JP6722770B2 - Composite material separation plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite material separating plate , and more particularly to a composite material separating plate that improves electrical conductivity both in the surface and in the thickness direction.

The separation plate, which is a constituent element of the fuel cell stack, has a function as a supply passage of reaction gas (hydrogen and oxygen) and a discharge passage of water, and electrically connects the inside of the fuel cell stack. Due to such a function, the separator is required to have excellent electrical conductivity, mechanical properties, corrosion resistance and low hydrogen permeability.

Among large-sized secondary batteries, hydrogen fuel cells, redox flow batteries, and the like, which have recently received a great deal of attention, also include a separation plate. As described above, hydrogen fuel cells and redox flow cells that are driven in an acidic atmosphere are required to have electrical conductivity and mechanical properties, corrosion resistance, chemical resistance, and electrolyte impermeability.

In order to satisfy this, conventionally, a composite material separating plate in which a carbon fiber woven fabric is impregnated with a thermosetting resin has been manufactured. In order to impart electrical conductivity to such a composite material separating plate, a large amount of conductive powder having high conductivity must be mixed inside the thermosetting resin.

However, when a large amount of conductive powder is mixed with a thermosetting resin, it is not possible to secure high strength and cutoff rate of the fuel substance, and it is difficult to secure electrical characteristics even if a large amount of conductive powder is added. ..

As a related prior document, there is Korean Published Patent Publication No. 10-2005-0120257 (published on December 22, 2005), which describes a separator of a carbon composite material for a fuel cell.

It is an object of the present invention to provide a composite separator which improves electrical conductivity both in the surface and in the thickness direction.

Means to try to solve the problem

In order to achieve the above object, a composite separator according to an embodiment of the present invention includes a carbon fiber woven fabric; a conductive powder filled in the carbon fiber woven fabric; and an upper surface and a lower surface of the carbon fiber woven fabric, respectively. And an upper conductive coating layer and a lower conductive coating layer bonded to the carbon fiber woven fabric.

In order to achieve the above object, a method of manufacturing a composite material separating plate according to an embodiment of the present invention includes (a) a step of filling conductive powder inside a carbon fiber woven fabric; (b) carbon filled with the conductive powder. Forming upper and lower conductive coating layers on the upper and lower surfaces of the fiber woven fabric; and (c) pressing and curing the carbon fiber woven fabric and the upper and lower conductive coating layers by hot pressing to separate the composite material. Obtaining a plate;

The composite material separating plate and the method for manufacturing the same according to the present invention include firstly filling a conductive powder powder into the inside of a carbon fiber woven fabric, and then conducting the upper and lower conductive layers on both sides of the carbon fiber woven fabric filled with the conductive powder. By forming the functional coating layer, it is possible to improve the surface electrical conductivity in the x-axis direction and the y-axis direction as well as the vertical electrical conductivity in the z-axis direction.

Therefore, the composite separator according to the present invention can secure the surface electrical conductivity in the x-axis and the y-axis directions by the upper and lower conductive coating layers formed on both sides of the carbon fiber woven fabric, and at the same time, the carbon fiber woven fabric. Since the conductive powder filled inside has a structure that organically connects the carbon fiber fabrics, the vertical electrical characteristics in the z-axis direction are improved and the contact resistance is improved.

FIG. 3 is a cross-sectional view showing a composite material separating plate according to an embodiment of the present invention. The perspective view which showed the carbon fiber woven fabric of FIG. FIG. 6 is a process flow chart showing a method for manufacturing a composite material separating plate according to an embodiment of the present invention. 6A to 6C are process cross-sectional views showing a method for manufacturing a composite material separating plate according to an embodiment of the present invention. 6A to 6C are process cross-sectional views showing a method for manufacturing a composite material separating plate according to an embodiment of the present invention. 6A to 6C are process cross-sectional views showing a method for manufacturing a composite material separating plate according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become apparent with reference to the embodiments described in detail below in connection with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various different forms. However, the present invention is not limited to the embodiments disclosed in the present disclosure. The present invention is only defined by the scope of the claims, which is provided to inform those having ordinary skill in the art to the full scope of the invention. Like reference numerals in the entire specification refer to like elements.

Hereinafter, a composite material separating plate and a method of manufacturing the same according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a composite material separating plate according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the carbon fiber woven fabric of FIG.

Referring to FIGS. 1 and 2, a composite separator 100 according to an embodiment of the present invention includes a carbon fiber fabric 110, a conductive powder 120, and upper and lower conductive coating layers 130 and 140. At this time, the conductive powder 120 is filled in the carbon fiber woven fabric 110, and the carbon fiber woven fabric 110 filled with the conductive powder 120 is hot-pressed with the upper and lower conductive coating layers 130 and 140. It has a structure in which it is pressed and joined together by a press method.

