• 제목, 요약, 키워드: carbon electrode

검색결과 1,228건 처리시간 0.046초

NaCl 전해질 농도 변화에 따른 다공질 탄소전극의 전기적 특성 (Electrical Characteristics of Porous Carbon Electrode According to NaCl Electrolyte Concentration)

  • 김용혁
    • 한국전기전자재료학회논문지
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    • v.23 no.10
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    • pp.814-819
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    • 2010
  • Porous carbon electrodes with wooden materials are manufactured by molding carbonized wood powder. Electrical properties of the interface for electrolyte and porous carbon electrode are investigated from viewpoint of NaCl electrolyte concentration, capacitance and complex impedance. Density of porous carbon materials is 0.47~0.61 g/$cm^3$. NaCl electrolytic absorptance of the porous carbon materials is 5~30%. As the electrolyte concentration increased, capacitance is increased and electric resistance is decrease with electric double layer effect of the interface. The electric current of the porous carbon electrode compared in the copper and the high density carbon electrode was improved on a large scale, due to a increase in surface area. The circuit current increased as the distance between of the porous carbon electrode and the zinc electrode decreased, due to increase in electric field. Experimental results indicated that the current properties of galvanic cell could be improved by using porous carbon electrode.

Comparison of Electrode Backing Materials for Polymer Electrolyte Membrane Fuel Cells

  • Sasikumar, G.;Ryu, H.
    • 전기화학회지
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    • v.6 no.3
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    • pp.183-186
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    • 2003
  • In a PEM fuel cell electrode, backing layer has tremendous impact on electrode performance. The backing layer provides structural support for the porous electrode, distributes the reactants to the other layers and acts as a current collector. It has major influence on the water management in a PEM fuel cell. Selection of suitable backing layer material for the fabrication of electrode is thus very important to achieve high performance. In this paper we have compared the performance of PEM fuel cell electrodes fabricated using carbon paper EC-TPI-060T, carbon cloth EC-CCI-060T, (ElectroChem Inc.USA) and Carbon cloth from Textron, USA (CPW 003 grade). Mass transport problem was observed under non-pressurized condition, at high current densities, in the caie of EC-CC1-060T carbon cloth electrode (at $50^{\circ}C$), due to its higher thickness. The performance of carbon paper electrode was higher than EC-CCI-060T carbon cloth electrode. The performance of Textron carbon cloth was comparable to EC-TPI -060T carbon paper.

염료감응형 태양전지의 탄소대항전극 제조시 바인더에 따른 영향 (Effects by Changing Binder Contents in The Carbon Counter Electrode for Dye-sensitized Solar Cells)

  • 김성준;권정열;이현석;박정철;이헌용
    • 한국전기전자재료학회:학술대회논문집
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    • pp.114-115
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    • 2006
  • In the present study we investigated effects by changing binder contents m the carbon counter electrode for dye-sensitized solar cells. Binder contents changed for 6 wt%, 7 wt%, 8 wt% before making carbon electrode. In the result of the measurement the specific resistance for 6 wt% was lowest among others And the surface of the carbon electrode which was measured by SEM was best m the 6 wt"%. The electrode properties be showing in an experiment were due to increment of surface roughness that appeared the carbon electrode, which decreased internal surface area.

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흑연계 및 비흑연계 탄소로 조합된 리튬이온 이차전지의 탄소부극 특성 (Performance of the Negative Carbon Electrode Prepared with Graphitic Carbon and Nongraphitic Carbon Material in Lithium Ion Secondary Battery)

  • 김현중;이철태
    • 공업화학
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    • v.9 no.7
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    • pp.1065-1069
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    • 1998
  • 리튬이온 이차전지에 사용되는 탄소부극의 성능을 향상시키기 위하여 결정성계 탄소재료와 비결정성계 탄소재료의 혼합비율에 따른 조합형 탄소전극을 제조하였으며, 이들의 전기화학적 특성과 충방전 특성을 조사하여 조합비율에 따른 리튬의 삽입과 탈삽입 반응기구 및 최적의 조합조건을 찾고자 하였다. 탄소전극은 결정성계 탄소재료인 natural graphite와 $700^{\circ}C$에서 1시간 동안 열처리된 비결정성계 탄소재료인 petroleum cokes를 사용하였다. 조합비에 따라 제조된 조합형 탄소전극은 두 가지 형태의 탄소재료가 갖는 전극특성을 지니며 50:50wt%로 조합하였을 때 가장 우수한 전기화학적 특성과 충 방전 특성을 나타냈다.

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Lithium intercalation into a plasma-enhanced-chemical-vapour-deposited carbon film electrode

  • Pyun Su-II
    • 전기화학회지
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    • v.2 no.1
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    • pp.38-45
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    • 1999
  • Electrochemical lithium intercalation into a PECVD (plasma enhanced chemical vapour deposited) carbon film electrode was investigated in 1 M $LiPF_6-EC$ (ethylene carbonate) and DEC (diethyl carbonate) solution during lithium intercalation and deintercalation, by using cyclic voltammetry supplemented with ac-impedance spectroscopy. The size of the graphitic crystallite in the a- and c-axis directions obtained from the carbon film electrode was much smaller than those of the graphite one, indicating less-developed crystalline structure with hydrogen bonded to carbon, from the results of AES (Auger electron spectroscopy), powder XRD (X-ray diffraction) method, and FTIR(Fourier transform infra-red) spectroscopy. It was shown from the cyclic voltammograms and ac-impedance spectra of carbon film electrode that a threshold overpotential was needed to overcome an activation barrier to entrance of lithium into the carbon film electrode, such as the poor crystalline structure of the carbon film electrode showing disordered carbon and the presence of residual hydrogen in its structure. The experimental results were discussed in terms of the effect of host carbon structure on the lithium intercalation capability.

