Enhanced low-humidity performance of proton-exchange membrane fuel cell by introducing hydrophilic CNTs in membrane electrode assembly
Sanying Hou, Hongqing Wang, Jianwei Ren, Yao Chen, Lang Shi, Shijun Liao
Abstract
Hydrophilic carbon nanotubes (HCNTs) were introduced into the membrane electrode assembly (MEA) to improve its low-humidity performance. The effects of types, placement, loading, and relative humidity on the MEA performance were investigated. It has been found that the MEA with 20 wt% HCNTs loading both in anode and cathode achieved the best self-humidifying performance. Its current density reached 1550 mA cm−2 at 0.6 V, with a maximum power density of 953 mW/cm2 at 70 °C, 30 psi and 30% relative humidity conditions. Besides, the stability test shows that its current density at 0.6 V only decreased by 6.4% after 44 h performance test, while the performance of blank MEA without HCNTs decreased by 45% within 6 h testing period. This extraordinary performance under low humidity condition is ascribed to that the HCNTs contained in the MEA improve the water management and mass transportation by functioning as a dispersant and hydrophilic agent.