KR100551136B1 - The system for preparing the membrane electrode assembly for fuel cell - Google Patents

Abstract

The present invention relates to a system for manufacturing a MEA (Membrane electrode assembly), which is a component of the unit cell of a polymer electrolyte fuel cell (PEMFC) and a direct methanol fuel cell (DMFC). ,

A spray nozzle for spraying a catalyst solution; A supply vessel supplying the catalyst solution to the injection nozzle quantitatively according to a gas pressurized method; A pressurized spray apparatus comprising a transfer device for moving the head of the spray nozzle to a point on the polymer electrolyte membrane or diffusion layer for which the catalyst solution coating is desired; And it provides a system for producing an electrode membrane assembly for an automated fuel cell comprising a warm air drying device.

The present invention provides a method for mass production of MEA with uniform performance.

Fuel cell, electrode membrane assembly

Description

Manufacturing system of electrode membrane assembly for fuel cell {THE SYSTEM FOR PREPARING THE MEMBRANE ELECTRODE ASSEMBLY FOR FUEL CELL}

1 is a schematic diagram of an automation system for manufacturing MEA according to the present invention.

1: solution supply container 2: frame

3: automatic feeder 4: spray nozzle

5: pattern frame 6: polymer electrolyte membrane or diffusion layer

7: Rotary actuator

8: Hot air blower (Gas blower)

2 is a detail view of the solution storage container.

9: solution outlet 10: carrier gas inlet

11: outlet tube 12: stirrer

3 is a detailed view of the membrane frame.

The present invention relates to a system for producing an electrode membrane assembly for a fuel cell.

Fuel cells are a new way of generating electricity by using electrons generated during the redox reaction of hydrogen and oxygen. The unit cell structure of a fuel cell has a structure in which a cathode and an anode are coated on both sides of an electrolyte membrane made of a polymer material, which is called a MEA (Membrane Electrode Assembly). In the anode, hydrogen or methanol, which is a fuel, is supplied and reacts on the electrode catalyst to generate hydrogen ions (H +). In the cathode, hydrogen ions and oxygen that pass through the polymer electrolyte membrane are combined to generate pure water. This series of reactions then takes place in the MEA, which is made by thin-coating a cathode catalyst material (primarily Pt or Pt / Ru) and an anode catalyst material (primarily Pt) on both sides of the solid polymer membrane.

Conventional methods for manufacturing MEAs are prepared by mixing a catalyst material, a proton conductive binder material, and a solvent of water or an alcohol-based solvent to prepare a paste, which is prepared using carbon cloth or carbon paper ( carbon paper) and then thermally fused to the proton conductive electrolyte membrane to transfer. This method is a kind of indirect coating method. When catalyst material is coated on porous carbon cloth or carbon paper, it does not distribute evenly on the surface and penetrates into the pores, which actually reduces the utilization of catalyst during MEA operation. The main disadvantage is that the performance is reduced. In addition, the process may be complicated because the electrode layer already formed needs to be secondary heat-sealed again to the proton conductive film, and the interface formation between the electrolyte material and the catalyst layer may be discontinuously formed.

In addition to the above manufacturing method, conventionally performed methods include mixing the catalyst material, the proton conductive binder material, and the water or alcohol solvent to make an electrode paste, and using the screen printing method on the surface of the proton conductive electrolyte membrane. There is a direct transfer coating method. This method mimics the general print production process. Patterning is advantageous and suitable for mass production. Swelling in which the volume expands in all directions when water or alcohol solvents come into contact with the polymer electrolyte membrane during the process. (swelling) is a disadvantage that it is difficult to obtain a uniform surface coating layer, as well as a loss of the catalyst material and difficult to control the viscosity of the solution.

In addition, a method of forming an electrode paste by mixing a catalyst material, a proton conductive binder material, and water or an alcohol solvent and spraying the polymer electrolyte membrane using an air spray to form a catalyst layer have. This method has the advantage of ensuring the continuity of the interface and improving the utilization rate of the catalyst by forming a thin film catalyst layer on the surface of the polymer electrolyte membrane in a direct manner. However, there is a problem in that the nozzle is easily clogged as the solvent evaporates during the spraying. Therefore, in order to supplement these problems and to improve the uniformity of the catalyst layer thickness and catalyst loading amount, automation of the catalyst solution supply method and the coating process is essential.

The present invention overcomes the problems raised in the coating method using the injection nozzle in the MEA manufacturing, improve the uniformity of the electrode catalyst layer when manufacturing the MEA and at the same time facilitate the control and patterning of the precise coating amount and the polymer An object of the present invention is to manufacture a high quality MEA with a minimum swelling phenomenon of the electrolyte membrane.

In order to achieve the above object, the present invention configures a new coating system employing a pressurized spray nozzle and a warm air drying method and has automated it.

The present invention is a spray nozzle for spraying a catalyst solution; A supply vessel supplying the catalyst solution to the injection nozzle quantitatively according to a gas pressurized method; A pressurized spray apparatus comprising a conveying portion for moving the head of the spray nozzle to a point on the desired polymer electrolyte membrane or diffusion layer for coating the catalyst solution; And

Hot Air Drying Unit

It provides a manufacturing system of an electrode membrane assembly for a fuel cell comprising a.

An overall schematic and detailed illustration of one embodiment of a system for manufacturing an electrode membrane assembly for a fuel cell employing an automated pressurized injection nozzle and a warm air drying method according to the present invention is shown in FIGS. 1, 2, and 3. Is shown. Hereinafter, the present invention will be described with reference to the drawings.

