Fe-Ni-Cr alloy as bipolar plate of PEMFC by multi-steps surface modification

摘要

Fe-Ni-Cr alloy is a potential material as the bipolar plate for proton exchange membrane fuel cell (PEMFC). However, its interfacial contact resistance is too high and the corrosion resistance is too low to survive in the hostile environment. An approach of preparing the composite coating layers in O-2 is reported in this manuscript. The plate is first treated in acid solution, and then is heat treated in O-2 at 250 degrees C for 2 h, at last is treated by electrochemical method. The ICR for the treated plate is only 9.4 m Omega cm(2) at the compaction force of 240 N cm(-2), and corrosion current density is 4.62 x 10(-8) A cm(-2). Microstructures for differential treatments have been analyzed by FE-SEM, XPS and AES. The results indicate that high carbon concentration within surface area has been aroused by chemical treatment, and then FeO/Cr7C3 layer has been in-situ formed by heat treatment. Thereafter electro-chemical treatment has the function of clearing the FeO away and forming dense Cr2O3/Cr7C3/C layer, which improves the performance of bipolar plate effectively. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.