Proton exchange membrane also known as polymer electrolyte membrane (PEM) is made from ionomers (polyelectrolytes) which consist of repeating units of electrically neutral and ionized groups bonded to the polymer backbone. PEM are the semi permeable membranes that allows only the transfer of protons while blocking transfer of hydrogen, oxygen or water. These membranes are widely used in PEM Fuel cells and water electrolyzers. PEM membranes are characterized by their proton conductivity, chemical & thermal stability and their strength.
In Fuel cell, PEM membranes not only enables the transfer of protons but also act as barrier layer between anode and cathode thus preventing hydrogen and oxygen to react directly resulting in generation of heat which damages the fuel cell. Therefore, durability of PEM is an utmost requirement for the efficient and longer operating life of Fuel cell.
Perfluorosulfonic acid (PFSA) polymer is the most commonly used ionomer as the proton exchange membrane which is also sold in the market under the brand name: Nafion (trademark of The Chemours Company FC, LLC). We supply, Reinforced PFSA membrane which has characteristics of high strength and high conductivity. Reinforced PFSA membranes have higher mechanical strength in comparison to un-reinforced PFSA membranes. Reinforced membranes with typical thickness in the range of 25-35 um have mechanical strength equivalent to 175 um thick un-reinforced membrane. Another advantage of the reinforced PFSA membrane is that it swells only in one direction during water-uptake in fuel cell operation thus reducing the mechanical stress at electrode-membrane interface. Detailed information about Reinforced PFSA membranes can be obtained from publication listed below:
de Bruijn, Frank A., et al. "Materials for state-of-the-art PEM fuel cells, and their suitability for operation above 100° C." Advances in fuel cells (2007): 235-336.
Srouji, Abdul-Kader, and Matthew M. Mench. "Freeze Damage to Polymer Electrolyte Fuel Cells." Polymer Electrolyte Fuel Cell Degradation (2011): 293-333.
Manthiram, A., X. Zhao, and W. Li. "Developments in membranes, catalysts and membrane electrode assemblies for direct methanol fuel cells (DMFCs)." Functional materials for sustainable energy applications. Woodhead Publishing, 2012. 312-369.
Steinberger-Wilckens, R., et al. "Performance degradation and failure mechanisms of fuel cell materials." Materials for fuel cells. Woodhead Publishing, 2008. 425-465.
|Specification of PFSA Membrane||Table|
|Tensile Strength||30 MPa (Test Method: ASTM D882)|
|Tensile Modulus||400 MPa (Test Method: ASTM D882)|
|Elongation at break||180%|
|Hydrogen Crossover||0.010 ml/min·cm²|
|Water Content||5.0±3.0 % (Test Method: ASTM D570)|
|Water Uptake||50±5.0 (Test Method: ASTM D570)|
|Thickness Change increase - 50% RH, 23°C to water soaked 23°C||10% ASTM D756|
|Thickness Change % increase - 50% RH, 23°C to water soaked 100°C||30% ASTM D756|
|Linear Expansion % increase - 50% RH, 23°C to water soaked 23°C||5% ASTM D756|
|Linear Expansion % increase - 50% RH, 23°C to water soaked 100°Ce||40% ASTM D756|