• Title, Summary, Keyword: carbon electrode

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Electrochemical Enhancement of Carbon Felt Electrode for Vanadium Redox Flow Battery with Grephene Oxide (산화그레핀을 이용한 바나듐레독스흐름전지용 카본펠트전극의 표면개질을 통한 전기화학적 활성개선)

  • LEE, KEON JOO;KIM, SUNHOE
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.2
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    • pp.206-211
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    • 2017
  • Carbon felt electrode for the vanadium redox-flow battery (VRFB) has been studied to see the effect of grephene oxide (GO) treatment on the surface of the carbon felt electrode. In this paper, surface of carbon felt electrodes were treated with various concentrations of grephene oxide. Electrochemical analysis, cyclic voltammetry (CV), was performed to investigate redox characteristics as electrode for VRFB. Also the effect of GO on the introduction of functional group on the surface of carbon felt electrodes were investigated using X-ray photoelectron spectroscopy (XPS), which discovered increase in the overall functional group content on the surface of carbon felts.

Synergistic Effect of the MnO Catalyst and Porous Carbon Matrix for High Energy Density Vanadium Redox Flow Battery (고에너지 밀도 바나듐 레독스 흐름 전지를 위한 망간산화물 촉매와 다공성 탄소 기재의 시너지 효과)

  • Kim, Minsung;Ko, Minseong
    • Journal of the Korean institute of surface engineering
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    • v.52 no.3
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    • pp.150-155
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    • 2019
  • The carbon electrode was modified through manganese-catalyzed hydrogenation method for high energy density vanadium redox flow battery (VRFB). During the catalytic hydrogenation, the manganese oxide deposited at the surface of the carbon electrode stimulated the conversion reaction from carbon to methane gas. This reaction causes the penetration of the manganese and excavates a number of cavities at electrode surface, which increases the electrochemical activity by inducing additional electrochemically active site. The formation of the porous surface was confirmed by the scanning electron microscopy (SEM) images. Finally, the electrochemical performance test of the electrode with the porous surface showed lower polarization and high reversibility in the cathodic reaction compared to the conventional electrode.

Electro-Catalytic Oxidation of Amoxicillin by Carbon Ceramic Electrode Modified with Copper Iodide

  • Karim-Nezhad, Ghasem;Pashazadeh, Ali;Pashazadeh, Sara
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.322-328
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    • 2013
  • Copper iodide was employed as a modifier for preparation of a new carbon ceramic electrode. For the first time, the catalytic oxidation of amoxicillin (AMX) was demonstrated by cyclic voltammetry, chronoamperometry and amperometry methods at the surface of this modified carbon ceramic electrode. The copper iodide modified sol-gel derived carbon ceramic (CIM-SGD-CC) electrode has very high catalytic ability for electrooxidation of amoxicillin. The catalytic oxidation peak current was linearly dependent on the amoxicillin concentration and the linearity range obtained was 100 to 1000 ${\mu}mol\;L^{-1}$ with a detection limit of 0.53 ${\mu}mol\;L^{-1}$. The diffusion coefficient ($D=(1.67{\pm}0.102){\times}10^{-3}\;cm^2\;s^{-1}$), and the kinetic parameter such as the electron transfer coefficient (${\alpha}$) and exchange current density ($j_0$) for the modified electrode were calculated. The advantages of the modified CCE are its good stability and reproducibility of surface renewal by simple polishing, excellent catalytic activity and simplicity of preparation.

Carbon and Silver Electrode Properties of Power Electroluminescent Device (후막 전계 발광 소자의 Carbon과 Silver 전극 특성)

  • Lee, Jong-Chan;Sung, Hyun-Ho;Cho, Whang-Sin;Park, Yong-Kyu;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.26-30
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    • 2000
  • In this paper, carbon and silver electrode properties of power electroluminescent device were investigated. Devices were manufactured by screen-printing and manufactured devices were measured following things with variable applied voltage; emission spectra, transferred charge density, brightness and current. A continuous test at $65 ^{\circ}C$ of temperature and 95% of humidity was operated. The brightness of devices which were made of silver and carbon electrode at 100V was $67.03cd/m^2$ and $60.02cd/m^2$ respectively. In case of device, which was made of silver electrode, a black spot was formed after 72 hours and degraded but carbon electrode was stable.

