• 제목/요약/키워드: Cathodes

검색결과 269건 처리시간 0.028초

중 저온형 고체 산화물 연료전지를 Co-Mn 계열의 페로브스카이트 구조의 공기극에 관한 연구 (Studies of Co-Fe based perovskite cathodes with fixed A-site cations)

  • 박광진;김정현;배중면
    • 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.

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Characterization of CNT-ink and fabrication of a cold cathode using jet-printing technique.

  • Lee, Dae-Sik;Lim, Seong-Chu;Lee, Young-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1532-1534
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    • 2008
  • Aquesous carbon nanotubes (CNTs) solutions were prepared using SDS (sodium dodecyl sulfonate) and NADDBS (sodium dodecylbenzene sulfonate). Our inks are found to have the viscosity of 1-2 cps. In addition, the surface tension of inks inversely decreased with increasing surfactant concentration and then saturated at critical micelle concentration (CMC). The low surface tension at CMC gave rise to lower contact angles on Indium layers, resulting in larger printable feature sizes. In the fabrication of cold cathode, jet-printing is feasible to modify and scale up the cathode structures. These feasibilities could contribute jet-printing method to be more adaptable for making large-area cold cathodes.

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A Robust Process for the Fabrication of Field Emission Backlights

  • Marquardt, B.;Cojucaru, C.S.;Xavier, S.;Legagneux, P.;Pribat, D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1606-1609
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    • 2008
  • In this paper, we present a novel process for the realization of large area, low cost field emission cathodes. The process makes use of alumina substrates, which are anodically oxidized in order to yield porous structures capable of hosting metal catalyst nanoparticles. By carefully controlling the final stage of the anodisation as well as the electrodeposition conditions, it is possible to fine tune the density of such catalysts in the range of $10^8-10^9/cm^2$. The catalytic growth of CNTs is subsequently performed at low temperature (${\sim}\;600^{\circ}C$ or below, thanks to the use of $H_2O$), using plasma enhanced chemical vapour deposition. There is no lithography need to make the cathode and current densities of ${\sim}\;1mA/cm^2$ are easily obtained.

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Alq$_3-based$ Organic Light-Emitting Devices with Al/NaF cathodes: Performance Enhancement and Interface Electronic Structures

  • Park, Y.;Lee, J.;Kim, D.Y.;Chu, H.Y.;Lee, H.;Do, L.M.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.25-27
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    • 2003
  • The device characteristics and the interface electronic structures of organic light-emitting devices based on /tris-(8-hydroxyquinoline)aluminum ($Alq_3$) were investigated with Al/NaF cathode. The Al/NaF cathode greatly improved the performance of the device over the Al-only cathode. A series of photoelectron spectroscopy studies on cathode structures including Al/LiF and $Al/CaF_2$ revealed that the performance enhancement originated mainly from the HOMO peak shift upon the fluoride deposition rather than the formation of the gap states

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Improved High Rate Capabilities of Composite Cathodes for Lithium Ion Batteries

  • Lee, Sang-Young;Jeong, Yeon-Uk
    • 전기화학회지
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    • 제11권4호
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    • pp.309-312
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    • 2008
  • In an attempt to achieve high rate capability of cell, a new composite cathode was prepared by mixing host compounds with MWCNTs and Super P carbon. Because MWCNTs generally have bundle-type morphologies, it is not easy to get completely separated form. Successful dispersion of divided small bundles between the host particles keeps electrochemical contacts among the particles and plays a significant role in the buffer action as a volume-change absorber. Relative amounts and distributions of the additives are important for design of the electrode for high power application of lithium ion batteries.

Hydrothermally Synthesized TiO2 Nanoparticles as a Cathode Catalyst Material in Lithium-Oxygen Batteries

  • Kang, Seung Ho;Song, Kyeongse;Jung, Jaepyeong;Jo, Mi Ru;Khan, M. Alam;Kang, Yong-Mook
    • Journal of Electrochemical Science and Technology
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    • 제5권2호
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    • pp.45-48
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    • 2014
  • $TiO_2$ nanoparticles (NPs) with a diameter of 100 nm were synthesized by a simple hydrothermal route at $220^{\circ}C$ and then processed for a possible alternate cathode catalyst material in the lithium-oxygen batteries. It was found that when $TiO_2$ nanoparticles were utilized as cathodes, substantial improvements in the discharge capacity, cycle ability, rate capability and low overpotential were observed. This can be attributed to its high catalytic activity and large surface area.

