Characterisation of PAMPS–PSS pore-filling membrane for direct methanol fuel cell

• PAMPS–PSS pore-filling membranes were fabricated and characterised.
• PAMPS–PSS membranes show equivalent proton conductivity as Nafion.
• PSS-80 shows 27 times lower methanol permeability than Nafion.
• DMFC performance increased twice by tuning the PSS content ration.

A novel, low cost polymer electrolyte membrane for direct methanol fuel cell (DMFC) has been fabricated using the pore-filling technique with copolymer composed of poly-2-acrylamide-2-methylpropanesulphonic acid (PAMPS) and poly-styrene sulphonic acid (PSS) impregnated in a porous polyimide (PI) substrate. The pore-filling membranes, as well as a Nafion membrane as a reference, were subjected to proton conductivity, methanol permeability and DMFC performance tests at various methanol concentrations to understand the effect of ion-conductive copolymer component towards the DMFC applications. PAMPS–PSS pore-filling membranes showed a decrease in methanol permeability whilst they retained their proton conductivity, consequently improving the DMFC performance compared to commercial Nafion membrane. The steric and hydrophobic properties of PSS allow to improve methanol crossover, achieving high DMFC performance in methanol concentration up to 5 mol L−1, demonstrating that PAMPS–PSS pore-filling membranes are attractive for the DMFC applications.