Pore blocking method for surface modified layer of fuel cell polar plate

Abstract

The invention provides a pore blocking method for a surface modified layer of a fuel cell polar plate. According to the pore blocking method, a film is plated by using a physical vapor deposition method. The pore blocking method for the surface modified layer is characterized in that after a bipolar plate is plated with the film in a vacuum chamber of film plating equipment, the inner pressure of the vacuum chamber of the film plating equipment reaches 0.1*10<-3>Pa-10.0*10<-3>Pa and the temperature is 100-180 DEG C; an air inlet valve is switched on and air enters; the range of the pressure in the vacuum chamber of the film plating equipment is 1.1*10<-2>Pa-1.1*10<5>Pa; when air is naturally cooled to 20-50 DEG C along the equipment, the vacuum chamber is opened to finish oxidation pore blocking treatment. The pore blocking method has the beneficial effects that temperature and vacuum degree conditions of the equipment after the physical vapor deposition method is used for plating the film are utilized effectively; the modified layer is subjected to pore blocking in a natural cooling process of the equipment and the production efficiency is improved obviously; new equipment and materials do not need to be added, no energy source is consumed and the processing cost is low; the pore blocking method is only used for oxidizing a micro-pore; the corrosion resistance of the bipolar plate is improved under the precondition of guaranteeing that the electrical conductivity is not changed so that the service life is prolonged.

Description

technical field [0001] The invention belongs to the technical field of fuel cells, and in particular relates to the surface modification treatment technology of metal pole plates of proton exchange membrane fuel cells. Background technique [0002] The bipolar plate is an important part of the proton exchange membrane fuel cell, which needs to have excellent electrical conductivity and corrosion resistance. In order to improve the specific power density of the stack, metal bipolar plates are considered to be an inevitable choice for fuel cell vehicles. Therefore, it is of great significance to prepare corrosion-resistant conductive coatings on metal plates. In the existing technology, there are only two types of technical routes where the modification method is feasible for mass production and the modified layer has both corrosion resistance and electrical conductivity: one is electroplating precious metals, and the other is ion-plating carbon-based multilayer composite fil...

AI Technical Summary

Problems solved by technology

The deficiencies of these two types of methods in the prior art are: electroplating will produce a large amount of pollution, which is contrary to the green concept of fuel cells, and the cost of precious metals is very high; Large-scale production, environmentally friendly process

The metal ions produced by corrosion can also contaminate the electrode, resulting in a decrease in battery performance; severe corrosion of the bipolar plate will lead to perforation, seriously affecting the durability and safety of the coated bipolar plate

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