KR20080076367A - Multi cell supporting device - Google Patents

Abstract

A multi cell supporting device is provided to simplify the test and activation process for many membrane-electrode assemblies and reduce a process time when the supporting device is applied to a membrane-electrode assembly tester or activation apparatus. A multi cell supporting device include: a first multi cell union plate(20) having a fuel supply structure; a second multi cell union plate(30) having an air supply structure; and fluid pressure presses(40,50) which compress the first multi cell plate and the second multi cell plate so as to apply uniform compressive force to respective membrane-electrode assemblies while many membrane-electrode assemblies are supported between the first multi cell plate and the second multi cell plate.

Description

Multi Cell Supporting Device

1 is a cross-sectional view showing a structure of a MEA of a general fuel cell.

2 is a cross-sectional view showing a state in which a multi-cell support device binds a plurality of MEAs according to an embodiment of the present invention.

3A through 3C are plan views illustrating one embodiment of the first multi-cell binding plate of FIG.

4 is a plan view showing an embodiment of the second multi-cell binding plate of FIG.

Figure 5 is a block diagram showing the structure of a MEA test / activation device implemented using a multi-cell support device according to an embodiment of the present invention.

The present invention is intended to be used in a test apparatus or a pretreatment apparatus for a membrane electrode assembly constituting a fuel cell, and in particular, a test apparatus or liquid capable of performing a test or pretreatment at a time on a plurality of membrane electrode assemblies. It relates to a multi-cell support device that can be applied to the Tibet device.

In general, a fuel cell is a power generation system that converts chemical energy directly into electrical energy by an electrochemical reaction between hydrogen and oxygen. The hydrogen may supply pure hydrogen directly to the fuel cell system, or may supply hydrogen by reforming materials such as methanol, ethanol, natural gas, and the like. The oxygen may directly supply pure oxygen to the fuel cell system, or may supply oxygen included in normal air using an air pump or the like.

The fuel cell is a polymer electrolyte type and direct methanol type fuel cell operating at room temperature or below 100 ° C, a phosphoric acid type fuel cell operating at around 150 to 200 ° C, a molten carbonate type fuel cell operating at a high temperature of 600 to 700 ° C, 1000 It is classified into the solid oxide fuel cell etc. which operate at high temperature more than degreeC. Each of these fuel cells is basically the same operating principle of generating electricity, but different fuel types, catalysts, electrolytes and the like used.

The direct methanol fuel cell (DMFC) of the fuel cell is used as a direct fuel after mixing a high concentration of liquid methanol with water instead of hydrogen as a fuel. The direct methanol fuel cell has a lower power density than the fuel cell using hydrogen as a direct fuel. However, the methanol has a high energy density per volume and is easy to store, which is advantageous in situations where low power and long operation are required. have. In addition, it is very advantageous for miniaturization because additional equipment such as a reformer for reforming fuel to generate hydrogen is unnecessary.

In addition, the direct methanol fuel cell includes an electrolyte membrane and an electrode-electrolyte assembly (MEA) including an anode electrode and a cathode electrode in contact with both surfaces of the electrolyte membrane. Fluorinated polymers are used as electrolyte membranes. Fluorinated polymers penetrate methanol too rapidly and crossover occurs when unreacted methanol penetrates electrolyte membranes when methanol is used as a fuel. Is generated. Therefore, in order to lower the concentration of methanol, a fuel mixed with methanol and water is supplied to the fuel cell system.

On the other hand, Polymer Electrolyte Membrane Fuel Cell (PEMFC) uses hydrogen generated by reforming materials such as methanol, ethanol and natural gas. Quick start and response characteristics. Therefore, as a mobile power source such as a car, as well as a distributed power source such as a house or a public building, and a power source for a small mobile device such as a portable electronic device, there is a wide range of applications.

