Abstract
Polymer electrolytes based on block copolymers are considered promising proton exchange membrane (PEM) materials for fuel cell applications. A new class of block copolymers of perfluorocyclobutane (PFCB) units with pendant side chains containing sulfonic acid groups have recently been developed and studied for fuel cell applications. In order to enhance the membrane mechanical and hydrothermal stability, sulfonated PFCB copolymers are blended with fluoropolymers such as poly(vinylidene fluoride) (PVDF). Membrane fundamental properties (e.g., proton conductivity, gas permeability, water uptake) and fuel cell performance and durability were evaluated as a function of PVDF content. The proton conductivity and fuel cell performance only decrease slightly with PVDF content at PVDF blend levels of up to 30wt.%. However, at the PVDF levels higher than 40wt.%, the proton conductivity and fuel cell performance decrease rapidly with increasing PVDF content. The PFCB/PVDF composite membranes have lower hydrogen, oxygen and nitrogen gas permeability as well as a higher ratio of conductivity to permeability than perfluorosulfonic acid PFSA membranes (e.g., Nafion®). Membrane hydrothermal swelling is significantly reduced by blending sulfonated PFCB with PVDF. This reduced swelling leads to improved membrane mechanical durability as measured by increased lifetimes in RH cycling tests with increasing PVDF content.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
