Accelerated corrosion and electrochemical characteristics of carbon-coated titanium bipolar plates by doctor-blade technology for PEMFC

• Published in: Npj Materials degradation Vol. 9; no. 1; pp. 105 - 16
• Main Authors: Hwang, Hyun-Kyu, Kim, Seong-Jong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.08.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166; 639/301; Anatase; Carbon; Chemical vapor deposition; Chemistry and Materials Science; Coatings; Commercialization; Contact resistance; Corrosion and Coatings; Corrosion resistance; Electric contacts; Electric double layer; Electrical resistivity; Electrochemical analysis; Electrochemistry; Fuel cells; Graphene; Interfaces; Manufacturers; Materials Science; Nanocrystals; Plates; Spectrum analysis; Stainless steel; Structural Materials; Titanium; Titanium dioxide; Tribology; United States > US
• ISSN: 2397-2106; 2397-2106
• DOI: 10.1038/s41529-025-00651-1

In this investigation, a carbon layer was coated onto a TiO 2 surface using a roll-to-roll doctor blade method to enhance the electrochemical performance of titanium bipolar plates for PEMFCs. XRD analysis confirmed the formation of anatase-phase TiO₂. And cross-sectional SEM–EDS analysis verified the presence of the carbon layer. In ex-situ accelerated corrosion experiments simulating PEMFC environments, Ti with TiO 2 +carbon coatings presented higher current density than bare Ti. This is interpreted as being due to the capacitive charge/discharge behavior of the electric double layer formed by the carbon layer. But, the coated specimen met the U.S. DOE corrosion resistance criterion (i corr  < 1 μA/cm 2 ). Especially, bare Ti failed to meet the interfacial contact resistance (ICR) standard both before and after testing. In contrast, the TiO₂+carbon-coated specimen maintained ICR values below 10 mΩ·cm 2 at 140 N/cm 2 . In addition, SEM analysis after all electrochemical experiments confirmed that the coating remained free of delamination or damage. In particular, cyclic voltammetry experiment results further confirmed stable capacitive behavior even after 300 cycles. These findings indicate that doctor blade-based TiO 2 +carbon coatings are effective in enhancing both corrosion resistance and electrical conductivity. This suggests that the proposed process is a viable alternative to conventional PVD or CVD methods for commercialization.