Meanwhile, the polymer electrolyte fuel cell not only converts the reformed gas rich in hydrogen necessary for generation of electricity through catalytic reactions such as steam reforming (SR) and water gas shift (WGS), but also reformed gas. It is included in the removal of carbon monoxide poisoning the catalyst of the fuel cell. Since the catalytic reaction requires water, the fuel introduced into the reformer is mixed with water and supplied as a mixed fuel.

The unit power generation element of the fuel cell is a membrane electrode assembly (MEA), wherein the membrane electrode assembly is an anode electrode (also called a "fuel electrode" or an "oxide electrode") and a cathode on both sides of an electrolyte membrane capable of permeating hydrogen ions. It has a structure in which an electrode (also called "air electrode" or "reduction electrode") is formed.

The anode generates hydrogen ions (H +) and electrons (e−) by oxidizing the hydrogen gas generated by reforming the hydrogen-containing fuel supplied from the outside. The cathode electrode converts oxygen in air supplied as an oxidant into oxygen ions and electrons. In addition, the hydrogen ions generated from the polymer membrane anode electrode are ionically exchanged to the cathode electrode and have a thickness of about 50 to 200 μm as a conductive polymer electrolyte membrane having a function of preventing permeation of hydrogen-containing fuel.

Referring to FIG. 1, the membrane electrode assembly 20 includes a polymer electrolyte membrane 12, an anode catalyst layer 14, and a cathode catalyst layer 16. When the hydrogen gas or the fuel containing hydrogen is supplied to the anode catalyst layer 14 in the fuel cell 10, an electrochemical oxidation reaction occurs in the anode catalyst layer 14 and ionized with hydrogen ions (H ⁺ ) and electrons (e ⁻ ). And oxidize. Ionized hydrogen ions move from the anode catalyst layer 14 through the polymer electrolyte membrane 12 to the cathode catalyst layer 16, and electrons move from the anode catalyst layer 14 through the external wire 18 to the cathode catalyst layer 16. Done. The hydrogen ions transferred to the cathode catalyst layer 16 cause an electrochemical reduction reaction with oxygen supplied to the cathode catalyst layer 16 to generate heat of reaction and water. And electric energy is generated by the movement of electrons.

The electrochemical reaction of the membrane electrode assembly of the polymer electrolyte fuel cell described above is shown in Scheme 1, and the electrochemical reaction of the membrane electrode assembly of the direct methanol fuel cell is shown in Scheme 1.

The ^{_{anode: H 2 → 2H + + 2e}} -

^{_{Cathode: 1 / 2O 2 + 2H +}} + 2e - → H 2 O

_{Anode: CH 3 OH + H 2 O} → CO 2 + 6H + + 6e -

^{_{Cathode: 3 / 2O 2 + 6H +}} + 6e - → 3H 2 O

The membrane electrode assembly may be implemented as a single cell battery, stacked in series to form a stacked battery, or stacked in parallel to form a flat battery. In either case, in the mass production process of the product, prior to mounting the manufactured membrane electrode assembly to the fuel cell system, the membrane electrode assembly is tested for its desired performance, and / or the membrane is activated. The preliminary pretreatment should be performed on the electrode assembly.

However, carrying out the above test and / or preliminary treatment for the membrane electrode assembly one for each membrane electrode assembly is a waste of time and money. Accordingly, it has been desirable to develop a device that supports multiple MEAs for devices that can conveniently and accurately perform the above test and / or pretreatment of multiple membrane electrode assemblies at once.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a multi-cell support apparatus for constructing a test / preliminary processing apparatus that can conveniently and accurately perform a test and / or preliminary processing on a plurality of membrane electrode assemblies. Its purpose is to.

MEA support apparatus of the present invention for achieving the above object, the first multi-cell binding plate having a fuel supply structure; A second multi cell binding plate having an air supply structure; And a fluid pressure compressing the first multi-cell plate and the second multi-cell plate so that a uniform compressive force is applied to each MEA while a plurality of MEAs are supported between the first multi-cell plate and the second multi-cell plate. It characterized in that it comprises a press.

