KR20060033521A - Fuel cell stack assembly - Google Patents

Abstract

The present invention relates to a fuel cell stack assembly in which a teflon tube is inserted into a hydrogen, air, and cooling water pipe line in a fuel cell stack, which is excellent in corrosion resistance and can reduce manufacturing costs, and includes a membrane-electrode assembly (MEA) and a gasket. In a polymer electrolyte fuel cell stack having a structure in which a plurality of unit cells each having a separator as a base unit are stacked over hundreds, and a current collector plate and an end plate are placed on both sides, and fastened using tie rods or bands, respectively, Furnace, by inserting the anticorrosive tube excellent in corrosion resistance in the air pipe and the cooling water pipe, characterized in that to form a double pipe.

According to the present invention, the corrosion resistance of the fuel cell stack is greatly improved and can be used semipermanently.

Fuel cell stack, gas pipe, anticorrosive tube, double pipe, Teflon pipe

Description

Assembly of a Fuel Cell Stack

1 is a cross-sectional view showing a conventional fuel cell stack assembly;

2 is a cross-sectional view illustrating a fuel cell stack assembly according to the present invention.

  <Description of Symbols for Main Parts of Drawings>

10: fuel cell stack 11: anode

12: air electrode 13: polymer electrolyte membrane

14: air channel 15: hydrogen channel

20: Separator 22: Cooling water flow path

24: gasket 26: current collector

30: end plate 32: air line

34: cooling water pipe 36: hydrogen pipe

33, 35, 37: Packing member 42, 44, 46: Teflon tube

The present invention relates to a fuel cell stack assembly, and more particularly, to a fuel cell stack, by inserting a teflon tube into a hydrogen pipe, an air pipe, and a cooling water pipe, a fuel cell having excellent corrosion resistance and a reduced manufacturing cost. Relates to a stack assembly.

Unlike conventional internal combustion engine cars, which are driven by exploding fossil fuel and oxygen in the air in the engine, converting the chemical energy of the fossil fuel into mechanical energy, the fuel cell vehicle serves as the engine of the conventional internal combustion engine. Hydrogen and oxygen in the air are supplied to the battery stack to convert electrical energy generated into mechanical energy to drive a car.

In recent years, fuel cells have higher efficiency and lower pollution emissions than internal combustion engines, and thus have been spotlighted as promising alternative means for replacing conventional internal combustion engines.

In particular, a fuel cell stack using an electrolyte membrane, as shown in FIG. 1, has a polymer electrolyte membrane 13 for selectively transporting hydrogen ions and a pair of electrodes formed on both surfaces of the polymer electrolyte membrane 13, that is, a fuel electrode. (11) and the air electrode (12).

The positive electrode is usually composed of a carbon powder carrying a platinum group metal catalyst as a main component, a catalyst layer formed on the surface of the polymer electrolyte membrane 13, and a diffusion layer formed on the outer surface of the catalyst layer and having both breathability and electron conductivity ( diffusionlayer).

In addition, a gasket 24 is disposed around the electrode with a polymer electrolyte membrane interposed therebetween so that the fuel gas and the oxidant gas supplied to the electrode are not leaked to the outside or the two kinds of gases are not mixed with each other. The gasket 24 is generally a rubber or elastomeric polymer having high chemical resistance such as EPDM rubber, silicone elastomer, fluoroelastomer and the like.

The gasket 24 is assembled in advance with the electrode and the polymer electrolyte membrane. This is called MEA (electrolyte film-electrode assembly). On the outer side of the MEA, a conductive separator plate 20 for mechanically fixing this and electrically connecting adjacent MEAs in series with each other and in parallel in some cases is disposed. The air flow passage 14 and the hydrogen flow passage 15 for supplying the reaction gas to the electrode surface and transporting the generated gas or the surplus gas are formed in the portion in contact with the MEA of the separation plate 20.

The air channel 14 and the hydrogen channel 15 may be installed separately from the separator 20, but a groove is formed on the surface of the separator 20 so that the groove is a gas channel.

In addition, in order to supply hydrogen gas and air to these grooves, a hydrogen pipeline 36 and an air pipeline 32 are provided separately. That is, by making a through hole in the separator plate 20 forming the gas flow path so that the hydrogen pipe 36 and the air pipe 32 are connected to the hydrogen flow path 15 and the air flow path 14 in contact with the anode, Hydrogen gas and air are directly supplied to the fuel electrode 11 and the air electrode 12 of the fuel cell.

Once again, the polymer electrolyte fuel cell (PEMFC) stack 10, which is a power source of a fuel cell vehicle, includes an electrolyte membrane-electrode assembly (MEA), a gasket 24, and a separator plate. Hundreds of cells are alternately stacked on the basis of (20) as base units, and current collectors 26 and end plates 30 are placed on both sides, and then tie rods or metal bands ( band).

In the case of the polymer electrolyte fuel cell stack, humidified hydrogen, air, and cooling water are supplied into the stack to operate at a temperature ranging from room temperature to 90 °, pressure from atmospheric pressure to 5 bar, and voltage from 0.5 to 0.9 V / cell. .

Looking at each of the components of the fuel cell stack in detail, first, the electrolyte membrane-electrode assembly has a structure in which two electrodes, the anode and the cathode, are bonded to both sides of the polymer electrolyte membrane, and the hydrogen and the humidified hydrogen in the anode and the cathode, respectively, It supplies air to generate electricity, water and heat by oxidation of hydrogen and reduction of oxygen.

