Corrosion-resistant component for PEM fuel cells

Thin sheets of stainless steel are low-cost material for fuel cell components that can be easily formed to yield compact volume. But corrosion of the stainless steel bipolar plates is a problem in the PEMFC. Corrosion affects the performance and cell life of a fuel cell. The goal of this study is to find out appropriate surface treatment technology to protect the stainless steel bipolar plates against electrochemical corrosion. The feasible surface treatment process should be able to make significant improvement on the corrosion-resistance and the electrical resistance at a reasonable cost. After the treatment, the surface composition and/or the surface morphology may be modified. The modification of the surface composition may improve the corrosion-resistance of the metallic bipolar plate. The corrosion rate is determined by linear-polarization method from the polarization curve. The differences in polarization behaviors are attributed to a surface treated layer. The electrical resistance is the other factor which may affect the performance of the fuel cell. A smoother surface may reduce the interfacial resistance. The treated layer is a passive film. The thickness of the passive film after the surface treatment is thinner and the surface resistance is reduced. (C) 2004 Elsevier B.V. All rights reserved.