Composite Sulfonated Polyether Ether Ketone (SPEEK) Membranes with 3-(Trihydroxysilyl)-l-Propanesulfonic Acid for a Direct Methanol Fuel Cell (DMFC)

摘要

3-(trihydroxysilyl)-l-propanesulfonic acid (TPS) was used as a precursor to prepare SPEEK composite membranes (with added sulfonated silica). The ionic conductivity of SPEEK composite membranes (at 60°C in DI water) increased ~15mS/cm after incorporation of 15wt% TPS, and the methanol permeability was slightly reduced (5-10%). Two batches of SPEEK with different ion exchange capacity (IEC) were prepared. SPEEK 11 and SPEEK 13 have IEC of 1.06±0.02mmolg~(-1) and 1.34±0.05mmolg~(-1),respectively. SPEEK 1 1+5wt% TPS and SPEEK13+5wt% TPS composite membranes were tested in a DMFC at 60°C using air and 3M methanol, and the current density obtained at 0.4V was 187 mA/cm2 and 240mA/cm2 respectively.