• Title, Summary, Keyword: Polymer electrolyte membrane

Search Result 560, Processing Time 0.031 seconds

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

  • Min, Hyo Jun;Jung, Joo Hwan;Kang, Miso;Kim, Jong Hak
    • Membrane Journal
    • /
    • v.29 no.3
    • /
    • pp.164-172
    • /
    • 2019
  • In this work, we demonstrate a facile process to prepare an electrolyte membrane for the supercapacitor based on a graft copolymer consisting of starch and poly(acrylonitrile) (PAN). The graft copolymer (starch-g-PAN) was synthesized via free radical polymerization initiated by ceric ions. The starch-g-PAN was dissolved in ionic liquid, i.e. 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA) without any organic solvents at room temperature. The gelation of polymer electrolyte membranes occurred by applying high temperature, i.e. $100^{\circ}C$ for 1 hour. The resultant electrolyte membrane was flexible and thus applied to flexible solid supercapacitors. The performance of the supercapacitor based on starch-g-PAN graft copolymer electrolyte reached 21 F/g at a current density of 0.5 A/g. The cell also showed high cyclic stability with 86% of retention rate within 10,000 cycles. The preparation of starch-g-PAN based polymer electrolyte membrane provides opportunities for facile fabrication of flexible solid supercapacitors with good performance.

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
    • /
    • v.47
    • /
    • pp.323-328
    • /
    • 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
    • /
    • v.34 no.2
    • /
    • pp.510-514
    • /
    • 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.

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

  • Choi, Young-Woo;Park, Gu-Gon;Yim, Sung-Dae;Lee, Mi-Soon;Yang, Tae-Hyun;Kim, Chang-Soo
    • 한국신재생에너지학회:학술대회논문집
    • /
    • /
    • pp.150-153
    • /
    • 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.

  • PDF

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
    • Journal of the Korean Ceramic Society
    • /
    • v.40 no.2
    • /
    • pp.118-122
    • /
    • 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
    • /
    • v.11 no.1
    • /
    • pp.82-89
    • /
    • 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.

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

  • Park Gu-Gon;Lim Nam-Yun;Sohn Young-Jun;Park Jin-Soo;Lee Won-Yong;Kim Sae-Hoon;Lim Tae-Won;Kim Chang-Soo
    • 한국신재생에너지학회:학술대회논문집
    • /
    • /
    • pp.281-283
    • /
    • 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.

  • PDF