The expression support device used in the definition of the present invention does not mean a device for assembling a membrane electrode assembly, but for testing or pretreatment of each membrane electrode assembly, the membrane electrode during the test or pretreatment time is performed. Means a device for fixing the assembly. That is, the MEA support device of the present invention is intended to be used as a component of a test device or a pretreatment device of the MEA.

Figure 2 shows the overall structure of a multi-cell support device according to an embodiment of the present invention.

The illustrated multi-cell support device includes: a first multi-cell binding plate 20 for placing the membrane electrode assemblies for test / activation with the anode side in contact; A second multi-cell binding plate 30 which is bound in contact with the cathode sides of the membrane electrode assemblies; And fluid pressure presses 40 and 50 for binding the first and second multi-cell binding plates 20 and 30 to a uniform pressure with the membrane electrode assemblies therebetween.

That is, the multi-cell support device of the present embodiment includes first and second multi-cell binding plates 20 and 30 disposed on both upper and lower sides with a plurality of MEAs to be bound therebetween. The second multi-cell binding plate 30 has a means for supplying an oxidant (eg, air) to the cathode electrode, and the first multi-cell binding plate 30 has an inlet and an outlet for supplying fuel to the anode electrode. It can be provided.

The hydraulic presses 40 and 50 may include a first multi-cell binding plate 20 and a second multi-cell binding plate in a state in which a plurality of MEAs are placed between the first and second multi-cell binding plates 20 and 30. A plurality of MEAs are compressed by applying a force in a direction facing 30 to the first multi-cell binding plate 20 and the plurality of MEAs and the second multi-cell binding plate 30 in close contact with each other. The fluid pressure presses 40 and 50 can apply a constant pressure to a plurality of MEAs almost uniformly, thereby reducing the possibility of test errors and activation failures caused by different engagements in only one MEA.

Even when the hydraulic press is applied, as shown in FIG. 2, the first and second multi-cell binding plates 20 and 30 are both movably embodied by the hydraulic press, or among the first and second multi-cell binding plates. One can be fixed and only the other can be implemented to be movable by a hydraulic press. In the former case, the fluid pressure press is a second press contacting the first multi-cell binding plate 30 and applying a pressure to the first press 40 and the second multi-cell binding plate 30 to apply an arbitrary pressure. And 50.

The first multi-cell binding plate 20 includes a plate frame 24 which provides mechanical strength and transmits the fluid pressure by the first press 40 of the fluid press to the MEA to be bound, which plate frame ( 24, the first frame 23 is joined to the fluid pressure press 40; And a second frame 24 in which a fuel supply structure such as a fuel supply channel 26 to the anode of the MEA, an internal flow path between the inlet port and the fuel supply channel, and an internal flow path between the outlet port and the fuel supply channel is formed. . It is preferable that the first frame 23 and the second frame 24 have a structure that can be detached from each other, since the second frame 24 can be exchanged according to the type of MEA to be tested or activated.

In addition, the second frame 24 of the illustrated first multi-cell binding plate 20 is provided with a step on its upper surface and a surface in contact with the anode of the MEA, and the MEA is attached to the first multi-cell binding plate 20. The mounting groove A can be formed which makes it easy to arrange on.

Among the multi-cell binding plates 20, the first frame 23 is made of a material having excellent strength, durability, and low cost, such as stainless steel, and the second frame is made of non-conductive durable material such as graphite. Can be.

3A to 3C are top plan views illustrating one embodiment of an anode side first multi-cell binding plate that may be applied to the MEA support device of FIG. 2. In the drawings, the structure of the first frame and the second frame and the structure of the mounting groove (A of FIG. 2), which are difficult to be shown in a plan view and are sufficiently represented in FIG.

