Electrochemical Behavior and Surface Conductivity of C/TiC Nanocomposite Coating on Titanium for PEMFC Bipolar Plate

Abstract

In this study, a C/TiC nanocomposite coating has been prepared by magnetron sputtering technology and vacuum heat treatment technology on a titanium surface, which is used for bipolar plates (BPs) in a proton exchange membrane fuel cell (PEMFC). This prepared C/TiC nanocomposite coating was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, electrochemical testing and interfacial contact resistance (ICR). The results show that a C/TiC nanocomposite coating consists of a single C surface layer (~28.88 nm) and TiC interface layer (~19.5 nm). In addition, compared with commercially pure titanium substrate (icorr = 345.10 μA cm−2), the corrosion resistance of a C/TiC nanocomposite coating (icorr = 0.74 μA cm−2) was greatly improved in 0.5 M H2SO4 + 5 ppm HF solution at 80 °C. The corrosion current density (icorr) decreased 3 orders of magnitude in a simulated cathodic environment. Moreover, the interfacial contact resistance of a C/TiC nanocomposite coating is 2.34 mΩ cm2 under 1.4 MPa compaction force, which is much lower than that of raw CP Ti (38.66 mΩ cm2).

Porous Transport Layers with TiC-Coated Microporous Layers for Proton Exchange Membrane Water Electrolysis

“…We observed that the potentiodynamic polarization curves of PTL-MPL1 were similar to those of PTL-R. PTL-MPL1-S displayed the highest corrosion potential and the lowest corrosion current among the three samples, suggesting enhanced corrosion resistance. In the anode region, with the increase of corrosion potential, the three samples developed the activation, passivation transition, and passivation region (−0.4 to −0.2 V) . The potentiostatic polarization experiments (Figure B) showed that PTL-MPL1-S had the lowest current density.…”

“…In the anode region, with the increase of corrosion potential, the three samples developed the activation, passivation transition, and passivation region (−0.4 to −0.2 V). 38 The potentiostatic polarization experiments (Figure 9B) showed that PTL-MPL1-S had the lowest current density. At 0.2 V vs SCE, the corrosion current densities of PTL-R and MPL-MPL1 were not stable over time, while the stability of PTL-MPL1-S was improved.…”

“…TiC exhibits great corrosion resistance and high conductivity, which has attracted much attention in the field of material coating. For example, it is often employed as the protective coating in the bipolar plates in proton exchange membrane fuel cells. − The formation of the TiC-coated MPL was analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The morphology, pore diameter, and porosity of the MPL were characterized by ex situ testing.…”

Improvement in Corrosion Resistance and Interfacial Contact Resistance Properties of 316L Stainless Steel by Coating with Cr, Ti Co-Doped Amorphous Carbon Films in the Environment of the PEMFCs

“…However, in PEMFC applications, amorphous carbon film-coated bipolar plates always become damaged during stack operation due to the unavoidable coating corrosion deterioration and increased ICR. Many researchers have tried to retard the film damage by doping elements into pure amorphous carbon films [ 20 , 21 , 22 , 23 ]. The multiple elements of the amorphous carbon films may have a severe impact on the performance of the sputtering coating.…”

Micromorphology, Microstructure, and Wear Behavior of AISI 1045 Steels Irregular Texture Fabricated by Ultrasonic Strengthening Grinding Process

“…Therefore, it is necessary to enhance the antiwear properties of the contact surfaces to prevent them from experiencing dry frictional wear. Many solutions have been proposed to address this issue, such as surface alloying [4], surface coating [5,6], surface texturing [7,8], and surface nanocrystallization [9,10]. Surface texturing has emerged as a promising solution in recent decades [11][12][13][14].…”