Impact of Mesoporous and Microporous Materials on Performance of Nafion and SPEEK Polymer Electrolytes: A Comparative Study in DEFCs

Abstract

Hybrid membranes are prepared from fluoro and non‐fluoro polymer membrane matrices with mesoporous and microporous inorganic materials. Nafion‐Si‐MSU‐F, Nafion‐Al‐MCM‐41, and zeolite 4A‐SPEEK‐MSA hybrid membranes are fabricated by solution casting method. The structural properties of the membranes are characterized using FE‐SEM and AFM techniques. Ion exchange capacity, sorption, proton conductivity, and thermal stability for the membranes have been extensively investigated. Ethanol permeability measurements for the membranes are performed using electrochemical as well as diffusion cell method. Among the membranes that are tested in direct ethanol fuel cells (DEFCs), Nafion‐Al‐MCM‐41 hybrid membrane delivered the highest peak power‐density of 44 mW cm–2 at 70 °C.

SPEEK/Zeolite/Ionic‐Liquid Anhydrous Polymer Membranes for Fuel‐Cell Applications

“…All of these morphological changes may be associated with phase rearrangement of hydrophilic and hydrophobic regions in the SPEEK microstructure during the formation of homogeneous SPEEK/zeolite/IL composite membranes. [42] The thermal stability of pristine SPEEK and the composite membranes was investigated by TG measurements. Figure 4 shows the thermal stability of the neat SPEEK membrane and the composite membranes with the C4MI (A) or C10MI (B) ionic liquids.…”

“…The same behavior was observed for C10MI samples; that is, the average roughness decreases from (1.97 ± 0.12) to (1.37 ± 0.11) nm and then increases again to (1.52 ± 0.13) nm. All of these morphological changes may be associated with phase rearrangement of hydrophilic and hydrophobic regions in the SPEEK microstructure during the formation of homogeneous SPEEK/zeolite/IL composite membranes …”