KR20110019586A - Fuel cells sharing anode flowfield and fuel cell power generation apparatus - Google Patents

Abstract

PURPOSE: A fuel cell is provided to enable reaction of flow of fuel electrode plate with oxygen in both sides of fuel electrode plate and to largely improve output. CONSTITUTION: A fuel cell comprises: a fuel electrode plate(60) having flow channel; a pair of membrane-electrode assemblies(10) which is attached on both sides of the fuel electrode plate and has an electrolyte and electrode; and a pair of air electrode plate(50) which is attached on the other side of the membrane-electrode assemblies and is able to contact the membrane electrode assemblies. The flow channel is formed in a silt structure.

Description

Fuel cell sharing hydrogen flow path and fuel cell power generation device having same {Fuel Cells Sharing Anode Flowfield and Fuel Cell Power Generation Apparatus}

The present invention relates to a fuel cell and a fuel cell generator having the same. More specifically, the present invention relates to a fuel cell including a fuel cell plate including one anode plate and two cathode plates, and a fuel cell power generation apparatus including the same.

In general, a fuel cell generator is a generator that generates electricity by electrochemically reacting a hydrogen-containing fuel such as methanol and an oxidant gas such as air at a gas diffusion electrode. This is in the spotlight as a future clean energy source to solve the difficulty of securing power due to the increase of electric power demand and the global environmental problem caused by the use of fossil energy.

1 is a schematic diagram showing the structure of a fuel cell stack in general. Since the voltage of the unit cell is low, in order to increase the total voltage, the fuel cell generator generally has a stack in which a plurality of unit cells for generating electricity are stacked. The unit cell is located at both sides of the membrane electrode assembly 10 (MEA) and the cathode electrode (anode) and the cathode (cathode, cathode) provided on both sides of the electrolyte membrane, respectively, and the channel for fluid flow The anode plate 160 and the cathode plate 150 are formed. The anode plate 160 and the cathode plate 150 supply hydrogen-containing fuel and oxygen-containing air to the anode and the cathode, respectively, and discharge carbon dioxide, water, and fuel and air that do not participate in the reaction, respectively, from the anode and the cathode. Act to make it work. Meanwhile, the unit cells are provided with current collectors 130 and 140 for collecting current generated from the membrane electrode assembly 110. The current collectors 130 and 140 are provided to reinforce the brittleness of the plate when the bolt and nut are fastened as well as a function of collecting electricity.

Here, a flow path is formed in the anode plate 160 so that fuel (or hydrogen) flowing through the flow path reacts with air (or oxygen) supplied to the cathode plate 150 to generate electricity. Excess fuel is injected for smooth discharge of the product, and fuel flowing in the flow path reacts with oxygen only on one side of the anode plate 160, so that a large number of fuels do not react with oxygen and only flow through the flow path. Phenomenon occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel cell and a fuel cell power generation apparatus including the fuel cell capable of reacting oxygen on both sides of the fuel flowing through the flow path of the anode plate so that two cathode plates are in contact with both surfaces of one anode plate. It is.

According to an aspect of the present invention, the present invention, a fuel electrode plate having a flow path through which the fuel flows, a pair of membrane electrode assembly attached to both sides of the anode plate and having an electrolyte membrane and an electrode, Provided is a fuel cell comprising a pair of cathode plates attached to the other side of the pair of membrane electrode assemblies and allowing external air to contact the membrane electrode assembly.

The flow path may have a slit structure penetrating the anode plate. Alternatively, the flow path may have a structure in which flowing fuel reacts on both sides of the anode plate.

The fuel cell according to the present invention may further include a cathode current collector formed between the membrane electrode assembly and the cathode plate, and a cathode current collector respectively formed between the membrane electrode assembly and the anode plate. The cathode current collector and the anode current collector may each include an insulating film, a conductive adhesive layer interposed between the insulating film and the membrane electrode assembly, and a metal pad interposed between the insulating film and the conductive adhesive layer. Each of the electrodes may include a plurality of unit electrodes, and the metal pad may include a plurality of unit metal pads corresponding to the shape of the unit electrode. The unit metal pad may include a terminal protruding outward from the cathode current collector and the anode current collector, and at least one of the terminals may be disposed adjacent to a corresponding unit metal pad with the membrane electrode assembly therebetween. Can be connected to the terminal.

