基于显微CT技术的碳纸微观结构特征分析  

Investigation of carbon paper micro-structure by micro computed tomography

作　　者：史启通 李冰[1] 冯聪[1] 明平文 张存满[1] SHI Qi-tong;LI Bing;FENG Cong;MING Pin-wen;ZHANG Cun-man(Clean Energy Automotive Engineering Center,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学新能源汽车工程中心,上海201804

出　　处：《复合材料科学与工程》2022年第6期65-69,104,共6页Composites Science and Engineering

基　　金：国家重点研发计划(2018YFB1502500)。

摘　　要：作为一种多功能高孔隙率碳纤维复合材料,碳纸在燃料电池中承担着传质、传热和导电等重要作用,其微观结构特征直接决定了燃料电池的性能和耐久性。本文利用显微CT扫描技术重建了碳纸的微观结构,并对其体积分数、孔径分布、碳纤维长度、弯曲度、空间方位角和倾斜角进行了测量和分析。主要结论有:①孔径服从正态分布,平均孔直径为30.95μm;②碳纤维长度和弦长服从三参数Weibull分布,平均弯曲度为1.03,表明纤维直线性较好;③方向角在0°~90°之间等概率分布,倾斜角大于45°的只占1.1%,说明碳纤维在XY平面上随机分布,只有少量的纤维呈垂直状态嵌入碳纸。最后本文指出了碳纸在微观结构上的一些显著性特征和缺陷。该项研究有助于提高人们对碳纸在燃料电池中作用的认知。As a kind of multifunctional and high porosity carbon fiber composite,carbon paper plays an important role in mass transfer,heat and electric conductivity in the fuel cell,and its micro-structure characteristics directly determine the performance and durability.In this paper,the micro-structure of carbon paper is reconstructed by micro computed tomography(CT).And the volume fraction,pore diameter distribution,carbon fiber length,tortuosity,orientation and slant angle are measured and analyzed.Results indicate that the pore diameters approximately obey normal distribution,and the average pore diameter is 30.95μm.The carbon fiber lengths and chord lengths obey 3-parameter Weibull distribution,and the average tortuosity is 1.03,which means that the fiber linearity is well.The orientation angle is distributed in the probability range of 0°~90°,and only 1.1%of the slant angle is more than 45°,indicating that the carbon fibers are randomly distributed on the XY plane,and only a small number of fibers migrate vertically into carbon.Finally,some distinct characteristics and defects in the micro-structure of carbon paper have been pointed out.This study is helpful to improve the understanding of the role of carbon paper in fuel cell.

关 键 词：碳纸 显微CT 微观结构 燃料电池 碳纤维复合材料 

分 类 号：TB332[一般工业技术—材料科学与工程]