• 한국응용과학기술학회지
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• 제22권2호
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• pp.151-156
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• 2005

Many researchers have been focused on polymer electrolyte membrane (PEM) to improve performance of a fuel cell. Sulfonpolyimide with hydrocarbon was synthesized from ODA (4,4-diaminodiphenyl ether), ODADS (4,4-diaminodiphenyl ether-2,2-disulfonic acid), NTDA (1,4,5,8-naphthalenetetracarboxylicdianhydride) and CSA (chlorosulfonic acid). In order to estimate the feasibility as a fuel cell, the performance of sulfonpolyimide was analyzed through a swelling degree, IEC (ion exchange capacity), ion conductivity and TEM (transmission electron microscope). As the results of this performance test, swelling degree, IEC and ion conductivity were 37%, 0.06 meq/g and 0.08 S/cm respectively, when the CSA concentration was 0.4 M. It was thought that sulfonpolyimide could be used as a fuel cell through improvement of electrolyte membrane.

• 마이크로전자및패키징학회지
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• 제11권1호
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• pp.65-69
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• 2004

스크린 프린팅법은 고분자 전해질 연료전지의 전극 촉매층 제조의 편리함과 적용성의 면에서 가장 일반적인 방법 중에 하나이다. 본 논문은 기존의 방법과 비교하여 매우 낮은 백금 함침량을 가지기 때문에 경쟁적이고, 부가적인 공정 없이 swelling 문제를 간단하게 억제시켜 개선된 스크린 프린팅 법을 제안하였다. 특히, 가스켓 일체형 MEA는 고분자 전해질 연료전지의 작동 중에 가스 침투의 영향을 방지하여 고전류 영역에서 기존의 방법으로 제조된 MEA보다 높은 성능을 가지게 제작하였다. 이와 같은 방법들은 보다 간단하고 빠른 제조의 기회를 준다.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.559-567
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• 2011

This paper deals with an economic evaluation of domestic low-temperature water electrolysis hydrogen production. We evaluate the economic feasibility of on-site hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ by the alkaline and the polymer electrolyte membrane water electrolysis. The hydrogen production prices of the alkaline water electrolysis, the polymer electrolyte membrane water electrolysis, and the steam methane reforming hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ were estimated as 18,403 $won/kgH_2$, 22,945 $won/kgH_2$, 21,412 $won/kgH_2$, respectively. Domestic alkaline water electrolysis hydrogen production is evaluated as economical for small on-site hydrogen fueling stations, and we need to further study the economic evaluation of low-temperature water electrolysis hydrogen production for medium and large scale on-site hydrogen fueling stations.

• 한국전기전자재료학회논문지
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• 제25권1호
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• pp.33-36
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• 2012

In this study, the thickness effects of $Al_2O_3$ layer on the sensing properties of $SiO_2/Al_2O_3$ (OA) stacked membrane were investigated using electrolyte-insulator-semiconductor (EIS) structure for high quality pH sensor. The $Al_2O_3$ layers with a respective thickness of 5 nm, 15 nm, 23 nm, 50 nm, and 100 nm were deposited on the 5-nm-thick $SiO_2$ layers. The electrical characteristics and sensing properties of each OA membranes were investigated using metal-insulator-semiconductor (MIS) and EIS devices, respectively. As a result, the OA stacked membrane with 23-nm-thick $Al_2O_3$ layer shows the excellent characteristics as a sensing membrane of EIS sensor, which can enhance the signal to noise ratio.

• 멤브레인
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• 제20권3호
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• pp.173-184
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• 2010

미생물 연료전지는 신재생에너지로서 미생물이 유기물을 분해하는 신진대사 과정을 통해서 전기에너지를 생성한다. 각종 유기물이 풍부한 폐수를 이용하여 전력을 생산할 뿐 아니라, 슬러지 발생량도 감축할 수 있는 미래 전도유망한 친환경에너지이다. 하지만 이를 상용화하기 위해서는 전지 내부에서 발생하는 모든 저항요소들을 감소시켜 더 높은 전력밀도를 생산해야 될 필요가 있다. 예를 들어 신진대사가 활발한 미생물의 종류, 미생물과 전극의 효과적인 전자전달 과정, 전극의 재료 및 형태 등의 개선을 통하여 전력밀도를 높일 수 있다. 특히, 고분자 전해질 분리막의 성능개선은 산화, 환원전극조를 완벽히 분리할 뿐만 아니라, 환원전극으로의 수소이온 전도도를 높여 내부저항을 줄일 수 있는 핵심 요소이다.

