Cr2O3/C composite coatings on stainless steel 304 as bipolar plate for proton exchange membrane fuel cell

Stainless steel 304 (SS304) is a potential material as the bipolar plate for PEMFC (proton exchange membrane fuel cell). However, its interfacial contact resistance is too high and the corrosion resistance is too low to survive in the hostile environment. A novel approach of preparing the composite coating layers by in-situ method is reported in this manuscript. The plate is first treated in acid solution, and then heat treated at low temperature, finally it is treated by electrochemical method. The ICR (interfacial contact resistance) for the treated plate is 9.8 mΩ cm2 at the compaction force of 240 N cm−2, and the corrosion current density is 3 × 10−7 A cm−2. Microstructures for differential treatments have been analyzed by FESEM (field emission scanning electron microscope), XPS (X-ray photoelectron spectroscopy) and AES (Auger electron spectroscopy). The results indicate that a protectively layer with Cr2O3/carbon is formed on the SS304 surface, which improves the performance of bipolar plate effectively.