KR101121367B1 - Apparatus and method for coating of platinum catalysts for fuel cell - Google Patents

Abstract

A platinum catalyst coating device and a coating method for a fuel cell. The method generates a platinum plasma, provides an electric field to the platinum plasma to accelerate the platinum ions to travel in a predetermined direction, and applies a magnetic field to the platinum ions traveling in the predetermined direction to control the trajectory of the platinum ions. And implanting platinum ions traveling along the trajectory at predetermined intervals on an ion exchange membrane or a gas diffusion layer of a fuel cell.

Description

Platinum catalyst coating device and coating method for fuel cell {Apparatus and method for coating of platinum catalysts for fuel cell}

The present invention relates to a platinum catalyst coating device and a coating method of a fuel cell, and more particularly, to an apparatus and method for applying a platinum catalyst of a fuel cell using a small amount of platinum.

With the recent surge in oil prices and environmental issues as social issues, interest in fuel cells as an alternative energy is on the rise. Therefore, the development of fuel cells is currently being actively conducted with the aim of securing efficiency, mass production, stability and appropriate cost. In particular, PEMFC (proton exchange membrane fuel cell) type fuel cell is being actively researched as a fuel cell of automobiles. In addition, there is an advantage of having a relatively low operating temperature compared to other types of fuel cells, for example, SOFC (solid oxide fuel cell) type, the research and development is also in progress for home use.

This type of fuel cell is composed of a plurality of unit cells 10 as shown in FIG. Each cell 10 inside the fuel cell 1 is electrically connected in series and mechanically stacked. The metal plate 20 at both ends serves to apply pressure so that the connection state of each of the inner components can be good, and serves to supply the total voltage and current of the battery generated from the inside to the outside.

As shown in FIG. 2, each of the cells 10 is continuously stacked inside the fuel cell. Each cell 10 produces a voltage of 0.6 to 1V. The cell 10 can generate electricity by receiving oxygen in the air and hydrogen as a fuel.

Specifically, a membrane electrode assemply (MEA) 11, a gas diffusion layer (GDL) 12, a separator 13, and a gasket 14 for maintaining airtightness are unit cells. It consists of. The electrode membrane may include an ion exchange membrane (or electrolyte membrane) capable of moving hydrogen cations, and a catalyst layer may be formed on both sides of the ion exchange membrane to allow hydrogen and oxygen to react. Here, the ion exchange membrane is preferably composed of a polymer material having an excellent ion conductivity of about 50 to 100 mS / cm.

In general, the electrode film has a thickness of 112 to 117 µm, and platinum is used as a catalyst. Platinum has excellent properties of absorbing hydrogen, nanoparticles (1-5 nm), and a very large specific surface area (250-300 m 2 / g). However, since the price is high, it accounts for a considerable portion of the cost of the fuel cell.

Therefore, research is being conducted to minimize the amount of platinum used in the platinum catalyst layer to minimize the production cost of the fuel cell. In this case, however, when a small amount of platinum is used, it is difficult to uniformly arrange platinum on the ion exchange membrane, thereby causing a problem of having different ion exchange characteristics depending on the position.

In the present invention, in order to solve the above problems, using a small amount of platinum as a material of the catalyst layer, to provide a platinum catalyst coating device of the fuel cell is uniformly arranged on the ion exchange membrane or gas diffusion layer and a method for applying the same. to be.

The object of the present invention is to generate a platinum plasma, provide an electric field to the platinum plasma to accelerate the platinum ions to travel in a predetermined direction, and apply a magnetic field to the platinum ions traveling in the predetermined direction to It can be achieved by a method of applying a platinum catalyst of a fuel cell comprising controlling the progress trajectory, and injecting each of the platinum ions traveling along the trajectory at a predetermined interval on the ion exchange membrane or the gas diffusion layer of the fuel cell. .

Here, the platinum ions are preferably separated from the platinum plasma by the electric force generated from the electric field, and accelerated to be injected into the ion exchange membrane or the surface of the gas diffusion layer when incident on the ion exchange membrane.

