Multilayer membranes for intermediate temperature polymer electrolyte fuel cells

IT-­PEFC operating at 120°C and not the usual 80°C has many advantages, such as faster chemical reactions. If the gas humidification is reduced, simpler and lighter humidifiers can be used, leading to a reduction in the fuel cell total cost. However, at this condition the current commercial membrane Nafion is not able to hold water and perform satisfactorily. Therefore, in this study the application of multilayer membranes for IT-PEFC was investigated. These membranes were divided into two groups, a first with external layers of Nafion and an inner layer of sulphonated polyindene, and a second with external layers of Nafion and an inner layer of graphene oxide. The membrane preparation method was also investigated. The multilayer membranes were prepared by hot pressing and solution casting. As a result, cast multilayer membranes showed better performance and proton conductivity than hot pressed. Delamination and low interface interaction were the main drawbacks for hot pressed membranes. Cast multilayer sulphonated polyindene membranes showed higher performance than Nafion at 120°C and 20% of relative humidity. In the meantime, cast graphene oxide multilayer membranes showed higher water uptake and open circuit voltage than Nafion