Meanwhile, a plurality of openings may be formed in the cathode current collector and the anode current collector. The cathode plate may have an air hole through which air may pass, an opening of the cathode current collector may have a shape corresponding to the air hole, and an opening of the anode collector may have a shape corresponding to the flow path.

According to another aspect of the invention, the present invention, the fuel cell including the fuel cell described above, a fuel supply unit for supplying a fuel containing hydrogen to the fuel cell, and an air supply unit for supplying air to the fuel cell Provides a power generation device. The fuel supply unit may include a metal hydride cartridge having a hydrogen storage alloy.

According to the fuel cell according to the present invention, two cathode plates are in contact with both surfaces of one anode plate, so that fuel flowing through the flow path of the anode plate can react with oxygen at both sides, thereby increasing the volume of the fuel cell. The fuel cell output is greatly improved without increasing it.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that detailed descriptions of related well-known technologies or functions may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, exemplary embodiments of a fuel cell and a fuel cell power generation apparatus including the same according to the present invention will be described in detail with reference to the accompanying drawings. And duplicate description thereof will be omitted.

2 is a schematic view showing the structure of a fuel cell according to an embodiment of the present invention. A fuel cell according to an embodiment of the present invention includes a fuel electrode plate 60 having a flow path through which fuel flows, and a pair of membrane electrode assemblies attached to both surfaces thereof and having an electrolyte membrane, a fuel electrode, and an air electrode. 10), a pair of cathode plates 50 in contact with the other surface of the membrane electrode assembly 10, and a cathode current collector 30 and an anode current collector 40, respectively.

3 is an exploded view showing the structure of a fuel cell according to an embodiment of the present invention. Referring to FIG. 3, the membrane electrode assembly 10, the gasket 20, the current collectors 30 and 40, and the plates 50 and 60 are illustrated.

The gasket 20, the cathode current collector 30, the anode current collector 40, the cathode plate 50, and the anode plate 60 are sequentially positioned on both sides of the membrane electrode assembly 10. The membrane electrode assembly 10 substantially generates electricity using fuel, and the gasket 20 serves to prevent leakage of fuel and air, and the current collectors 30 and 40 are disposed in the membrane electrode assembly 10. It serves to collect the generated electricity. Plates 50 and 60 are pressurized inward to complete the stacking structure of the fuel cell.

Two cathode plates 50 are in contact with both surfaces of one anode plate 60 so that fuel flowing through the flow path of the anode plate 60 can react with oxygen supplied through the cathode plate 50 from both sides. Thus, the output and efficiency of the fuel cell are greatly improved without significantly increasing the volume of the fuel cell. That is, the maximum power (W), the power per unit area (W / Cm 2) or the power per unit volume (W / cc) and the like can be increased compared to the case of one cathode plate.

Detailed description of each component will be described below with reference to FIGS. 4 to 9.

4 is a plan view illustrating a structure of a membrane electrode assembly 10 in a fuel cell according to an embodiment of the present invention, and FIG. 5 is a membrane electrode assembly in a fuel cell according to an embodiment of the present invention. It is a side view which shows the structure of 10). 4 and 5, an electrolyte membrane 12, unit electrodes 14 and 16, and a unit cell 18 are illustrated in the membrane electrode assembly 10. Membrane Electrode Assembly (MEA) 10 serves to substantially generate electricity by reacting fuel with a catalyst, and on both sides of the electrolyte membrane 12 and the electrolyte layer having selective hydrogen ion permeation characteristics. A pair of unit electrodes provided, i.e., a fuel electrode (anode, anode) 16 and an air electrode (reduction electrode, cathode, cathode) 14 are provided.

Taking the example of a polymer electrolyte fuel cell (PEMFC) fuel cell using hydrogen as a fuel, the chemical reaction occurring at each electrode is described as follows.

<Reaction Scheme 1> ^{_{anode: H 2 → 2H + + 2e}} -

<Reaction formula 2> air _{electrode: (1/2) O 2 + 2H} + + 2e - → H 2 O

Scheme 3 Total Reaction: H ₂ + (1/2) O ₂ → H ₂ O

Electricity is generated through the above reaction, and water is generated in the air electrode 14. As described above, the above chemical reaction is an example of a reaction occurring in the case of a solid oxide fuel cell using hydrogen as a fuel, and the chemical reaction occurring at each electrode may vary depending on the type of fuel cell. to be.