At this time, by controlling the intensity of the electric field, it is possible to be designed to control the progress rate of the platinum ions or the depth at which the platinum ions are injected into the ion exchange membrane or the surface of the gas diffusion layer.

In addition, the strength of the magnetic field may be controlled to control the position at which the platinum ions are injected into the ion exchange membrane or the gas diffusion layer.

Furthermore, the filter is installed on a path through which the platinum ions travel, and may be designed to control the amount of the platinum ions injected into the ion exchange membrane.

In this case, the platinum ions are preferably arranged to form a 0.1 ~ 1nm spacing with adjacent platinum ions on the ion exchange membrane.

Here, the respective platinum ions are implanted to be spaced apart at predetermined intervals on the surface of the ion exchange membrane or the gas diffusion layer.

In this case, the accelerator may be configured to control the intensity of the electric field so as to control the depth of the platinum ions injected into the ion exchange membrane or the surface of the gas diffusion layer.

Alternatively, the track controller may be configured to control the direction or intensity of the magnetic field so as to adjust the position at which the platinum ions are injected onto the surface of the ion exchange membrane or the gas diffusion layer.

On the other hand, the inside of the vacuum chamber is preferably configured to further include a filter for controlling the amount of the platinum ions injected into the surface of the ion exchange membrane or the gas diffusion layer on the path of the platinum ions.

The plasma generator may include a stage on which platinum is seated and a light source generating the platinum plasma by irradiating light onto platinum seated on the stage.

According to the present invention, the platinum catalyst of the fuel cell is uniformly disposed at predetermined intervals on the surface of the ion exchange membrane or the gas diffusion layer by individually controlling the positions of the platinum ions, thereby reducing the manufacturing cost of the fuel cell. It has an effect and can show improved battery efficiency when using the same amount of platinum.

Hereinafter, a platinum catalyst coating apparatus and a platinum catalyst coating method of a fuel cell according to a preferred embodiment of the present invention will be described with reference to the drawings. However, in the present invention, platinum is used as a material of the catalyst layer, but it should be noted that the present invention may be configured using other materials other than platinum.

3 is a cross-sectional view schematically showing an internal configuration of a platinum catalyst applying apparatus of a fuel cell according to a preferred embodiment of the present invention.

As shown in FIG. 3, the platinum catalyst coating apparatus of the fuel cell according to the present invention includes a vacuum chamber 110 forming a space in which a process is performed, and various components are installed inside the vacuum chamber 110. do.

The platinum catalyst applying apparatus according to the present embodiment may be configured to transfer platinum to a plasma form and then inject platinum ions generated at this time into an ion exchange membrane or a gas diffusion layer surface S of the fuel cell. Therefore, a plasma generator 120 capable of generating platinum plasma and a target portion 150 on which the ion exchange membrane S of the fuel cell is mounted may be formed inside the vacuum chamber 110. In addition, an accelerator 130 and a track controller 140 may be provided between the plasma generator 120 and the target unit 150.

The plasma generator 120 includes a stage 121 for seating a substance for generating plasma, and a light source 122 for irradiating light such as a laser onto the stage 121. Therefore, when platinum is used as the catalyst material as in the present embodiment, after the platinum foil F is seated on the stage 121, it is possible to generate platinum plasma by irradiating a laser using the light source 122. At this time, the lower side of the stage 121 is provided with a separate heater 123 that can supply heat energy to the stage 121, it is possible to improve the generation efficiency of the plasma.

Meanwhile, an accelerator 130 capable of accelerating ions generated by the plasma generator may be installed at a position adjacent to the plasma generator 120. The accelerator 130 may be configured to form an electric field E in a predetermined section, including a region where the plasma is formed by the plasma generator 120. Here, the platinum plasma is composed of platinum ions and electrons, when the electric field (E) is formed by the accelerator 130, the platinum ions and electrons are applied to the electric force in different directions by the electric field (E).

