Composite corrosion-resistant bipolar plate

Abstract

The utility model belongs to bipolar plate technical field, concretely relates to a kind of composite corrosion-resistant bipolar plate, including titanium nitride layer, titanium oxide layer and graphite layer sequentially arranged on substrate from inside to outside;Transition layer is equipped between titanium nitride layer and substrate, between titanium oxide layer and titanium nitride layer and between graphite layer and titanium oxide layer. Titanium oxide layer can be effectively set to enhance the corrosion resistance of metal bipolar plate;And setting titanium nitride layer can further enhance the corrosion resistance of metal bipolar plate. The graphite layer set can effectively enhance the conductivity of metal bipolar plate, while reducing contact resistance. Through the above structure setting, focus on improving the corrosion resistance of composite bipolar plate and reducing its contact resistance, thereby prolonging the service life of composite bipolar plate in fuel cell. Titanium layer is used as transition layer in composite bipolar plate, thereby effectively improving the bonding force between the multilayer film of bipolar plate.

Description

TECHNICAL FIELD

[0001] The utility model belongs to metal bipolar plate technical field, concretely relates to a composite corrosion -resistant bipolar plate. BACKGROUND

[0002] Metal bipolar plate is a key component in fuel cell, has excellent electric conductivity, thermal conductivity, machinability and compactness, has high strength, gas resistance and other advantages. Its manufacturing process mainly includes forming, welding, plating and packaging stages.

[0003] Metal bipolar plate is widely used in high power type electric pile, such as passenger car field. This material not only meets the commercial application requirements of high mechanical performance, good processing performance and abundant reserves, but also meets the practical application requirements of excellent electric conductivity and thermal conductivity. Metal bipolar plate is widely used in fuel cell field due to its excellent physical and chemical properties.

[0004] The corrosion resistance and contact resistance of common metal bipolar plate need to be improved, and the two are directly related to the service life of the composite bipolar plate in fuel cell;Therefore, it is necessary to improve it. Such as patent application no. 202321745190.0 utility model patent discloses a composite pre-coating and metal bipolar plate;Its ceramic transition layer uses transition metal nitride / transition metal carbide;The transition metal in the transition metal carbide is one or more of Cr, Ti, Nb, Zr, Ta and Mo. Its structure is not easy to form a dense film, and it cannot effectively block the penetration of H + Ion, poor corrosion resistance. UTILITY MODEL CONTENTS

[0005] In view of the above technical problems, the utility model provides a composite corrosion -resistant bipolar plate, which can improve the corrosion resistance of the bipolar plate, reduce the contact resistance, and effectively improve the service life.

[0006] In order to solve the above technical problems, the utility model adopts the technical scheme that:

[0007] A composite corrosion -resistant bipolar plate, including titanium nitride layer, titanium oxide layer and graphite layer arranged in the substrate from inside to outside;The transition layer is arranged between the substrate and the titanium nitride layer, between the titanium nitride layer and the titanium oxide layer and between the titanium oxide layer and the graphite layer.

[0008] The transition layer is titanium layer.

[0009] The substrate uses stainless steel.

[0010] The thickness of the substrate is 0.05-0.2 mm; the thickness of the titanium nitride layer is 10-500 nm; the thickness of the titanium oxide layer is 10-500 nm; the thickness of the graphite layer is 50-1000 nm; and the thickness of the transition layer is 10-500 nm.

[0011] The titanium nitride layer can be replaced by either an aluminum nitride layer or a hexagonal boron nitride layer.

[0012] The titanium oxide layer can be replaced by any one of the following: a cerium oxide layer, a zinc oxide layer, an aluminum oxide layer, or a graphene oxide layer.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] Adding a titanium oxide layer can effectively enhance the corrosion resistance of metal bipolar plates; while adding a titanium nitride layer can further enhance the corrosion resistance of metal bipolar plates. Adding a graphite layer can effectively enhance the conductivity of composite bipolar plates while reducing contact resistance. Compared with carbides, oxides, especially metal oxides, have stronger interatomic bonds and are more likely to form dense films, thus blocking H2O. + Ion penetration enhances the corrosion resistance of the bipolar plate in the overall structure.

[0015] The above structural design focuses on improving the corrosion resistance of the composite bipolar plate and reducing its contact resistance, thereby extending the lifespan of the composite bipolar plate.

[0016] In composite bipolar plates, a titanium layer is used as a transition layer, thereby effectively improving the bonding force between the multilayer films of the bipolar plate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Wherein: 1 is the substrate, 2 is the titanium nitride layer, 3 is the titanium oxide layer, 4 is the graphite layer, and 5 is the transition layer. Detailed Implementation

[0019] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0020] A composite corrosion-resistant bipolar plate is made by successively depositing nitrogen, titanium oxide and graphite layers on a metal bipolar plate to form a composite bipolar plate, which will have both good conductivity and corrosion resistance.

[0021] like Figure 1 As shown, it specifically includes a titanium nitride layer 2, a titanium oxide layer 3, and a graphite layer 4 disposed sequentially on the substrate 1 from the inside out;

[0022] A transition layer 5 is provided between the substrate 1 and the titanium nitride layer 2, between the titanium nitride layer 2 and the titanium oxide layer 3, and between the titanium oxide layer 3 and the graphite layer 4. The transition layer 5 is preferably a titanium layer.

[0023] The bipolar plate has a structure of substrate 1, titanium layer, titanium nitride layer 2, titanium layer, titanium oxide layer 3, titanium layer, and graphite layer 4. The hierarchical structure can effectively enhance the corrosion resistance of the metal bipolar plate, effectively improve the bonding force between the titanium nitride multilayer (thin film), and also enhance the electrical conductivity of the metal bipolar plate and reduce the contact resistance.

