质子交换膜燃料电池用炭纸制备工艺改进研究

发布时间：2018-01-18 06:31

本文关键词：质子交换膜燃料电池用炭纸制备工艺改进研究　出处：《湖南工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：炭纸作为燃料电池的气体扩散层,担负集流体、支撑催化剂、透气和排水的重要作用,其性能将直接对燃料电池的性能产生重要影响。本文着眼于对炭纸制备过程中常用的酚醛树脂浸渍剂进行改性,制备了具有更好的力学性能和物理性能的燃料电池用炭纸。首先,利用聚乙烯醇缩丁醛(PVB)对酚醛树脂进行改性,不仅改善了基体炭与炭纤维的相界面,而且使基体炭在炭纸中形成了良好的导电网络结构。研究采用两次浸渍的方法,在酚醛树脂中添加不同浓度的PVB对炭纸结构及性能的影响,并对样品的物理性能(强度、孔隙率、透气性、电阻率)和电池性能进行了表征。结果表明,随PVB含量的增加,炭纸的抗弯强度从36.75 MPa增加到52.28 MPa;电阻率从12.63 mΩ·cm下降到9.97 mΩ·cm;孔隙率略增加;透气性略降低。PVB浓度为0.06 mol/L时所制备的炭纸具有最好的综合性能,其电池的最大输出功率相比于未经PVB处理的炭纸提高了78%。其次,利用炭黑对经PVB改性的性能最优的炭纸做进一步改进。炭黑进入炭纤维间的孔隙中,形成了良好的导电网络,但同时改变了基体炭的结构。研究添加不同含量的炭黑对炭纸结构和性能的影响,并对样品的物理性能进行表征,结果表明:随着加入炭黑含量的增加,炭纸的厚度维持在0.170 mm左右;强度、孔隙率、透气性下降,电阻率先从10.58 mΩ·cm下降到6.64 mΩ·cm,后升高。为进一步优化炭纸性能,对其热处理温度进行了研究,对改性树脂进行了热重分析,进而制定炭化工艺曲线。对高温处理后炭纸的物理性能进行了表征,结果表明:随热处理温度的升高,炭纸的厚度、电阻率减小;强度、孔隙率、透气性下降。研究确定不同的高温处理后,炭纸厚度、密度、透气性、强度、导电性的变化规律,为制备不同性能要求的炭纸提供参考依据。
[Abstract]:As the gas diffusion layer of fuel cell, carbon paper plays an important role in collecting fluid, supporting catalyst, air permeability and drainage. Its performance will directly affect the performance of fuel cells. This paper focuses on the modification of phenolic resin impregnating agents commonly used in the preparation of carbon paper. Carbon paper for fuel cell with better mechanical and physical properties was prepared. Firstly, polyvinyl butyral (PVB) was used to modify phenolic resin, which not only improved the phase interface between carbon matrix and carbon fiber. Moreover, the carbon matrix formed a good conductive network structure in carbon paper. The effect of adding different concentration of PVB in phenolic resin on the structure and properties of carbon paper was studied by twice impregnation. The physical properties (strength, porosity, permeability, resistivity) and battery performance of the samples were characterized. The results showed that the physical properties of the samples increased with the increase of PVB content. The flexural strength of carbon paper increased from 36.75 MPa to 52.28 MPA; The resistivity decreased from 12.63 m 惟路cm to 9.97 m 惟路cm; Porosity increased slightly; The carbon paper prepared with slightly lower air permeability of 0.06 mol/L has the best comprehensive properties. The maximum output power of the battery is 78% higher than that of the untreated carbon paper without PVB. Carbon black is used to further improve the carbon paper modified by PVB. Carbon black enters the pores between carbon fibers and forms a good conductive network. At the same time, the structure of carbon matrix was changed. The effect of adding carbon black on the structure and properties of carbon paper was studied, and the physical properties of the sample were characterized. The results showed that the content of carbon black increased with the addition of carbon black. The thickness of carbon paper is about 0.170 mm; The strength, porosity and permeability decreased, the resistivity decreased from 10.58 m 惟路cm to 6.64 m 惟路cm, and then increased. In order to further optimize the properties of carbon paper. The heat treatment temperature was studied, the thermogravimetric analysis of the modified resin was carried out, and the carbonization process curve was established. The physical properties of the carbon paper after high temperature treatment were characterized. The results show that the thickness and resistivity of carbon paper decrease with the increase of heat treatment temperature. The changes of carbon paper thickness, density, permeability, strength and conductivity are determined after different high temperature treatment, which provides a reference for the preparation of carbon paper with different properties.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM911.4

【参考文献】