Polymer-layered silicate nanocomposite membranes for fuel cell application

Fuel cells have gained increasing interest in this realm due to their promising emission-free energy generation capability. Proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) are the most suitable candidates for this purpose due to their wide range of energy generation capability. The polymer membranes used in PEMFCs and DMFCs play vital role in transporting the protons from anode to cathode. Nafion is the most widely used and commercialized membrane for this application at low-temperature and highly humidified conditions. The drawbacks associated with low-temperature PEMFCs (heat and water management, CO catalyst poisoning, and fuel crossover) can be avoided by increasing the operating temperature of the fuel cells. However, the drastic decrease in the conductivity of Nafion above 80 °C and low humidity has paved the path towards the development of new membranes and technologies. Additions of layered silicates to the polymer membranes have been observed to be beneficial in this regard owing to their high hydrophilicity, low cost, easy availability, and barrier property towards fuel crossover. The resulting composite membranes also infer improved mechanical and thermal properties, along with water uptake of the membranes escorting towards superior performance of the nanocomposite membranes at high temperature compared to the virgin membrane.