CN102306813B - Fuel cell bipolar plate prepared through metal sheet stamping and forming, and application thereof - Google Patents

Abstract

The invention discloses a fuel cell bipolar plate stamped and formed by a thin metal plate, which comprises two identical gas flow field single plates and an intermediate flow field single plate, which are respectively used as an oxidant flow field plate, a fuel gas flow field plate and a cooling plate. The liquid flow field plate, the two gas flow field veneers pass through their surrounding contact surfaces, the sealing material placed in the sealing groove of the frame, the filling and leveling material placed in the filling area, and the contact surfaces on both sides of the middle flow field veneer, respectively Connect the two sides of the middle flow field veneer to form the fuel cell bipolar plate; each flow field veneer is provided with three inlets and three outlets, which are: oxidant inlet, coolant inlet, fuel gas Inlet, Oxidant Outlet, Coolant Outlet and Fuel Gas Outlet. The fuel cell bipolar plate of the present invention adopts three metal veneers superimposed through the frame sealing structure to form a bipolar plate, and the other side of the gas flow field veneer corresponding to the ridge of the gas flow area is the liquid flow field groove and cooling The liquid flow field groove on the liquid veneer is configured as a coolant flow channel, which avoids the shortcomings of local deformation of the bipolar plate caused by laser welding and high welding quality requirements. The structure is easy to realize, the assembly process requirements are simple, and the cost is low.

Description

A fuel cell bipolar plate formed by stamping metal sheet and its application

technical field

The invention relates to the field of manufacturing bipolar plates of fuel cells, in particular to a thin metal fuel cell bipolar plate and its application.

Background technique

Because the proton exchange membrane fuel cell (PEMFC) has the advantages of cleanness, high efficiency, and renewable energy, it is expected to replace conventional engines as the main power source for future vehicles. The structure of a proton exchange membrane fuel cell is mainly composed of bipolar plates, proton exchange membranes, catalysts, etc. Among them, the membrane electrode (MEA) is the core of the fuel cell, and the bipolar plate, one of the key components of the PEMFC, not only occupies the fuel cell stack 70%-80% of the weight, and it also occupies a considerable proportion in the production cost of the fuel cell stack. Graphite bipolar plates with good electrical conductivity and easy processing of flow fields have laid a good start for the commercialization of PEMFC, and are also widely used in PEMFC. lack of sufficient competitiveness. Composite graphite plates, flexible graphite and thin-layer metal plates are very potential bipolar plate replacement materials. Compared with graphite materials, metal thin plates have good machinability, excellent electrical conductivity, thermal conductivity and compactness. , easy to achieve thin bipolar plates, greatly reduce the volume and weight of bipolar plates, and low price, easy to achieve large-scale mass production, will become the preferred material for reducing fuel cell plates. The requirements for the use of bipolar plates in direct methanol fuel cells, proton exchange membrane water electrolyzers and regenerative fuel cells are similar to those of the aforementioned proton exchange membrane fuel cells.

After searching the prior art documents, it is found that the Chinese patent publication number is CN 1416184A, and the patent document titled "a metal composite bipolar plate for a proton exchange membrane fuel cell" uses a strip-shaped electrode opposite to the three-in-one electrode. The groove part and the metal frame part are integrally formed by bonding or welding. This patent uses two metal plates as the cathode and anode plates of the fuel cell respectively, which are connected with the metal frame to form a bipolar plate, which is in the form of a metal plate. Although it is easier to realize in terms of structure, the gas flow field is limited to interdigitated The flow field structure, the pressure drop of the gas flow is large, and the flow field is formed by bonding or welding. The bipolar plate is locally deformed by laser welding, and the welding quality is high, and the adhesive may pollute the electrode during long-term use. .

