Surface treatment method for bipolar plate of fuel cell

Abstract

The invention provides a surface treatment method for a bipolar plate of a fuel cell. The surface treatment method comprises the following steps: S1, cleaning the bipolar plate; S2, drying the cleanedbipolar plate; S3, preparing a nanoscale conductive hydrophobic layer on the surface of the dried bipolar plate; and S4, roughening the bipolar plate after the nanoscale conductive hydrophobic layeris prepared so as to improve the roughness of the nanoscale conductive hydrophobic layer. By the surface treatment method, the hydrophobic property of the surface of the bipolar plate can be improvedeffectively.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a method for treating the surface of a fuel cell bipolar plate. Background technique [0002] The fuel cell will produce water (hereinafter referred to as product water) during the working process. The current bipolar plate surface of the fuel cell has poor hydrophobic performance, and most of the water contact angles are lower than 90°, which is hydrophilic. The product water Easily attached to the surface of the bipolar plate. When the fuel cell operates at a low power, less water is produced, which adheres to the surface of the flow channel in the form of small water droplets, thus maintaining the smooth flow of gas in the flow channel. However, when the fuel cell operates at rated power, a large amount of water will be produced, which will exist in the flow channel in the form of water flow, and it is often difficult for the product water to be discharged out of the stack...

AI Technical Summary

Problems solved by technology

However, when the fuel cell operates at rated power, a large amount of water will be produced, which will exist in the flow channel in the form of water flow, and it is often difficult for the product water to be discharged out of the stack in time, thereby blocking the flow channel of the bipolar plate and causing large If the pressure drop is severe, it will cause the stack to be flooded and lack gas, causing irreversible damage to the stack

In addition, because the product water is slightly acidic, when it adheres to the surface of the metal bipolar plate for a long time, it will accelerate the corrosion of the metal bipolar plate in a high temperature and humid environment, increase the resistance of the metal bipolar plate, or from the surface of the metal bipolar plate A small amount of metal ions are corroded, which will poison the catalyst and eventually cause the performance of the stack to decline

Moreover, when purging, due to the strong adhesion of the product water on the surface of the bipolar plate flow channel, it is often difficult to quickly blow the product water out of the bipolar plate flow channel, so that the remaining residue on the surface of the bipolar plate during low temperature storage Water will freeze and even damage membrane electrodes

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