Preparation Of A New Carbon Fiber Paper

The four key materials of Fuel cell are: the Bi-electrodes material,thecatalyst material,the proton exchange membrane material and the diffusionlayer material of carbon paper. As the gas diffusion layer material of electrode offuel cell, carbon paper should have the following advantages: high electricconductivity,excellent permeability,low cost of manufacture and properperformance-price ratio.The carbon fiber is the main material for preparing carbon paper. Theelectrical conductivity of the carbon paper depends on the degree ofgraphitization. The current technology of carbon fiber graphitizing is using thetubular electrical furnace, through which the carbon fiber is graphitized. In thisprocess of graphitizing, the operation is intermittent, the heat efficiency is low,the technique is complicated, especially the equipment is expensive. In ourcountry, graphitized carbon fibers can not be mass-produced while the westcountries embargo graphitized carbon fibers to our country. Recently, XinmouScience & Technology Company has made a big progress in preparinggraphitized carbon fibers, a new technology has been developed, namely theradio-frequency plasma method to prepare graphitized carbon fibers.In this paper, the carbon fibers made by radio-frequency plasma method were used for carbon paper. The self-making carbon paper has beencharacterized by the method of XRD,SEM and HRTEM in the dimensions ofmicrons and nanometers. The degree of graphitization of the carbon paper isG=19.8%, the interlayer distance is d₀₀₂=0.3421nm, the average sheetresistivity of the self-made paper is 1.13Ω·cm^-2, the average volume resistivityis 0.0340Ω·cm. Comparing with the Toray carbon paper, the conductibility andthe permeability of the self-made carbon paper are approaching to which of theToray carbon paper.The graphitized carbon fiber of the radio-frequency plasma method hascome to industrialization; the experimental results indicate that the carbon fibermeets the particular requirements of carbon paper. Furthermore, theradio-frequency plasma method reduces the cost considerably, comparing withthe traditional method. So making carbon paper by using the graphitized carbonfiber of the radio-frequency plasma method will provide a new way forindustrialization of the key material of Fuel Cell-carbon paper in China.