• Title/Summary/Keyword: Proton Exchange Membrane (PEM)

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Current Sensing Atomic Force Microscopy Study of the Morphological Variation of Hydrated Pronton Exchange Membrane (Current Sensing Atomic Force Microscopy를 이용한 PEM의 수화 현상에 따른 모폴로지 변화 연구)

  • Kwon, Osung;Lee, Sangcheol;Son, ByungRak;Lee, Dong-Ha
    • Journal of the Korean Solar Energy Society
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    • v.34 no.4
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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.

Review on Proton Exchange Membranes for Microbial Fuel Cell Application (미생물 연료 전지 적용을 위한 양성자 교환막에 대한 검토)

  • Kim, Ji Min;Patel, Rajkumar
    • Membrane Journal
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    • v.30 no.4
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    • pp.213-227
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    • 2020
  • As unrenewable energy resources have depleted over the years, the demand for renewable energy has increased promoting research for more effective methods to produce renewable energy. The field of fuel cell development, specifically microbial fuel cells (MFCs), has developed because of the dual performance potential of the technology. MFCs convert power by facilitating electrode-reducing organisms such as bacteria (microbes) as a catalyst to produce electrical energy. MFCs use domestic and industrial wastewater as fuel to initiate the process, purifying the wastewater as a result. Proton exchange membranes (PEM) play a crucial role in MFCs as a separator between the anodes and cathodes chambers allowing only protons to effectively pass through. Nafion is the commercially used PEM for MFCs, but there are many setbacks: such as cost, production time, and less effective proton conductivity properties. In this review there will be largely two parts. Firstly, several newly developed PEM are discussed as possible replacements of Nafion. Secondly, MFC based on PEM, blended PEM and composite PEM are summarized.

Fundamental Study of Unit Proton Exchange Membrane Electrolysis for Realtime Detection of Tritium (실시간 삼중수소 검출을 위한 단위 양성자 교환 막 전기분해 기초연구)

  • CHAE, JONGMIN;YU, SANGSEOK
    • Journal of Hydrogen and New Energy
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    • v.29 no.2
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    • pp.226-234
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    • 2018
  • Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.

Molecular Dynamics (MD) Study of Proton Exchange Membranes for Fuel Cells (연료전지용 수소이온 교환막의 분자동역학 연구)

  • Park, Chi Hoon;Nam, Sang Yong;Hong, Young Taik
    • Membrane Journal
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    • v.26 no.5
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    • pp.329-336
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    • 2016
  • Proton exchange membrane (PEM) is one of the key components of membrane-electrode assembly (MEA), which plays important role in fuel cell performance together with catalysts. It is widely accepted that water channel morphology inside PEMs as a proton pathway significantly affects the PEM performance. Molecular dynamics (MD) simulations are a very useful tool to understand molecular and atomic structures of materials, so that many related researches are currently being studied. In this paper, we summarize the current research trend in MD simulations, present which properties can be characterized, and finally introduce the usefulness of MD simulations to the researchers for proton exchange membranes.

Experimental studies on Flooding in the PEM Fuel Cell at various RH (상대습도 변화에 따른 PEM Fuel Cell 내에서의 플러딩에 관한 실험적 연구)

  • Kim, Kyoung-Rock;Han, Seong-Ho;Aim, Deuk-Kuen;Choi, Young-Don
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2385-2389
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    • 2008
  • This is the experimental research that tries to explain a variety of RH is how to affect the cell performance and the flooding phenomenon of proton exchange membrane fuel cell (PEMFC). A value of PH changes to 0%, 50% and 90% as its variation, either stoichiometric flow rate changes to 1.5, 2 and 4. Into the comparison between theoretical and experimental value, this study analyzes that a variety of PH is how 10 affect flooding in the cathode of the proton exchange membrane fuel cell. The effect of air stoichiometry, air humidity and different flow fields are also discussed in this paper This study has accomplished the measurement of performance as the variety of RH in the cathode of proton exchange membrane fuel cell, moreover it has recorded the visualization of flooding in the cathode with a high-speed micro camera.

