Electrochemical Properties of Niobium Modified AISI316L Stainless Steel Bipolar Plates for Direct Formic Acid Fuel Cell

Abstract

To ameliorate the corrosion resistance and surface electrical conductivity of AISI316L stainless steel (316L SS) as bipolar plates for direct formic acid fuel cell (DFAFC), a niobium diffusion layer has been successfully prepared on 316L SS substrate via the plasma surface diffusion alloying (PSDA) technique. The niobium modified AISI316L stainless steel (Nb‐316L SS) has a compact and successive niobium diffusion layer with a lower interfacial contact resistance (ICR) compared with bare 316L SS. The electrochemical behaviors of Nb‐316L SS in simulated varied anode (0.05M H2SO4 + 2 ppm HF + xM formic acid (x = 2, 5, 10 and 15) solution at 50 °C) and cathode (0.05M H2SO4 + 2 ppm HF solution at 50 °C, bubbled with air) DFAFC environments are systematically studied. The results show that the corrosion resistance of 316L SS is distinctly bettered in both anode and cathode environments of DFAFC after the PSDA modification. After 4 h potentiostatic polarization tests, the ICR of bare and Nb‐316L SS have increased at the clamping force of 140 N cm−2, but the increasing amplitude of the ICR for Nb‐316L SS is much smaller than that of bare 316L SS.

Niobium- and titanium-based coating for the protection of carbon steel SAE 1020 against corrosion

“…The reduction in the value of n for the coated sample suggests a coating with a rough, heterogenous surface, in contrast to the smoother, more homogenous surface of the bare material, evidenced by a higher value of n. These results can be verified by the micrographs seen in Figures 1 and 2 (Mofidabadi et al , 2021). The values obtained for the R sol were similar in magnitude for the coated and uncoated material, showing that the electrolytes used in both analyses did not vary significantly, presenting similar conductivity (Cui et al , 2017b). R ct results showed a great difference in value between the samples.…”

High Oxidation Resistance of CVD Graphene-Reinforced Copper Matrix Composites

“…A sample 12.6 mm in diameter and 1.9 mm in thickness was set between two polished copper blocks (indenters) and the total electrical resistance was recorded. Considering that the intrinsic electrical resistivity of our sample, indenters, and electrical leads are small, the measured total electrical resistance came mostly from the ICR, which is as a function of the applied clamping pressure [33]. In Figure 4b, it can be seen that the ICR of the samples initially decreased and then reached a constant value with an increase of the applied clamping pressure.…”

Theoretical Screening of Transition Metal Alloys with High Corrosion Resistance: The Case of Ta-Based Alloys as an Example

“…9,10 Therefore, anticorrosive coatings have been widely explored to enhance the corrosion resistance of BPs. 11−15 Commonly, noble metals and their alloys exhibit high corrosion resistance and high conductivity and are usually coated on BPs, 11,16 however, the high price prohibits the large-scale application. Therefore, non-noble transition metals with high corrosion resistance, such as Nb, Ta, Cr, and Ti, are the new candidates.…”

“…Hydrogen energy has been demanded and consumed ever-growing, which promotes the development of hydrogen-source technologies. − Proton exchange membrane water electrolysis (PEMWE) was focused, which could produce high-pressure and high-purity hydrogen. − Bipolar plates (BPs) as important components of PEMWE should possess low weight and high corrosion resistance. , Therefore, anticorrosive coatings have been widely explored to enhance the corrosion resistance of BPs. − Commonly, noble metals and their alloys exhibit high corrosion resistance and high conductivity and are usually coated on BPs, , however, the high price prohibits the large-scale application. Therefore, non-noble transition metals with high corrosion resistance, such as Nb, Ta, Cr, and Ti, are the new candidates.…”