As shown in FIGS. 4 and 5, the unit cell 18 including the fuel electrode 16, the air electrode 14, and the electrolyte membrane 12 may serve as an independent battery. In a flat fuel cell, one plane is divided into several unit cells 18, and each unit cell 18 is connected in series to increase the potential difference of the entire fuel cell. The structure of the unit cell 18 affects the overall stack structure, and according to the shape of the unit cell 18 as shown in FIG. 3, the current collectors 30 and 40, the gasket 20, and the plate 50, 60) is determined.

Next, FIG. 6 is a plan view illustrating a cathode current collector 30 or an anode current collector 40 in a fuel cell according to an embodiment of the present invention, and FIG. 7 is a fuel cell according to an embodiment of the present invention. In the figure, it is a side view showing the structure of the cathode current collector 30 or the anode current collector 40. 6 and 7, the current collectors 30 and 40 have insulating films 32 and 42, metal pads 34 and 44, terminals 35 and 45, conductive adhesive layers 36 and 46, and openings ( 38, 48 are shown.

The current collectors 30 and 40 are devices for collecting electrical energy generated by the membrane electrode assembly 10, and are coupled to each of the unit electrodes 14 and 16 of the membrane electrode assembly 10 to form a stacked structure.

The current collectors 30 and 40 have a layered structure as shown in FIG. 6, and the metal pads 34 and 44 are coated with the insulating films 32 and 42 as a base layer, and the conductive adhesive layers 36 and 46 thereon. ) Is formed.

The insulating films 32 and 42 may be made of an electrically conductive material such as a polymer and may be a flexible material. For example, a polymer film having a high chemical resistance and relatively high heat resistance, such as polyimide, may be used. have.

The conductive adhesive layers 36 and 46 may be formed by applying a conductive adhesive in which metal powder or metal wire is mixed with an adhesive epoxy. The metal powder or the metal wire may include nickel (Ni) or silver (Ag), and may be combined with the epoxy in various ratios in consideration of adhesion and electrical conductivity.

Since the current may flow only by the conductive adhesive layers 36 and 46 itself, it may function as the current collectors 30 and 40, but as illustrated in FIG. 5 for more reliable implementation of the current collectors 30 and 40. As such, the metal pads 34 and 44 having high electrical conductivity may be formed on the insulating films 32 and 42, and the conductive adhesive layers 36 and 46 may be formed thereon.

The metal pads 34 and 44 may be formed by coating a material having high electrical conductivity such as gold (Au). The metal pads 34 and 44 may be configured of a plurality of unit metal pads 31 and 41 as shown in the drawing. The unit metal pads 31 and 41 are partitioned between insulating films 32 and 42.

Terminals 35 and 45 connecting between the unit metal pads 31 and 41 may be formed to protrude. When the anode current collector 30 and the cathode current collector 40 are laminated to face each other via the membrane electrode assembly 10, each of the terminals 35 of the unit metal pad 31 on the cathode side includes a unit cell together with the corresponding cathode. 18 and overlapping with the terminal 45 of the unit metal pad 41 adjacent to the anode side of the fuel electrode instead of the corresponding anode, and are connected in series between the neighboring unit cells 18. However, one of the terminals 35 and 45 is connected to an external circuit so that the current does not overlap with the other terminal.

The cathode current collector 30 may have an opening 38 so as to supply air to the membrane electrode assembly 10. Since the size and shape of the opening 38 is related to the size of the air hole 58 of the cathode plate 50, it will be described in detail in the cathode plate 50 to be described later.

The anode current collector 40 must have an opening 48 formed therein to supply hydrogen as fuel to the membrane electrode assembly 10. Since the size and shape of the opening 48 is related to the shape of the flow path 68 of the anode plate 60, it will be described in detail later in the anode plate 60.

Next, FIG. 8 is a plan view showing the cathode plate 50 in the fuel cell according to an embodiment of the present invention, and FIG. 9 is a view showing the anode plate 60 in the fuel cell according to the embodiment of the present invention. It is the top view shown.

