• Title, Summary, Keyword: Polymer electrolyte membrane

Search Result 551, Processing Time 0.045 seconds

TA Study on the Performance and the Efficiency in Polymer Electrolyte embrane Fuel Cell (고분자전해질형 연료전지의 성능해석 및 효율에 관한 연구)

  • Kim Hong-Gun;Kim Yoo-Shin;Yang Sung-Mo;Nah Seok-Chan
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.14 no.4
    • /
    • pp.75-80
    • /
    • 2005
  • An experimental study is carried out to investigate the performance and the efficiency humidifying Membrane Electrolyte Assembly and having the double-tied catalyst layers in a fuel cell system which is taken into account the physical and thermal concept. Subsequently, an electric output produced by PEMFC(Polymer Electrolyte Membrane Fuel Cell) is measured to assess the performance of a stack, and the efficiency is also evaluated according to the different situation in which unit cell is placed with and without the humidification of the MEA. It is found that the measured values of stack voltage and current are influenced by the stack temperature, humidification, and the double-tied catalyst layers which give more enhanced values to be applied to electric units.

Improving Power Conversion Efficiency and Long-term Stability Using a Multifunctional Network Polymer Membrane Electrolyte; A Novel Quasi-solid State Dye-sensitized Solar Cell

  • Gang, Gyeong-Ho;Gwon, Yeong-Su;Song, In-Yeong;Park, Seong-Hae;Park, Tae-Ho
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • /
    • pp.484.2-484.2
    • /
    • 2014
  • There are many efforts to improving the power conversion efficiencies (PCEs) of dye-sensitized solar cells (DSCs). Although DSCs have a low production cost, their low PCE and low thermal stability have limited commercial applications. This study describes the preparation of a novel multifunctional polymer gel electrolyte in which a cross-linking polymerization reaction is used to encapsulate $TiO_2$ nanoparticles toward improving the power conversion efficiency and long-term stability of a quasi-solid state DSC. A series of liquid junction dye-sensitized solar cells (DSCs) was fabricated based on polymer membrane encapsulated dye-sensitized $TiO_2$ nanoparticles, prepared using a surface-induced cross-linking polymerization reaction, to investigate the dependence of the solar cell performance on the encapsulating membrane layer thickness. The ion conductivity decreased as the membrane thickness increased; however, the long term-stability of the devices improved with increasing membrane thickness. Nanoparticles encapsulated in a thick membrane (ca. 37 nm), obtained using a 90 min polymerization time, exhibited excellent pore filling among $TiO_2$ particles. This nanoparticle layer was used to fabricate a thin-layered, quasi-solid state DSC. The thick membrane prevented short-circuit paths from forming between the counter and the $TiO_2$ electrode, thereby reducing the minimum necessary electrode separation distance. The quasi-solid state DSC yielded a high power conversion efficiency (7.6/8.1%) and excellent stability during heating at $65^{\circ}C$ over 30 days. These performance characteristics were superior to those obtained from a conventional DSC (7.5/3.5%) prepared using a $TiO_2$ active layer with the same thickness. The reduced electrode separation distance shortened the charge transport pathways, which compensated for the reduced ion conductivity in the polymer gel electrolyte. Excellent pore filling on the $TiO_2$ particles minimized the exposure of the dye to the liquid and reduced dye detachment.

  • PDF

Characteristics of Fabricated MEA(Membrane Electrode Assembly) on Polymer Electrolyte Membrane Fuel Cell Made by the Screen Printing Method (스크린 프린팅법을 이용하여 제조된 고분자 전해질 연료전지에서 MEA(조합 막 전극)의 특성)

  • 임재욱;최대규;류호진
    • Journal of the Semiconductor & Display Technology
    • /
    • v.2 no.4
    • /
    • pp.27-30
    • /
    • 2003
  • The effect of fabrication method of catalytic layer on electrode performance has been investigated. Brush, spray gun and screen printer were used as fabrication tool and catalytic layers were formed by several methods in screen printing. Direct screen printing on polymer membrane, screen printing on carbon paper, and their combined method were applied. In the electrode fabricated by the screen printing method, Pt loading of Pt/C catalysts could be cut down to 50%, compared with results by the brushing and spraying methods. The best result of electrode was obtained as 0.6 V, at 1 A/$\textrm{cm}^2$ when catalytic layer was formed by the combined way.

  • PDF

A Study on the Ion Permeability Characteristics in Nano-Polymer Membrane Structures (나노고분자막 구조의 이온투과 특성에 관한 연구)

  • Kim, Yoo-Young
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.15 no.1
    • /
    • pp.133-137
    • /
    • 2006
  • Ion permeability characteristics in nano-polymer membrane structures are performed to investigate the chemical composition and characteristics of MEA(Membrane Electrolyte Assembly) which is one of the most important parts to decide the performance in PEMFC(Polymer Electrolyte Membrane Fuel Cell) system. Subsequently, the MEA manufacturing process is presented for the uniformed MEA product. In the meantime, the analysis of SEM(Scanning Electron Microscope) is carried out in order to investigate the joint aspect and chemical composition of MEA. As a result of SEM analysis, it is found that the bonded catalyst and carbon composition contain the reasonable amount to get unit cell output. It is also found that the humidification gives the better performance result slightly.