In FIG. 1, the automatic transfer unit 3 performs coating at a desired point through the head of the injection nozzle 4 while moving according to the coordinates in the x, y, z axis directions according to the input program. At this time, the catalyst solution is quantitatively supplied to the injection nozzle 4 through the supply vessel 1 according to the gas pressurization method, and a detailed picture of the supply vessel 1 is shown in FIG. 2.

As shown in FIG. 2, the supply vessel is hermetically sealed from the outside and has a solution outlet 9, a carrier gas inlet 10, a tube 11, and an agitator 12. Stirrer 12 prevents entanglement of the catalyst solution. Thus, as the carrier gas enters, the well stirred catalyst solution passes through the tube 11 and is discharged by a predetermined amount through the solution outlet 9.

At this time, when the solution outlet 9 is installed on the upper surface instead of the lower portion, there is an advantage that only the well stirred catalyst solution is discharged. This is because the tube may be clogged during use when the agitated catalyst mass is left as it is. The solution outlet 9 can be connected to the spray nozzle 4 via a hose or the like.

As the carrier gas used, an inert gas such as argon (Ar), helium (He), nitrogen (N ₂ ), air, or the like may be used.

The amount of solution discharged is determined by the pressure of the carrier gas, with a preferred pressure range of 0.01 to 1 atmosphere (atm). If the pressure is too small, the discharge amount is too small to cause a long time to carry the desired amount, and if the pressure is too high, the film is swelled and a uniform coating is difficult.

The catalyst solution discharged through the spray nozzle 4 is coated on the polymer electrolyte membrane or the diffusion layer between the pattern frames 5. A detailed illustration of the pattern frame is shown in FIG. 3.

The left figure of FIG. 3 shows the patterned side of the pattern frame as seen from above. At this time, the shape and number of the pattern frame can be arbitrarily determined, preferably 2-6 square or rectangular. In addition, the pattern frame is slanted toward the surface to be coated, which allows the catalyst solution to be smoothly coated on the desired surface without being adhered to the wall during coating, and the preferred angle is 10-70 degrees. Various materials such as aluminum (Al), stainless steel, and copper (Cu) may be used as the material of the pattern frame, and a rotary actuator 7 capable of rotating 180 degrees when double-side coating is required is patterned. It can be installed on the side of the frame to increase convenience.

In this case, when using a polymer electrolyte membrane, pretreatment is performed before use to facilitate contact with the coating solution. It is used after soaking a predetermined time in water or an organic solvent such as isopropyl alcohol (IPA), methanol, ethanol, or a mixture thereof Preferably, it is used after soaking in water for about 1-60 minutes.

The present invention is equipped with a hot air dryer (8) to minimize the smooth drying of the coated base material and in particular the swelling of the polymer electrolyte membrane by the solvent in the sprayed catalyst solution. The heated air or inert gas is discharged through the hot air dryer to contact the base metal, and drying is performed. The discharge and temperature of the gas can be controlled by using a speed controller and a temperature controller of a rotary blade inside the dryer. At this time, a preferable temperature range of the exhaust gas is 20 to 90 ° C. Above 120 ° C., film degradation occurs.

As described above, the MEA manufacturing system of the present invention has been improved by introducing a new concept of parts that may be a problem in the general spray nozzle coating process, and the above-described series of processes are all controlled automatically by the control panel. This allows for easy and simple mass production of MEAs with uniform performance.

The present invention improves the conventional problem by introducing a new concept and automation equipment in the method that has been carried out manually and in small quantities, and by providing an automated coating equipment in the MEA manufacturing stage, by uniformly applying the catalyst material to the polymer membrane The catalyst layer can improve the reliability of battery performance and at the same time enable mass production of large area MEAs, which can greatly contribute to the commercialization of fuel cells.

Claims (9)

A spray nozzle for spraying a catalyst solution; A supply vessel supplying the catalyst solution to the injection nozzle quantitatively according to a gas pressurized method; A pressurized spray apparatus comprising a conveying portion for moving the head of the spray nozzle to a point on the desired polymer electrolyte membrane or diffusion layer for coating the catalyst solution; And a warm air drying device, For a fuel cell, the polymer electrolyte membrane or diffusion layer to be coated with the catalyst solution is placed between the pattern frames provided with the rotary actuator, thereby coating the polymer electrolyte membrane or the diffusion layer with the catalyst solution according to the pattern frame shape. Production system for electrode membrane assembly. The system of claim 1, wherein the supply vessel comprises a catalyst solution outlet, a carrier gas inlet, a tube, and an agitator, wherein the catalyst solution outlet is installed on top of the supply vessel. The production system of an electrode membrane assembly for a fuel cell according to claim 2, wherein the amount of the catalyst solution discharged from the supply vessel is determined according to the pressure of the carrier gas, and the carrier gas pressure ranges from 0.01 to 1 atmosphere. delete delete The hot air drying apparatus of claim 1, wherein the warm air drying apparatus is operated when the catalyst solution is sprayed onto the polymer electrolyte membrane or the diffusion layer through a spray nozzle, thereby swelling the polymer electrolyte membrane or the diffusion layer by the solvent in the catalyst solution. A manufacturing system of an electrode membrane assembly for a fuel cell, characterized by being suppressed. The hot air drying apparatus of claim 1, wherein the hot air drying apparatus discharges heated air or inert gas, and the discharge and temperature of the gas are controlled by using a speed controller and a temperature controller of a rotary vane inside the drying apparatus, and the temperature of the discharge gas is 20 A system for producing an electrode membrane assembly for a fuel cell, wherein the electrode membrane assembly is characterized by being from 90 ° C to 90 ° C. 8. The system according to any one of claims 1 to 3, 6 and 7, wherein the pressurized spray apparatus and the warm air drying apparatus are operated in an automated process. 10. The system of claim 8, wherein the automated process includes an automatic transfer head and a control panel.

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