염료감응 태양전지용 고성능 탄소 상대전극 제작 (Fabrication of High-performance Carbon Counter Electrode for Dye-sensitized Solar Cells)

  • 장연익;이승용;김동환;박종구
    • 한국분말야금학회지
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    • v.14 no.1
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    • pp.44-49
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    • 2007
  • In the fabrication of dye-sensitized solar cells (DSSCs), carbon counter electrode has been tested for replacing the platinum counter electrode which has two drawbacks: limited surface area and high material cost. Poor mechanical stability of carbon layer due to weak bonding strength to electrically conductive TCO (transparent conducting oxide) glass substrate is a crucial barrier for practical application of carbon counter electrode. In the present study a carbon counter electrode with high conversion efficiency, comparable to Pt counter electrode, could be fabricated by adaption of a bonding layer between particulate carbon material and TCO substrate.

The Characteristics of Sulfur Electrode with Carbon Nanotube

  • Ryu, Ho-Suk;Lee, Sang-Won;Kim, Ki-Won;Ahn, Joo-Hyun;Cho, Kwon-Koo;Cho, Gyu-Bong;Ahn, Hyo-Jun
    • 한국분말야금학회:학술대회논문집
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    • pp.1216-1217
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    • 2006
  • We investigated on the additive effect of carbon nanotube in the sulfur electrode on the first discharge curve and cycling property of lithium/sulfur cell. The sulfur electrode with carbon nanotube had two discharge plateau potentials and the first discharge capacity about 1200 mAh/g sulfur. The addition carbon nanotube into the sulfur electrode did not affect the first discharge behavior, but improved the cycling property of lithium/sulfur cell. The optimum content of carbon nanotube was 6 wt% of sulfur electrode

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Platinum and carbon nano tube addition in carbon black counter electrode for dye-sensitized solar cells

  • Lee, Su Young;Kim, Sang Ho
    • 한국표면공학회:학술대회논문집
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    • pp.229-230
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    • 2012
  • Platinum (Pt) has been commonly used as a counter electrode material in dye-sensitized solar cells, because it has high catalytic activity and electric conductivity as well as chemical inertness with iodide electrolyte. However, Pt is too expensive to be commercialized. Therefore, in the present study, carbon black counter electrode with Pt and carbon nano tube (CNT) was investigated. The power conversion efficiency with Pt added carbon black electrode was lower than hat of pure Pt electrode which was 6.47 %. By adding 3 wt% Pt to the carbon black counter electrode, the power conversion efficiency was maximized at 5.88 %. On them, additional adding of 1 wt % CNT, the power conversion efficiency (${\eta}$)wasincreasedupto6.21%. The reason of power conversion efficiency improvement with a proper amount of Pt and CNT was examined by comparing the impedance properties measured using EIS.

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Influence of Carbon Black as a Conductor on Electrode Characteristics for Lithium Secondary Battery

  • Yoon, Se-Rah;Lee, Joong-Kee;Ju, Jae-Beck;Cho, Byung-Won;Park, Dal-Keun
    • Carbon letters
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    • v.3 no.1
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    • pp.17-24
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    • 2002
  • The electrochemical behavior of the $LiCoO_2$ electrode, containing carbon black as a conductor, depends upon the nature and characteristics of carbon black. In this study, six different kinds of carbon blacks were employed to investigate the relationship between the properties of carbon blacks and electrochemical characteristics of the electrode. The larger amount of surface oxygen functional groups brought the lower electrical conductivity for the carbon blacks. The electrical conductivity of carbon blacks was closely related to the impurities such as ash and volatile content. The rate capability and cyclability of the electrode were improved with the higher conductivity of carbon blacks used. So, it can be concluded that high conductive carbon black plays an important role as a conductor for high rate of charge-discharge capability and initial efficiency.

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Carbon-free Polymer Air Electrode based on Highly Conductive PEDOT Micro-Particles for Li-O2 Batteries

  • Yoon, Seon Hye;Kim, Jin Young;Park, Yong Joon
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.220-228
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    • 2018
  • This study introduced a carbon-free electrode for $Li-O_2$ cells with the aim of suppressing the side reactions activated by carbon material. Micro-particles of poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting polymer, were used as the base material for the air electrode of $Li-O_2$cells. The PEDOT micro-particles were treated with $H_2SO_4$ to improve their electronic conductivity, and LiBr and CsBr were used as the redox mediators to facilitate the dissociation of there action products in the electrode and reduce the over-potential of the $Li-O_2$ cells. The capacity of the electrode employing PEDOT micro-particles was significantly enhanced via $H_2SO_4$ treatment, which is attributed to the increased electronic conductivity. The considerable capacity enhancement and relatively low over-potential of the electrode employing $H_2SO_4$-treated PEDOT micro-particles indicate that the treated PEDOT micro-particles can act as reaction sites and provide storage space for the reaction products. The cyclic performance of the electrode employing $H_2SO_4$-treated PEDOT micro-particles was superior to that of a carbon electrode. The results of the Fourier-transform infrared spectroscopic analysis showed that the accumulation of residual reaction products during cycling was significantly reduced by introducing the carbon-free electrode based on $H_2SO_4$-treated PEDOT micro-particles, compared with that of the carbon electrode. The cycle life was improved owing to the effect of the redox mediators. The refore, the use of the carbon -free electrode combined with redox mediators could realize excellent cyclic performance and low over-potential simultaneously.