Investigation of corrosion protection with conductive chromium-aluminum carbonitride coating on metallic bipolar plates

To further enhance the performance of metal bipolar plates, the CrAlCN coating with high corrosion resistance and conductivity was deposited on the SS316L substrate by using Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUMSIP) technique. Meanwhile, the inexpensive acetylene gas (C2H2) was utilized as a carbon source. XRD and XPS results indicate that the proportion of carbides in the coating increase with increasing carbon contents. Electrochemical measurements show that the C-doped coating significantly improves the corrosion resistance of the SS316L bipolar plates. The C doping enhances the conductivity of the CrAlN coating, and the C-doped sample obtains the lowest ICR value (2.94 m omega cm2, before corrosion), which is well below the DOE target (<= 10 m omega cm2). The excellent conductivity and hydrophobicity of C-doped coating increase the power density of a single cell. This study demonstrates that the CrAlCN coatings have great application prospects in the bipolar plates field.

Automated summary

In order to improve the performance of metal bipolar plates, CrAlCN coating with high corrosion resistance and conductivity was deposited on SS316L substrate using CFUMSIP technique, and cost-effective acetylene gas (C2H2) was utilized as a carbon source. XRD and XPS results showed that the proportion of carbides in the coating increased with increasing carbon contents. Electrochemical measurements demonstrated that the C-doped coating significantly enhanced the corrosion resistance of SS316L bipolar plates. The C doping improved the conductivity of the CrAlN coating, and the C-doped sample achieved the lowest ICR value (2.94 m Ωcm2, before corrosion), which was well below the DOE target (≤10 m Ωcm2). The excellent conductivity and hydrophobicity of the C-doped coating increased the power density of a single cell. This study highlights the great application prospects of CrAlCN coatings in the field of bipolar plates.