Electrochemical Characteristics with NaCl Concentrations on Stainless Steels of Metallic Bipolar Plates for PEMFCs

Shin, Dong-Ho; Kim, Seong-Jong

doi:10.3390/coatings13010109

Cited by 3 publications

(2 citation statements)

References 52 publications

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“…However, FCEVs use hydrogen gas as fuel, so various components are required [5,6]. Among them, the hydrogen valve performs the supplying and blocking functions of hydrogen gas, which is very important in the efficiency and safety of FCEVs [7,8].…”

Section: Introductionmentioning

confidence: 99%

Effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel for application to the hydrogen valves of hydrogen fuel cell electric vehicles

Shin,

Kim

2024

PLoS ONE

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Electroless nickel plating is a suitable technology for the hydrogen industry because electroless nickel can be mass-produced at a low cost. Investigating in a complex environment where hydrogen permeation and friction/wear work simultaneously is necessary to apply it to hydrogen valves for hydrogen fuel cell vehicles. In this research, the effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel (SUM 24L) were investigated. Due to the inherent characteristics of electroless nickel plating, the damage (cracks and delamination of grain) and micro-particles by hydrogen permeation were clearly observed at the grain boundaries and triple junctions. In particular, the cracks grew from grain boundary toward the intergranualr. This is because the grain boundaries and triple junctions are hydrogen permeation pathways and increasing area of the hydrogen partial pressure. As a result, its surface roughness increased by a maximum of two times, and its hardness and adhesion strength decreased by hydrogen permeation. In particular, hydrogen permeation increased the friction coefficient of the electroless nickel-plated layer, and the damage caused by adhesive wear was significantly greater, increasing the wear depth by up to 5.7 times. This is believed to be due to the decreasing in wear resistance of the electroless nickel plating layer damaged by hydrogen permeation. Nevertheless, the Vickers hardness and the friction coefficient of the electroless nickel plating layer were improved by about 3 and 5.6 times, respectively, compared with those of the free-cutting steel. In particular, the electroless nickel-plated specimens with hydrogen embrittlement exhibited significantly better mechanical characteristics and wear resistance than the free-cutting steel.

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Section: Introductionmentioning

confidence: 99%

Effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel for application to the hydrogen valves of hydrogen fuel cell electric vehicles

Shin,

Kim

2024

PLoS ONE

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“…Many materials are being developed as bipolar plates in PEMFCs. Stainless steel, which is used in metallic bipolar plates, is generally known to have excellent corrosion resistance, which is achieved by forming oxide films [20].…”

Section: Introductionmentioning

confidence: 99%

Review of materials, functional components, fabrication technologies and assembling characteristics for polymer electrolyte membrane fuel cells (PEMFCs) – An update

DAYA,

SAMSON NESARAJ

2023

J Met Mater Miner

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Fuel cells use electrochemical processes to transform the chemical energy of a fuel into electrical energy, which is a key enabler for the shift to an H2-based economy. Because of their high energy conversion efficiency and low pollution emissions, fuel cells with polymer electrolyte membranes (PEMFCs) are regarded as being in frontline of commercialization for the transportation and automotive industries. However, there are two major hurdles to their future commercialization: cost and durability, which promote basic study and development of their components. In this article, we reviewed the materials, functional components, fabrication technologies and assembling characteristics related to PEMFCs. Platinum's significance as a catalyst in PEMFC applications stems from the fact that it beats all other catalysts in three critical parts: stability, selectivity, and activity. In order to create Pt rich surfaces of NPs, Pt metal is alloyed with d-block metals like Cu, Ni, Fe, and Co. PEMFC development is inextricably tied to the benefits and drawbacks of the Nafion membrane under various operating circumstances. Nafion membrane has some drawbacks, including poor performance at high temperatures (over 90℃), low conductivity under low humidification, and high cost. As a result, a variety of nanoscale additives are frequently added to Nafion nanocomposites to enhance the material's properties under fuel cell working conditions. Fiber composite based bipolar plates can deliver best performance. The assembly of PEMFC based on strap approach is being explored. The applications of PEMFC are also projected.

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Electrochemical characteristics and damage mechanism in scrubber washing water of UNS N08367 with plasma ion nitriding and electropolishing

Hwang,

Kim

2024

npj Mater Degrad

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In this investigation, electropolishing and plasma ion nitriding are applied to super austenitic stainless steel for the purpose of improving its corrosion and pitting resistance. Electrochemical experiments are conducted with washing water collected directly from the ship’s scrubber. After electropolishing, the surface roughness is improved by about 73.6% compared to mechanical polishing. After plasma ion nitriding, CrN (precipitate), Fe4N (compound), and γN (solid solution) are observed on the surface. The thickness of the layer formed on the surface is measured to be about 10 μm. A hysteresis loop is observed in the cyclic potentiodynamic polarization curves of mechanical polishing and electropolishing, and the areas are calculated as 23.33 mW cm−2 and 0.17 mW cm−2, respectively. The polarization curve of plasma ion nitriding presents perfect passivation characteristics. Accordingly, mechanical polishing and electropolishing reveal local corrosion, whereas plasma ion nitriding presents a tendency towards general corrosion. In the mechanical polishing, electropolishing, and plasma ion nitriding, the corrosion current densities are 0.665 μA cm−2, 0.093 μA cm−2, and 16.47 μA cm−2, respectively, and the maximum damage depth is observed to grow progressively smaller from plasma ion nitriding to electropolishing and then mechanical polishing.

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Electrochemical Characteristics with NaCl Concentrations on Stainless Steels of Metallic Bipolar Plates for PEMFCs

Cited by 3 publications

References 52 publications

Effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel for application to the hydrogen valves of hydrogen fuel cell electric vehicles

Effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel for application to the hydrogen valves of hydrogen fuel cell electric vehicles

Review of materials, functional components, fabrication technologies and assembling characteristics for polymer electrolyte membrane fuel cells (PEMFCs) – An update

Electrochemical characteristics and damage mechanism in scrubber washing water of UNS N08367 with plasma ion nitriding and electropolishing

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