• 공업화학
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• 제10권2호
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• pp.177-182
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• 1999

대기중의 이산화탄소가 공기-아연전지에 미치는 영향을 검토하기 위하여 수산화칼륨 수용성 전해액을 공기와 접촉시킨 다음 시간의 경과에 따라 전해액중의 탄산칼륨 농도를 분석하여 전지 용량과의 관계를 규명하고자 하였다. 전해액은 공기와 접촉하는 시간이 경과함에 따라 대기중의 이산화탄소 흡수로 인하여 탄산칼륨의 농도가 증가하였으나 이에 비례하여 전지의 용량은 선형적으로 감소하였다. 이산화탄소의 흡수반응속도는 소수성 막의 세공크기가 주 인자로 작용하였으며, 세공크기를 조절한 소수성 막을 사용한 결과 이산화탄소 흡수로 인한 전지용량 열화현상을 현저히 감소시킬 수 있었다.

• Journal of Electrochemical Science and Technology
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• 제7권4호
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• pp.269-276
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• 2016

Carbon-supported ordered Pt-Ti alloy nanoparticles were prepared as a durable and efficient oxygen reduction reaction (ORR) electrocatalyst for polymer electrolyte membrane fuel cells (PEMFCs) via wet chemical reduction of Pt and Ti precursors with heat treatment at $800^{\circ}C$. X-ray diffraction analysis confirmed that the prepared electrocatalysts with Ti precursor molar compositions of 40% (PtTi40) and 25% (PtTi25) had ordered $Pt_3Ti$ and $Pt_8Ti$ structures, respectively. Comparison of the ORR polarization before and after 1500 electrochemical cycles between 0.6 and 1.1 V showed little change in the ORR polarization curve of the electrocatalysts, demonstrating the high stability of the PtTi40 and PtTi25 alloys. Under the same conditions, commercial carbon-supported Pt nanoparticle electrocatalysts exhibited a negative potential shift (10 mV) in the ORR polarization curve after electrochemical cycling, indicating degradation of the ORR activity.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.364-374
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• 2010

Design of a reformer consisting of combustion chamber and reforming chamber was investigated for a 1 kW and a 5 kW polymer electrolyte membrane fuel cell (PEMFC), respectively, using the computational fluid dynamics (CFD). First, the 1kW reformer was considered to obtain the reliability of the numerical study. It was modeled, calculated and compared with experimental data. Second, the 5kW reformer was considered for a geometric study. Three tip sizes (35, 40, and 45 mm) and five aspect ratios was selected. It was found that the optimum was at tip sizes of 40 and 45 mm, at aspect ratios of -10% and -20% of the standard length.

• 한국수소및신에너지학회논문집
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• 제25권4호
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• pp.386-392
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• 2014

The effective water management in a polymer electrolyte membrane fuel cell (PEMFC) is one of the key strategies for improving cell performance and durability. In this work, an ex situ measurement was carried out to understand the water droplet behavior on the surface of gas diffusion layer (GDL) as a fundamental study for establishing novel water management. For that purpose, simplified cell including one rib and two flow channels was designed and fabricated. Using this ex situ device, the water droplet emergence through the GDL of the PEMFC was emulated to understand liquid water transport through the porous diffusion medium. Through the visualization experiment, the emergence and growth of water droplets at the channel/GDL interface are mainly observed with the surface characteristics of GDL (SGL 10BA, 24BA) and rib when the liquid water passes through the GDL and is expelled to the flow channel. It is expected that the results obtained from this study can contribute to the better understanding on the water droplet behavior (emergence and removal) in the flow channels of PEMFC.

• 세라미스트
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• 제21권4호
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• pp.331-348
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• 2018

With the expectation to overcome the problem of increasing energy consumption, polymer electrolyte membrane fuel cells are getting more attention as a promising environmentally friendly and sustainable next-generation energy conversion system. In spite of the rapid improvement of polymer electrolyte membrane fuel cells(PEMFCs), there are several critical issues still need to be resolved for practical commercialization. Out of the many issues, the main hurdle comes from oxygen reduction reaction(ORR), thus development of efficient ORR electrocatalysts is the main key for enhancing PEMFC performance. Among various catalysts, 1D nanostructured catalyst is a promising candidate because it holds many advantages that come from nanostructuring while supplementing the disadvantages of other nanostructures such as nanoparticles(0D) or gyroids(3D). This review focused on diverse 1D nanostructures and talks about their advantages as catalyst for ORR. Different 1D nanostructures will be introduced while applying the structures to different materials system showing the prospects of 1D nanostructures for improving PEMFC.