| Abstract Scope |
Titanium is considered a promising material for bipolar plates in proton exchange membrane fuel cells owing to its excellent corrosion resistance and low weight. However, its high interfacial contact resistance(ICR) and poor surface hydrophilicity hinder practical applications. This study presents a combined approach using carbon coating and femtosecond laser surface treatment to enhance both electrical conductivity and hydrophilicity of titanium sheets. Femtosecond laser texturing under various power densities and scanning speeds produced controlled micro/nano-scale surface structures. The process induced localized breakdown of the native oxide layer and increased the effective contact area, leading to reduced ICR. Additionally, hierarchical surface structures and modified surface chemistry significantly improved hydrophilicity. Under optimized conditions, the contact angle decreased by 20°, and the ICR was reduced by approximately 30% compared with untreated titanium. These results demonstrate that femtosecond laser processing coupled with carbon coating provides an eco-friendly and scalable surface engineering strategy for PEMFC applications. |