At this time, the electric force acts on the platinum ions having the (+) property in the (-) direction of the electric field. The platinum ions move in a predetermined direction by the electric force. In this case, electrical energy provided to the platinum ions by the accelerator 130 is converted into kinetic energy of the platinum ions.

Specifically, platinum ions are separated from the platinum plasma while traveling in the negative direction of the electric field by the electric force. In addition, the accelerator 130 forms the electric field E along a predetermined section, and the platinum ions are accelerated by the electric force continuously applied while the electric field E is formed.

In this case, the accelerator may be configured using an electrode plate 131 installed inside the vacuum chamber 110. However, the present invention is not limited thereto, and as an example, the electric field may be provided in a predetermined section using various configurations.

On the other hand, the trajectory controller 140 is provided between the accelerator 130 and the target unit 150, and serves to control the progress trajectory of the platinum ions proceeding in an accelerated state by the accelerator 130. Therefore, the platinum ions accelerated by the electric field of the accelerator are controlled by the trajectory controller 140 to be incident on a predetermined position of the ion exchange membrane or the gas diffusion layer S mounted on the target unit 150. It is possible.

In this case, the trajectory controller 140 may provide a magnetic field on the path through which the platinum ions travel, and control the progress trajectory of the platinum ions. When platinum ions pass through the magnetic field B provided by the orbital controller 140, the platinum ions are applied with different Lorentz forces depending on the direction and intensity of the magnetic field. Therefore, the trajectory controller 140 may control the trajectory of the platinum ions by adjusting the strength and direction of the magnetic field B.

In this embodiment, the accelerator 130 and the trajectory controller 140 are sequentially positioned on the path through which platinum ions progress, but the present invention is not limited thereto. In addition, the accelerator and the trajectory controller may be configured to provide the electric field and the magnetic field together in a predetermined section of the progression path of the platinum ions, so that the acceleration may be accelerated by the accelerator and the trajectory controller may control the progress trajectory.

Meanwhile, as shown in FIG. 3, the other side of the plasma generator 120 may include a target unit 150 serving as an end point of the platinum ion path. In addition, the target unit 150 may be mounted with the ion exchange membrane S of the fuel cell. Therefore, the platinum ions generated in the plasma generator 120 may pass through the accelerator 130 and the trajectory controller 140, and then be injected into the ion exchange membrane or the gas diffusion layer S mounted on the target unit 150. .

According to the present invention, the platinum ions are accelerated by the accelerator 130 to reach the ion exchange membrane or the gas diffusion layer (S). At this time, the platinum ions are preferably injected into the ion exchange membrane (S) to a predetermined depth so as to be firmly coupled to the ion exchange membrane or the gas diffusion layer (S). Therefore, it is preferable that the accelerator 130 accelerates to the extent that platinum ions collide with the ion exchange membrane and can be implanted to a predetermined depth.

In addition, according to the present invention, it is possible to control the position where the platinum ions are injected into the ion exchange membrane or the gas diffusion layer S by the orbital controller 140. That is, it is possible to arrange | position uniformly so that platinum ion may not be biased on an ion exchange membrane or the gas diffusion layer S. FIG. Therefore, it is possible to improve the catalyst function of platinum compared with the prior art, and further, by arranging platinum ions in a required position, the amount of platinum used can be reduced.

In the present embodiment, a filter may be further provided on the path of the platinum ions. Here, the filter may selectively transmit the platinum ions to control the amount of platinum ions injected into the ion exchange membrane. In this case, platinum ions that do not pass through the filter may be configured to be collected and used again.

In this embodiment, as shown in FIG. 3, the filter 160 is installed in a direction perpendicular to the traveling direction of the platinum ions on the section where the platinum ions are accelerated by the accelerator 130. However, the present invention is not limited to the installation position of the filter 160, and of course, it is possible to change the installation to another appropriate position.

Hereinafter, a method of applying the platinum catalyst using the above-described embodiment will be described in detail.

FIG. 4 is a flowchart illustrating a method of applying the platinum catalyst using FIG. 3, and FIG. 5 is a schematic diagram schematically showing each step of FIG. 4.

