Hybrid Aquivion® membranes doped by SiO2 and CsxH3-xPW12O40 with improved dimensional stability for proton exchange membrane fuel cells

Short-side-chain perfluorinated sulfonic acid membranes are promising polymer electrolytes for hydrogen-air fuel cells due to their high concentration of functional –SO 3 H groups. This study explores hybrid membranes based on low-equivalent-weight Aquivion® ionomer (EW = 790 g/mol) and inorganic dopants (SiO 2 and Cs x H 3 - x PW 12 O 40 ) to enhance performance. The modified membranes exhibit improved dimensional stability, water uptake and proton conductivity under both high and low humidity conditions. The conductivity of Aquivion + Cs x H 3 - x PW 12 O 40 is 4 times higher than that of the Aquivion. The maximum power density of the membrane electrode assembly with Aquivion + Cs x H 3-x PW 12 O 40 membrane (421 mW/cm 2 ) is 1.5 times higher compared to Aquivion at RH = 50 %. The results reveal the structure-properties-performance relationship of the hybrid Aquivion membranes and demonstrate the effectiveness of using hybrid membranes based on low-EW Aquivion polymer as an electrolyte in fuel cells operating at low humidity. • Silica and Heteropolyacid nanoparticles improve performance of Aquivion® PEMFC in low humidity conditions. • Transport performance in hybrid membranes is greater due to the nanoparticles participation. • Power of MEA with hybrid membrane is by 4–5 times higher as compared with Aquivion.