Self-humidifying membrane electrode assembly prepared by adding PVA as hygroscopic agent in anode catalyst layer

In this work, a novel self-humidifying membrane electrode assembly (MEA) with addition of polyvinyl alcohol (PVA) as the hygroscopic agent into anode catalyst layer was developed for proton exchange membrane fuel cell (PEMFC). The MEA shows good self humidification performance, for the sample with PVA addition of 5 wt.% (MEA PVA5), the maximum power density can reach up to 623.3 mW·cm−2, with current densities of 1000 mA·cm−2 at 0.6 V and 600 mA·cm−2 at 0.7 V respectively, at 50 °C and 34% of relative humidity (RH). It is interesting that the performance of MEA PVA5 hardly changes even if the relative humidity of both the anode and cathode decreased from 100% to 34%. The MEA PVA5 also shows good stability at low humidity operating conditions: keeping the MEA discharged at constant voltage of 0.6 V for 60 h at 34% of RH, the attenuation of the current density is less than 10%, whilst for the MEA without addition of PVA, the attenuation is high up to 80% within 5 h.

► A self-humidifying MEA is firstly prepared by adding PVA in anode catalyst layer. ► The MEA still shows excellent performance even if the RHs are lower down to 34%. ► Good self-humidification stability is confirmed by a 60 h long term experiment.