Hydrothermally Synthesized TiO2 Nanoparticles as a Cathode Catalyst Material in Lithium-Oxygen Batteries

  • Kang, Seung Ho;Song, Kyeongse;Jung, Jaepyeong;Jo, Mi Ru;Khan, M. Alam;Kang, Yong-Mook
    • Journal of Electrochemical Science and Technology
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    • 제5권4호
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    • pp.105-108
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    • 2014
  • $TiO_2$ nanoparticles (NPs) with a diameter of 100 nm were synthesized by a simple hydrothermal route at $220^{\circ}C$ and then processed for a possible alternate cathode catalyst material in the lithium-oxygen batteries. It was found that when $TiO_2$ nanoparticles were utilized as cathodes, substantial improvements in the discharge capacity, cycle ability, rate capability and low overpotential were observed. This can be attributed to its high catalytic activity and large surface area.

Penning 방전을 이용한 실리콘 CVD (Penning Discharge Assisted Chimical Vapor Deposition of Silicon)

  • 김태훈;이지화
    • 한국진공학회지
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    • 제5권1호
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    • pp.77-84
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    • 1996
  • Silicon deposition by Penning discharge was carried out using a mixture of 5% $SiH_4/H_2$ and Ar gas, and the effects of the deposition conditions(gas mixing raito, substrate temperature. discharge power etc.) on the growth rate, crystallinity and morphology of the films deposited were investigated. The magnetic field(800 G) confined the plasma in the region between the two cathodes and enhanced the discharge current by a factor of a few hundreds below 1 mTorr. The magnetic field-enhanced plasma density resulted in a very large deposition rate of about 300 $\AA$/min at $SiH_4$ flow rate of 0.7 sccm and the substrate temperature of $800^{\circ}C$. Characterization of the films by Raman spectroscopy, X-ray diffraction, and scanning electron microscopy revealed that an epitaxial film with a smooth surface grows above 80$0^{\circ}C$, an amorphous film below $400^{\circ}C$, and a rough polycrystalline film at intermediate temperatures.

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Study on electrochemical performances of sulfur-containing graphene nanosheets electrodes for lithium-sulfur cells

  • Son, Ki-Soo;Kim, Seok
    • Carbon letters
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    • 제15권2호
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    • pp.113-116
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    • 2014
  • Due to their morphology, electrochemical stability, and function as a conducting carbon matrix, graphene nanosheets (GNS) have been studied for their potential roles in improving the performance of sulfur cathodes. In this study, a GNS/sulfur (GNS/S) composite was prepared using the infiltration method with organic solvent. The structure, morphology and crystallinity of the composites were examined using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The electrochemical properties were also characterized using cyclic voltammetry (CV). The CV data revealed that the GNS/S composites exhibited enhanced specific-current density and ~10% higher capacity, in comparison with the S-containing, activated-carbon samples. The composite electrode also showed better cycling performance for multiple charge/discharge cycles. The improvement in the capacity and cycling stability of the GNS/S composite electrode is probably related to the fact that the graphene in the composite improves conductivity and that the graphene is well dispersed in the composites.

SIMULATION OF THIN-FILM FIELD EMITTER TRIODE

  • Park, Kyung-Ho;Lee, Soon-Il;Koh, Ken-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.651-654
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    • 2002
  • We carried out 2-dimensional numerical calculations of electrostatic potential for triode field emitters with planar cathodes using the finite element method. As it turned out, the conventional triode structure with a planar cathode suffered from large gate current and wide spreading of emitted electrons. To circumvent these shortcomings, we proposed a new triode structure. By simply inserting a conducting layer of proper thickness on top of the cathode layer, we were able to modify the electric field distribution on the cathode surface so that low gate current and electron-focusing effect were achieved, simultaneously.

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