Composite membranes of Nafion and poly(styrene sulfonic acid)-grafted poly(vinylidene fluoride) electrospun nanofiber mats for fuel cells

• Published in: Journal of membrane science Vol. 466; pp. 238 - 245
• Main Authors: Li, Hsieh-Yu, Lee, Yun-Yang, Lai, Juin-Yih, Liu, Ying-Ling
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2014; Elsevier
• Subjects: Applied sciences; Chemistry; Colloidal state and disperse state; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrospinning; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; Fuel cell; Fuel cells; General and physical chemistry; Maximum power density; Membranes; Methyl alcohol; Nafion; Nanofiber; Nanostructure; Polymer industry, paints, wood; Polystyrene resins; Proton exchange membrane; Reinforcement; Technology of polymers; Nanofiber; Proton exchange membrane; Nafion; Fuel cell; Sulfonate polymer; Polymeric membrane; Fluorine containing polymer; Proton exchange; Composite material
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2014.04.057

Surface-initiated atom transfer radical polymerization has been performed on poly(vinylidene fluoride) electrospun nanofibers (PVDFNF) to incorporate poly(styrenesulfonic acid) (PSSA) chains tethered on PVDFNF surfaces. The obtained PSSA-g-PVDFNF nanofibers are used as reinforcement for Nafion to prepare Nafion/PSSA-g-PVDFNF composite membrane (Nafion/NF-CM). The PSSA chains tethered on the nanofiber surfaces improve the interfacial compatibility between the nanofiber reinforcement and the Nafion matrix, and might provide a proton-conducting pathway along the nanofibers. As a result, the proton conductivity of Nafion/NF-CM membrane is 2.5-fold of the value recorded with the nanofiber-free recasting Nafion membrane. The H2/O2 single cell employing Nafion/NF-CM membrane shows a maximum power density of 770mWcm−2 which is 1.5-fold of the value recorded with the commercial Nafion 212 membrane and a current density at 0.6V of 940mAcm−2 which is about 2.7-fold of the value recorded with Nafion 212. The Nafion/NF-CM membrane is also suitable for direct methanol fuel cell, in which it could be operated at a 5M methanol solution to show a cell performance of 91.2mWcm−2 for maximum power density and 464mAcm−2 for current density at 0.2V, which are about 1.5-fold of the values recorded with the commercial Nafion 117 membrane at 2M methanol solution. [Display omitted] •Surface-initiated ATRP has been performed from PVDF nanofibers.•Polyelectrolyte-grafted PVDF nanofibers form proton-conducting pathways in Nafion.•The composite membrane shows high proton conductivity and low methanol permeability.•Compared to Nafion 212, a 1.5-fold cell performance has been recorded.