Long-term polarization accelerated degradation of nano-thin C/Ti coated SS316L bipolar plates used in polymer electrolyte membrane fuel cells. (15th February 2022)

• Record Type: Journal Article
• Authors: Wang, Xian-Zong; Zhang, Meng-Meng; Shi, Dong-Dong; Zhang, Shang-Chen; Wu, Yuan-Min; Gong, Wei-Jia; Fan, Hong-Qiang
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 14(2022)
• Page Start: 8974
• Page End: 8992
• Publication Date: 2022-02-15
• Subjects: Nano-thin C/ti coating -- High transient potential -- Potential fluctuation -- Interfacial contact resistance -- Metal bipolar plates -- Polymer electrolyte membrane fuel cells; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.12.229
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Dynamic potentials of polymer electrolyte membrane fuel cells (PEMFCs) lead to the corrosion of metal bipolar plates and significantly increase their interfacial contact resistance (ICR). Herein, two nano-thin C/Ti coatings with different thicknesses are prepared on SS316L (C/Ti/SS) and examined under three types of polarization potential modes. The C100 Ti60 coating has improved corrosion resistance than C20 Ti140 coating. The C100 Ti60 coating exhibits a low ICR of 2.67 mΩ cm 2 and a small corrosion rate of 1.47 μA/cm 2, highlighting the high electrical conductivity and corrosion resistance. Moreover, C100 Ti60 /SS achieves a slight degradation of ICR after polarization at 0.67 V and cyclic polarization between 0.43 and 0.73 V. However, the high potential of 1.43 V induces severe delamination of C layer, resulting in a remarkable increase of ICR. Analysis suggests that the Ti layer improves the oxidation resistance and the C layer could provide effective protection when the potential is below 1.13 V. Graphical abstract: Image 1 Highlights: Two nano-thin C/Ti coatings with different thicknesses are prepared on SS316L. Highly corrosion resistant and electrical conductive C100 Ti60 /SS is achieved. Evolution of ICRs of C100 Ti60 /SS under three polarization modes are studied. Anodic dissolution processes of C100 Ti60 /SS at different potentials are analyzed. Correlation between ICR and negative current during cyclic polarization is discussed.