A kind of preparation method of metal graphite composite bipolar plate of proton exchange membrane fuel cell

Abstract

A method for preparing a metal-graphite composite bipolar plate for a proton exchange membrane fuel cell, comprising making the metal bipolar plate, treating flexible graphite paper, and adhering the flexible graphite paper on the surface of the bipolar plate. The making of the metal bipolar plate includes: molding a stainless steel sheet The hydrogen unipolar plate and the oxygen unipolar plate, the unipolar plates have a corrugated flow field structure, and are welded together by fiber laser to form a bipolar plate; the treatment of flexible graphite paper and the adhesion of flexible graphite paper on the surface of the bipolar plate include: Graphite paper is vacuum-impregnated in resin, and the impregnated flexible graphite paper is pressed on the front and back surfaces of the bipolar plate, and the resin is cured in the furnace to obtain the finished metal-graphite composite bipolar plate. The beneficial effects of the invention are: simple process, low cost; small bipolar plate resistance; corrosion resistance and long service life.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a method for preparing a metal-graphite composite bipolar plate for a proton exchange membrane fuel cell. Background technique [0002] Proton exchange membrane fuel cells directly convert the chemical energy in hydrogen and oxygen into electrical energy without being limited by the Carnot cycle, so they have high energy conversion efficiency and are environmentally friendly, and can be widely used in transportation and ground power generation. However, the voltage of a single battery is low (0.6V ~ 1.0V). Therefore, in order to obtain a practical voltage, it is necessary to connect multiple single batteries in series. , oxygen, collecting current and supporting membrane electrodes, and also responsible for the heat dissipation and drainage functions of the entire battery system, so the bipolar plate material needs to be corrosion-resistant, conductive, good mechanical strength and low ...

AI Technical Summary

Problems solved by technology

[0004] The deficiencies of existing metal bipolar plates coated with corrosion-resistant conductive coatings are: first, the service life of the corrosion-resistant conductive coatings of metal bipolar plates is relatively low, and cannot meet the life requirements of 5,000 hours to 10,000 hours of service life of fuel cells; The cost is relatively high, which cannot meet the low-cost requirements of fuel cells

Precious metals, such as platinum and gold, can meet the electrical conductivity and corrosion resistance requirements of the fuel cell working environment, and the service life can also meet the requirements of commercial applications, but they are expensive and cannot be used in commercial applications

Nitride, carbide, and boride have good electrical conductivity. The main problem is that their expansion coefficient is quite different from that of the metal plate, and they are easy to fall off during the fuel cell’s operating temperature cycle, resulting in a service life of the bipolar plate that cannot meet the commercialization requirements of the fuel cell. ; At the same time, this type of material is a semiconductor, and its contact resistance with the electrode carbon material is relatively high, and the voltage loss is relatively large when working at a high current

Sputtered carbon film, including carbon, chromium carbide, and titanium carbide composite coating, can meet the discharge requirements of fuel cells in terms of contact resistance, but its detachment and easy corrosion lead to a short service life, which cannot meet the commercialization needs of fuel cells

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