The anode-side first multi-cell binding plate 20 of FIG. 3A includes a frame for imparting mechanical strength of the plate; A fuel supply channel 26 formed at a position where each MEA is raised, for supplying fuel to each MEA; An inlet port 27a for introducing fuel into the fuel supply channel 26; An outlet port 27b for discharging fuel from the fuel supply channel 26; And a sensing strip 29 for sensing electrical characteristics around the fuel supply channel 26.

As shown in FIG. 2, the frame may include a first frame contacting the fluid press and a second frame 24 in which the fuel supply channel 26 is formed. The first frame and the second frame can be detachably implemented with each other, which can be applied to change the second frame according to the size or type of the MEA to the first frame fixed to the hydraulic press, equipment use It has the advantage of giving flexibility.

The inlet port 27a is connected to the fuel supply channel 26 through an inlet pipe formed inside the frame, and the outlet port 27b is connected to the fuel supply channel 26 through an outlet pipe formed inside the frame. do.

Depending on the implementation, it is possible to form recessed mounting grooves for placing the MEA in the area around the fuel supply channel 26 of the frame. In the case of forming the mounting groove, convenience is given to the operation of positioning the MEA in the MEA supporting apparatus of the present embodiment, but the shape and size of the applicable MEA are limited.

The sensing strip 29 is for measuring electrical measurements (voltage, current) of the MEA anode to measure the electrical characteristics of the MEA, and the fuel supply channel is in contact with the anode electrode of the MEA fastened to the MEA support device. Implement near the outskirts. When the multi-cell support device of the present embodiment performs only activation without performing a test for the MEA, the sensing strip may be omitted.

The anode-side first multi-cell binding plate shown in FIG. 3B differs from FIG. 3A in that the fuel supply channel 26 'has a zigzag flow path, and the other components are almost the same as in FIG. 3A. Do. In general, the flow path of the bipolar plate constituting the fuel cell stack together with the MEA has a zigzag flow path. The anode-side multi-cell binding plate of FIG. 3B has a shape similar to the flow path of the bipolar plate assembled into the stack together with the MEA. It has a fuel supply channel. Thus, the anode-side multi-cell binding plate of FIG. 3B has the advantage that the testing or activation of the MEA is performed in an environment similar to that of the stack where the MEA will later be located.

 In the anode-side first multi-cell binding plate shown in FIG. 3C, the fuel supply channel forms three subchannels 26-1, 26-2, and 26-3 for each MEA, and each sub-channel of the fuel supply channel is shown. Three inlets 27a-1, 27a-2, 27a-3 and three outlets 27b-1, 27b-2, for entering and exiting fuel at 26-1, 26-2, 26-3, 27b-3) differs from FIG. 3a. In the figure, three subchannels are implemented, but two or more subchannels may be implemented.

The anode side multi-cell binding plate of FIG. 3C has the advantage of enabling testing and / or activation for different sized MEAs. That is, when the width of the MEA is small, only one inlet 27a-1 and one outlet 27b-1 are used to supply fuel to only one sub-channel 26-1, and the width of the MEA is the largest. Supplies fuel to all three sub-channels 26-1, 26-2 and 26-3.

In the drawing, each sub-channel 26-1, 26-2, 26-3 is manufactured in a C-shaped loop shape to secure a space for installing the sensing strip 29 ", but the connection line to the sensing strip is located inside the frame. In the case of an implementation only for the purpose of activation or activation, it may be manufactured in an O-shaped ring shape.

4 illustrates one embodiment of a cathode-side second multi-cell binding plate that may be applied to the MEA support device of FIG. 2.

Similarly to the second multi-cell binding plate on the cathode side as shown in FIG. 3A, an active implementation of forming an air supply channel and blowing air into the air supply channel by a separate blowing means is also possible. Manual implementations like this are advantageous in terms of manufacturing and maintenance costs. This is not an environment in which sufficient air is supplied due to the density of the stack even in the case of a fuel cell stack that actually blows air actively, and thus, in the case of the cathode-side second multi-cell binding plate that manually supplies air as shown in FIG. This is because there is no difference in terms of air supply efficiency.

