Abstract
Gas diffusion media (GDM) based on carbon cloth material (SAATI S.p.A.) and coated with Micro Porous Layers (MPL) containing 12% or 40% PTFE were investigated. The GDMs were tested in a cell using a catalyst coated membrane (CCM) made from Nafion® 212 and with a Pt load of 0.3/0.6 mg cm-2. The test conditions were: 60 °C, flow rates of 0.2 Nl min-1 at the anode and 1.0 Nl min-1 at the cathode; relative humidity (RH) equal to 60 % or 100 % at cathode side and fixed at 80 % at the anode; the GDMs were compressed to 50 % of their initial thickness. The cell performances were assessed by analysis of the polarization curves, and the influence of PTFE loading of the MPLs on water management ability was investigated at different air RH conditions by AC impedance spectroscopy.