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Characteristics of DMFC Using High Porous Active Carbon as an Uncatalysed Diffusion Layer in Anode Electrode

  • Jung, Doo-Hwan;Shin, Dong-Ryul
    • Carbon letters
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    • v.1 no.1
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    • pp.27-30
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    • 2000
  • Performance of direct methanol fuel cell using high porous active carbon as an uncatalysed diffusion layer in anode (composite electrode) has been evaluated. Effects of porous active carbon in anode were investigated by galvanostatic method and Fourier Transform Infrared spectroscopy. The single cell was operated with 2.5 M methanol at temperature of $80-120^{\circ}C$ and showed performance of $210-510\;mA/cm^2$ at 0.4V. By replacing conventional electrode with composite electrode, the increment of $290\;mA/cm^2$ in current density was obtained at $90^{\circ}C$and 0.4V. The potential decay of the single cell was about 14.5% for 20 days operation.

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Analysis of Transient Response Behavior and Frequency-Dependent Ground Impedances of the Carbon Ground Electrodes (탄소접지극 접지임피던스의 주파수의존성과 과도응답특성의 해석)

  • Lee, Bok-Hee;Lee, Kang-Soo;Kim, You-Ha;Um, Sang-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.2
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    • pp.54-61
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    • 2013
  • This paper presents transient response behavior and frequency-dependent ground impedance of a single carbon ground electrode. The ground impedance of the carbon ground electrode was measured as a function of frequency of injected currents and simulated by using the distributed parameter circuit model with due regard to the frequency-dependent soil parameters, and the transient response behavior of the carbon ground electrode against impulse currents were investigated. As a consequence, the frequency-dependent ground impedance of the carbon ground electrode showed the capacitive behavior, that is, the ground impedance decreases with increasing the frequency of injected currents and lowers at the fast front time of impulse current. It was found that the carbon ground electrode is effective in grounding system for lightning protection. The ground impedance simulated with due regard to the frequency-dependent soil parameters was in good agreement with the measured data. The adequacy of the simulation technique and the distributed parameter circuit model for the carbon ground electrode was verified. It is expected that the simulation methodology, which analyzes the frequency-dependent ground impedance of the carbon ground electrode proposed in this work, can be used in the design of a grounding system for protection against lightning.

Properties of Carbon Pastes Prepared with Mixing Ratios of Nano Carbon and Graphite Flakes

  • Kim, Kwangbae;Song, Ohsung
    • Korean Journal of Materials Research
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    • v.28 no.11
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    • pp.615-619
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    • 2018
  • To produce carbon electrodes for use in perovskite solar cells, electrode samples are prepared by mixing various weight ratios of 35 nm nano carbon(NC) and $1{\mu}m$ graphite flakes(GF), GF/(NC+GF) = 0, 0.5, 0.7, and 1, in chlorobenzene(CB) solvent with a $ZrO_2$ binder. The carbon electrodes are fabricated as glass/FTO/carbon electrode devices for microstructure characterization using transmission electron microscopy, optical microscopy, and a field emission scanning electron microscopy. The electrical characterization is performed with a four-point probe and a multi tester. The microstructure characterization shows that an electrode with excellent attachment to the substrate and no surface cracks at weight ratios above 0.5. The electrical characterization results show that the sheet resistance is <$70{\Omega}/sq$ and the interface resistance is <$70{\Omega}$ at weight ratios of 0.5 and 0.7. Therefore, a carbon paste electrode with microstructure and electrical properties similar to those of commercial carbon electrodes is proposed with an appropriate mixing ratio of NC and GF containing a CB solvent and $ZrO_2$.

