• 한국전기화학회:학술대회논문집
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• 2002.07a
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• pp.175-178
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• 2002

• 한국전기화학회:학술대회논문집
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• 2002.04a
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• pp.43-43
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• 2002

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.195-198
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• 2004

• Clean Technology
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• v.10 no.2
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• pp.53-59
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• 2004

Direct methanol fuel cells (DMFC) are presently paid attention due to their higher energy density and portability. In order to slove problems such as high anodic overpotential and methanol crossover in DMFC, an analytical analysis for electrochemical model using Tafel equation and limiting current density was performed. Change of operational parameters such as temperature, transfer coefficients and membrane thickness results in helpful informations on voltage-current curves.

• Journal of Hydrogen and New Energy
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• v.28 no.5
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• pp.492-501
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• 2017

A 900 W scale direct methanol fuel cell (DMFC) stack is designed and fabricated for unmanned aerial vehicle (UAV) applications. To meet the volume and weight requirements, metallic bipolar plates are applied to the DMFC stack for the first time wherein POS470FC was chosen as bipolar plate material. To ensure good robustness of the metallic bipolar plate based DMFC stack, finite element method based simulations are conducted using a commercial ANSYS Fluent software. The stress buildup and deformation characteristics on bipolar plates and end plates are analyzed in details. The present DMFC stack exhibits the performance of 1,130 W at 32 V and 35.3 A, clearly demonstrating that it could successfully operate for UAVs requiring around 1,000 W of power.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.611-612
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• 2005

Fuel cells is proved that potential energy is greater than the existing power generation. In this paper, we describe a principle of fuel cell which is used for next generation portable battery and brief characteristic of direct methanol fuel cells (DMFCs) that used for portable appliances by miniaturization of polymer electrolyte fuel cell. Lastly we describe about research investment for fuel cells.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.769-774
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• 2011

Porous carbon nanofibers(CNF) were synthesized via NaOH activation at 700~$900^{\circ}C$, and the porous CNF-supported PtRu catalysts were evaluated for the anode in direct methanol fuel cells. The change of surface characteristics by NaOH activation was examined by analyses of the specific surface area and pore size distribution. The morphological and structural modification was investigated under scanning electron microscopy. The activity of catalysts supported on porous CNFs was examined by cyclic voltammograms and single cell tests. The pore formation on CNF by the NaOH activation was discussed, concerning the catalyst activity, when they were applied as catalyst supports.

• Journal of the Korean Electrochemical Society
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• v.6 no.1
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• pp.23-27
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• 2003

In this study investigations have been carried out for the evaluation of small DMFCS under passive operation conditions for use in portable powers. Under passive conditions, a maximum performance was obtained at a methanol concentration of 4 M and at a catalyst loading of $8mg/cm^2$ on both electrodes. By optimizing various parameters, we could achieve the highest performance of $55mW/cm^2$ at 1 attn and at R.T.A monopolar stack consisting of 6 unit cells with active area of $4.5cm^2/cell$ was prepared and it showed a uniform voltage distribution all over the cells and it had a power output of 1 watt and a power density of $37mW/cm^2$ A monopolar stack which consisted of 16 cells and produced a 2.4W power was also fabricated and was tested for operation of a miniature car.

• New & Renewable Energy
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• v.3 no.1 s.9
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• pp.68-74
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• 2007

The fuel cells for portable application are attracted using a liquid fuel such as methanol and chemical hydride solutions. Recently, DBFC [Direct Borohydride Fuel Cell] is a candidate for power of portable electronic devices. In this work, the anion exchange membrane and non-precious catalyst for the DBFC were concerned. Anion-exchange membrane was fabricated by amination of polysulfone followed chloromethylation. Non-precious catalysts such as raney-Ni and Ag were used as an anode and cathode catalyst. The optimum conditions of catalyst slurry mixing and MEA fabrication were developed. The single cell performance using anion exchange membrane and non-precious catalyst was evaluated and the results were compared with cation exchange membrane [Nafion membrane] and precious catalysts.

• Journal of the Korean Electrochemical Society
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• v.5 no.1
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• pp.27-29
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• 2002

We report a fuel cell power supply unit for mobile phone which operates at room temperature and ambient pressure using liquid methanol and air. The unit consists of a direct methanol fuel cell (DMFC) and a back-up battery connected parallely to the fuel cell. DMFC supplies half of the required power and the back-up battery supplies the other half during talk mode. In standby mode, DMFC covers $100\%$ of the required power and charges the back-up battery as well, Eight unit cells, each having $9 cm^2$ of active area, were connected in series in order to raise the output volotage to $2.5\~3.9V$, which is typical for most mobile phones.