Corrosion and conductivity behavior of titanium-doped amorphous carbon film coated SS316L in the environment of PEMFCs

Abstract

The corrosion of metal bipolar plates(BPs) in the environment of PEMFCs (proton exchange membrane fuel cells) not only increases the interfacial contact resistance (ICR) of BPs, but also poisons the proton exchange membrane and catalytic layer. In this work, different Ti-doped amorphous carbon (α-C) film were deposited on SS316L substrate though DC-balanced magnetron sputtering technology. The effect of Ti doping amount on the hybridization type and microstructure evolution mechanism of α-C film are explored, and its influence on corrosion resistance and electrical properties of the film was further evaluated. The results show that introduce Ti atoms to the α-C film can promote the sp2 hybridization and generate the low resistivity carbide phase, which decrease the ICR of the film from 5.64 mΩ/cm2 to 3.43 mΩ/cm2. More importantly, the introduction of Ti atoms can also improve the stability of the α-C film under nobler potential (1.4 V (SCE)) environment, promote the durability of the film in the service environment. The Ti-doped α-C film can be used as a modified coating of SS316L and act as candidate supplies for PEMFCs.