Electrochemical Characteristics of Ion-Exchange Membrane and Charged Mosaic Membrane (복합 하전 모자이크 막과 이온교환 막의 전기적화학적 특성)

  • Yang, Wong-Kang;Song, Myung-Kwan;Cho, Young-Suk
    • Membrane Journal
    • /
    • v.17 no.1
    • /
    • pp.37-43
    • /
    • 2007
  • The effect of anionic and cationic exchange polymer layer on the chronopotentiometry (CP) and current voltage curves (I-V) of charged composite membrane are investigated. Also, the ion transport near the interface between electrolyte and ionic exchange polymer membranes (anionic and cationic ones) and charged mosaic polymer composite membrane is studied. The results show that both anionic and cationic polymer exchange membranes exhibit lower voltage drop over range of applied current density and possess favorable industrial application potentials, especially at low KCl concentration. While the charged mosaic polymer composite membrane didn't show any current-voltage change, irrespective to the type and the concentration of used electrolyte. CP and I-V measurements are effectively used to give some fundamental understanding for ion transport behavior of ion exchange polymer membrane near the interlace.

Photovoltaic Performance of Dye-sensitized Solar Cells assembled with Hybrid Composite Membrane based on Polypropylene Non-woven Matrix

  • Choi, Yeon-Jeong;Kim, Dong-Won
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.2
    • /
    • pp.605-608
    • /
    • 2011
  • Hybrid composite membranes were prepared by coating poly(ethylene oxide) and $SiO_2$ particles onto the porous polypropylene nonwoven matrix. Gel polymer electrolytes prepared by soaking the hybrid composite membranes in an organic electrolyte solution exhibited ionic conductivities higher than $1.1{\times}10^{-3}Scm^{-1}$ at room temperature. Dyesensitized solar cell (DSSC) employing the hybrid composite membrane with PEO and 10 wt % $SiO_2$ exhibited an open circuit voltage of 0.77 V and a short circuit current of 10.78 $mAcm^{-2}$ at an incident light intensity of 100 $mWcm^{-2}$, yielding a conversion efficiency of 5.2%. DSSC employing the hybrid composite membrane showed more stable photovoltaic performance than that of the DSSC assembled with liquid electrolyte.

Influence of the Catalyst Composition on Electrode Performance for Polymer Electrolyte Membrane Fuel Cells (촉매조성이 PEM용 연료전지의 전극특성에 미치는 영향)

  • 임재욱;최대규;류호진
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.9 no.3
    • /
    • pp.43-48
    • /
    • 2002
  • In this study, high performance electrode catalyst was developed in fabrication of membrane electrode assembly for PEMFCs(Polymer Electrolyte Membrane Fuel Cells). The I-V characteristics were measured to evaluate the influence of Nafion solution and Pt loading amount in the catalyst composition. The electrode characteristics were also investigated with respect to temperature change. The electrode performance was optimized at Nafion 5 wt% and 0.5 mg Pt/$\textrm{cm}^2$ content. The increase in the concentration of Nafion solution resulted in the decrease in electrode performance. At $80^{\circ}C$ of unit cell, I-V characteristics excelled those obtained at lower temperature. There was no difference in performance at low current density, but the improvement of voltage value in higher temperature could be found at high current density.

  • PDF

Sulfonated Dextran/Poly(vinyl alcohol) Polymer Electrolyte Membranes for Direct Methanol Fuel Cells

  • Won, Jong-Ok;Ahn, Su-Mi;Cho, Hyun-Dong;Ryu, Ji-Young;Ha, Heung-Yong;Kang, Yong-Soo
    • Macromolecular research
    • /
    • v.15 no.5
    • /
    • pp.459-464
    • /
    • 2007
  • Polymer electrolyte membranes, featuring ionic channels, were prepared from sulfonated dextran/ poly(vinyl alcohol) (sD/PVA) membranes. A stiff sulfated dextran was chosen as the route for ionic transport, since ionic sites are located along the stiff dextran main chain. The sD/PVA blend membranes were annealed and then chemically crosslinked. The characteristics of the crosslinked sD/PVA membranes were investigated to determine their suitability as proton exchange membranes. The proton conductivity was found to increase with increasing amounts of sD inside the membrane, which reached a maximum and then decreased when the sD content exceeded 30 wt%, while the methanol permeability increased with increasing sD content. The good dispersion of sD inside the membrane, which serves as an ionic channels mimic, played a significant role in proton transportation.

Silver Polymer Electrolyte Membranes for Facilitated Olefin Transport: Carrier Properties, Transport Mechanism and Separation Performance

  • Kim, Jong-Hak;Kang, Yong-Soo
    • Macromolecular research
    • /
    • v.12 no.2
    • /
    • pp.145-155
    • /
    • 2004
  • Facilitated transport membranes for the separation of olefin/paraffin mixtures have long been of interest in separation membrane science because olefins, such as propylene and ethylene, which are important chemicals in petrochemical industries, are currently separated by energy-intensive cryogenic distillation processes. Recently, solid polymer electrolyte membranes containing silver ions have demonstrated remarkable performance in the separation of olefin/paraffin mixtures in the solid state and, thus, they can be considered as alternatives to cryogenic distillation. Here, we review recent progress, and critical issues affecting in the use of facilitated olefin transport membranes; in particular, we provide a general overview with reference to carrier properties, transport mechanisms, and separation performance.