• 제목/요약/키워드: Polymer electrolyte membrane Fuel cell

검색결과 467건 처리시간 0.023초

Corrosion characteristics and interfacial contact resistances of TiN and CrN coatings deposited by PVD on 316L stainless steel for polymer electrolyte membrane fuel cell bipolar plates

  • Lee, Jae-Bong;Oh, In Hwan
    • Corrosion Science and Technology
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    • 제12권4호
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    • pp.171-178
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    • 2013
  • In a polymer membrane fuel cell stack, the bipolar plate is a key element because it accounts for over 50% of total costs of the stack. In order to lower the cost of bipolar plates, 316L stainless steels coated with nitrides such as TiN and CrN by physical vapor deposition were investigated as alternative materials for the replacement of traditional brittle graphite bipolar-plates. For this purpose, interfacial contact resistances were measured and electrochemical corrosion tests were conducted. The results showed that although both TiN and CrN coatings decreased the interfacial contact resistances to less than $10m{\Omega}{\cdot}cm^2$, they did not significantly improve the corrosion resistance in simulated polymer electrolyte membrane fuel cell environments. A CrN coating on 316L stainless steel showed better corrosion resistance than a TiN coating did, indicating the possibility of using modified CrN coated metallic bipolar plates to replace graphite bipolar plates.

고분자 전해질막 연료전지의 활성화를 위한 CV 활성화법 (Application of CV Cycling to the Activation of the Polymer Electrolyte Membrane Fuel Cell)

  • 조기윤;정호영
    • 공업화학
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    • 제23권5호
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    • pp.445-449
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    • 2012
  • 고분자 전해질막 연료전지의 대량 생산을 위하여 막-전극 접합체(MEA) 활성화 방법의 개발이 중요한 현안이다. 현재 개발된 MEA활성화 방법은 시간이 많이 소요됨으로 인해 수소의 사용량 또한 증가하여 연료전지의 상용화에 큰 걸림돌이 되고 있다. 통상적인 활성화 방법은 활성화 원리를 주로 전해질 수화 관점에서 이해하였다. 반면, 본 논문에서 제안된 순환전압전류(cyclic voltammetry, CV) 활성화 방법은 전해질 및 촉매적 관점에서 별도로 분리하여 이해하였다. 따라서 전해질 관점에서는 상대 습도 100%인 가습된 질소를 공급하여 전극 및 막의 전해질을 수화시키는 과정으로 구성되고, 촉매적 관점에서는 CV 사이클을 수행하여 백금 촉매에 흡착되어 있는 불필요한 오염물질, 또는 산화피막을 제거하는 과정으로 수행된다. CV 활성화법은 2.5 h 내에 활성화가 종료되어 활성화 시간을 크게 단축시킬 수 있을 뿐만 아니라, 수소 사용량도 기존 활성화 방법에 비하여 1/4 이하로 감소시킬 수 있어서 효과적인 연료전지 활성화 방법으로 제안하고자 한다.

전력공급장치를 이용한 선박용 연료전지 시뮬레이터의 구현 (Implementation of Fuel Cell Simulator for Ship Using the Programmable Power Supply)

  • 박도영;오진석
    • Journal of Advanced Marine Engineering and Technology
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    • 제36권8호
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    • pp.1117-1122
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    • 2012
  • 연료전지를 선박에 적용하는 연구를 위해서는 연료전지 특성을 고려한 전력 시스템 설계 및 부하 제어에 대한 연구가 필요하다. 하지만 연료전지를 직접 실험하기 위해서는 여러 보조기기들과 복잡한 제어 기술이 필요하다. 이러한 이유로 연료전지 시뮬레이터가 필요하며, 이를 위한 연구가 활발히 진행중이다. 본 논문에서는 자동차, 소형 선박 등에 적용되고 있는 PEMFC에 관하여 LabVIEW를 기반으로 시뮬레이션 하였다. 또한 이러한 시뮬레이션 데이터를 바탕으로 프로그램이 가능한 전력공급장치를 이용하여 시뮬레이터를 제작하여 연료전지의 특성을 구현하였다. 이를 통해 연료전지의 분극화 곡선과 변수에 따른 I-V특성을 확인할 수 있었다.

The Analysis on the Activation Procedure of Polymer Electrolyte Fuel Cells

  • Jang, Jong-Mun;Park, Gu-Gon;Sohn, Young-Jun;Yim, Sung-Dae;Kim, Chang-Soo;Yang, Tae-Hyun
    • Journal of Electrochemical Science and Technology
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    • 제2권3호
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    • pp.131-135
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    • 2011
  • It is, in general, believed that during the activation process, the proton conductivity increases due to wetting effect and the electrochemical resistance reduction, resulting in an increase in the fuel cell performance with time. However, until now, very scant information is available on the understanding of activation processes. In this study, dominant variables that effect on the performance increase of membrane electrode assemblies (MEAs) during the activation process were investigated. Wetting, pore restructuring and active metal utilization were analyzed systematically. Unexpectedly, the changes for both ohmic and reaction resistance characterized by the electrochemical impedance spectroscopy (EIS) after initial wetting process were much smaller when considering the degree of cell performance increases. However, the EIS spectra represents that the pore opening of electrode turns into gas transportable structure more easily. The increase in the performance with activation cycles was also investigated in a view of active metals. Though the particle size was grown, the number of effective active sites might be exposed more. The impurity removal and catalytic activity enhancement measured by cyclic voltammetry (CV) could be a strong evident. The results and analysis revealed that, not merely wetting of membrane but also restructuring of electrodeand catalytic activity increase are important factors for the fast and efficient activation of the polymer electrolyte fuel cells.