The Chinese Patent Publication No. is CN 101183723A, and the patent document titled "Proton Exchange Membrane Fuel Cell Bipolar Plate Formed by Metal Sheet" is that two identical single plates are connected symmetrically by welding, and the gas flow channel is interdigitated. , the coolant flow channel adopts a serpentine flow channel in the form of a metal plate. Although it is light in weight and small in size, it also requires the gas flow field to adopt an interdigitated shape. In order to reduce the pressure drop of the interdigitated flow field and improve the reaction efficiency, There are several shallow grooves on the ridge of the flow field, which cause the gas pressure drop to be larger than that of the serpentine flow channel and increase the difficulty of mold manufacturing. The flow field is welded together, and there is also local deformation of the bipolar plate caused by laser welding, and welding quality requirements high.

Therefore, those skilled in the art are devoting themselves to developing a novel metal-based fuel cell bipolar plate.

Contents of the invention

In view of the above-mentioned defects of the prior art, the object of the present invention is to overcome the deficiencies of the prior art and provide a fuel cell bipolar plate formed from a thin metal plate. The fuel cell bipolar plate of the present invention is assembled by stacking three metal plates to meet the three inputs and three outputs required by the fuel cell, that is, the oxidant inlet, the cooling liquid inlet, the fuel gas inlet, the oxidant outlet, the cooling liquid outlet and the fuel gas exit.

In order to achieve the above purpose, the fuel cell bipolar plate of the present invention is realized through the following technical solutions.

The fuel cell bipolar plate stamped and formed by the metal thin plate of the present invention includes two identical gas flow field single plates and an intermediate flow field single plate, which are respectively used as an oxidant flow field plate, a fuel gas flow field plate and a coolant flow field plate , the two gas flow field veneers are respectively connected to the middle through the contact surfaces around them, the sealing material placed in the sealing groove of the frame, the leveling material placed in the leveling area, and the contact surfaces on both sides of the middle flow field veneer. Both sides of the flow field single plate are combined to form the fuel cell bipolar plate; each flow field single plate is provided with three inlets and three outlets, which are: oxidant inlet, cooling liquid inlet, fuel gas inlet, and oxidant outlet , coolant outlet and fuel gas outlet.

In the specific implementation of the present invention, preferably, the flow field veneer is in the shape of a rectangle.

In a preferred embodiment of the present invention, one side of the gas flow field veneer is a reaction gas flow area, and the ridge corresponding to the gas flow area on the other side of the gas flow field veneer is a liquid flow field groove ;

One side of the middle flow field veneer is a flow field groove formed by stamping, which is configured with the liquid flow field groove of the gas flow field plate to form a cooling liquid flow channel;

The gas flow field veneers are respectively an oxidant flow field veneer and a fuel gas flow field veneer;

The flow field on both sides of the flow field veneer (including the oxidizer flow field veneer, the fuel gas flow field veneer, and the coolant fluid veneer) and the periphery of the fluid inlet and outlet form a sealing groove to place a sealing material, and its depth is the same as the said flow field veneer. The depth of the flow field grooves is the same.

The groove in the middle region of the gas flow field veneer surrounded by the sealing material is a fluid flow field.

In a preferred embodiment of the present invention, the gas flow field veneer groove frame needs to be filled with rubber-like elastic materials such as silicone rubber heat-resistant and aging-resistant rubber, etc., and the flow field veneer The contact surface is even. The area that needs to be filled is only on the gas flow field plate to prevent the coolant from remaining in the groove and not flowing out. The groove frame of the fuel gas inlet and outlet part opposite to the electrode plate and the cooling liquid plate is filled with elastic material to make it flat.

The gas flow area and the cooling liquid flow channel are preferably serpentine flow fields, but not limited to serpentine flow fields.

In a preferred embodiment of the present invention, the flow field groove has a width of 0.5-2m and a depth of 0.2-0.5mm; the sealing groove has a width of 1-4mm and a depth of 0.2-0.5mm.

