• Title/Summary/Keyword: Polymer electrolyte membrane

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Repetitive bending test of membrane electrode assembly for bendable polymer electrolyte membrane fuel cell

  • Kang, Yun Sik;Park, Taehyun;Jang, Segeun;Choi, Mansoo;Yoo, Sung Jong;Cha, Suk Won
    • Journal of Industrial and Engineering Chemistry
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    • v.47
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    • pp.323-328
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    • 2017
  • Membrane electrode assemblies (MEAs) with carbon paper and cloth for bendable polymer electrolyte membrane fuel cell were characterized as it is subject to repetitive bending. The performance of the MEA with carbon paper was decreased significantly while the MEA with carbon cloth remained constant after repetitive bending. Electrochemical impedance spectroscopy revealed ohmic and charge transfer resistances of the MEA with carbon paper were increased by repetitive bending. Such performance degradation is due to physically observed damages in carbon paper and its detachment from the MEA, which was not in the MEA with carbon cloth due to its intrinsic flexibility.

An Experimental Analysis of the Ripple Current Applied Variable Frequency Characteristic in a Polymer Electrolyte Membrane Fuel Cell

  • Kim, Jong-Hoon;Jang, Min-Ho;Choe, Jun-Seok;Kim, Do-Young;Tak, Yong-Sug;Cho, Bo-Hyung
    • Journal of Power Electronics
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    • v.11 no.1
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    • pp.82-89
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    • 2011
  • Differences in the frequency characteristic applied to a ripple current may shorten fuel cell life span and worsen the fuel efficiency. Therefore, this paper presents an experimental analysis of the ripple current applied variable frequency characteristic in a polymer electrolyte membrane fuel cell (PEMFC). This paper provides the first attempt to examine the impact of ripple current through immediate measurements on a single cell test. After cycling for hours at three frequencies, each polarization and impedance curve is obtained and compared with those of a fuel cell. Through experimental results, it can be absolutely concluded that low frequency ripple current leads to long-term degradation of a fuel cell. Three different PEMFC failures such as membrane dehydration, flooding and carbon monoxide (CO) poisoning that lead to an increase in the impedance magnitude at low frequencies are simply introduced.

Investigation of Water Transport in Newly Developed Micro Porous Layers for Polymer Electrolyte Membrane Fuel Cells

  • Alrwashdeh, Saad S.;Markotter, Henning;Haussmann, Jan;Hilger, Andre;Klages, Merle;Muller, Bernd R.;Kupsch, Andreas;Riesemeier, Heinrich;Scholta, Joachim;Manke, Ingo
    • Applied Microscopy
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    • v.47 no.3
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    • pp.101-104
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    • 2017
  • In this investigation, synchrotron X-ray imaging was used to investigate the water distribution inside newly developed gas diffusion media in polymer electrolyte membrane fuel cells. In-situ radiography was used to reveal the relationship between the structure of the microporous layer (MPL) and the water flow in a newly developed MPL equipped with randomly arranged holes. A strong influence of these holes on the overall water transport was found. This contribution provides a brief overview to some of our recent activities on this research field.

Hot-Pressing Effects on Polymer Electrolyte Membrane Investigated by 2H NMR Spectroscopy

  • Lee, Sang Man;Han, Oc Hee
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.510-514
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    • 2013
  • The structural change of Nafion polymer electrolyte membrane (PEM) induced by hot-pressing, which is one of the representative procedures for preparing membrane-electrode-assembly for low temperature fuel cells, was investigated by $^2H$ nuclear magnetic resonance (NMR) spectroscopy. The hydrophilic channels were asymmetrically flattened and more aligned in the membrane plane than along the hot-pressing direction. The average O-$^2H$ director of $^2H_2O$ in polymer electrolyte membrane was employed to extract the structural information from the $^2H$ NMR peak splitting data. The dependence of $^2H$ NMR data on water contents was systematically analyzed for the first time. The approach presented here can be used to understand the chemicals' behavior in nano-spaces, especially those reshaping and functioning interactively with the chemicals in the wet and/or mixed state.

A study on the application of Residential Polymer Electrolyte Membrane Fuel Cell (가정용 고분자 전해질 연료전지 시스템의 적용에 관한 연구)

  • Lee, Cheol-Ki;Kim, Ju-Young;Hong, Won-Hwa
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • pp.315-318
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    • 2005
  • One of the problems in using renewable energy sources is great difficulty of stable and sustainable supply. Because the fuel cell can provide stable and sustainable supply of energy sources without regard to external conditions, however, it will become one of the most useful renewable energy sources for buildings that need stable energy supply. For practical application of PEMFC system to common household, the data of household energy consumption are analyzed by electricity, cooking and heating. From the result of the data analysis, practical application methods of PEMFC system to household are designed to several models. The aim of this study is to establish a plan of practical application for applying Polymer Electrolyte Membrane Fuel Cell(PEMFC) system to the households.

