Surface modification and performance of inexpensive Fe-based bipolar plates for proton exchange membrane fuel cells

A reforming pack chromization with rolling pretreatment process is utilized to develop inexpensive and high-performance Fe-based metal bipolar plates (SS 420, SS 430, and SS 316 stainless steels) for PEMFC systems. Rolling process is previously performed to reduce the chromizing temperature and generate a coating possessing excellent conductivity and corrosion resistance on the steels during chromization. The power efficiencies of rolled-chromized and simple chromized bipolar plates are compared with graphite bipolar plates employed in PEMFCs. The results show that the rolled-chromized bipolar plates have a corrosion current (I-corr) of 7.87 x 10(-8) A cm(-2) and an interfacial contact resistance of 9.7 m Omega cm(2). Moreover, the power density of the single cell assembled with rolled-chromized bipolar plates is 0.46 W cm(-2), which is very close to that of graphite (0.50 W cm(-2)), in the tested conditions of this study. (C) 2010 Elsevier BM. All rights reserved.