고분자 전해질 연료전지에서 탄소복합 기체확산층의 제조와 특성분석 (Preparation and Characterization for Carbon Composite Gas Diffusion Layer on Polymer Electrolyte Membrane Fuel Cells)

  • 심중표;한춘수;선호정;박경세;이지정;이홍기
    • 한국수소및신에너지학회논문집
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    • 제23권1호
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    • pp.34-42
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    • 2012
  • Gas diffusion layers (GDLs) of carbon composite type in polymer electrolyte fuel cells were prepared by simple and cheap manufacturing process. To obtain the carbon composite GDLs, carbon black with polymer binder was mixed in solvent, rolled to make sheet, and finally heat-treated at $340^{\circ}C$. The performance of fuel cell using composite GDLs was changed by PTFE content. The physical properties of composite GDLs for pore, conductivity and air permeability were analyzed to compare with the variation of fuel cell performance. The conductivity of composite GDLs was very similar to carbon paper as commercial GDL but pore properties and air flux were considerably different. The porosity, PTFE content and conductivity for composite GDLs did not have an influence on the cell performance much. The increase of pore diameter and air flux led to enhance cell performance.

Sulfonated Dextran/Poly(vinyl alcohol) Polymer Electrolyte Membranes for Direct Methanol Fuel Cells

  • Won, Jong-Ok;Ahn, Su-Mi;Cho, Hyun-Dong;Ryu, Ji-Young;Ha, Heung-Yong;Kang, Yong-Soo
    • Macromolecular Research
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    • 제15권5호
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    • pp.459-464
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    • 2007
  • Polymer electrolyte membranes, featuring ionic channels, were prepared from sulfonated dextran/ poly(vinyl alcohol) (sD/PVA) membranes. A stiff sulfated dextran was chosen as the route for ionic transport, since ionic sites are located along the stiff dextran main chain. The sD/PVA blend membranes were annealed and then chemically crosslinked. The characteristics of the crosslinked sD/PVA membranes were investigated to determine their suitability as proton exchange membranes. The proton conductivity was found to increase with increasing amounts of sD inside the membrane, which reached a maximum and then decreased when the sD content exceeded 30 wt%, while the methanol permeability increased with increasing sD content. The good dispersion of sD inside the membrane, which serves as an ionic channels mimic, played a significant role in proton transportation.

5kW급 고분자 연료전지 시스템의 개발과 운전 (Development and Operation of 5kW-Class Polymer Electrolyte Membrane Fuel Cell System)

  • 전영갑;백동현;전광선;김창수;신동렬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1876-1878
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    • 1999
  • Developed was a 5kW-class polymer electrolyte membrane fuel cell(PEMFC) system comprised of fuel cell stack, fuel processing, thermal and water management subsystems and ancillary equipments. Several large single cells have been fabricated with different gas flow field patterns and paths, and the gas flow field pattern for the stack has been determined based on the single cell performance of thin film membrane electrode assembly (MEA). The PEMFC stack was consisted of 100 cells with an electrode area of $300cm^2$, having serpentine flow pattern. Fuel processing was developed including an autothermal methanol reformer and two preferential CO oxidation reactors. The fuel processing was combined to PEMFC operation system consisted of air compressor and thermal and water management subsystems. The PEMFC stack showed performance of 5kW under the supply of $H_2$ and air, but its performance was lowered to 3.5kW under the supply of reformed gas.

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PEMFC Operation Connected with Methanol Reformer System

  • Lee, Jung-Hyun;Park, Sang-Sun;Shul, Yong-Gun;Park, Jong-Man;Kim, Dong-Hyun;Kim, Ha-Suck;Yoo, Seung-Eul
    • Carbon letters
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    • 제9권4호
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    • pp.303-307
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    • 2008
  • The studies on integrated operation of fuel cell with fuel processor are very essential prior to its commercialization. In this study, Polymer Electrolyte Membrane Fuel Cell (PEMFC) was operated with a fuel processor, which is mainly composed of two parts, methanol steam reforming reaction and preferential oxidation (PROX). In fuel processor, ICI 33-5 (CuO 50%, ZnO 33%, $Al_2O_3$ 8%, BET surface area: $66\;m^2g^{-1}$) catalyst and CuO-$CeO_2$ catalyst were used for methanol steam reforming, preferential oxidation (PROX) respectively. PEMFC was operated by hydrogen fuel generated from fuel processor. The resulting gas from PROX reactor is used to operate PEMFC equipped with our prepared anode and cathode catalyst. PtRu/C catalyst gives more tolerance to CO.

Pt 나노 입자가 도입된 연료전지용 탄화수소계 고분자 전해질 복합막의 제조 및 특성 (Fabrication of Hydrocarbon Polymer Electrolyte Composite Membrane Incorporated with Pt Nanopartle for PEMFC and Its Characteristics)

  • 이홍기
    • 한국수소및신에너지학회논문집
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    • 제28권3호
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    • pp.246-251
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    • 2017
  • To fabricate a hydrocarbon polymer electrolyte composite membrane incorporated with Pt nanoparticle, the polymer electrolyte membrane made of a sulfonated-fluorinated hydrophilic-hydrophobic block copolymer (SFBC) and sulfonated poly (ether ether ketone) (SPEEK) blend in the wight ratio of 1 : 1 was synthesized, and a simple drying process was used in order to incorporate Pt nanoparticle into the SFBC/SPEEK film by reducing platinum (II) bis (acetylacetonate), Pt $(acac)_2$. The distribution of the Pt nanoparticles was observed by transmission electron microscopy (TEM), and mechanical and thermal properties were tested by universal testing machine (UTM) and thermogravimetry analyzer (TGA). Cation conductivity, ion exchange capacity (IEC) and I-V characteristics were estimated.