中文摘要：

采用扫描电子显微镜（SEM）、汞注入孔隙计（MIP）和电化学方法考察了4种常用的阳极扩散层———碳布、碳纸、XC-72碳粉修饰的碳纸（以下简称XC-72）、碳纳米管扩散层———对直接甲醇燃料电池性能的影响.结果表明：碳纳米管扩散层在1 000～3 000nm具有丰富的孔径分布和最大孔隙率;碳纸和XC-72扩散层组装的单电池在大电流密度下分别由于孔径大不利于输水和孔径小不利于输气而使得电池性能较差;碳布扩散层组装的单电池虽然具有最大的甲醇扩散系数,但是由于其厚度问题使得性能稍差于碳纳米管扩散层电池.阳极极化结果也表明碳纳米管扩散层电池具有最小的甲醇传质阻力.因此碳纳米管扩散层组装的单电池具有最优性能,最大电流密度为460mA·cm^-2,最大功率密度为110mW·cm^-2.

英文摘要：

Comparative studies of four common-used anode gas diffusion layers（A-GDLs）,namely carbon cloth,carbon paper,carbon paper based on XC-72（in short XC-72）and GDL made of carbon nanotubes（CNT）for direct methanol fuel cells（DMFCs）were carried out and discussed.The results of scanning electron microscope（SEM）,mercury intrusion porosimeter（MIP）and electrochemical test show that CNT has large pore size distribution in pore size of 1 000-3 000nm and the largest total porosity compared with those of the other three.Carbon paper and XC-72show disadvantageous influences on cell performances at high current density,because carbon paper has many large pores which are unsuited for water transport,while XC-72has many small pores which are unsuited for gas transport.Though cell with carbon cloth has the highest methanol diffusion coefficient,it shows a little lower performance than that with CNT due to its thickness.Anode polarization（AP）results also display that the cell with CNT has the least methanol mass transfer resistance.As a result,the cell with CNT shows the best performance with the highest limiting current density and peak power density of 460 mA·cm^-2 and 110mW·cm^-2,respectively.