The illustrated cathode-side second multi-cell binding plate is composed of a plate frame 32 having a vent hole 34 and a sensing strip 39 formed in a region where the cathode of the MEA is in contact. When the multi-cell support device of the present embodiment performs only activation without performing a test for the MEA, the sensing strip may be omitted. As shown in FIG. 2, the engagement portion between the plate frame 32 and the fluid pressure press 50 having the vent hole 34 formed therein does not include the vent hole 34 of the frame so that the vent hole 34 is not blocked. A part formed in the plate frame 32 may be implemented to be joined to the fluid pressure press 50 only in a part, and an air hole (not shown) connected to the air hole of the frame may be formed in the coupling part B. Means should be ensured to ensure the aeration of the pores 34.

5 is a schematic diagram of a multi-MEA test station to which a multi-cell support apparatus according to an exemplary embodiment of the present invention is applied. The MEA test station is not a category of the present invention, but will be described to show an example in which the MEA support device according to the present invention is used.

Referring to FIG. 5, the multi-MEA test station of the present invention is a chamber 110, auto pressing means 120, reactants for testing and activating multiple MEAs with a single device. A supply means 130, a multi-loader 140, and purging means 150.

The chamber 110 has an interior space for accommodating a plurality of MEAs. For example, the chamber 110 is sized to arrange the five layers of MEA in five layers. As the chamber 110, a constant temperature and / or humidity chamber may be used to provide a correct evaluation environment of the MEA. In addition, the chamber 110 preferably includes a temperature sensor 112 installed at a position capable of detecting the temperature of the MEA most accurately when the plurality of MEAs are operated. The position at which the temperature of the MEA can be detected most accurately includes a position in direct contact with the MEA or a position in contact with the automatic pressing unit 120 surrounding the MEA.

The auto-pressure unit 120 supplies fuel and oxidant to the anode and cathode electrodes of each MEA, and arranges a plurality of MEAs on a body provided with a plurality of bipolar plates for accumulating electrical energy generated by each MEA. The pressure is to form the same conditions as when the stack is pressed. In the present embodiment, the automatic pressing unit 120 is composed of five automatic pressing units, each automatic pressing unit 120 is installed to independently test and activate the five MEA.

The reactant supply means 130 includes a device for supplying fuel and oxidant for operating a fuel cell to a plurality of MEAs pressurized by the automatic pressurizing unit 120. The reactant supply unit 130 distributes and supplies the fuel supplied from the fuel storage container 132 storing fuel, the fuel pump P1 134a for supplying fuel, and the fuel supplied from the fuel pump 134a to a plurality of MEAs. The first mass flow controller (MFC 1) (136a), and the fuel from the first flow flow controller 136a to guide the automatic pressure unit 120 and the automatic pressure unit 120 And a first pipe 138a for guiding the fluid from the first flow controller 136a. In addition, the reactant supply means 130 is a second flow rate control device for supplying air supplied from the air pump (P2) (134b) for supplying air as an oxidant, the air pump 134b to a plurality of MEA (the second mass flow controller: MFC 2) (136b), and guides the air from the second flow control device (136b) to the automatic pressure unit 120 and the second flow flow control of the fluid from the automatic pressure unit 120 A second pipe 138b is guided to the device 136b.

The first flow rate control device 136a described above is connected to at least one fuel pump 134a, and the second flow rate control device 136b is connected to at least one air pump 134b. In addition, the first and second flow control devices (136a, 136b) supply fuel and air simultaneously or sequentially to the five floors in which the MEAs are arranged, or supply the fuel and air simultaneously or sequentially to the five MEAs in each floor. Is implemented.

