Preparation of Fluorine Doped Zinc Tin Oxide Coating Layer on SUS 316 Bipolar Plates by ECR-MOCVD for PEMFC

Abstract

Fluorine-doped zinc tin oxide (ZnSnOx:F) films on SUS316 are prepared by electron cyclotron resonance-metal organic chemical vapor deposition (ECR-MOCVD) in order to achieve the corrosion-resistant and low contact resistance bipolar plates for polymer electrolyte membrane (PEM) fuel cells. The prepared ZnSnOx:F films coated on SUS316 substrate are characterized by X-ray diffraction (XRD), auger electron microscopy (AES) and field emission-scanning electron microscopy (FE-SEM). To simulate the aggressive PEMFC environment, all of the electrochemical experiments are conducted in 1M H2SO4 + 2ppm HF solution at 70 degrees C. The fluorine doping appears to be one of the critical process parameters on the formation of the corrosion-protective layer for PEMFC bipolar plates, as well as affecting the electrical properties of the films.