Water Transport Properties of Plasma-Modified Commercial Anion-Exchange Membrane for Solid Alkaline Fuel Cells

Abstract

In the field of low-temperature fuel cells, solid alkaline membrane fuel cells (SAMFCs) appear to be a very promising new fuel cell technology. Nevertheless, commercial hydroxyl-exchange membranes suitable for SAMFCs suffer from some limitations, especially low retention to water at the cathode (where water is required to be reactive in the electrochemical reaction), which weakens fuel cell performances. In this study, the commercial Morgan ADP membrane by Solvay has been modified on the surface by plasma processes using argon or argon/triallylamine as gaseous phases. Plasma-treated and untreated membranes have been characterized in terms of water sorption and diffusion properties performing water vapor sorption measurements. Analysis of sorption isotherms and related modeling from Park model has shown that plasma treatments induce a decrease in water sorption and diffusion abilities without qualitatively affecting the water transport properties. Plasma modification from triallylamine leading to the deposition of a highly cross-linked film on the membrane surface is more influent than argon plasma treatment, causing surface physical cross-linking coupled to hydrophilization effect