梯度孔径结构微孔层对质子交换膜燃料电池性能影响

Effect of microporous layer with gradient pore structure on the performance of proton exchange membrane fuel cell

气体扩散层(GDL)是质子交换膜燃料电池(PEMFCs)核心部件之一,微孔层(MPL)对PEMFCs水管理和性能具有重要作用。利用导电炭黑、MWCNTs和石墨片孔径分布的差异分层涂覆热处理制备梯度孔径结构微孔层,研究了其对PEMFCs水管理的影响。3层设计的渐变梯度孔径结构微孔层G4,在微孔层载量为1.6 mg/cm^(2),电流密度为5.5 A/cm^(2)下仍未出现明显传质极化,并在电流为17.00 A时其功率密度最大为1855 mW/cm^(2),比商业AvCarb GDS3260提升了21%。且在900 s内0.45 V恒定电压下,其电池输出性能稳定性极佳,水淹次数仅为4次。

The gas diffusion layer(GDL)is one of the core components of proton exchange membrane fuel cells(PEMFCs),and the microporous layer(MPL)plays an important role in the water management and performance of PEMFCs.In this paper,the carbon ma-terials with different pore size distribution including conductive carbon black,MWCNTs and graphite sheets are used to prepare a microporous layer with gradient pore structure by layer coating and heat treatment,and the effect on water management of PEMFCs is studied.When the loading capacity of the microporous layer is 1.6 mg/cm^(2),the three-layer design of the gradual gradient pore structure named microporous layer G4 does not show obvious mass transfer polarization at a current density of 5.5 A·cm^(-2),and when the current is 17.00 A,the maximum power density is 1855 mW·cm^(-2),which is 21%higher than that of the commercial AvCarb GDS3260.And at a constant voltage of 0.45 V within 900 s,the battery output performance is extremely stable.It also counts the number of flooding times under a constant voltage of 0.45 V in 900 s,which is only 4 times.