The carbon fiber woven fabric 110 is used as a core substrate disposed in the middle of the composite material separating plate 100 and serves to improve the mechanical strength of the composite material separating plate 100. The carbon fiber woven fabric 110 preferably has a thickness of 200 to 400 μm. When the thickness of the carbon fiber woven fabric 110 is less than 200 μm, it is difficult to secure the mechanical strength because the thickness is thin. On the contrary, when the thickness of the carbon fiber woven fabric 110 exceeds 400 μm, there is no further effect increase and it acts on the factor that increases only the thickness and volume, which may result in a result contrary to weight reduction and thinning. , Not preferable.

At least one or more of the carbon fiber woven fabrics 110 may be vertically laminated. The carbon fiber woven fabric 110 may be manufactured by weaving a fiber bundle of 1,000 to 70,000 fibers as a weft yarn and a warp yarn, respectively. Accordingly, the carbon fiber woven fabric 110 may include the weft carbon fibers 112 arranged in the weft direction and the warp carbon fibers 114 arranged in the warp direction.

At this time, the fiber bundle of the carbon fiber woven fabric 110 has a circular or elliptical cross-sectional structure. The fiber bundle of the carbon fiber woven fabric 110 may have an average separation distance of 1.5 to 2.0 mm.

The conductive powder 120 is filled inside the carbon fiber woven fabric 110. The conductive powder 120 is filled in the carbon fiber woven fabric 110 by a coating method to improve the vertical electrical conductivity of the z-axis.

Therefore, the conductive powder 120 includes carbon nanotubes, graphite powder, chopped carbon fiber, carbon black, carbon powder, and graphite nanoplate. It may include one or more selected from graphite nanoplate and graphene.

At this time, the conductive powder 120 may be directly filled in the carbon fiber fabric 110 by a powder coating method. In addition, as the conductive powder 120, a dispersion liquid obtained by dispersing an organic solvent and an epoxy liquid resin having a viscosity of 100 cp or less is applied to both surfaces of the carbon fiber woven fabric 110 by an air injection method, and then dried to volatilize the organic solvent. The coating may be performed according to the method.

In this case, as the organic solvent, ethanol, butanol, ethyl acetate, octanol, ethoxyethanol pentanol, methoxyethanol, ethylene glycol, acetone, tetrahydrofuran, dimethylformamide, dimethylamine, dichloromethane and diethyl ether having excellent volatility are selected. One or more may be used.

The upper and lower conductive coating layers 130 and 140 are disposed on the upper surface and the lower surface of the carbon fiber fabric 110, respectively, and are bonded to the carbon fiber fabric 110.

The upper and lower conductive coating layers 130 and 140 are attached to the carbon fiber fabric 110 by a hot pressing process. At this time, the upper and lower conductive coating layers 130 and 140 have a structure in which the carbon fiber woven fabric 110 is partially impregnated into the carbon fiber woven fabric 110 by being bonded to the carbon fiber woven fabric 110 and is integrally connected to each other.

At this time, each of the upper and lower conductive coating layers 130 and 140 preferably has a thickness of 5 to 100 μm. If the thickness of each of the upper and lower conductive coating layers 130 and 140 is less than 5 μm, the handleability is poor and the surface electrical conductivity is reduced because the thickness is too thin. On the contrary, when the thickness of each of the upper and lower conductive coating layers 130 and 140 exceeds 100 μm, it is uneconomical because it does not further increase the effect and may act as a factor that increases only the manufacturing cost. ..

The upper and lower conductive coating layers 130 and 140 include a resin layer and a conductive filler impregnated in the resin layer, respectively.

The resin layer plays a role of improving mechanical strength. Such a resin layer is made of any material selected from thermosetting resins including phenol resin, epoxy resin, amino resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane resin and polyimide resin. To be done.

The conductive filler is added to and dispersed in the resin layer in order to improve the surface electrical conductivity of the x-axis and the y-axis. Therefore, the conductive filler may be a carbon nanotube, a graphite powder, a chopped carbon fiber, a carbon black, a carbon powder, or a graphite nanoplate. It may include one or more selected from nanoplate and graphene.

In this case, each upper and lower conductive coating layer 130 and 140, it is preferable that the conductive filler is added 15 to 25 wt% of the total weight as solid content basis. When the content of the conductive filler is less than 15% by weight , it may be difficult to secure the surface electric conductivity. On the contrary, when the content of the conductive filler exceeds 25% by weight , the nozzle may be clogged to cause defective coating.

If only the upper and lower conductive coating layers 130 and 140 are formed on both sides of the carbon fiber woven fabric 110 without filling the carbon fiber woven fabric 110 with the conductive powder 120, the core of the composite separating plate 110 may be formed. A large amount of conductive filler is concentrated only on the surface of the carbon fiber woven fabric 110 used as a material, and there is a problem that the vertical electrical conductivity in the z-axis direction is not good due to the problem that the conductive filler cannot penetrate into the inside of the carbon fiber woven fabric 110.

