Superhydrophobic Stainless Steel Bipolar Plates with Fractal Structure for Fuel Cells by Nanosecond Laser Ablation. Issue 12 (2nd August 2022)

• Record Type: Journal Article
• Authors: Yang, Gang; Zhang, Dongguang; Wu, Yali; Xue, Xiaoting; Liang, Chenyu; Yang, Jiayi; Xing, Ruizhe
• Is Part Of: Advanced engineering materials. Volume 24:Issue 12(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-02
• Subjects: antifrosting -- anti-icing -- bipolar plates -- fractal structure -- nanosecond laser ablation -- superhydrophobicity; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.202200706
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Bipolar plate (BP) is one of the crucial components in proton exchange membrane fuel cells (PEMFCs). In extreme cold weather, massive vapor condensation happens right at vehicle start‐ups, which likely causes "water flooding" and thus shortens the lifespan of PEMFCs. Herein, a superhydrophobic stainless steel bipolar plate (SH‐SS BP) that is fabricated by nanosecond laser ablation is reported. Through a repeated low‐energy processing strategy, fractal surface microstructure is fabricated, which has not been reported for SS BP. By grafting stearic acid (SA) monolayer, a robust SH‐SS BP is obtained with a contact angle of 151.74°. The fractal microstructure greatly enhances the contact area between SH‐SS BP and membrane electrode assembly (MEA), which improves interfacial contact resistance (ICR: 9.816 mΩ cm 2 at 1.5 MPa). The SH‐SS BP shows significantly enhanced anticorrosion performance ( I c o r r = 8 .191×10 ‐8 A cm −2 ) by effectively reducing penetration of corrosive. The ability of improving water management in PEMFC under extreme cold condition is further demonstrated in a simulated PEMFC. This study opens new opportunity to reinforce metallic BPs by a simple, low‐cost, and robust route, which is valuable in improving comprehensive weather fastness of PEMFC. Abstract : Superhydrophobic 316L stainless steel bipolar plate is fabricated by a repeated low energy nanosecond laser ablation. This unique processing route provides the samples with multiple times of thermal quenching, which leads the surface to be fractal and contains more martensite phases. This is ideal for improving the water management of proton exchange membrane fuel cells (PEMFCs) during extreme cold scenario.