Composites of Proton-Conducting Polymer Electrolyte Membrane in Direct Methanol Fuel Cells

Fuel cells are a replacement for the conventional energy resources. As early as 1839, William Grove discovered the basic operating principle of fuel cells by reversing water electrolysis to generate electricity from hydrogen and oxygen. A Direct Methanol Fuel Cell (DMFC) operates on liquid fuel, which is one of the exciting varieties of fuel cells. There are many problems with DMFCs such as the high cost of electrolyte membranes, high platinum loading, CO poisoning, fuel cross-over, and so on. In this review, research regarding the solution of these problems will be cited and discussed. The electrical performance (in respect to power density) of the composites for the Nafion® and other perfluorinated membranes in DMFC are evaluated. The effect of these modifications on various aspects, such as mobility of protons through the membrane, permeation of hydronium ions, and cross-over of methanol through the membrane leading to the negative potential, have previously been discussed. Therefore, the main focus of this review is on the effect of composites of Nafion® and non-fluorinated membranes on the DMFC performance.