Abstract

Aluminum-based bipolar plates for proton exchange membrane (PEM) fuel cells offer high strength and durability while weighing up to 65% less than stainless steel. To protect the aluminum from electrochemical corrosion while maintaining electrical conductivity, coatings that are a composite of a fluoropolymer and one or more conductive inorganic fillers were investigated. Titanium carbide (TiC) and graphite were found to be the best candidates for conductive fillers among six powders that were tested for acid and electrochemical stability. Composite coatings of graphite, TiC, and ethylene-tetrafluoroethylene (ETFE) were applied to the aluminum or ceramic substrates by wet spraying followed by heat treatment, and then tested for in-plane sheet resistance, through-plane area specific resistance (ASR), electrochemical corrosion resistance, flexural strength, and flexibility. The composite-coated aluminum plates meet the U.S. DOE targets for bipolar plates for in-plane conductivity, flexural strength, and cathodic corrosion resistance. The targets for through-plane ASR and anodic corrosion resistance were not met due to the spraying process producing an undesirable layered microstructure and also a microstructure with connected porosity and pinholes.

Full Text
Paper version not known

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 call

Disclaimer: 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.