The multi loader 140 controls the test and activation environment for the plurality of MEAs stored in the chamber 110 and performs the test and activation for the plurality of MEAs. The multi-loader 140 is coupled to the chamber 110 and controls the temperature and humidity of the chamber 110, and desired characteristic parameters such as voltage, current, impedance, phase angle, power failure for each MEA housed in the chamber 110. At least one of the doses is measured and the performance of each MEA is evaluated based on the measured characteristic parameters of the MEA.

The multi-loader 140 is a power supply unit 142 for supplying internal power or applying a direct current signal or an alternating current signal to the MEA housed in the chamber 110, and voltage, current, impedance, and the like from the MEA housed in the chamber 110. A sensing unit 144 for sensing any one of phase angle, capacitance, and a combination thereof, a plurality of MEA test and activation environments such as temperature and humidity of chamber 110, supply of reactant supply 130 and / or Or it is implemented to include a control unit 146 to control the feed rate and the like to perform a test and activation process of a plurality of MEA.

The controller 146 stores the characteristic parameters detected from the plurality of MEAs, and based on the detected characteristic parameters, voltage-current characteristics, catalyst utilization rates, crossover characteristics, temperature dependent characteristics, fuel concentration dependent characteristics, and the like of each MEA, It can be implemented to evaluate the performance of the electrolyte membrane thickness dependent properties, durability and the like.

Purifier 150 purges a plurality of MEAs that have been tested and activated in chamber 110 to prepare the MEAs in a state suitable for stack fabrication and / or for transport and storage. As the purifier 150, a nitrogen purge apparatus may be used. When purifying the MEA using the nitrogen purging device as the purifying device 150, the nitrogen purging device is coupled to the air pump 134b by an operation such as a valve operated by the control of the control unit 146 and the first fluid flow. The regulator 136a and / or the second fluid flow regulator 136b may be implemented to purify the cathode side first channel and / or the anode side second channel of the plurality of MEAs.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

As described above, when the multi-cell support device according to the present invention is applied to a MEA test device or a processing (activation) device, the process for testing and activating a plurality of MEAs can be simplified and the processing time can be shortened. .

Accordingly, unnecessary cost incurred due to stack dismantling due to stack failure can be reduced and contribute to process automation for test and activation.

Claims (8)

A first multi-cell binding plate having a fuel supply structure; A second multi cell binding plate having an air supply structure; And A fluid pressure press for compressing the first multi-cell plate and the second multi-cell plate so that a uniform compressive force is applied to each MEA while a plurality of MEAs are supported between the first multi-cell plate and the second multi-cell plate. Multi-cell support device comprising a. The method of claim 1, wherein the first multi-cell binding plate, Plate frame; A fuel supply channel for supplying fuel to the MEA fastened and formed on the plate frame surface; An inlet through which fuel enters the fuel supply channel from the outside; And Outlet port through which the fuel used in the fuel supply channel flows out Multi-cell support device comprising a. 3. The fuel supply system of claim 2, wherein the fuel supply channel; A multi-cell support device comprising a zigzag flow path. The method of claim 2, The fuel supply channel includes a plurality of sub-channels that are used depending on the size of the MEA to be fastened, The inlet and outlet are multi-cell support device characterized in that provided as the number of the sub-channel. The method of claim 2, wherein the plate frame, A first frame joined to the fluid pressure press; And And a second frame in which an internal flow path between the fuel supply channel, the inlet port and the fuel supply channel, and an internal flow path between the outlet port and the fuel supply channel are formed, The first frame and the second frame is a multi-cell support device, characterized in that the removable structure. The method of claim 1, And a concave shape mounting groove for positioning the MEA to be fastened to the frame region near the fuel supply channel. The method of claim 1, wherein the second multi-cell binding plate, Multi-cell support device characterized in that it comprises a plate frame formed with a plurality of vents. The method of claim 1, A first sensing strip in contact with the anode of the MEA to be fastened to measure its electrical characteristics; And And a second sensing strip in contact with the cathode of the MEA to be fastened to measure its electrical characteristics.

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