This study proposes a novel gradient CreNeC multilayer film on 0.1 mm thick SS316L sheet as bipolar plates by CFUBMSIP method.Thetotalthicknessofthefilmisabout1.523mmandit
is mainly composed of Cr layer, CreN layer, CreNeC coexis-tence layer, and a-C layer. The adhesion strength between the film and SS316L substrate reaches 94.8 N due to the excellent adhesion of CrN and low interfacial stress by gradient layer. Static water contact angle of the film is 89.4 and is beneficial to water management in the PEMFCs stack. ICR between the coated SS316L sheets and TGP-H-060 carbon paper is only 2.64 mU cm2 at 1.4 MPa due to high content of C-sp2 bond in a-
C layer. The corrosionpotential of coated samples is 0.242 V vs
SCE in anodic environment and the passivation current density is 0.61 mA cm2 at 0.6 V in simulated cathodic envi-ronment. Potentiostatic test, ICP-MS measurement and SEM results unequivocally reveal that the substrate is well pro-tected by the gradient CreNeC multilayer film. Both the electrical conductivity and corrosion resistance obtain performanceimprovement and meet the DOE’s 2020 technical targets. Furthermore, the coating process parameters, which determine the film composition, can be further optimized for higher performance. The in-situ performance of CreNeC film is currently under study and the results will be reported in the near future.