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Electrochemical Properties of Novel Metal Powder Electrodes for Polymer Electrolyte Membrane Electrolysis

  • Kim, Chang-Hee;Kang, Kyung-Soo;Park, Chu-Sik;Hwang, Gab-Jin;Bae, Ki-Kwang
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • pp.1227-1228
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    • 2006
  • The electrochemical properties of novel metal powders were investigated for the electrode materias of polymer electrolyte memebrane electrolysis. Two types of Pt black and $IrO_2$ powder electrodes were hot-pressed on the polymer electrolyte membrane to form membrane electrode assembly. The galvanodynamic polarization methode was used to characterize the electrochemical properties of both electrodes. From the experimental results, we concluded that the $IrO_2$ powder electrode exhibits better electrochemical performance than Pt black as cathode material for the electrolysis.

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Performance Analysis of Polymer Electrolyte Membrane Fuel Cell by AC Impedance Measurement (교류 임피던스 측정법을 이용한 고분자 전해질 연료전지의 성능특성 분석)

  • Seo, Sang-Hern;Lee, Chang-Sik
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.4
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    • pp.283-290
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    • 2009
  • This study focuses on the performance characteristics of polymer electrolyte membrane fuel cell (PEMFC) using the AC impedance technique. The experiment was carried out to investigate the optimal operating conditions of PEMFC such as cell temperature, flow rate, humidified temperature and back-pressure. The fuel cell performance was analyzed by DC electronic-loader with constant voltage mode and expressed by voltage-current density. Additionally, AC impedance was measured to analysis of ohmic and activation loss and expressed by Nyquist plot. The results showed that the cell performance increased with increase of cell temperature, air flow rate, humidified temperature and backpressure. Also, the activation loss decreased as the increase of cell temperature, air flow rate, humidified temperature and backpressure.

Research of Cross-linked Hydrocarbon based Polymer Electrolyte Membranes for Polymer Electrolyte Membrane Fuel Cell Applications (고분자 전해질 막 연료전지 응용을 위한 탄화수소계 기반 가교 전해질 막의 연구동향)

  • Ko, Hansol;Kim, Mijeong;Nam, Sang Yong;Kim, Kihyun
    • Membrane Journal
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    • v.30 no.6
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    • pp.395-408
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    • 2020
  • Polymer electrolyte membrane fuel cells (PEMFCs) have gained much attention as eco-friendly energy conversion devices without emission of environmental pollutant. Polymer electrolyte membrane (PEM) that can transfer proton from anode to cathode and also prevent fuel cross-over has been regarded as a key component of PEMFCs. Although perfluorinated polymer membranes such as Nafion® were already commercialized in PEMFCs, their high cost and toxic byproduct generated by degradation have still limited the wide spread of PEMFCs. To overcome these issues, development of hydrocarbon based PEMs have been studied. Incorporation of cross-linked structure into the hydrocarbon based PEM system has been reported to fabricate the PEMs showing both high proton conductivity and outstanding physicochemical stability. This study focused on the various cross-linking strategies to the preparation of cross-linked PEMs based on hydrocarbon polymers with ion conducting groups for application in PEMFCs.

Impedance analysis of electrochemical systems using an ion-conducting polymer electrolyte membrane (전도성 고분자 전해질막을 이용하는 전기화학적 시스템의 임피던스 해석)

  • Park, Jin-Soo;Moon, Seung-Hyeon;Kim, Chang-Soo
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.1-8
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    • 2004
  • Ion-conducting polymer electrolyte membranes (PEMs) have recently used in developing fuel cell or solar cell for portable, mobile and residential applications [1]. Polymer electrolyte membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC), alkaline electrolyte fuel cell (AFC) and dye-sensitized solar cell have been employing the ion-conducting PEMs to complete their electrical circuits to produce electricity.(omitted)

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Preparation of Gel Polymer Electrolyte Membranes of Polyvinyl Alcohol and Poly (acrylic acid) for Zn Air Batteries (아연공기전지를 위한 Polyvinyl Alcohol과 Poly (acrylic acid)의 블랜드를 이용한 겔 고분자 전해질막의 제조)

  • Kim, Chanhoon;Koo, Ja-Kyung
    • Membrane Journal
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    • v.22 no.3
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    • pp.208-215
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    • 2012
  • Gel polymer electrolyte membranes were prepared from blends of polyvinyl alcohol (PVA) and poly (acrylic acid) (PAA), by solution-cast technique. The PAA content in the blend varied from 30 to 80 wt%. With the gel polymer electrolyte membranes, Zn air batteries were fabricated. The gel polymer electrolyte membranes were characterized by means of stress-strain test, impedance test. The Zn air batteries were tested by current interrupt method and galvanostatic discharge method. The tensile strength and tensile modulus decreased with increasing PAA content in the gel polymer electrolyte membrane. On the other hand, the ionic conductivity increased with increasing PAA content. The effect of ionic conductivity trend of the gel polymer electrolyte membrane in the Zn air battery was confirmed through current interrupt method and galvanostatic discharge method experiments. The battery with higher PAA content gel polymer electrolyte membrane showed lower IR drop and higher discharge capacity.