Fuel cell gas diffusion layer batch hydrophobic treatment method and production line thereof

Abstract

The invention discloses a fuel cell gas diffusion layer batch hydrophobic treatment method and a production line thereof, and the hydrophobic treatment method comprises the following steps: vacuumizing, filling an atomized water repellent solution, vacuumizing again, drying at a low temperature, roasting at a high temperature, cooling and filling air. According to the mode, continuous hydrophobicity of batch gas diffusion layers is achieved, the working efficiency is improved, high hydrophobicity uniformity is achieved, and potential safety hazards in the hydrophobicity calcination process can be reduced so as to save the cost; in the production line, the annular conveying track is utilized, and the metal sealing box can be repeatedly utilized under the condition that the metal sealing box does not need to be carried and transferred, so that hydrophobic treatment of large-batch diffusion layers is realized; and a hydrophobic treatment process is realized by combining a vacuumizing mechanism I, a hydrophobic solution atomizing mechanism, a vacuumizing mechanism II, a low-temperature heating oven, a high-temperature roasting furnace, a cooling chamber and other mechanisms.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a batch hydrophobic treatment method for a gas diffusion layer of a fuel cell and a production line thereof. Background technique [0002] The proton exchange membrane fuel cell is the most mature and the fuel cell closest to commercial application. Its basic components include: bipolar plate, gas diffusion layer, catalytic layer and proton exchange membrane; the gas diffusion layer, catalytic layer and proton exchange membrane constitute the membrane electrode structure. The gas diffusion layer is located between the catalytic layer and the bipolar plate. It is one of the key materials in the proton exchange membrane fuel cell. It is the outermost layer of the membrane electrode, providing contact between the electrode and the bipolar plate, and transporting reactants to the catalytic layer. And let the water generated by the reaction leave the electrode surface, allowing water to pas...

AI Technical Summary

Problems solved by technology

However, the concentration of polytetrafluoroethylene itself is too high, and it is generally chosen to dilute polytetrafluoroethylene, and then impregnate the carbon paper or carbon cloth in the solution, but when the carbon paper is directly immersed in the solution, it is impossible to guarantee the The water content in the area, and in the process of transfer, a large amount of solution drips, which further leads to the uneven content of polytetrafluoroethylene in each area of ​​the carbon paper, which leads to the uneven hydrophobicity of the carbon substrate, which directly affects the overall Properties of the diffusion layer

[0004] And because the carbon paper is a thin paper substrate, if the method of direct impregnation is used, it needs to be immersed in the water repellent solution under external pressure. Complete, that is, a certain amount of manpower is required to soak each carbon paper and transfer after the completion of the water repellency. This process consumes a lot of working time and cannot achieve continuous water repellency and batch carbon paper repellency in a short time. water treatment

In response to this problem, the patented continuous hydrophobic treatment equipment for fuel cell gas diffusion layer and its process (application number: CN202011475652.2) place sheets of carbon paper on the conveyor belt and spray water-repellent solution way to reduce labor costs and achieve continuous water-repellent treatment, but since carbon paper can only be laid flat on the conveyor belt, only one side of the carbon paper can be water-repellent at one time, so the patent also uses the effect of carbon paper The turning mechanism turns the carbon paper over so that the other side can also be sprayed with water repellent. Although this method can realize continuous production, the carbon paper has a large amount of water repellent solution sprayed on one side, and the turning process bears a lot of pressure. Carbon paper with a certain liquid weight is prone to damage during the flipping process, so its pass rate cannot be guaranteed

[0005] In addition, in the process of completing the hydrophobic sintering of carbon paper, the temperature is relatively high, above 350°C, and the inert gas must be continuously fed into the sintering furnace, otherwise the carbon substrate will burn when it encounters air at high temperature, which has a large potential safety hazards, but the sintering process is relatively long, generally takes 60-90min, and the continuous introduction of inert gas during this process will undoubtedly increase the cost that cannot be ignored

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