• 한국군사과학기술학회지
• /
• 제20권4호
• /
• pp.491-496
• /
• 2017

The hydrogen($H_2$) is promising energy carrier of renewable energy in the microgrid system such as small village and military base due to its high energy density, pure emission and convenient transportation. $H_2$ can be generated by photocatalytic water splitting, gasification of biomass and water electrolysis driven by solar cell or wind turbine. Solid oxide electrolysis cells(SOECs) are the most efficient way to mass production due to high operating temperature improving the electrode kinetics and reducing the electrolyte resistance. The SOECs are consist of nickel-yttria stabilized zirconia(NiO-YSZ) fuel electrode / YSZ electrolyte / lanthanum strontium manganite-YSZ(LSM-YSZ) air electrode due to similarity to Solid Oxide Fuel Cells(SOFCs). The Ni-YSZ most widely used fuel electrode shows several problems at SOEC mode such as degradation of the fuel electrode because of Ni particle's redox reaction and agglomeration. Therefore Ni-YSZ need to be replaced to an alternative fuel electrode material. In this study, We studied on the Double perovskite $PrBrMnO_{5+{\delta}}$(PBMO) due to its high electric conductivity, catalytic activity and electrochemical stability. PBMO was impregnated into the scaffold electrolyte $La_{0.8}Sr_{0.2}Ga_{0.85}Mg_{0.15}O_{3-{\delta}}$(LSGM) to be synthesized at low temperature for avoiding secondary phase generated when it exposed to high temperature. The Half cell test was conducted at SOECs and SOFCs modes.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.169-171
• /
• 2007

A breaking layer was introduced to conventional decal transfer method in membrane electrolyte assembly fabrication for high catalyst transfer ratio. In this study, the modified decal transfer method with high catalyst transfer ratio was introduced and its performance is studied. The structural features of electrodes made by decal method were investigated using scanning electron microscopy and current-voltage polarization measurement.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2008년도 하계종합학술대회
• /
• pp.505-506
• /
• 2008

The direct methanol fuel cell (DMFC) is a promising power source for portable applications due to many advantages such as simple construction, compact design, high energy density, and relatively high energy-conversion efficiency. In this work, an electrochemical methanol sensor for monitoring the methanol concentration in direct methanol fuel cells was fabricated using a thin composite nafion membrane as the electrolyte. We have analyzed the I-V characteristic of the fabricated methanol sensor as a function of methanol concentration, catalyst electrode and platinum(Pt) dot.

• 전기화학회지
• /
• 제25권4호
• /
• pp.174-183
• /
• 2022

높은 에너지 밀도와 고순도 수소 생산의 측면에서 고분자 전해질 연료전지와 수전해가 주목받고 있다. 고분자 전해질 연료전지 및 수전해를 위한 촉매층은 귀금속 계열의 전기 촉매와 이오노머 바인더로 구성되어 있는 다공성 전극이다. 이 중 이오노머 바인더는 촉매층 내 이온 전도를 위한 3차원 네트워크 형성과 전극 반응에 필요한 또는 생성되는 물질들의 이동을 위한 기공 형성에 중요한 역할을 수행한다. 상용 과불소계 이오노머의 활용 측면에서 이오노머의 함량, 이오노머의 물성, 그리고 이를 분산시킬 분산 매체에 촉매층의 성능 및 내구성이 크게 달라진다. 현재까지 고분자 전해질 연료전지용 촉매층을 위한 이오노머의 활용 방법은 많은 연구가 진행되어왔으나 고분자 전해질 수전해 적용 방면에서는 촉매층 연구가 다소 미비한 실정이다. 본 총설에서는 현재까지 보고된 연료전지 측면에서의 이오노머 바인더 활용 연구결과를 요약하였으며, 수소 경제 시대의 가속화를 위해서 고분자 전해질 수전해 핵심요소 중 하나인 촉매층용 이오노머 바인더에 관한 연구에 유용한 정보를 제공하고자 한다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.86.2-86.2
• /
• 2010

In order to improve polymer electrolyte membrane fuel cell (PEMFC) durability, the durability of membrane electrode assemblies (MEA), in which the electrochemical reactions actually occur, is one of the vital issues. Many articles have dealt with catalyst layer degradation of the durability-related factors on MEAs in relation to loss of catalyst surface area caused by agglomeration, dissolution, migration, formation of metal complexes and oxides, and/or instability of the carbon support. Degradation of catalyst layer during long-term operation includes cracking or delamination of the layer which result either from change in the catalyst microstructure or loss of electronic or ionic contact with the active surface, can result in apparent activity loss in the catalyst layer. Membrane degradation of the durability-related factors on MEAs can be caused by mechanical or thermal stress resulting in formation of pinholes and tears and/or by chemical attack of hydrogen peroxide radicals formed during the electrochemical reactions. All of these effects, the mechanical damage of membrane and degradation of catalyst layers are more facilitated by uneven stress or improper MEA fabrication process. In order to improve the PEMFC durability, therefore, it is most important to minimize the uneven stress or improper MEA fabrication process in the course of the fabrication of MEA. We analyzed the effects of the MEA fabrication condition on the PEMFC durability with MEA produced using CCM (catalyst coated membrane) method. This paper also investigated the effects of MEA fabrication condition on the PEMFC durability by adding additional treatment process, hot pressing and pressing, on the MEA produced using CCM method.