In the fuel cell bipolar plate of the present invention, a circular positioning hole is provided at the middle of the two sides of the flow field single plate parallel to the length direction of the flow field groove; the oxidant inlet, the cooling liquid inlet and The fuel gas inlet, the oxidant outlet, the cooling liquid outlet and the fuel gas outlet are arranged in sequence, and the inlet and outlet are on opposite sides of the flow field veneer.

In the fuel cell bipolar plate of the present invention, the sealing material is a sealing gasket, which is placed in the sealing groove of each flow field plate. In the present invention, the sealing material is used for sealing the groove, and mainly plays a role of sealing. The main requirement is elastic rubber with good heat resistance (greater than 120° C.) and aging resistance, and the commonly used material is silicon rubber.

In the fuel cell bipolar plate of the present invention, the leveling material that needs to be filled in the leveling area is similar to the sealing material, and is placed in the leveling area of each gas flow field plate. The main requirement for the leveling material is heat resistance (greater than 120°C) and rubber materials with good aging resistance, the commonly used materials are rubber-like elastic materials such as fluorine rubber or silicone rubber.

In the fuel cell bipolar plate of the present invention, the flow field single plate is made of metal sheet material, preferably one of stainless steel, titanium and titanium alloy metal sheet materials, more preferably stainless steel.

In the fuel cell bipolar plate of the present invention, the single plate of the gas flow field and the single plate of the intermediate flow field are formed by pressing the sealing material by external force to form a whole and realize the sealing, so as to form the bipolar plate of the fuel cell plate.

In the fuel cell bipolar plate of the present invention, the thickness of the metal thin plate is 0.1mm-0.3mm, and the material of the gas flow field single plate and the intermediate flow field single plate is selected from stainless steel, titanium and titanium alloy metal thin plates one of the materials.

Compared with other fuel cell metal bipolar plates in the prior art, the bipolar plate of the present invention adopts three metal flow field single plates, on which the oxidant (air or oxygen) gas flow channel and cooling liquid channel are punched out respectively and fuel gas channels. Sealing grooves are machined between the three boards, sealing materials are placed, and then they are pressed together by external force to form a whole without bonding or welding. When assembling into a battery, external force can be used, and the requirements for bonding or welding processes are relatively simple.

The fuel cell bipolar plate punched and formed by the metal thin plate of the present invention can be used in proton exchange membrane fuel cells, and can also be used as bipolar plates in direct methanol fuel cells, proton exchange membrane water electrolyzers and regenerative fuel cells.

Another object of the present invention is to provide a proton exchange membrane fuel cell, which comprises the fuel cell bipolar plate stamped and formed from the aforementioned thin metal plate of the present invention.

The fuel cell bipolar plate punched and formed by the metal thin plate of the present invention has the advantages of light weight, small volume, simple production process, low cost, and easy realization of mass production.

The fuel cell bipolar plate stamped and formed by the metal thin plate of the present invention adopts three metal veneers superimposed through the frame sealing structure, and the sealing material is pressed by external force, so that the flow field veneers are combined into one body, and the two plates are jointly constructed into a The coolant flow channel avoids the disadvantages of local deformation of the bipolar plate formed by laser welding and high welding quality requirements, the structure is easy to realize, and the assembly process requirements are simple.

The idea, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the fuel cell bipolar plate of the present invention.

Fig. 2 is a front view of the gas flow field single plate 2 of the fuel cell bipolar plate of the present invention.

FIG. 3 is a schematic perspective view of the gas flow field single plate 2 of the fuel cell bipolar plate of the present invention.

Fig. 4 is a front view of the intercooler flow field single plate 5 of the fuel cell bipolar plate of the present invention.

FIG. 5 is a schematic perspective view of the intermediate coolant flow field single plate 5 of the fuel cell bipolar plate of the present invention.

FIG. 6 is a schematic diagram of the gas flow field single plate 2 filling the area 3 of the fuel cell bipolar plate of the present invention.

