Tuning hydrophobic-hydrophilic balance of cathode catalyst layer to improve cell performance of proton exchange membrane fuel cell (PEMFC) by mixing polytetrafluoroethylene (PTFE)

A series of MEAs with hydrophobic cathode catalyst layer was successfully prepared using a spraying method by adding PTFE into the cathode catalyst layer ink. Our optimal MEA, MEA-PT50, its current density were recorded as 990 mA cm-2 at 0.7 V and 1400 mA cm-2 at 0.6 V, respectively; its maximum power density is up to 856 mW cm−2, which is much higher than that of the MEA without addition of PTFE (711 mW cm−2). Furthermore, our MEA-PT50 also exhibits excellent stability, and the current density only dropped from 1000 mA cm−2 to 90 0 mA cm−2 after a continuous operation of 60 h, for the MEA without addition of PTFE, it dropped from 1000 mA cm−2 to 770 mA cm−2 in the same duration and same conditions.265