燃料电池用碳纸的制备及其石墨化研究

Study on Preparation and Graphitization of Carbon Paper for Fuel Cell

关键词:  燃料电池  碳纤维无纺布  碳纸  石墨化

Key Words:fuel cell  carbon fiber non-woven  carbon paper  graphitization

摘要:以聚丙烯腈（PAN）基碳纤维无纺布为骨架，通过酚醛树脂乙醇溶液浸渍、模压和碳化，再经不同温度石墨化处理，制备了燃料电池用碳纸。通过现代分析仪器表征碳纸原纸的微观形貌、平面方向电阻率、孔隙分布、拉伸强度等指标，探讨石墨化温度对碳纸原纸各项性能的影响。结果表明，在石墨化处理过程中，大块聚集且杂乱无章的树脂炭能够逐渐收缩到碳纤维表面及碳纤维与碳纤维的交结点上，获得较完美的石墨晶体结构。石墨化温度需大于2000 ℃，才能获得具有较好性能且满足应用要求的碳纸原纸。当石墨化温度为2000 ℃时，碳纸原纸的平面方向电阻率为19.0 mΩ·cm，拉伸强度达17.8 MPa，孔隙率达79.15%。

Abstract:With polyacrylonitrile （PAN） based carbon fiber non-woven fabric as the backbone， carbon paper for fuel cell was prepared by impregnating with phenol-formaldehyde ethanol solution， molding and carbonizing， then graphitized at different temperature. The effects of different graphitization temperature on the properties of carbon paper base paper were investigated by modern analytical instruments， including microscopic morphology， in-plane resistivity， pore distribution， tensile strength， and other indicators. The results showed that the large aggregated and disordered resin carbons were gradually shrunk to the surface of carbon fiber and the intersection point of carbon fiber with each other during the graphitization process， obtaining a more perfect graphite crystal structure. The carbon paper base paper could be obtained with good performance to meet the application requirements of the gas diffusion layer after being graphitized at least at 2000 ℃. When the graphitization temperature was 2000 ℃， the carbon paper base paper was prepared with the in-plane resistivity of 19.0 mΩ·cm， the tensile strength of 17.8 MPa， and the porosity of 79.15%.