Short-side-chain composite membranes with polyaminobenzene sulfonic acid-enriched single-walled carbon nanotubes for polymer electrolyte fuel cells

This study reports the fabrication of composite membranes based on short-side-chain perfluorosulfonic acid (SSC-PFSA) polymers reinforced with polyaminobenzene sulfonic acid-functionalized single-walled carbon nanotubes (PABS-f-SWCNTs) for enhanced polymer electrolyte membrane fuel cell (PEMFC) performance. The dual-functionalized SWCNTs, enriched with –SO₃H and –NH₂ groups, were uniformly dispersed within the SSC-PFSA matrix, promoting dipolar interactions and efficient proton conduction pathways. Comprehensive characterization confirmed improved ion exchange capacity, water uptake, thermal stability, and proton conductivity, with the 0.5 wt% PABS-f-SWCNT composite membrane exhibiting optimal performance. Under fuel cell operating conditions, this membrane demonstrated a peak power density of 1707 mW cm⁻² at 100% RH and sustained high current density at reduced humidity, outperforming the pristine SSC-PFSA membrane. The findings highlight the synergistic role of zwitterionic functional groups and nanotube reinforcement in advancing next-generation PEMFC membrane technology.