Plates 50 and 60 are pressed outside the current collectors 30 and 40, that is, at the outermost portion of the stack structure at a proper pressure to the stack structure of the stack, so that the warpage should be small, and electrical shorts are prevented. It can be insulated to make it. Accordingly, the plates 50 and 60 may use a light metal such as aluminum, but may form an oxide film or may be electrically insulated by Teflon coating to prevent a short.

Referring to FIG. 8, an air hole 58 formed in the cathode plate 50 is illustrated. Since oxygen is required in the membrane electrode assembly, a method of using an artificial pump to inject air into the cathode to provide oxygen has a problem that the volume of the fuel cell becomes large and noise occurs.

In the flat stack structure, an appropriate air hole 58 is formed so that air in the air can be injected to supply oxygen. Since the air hole 58 serves to provide air in the atmosphere to the air electrode, it is necessary to form the air hole 58 in an appropriate shape and opening ratio. The aperture ratio means the size of the air hole 58 to the size of the air electrode 14 of the membrane electrode assembly. In addition, as illustrated in FIG. 6, the opening 38 of the cathode current collector 30 may also be formed to correspond to the shape and size of the air hole 58.

Referring to FIG. 9, the anode plate 60 may have a flow path 68 such as a serpentine-shaped slit. The serpentine shape means a shape that is twisted and twisted as shown in the figure. When the flow path 68 of the serpentine-shaped slit is used, the fuel supplied through the fuel supply port 64 can be uniformly supplied to each of the unit cells 18.

Since the fuel moves along the flow path 68, the opening 48 of the anode current collector 40 may be formed at a position corresponding thereto. The opening 48 may have a serpentine shape, such as the flow path 68. However, since the cathode current collector 40 formed of a flexible material has a problem of fixing, as shown in FIG. 8. It is also possible to form several long openings 48 in parallel, without forming an opening part.

Next, the gasket 20 is not an essential component in the stack structure, but may be interposed between the membrane electrode assembly 10 and the current collectors 30 and 40 for efficient electricity generation. have.

Since the gasket 20 serves to seal the fuel or air from leaking in the fuel cell, a material having elasticity, such as Teflon and PFA (perfluoroalkoxy), has good chemical resistance and elasticity. Do. The gasket 20 has a shape where the metal pads of the current collectors 30 and 40 are not formed (see FIG. 2) so that the gasket 20 may be covered by the gasket 20. Can be prevented.

2 to 9, each layer structure of the stack according to an embodiment of the present invention has been described. Air enters through the air hole 58 of the cathode plate 50 and oxygen is supplied to the cathode, and the fuel injected through the fuel supply port 64 of the anode plate 60 moves along the flow path 68. Hydrogen is supplied to the fuel electrode, and electrical energy is produced in the electrode membrane assembly 10. The generated electrical energy may be collected through the current collectors 30 and 40, and the moved hydrogen is discharged through the fuel outlet 66.

By using the stack described above, it is possible to provide a fuel cell generator having the same. 10 is a schematic diagram of a fuel cell generator according to an embodiment of the present invention. The fuel supply unit 200 supplies a fuel including hydrogen to the fuel cell 100, and the air supply unit 300 serves to supply oxygen to the fuel cell 100. Since the structure of the fuel cell 100 used in the fuel cell generator is the same as described above, a detailed description thereof will be omitted.

The fuel supply unit 200 supplies hydrogen, which is a fuel of the fuel cell, and may directly supply hydrogen, such as a tank storage tank, but may be a hydrogen generator. The hydrogen generator includes an electrode having different ionization tendencies and an aqueous electrolyte solution, and generates hydrogen from water using electrons obtained through oxidation of a metal. The hydrogen generator includes a metal hydride cartridge including a hydrogen storage alloy and can be miniaturized.

Since the air supply unit 300 supplies oxygen to the fuel cell, a pump for injecting air into the stack may be used. However, the air supply unit 300 may be any configuration in which air is supplied without a separate structure, and may be omitted extremely. In this embodiment, even if there is no separate air supply device, since oxygen may be supplied using natural convection, it may be omitted.