Secondly, the gasket serves to maintain the airtightness of hydrogen, air and cooling water supplied to the anode and the cathode, respectively, and is used in the form of a plate or O-ring as a silicon material.

Thirdly, the separator serves to supply a humidified reactor to the electrolyte membrane-electrode assembly, drain the generated water, and transport electrons generated during the electrochemical reaction from the anode to the cathode.

Conventional polymer electrolyte fuel cell (PEMFC) stacks consist of hundreds or more of alternating single cells based on membrane-electrode assemblies (MEAs), gaskets, and separators, and the current collector plate and end plate on each side, and then tie rods or It was designed to be simply fastened using a band or the like.

The polymer electrolyte fuel cell stack generally supplies humidified hydrogen, air, and coolant into the stack to operate at temperatures above room temperature and pressure above atmospheric pressure. This condition is the current collector plate and the end of the metal electrolyte fuel cell stack. Corrosion resistance treatment, that is, gold plating or anodizing treatment, must be performed because it provides severe electrochemical corrosion conditions for the plate, which causes an increase in the manufacturing process and an increase in the manufacturing cost and makes it impossible to use semi-permanently. .

Accordingly, the present invention has been made to solve the above problems, by inserting the Teflon tube into the hydrogen pipe, the air pipe and the cooling water pipe inside the fuel cell stack fuel excellent corrosion resistance and manufacturing cost can be reduced It is an object to provide a battery stack assembly.

In order to achieve the above object, the present invention, after stacking hundreds or more of alternating unit cells based on the membrane-electrode assembly (MEA), gaskets, separator plates and the current collector plate and end plate on each side, tie rod or A polymer electrolyte fuel cell stack having a structure fastened by using a band or the like, characterized in that a double pipe is formed by inserting an anticorrosive tube having excellent corrosion resistance into a hydrogen pipe, an air pipe, and a cooling water pipe.

Another feature of the present invention is that the Teflon-based polymer tube is used as the anticorrosion tube having excellent corrosion resistance, and the Teflon tube is fixed to the end plate by an O-ring.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a cross-sectional view of a fuel cell stack assembly according to the present invention, some of which are referred to by reference numerals used in the description of the prior art.

The fuel cell stack assembly according to the present invention includes a hydrogen conduit 36, an air conduit 32, and a cooling water conduit formed through a through hole in the separator 20 to supply hydrogen gas and air directly to the anode of the fuel cell. Teflon tubes 42, 44 and 46 are inserted into 34 and the Teflon tubes 42, 44 and 46 are fixed to the end plate 30 by O-rings.

First, the assembling structure of the polymer electrolyte fuel cell (PEMFC) stack will be described. A polymer electrolyte membrane 13 is sandwiched between the anode 11 and the cathode 12 to fix the electrolyte membrane. A gasket 24 is disposed. The gasket 24 is generally made of rubber or elastomer having high chemical resistance such as EPDM rubber, silicone elastomer, fluoroelastomer and the like.

The gasket 24 is assembled in advance with the electrodes 11 and 12 and the polymer electrolyte membrane 13, which is called an electrolyte membrane-electrode assembly, and the electrolyte membrane-electrode assembly is a conductive separator plate. Mechanically fixed by the 20 and the gasket 24, the air passage 14 and the hydrogen passage 15 for transporting the hydrogen and air supplied to the surface of the separation plate 20 is formed.

As described above, hundreds of alternating single cells based on an electrolyte membrane-electrode assembly (MEA: Membrane Electrode Assembly), a gasket, and a separator as a basic unit are alternately stacked, and a current collector 26 is provided on both sides. After the end plate 30 is placed, the hydrogen pipe 36, the air pipe 32, and the cooling water pipe (from the separation plate 20 to the end plate 30 through the current collector plate 26) A double pipe is formed by inserting an anticorrosive tube having excellent corrosion resistance into the inlet and outlet pipe of 34).

As a specific embodiment using the above-described anticorrosive tube, Teflon tubes 42, 44, and 46, which are Teflon-based polymer tubes, may be inserted into the gas and cooling water pipes 34, respectively.

Subsequently, the Teflon tubes 42, 44, and 46, which are the tubes for the anticorrosion, are fixed to the end plate 30 with an O-ring, and then fuel is fixed by using a tie rod or a metal band. Assemble and fasten the battery stack.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make modifications without departing from the essential characteristics of the present invention. Therefore, the technical idea of the present invention is not limited to the above embodiment.

The fuel cell stack assembly according to the present invention has a structure in which the hydrogen gas, air, and coolant are directly supplied through a Teflon tube while preventing the humidified hydrogen gas, air, and coolant from directly contacting the metal current collector plate and end plate. Since supplied to the separator plate and discharged to the outside from the separator plate, the corrosion resistance of the fuel cell stack is greatly improved and can be used semi-permanently.

Claims (3)

Stacked hundreds or more of alternating single cells based on membrane-electrode assembly (MEA), gasket, and separator plate, polymer plates and end plates on both sides, and then fastened by tie rods or bands In the electrolyte fuel cell stack, A fuel cell stack assembly comprising inserting an anticorrosion tube having excellent corrosion resistance into a hydrogen pipe, an air pipe, and a cooling water pipe to form a double pipe. The method of claim 1, The anticorrosive tube for corrosion resistance is a fuel cell stack assembly, characterized in that using a Teflon-based polymer tube. The method of claim 1, The anticorrosive tube is a fuel cell stack assembly, characterized in that fixed to the end plate by the O-ring.

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