[0024] Further, the thickness of the substrate 1 is 0.05-0.2 mm, and preferably an ultra-thin stainless steel plate of 0.1 mm is used.

[0025] Further, the thickness of the titanium nitride layer 2 is 10-500 nm, the thickness of the titanium oxide layer 3 is 10-500 nm, the thickness of the graphite layer 4 is 50-1000 nm, and the thickness of the transition layer 5 (titanium layer) is 10-500 nm.

[0026] Further, in addition to the titanium nitride layer 2, an aluminum nitride layer or a hexagonal boron nitride layer can be used instead of the titanium nitride layer 2.

[0027] Similarly, the titanium oxide layer 3 can be replaced by any one of a cerium oxide layer, a zinc oxide layer, an aluminum oxide layer, or a graphene oxide layer. In addition to graphite, the graphite layer 4 can also use a graphite-like carbon layer, that is, an amorphous carbon, graphene, etc. with free electrons and good electrical conductivity.

[0028] The improvement of the bipolar plate lies in the hierarchical structure. Those skilled in the art can use the common magnetron sputtering technology and vacuum coating in the prior art to produce the bipolar plate, and the following examples are used to illustrate in detail:

[0029] Substrate 1 (substrate): an ultra-thin stainless steel plate of 0.1 mm is used. An 800-ton punch press is used to punch the stainless steel plate to make a metal monopolar plate substrate. Two metal monopolar plates are welded to make a metal bipolar plate substrate. The bipolar plate substrate is cleaned with cleaning agents and acid-base solutions to remove contaminants such as oil and oxides on the surface of the substrate.

[0030] A set of vacuum coating equipment is prepared, which includes a magnetron sputtering cathode target, an arc sputtering target, an ion source, a substrate base, and other components in the chamber.

[0031] The stainless steel substrate is placed in the vacuum chamber, and after pre-evacuation, argon gas is introduced, and the gas pressure in the chamber is about 1-5 mTorr. The ion source is turned on, and argon plasma is generated in the chamber. The plasma is used to clean the bipolar plate substrate and remove the oxide layer on the surface of the substrate.

[0032] Transition layer 5: a layer of titanium is deposited on the surface of the bipolar plate substrate as a transition layer 5 by using the magnetron sputtering technology.

[0033] Titanium nitride layer 2: a layer of titanium nitride is deposited on the surface of the previous titanium layer by using the magnetron sputtering technology, so as to effectively enhance the corrosion resistance of the bipolar plate.

[0034] Transition layer 5: a layer of titanium is deposited on the surface of the previous titanium nitride layer 2 as a transition layer 5 by using the magnetron sputtering technology.

[0035] Titanium oxide layer 3: a layer of titanium oxide is deposited on the surface of the previous titanium layer by using the magnetron sputtering technology, so as to further enhance the corrosion resistance of the bipolar plate.

[0036] Transition layer 5: a layer of titanium is deposited on the surface of the previous titanium oxide layer as a transition layer 5 by using the magnetron sputtering technology.

[0037] Graphite layer 4: a dense graphite layer 4 (thin film) is deposited on the surface of the previous titanium layer by using the arc discharge (ARC) technology, the graphite is a good conductive material, therefore, the graphite layer 4 (thin film) can effectively enhance the conductive performance of the composite bipolar plate, so as to reduce the contact resistance of the composite bipolar plate, and the structure of the composite bipolar plate is shown in Figure 1

[0038] During the vacuum coating, the bipolar plate substrate is heated by the substrate pedestal, and at the same time, the substrate is subjected to a proper negative bias voltage. Therefore, the deposition process of the titanium, titanium nitride, titanium oxide and graphite layer 4 (thin film) is also an annealing process, so as to ensure the density of the thin film.

[0039] The above only describes the preferred embodiments of the utility model in detail, but the utility model is not limited to the above-mentioned embodiments.​

Claims

1. A corrosion resistant bipolar plate of composite type, characterized in that: The application relates to a multilayer coating, which comprises, from inside to outside, a titanium nitride layer (2), a titanium oxide layer (3) and a graphite layer (4) arranged on a substrate (1) in sequence; transition layers (5) are arranged between the substrate (1) and the titanium nitride layer (2), between the titanium nitride layer (2) and the titanium oxide layer (3) and between the titanium oxide layer (3) and the graphite layer (4).

2. The corrosion resistant bipolar plate according to claim 1, wherein: The transition layer (5) is a titanium layer.

3. The corrosion resistant bipolar plate of claim 1, wherein: The substrate (1) is made of stainless steel.

4. The corrosion resistant bipolar plate according to claim 1 or 3, wherein: The thickness of the substrate (1) is 0.05-0.2 mm; the thickness of the titanium nitride layer (2) is 10-500 nm; the thickness of the titanium oxide layer (3) is 10-500 nm; the thickness of the graphite layer (4) is 50-1000 nm; and the thickness of the transition layer (5) is 10-500 nm.

5. The corrosion resistant bipolar plate according to claim 1 or 3, wherein: The titanium nitride layer (2) can be replaced by any one of an aluminum nitride layer or a hexagonal boron nitride layer.

6. The corrosion resistant bipolar plate according to claim 1 or 3, wherein: The titanium oxide layer (3) can be replaced by any one of a cerium oxide layer, a zinc oxide layer, an aluminum oxide layer or an oxidized graphene layer.

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