FIG. 7 is a schematic diagram of the gas flow field single plate 8 filling the region 7 of the fuel cell bipolar plate of the present invention.

FIG. 8 is a schematic view of the flow channel formed between the gas flow field single plate 2 and the cooling liquid single plate 5 of the fuel cell bipolar plate of the present invention.

Detailed ways

The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings: this embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following the described embodiment.

In the embodiment, the material of the thin metal plate used is 0.2 mm thick 316L stainless steel plate, the sealing material used is silicon rubber, and the filling material is fluororubber.

As shown in Figure 1, the fuel cell bipolar plate of the present invention comprises two completely identical gas flow field veneers, namely the oxidant flow field veneer 2 and the fuel gas flow field veneer 8, and the intercooler flow field veneer 5. Sealing gaskets 1, 4, 6 and 9 are placed in the frame sealing grooves of their corresponding flow field veneers. When assembling gas flow field veneers 2 and 8, fluorine rubber needs to be placed in filling areas 3 and 7 . Among them, the gas flow field veneers 2 and 8 can be punched out by one set of dies, and the coolant flow field veneer 5 can be punched out by another set of dies.

As shown in Figure 2, the middle area of the gas flow field veneer 2 is the reaction flow field 16, which adopts a serpentine flow field with ribs 17; one side of the gas flow field veneer 2 is sequentially provided with an oxidant inlet 10, Coolant inlet 11, fuel gas inlet 12; the other side is provided with oxidant outlet 13, coolant outlet 14, and fuel gas outlet 15 in sequence; Circular positioning holes 19 and 20 ; frame sealing groove 18 punched and formed on the gas flow field veneer 2 .

As shown in FIG. 3 , the three-dimensional schematic diagram of the gas flow field veneer 2 more clearly shows the structure of the flow field veneer, and the entire flow field veneer is surrounded by a groove sealing frame.

As shown in Figure 4, the middle area of the cooling liquid flow field veneer 5 is provided with a cooling liquid flow channel groove 21 in the middle of the cooling liquid flow field, which is configured with the liquid flow field groove 17 on the oxidant gas flow field veneer 2 form a liquid flow channel; on one side of the coolant flow field veneer 5, an oxidant inlet 10, a coolant inlet 11, and a fuel gas inlet 12 are sequentially arranged; the other side is sequentially arranged with an oxidant outlet 13, a coolant outlet 14, and a fuel gas outlet 15 ; Front frame sealing groove 23 on the coolant flow field veneer 5, and back frame sealing groove 22, positioning holes 19 and 20. The side where the gas flows is the front side.

As shown in FIG. 5 , it is a three-dimensional schematic view of the single plate in the coolant flow field, which more clearly shows the structure of the single plate.

As shown in Figure 6, it is a schematic diagram of the filling and leveling area on the back of the gas flow field veneer 2, wherein the blackened area 3 is the filling and leveling area; Figure 7 is a schematic diagram of the filling and leveling area on the back of the gas flow field veneer 8, where the blackened area is Area 7 is the filling area.

As shown in Figure 8, the cooling liquid channel formed between the gas flow field veneer 2 and the cooling liquid flow field veneer 5, the cooling liquid channel groove 21 on the cooling liquid veneer 2 and the oxidant gas veneer 1 The opposite liquid flow field grooves 17 are configured as coolant flow channel grooves.

As shown in Fig. 1, the bipolar plate of the present invention is composed of three flow field single plates 2, 5 and 8, sealing gaskets and filling materials. In the actual manufacturing process, three stamped metal flow field veneers are stacked together, and sealing materials are placed in the sealing groove to achieve the purpose of sealing, and they are pressed by external force so that there is no gap between the flow field veneers. Together, the bipolar plate of the present invention is formed.

