质子交换膜燃料电池用炭纤维纸的制备和表征

Preparation and characterization of carbon fiber paper for application of proton exchange membrane fuel cell

采用干法成型技术制备聚丙烯腈(PAN)基炭纤维纸坯体,将其经树脂浸渍、热压、炭化、石墨化处理后制备成轻量化炭纤维纸。利用扫描电子显微镜(SEM)观察炭纤维纸及坯体的显微结构,利用X射线衍射仪测试不同温度处理后的石墨化度,并利用四探针法测试炭纤维纸的导电性能,透气性采用压差法进行测试。结果表明:石墨化温度是影响炭纤维纸电阻率的关键因素,而密度对电阻率的影响较小;透气性随厚度和体积密度的增加而降低;制备的炭纤维纸厚度为0.11mm、密度为0.65g/cm3,将其经2000℃石墨化处理后,采用Pt载量0.5mg/cm2的Core112CCM为膜电极,在H2与空气的流量比为1.2-5、温度60℃、常压条件下进行单体电池性能测试,电流密度为500mA/cm2时输出电压为0.6V,电池输出性能较好。

The carbon fiber paper （CFP） was prepared from polyacrylonitrile （PAN） based carbon fiber through impregnation with resin, mould pressing, carbonization and graphitization. The microstructures of CFP perform and resultant CFP were analyzed by SEM. The degree of graphitization of CFPs heat treated at different temperatures was investigated by XRD. The gas permeability and electrical property were measured by differential pressure method and four-probe technique, respectively. The results indicate that the graphitization temperature has larger impact than bulk density on the electrical resistivity of CFP. The gas permeability decreases with the increase of thickness and bulk density of CFP. A suitable CFP with thickness of 0.11 mm, and bulk density of 0.65 g/cm3 is developed. When using Core112CCM with 0.5 mg/cm2 Pt as membrane electrode, the optimum properties of the CFP are achieved by restricting the heat treatment temperature to only 2 000 ℃ under the conditions of gas flow rate ratio of H2 to air 1.2-5, atmospheric pressure 60 ℃, output voltage 0.6 V and current density 500 mA/cm2.