• Title/Summary/Keyword: Anode Characteristics

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Electrode Fabrication of Molten Carbonate Fuel Cell Anode (용융탄산염형 연료전지의 anode 전극 제작)

  • Kim, G.Y.;Moon, S.I.;Yun, M.S.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.255-258
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    • 1991
  • MCFC are expected as an electric and thermal power source of the urban cogenerating system because MCFC have higher electric power efficiency and better thermal power quality. However, the MCFC which use strorgly corrosive molten Carbonate at $650^{\circ}C$ have many problems. Material issues with the molten carbonate fuel cell in clude anode creep, conthode dissolution and bipolar plate corrosion. The objectives of this study are to examied fabrication process and characteristics of anode electrode.

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Effect of the LiF anode interfacial layer on polymer light emitting diodes

  • Sohn, Sun-Young;Lee, Dae-Woo;Park, Keun-Hee;Jung, Dong-Geun;Kim, H.M.;Manna, U.;Yi, J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1056-1058
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    • 2005
  • Electrical and optical characteristics of MEH-PPV-based PLEDs with the LiF anode interfacial layer were investigated. The maximum luminance efficiency of the device with a LiF anode interfacial layer of 1-nm-thick was 3.0 lm/W, which is higher than 1.97 lm/W of the device without a LiF layer. By inserting LiF, excess injected holes from ITO anode can be blocked and hence the recombination ratio of electrons and holes can be increased in the emitting layer to improve device efficiency.

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Development of Tubular Solid Oxide Fuel Cell (원통형 고체산화물 연료전지 기술개발)

  • Song, Rak-Hyun
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.373-380
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    • 2001
  • Solid Oxide Fuel Cells (SOFCs) have received considerable attention because of the advantages of high effiiciency, low pollution, cogeneration application and excellent integration with simplified reformer In this paper, we reported development of anode-tubular SOFC by wet process. For making tubular cell, Ni-cermet YSZ anode tube was fabricated using extrusion process, and YSZ electrolyte layer and LSM-YSZ composite, LSM, LSCF cathode layer were coated onto the anode supported tube using slurry dipping process and sintered by co-firing process. By using this tubular cell, we fabricated single cell consisted of the various cathode layers and 4 cell stack with an effective area of $75 cm^2$ per single cell, and evaluated their performance characteristics.

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Numerical Analyses on Snapback-Free Shorted-Anode SOI LIGBT by using a Floating Electrode and an Auxiliary Gate (플로우팅 전극과 보조 게이트를 이용하여 스냅백을 없앤 애노드 단락 SOI LIGBT의 수치 해석)

  • O, Jae-Geun;Kim, Du-Yeong;Han, Min-Gu;Choe, Yeon-Ik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.2
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    • pp.73-77
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    • 2000
  • A dual-gate SOI SA-LIGBT (shorted-anode lateral insulated gate bipolar transistor) which eliminates the snapback effectively is proposed and verified by numerical simulation. The elimination of the snapback in I-V characteristics is obtained by initiating the hole injection at low anode voltage by employing a dual gate and a floating electrode in the proposed device. For the proposed device, the snapback phenomenon is completely eliminate, while snapback of conventional SA-LIGBT occurs at anode voltage of 11 V. Also, the drive signals of two gates have same polarity by employing the floating electrode, thereby requiring no additional power supply.

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Prevention of Crevice Corrosion of STS 304 Stainless Steel by a Mg-alloy Galvanic Anode

  • Lim, U.J.;Yun, B.D.;Kim, J.J.
    • Corrosion Science and Technology
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    • v.5 no.3
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    • pp.90-93
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    • 2006
  • Prevention of crevice corrosion was studied for STS 304 stainless steel using a Mg-alloy galvanic anode in solutions with various specific resistivity. The crevice corrosion and corrosion protection characteristics of the steel was investigated by the electrochemical polarization and galvanic corrosion tests. Experimental results show that the crevice corrosion of STS 304 stainless steel does not occur in solutions of high specific resistivity, but it occurs in solutions of low specific resistivity like in solutions with resistivities of 30, 60 and $115{\Omega}{\cdot}m$. With decreasing specific resistivity of the solution, the electrode potential of STS 304 stainless steel in the crevice is lowered. The potential of STS 304 stainless steel in the crevice after coupling is cathodically polarized more by decreasing specific resistivity indicating that the crevice corrosion of STS 304 stainless steel is prevented by the Mg-alloy galvanic anode.

Development of High-Sensitivity Ion Sources for Residual Gas Analyzer

  • Park, Chang-Jun;Han, Cheol-Su;An, Sang-Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.104.2-104.2
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    • 2013
  • A residual gas analyzer (RGA) system has been developed in this laboratory. Characteristics of the RGA system parts such as ion source, quadrupole mass filter and sensitivity are introduced. Some efforts have been made to improve performance of the two types of ion sources, open ion source (OIS) and closed ion source (CIS). A metal mesh was placed onto the electron beam entrance of the CIS anode tube to block the filament field penetration. Sensitivity of the CIS ion sources with and without the mesh was compared by mass spectra of SF6 gas (97% He base) introduced into the CIS anode through a needle valve. About ten-times improvement in the RGA sensitivity was observed for the CIS with the mesh in the electron entrance. Computer simulation showed an axi-symmetric anode potential distribution and improved focusing of the electron beam inside the anode tube with the mesh.