As described above, the platinum catalyst applied by the present invention is a form in which platinum ions are injected onto an ion exchange membrane or a gas diffusion layer (S). Therefore, as shown in FIG. 4, the step of generating the platinum plasma is preceded (S1).

First, the platinum foil F is seated on the stage 121 of the plasma generator 120. Then, the stage 121 is irradiated with light such as a laser using the light source 122. At this time, the heater 123 provided under the stage 121 may be heated at the same time. In this case, the platinum foil that existed in the solid state is separated into platinum ions and electrons while being transferred to the plasma state.

When the platinum plasma is generated by the plasma generator 120, the accelerator 130 may be used to provide an electric field E to the platinum plasma (S2). At this time, the electric field E is applied to the platinum ions and the electrons of the platinum plasma in different directions. Accordingly, in this step, as shown in FIG. 5, the platinum ions are separated from the platinum plasma while traveling in a predetermined direction by the electric force. In addition, since the electric force is continuously applied to the platinum ions inside the section in which the electric field acts, the platinum ions are accelerated in the direction in which the electric force is applied by the electric force.

For example, assume an electric field E having a potential difference of U at the interval distance d. Here, the magnitude F of the electric force applied to the platinum ions having the charge amount q and the energy given from the electric field while the platinum ions pass through the electric field are as follows.

At this time, the platinum ions are accelerated by the electric force applied to the platinum ions continuously along the section, and the energy applied by the electric field is converted into the kinetic energy of the platinum ions.

That is, the accelerator 130 provides energy for allowing the platinum ions to travel from the vacuum chamber 110 to the target unit 150 through an electric field. At this time, the rate at which the platinum ions accelerated through the electric field proceeds through the electric field as follows.

(여기서,

는 백금 이온의 질량을 의미함)

(here,

Is the mass of platinum ions)

The speed of the platinum ions passing through the electric field may depend on the potential difference U of the electric field through which the platinum ions pass. That is, if the electric field strength is controlled by adjusting the potential difference between both ends of the electric field provided by the accelerator 130, it is possible to control the speed at which platinum ions progress.

On the other hand, when the platinum ions are accelerated by the accelerator and proceeds in a predetermined direction, the step of controlling the progress trajectory of the platinum ions can be performed (S3). As described above, the trajectory controller 140 is configured to provide a magnetic field B on a path through which platinum ions travel, and further control the strength and direction of the magnetic field. In this case, while Lorentz's force is applied to the platinum ions passing through the magnetic field, the platinum ions proceed with different orbits according to the strength and direction of the magnetic field as shown in FIG. 5.

For example, as shown in FIG. 5, it is assumed that the magnetic field B acting perpendicularly to the traveling direction of platinum ions acts at a distance of l. In this case, platinum ions form a track biased upward by Lorentz's force in the upward direction. At this time, the magnitude of the deflection occurring at a position separated by the magnetic field may be modified as follows.

That is, by controlling the direction of the magnetic field provided by the track controller 140, it is possible to control the direction in which the platinum ions are biased as they progress. In addition, by adjusting the intensity (B) of the magnetic field provided from the track controller 140 and the length (l) of the period in which the magnetic field is formed, it is possible to control the amount of bias of the platinum ions as it proceeds. Therefore, by controlling the direction and intensity of the magnetic field of the trajectory controller 140, the trajectory to which the platinum ions enter the target unit 150 is adjusted.

When platinum ions are incident on the target unit 150 along the trajectory, the platinum ions are injected into the ion exchange membrane or the gas diffusion layer S mounted on the target unit 150 (S4). Here, as described above, by adjusting the trajectory of the trajectory controller 140, the position where the platinum ions are incident on the ion exchange membrane S may be adjusted.

