Electrochemical Impedance Spectroscopy Study of a Flowing Electrolyte-Direct Methanol Fuel Cell

Flowing electrolyte-direct methanol fuel cells (FE-DMFCs) have a second proton-exchange membrane (PEM), and a flowing electrolyte channel (FEC) in addition to the standard components found in direct methanol fuel cells (DMFCs). These additional components cause increased ohmic losses that contribute to voltage drop and performance degradation of an operating cell. Electrochemical impedance spectroscopy (EIS) was used as a diagnostic tool to investigate these losses while varying FEC thickness and the torque used to clamp the cell together. The results from this study show that increasing the thickness of the FEC and the clamping torque caused an increase in impedance. Reasons are suggested to explain these results.