• 한국태양에너지학회 논문집
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• 제34권4호
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• pp.9-16
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• 2014

A proton exchange membrane is a core component in the proton exchange membrane fuel cell because the role of proton exchange membrane(PEM)is supplying proton conductivity to fuel cell, a gas separator, and insulating between an anode and cathode. Among various role of PEM, supplying proton conductivity is the most important and the proton conductivity is strongly related the structural evolution of PEM by hydration. Thus a lot of studies have done by past few decade based on small angle X-ray scattering and wide angle X-ray scattering for understanding morphological structure of the PEM. Resulting from these studies, several morphological models of hydrated PEM are proposed. Current sensing atomic force microscopy (CSAFM) can map morphology and conductance on the membrane simultaneously. It can be the best tool for studying heterogenous structured materials such as PEM. In this study, the hydration of the membrane is examined by using CSAFM. Conductance and morphological images are simultaneously mapped under different relative humidity. The conductance images, which are mapped from different relative humidity, are analyzed by statistical methode for understanding ionic channel variation in PEM.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.38-50
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• 2023

Proton exchange membrane fuel cell (PEMFC) is a portable and clean power generation device. The structural arrangement of the flow field has a significant influence on the delivery efficiency of PEMFC. In this article, a new bionic flow channel is designed based on the inspiration of a spider shape. The branch channel width and branch corner are studied as the focus, and its simulation is carried out by the method of computational fluid dynamics (CFD). The results show that when channel width/rib width and corner of the branch are 1.5 and 130° , respectively, it is the best numerical combination and the cell comprehensive performance is excellent. The final model using this numerical combination is compared with the traditional flow channel model to verify the advancement of this scheme.

• 공업화학
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• 제29권5호
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• pp.489-496
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• 2018

화학에너지를 전기에너지로 전환하는 친환경 에너지 자원으로 각광받는 연료전지에서 고분자 전해질 연료전지(proton exchange membrane fuel cell, PEMFC)의 비싼 백금촉매 사용, 고온가습조건에서의 전도도 감소 등의 문제로 음이온교환연료전지(anion exchange membrane fuel cell, AEMFC)가 주목을 받고 있다. 음이온교환연료전지는 비백금계 촉매를 사용하고 산소환원반응의 활성화 에너지가 낮아 효율이 더 우수한 장점이 있다. 하지만, 이산화탄소에 노출되어 전극손상, 이온전도도 감소 등의 문제점을 포함하여 여러 가지 해결해야 할 문제점이 있다. 따라서, 본 미니총설은 음이온 교환연료전지의 다양한 문제점을 여러 연구논문을 통해서 해결방안을 제시하고자 한다.

• 멤브레인
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• 제22권3호
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• pp.155-170
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• 2012

연료전지는 석유엔진과 비교하여 높은 전류밀도와 효율성, 그리고 친환경적이기 때문에 21세기 들어 대체 발전시스템으로서 각광받아왔다. 연료전지 시스템에서 고분자 전해질 막은 핵심부품으로써 현재 Nafion막이 연료전지시스템에서 사용 중이지만 높은 제조단가와 고온에서 낮은 전도도를 가지는 단점을 가지고 있다. 그러므로 많은 학자들이 낮은 제조단가, 높은 물리적 특성들을 달성하기 위한 연구를 진행하여 왔으며 연료전지의 상용화와 동시에 고성능의 연료전지의 개발을 위하여 많은 방법들이 개발되어 왔다. 그중, 유무기 복합막은 유기물과 무기물의 물성을 균일하게 조합할 수 있으므로 잠재성을 가지고 있는 제조방법이다. 본고에서는 다양한 무기물이 사용되어 제조된 유무기 복합막의 연구동향에 대하여 조사하였다.

