中文摘要：

采用化学气相沉积（CVD）法在炭纸上原位生长碳纳米纤维（CNF）成功制备了燃料电池用碳纳米纤维基气体扩散层（CNF/GDL）。通过调变CNF生长时间（从10 min到40 min）获得了一系列结构、形貌不同的碳纳米纤维层。为了研究CNF层结构、形貌对碳纳米纤维基气体扩散层性能的影响,对样品的物理性能（表面形貌、接触角、导电性、透气性）和电池性能进行了表征。物理性能测试结果表明：随着CNF生长时间的延长,气体扩散层的疏水性提升,电子传导能力先提升后下降。单电池测试结果显示：在低、中电流密度区域（i〈1 700 m A/cm2）,采用CNF生长时间为20 min的气体扩散层制备的电池表现出更优异的电池性能;在高电流密度区域（i〉1 700 m A/cm2）,采用CNF生长时间为10 min的气体扩散层制备的电池性能更好。

英文摘要：

In-situ grown carbon nanofibers on carbon paper as an integrated GDL for PEMFCs was fabricated by a chemical vapor deposition process. A series of GDLs with different features were obtained by varying growth time from 10 to 40 min. The characteristics of the GDL samples involving morphology, contact angle, electrical conductivity, gas permeability, were evaluated and fuel cell performance of the GDLs was measured by a single cell test with hydrogen/air. The results show that, with increasing CNF growth time, the hydrophobicity of the GDLs increases while the electdcal conductivity first descends, and then begins to increase. In the low and medium current density region, an optimum power density was obtained from the CNF layer growing for 20 min. In the high current density region, an optimum power density was obtained from the CNF layer growing for 10 min.