• Korean Chemical Engineering Research
• /
• 제57권4호
• /
• pp.512-518
• /
• 2019

고분자연료전지용 막전극접합체(Membrane Electrode Assembly, MEA)의 저가화 및 고성능화를 위하여 촉매층을 구성하는 촉매와 이오노머의 계면 특성에 대한 이해가 중요한 연구주제가 되고 있다. 본 연구에서는 이오노머의 구조 제어를 위하여 상용 이오노머의 용매로 사용되는 물 대신에 프로필렌글리콜(Propylene Glycol, PG)을 용매로 사용하여 단측쇄(Short Side Chain, SSC) 나피온 이오노머가 분산된 현탁액을 제조하고 이를 이용하여 공기극 촉매층을 제조하여 연료전지 성능 특성을 평가하였다. PG 기반 이오노머의 함량을 20~35 wt%로 증가시키면서 제조된 촉매층의 연료전지 성능은 상용 물 기반 이오노머와는 달리 이오노머 함량이 35 wt%까지 증가함에 따라 성능도 지속적으로 증가하였다. PG 기반 이오노머의 작은 입도와 느린 건조 속도는 균일 구조의 촉매층 형성을 유도하여 수소이온전달에는 효과적이었지만 PG 기반 이오노머 필름의 낮은 산소투과도는 MEA 성능을 저하시키는 주요 문제로서 개선이 필요하였다.

• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 2002년도 연료전지심포지움 2002논문집
• /
• pp.129-134
• /
• 2002

The present paper highlights on the need to understand the correlation of the characteristics of the catalyst layer with the performance of the polymer electrolyte membrane fuel cell. The paper deals with the correlation of the platinum loading in the catalyst layer and the performance of the Polymer Electrolyte Membrane Fuel Cell(PEMFC) and also the correlation of the required hydrophiliticityihydrophobicity in the catalyst layer to get the optimum performance under given operating conditions.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 춘계학술대회
• /
• pp.110-112
• /
• 2006

Membrane electrode assembly (MEA) for polymer electrolyte fuel cell (PEFC) are commonly prepared in the research laboratory by spraying, screen-printing and brushing catalyst slurry onto membrane or other support material like carbon paper or polyimide film in a batch style. These hand applications of the catalyst slurry are painstaking process with respect to precision of catalyst loading and reproducibility. It has been generally mentioned that the adoption of continuous process is very helpful to develop the reliable product. In the present work, we report the results of using continuous type coater with doctor-blade to coat catalyst slurry for preparing the MEA catalyst layers In a faster and highly reproducible fashion. We show that while expectedly faster than batch style, the machine coater requires the use of slurry of appropriate composition and a properly selected transfer decal material in order to achieve superior MEA plat lnw loading reproducibility. To make highly viscous catalyst slurry that is imperative for using coater, we use 40wt.% Nafion solution and minimize the content of organic solvent. And the choice of proper high surface area catalyst is important in the viewpoint of making well-dispersed slurry. After catalyst coating onto the support material, we transferred the catalyst layer to both sides of Nafion membrane by hot-pressing In this case, the degree of transfer was Influenced by hot-pressing condition including temperature, pressure, and time. To compare the transferring ability, we compared so many films and detaching papers. And among the support, polyethylene terephthalate(PET) film shows the prominent result.

• 청정기술
• /
• 제19권1호
• /
• pp.59-64
• /
• 2013

고분자전해질 연료전지에서 사용되는 전도성 카본에 백금이 담지된 전극촉매를 콜로이드법을 이용하여 합성하였다. 콜로이드법 합성을 위한 백금 전구체로는 PSA (platinum sulfite acid)를 사용하였으며, 고가의 전구체를 대체하기 위해 CPA (chloroplatinic acid)를 사용하여 합성하였다. PSA를 전구체로 하여 제조한 전극촉매는 10~40 wt% 담지량에서 3.5 nm 이하의 백금 입자크기와 90% 이상의 백금 담지수율을 보였다. CPA를 전구체로 사용한 경우에는 10~40 wt% 담지량에서 4.4 nm 이하의 백금 입자 크기를 보였으며 담지수율은 80% 이상이었다. 제조한 20 wt% Pt/VXC72 전극촉매로 MEA (membrane electrode assembly)를 제조하여 I-V 곡선을 측정하였으며, 제조한 전극촉매를 이용한 막전극접합체는 상용전극촉매를 사용한 경우와 동등한 성능을 보였다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.84.1-84.1
• /
• 2010

Since the discovery of the carbon nanotube(CNTs), they have attracted much attention because of unique properties that may impact many fields of science and technology. The considerable properties of CNTs include high surface area, outstanding thermal, electrical conductivity and mechanical stability. However, uniform deposition of Pt nanoparticles on carbon surface remains inaccessible territory because of the inert carbon surface. In this study, we prepared directly oriented CNTs on carbon paper as a catalyst support in cathode electrode. carbon surface was functionalized using aryl diazonium salt for increasing adhesion of Ni particles which is precursor for growing CNTs. For fabricate electrode, CNTs on carbon paper were grown by chemical vapor deposition using Ni catalyst and Pt nanoparticles were deposited on CNTs oriented carbon paper by polyol method. The performance was measured using Proton electrolyte Membrane Fuel Cell(PEMFC). The structure and morphology of the Pt nanoparticles on CNTs were characterized by Scanning electron Microscopy(SEM) and Transmission electron Microscopy (TEM). The average diameter of Pt nanoparticles was 3nm.