Influence of Proton Exchange Membrane Preconditioning Methods on the PEM Fuel Cell Performance

Polymeric cation exchange membranes (PEM) are used in fuel cell technology. These membrane, act like a physical barrier between anode and cathode but the diffusion through membrane should allow the transport of protons from anode to cathode at a rate enough to requirements for supplying energy. Membrane has to be conditioned before use to improve performance. Chemical conditioning changes membrane counterion group and modifies its water content which affects to the diffusion coefficients. In order to analyse and quantify the effect of conditioning techniques on membrane performance various experiments with Nafion 117 cation exchange membrane were carried out. Some conditioning methods were carried out at room temperature and others at higher temperatures. Water content was followed through measuring membrane swelling. Then, treated membranes were tested in a PEM fuel cell. The different membrane-electrodes were tested and polarization curves, impedance spectroscopy and lineal and cyclic voltammetries were carried out. Acid conditions and high temperatures around 80 degrees C, used for preconditioning membranes, favoured maximum power obtained in a fuel cell up to 6 times that of a commercial supply.