As mentioned above, although specific embodiment of this invention was described, this is only an illustration and this invention is not limited to this, It should be interpreted that it has the broadest range based on the basic idea disclosed in this specification. Those skilled in the art can change the material, size, etc. of each component according to the application field, it is possible to implement a pattern of the shape not shown by combining or replacing the disclosed embodiments, but this is also not departing from the scope of the present invention. In addition, those skilled in the art can easily change or modify the disclosed embodiments based on the present specification, it is apparent that such changes or modifications are included in the scope of the present invention.

1 is a schematic diagram showing the structure of a fuel cell as a general warfare.

2 is a schematic view showing the structure of a fuel cell according to an embodiment of the present invention.

3 is an exploded view showing the structure of a fuel cell according to an embodiment of the present invention.

4 is a plan view showing the structure of the membrane electrode assembly 10 in the fuel cell according to the embodiment of the present invention;

FIG. 5 is a side view showing the structure of the membrane electrode assembly 10 in the fuel cell according to the embodiment of the present invention.

6 is a plan view illustrating a cathode current collector 30 or a cathode current collector 40 in a fuel cell according to an exemplary embodiment of the present invention.

7 is a side view illustrating the structure of the cathode current collector 30 or the anode current collector 40 in the fuel cell according to the exemplary embodiment of the present invention.

8 is a plan view showing a cathode plate 50 in the fuel cell according to an embodiment of the present invention.

9 is a plan view of the anode plate 60 in the fuel cell according to the exemplary embodiment of the present invention.

10 is a schematic diagram of a fuel cell generator according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: membrane electrode assembly 12: electrolyte membrane

14, 16: unit electrode 18: unit cell

20: gasket

30: air cathode current collector 31, 41: unit metal pad

32, 42: insulating film 34, 44: metal pad

35, 45: terminals 36, 46: conductive adhesive layer

38 and 48: opening 40: fuel electrode current collector

50: air electrode plate 58: air hole

60: anode plate 64: fuel supply port

66: fuel outlet 68: euro

100: fuel cell

200: fuel supply unit 300: air supply unit

Claims (12)

An anode plate having a flow path through which fuel flows; A pair of membrane electrode assemblies attached to both surfaces of the anode plate and having an electrolyte membrane and an electrode; A pair of cathode plates attached to the other side of the pair of membrane electrode assemblies and allowing external air to contact the membrane electrode assembly; Fuel cell comprising. The method of claim 1, The flow path is a fuel cell formed of a slit structure penetrating the anode plate. The method of claim 1, The flow path is a fuel cell capable of reacting the flowing fuel on both sides of the anode plate. The method according to any one of claims 1 to 3, A cathode current collector formed between the membrane electrode assembly and the cathode plate, and The anode current collector formed between the membrane electrode assembly and the anode plate, respectively Fuel cell further comprising. The method of claim 4, wherein The cathode current collector and the anode current collector, respectively, Dielectric film, A conductive adhesive layer interposed between the insulating film and the membrane electrode assembly, and A metal pad interposed between the insulating film and the conductive adhesive layer Fuel cell comprising. The method of claim 5, The electrode is composed of a plurality of unit electrodes, respectively The metal pad is composed of a plurality of unit metal pads corresponding to the shape of the unit electrode. The method of claim 6, The unit metal pad is provided with a terminal protruding outward from the cathode current collector and the anode current collector, At least one of the terminals is connected to a terminal of a unit metal pad adjacent to a corresponding unit metal pad with the membrane electrode assembly interposed therebetween. The method of claim 4, wherein And a plurality of openings are formed in the cathode current collector and the anode current collector. The method of claim 8, The cathode plate is formed with an air hole through which air can pass, The opening of the cathode current collector has a shape corresponding to the air hole, An opening of the anode current collector corresponding to the flow path; The method of claim 4, wherein And a gasket interposed between the cathode current collector and the membrane electrode assembly and between the anode current collector and the membrane electrode assembly to seal therebetween. A fuel cell according to any one of claims 1 to 3, A fuel supply unit supplying a fuel including hydrogen to the fuel cell; Air supply unit for supplying air to the fuel cell Fuel cell power generation device comprising. The method of claim 11, The fuel supply unit includes a fuel cell generator including a metal hydride cartridge having a hydrogen storage alloy.

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