• 제목, 요약, 키워드: Polymer electrolyte membrane

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Starch-g-PAN 고분자 전해질막 합성 및 플렉서블 고체 슈퍼 캐퍼시터 응용 (Synthesis of Starch-g-PAN Polymer Electrolyte Membrane and Its Application to Flexible Solid Supercapacitors)

  • 민효준;정주환;강미소;김종학
    • 멤브레인
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    • v.29 no.3
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    • pp.164-172
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    • 2019
  • 본 연구에서는 녹말(starch)과 poly(acrylonitrile) (PAN)으로 이루어진 가지형 공중합체 기반의 슈퍼 캐퍼시터용 전해질막을 손쉽게 제조하는 방법을 제시하였다. 가지형 공중합체(starch-g-PAN)는 세륨 이온에 의해 개시된 자유 라디칼 중합을 통해 합성되었다. 실온에서 어떠한 유기용매 없이 Starch-g-PAN 고분자를 이온성 액체, 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA)에 용해하였으며 1시간 동안 $100^{\circ}C$의 고온을 가해줌으로써 손쉽게 고분자 막을 만들었다. 제조된 막은 유연하여 플렉서블 고체 슈퍼 캐퍼시터의 전해질에 적용되었다. Starch-g-PAN 기반의 고분자 전해질막을 사용한 슈퍼 캐퍼시터는 0.5 A/g의 전류 밀도에서 약 21 F/g의 정전용량을 가졌으며 10,000 사이클 동안 86%의 유지율을 보이며 높은 주기 안정성을 보였다. 본 연구를 통해 starch-g-PAN 기반의 고분자 전해질막이 우수한 성능을 가진 플렉서블 고체 슈퍼 캐퍼시터에 응용될 수 있음을 확인하였다.

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.

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.

고체 알칼리 연료전지용 음이온 교환 세공충진막의 제조 및 특성 (Preparation of pore-filling membranes for polymer electrolyte fuel cells and their cell performances)

  • 최영우;박구곤;임성대;이미순;양태현;김창수
    • 한국신재생에너지학회:학술대회논문집
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    • pp.150-153
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    • 2009
  • Anion exchange polymer electrolyte pore-filling membranes consisting of the whole hydrocarbon materials were prepared by photo polymerization with various quaternary ammonium cationic monomers and characterized on the properties for applying to solid alkali fuel cell (SAFC). Hydrocarbon porous substrates such as polyethylene were used for the preparation of the pore-filling membranes. The hydroxyl ion conductivity of the polymer electrolyte membranes prepared in this research was dependent on the composition ratio of an electrolyte monomer and crosslinking agents used for polymerization. Furthermore, these pore-filling membranes have commonly excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lower fuel crossover through the membranes, and easier preparation process than those of traditional cast membranes.

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Performance Evaluation of Platinum Dispersed Self-humidifying Polymer Electrolyte Membrane Prepared by Using RF Magnetron Sputter

  • Kwak, Sang-Hee;Yang, Tae-Hyun;Kim, Chang-Soo;Yoon, Ki-Hyun
    • 한국세라믹학회지
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    • v.40 no.2
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    • pp.118-122
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    • 2003
  • The performance evaluation on Pt loading in the self-humidifying polymer electrolyte membrane for Polymer Electrolyte Mem-Brane Fuel Cell(PEMFC) was investigated by using single cell test and measurement of membrane resistance. The self-humidifying membrane comprised two membranes made of perfluorosulfonylfluroride copolymer resin and fine Pt particles tying between them, coated by sputtering. From the results of performance characteristics of self-humidifying membrane cell with different Pt loading, a single cell using self-humidifying membrane with 0.15 mg/$\textrm{cm}^2$ Pt loading showed better performance than that with the others over entire current density. Also, a single cell with 0.15 mg/$\textrm{cm}^2$ Pt loading had a lower resistance value than the other cells under externally nonhumidifying condition. It is indicated that the water produced in the membrane cell with 0.15 mg/$\textrm{cm}^2$ Pt loading showed a higher provision to maintain ionic conductivity of the membrane than the other cells. The optimum amount of Pt particles embedded in the membrane for self-humidifying PEMFC was determined to be about 0.15 mg/$\textrm{cm}^2$.

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.

동결/해동 조건에서 고분자막의 특성 변화 연구 (PROPERTY CHANGES OF POLYMER ELECTROLYTE MEMBRANES WITH FREEZE/THAW CYCLES)

  • 박구곤;임남윤;손영준;박진수;이원용;김세훈;임태원;김창수
    • 한국신재생에너지학회:학술대회논문집
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    • pp.281-283
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    • 2005
  • Water management in polymer electrolyte membrane fuel cells(PEMFCs) is one of the most challenging issues. Freeze start-up in the automotive applications is also important research topic in the PEMFC field. Transportation of proton and separation of reactant gases are main roles of polymer electrolyte membranes. It has been known that water in the membrane conducts as a vehicle for the proton transportation. At sub-zero temperature, the frozen water blocks the access of reactant gases to the active sites of electrode as well as occurs the physical destruction of fuel cell structures. In this study, property changes of electrolyte membranes in the freeze conditions $(at\;-25^{\circ}C)$ were investigated. For the various amount of water contained membranes, the property changes, especially for the proton conductivity, were observed after several times of freeze/thaw$(-25\~80^{\circ}C)$ cycle.

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