New proposal of evaluation method for DMFC catalyst layers by means of electrochemical impedance spectroscopy

On the evaluation of catalyst layers in direct methanol fuel cell (DMFC), we applied the proposed electrochemical cell which enabled to evaluate the catalyst layers without an electrolyte solution circumstance. In addition, properties of polymer electrolytes, such as ionic conductivities inside or outside agglomerates of catalysts were evaluated separately by electrochemical impedance spectroscopy with an analysis using the proposed equivalent circuit. This method also suggested its possibility for evaluating a distribution of the electrolytes in catalyst layers.