• 한국수소및신에너지학회논문집
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• 제23권3호
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• pp.250-255
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• 2012

In this paper, the development and performance analysis of a fuel cell-powered unmanned aerial vehicle is described. A fuel cell system featuring 1 kW proton exchange membrane fuel cell combined with a highly pressurized fuel supply system is proposed. For the higher fuel consumption efficiency and simplification of overall system, dead-end type operation is chosen and each individual system such as purge system, fuel supply system, cooling system is developed. Considering that fluctuation of exterior load makes it hard to stabilize fuel cell performance, the power management system is designed using a fuel cell and lithium-ion battery hybrid system. After integration of individual system, the performance of unmanned aerial vehicle is analyzed using data from flight and laboratory test. In the result, overall system was properly operated but for more duration of flight, research on weight lighting and improvement of fuel efficiency is needed to be progressed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.374-377
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• 2009

The operating temperature of Proton Exchange Membrane Fuel Cell (PEMFC) usually has to be limited under $100^{\circ}C$ to maintain the proper ionic conductivity. Therefore, the only product from reaction, water, is in the liquid phase. Two-phase flow makes the flow phenomenon in the channel difficult to understand and predict. Water blocking in the PEMFC channel or the pore of Gas Diffusion Layer (GDL), called flooding, is known as the main effect of PEMFC degradation. To analyze two-phase flow, the PEMFC with transparent acrylic plate was used. Two-phase flow patterns were observed by varying the current density. When the PEMFC is mounted horizontally, water in the cathode is mainly transported on the interface between the channel and GDL.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.6-9
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• 2008

The efficiency and life time of the proton exchange membrane (PEM) fuel cell system is critically changed with its humidity which should be maintained properly during dynamic operation. Membrane humidifier is required to regulate proper humidity level for the design point of the PEMFC system. In this study, we presented the performance of the cylindrical membrane humidifier which is operated as water-to-gas. Dry air pressure, liquid water flow temperature, and air flow rate were chosen as the operating parameters. Humidity level is expressed with dew point.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.76.2-76.2
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• 2010

The gas diffusion layer is the key component of the proton exchange membrane fuel cell because it directly affect to the mass transport mechanism and dynamic behavior of the cell. In this study, the effects of GDL aging on the transient response of the PEM fuel cell is systematically investigated using current step transient response analysis under different stoichiometric ratios and humidity conditions. With GDLs aged by the accelerated stress test, the effects of hydrophobicity and structural changes due to carbon loss in the GDL on the transient response of PEM fuel cells are determined. The degraded GDLs that had uneven hydrophobicity distributions cause local water flooding inside the GDL and induce lower and unstable voltage responses after load changes.

• 전기화학회지
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• 제12권3호
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• pp.219-233
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• 2009

Mobile devices in the next generation such as camera, cell phone, network, Note PC, etc. require higher power and energy sources due to convergences of various functions. Direct methanol fuel cell (DMFC) has been focused as an attractive power source, but there are critical issues involved in its commercialization with regard to the core technologies of materials, components, and system. The requirements of key technologies are differentiated from applications and fuel supply methods. Here, the roles of the proton-conducting membrane are discussed and the current status of DMFC systems is discussed in terms of proton conductivity, methanol permeability, and water management. Materials such as perfluorinated and partially fluorinated membranes, hydrocarbon membranes, composite membranes, and other modified ionomers have been studied. These would explain the critical issues of DMFC and the role of membranes for commercialization.

• 한국전기전자재료학회논문지
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• 제23권7호
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• pp.530-533
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• 2010

The proton exchange membrane fuel cell (PEMFC) holds great promise of clean power. However, in practical applications which use the PEMFC as the power source, the output voltage from the fuel cell undergoes a transient response especially during acceleration and deceleration. This paper presents the relationships between the charge curves of the internal voltage rise, discharge curves of the internal voltage drop, the voltage with a time constant $V_{\tau}$ and finally, the load and time constant $\tau$ of $FC_1$ and $FC_2$, connected both in series and in parallel.