Sandwich assembly of sulfonated poly (ether sulfone) with sulfonated multiwalled carbon nanotubes as an efficient architecture for enhanced electrolyte performance in <scp> H <sub>2</sub> </scp> / <scp> O <sub>2</sub> </scp> fuel cells
Gayathri Ravi Kumar, Guozhong Cao, M. Ramesh Prabhu
Abstract
Proton exchange membrane (PEM) for H2/O2 fuel cell are made as sandwich assembly of sulfonated poly(ether sulfone) (SPES) with sulfonic acid functionalized multiwalled carbon nanotubes (SMWCNT). The SMWCNT occupies at the middle layer enhances the interfacial interplay and interconnects the nano-phase separation via hydrogen bond between the sulfonic acid of SPES and SMWCNT. The sandwich structure improves the integration of hydrophilic and hydrophobic layers of SPES and SMWCNT, that obliviously enhance the tensile and mechanical property of the membrane. Thus promotes the continuous proton conducting channels through the sandwiched morphology by using the proton hopping mechanism. The 1.5 wt% of SMWCNT in SPES (G3) offers high proton conductivity, current and power density values at 80°C under 100% RH, which are 72.0 × 10−3 S cm−1, 778.26 mA cm−2 and 173.29 mW cm−2, respectively. Within addition to remarkable durability, the OCV degradation is about 0.02 V after 15 hours of durability test and H2 permeability of 2.14 barrer. The excellent thermal stability of 91.2 wt% at 150°C and the Young's modulus of 2208 ± 110 MPa was attained by the G3, which strongly suggest that the promising nature of PEM.