Development of an advanced MEA to use high-concentration methanol fuel in a direct methanol fuel cell system

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• 作者：Kyungmun Kang ; Giyong Lee ; Geonhui Gwak ; Yongjun Choi ; Hyunchul Ju ; ^{hcju@inha.ac.kr}
• 关键词：Direct methanol fuel cell ; Micro-porous layer ; Methanol crossover ; High-concentration methanol fuel ; Air humidification
• 刊名：International Journal of Hydrogen Energy
• 出版年：2012
• 出版时间：April, 2012
• 年：2012
• 卷：37
• 期：7
• 页码：6285-6291
• 全文大小：1217 K

文摘

Despite serious methanol crossover issues in Direct Methanol Fuel Cells (DMFCs), the use of high-concentration methanol fuel is highly demanded to improve the energy density of passive fuel DMFC systems for portable applications. In this paper, the effects of a hydrophobic anode micro-porous layer (MPL) and cathode air humidification are experimentally studied as a function of the methanol-feed concentration. It is found in polarization tests that the anode MPL dramatically influences cell performance, positively under high-concentration methanol-feed but negatively under low-concentration methanol-feed, which indicates that methanol transport in the anode is considerably altered by the presence of the anode MPL. In addition, the experimental data show that cathode air humidification has a beneficial effect on cell performance due to the enhanced backflow of water from the cathode to the anode and the subsequent dilution of the methanol concentration in the anode catalyst layer. Using an advanced membrane electrode assembly (MEA) with the anode MPL and cathode air humidification, we report that the maximum power density of 78?mW/cm² is achieved at a methanol-feed concentration of 8?M and cell operating temperature of 60?¡ãC. This paper illustrates that the anode MPL and cathode air humidification are key factors to successfully operate a DMFC with high-concentration methanol fuel.