As described above, the platinum ions collide with the outer surface of the ion exchange membrane or the gas diffusion layer S, and are preferably inserted into the ion exchange membrane S by a predetermined depth. In this case, the bonding state between the platinum ions and the ion exchange membrane S is improved. Here, the depth d into which the platinum ions are injected into the ion exchange membrane S may be determined by the energy of the platinum ions. Therefore, by controlling the intensity of the electric field of the accelerator 130, it is possible to control the depth in which the platinum ions are injected into the ion exchange membrane (S).

On the other hand, it is preferable to exclude a plurality of platinum ions implanted into the ion exchange membrane (S) at each predetermined interval. Here, the predetermined intervals are intervals in which each platinum ion corresponds to a range in which the platinum ions can smoothly function as a catalyst on the ion exchange membrane or the gas diffusion layer (S). It can be set differently according to each.

In this case, the respective platinum ions are uniformly disposed on the ion exchange membrane or the gas diffusion layer S at predetermined intervals, and thus may exhibit even catalytic performance in all portions of the ion exchange membrane or the gas diffusion layer S. FIG. In addition, since the platinum is not deposited on the ion exchange membrane or the gas diffusion layer S, but the respective platinum ions are implanted at the required positions, the catalyst can be configured using a significantly smaller amount of platinum.

The configuration in which the platinum ions are spaced apart at predetermined intervals in the ion exchange membrane S may be implemented in various ways. In particular, in the present embodiment, it is possible to adjust the interval of the platinum ions incident on the ion exchange membrane S by using the filter 160 described above.

FIG. 6 is a diagram illustrating a path in which platinum ions enter the target unit 150 through the filter 160 in FIG. 3. As described above, in the present embodiment, the filter 160 is provided on the path of the platinum ions so that the amount of platinum ions injected into the ion exchange membrane or the gas diffusion layer S can be adjusted. Herein, a plurality of through holes 160a through which respective platinum ions can pass are formed inside the filter 160, and the ion exchange membrane or the gas diffusion layer S may be formed according to the area occupied by the through holes 160a in the cross section of the filter 160. ), The amount of platinum ions can be controlled.

In this case, the through hole 160a provided in the filter 160 of the present embodiment may be formed in a lattice shape as shown in FIG. 6. In addition, only a part of the plurality of platinum ions separated from the platinum plasma selectively pass through the through hole 160a of the filter and proceed to the ion exchange membrane S. Therefore, since the platinum ions are injected into the ion exchange membrane S in a shape corresponding to the arrangement of the through holes, the type of filter 160 can be changed to control the arrangement of platinum ions injected onto the ion exchange membrane. .

On the other hand, it is also possible to adjust the arrangement interval of the platinum by changing the characteristics of the electric field provided by the accelerator 130. For example, in the case where the platinum ions progress in parallel with each other in the electric field (when the equipotential surfaces of the electric field are parallel to each other), an interval where each platinum ion is arranged on the ion exchange membrane or the gas diffusion layer S Are spaced apart from each other at intervals corresponding to the arrangement intervals of the through holes 160a. However, in the case where each platinum ion proceeds in the form of condensation or divergence in the electric field (when the equipotential surface of the electric field forms a concave or convex surface), each platinum ion is reduced or expanded in comparison with the spacing of the through holes. Furnace may be injected into the ion exchange membrane or the gas diffusion layer (S).

On the other hand, as shown in Figure 6, when the size of the ion exchange membrane or the gas diffusion layer (S) is relatively large, the above-described process may be repeated a plurality of times. That is, after platinum ions are implanted at a part of the ion exchange membrane or the gas diffusion layer S (region I in FIG. 6) through the above-described steps, platinum plasma is again generated from the platinum foil, thereby accelerating the accelerator 130 and the orbit. The controller 140 is controlled to inject platinum ions into another position of the ion exchange membrane or the gas diffusion layer S (region II in FIG. 6). As such, it is possible to complete this process a plurality of times depending on the size of the ion exchange membrane or the gas diffusion layer S to complete the platinum catalyst. In this case, the platinum ions are preferably irradiated at different positions of the ion exchange membrane or the gas diffusion layer, and the trajectory controller 140 may adjust the position where the platinum ions are incident by changing the direction of the magnetic field each time.