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Electricity Generation and Microbial Community Structure Variation Depending on Separator Types and Cathode Characteristics in Air-cathode MFC (공기환원전극 미생물연료전지에서 분리막 종류 및 환원전극 특성에 따른 전기발생 및 미생물 군집구조 변화)

  • Yu, Jae-Cheul;Lee, Chang-Yeol;Kim, Sun-Ah;Cho, Hae-In;Cho, Sun-Ja;Lee, Tae-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.2
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    • pp.113-120
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    • 2010
  • Air-cathode microbial fuel cell consisted of 4 unit cells were operated under batch condition and electricity generation and microbial community structure variation were investigated, depending on separator types and cathode characteristics: A) PEM(Proton Exchange Membrane)-30% Wet proofing Carbon Cloth(WC), B) AEM(Anion Exchange Membrane-WC, C) CEM(Cation Exchange Membrane)-WC, D) PEM-No Wet proofing Carbon Cloth(NC). Maximum power densities of PEM-WC, AEM-WC and CEM-WC were 510.9, 522.1 and 504.8 $mW/m^2$, respectively. But PEM-NC showed relatively lower maximum power density of 218.3 $mW/m^2$. And PEM-WC, AEM-WC and CEM-WC showed similar internal resistances(20.0-28.2 ${\Omega}$). PCRDGGE, PCA and diversity indices showed that uncultured bacteria which reported in previous MFC studies were detected in suspended growth bacteria and attached growth bacteria would be affected not by separator type but by cathode characteristic. Thus, cathode characteristic can be one of the critical factors for power generation in air-cathode MFC using PEM, AEM, and CEM as separator.

Recent Progress on Proton Exchange Membrane Based Water Electrolysis (수소이온 교환막 기반 수전해의 최근 연구 동향)

  • Yang, Seungmin;Rajkumar, Patel
    • Membrane Journal
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    • v.32 no.5
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    • pp.275-282
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    • 2022
  • In contemporary days, hydrogen-based energies including batteries are renowned to be effective. And its effectiveness comes from the fact that it possesses high efficiency as an energy carrier. Eco-friendly and high purity of hydrogens comes out from water electrolysis. And among different types of electrolysis, proton exchange membrane (PEM) water electrolysis is considered the most renewable, cheap, and eco-friendly. It produces oxygen and hydrogens which are feasible in using as energies. Since it has such a number of benefits, increased research is going on in PEM electrolysis. Nafion is widely used as PEM, but high cost and various other disadvantages leads to the exploration of alternative materials. This review is broadly classified into Nafion and non Nafion based PEM for water electrolysis.

Effect of Operation Temperature on the Durability of Membrane and Electrodes in PEM Water Electrolysis (PEM 수전해에서 막과 전극의 내구성에 미치는 구동 온도의 영향)

  • Donggeun Yoo;Seongmin Kim;Byungchan Hwang;Sohyeong Oh;Kwonpil Park
    • Korean Chemical Engineering Research
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    • v.61 no.1
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    • pp.19-25
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    • 2023
  • Although a lot of research and development has been conducted on the performance improvement of PEM (Proton Exchange Membrane) water electrolysis, the research on durability is still in early stage. This study investigated effect of temperature on the water electrolysis durability when driving temperature of the PEM water electrolysis was increased to improve performance. Voltage change, I-V, CV (Cyclic Voltammetry), LSV (Linear Sweep Voltammetry), Impedance, and FER (Fluoride Emission Rate) were measured while driving under a constant current condition in a temperature range of 50~80 ℃. As the operating temperature increased, the degradation rate increased. At 50~65 ℃, the degradation of the IrO2 electrocatalyst mainly affected the durability of the PEM water electrolysis cell. At 80 ℃, the polymer membrane and electrode degradation proceeded similarly, and the short resistance decreased to 1.0 kΩ·cm2 or less, and the performance decreased to about 1/3 of the initial stage after 144 hours of operation due to the shorting phenomenon.

Effect of Electrolyte Concentration Difference on Hydrogen Production during PEM Electrolysis

  • Sun, Cheng-Wei;Hsiau, Shu-San
    • Journal of Electrochemical Science and Technology
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    • v.9 no.2
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    • pp.99-108
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    • 2018
  • Proton exchange membrane (PEM) water electrolysis systems offer several advantages over traditional technologies including higher energy efficiency, higher production rates, and more compact design. In this study, all the experiments were performed with a self-designed PEM electrolyser operated at 1 atm and $25^{\circ}C$. Two types of electrolyte were used: (i) potassium hydroxide (KOH), and (ii) sulfuric acid ($H_2SO_4$). In the experiments, the voltage, current, and time were measured. The concentration of the electrolyte significantly affected the electrolyser performance. Overall the best case was with 15 wt% $H_2SO_4$ at the anode channel and 20 wt% at the cathode channel with. In addition, increasing the difference in concentration of the sulfuric acid had an effect on the diffusion. The diffusion flux became larger when the difference in concentration became larger, increasing electrolyser efficiency without the addition of extra energy.