• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.79-82
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• 2005

• 한국전기화학회:학술대회논문집
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• 2001.06a
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• pp.61-64
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• 2001

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.6
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• pp.619-624
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• 2012

In this study, we demonstrated the operation of an electroosmotic pump with cylindrical porous glass frits and evaluated its long-term operation. The performance of this electroosmotic pump was characterized in terms of maximum flow rate, current, and pressure using deionized water and 1 mM borate buffer. The maximum flow rate, current, and pressure linearly increase with voltage. The maximum flow rate is normalized by the pumping area and voltage for comparison of the performance between the electroosmotic pumps with cylindrical and planar frits. The normalized maximum flow rate of the cylindrical-type pump is higher than that of the planar-type pump because of their different geometries. The cylindrical-type electroosmotic pump has five times better performance than the planartype electroosmotic pump for a given pump package volume. It can operate stably for over 3 hours.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.361-369
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• 2011

The effect of an increase in the temperature of inlet air on the performance of a membrane humidifier for a PEMFC (Polymer Electrolyte Membrane Fuel Cell) vehicle was investigated both experimentally and numerically. A shell-and-tube type gas-to-gas humidifier with Nafion membrane was tested. The experimental result showed that water transfer varies nonlinearly with the temperature elevation. Numerical analysis based on detailed modeling was also conducted in simplified geometry of a single tube to explain this nonlinear behavior. The simulation revealed that the local water flux varies nonlinearly and dramatically along the tube. The analysis was based on the inverse relationship between the increase in temperature and decrease in relative humidity, both of which seriously affect the water conductivity of the membrane.

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.57-60
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• 2004

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.151-153
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• 2008

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.540-546
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• 2010

In order to confirm the effect of Nafion ionomer content in catalyst layer on the performance of PEMFC, we have fabricated several electrodes which were prepared by varying the quantity of Nafion ionomer from 24 wt.% to 39 wt.% in catalyst layer. The effect of Nafion ionomer of each electrode was evaluated with cyclic voltammetry measurement. In addition, cell performance was obtained through single cell test using hydrogen and air. The Pt utilization and performance of single cell were changed by addition of Nafion ionomer to the electrode. Single cell fabricated with 33 wt.% of Nafion ionomer in catalyst layer showed the maximum Pt utilization and performance.

• Membrane Journal
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• v.26 no.6
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• pp.407-420
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• 2016

The fuel cell technology as a green energy source has been actively studied to solve energy shortages and pollution problems. The generating efficiency of fuel cell is high because the electricity is directly produced by using hydrogen and oxygen and the additional power generator is not needed. The key technology is the manufacturing process of polymer electrolyte membranes for polymer electrolyte membrane fuel cell (PEMFC) system. The Nafion, perfluoro-based polymeric membrane is mainly used as a polymer electrolyte membrane. However, the Nafion is expensive and rapidly decreases the performance of Nafion at high temperature. So, many researchers are lively studying new alternative electrolyte membranes. In this review, through the technology competitiveness evaluation of patents and papers, the frequencies of presentation are filed by country, institution and company. In addition, polymer electrolyte membrane fuel cell, direct methanol fuel cell and alkaline fuel cell are also filed.

• Journal of the Korean Electrochemical Society
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• v.6 no.1
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• pp.68-71
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• 2003

The performance of the Direct Methanol Fuel Cell (DMFC) using multi-layer electrode, which prepared by various anode catalysts and Nafion membranes, was studied for reducing the amount of the metal catalyst loaded in the MEA system. The amount of the catalyst used in this experiment was $3-4 mg/cm^2$ in cathode and $1-2 mg/cm^2$ in anode, respectively. The best performance was to be $230 mS/cm^2$ of MEA3 at $90^{\circ}C$ and 2 bar in this experiment. However, the overall performance of the DMFC was maintained almost the same compared to the general commercial catalyst systems.

• Membrane Journal
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• v.33 no.5
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• pp.233-239
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• 2023

The transport properties of membranes used in vanadium redox flow batteries (VRFB) are fundamental in battery performance. High proton conductivity and low vanadium ion permeability must be achieved to achieve high battery performance. However, there is a trade-off relationship between proton conductivity and vanadium ion permeability. So, solving this trade-off relationship is crucial in VRFB development. Also, maintaining high coulombic efficiency, voltage efficiency, and energy efficiency is essential for high-performing VRFB. Recently, various attempts have been made, primarily on composite membranes and SPEEK membranes, to overcome the existing limit of Nafion membranes. VRFB is an essential class of rechargeable battery in composite membranes reviewed here.