Abstract: The stainless steel as bipolar plate has been widely used on polymer electrolyte membrane fuel cell(PEMFC) for its conductivity and anti-corrosion properties. Because of the acid environment in PEMFC, in order to further improve the service life, 316L stainless steel is put in the mixed conductive and acidic solution for surface chemical modification. The results indicate that, the contact resistance of 316L SS after passivation can reach 18.5 mΩ•cm2 at least when the pressure achieves 9×105 Pa. Comparing with the 316L SS before passivation, its contact resistance decreases nearly 6 times while the corrosive current changes slightly. Dynamic potential polarization plot shows that, after passivation, the stainless steel improves its self-corrosion potential obviously. A lot of holes can be seen distributing on the surface of the steel under the apparatus of super depth microscope. But after passivation, most of the holes are mantled.

Key words: Anti-corrosion, Bipolar plate, Contact surface resistance, Stainless steel