Corrosion Protection of 304 Stainless Steel Bipolar Plates of PEMFC by Coating SnO2 Film

• Published in: International journal of electrochemical science 2017-11, Vol.12 (11), p.10946-10957
• Main Authors: Yang, Linghui, Qin, Zhenlan, Pan, Hongtao, Yun, Hong, Min, Yulin, Xu, Qunjie
• Format: Article
• Language: English
• Subjects: 304 stainless steel; bipolar plate; corrosion; Proton exchange membrane fuel cell (PEMFC); tin oxide (SnO2) film
• ISSN: 1452-3981; 1452-3981
• DOI: 10.20964/2017.11.67

Tin oxide (SnO2) film was successfully coated on surface of austenite 304 stainless steels (304SS) by combining sol-gel dip-coating method with alcohol thermal method. The coated SnO2 film was used to enhance corrosion resistance of 304SS bipolar plates in a simulated proton exchange membrane fuel cell (PEMFC) environment. Bared 304SS and SnO2 coated 304SS were investigated via EIS, potentiodynamic polarization curves and potentiostatic polarization curves measurements in a simulated PEMFC cathodic, anodic environment, respectively. Compared with the bared 304SS, the corrosion current density for the SnO2 coated 304SS was decreased significantly from 33.22 μA/cm2 to 0.1327 μA/cm2 in a simulated cathodic environment, and from 75.079 μA/cm2 to 0.1581 μA/cm2 in a simulated anodic environment. Surface structure and chemical composition of the samples were obtained by SEM, EDX, AFM, XRD and XPS. The result showed that a uniform and compact SnO2 film was coated on the surface of 304SS, which enhanced the corrosion resistance of 304SS in a simulated PEMFC environment.