Durable membrane electrode assembly catalyst coated diffusion media with no lamination to membrane
View Patent ↗A technique for fabricating an MEA for a fuel cell that is prepared as a catalyst-coated diffusion media (CCDM). The MEA includes a diffusion media layer having a microporous layer. A catalyst layer is deposited on the microporous layer so that it covers its entire surface. An ionomer layer is sprayed on the catalyst layer. A perfluorinated membrane is sandwiched between one CCDM at the anode side of the MEA and another CCDM at the cathode side of the MEA where the ionomer spray layers face the membrane.
1. A method for making a membrane electrode assembly (MEA) for a fuel cell, said method comprising:
providing a cathode side diffusion media layer;
depositing a cathode side catalyst layer on the cathode side diffusion media layer;
spraying an ionomer layer on the cathode side catalyst layer;
providing an anode side diffusion media layer;
depositing an anode side catalyst layer on the anode side diffusion media layer;
spraying an ionomer layer on the anode side catalyst layer;
positioning the diffusion media layers at opposite sides of a membrane so that the ionomer layers faces the membrane; and
sandwiching the membrane between said ionomer coated diffusion media layers and incorporating the diffusion media layers and membrane into the fuel cell without heat-pressing said ionomer coated diffusion media layers to the membrane.
2. The method according to claim 1 wherein depositing the catalyst layers on the diffusion media layers includes depositing the catalyst layers so that they are about the same size as the diffusion media layers.
3. The method according to claim 1 further comprising providing a microporous layer as part of the diffusion media layers, where the catalyst layers are deposited on the microporous layer.
4. The method according to claim 1 wherein the membrane is a perfluorinated membrane.