Study On Corrosion Resistance And Electrical Conductivity Of N-Doped And Cr/N Co-Doped DLC Film Deposited On Stainless Steel Surface

Proton exchange membrane fuel cells?PEMFC?have many superior properties and are considered to be one of the most promising green high-efficiency power generation technologies.Bipolar plates are an important part of them,which have a certain impact on battery performance and preparation costs.The stainless steel bipolar plate has the advantages of high strength,good electric heat conduction performance,low cost and abundant resources,and can better increase the specific power of the fuel cell.However,in the operating environment of a fuel cell,stainless steel materials may have corrosion problems such as surface passivation or dissolution.Therefore,it is necessary to surface-treat the stainless steel bipolar plate to develop its corrosion resistance and conductivity propterties.Diamond-like diamonds have excellent chemical stability and can be used to prepare corrosion-resistant coatings.Element doping in a diamond-like carbon film can make it have better electrical conductivity,but in the application of stainless steel bipolar plate protection,the conductivity of the diamond-like film needs to be further optimized.In order to obtain a diamond-like film with both good electrical conductivity and high corrosion resistance,N-doped and Cr/N were deposited on stainless steel 316L and silicon wafer by adjusting experimental process parameters?nitrogen flow rate and Cr target power?.Co-doped diamond-like carbon film.The working environment of proton exchange membrane fuel cell?PEMFC?was simulated,and the electrical properties and corrosion resistance of uncoated samples and coated samples were studied.The main results are as follows:1 Scanning electron microscopy?SEM?results show that the surface of the chromium-nitrogen co-doped DLC film is more uniform.Through the analysis of X-ray photoelectron spectroscopy?XPS?and X-ray diffraction?XRD?results,it was found that the Cr/N co-deposited DLC film is a combination of amorphous C,CrC,CN,Cr₂N and nanocrystalline CrN.2 Contact resistance tests show that the Cr/N co-doped DLC film?Cr target power90W?has the best conductivity?9.20 m?cm² at 140 N/cm² pressure?.3 The dynamic potential polarization test shows that the corrosion resistance(corrosion current density of E^-6E-7A/cm²)of N-doped DLC and Cr/N co-doped DLC films is better than that of undoped 316L stainless steel.In summary,the Cr/N co-doped DLC film?Cr target power 90W?exhibits excellent performance in both electrical conductivity and corrosion resistance,and can be applied to the surface treatment of stainless steel bipolar plates.