扩散层微观结构对DMFC阳极传质及性能的影响  

Effects of the microstructure of anode gas diffusion layer on mass transport and performance of DMFC

作　　者：田洋[1,2] 孙公权[1] 毛庆[1,2] 王素力[1] 高妍[1,2] 

机构地区：[1]中国科学院大连化学物理研究所,辽宁大连116023 [2]中国科学院研究生院,北京100039

出　　处：《电源技术》2009年第6期470-474,共5页Chinese Journal of Power Sources

摘　　要：通过调变微孔层中的PTFE含量,结合亲/憎水孔孔隙率、表面性貌等表征考察了扩散层的微观结构对其透水、透气性能的影响,并进一步研究了该阳极扩散层微观结构对DMFC阳极侧气、液传质和单池性能的影响。结果表明,当微孔层中PTFE含量为30%时,扩散层表面具有丰富且均匀的微米级大孔,亲/憎水孔孔隙率比例适中(3︰4),透水压和气体渗透系数大小合适(分别为0.01075MPa和2.743×10-12m2·s-1);由该扩散层组装的单电池甲醇渗透量较小,单位时间内阳极侧排出的CO2量较多,阳极侧气、液综合传质性能最好,电池性能最优,在80℃、常压、3倍空气剂量比时,最高比功率达90mW/cm2。Influence of the microstructure of anode gas diffusion layers （GDLs） on water permeability and gas permeation property was investigated by characterizing hydrophilic/hydrophobic porosities and surface morphologies, when PTFE content in microporous layers （MPLs） was adjusted. Further study was focused on the integrated effects of GDL microstructure on methanol and CO2 transport properties as well as the single cell performance. Experimental results show that GDL with 30% PTFE in the MPL has abundant and uniform micron pores. And a proper ratio of hydrophilic/hydrophobic porosities about 3：4 is obtained, leading to temperate water permeate pressure （0.010 75 MPa） and gas permeation coefficient （2.743×10^-12 m^2.s^-1）. Furthermore, low methanol crossover and large CO2 removal from the anode outlet is achieved meanwhile, when the above GDL is used as the anode GDL. Single cell performance reveals that the peak power density arrives at 90 mW·cm^-2, at 80℃, and ambient air pressure with stoichiometric of 3.

关 键 词：直接甲醇燃料电池 阳极扩散层 亲/憎水孔孔隙率 透水压 气体渗透性 甲醇及CO2传质 

分 类 号：TM911.4[电气工程—电力电子与电力传动]