scholarly journals Improvement of Corrosion Resistance and Electrical Conductivity of Stainless Steel 316L Bipolar Plate by Pickling and Passivation

2021 ◽  
Vol 12 (3) ◽  
pp. 101
Author(s):  
Yu Leng ◽  
Daijun Yang ◽  
Pingwen Ming ◽  
Bing Li ◽  
Cunman Zhang

Corrosion resistance and electrical conductivity of stainless steel bipolar plate remains a big challenge while it has been regarded as the most promising candidate for proton exchange membrane fuel cell. The purpose of this paper is to study the effects of pickling and passivation by sulfuric acid and a mixture of nitric and fluoric acids, respectively, on corrosion resistance and electrical conductivity of stainless steel 316L (SS316L) bipolar plate. First, pickling of the specimens of SS316L is performed in a 15 wt.% H2SO4. Afterwards, the specimens are passivated in a mixture of 12 wt.% HF and 4 wt.% HNO3. Electrochemical and interfacial conductivity tests are conducted to examine the change in corrosion resistance and electrical conductivity of SS316L. Finally, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) reveal the evolution of surface morphology, chemical composition and surface conductivity. The results show that the corrosion resistance and electrical conductivity of SS316L could be improved significantly by pickling and passivation. The increase in Cr:Fe ratio as well as a more uniform surface with higher conductivity is the main reason for the improvement of corrosion resistance and interfacial conductivity of SS316L.

RSC Advances ◽  
2016 ◽  
Vol 6 (37) ◽  
pp. 31367-31373 ◽  
Author(s):  
Jinlong Cui ◽  
Zhendong Yao ◽  
Fupeng Cheng ◽  
Yongfu Cui ◽  
Guanqin Wang ◽  
...  

A W-modified layer is prepared on 430 SS via plasma surface diffusion alloying to improve its corrosion resistance in marine PEMFCs.


2014 ◽  
Vol 905 ◽  
pp. 167-170 ◽  
Author(s):  
Yeon Jae Kim ◽  
Dong Hyun Kim ◽  
Jung Soo Kim ◽  
Jae Ho Jang ◽  
Uoo Chang Jung ◽  
...  

Chemical converted graphene (CCG) were coated on 316L stainless steel as a bipolar plate which is a component of proton exchange membrane fuel cell (PEMFC) by electro spray coating (ESC). Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to examine the thickness and surface properties of coating layer. Electrochemical potentiodynamic test was conducted in acidic atmosphere (0.1N H2SO4+2ppm F-) at 80°C using Versastat 4 and analysis program for corrosion resistance measurement. After packing bipolar plates for PEMFC stack, the electrical performances of graphite, bare SS316L and graphene coated SS316L bipolar plates were evaluated by PEMFC evaluating device. The chemical converted graphene was founded on the surface of coated SS316L, and the thickness was 12μm. Graphene coated bipolar plate showed high corrosion resistance of 1.32×10-7A/cm2beside bare SS316L bipolar plate. In electrical performance evaluation, the graphene coated bipolar plate was shown 0.978V on Voc and 0.5A/m2on the reduction potential (0.6V). Although the electrical performance of the graphene coated bipolar plate is lower than graphite bipolar plate, the thickness and weight is lower than graphite bipolar plate. These advantages can enable the PEMFC system more efficiently and economically.


Fuel Cells ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 724-730 ◽  
Author(s):  
T. Li ◽  
P. C. Zhang ◽  
K. Liu ◽  
S. Xu ◽  
Y. T. Han ◽  
...  

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