Barrier properties of sulfonated polysulfone/layered double hydroxides nanocomposite membrane for direct methanol fuel cell operating at high methanol concentrations

• Published in: International journal of hydrogen energy Vol. 45; no. 40; pp. 20647 - 20658
• Main Authors: Lufrano, E., Simari, C., Lo Vecchio, C., Aricò, A.S., Baglio, V., Nicotera, I.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 14.08.2020
• Subjects: DMFC; LDH; Nanocomposite membrane; PFG-NMR; Sulfonated polysulfone; LDH; Sulfonated polysulfone; PFG-NMR; Nanocomposite membrane; DMFC
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2020.02.101

High performing and cost effective nanocomposite membranes for DMFC application are synthesized by incorporating hygroscopic layered double hydroxides (LDH) particles into sulfonated polysulfone (sPSU). A significant improvement in the dimensional stability as well as in the water and methanol molecular dynamics of the sPSU_LDH composite membrane is observed in comparison with both pristine sPSU and Nafion 212. The strong electrostatic interaction occurring between positively charged LDH platelets and negatively charged polymer chains of sPSU alters the microstructure of the ionic domains, allowing an effective reduction of the methanol permeability whilst improving the proton conductivity. The methanol crossover measurements confirmed that sPSU_LDH membranes are able to withstand high methanol concentration without significant aftermath on the chemical stability of the electrolyte. The features enable the single DMFC assembled with the sPSU_LDH nanocomposite to achieve the remarkable power density of 150 mW cm−2 at 80 °C in 5 M methanol solution. [Display omitted] •Layered Doubled Hydroxide (LDH) were evaluated as nanofiller in sPSU-based composites.•Composite membranes revealed remarkable dimensional stability at high methanol concentration.•Water and methanol dynamics in the samples investigated by NMR spectroscopy (PFG and T1).•LDH platelets act as physical crosslinker reducing methanol crossover.•Single DMFC with sPSU_LDH membranes exhibits maximum power density of 150 mW cm−2.