Preparation of Membrane Electrode Assembly for Fuel Cell by Using Electrophoretic Deposition Process

A membrane electrode assembly (MEA) was prepared by electrophoretic deposition (EPD) process onto Nafion 117 membrane. A suspension consisting of ethanol, carbon powders with Pt catalyst, and Nafion polymer was used in the EPD process to obtain a stable dispersed solution. A thickness of the prepared catalyst layer was easily controlled by EPD duration or concentration of suspension. The prepared catalyst layer was well attached to the Nafion membrane. This layer was similar to that prepared by a hot press method. However, the catalyst layer consisted of only fine carbon particles was smaller and more uniform than that prepared by a hot press method. Such a uniform structure provided a high utilization of Pt catalyst. A 56% utilization of Pt catalyst loaded to the catalyst layer was successfully achieved by using the EPD method. A hydrogen-oxygen fuel cell was constructed using the MEA prepared by the EPD process. The cell exhibited a higher electrochemical performance, compared with ordinary cells.