As shown in Figures 2, 3 and 4, during work, the oxidant reaches the reaction area of the flow field veneer by the oxidant inlet 10 of the oxidant flow field veneer, on the other hand, the fuel gas is fed by the gas inlet of the fuel gas flow field veneer 12 reaches the reaction area of the flow field veneer, so that the oxidant and fuel gas contact with the electrolytic material and catalyst in the membrane electrode assembly, an electrochemical reaction occurs, electrons are generated, and an electric current is generated. The excess oxidant and fuel gas flow out from the oxidant outlet 13 and the fuel gas outlet 15 respectively, and at the same time, the cooling liquid enters the corresponding flow field single plate from the cooling liquid inlet 11 of the flow field veneer, and flows out from the cooling liquid outlet 14 to complete the cooling .

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (7)

1. the stamping forming fuel battery double plates of sheet metal, comprise two identical gas flowfield veneers and a middle flow field veneer, as oxidant stream field plate, fuel gas flow field plate and cooling fluid flow-field plate, it is characterized in that respectively:

Two gas flowfield veneers are by the encapsulant of placing in its surrounding contact-making surface, its frame seal groove, the contact-making surface of filling and leading up material and veneer both sides, middle flow field of filling and leading up placement in zone, connect respectively veneer both sides, described middle flow field, be combined into described fuel battery double plates; Be equipped with three imports and three outlets on each flow field veneer, be respectively: oxidant inlet, cooling liquid inlet, fuel gas inlets, oxidant outlet, cooling liquid outlet and fuel gas outlet;

One side of described gas flowfield veneer is the reactant gas flow zone, and the opposite side of described gas flowfield veneer is the liquid flow field groove corresponding to the spine of gas flow area;

In the middle of described, a side of flow field veneer is the flow-field channel that punching press forms, and with the liquid flow field groove of described gas flow field plate, is configured to cooling liquid flowing channel;

The flow field of the both sides of described oxidant stream field plate, described fuel gas flow field plate and described cooling fluid flow-field plate and the periphery of fluid inlet and outlet form seal groove and place encapsulant, and its degree of depth is identical with the degree of depth of described flow-field channel;

Need to fill and lead up the area filling rubber-like elastic material in described gas flowfield veneer groove frame, concordant with the contact-making surface of described flow field veneer;

Described gas flowfield veneer and described middle flow field veneer are that the outer tightening seal material of defeating is fitted in aggregates and realizes sealing, to form described fuel battery double plates.

2. the stamping forming fuel battery double plates of sheet metal as claimed in claim 1, wherein said flow-field channel, its width is 0.5-2m, the degree of depth is 0.2-0.5mm; Described seal groove, its width is 1-4mm, the degree of depth is 0.2-0.5mm.

3. the stamping forming fuel battery double plates of sheet metal as claimed in claim 1, wherein at described flow field veneer, the centre position of the both sides parallel with the flow-field channel length direction is provided with circular location hole;

Described oxidant inlet, described cooling liquid inlet and described fuel gas inlets, and described oxidant outlet, described cooling liquid outlet and the outlet of described fuel gas set gradually, and import and the relative both sides that export at described flow field veneer.

4. the stamping forming fuel battery double plates of sheet metal as described as one of claim 1-3, wherein said encapsulant is gasket seal, is placed in seal groove.

5. the stamping forming fuel battery double plates of sheet metal as described as one of claim 1-3, the thickness of wherein said sheet metal is 0.1mm-0.3mm, and the material of described gas flowfield veneer and middle flow field veneer is selected from one of stainless steel, titanium and titanium alloy metallic sheet stock.

6. the application of the stamping forming fuel battery double plates of the described sheet metal of one of claim 1-5 in Proton Exchange Membrane Fuel Cells, direct methanol fuel cell, proton exchange membrane water electrolyzer device and regenerative fuel cell.

7. a proton exchanging film fuel battery, is characterized in that, comprises the stamping forming fuel battery double plates of the described sheet metal of one of claim 1-5.

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