Electrochemical properties of TiN coatings on 316L stainless steel separator for polymer electrolyte membrane fuel cell

• Published in: Thin solid films 2008-04, Vol.516 (11), p.3669-3672
• Main Authors: Jeon, W.-S., Kim, J.-G., Kim, Y.-J., Han, J.-G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrochemical impedance spectroscopy; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; PEMFC; Physics; Potentiodynamic test; TiN
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2007.08.086

TiN films for metallic bipolar plates were synthesized by closed-field unbalanced magnetron sputtering (CFUBM) and the properties were controlled by adjusting the N 2 partial pressure. The corrosion behaviors of TiN films were investigated by potentiodynamic tests and electrochemical impedance spectroscopy (EIS) measurements under the condition of an aerated 1 M H 2SO 4 + 2 ppm HF solution at 70 °C with a constant potential of 600 mV SCE. The results revealed that the variation of N 2 pressure had an influence on the corrosion resistance of TiN coating. N 2 partial pressure of 0.4 mTorr showed good corrosion resistance with the lowest corrosion current density and the highest charge transfer resistance due to the low porosity.