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Effect of Lithium Contents and Applied Pressure on Discharge Characteristics of Single Cell with Lithium Anode for Thermal Batteries (리튬 함량 및 단위 셀 압력이 열전지용 리튬 음극의 방전 성능에 미치는 영향)

  • Im, Chae-Nam;Ahn, Tae-Young;Yu, Hye-Ryeon;Ha, Sang Hyeon;Yeo, Jae Seong;Cho, Jang-Hyeon;Yoon, Hyun-Ki
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.2
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    • pp.165-173
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    • 2019
  • Lithium anodes (13, 15, 17, and 20 wt% Li) were fabricated by mixing molten lithium and iron powder, which was used as a binder to hold the molten lithium, at about $500^{\circ}C$ (discharge temp.). In this study, the effect of applied pressure and lithium content on the discharge properties of a thermal battery's single cell was investigated. A single cell using a Li anode with a lithium content of less than 15 wt% presented reliable performance without any abrupt voltage drop resulting from molten lithium leakage under an applied pressure of less than $6kgf/cm^2$. Furthermore, it was confirmed that even when the solid electrolyte is thinner, the Li anode of the single cell normally discharges well without a deterioration in performance. The Li anode of the single cell presented a significantly improved open-circuit voltage of 2.06 V, compared to that of a Li-Si anode (1.93 V). The cut-off voltage and specific capacity were 1.83 V and $1,380As\;g^{-1}$ (Li anode), and 1.72 V and $1,364As\;g^{-1}$ (Li-Si anode). Additionally, the Li anode exhibited a stable and flat discharge curve until 1.83 V because of the absence of phase change phenomena of Li metal and a subsequent rapid voltage drop below 1.83 V due to the complete depletion of Li at the end state of discharge. On the other hand, the voltage of the Li-Si anode cell decreased in steps, $1.93V{\rightarrow}1.72V(Li_{13}Si_4{\rightarrow}Li_7Si_3){\rightarrow}1.65V(Li_7Si_3{\rightarrow}Li_{12}Si_7)$, according to the Li-Si phase changes during the discharge reaction. The energy density of the Li anode cell was $807.1Wh\;l^{-1}$, which was about 50% higher than that of the Li-Si cell ($522.2Wh\;l^{-1}$).

Mechanical and Electrical Performance of Anode-Supported Solid Oxide Fuel Cells during Thermal Cyclic Operation (열 사이클에 따른 고체산화물 연료전지의 기계적 및 전기적 특성)

  • Yang, Su-Yong;Park, Jae-Keun;Lee, Tae-Hee;Yu, Jung-Dae;Yoo, Young-Sung;Park, Jin-Woo
    • Journal of the Korean Ceramic Society
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    • v.43 no.12 s.295
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    • pp.775-780
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    • 2006
  • Mechanical and electrical performance of anode-supported SOFC single cells were analyzed after thermal cyclic operation. The experiments of thermal cyclic cell-operation were carried out four times and performance of each cell was measured at different temperatures of 650, 700, and $750^{\circ}C$, respectively. As increasing the number of thermal cycle test, single cells showed poor I-V characteristics and lower 4-point bending strength. The anode polarization was also measured by AC-impedance analysis. The observation of the microstructure of the anodes in single cells proved that the average particle size of Ni decreased and the porosity of anode increased. It is thought that the thermal cycle caused the degradation of performance of single cells by reducing the density of three-phase boundary region.

Optimization of Condensate Water Drain Logic Depending on the Characteristics of Drain Valve in FPS of Fuel Cell Vehicle and Development of Anode Water Management Strategy to Achieve High Fuel Efficiency and Operational Stability (연료전지 자동차 내 수소 공급 시스템에서 드레인 밸브 특성에 따른 드레인 로직 최적화 및 연비와 운전안정성을 고려한 물 관리 전략 개발)

  • AHN, DEUKKUEN;LEE, HYUNJAE;SHIM, HYOSUB;KIM, DAEJONG
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.2
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    • pp.155-162
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    • 2016
  • A proton exchange membrane fuel cell (PEMFC) produces only water at cathode by an electrochemical reaction between hydrogen and oxygen. The generated water is transported across the membrane from the cathode to the anode. The transported water collected in water-trap and drained to the cathode within the humidifier outlet. If the condensate water is not being drained at the appropriate time, condensate water in the anode can cause the performance degradation or fuel efficiency degradation of fuel cell by the anode flooding or unnecessary hydrogen discharge. In this study, we proposed an optimization method of condensate water drain logic for the water drain performance and the water drain algorithm as considered the condensate water generating speed prep emergency case. In conclusion, we developed the water management strategy of fuel processing system (FPS) as securing fuel efficiency and operating stability.

Design of a 94-GHz Single Balanced Mixer Using Planar Schottky Diodes with a Nano-Dot Structure on a GaAs Substrate

  • Uhm, Won-Young;Ryu, Keun-Kwan;Kim, Sung-Chan
    • Journal of information and communication convergence engineering
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    • v.14 no.1
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    • pp.35-39
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    • 2016
  • In this paper, we develop a 94-GHz single balanced mixer with low conversion loss using planar Schottky diodes on a GaAs substrate. The GaAs Schottky diode has a nanoscale anode with a T-shaped disk that can yield high cutoff frequency characteristics. The fabricated Schottky diode with an anode diameter of 500 nm has a series resistance of 21 Ω, an ideality factor of 1.32, a junction capacitance of 8.03 fF, and a cutoff frequency of 944 GHz. Based on this technology, a 94-GHz single balanced mixer was constructed. The fabricated mixer shows an average conversion loss of -7.58 dB at an RF frequency of 92.5 GHz to 95 GHz and an IF frequency of 500 MHz with an LO power of 7 dBm. The RF-to-LO isolation characteristics were greater than -32 dB. These values are considered to be attributed to superior Schottky diode characteristics.