It is preferable to apply a platinum catalyst such that each platinum ion is disposed on the ion exchange membrane at an interval of 0.1 to 1 nm by using the platinum catalyst coating device of the fuel cell, and in this embodiment, the platinum ion is coated so as to be disposed at 0.1 nm intervals. It was. In this case, the mass of platinum used per unit area (cm 2) of the platinum catalyst is as follows.

This reduces the amount of platinum used by 1/30 compared to conventional catalysts using 0.1 mg / cm 2 to 4 mg / cm 2 platinum per unit area, and according to the present invention, a platinum catalyst is applied using a small amount of platinum. It is possible to do

1 is a perspective view showing a conventional fuel cell,

2 is a cross-sectional view showing a cross section of the cell of FIG. 1;

3 is a cross-sectional view schematically showing an internal configuration of a platinum catalyst applying device of a fuel cell according to a preferred embodiment of the present invention;

4 is a flow chart showing a procedure of a method of applying a platinum catalyst using FIG.

5 is a schematic diagram schematically illustrating each step of FIG. 4, and

FIG. 6 is a diagram illustrating a path in which platinum ions enter a target unit through a filter in FIG. 3.

Claims (12)

Generate a platinum plasma, Providing an electric field to the platinum plasma, accelerating platinum ions to proceed, A magnetic field is applied to the advancing platinum ions to control the trajectory of the platinum ions, And injecting each of the platinum ions traveling along the orbit into the ion exchange membrane or the gas diffusion layer of the fuel cell at predetermined intervals. The method of claim 1, The platinum ions are separated from the platinum plasma by an electric force generated from the electric field, and accelerated to be injected into the ion exchange membrane or the gas diffusion layer when incident on the ion exchange membrane. Way. 3. The method of claim 2, The method of applying a platinum catalyst of a fuel cell, by controlling the intensity of the electric field, the depth of the platinum ion is injected into the ion exchange membrane or the gas diffusion layer. The method of claim 1, The method of applying a platinum catalyst of a fuel cell, by controlling the strength of the magnetic field, to control the position where the platinum ions are injected into the ion exchange membrane or the gas diffusion layer. The method of claim 1, A method of applying a platinum catalyst to a fuel cell, wherein the amount of the platinum ions injected into the ion exchange membrane or the gas diffusion layer is controlled by a filter provided on a path through which the platinum ions travel. The method of claim 1, And said platinum ions are arranged to form 0.1-1 nm spacing with adjacent platinum ions on said ion exchange membrane or gas diffusion layer. A vacuum chamber; A plasma generator installed inside the vacuum chamber to generate platinum plasma; An accelerator providing an electric field to the platinum plasma generated by the plasma generator to separate and accelerate platinum ions; A trajectory controller configured to provide a magnetic field on the propagation path of the platinum ions to control the trajectory of the platinum ions; And, Apparatus for applying a platinum catalyst of a fuel cell comprising a target portion through which the ion exchange membrane or the gas diffusion layer of the fuel cell into which the platinum ions are injected. The method of claim 7, wherein Each platinum ion is injected onto the ion exchange membrane or the gas diffusion layer so as to be spaced apart at a predetermined interval, platinum catalyst coating device of a fuel cell. The method of claim 8, The accelerator can control the intensity of the electric field, it is possible to adjust the depth of the platinum ion is injected into the ion exchange membrane or the gas diffusion layer, characterized in that the platinum catalyst coating device of the fuel cell. The method of claim 8, And the track controller controls the direction or the intensity of the magnetic field to adjust the position at which the platinum ions are injected onto the ion exchange membrane or the gas diffusion layer. The method of claim 8, And a filter for controlling an amount of the platinum ions injected into the ion exchange membrane or the gas diffusion layer on a path through which the platinum ions travel, inside the vacuum chamber. The method of claim 7, wherein And the plasma generator comprises a stage on which platinum is seated and a light source irradiating light onto platinum seated on the stage to generate the platinum plasma.

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