Multilayer membrane for IT-PEFC

Polymer Electrolyte Fuel Cells (PEFCs) operate at around 80 °C and face problems like water and heat management due to these operating conditions. It is well accepted that the performance of PEFCs can be improved by operating at higher temperatures (80< T ≤120 °C). This is because operation at higher temperature will accelerate the rate of the chemical reaction, facilitate water and heat management. These are normally referred to as Intermediate Temperature Polymer Electrolyte Fuel Cells (IT-PEFC) in order to differentiate them from high temperature (T = 180 °C). However, the polymer membrane used in IT-PEFC conditions must be able to hold the water at these higher temperatures in order to transport the protons. This is not the case with the standard commercial Nafion membrane when operating over 100 °C. The present study investigates the use of multilayered membranes (MM) using Nafion and sulphonated polyindene (SPInd). Two different types of MM membranes were made: i) N/SPInd/N and ii) N/N. The component membrane single layers were cast using the polymeric solutions separately and then the layers were hot-pressed together. Characterization of the membranes using water uptake, ion exchange capacity (IEC), FT-IR and electron microscopy revealed that the water uptake for N/SPInd/N is higher than that of Nafion while the IEC is equivalent to cast Nafion. The proton conductivity test was also carried out to confirm the performance of the membranes.