Performance of the direct methanol fuel cell with radiation-grafted polymer membranes

This paper reports performance data for the direct methanol fuel cell (DMFC) using membrane electrode assemblies using radiation-grafted proton exchange membranes based on polyethylene and ETFE. These membranes exhibited low methanol diffusion coefficients and were thus felt to be potentially useful in reducing possible methanol cross-over from anode to cathode. The membrane electrode assemblies were based on Nafion®-bonded carbon-supported catalyst; platinum/ruthenium for the anode and platinum for the cathode. The cell voltage performance of the DMFC, for short duration (<100 h) testing, with these low cost membranes is as good as, or superior to, that of cells based on Nafion® under identical operating conditions. However, the stability of contact between the membrane and the catalyst layer requires improvement before these membranes become real alternatives to materials such as Nafion®, for the DMFC.