Nature-inspired hybrid wettability surface to enhance water management on bipolar plates of PEMFC

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 466; p. 143288
• Main Authors: Zhao, Taotao, Jiang, Ke, Fan, Wenxuan, Lu, Dafeng, Zheng, Deli, Cui, Hao, Yang, Luobin, Lu, Guolong, Liu, Zhenning
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2023
• Subjects: Bipolar plates; Hybrid wettability; Nature-inspired surface; Proton exchange membrane fuel cell (PEMFC); Water management; Water management; Proton exchange membrane fuel cell (PEMFC); Nature-inspired surface; Hybrid wettability; Bipolar plates
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.143288

[Display omitted] •A nature-inspired superhydrophobic-superhydrophilic hybrid surface was fabricated.•The hybrid surface can capture, store and drain water droplet at high efficiency.•The effect of superhydrophilic groove width on various functions has been studied.•The hybrid wettability surface improves water management on bipolar plates.•The cell performance of single PEMFC with the hybrid surface is enhanced by 26.3%. Proton exchange membrane fuel cell (PEMFC) requires both sufficient water in proton exchange membrane (PEM) and fast water drainage in flow channel to achieve a desirable performance, which creates a dilemma for water management. Herein, we have fabricated a nature-inspired bionic multifunctional surface (BMS) consisting of superhydrophobic coating and superhydrophilic groove. The characterizations of water contact angle, morphology and chemical composition have verified the successful preparation of hybrid wettability surface. The effects of groove width on droplet capture, storage and drainage have been investigated, which yields an optimal width of 600 μm. More importantly, BMS has been fabricated inside the flow channel of graphite bipolar plate (BMS@BP). The peak power density of BMS@BP cell is 26.3% higher than that of the cell without BMS. Under a drought-inclined condition of low current and humidity, BMS@BP mitigates the increase of internal resistance caused by PEM dry-out, whereas under a condition prone to flooding (high current and humidity), BMS@BP can reduce the voltage fluctuation and pressure drop variation incurred by flooding. Hence, BMS has demonstrated a capacity to balance the opposite needs of moisturizing PEM and draining channel water. Our work may afford an innovative hybrid-wettability-based approach to enhance water management for PEMFC.