High-performance bipolar plate with graphene-reinforced surface for fuel cell and preparation method of high-performance bipolar plate

Abstract

The invention relates to the technical field of fuel cells, and provides a high-performance bipolar plate with a graphene-reinforced surface for a fuel cell and a preparation method of the high-performance bipolar plate. A titanium bipolar plate is adopted as a substrate, and by adopting magnetron sputtering apparatus and method, a nickel layer or nickel-chromium layer, a first gold layer, a first graphene layer, a second gold layer and a second graphene layer are sequentially deposited on the surface of the self-sputtered and cleaned titanium bipolar plate substrate. The nickel layer or nickel-chromium layer, the first gold layer and the second gold layer which are few in pore defects and uniform in thickness can be prepared; the binding force between the first gold layer and the titanium bipolar plate substrate is improved by using the nickel layer or nickel-chromium layer, so that the problems of reducing the total contact resistance and improving the corrosion resistance of the titanium bipolar plate in the using process are solved; oxygen around the nickel layer or nickel-chromium layer, the titanium bipolar plate substrate and a cathode can be isolated by using the gold layer, so that oxidation of the nickel layer or nickel-chromium layer and the titanium bipolar plate substrate is avoided; and by adopting the graphene layers, the surfaces of the gold layers have high hydrophobicity and the separated carbon particles in the preparation process of graphene have a good pore blocking effect.

Description

technical field [0001] The invention belongs to the technical field of fuel cells, in particular to a fuel cell bipolar plate with enhanced surface and a preparation method thereof. Background technique [0002] There are many types of fuel cells, among which the proton exchange membrane fuel cell (PEMFC) is an efficient and clean green power source, which has the advantages of high energy conversion efficiency, low operating temperature, fast start-up, high specific power, and long life. Widely used in electric vehicles, distributed power stations and portable power supplies. [0003] The bipolar plate is the main component in the proton exchange membrane fuel cell, accounting for about 70% of the total weight of the proton exchange membrane fuel cell and more than 50% of the total cost of the proton exchange membrane fuel cell. The role of the bipolar plate is to separate the reaction gas, collect and conduct current, support the membrane electrode, and undertake the heat...

AI Technical Summary

Problems solved by technology

[0006] However, the gold layer is prepared by electroplating on the surface of the titanium bipolar plate substrate. This electroplating method will cause the bonding force between the gold layer and the titanium bipolar plate substrate to be small, which will easily lead to the appearance of gold in the titanium bipolar plate during use. Phenomenon of layer peeling and caving

[0007] On the other hand, since the electroplated gold layer prepared on the surface of the titanium bipolar plate substrate generally has many micropore defects, if these micropores are not blocked, the oxygen distributed in the cathode will diffuse through the micropores directly to the titanium bipolar plate substrate, making The titanium bipolar plate substrate is oxidized, which eventually leads to an increase in the overall contact resistance and reduces the output voltage of the fuel cell

And the temperature rise of the fuel cell caused by the increase of the contact resistance of the titanium bipolar plate will also affect the activity of the catalyst in the fuel cell.

In addition, the microporous defects of the electroplated gold layer will also cause the electrochemical corrosion of the titanium bipolar plate substrate as an anode, causing the gold layer to fail prematurely

When the situation is serious, the titanium bipolar plate substrate will eventually lead to the peeling and collapse of the electroplated gold layer on the surface under the action of various mechanisms such as cathodic oxidation and electrochemical corrosion.

[0008] In addition, the hydrophobicity of the surface of the general gold layer is not high, and the blockage at the end of the flow field of the titanium bipolar plate is also one of the main reasons for the rapid decline in the operating performance of the stack assembled with the titanium bipolar plate.

[0009] Therefore, the main problems faced by fuel cell bipolar plates with gold-plated structure on the surface of the titanium bipolar plate substrate are: how to improve the bonding force between the gold layer and the titanium bipolar plate substrate, and prevent the gold layer from peeling off and collapsing; Under the premise of thinner thickness, block its micropore defects; how to modify the surface of the gold layer to improve the hydrophobic characteristics of the fuel cell bipolar plate surface, so as to greatly improve the corrosion resistance and durability of the fuel cell bipolar plate

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