solve this problem, amorphous V₂O₅ was deposited as an interlayer between LNMO and LiPON. We confirmed the possibility of improving cycle performance of LNMO based thin-film battery. We expect that the results of this study can extend the battery lifespan of small devices using LNMO based all-solid-state thin-film battery.

• 한국재료학회지
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• 제9권8호
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• pp.792-797
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• 1999

고체 산화물 연료전지의 전해질로 주로 사용되는 8mol.%$Y_2$$O_3$-$ZrO_2$는 전기 전도성은 우수하나 기계적 특성이 좋지 못하므로, 전기적 특성과 기계적 특성이 동시에 우수한 고체산화물 연료전지의 전해질의 개발이 요구되고 있다. 본 연구는 이러한 두 가지 요구조건을 충족시키기 위해서 수행되어졌다. 단위전지의 공기극 재료인 LSM(La(sub)0.75Sr(sub)0.25MnO$_3$) 기판과 Si wafer를 기판으로 기계적 성질이 우수한 3mol.%의 YSZ(3-YSZ)와 전기 전도성이 우수한 8mol.%의 YSZ(8-YSZ)를 각각 단층 및 다층 박막의 네 가지 형태로 전자빔 코팅에 의해 전해질 막을 제작하였다. 박막층의 분석결과, 결정조직은 증착된 3-YSZ 박막의 정방정 및 일부 단사정 구조, 8-YSZ 박막은 입방정 구조의 결정성이 나타났다. 단층막 보다 다층막이 낮은 내부 응력을 보였으며, 다층막이 기존의 8-YSZ 단층막의 열처리 전, 후와 비슷한 미세 경도 값을 보였다.

• 센서학회지
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• 제17권4호
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• pp.273-280
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• 2008

Monolith aperture-type oxygen sensors with simple structure of YSZ(pin-hole)/Pt/ YSZ(solid electrolyte)/Pt were fabricated by co-firing technique. To enhance the yield of productivity, a couple of YSZ green sheets for diffused barrier and solid electrolyte were prepared by tape-casting and co-firing method. The limit current characteristics of the oxygen sensors were measured between 500 and $650^{\circ}C$ The heating temperature of $600^{\circ}C$ was optimum as a portable oxygen sensor in the range of oxygen concentration from 0 to 75 vol%. Linear proficiency of limit current behavior as a function of oxygen concentration was controlled by the variation of aperture dimension. The fabricated oxygen sensors showed the stable sensing output for 30 days. Gas leakage in bonding area due to warping, cracking and thermal cycling was not found in the period.

• 한국세라믹학회지
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• 제36권4호
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• pp.391-402
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• 1999

Characteristics of composite electrolytes which were prepared by coating a thin film of YSZ (yttria sta-bilized zirconia : (ZrO2)0.92 (Y2O3)0.08) on YDC (yttria doped ceria : Ce0.8Y0.2O1.9) with mixed conductivity have been investigated in order to develop the low-temperature solid oxide fuel cell. The thickness (t) of spin-coated YSZ thin films after the heat-treatment at 600$^{\circ}C$ was increased proportionally to the sol con-centrations (C) while the decrease in its thickness with the spin rate ($\omega$) could be expressed in the e-quation of ln t=9.49-0.53 ln $\omega$(0.99mol//s sol conc.) When the sol concentration and the spin rate being less than 0.99 mol/l and higher than 1000 rpm respectively reliable YSZ/YDC composite electrolytes could be obtained by multi-coating although several micro-cracks were observed in singly coated YSZ film surfaces. The dense YSZ film with a 1$\mu\textrm{m}$ thickness was prepared by coating of 0.99 mol/l YSZ sol five-times at 2000 rpm followed by heat-treatment at 1400$^{\circ}C$ for 2h, The adhesion between YSZ film and YDC substrate was found to be very good. The open circuit voltages of H2/O2 single cell with YSZ/YDC composite electrolytes were 0.79∼0.82 V at 800$^{\circ}C$ and 0.75∼0.77V at 900$^{\circ}C$ The open circuit voltage was inversely proportioned to the thickness ratio of YSZ thin film (1$\mu\textrm{m}$) to YDC substrate(0.28-2.22 mm)

• 한국세라믹학회지
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• 제56권2호
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• pp.130-145
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• 2019

Widespread commercialization of solid oxide fuel cells (SOFCs) is expected to be realized in various application fields with the advent of cost-effective fabrication of cells and stacks in high volumes. Cost-reduction efforts have focused on production yield, power density, operation temperature, and continuous manufacturing. In this article, we examine several issues associated with processing for SOFCs from the standpoint of the bimodal packing model, considering the external constraints imposed by rigid substrates. Optimum compositions of composite cathode materials with high volume fractions of the second phase (particles dispersed in matrix) have been analyzed using the bimodal packing model. Constrained sintering of thin electrolyte layers is also discussed in terms of bimodal packing, with emphasis on the clustering of dispersed particles during anisotropic shrinkage. Finally, the structural transition of dispersed particle clusters during constrained sintering has been correlated with the structural stability of thin-film electrolyte layers deposited on porous solid substrates.

• 전기화학회지
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• 제15권1호
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• pp.19-26
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• 2012

표준 전해액에 2중량%의 VC(vinylene carbonate)와 FEC(fluoroethylene carbonate)를 각각 첨가한 전해액으로부터 흑연 음극 표면에 SEI(solid electrolyte interphase) 층을 형성시키고, SEI 특성에 따른 흑연 음극의 저온($-30^{\circ}C$) 충방전 특성을 조사하였다. 흑연의 충 방전 용량은 FEC를 첨가한 전해액, 표준 전해액, 그리고 VC를 첨가한 전해액의 순서로 감소하였고, 충 방시 발생하는 과전압은 반대경향을 보이며 증가하였다. 이는 첨가제의 종류에 따라 생성된 SEI 층의 저항과 전하전달저항에 차이가 있음을 설명하는데, 이를 SEI 층의 화학 조성과 두께를 비교하여 확인하였다. 표준 전해액으로부터 생성된 SEI 층은 C-O 성분을 포함하는 고분자 형태의 화합물과 리튬 염의 환원분해로 생성된 $Li_xPF_yO_z$ 등으로 구성되었다. VC를 포함한 전해액으로부터 생성된 SEI 층은 C-O 화합물 비율이 높고 조밀하여 리튬 염의 분해가 억제되어 얇은 피막이 생성됨에도 불구하고 가장 큰 저항 값을 보였다. 반면에 FEC로부터 생성된 SEI 층은 C-O 성분의 비율이 VC를 첨가한 전해액의 경우보다는 작으면서도 리튬 염의 분해가 크지 않아서, 리튬 이온의 이동이 가장 용이한 피막을 형성하고 있어 가장 낮은 피막저항 및 전하전달 저항을 나타내었다. 결론적으로 FEC를 첨가제로 사용한 경우 생성된 SEI 층의 저항이 가장 작아서 흑연 음극의 저온특성이 가장 우수하였다.