초록 |
A number of polymer electrolyte membranes(PEM) are studied for important technology innovation and applications in electrochmemical devices such as Polymer Electrolyte Membrane Fuel Cell (PEMFC) or Direct Methanol Fuel Cell (DMFC). Here, we would like to report the enhancement of performance of PEMFC by constructing nanochannels for ion transfer in the PEM at low temperature. Sulfonated triblock copolymer poly(styrene)-block-poly(ethylene-ran-butylene)-block-poly(styrene) (SEBS) with PS contents in 28 wt% and Mw of 118,000 are used for the construction of membrane with the nanochannels because SEBS has glassy outer blocks and rubbery inner blocks that cause microphase separation. The resulting films show highly asymmetric conductivity (0.015 S/cm to the vertical direction and no conductivity to the lateral direction) under 45 % relative humidity. PEMFC performance using sulfonated SEBS film shows about 250 mA/cm2 at 0.4V under temperature of 50℃ while Nafion show 110 mA/cm2 at 0.4V under temperature of 50℃.
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