Study of Methanol Concentration Effect in Direct Methanol Fuel Cells by Electrochemical Impedance Spectroscopy.

This paper analyzes and discusses the performance of a DMFC as a function of methanol aqueous solution concentration fed at the anode, using the Electrochemical Impedance Spectroscopy (EIS). Impedance data obtained were analyzed through the development of an equivalent circuit model. Electrochemical impedance spectroscopy was used to estimate the membrane conductivity and to model the electrochemical behavior of electrodic reactions inside the fuel cell, revealing a worse overall performance by increasing methanol concentration at the anode.