Electrochemical Performance of Carbon-PTFE Electrode with High Capacitance and Density for EDLC (EDLC용 고용량, 고밀도 Carbon-PTFE 전극의 전기화학적 특성)

  • Kim, Ick-Jun;Jeon, Min-Je;Yang, Sun-Hye;Moon, Seong-In;Kim, Hyun-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.541-542
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    • 2006
  • This work describes the effect of the number of roll pressing and the composition of carbon black on the electric and mechanical properties of carbon-PTFE electrode, in which composition is MSP 20 : carbon black : PTFE = 95-X : X : 5 wt.%. It was found that the best electric and mechanical properties were obtained for sheet electrode roll pressed about 15 times and for sheet electrode, in which composition is MSP 20 : carbon black : PTFE = 80 : 15 : 5 wt.%. These behaviors could be explained by the network structure of PTFE fibrils and conducting paths linked with carbon blacks, respectively. On the other hand, cell capacitor using the sheet electrode with 15 wt.% of carbon black attached on aluminum current collector with the electric conductive adhesive, in composition is carbon black : CMC = 70 : 30 wt.%, has exhibited the best rate capability between $0.5mA/cm^2{\sim}100mA/cm^2$ current density and the lowest ESR.

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Study of Parameters on the Electrochemical Properties of Carbon-PTFE Electrode for Electric Double Layer Capacitor (EDLC용 Carbon-PTFE 전극의 전기화학적 특성에 미치는 변수 연구)

  • Kim, Ick-Jun;Yang, Sun-Hye;Jeon, Min-Je;Moon, Seong-In;Kim, Hyun-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.355-356
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    • 2006
  • This work describes the effect of the number of roll pressing and the composition of carbon black on the electric and mechanical properties of carbon-PTFE electrode, in which composition is MSP20 : carbon black: PTFE = 95-X : X : 5 wt.%. It was found that the best electric and mechanical properties were obtained for sheet electrode roll pressed about 15 times and for sheet electrode, in which composition is MSP20 carbon black : PTFE = 80 : 15 : 5 wt%. These behaviors could be explained by the network structure of PTFE fibrils and conducting paths linked with carbon blacks, respectively. On the other hand, cell capacitor using the sheet electrode with 15 wt.% of carbon black attached on aluminum current collector with the electric conductive adhesive, in composition is carbon black : CMC = 70 : 30 wt.%, has exhibited the best rate capability between 0.5 $mA/cm^2$ ~ 100 $mA/cm^2$ current density and the lowest ESR.

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Porous Electrode manufacture by catalyst powdering method for PAFC (촉매분말법에 의한 PAFC용 다공성 전극제작)

  • 김영우;이주성
    • Journal of Energy Engineering
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    • v.2 no.2
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    • pp.194-199
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    • 1993
  • Gas diffusion passes are introduced to catalyst layer so as to enlarge reaction region in cathode and anode and then improve electrode performances. The catalyst layer was manufactured with PTFE/carbon (none catalyst loaded) for gas diffusion and Pt/carbon (10 w/o Pt catalyst loaded) by varing the mixing ratio of (PTFE/carbon) to (Pt/carbon) by catalyst powdering method. The electrodes made by mixing Pt(10 w/o)/carbon powders and PTFE/carbon powders containing 60 w/o PTFE at the ratio of 7 : 3 showed the best electrode performances. It was known that by comparing the porosities to electrode performances the electrode performances were increased as both macro pore for gas diffusion and micro pore for electrolyte intrusion were formed much more. The platinum catalyst content in electrode was 0.2 mg/$\textrm{cm}^2$ and the PTFE content was 42 w/o. The electrode performance in unit cell was 220 ㎃/$\textrm{cm}^2$/0.7 V at operating temperature of 150$^{\circ}C$.

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