Investigation on composite S-PEEK/H-BETA MEAs for medium temperature PEFC

The introduction of different percentages of H-BETA zeolite, as an inorganic filler, into the S-polyetheretherketone (S-PEEK) membrane was investigated. For the good thermal stability, a sulphonation degree of about 50% was chosen for the bare S-PEEK. The obtained membranes were studied in terms of chemical–physical and electrochemical properties. The introduction of zeolite produces a strong reduction of the swelling with respect to the bare S-PEEK membrane without decreasing the proton conductivity. The benefit of the zeolite introduction is confirmed by the electrochemical tests, reaching higher performance than bare S-PEEK membrane at temperature over 100 °C.Composite electrodes with different percentages of zeolite in the catalytic layer were developed to improve the water management at T>100∘C. A composite MEA, obtained by assembling the best composite membrane and electrodes, was produced and characterised in terms of I–V   curve at 120∘C reaching a maximum power density of about 310mWcm-2.