Novel Composite Membranes Based on Polyaniline/Ionic Liquids for PEM Fuel Cells Applications

Abstract

The modern development of (PEMFCs) is still faced by several obstacles such as membrane cost and performance. Perfluorosulfonic acid membranes (e.g. Nafion of DuPont) are currently the most successful in PEMFCs. PEMFCs usually operate at temperatures around 80°C and at atmospheric pressure. Higher temperature operation (T >100°C) is preferred and has several advantages including enhanced fuel cell kinetics, improved catalysts tolerance for contaminants and recovery of useful heat. However, the high-temperature operation is not permitted using Nafion membranes as they dehydrate and their proton conductivity dramatically decreases, thus, lowering the fuel cell efficiency. Therefore, this work aims at developing a Nafion-free membrane that would successfully operate at higher temperatures and with reasonable proton conductivity (preferably higher than 10-3 S/cm). In this study, novel solid proton conductors based on polyaniline (PANI) and ionic liquids (ILs) are proposed as membranes in PEMFCs. PANI-IL composite membranes are fabricated using porous polytetrafluoroethylene (PTFE) as support. The composite membrane was evaluated for its proton conductivity. The results showed a high proton conductivity range of 0.01 to 0.02 S/cm when a 3.7 wt % of the ionic liquid (IL)[1-Hexyl-3-Methylimidazolium Tricyanomethanide] was used.

A Critical Review on the Use of Ionic Liquids in Proton Exchange Membrane Fuel Cells

“…For instance, the highest conductivity and fuel-cell performance recorded were 55 mS/cm and 168.9 mW/cm 2 at 80 • C, respectively. Eisa et al [143] prepared PEMFC based on polyaniline (PANI), 1-Hexyl-3-Methylimidazolium Tricyanomethanide IL, and ZrP. The proposed PEMFC with (50:50 mg) PANI/ZrP and 3.7 wt.% IL showed a promising ionic conductivity of 20 mS/cm at room temperature.…”

The Operating Parameters, Structural Composition, and Fuel Sustainability Aspects of PEM Fuel Cells: A Mini Review

“…However, it suffers from drawbacks, especially fuel crossover. Hence, researchers developed modified types of membranes, such as modified perfluorinated composite membranes, inorganic nanocomposite membranes, hydrocarbon polymers membranes, fullerene-based membranes [34], polystyrene-sulfonic acid membranes, sulfonated polyimide-based membranes, and polybenzimidazole based membranes [69,[74][75][76][77].…”