On the other hand, the composite material separating plate according to the embodiment of the present invention described above, after the powdery conductive powder is first filled into the inside of the carbon fiber woven fabric, the conductive powder-filled carbon fiber woven fabric is topped on both sides and The formation of the lower conductive coating layer can improve the vertical electrical conductivity in the z-axis direction as well as the surface electrical conductivity in the x-axis and y-axis directions.

Therefore, in the composite separator according to the embodiment of the present invention, the upper and lower conductive coating layers formed on both sides of the carbon fiber woven fabric can ensure surface electrical conductivity in the x-axis and y-axis directions, and Since the conductive powder filled in the carbon fiber fabric has a structure for organically connecting the carbon fiber fabrics, the vertical electrical characteristics in the z-axis direction are improved and the contact resistance is improved.

As a result, the composite material separator according to the embodiment of the present invention has a surface electric conductivity of 100 to 200 S/cm, a contact resistance of 10 mΩ /cm ² or less, and a bending strength of 80 MPa or less.

Hereinafter, a method for manufacturing a composite material separating plate according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a process flow chart showing a method of manufacturing a composite material separating plate according to an embodiment of the present invention, and FIGS. 4 to 6 are steps showing a method of manufacturing a composite material separating plate according to an embodiment of the present invention. FIG.

As shown in FIG. 3, a method of manufacturing a composite material separating plate according to an embodiment of the present invention includes a conductive powder filling step (S110), an upper and lower conductive coating layer forming step (S120), and a hot pressing step (S120). S130) is included.

Conductive Powder Filling As shown in FIGS. 3 and 4, in the conductive powder filling step (S110), conductive powder 120 is filled inside the carbon fiber woven fabric 110.

At least one carbon fiber fabric 110 may be vertically laminated. The carbon fiber woven fabric 110 may be manufactured by weaving a fiber bundle of 1,000 to 70,000 fibers as a weft yarn and a warp yarn, respectively. Accordingly, the carbon fiber woven fabric 110 may include the weft carbon fibers 112 arranged in the weft direction and the warp carbon fibers 114 arranged in the warp direction.

At this time, the fiber bundle of the carbon fiber woven fabric 110 has a circular or elliptical cross-sectional structure. Further, the fiber bundle of the carbon fiber woven fabric 110 may have an average separation distance of 1.5 to 2.0 mm.

The conductive powder 120 serves to improve the vertical electrical conductivity of the z-axis filled in the carbon fiber fabric 110 by a coating method.

In this step, it is preferable to vibrate the carbon fiber fabric 110 so that the conductive powder 120 can be easily inserted into the carbon fiber fabric 110.

Therefore, the conductive powder 120 includes carbon nanotubes, graphite powder, chopped carbon fiber, carbon black, carbon powder, and graphite nanoplate. It may include one or more selected from graphite nanoplate and graphene.

At this time, the conductive powder 120 may be directly filled in the carbon fiber fabric 110 by a powder coating method. In addition, as the conductive powder 120, a dispersion liquid obtained by dispersing an organic solvent and an epoxy liquid resin having a viscosity of 100 cp or less is applied to both surfaces of the carbon fiber woven fabric 110 by an air injection method, and then dried to volatilize the organic solvent. The coating may be performed according to the method.

In this case, as the organic solvent, ethanol, butanol, ethyl acetate, octanol, ethoxyethanol pentanol, methoxyethanol, ethylene glycol, acetone, tetrahydrofuran, dimethylformamide, dimethylamine, dichloromethane and diethyl ether having excellent volatility are selected. One or more may be used.

Forming Upper and Lower Conductive Coating Layers As shown in FIGS. 3 and 5, in the upper and lower conductive coating layer forming step (S120), the upper surface of the carbon fiber woven fabric 110 filled with the conductive powder 120 and Upper and lower conductive coating layers 130 and 140 are formed on the lower surface.

The upper and lower conductive coating layers 130 and 140 include a resin layer and a conductive filler impregnated in the resin layer, respectively.

The resin layer plays a role of improving mechanical strength. Such a resin layer is made of any material selected from thermosetting resins including phenol resin, epoxy resin, amino resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane resin and polyimide resin. To be done.

The conductive filler is added to and dispersed in the resin layer in order to improve the surface electrical conductivity of the x-axis and the y-axis. Therefore, the conductive filler may be a carbon nanotube, a graphite powder, a chopped carbon fiber, a carbon black, a carbon powder, or a graphite nanoplate. It may include one or more selected from nanoplate and graphene.

In this case, each upper and lower conductive coating layer 130 and 140, it is preferable that the conductive filler is added 15 to 25 wt% of the total weight as solid content basis. If the content of the conductive filler is less than 15% by weight , it may be difficult to secure the surface electric conductivity. On the contrary, when the content of the conductive filler exceeds 25% by weight , the nozzle may be clogged to cause defective coating.

In this step, the upper and lower conductive coating layers 130 and 140 may include at least one of knife coating, spray coating, dip coating, and bar coating methods. May be formed by. At this time, the thickness of the upper and lower conductive coating layers 130 and 140 can be adjusted by adjusting the spray time, the dip coating time, the height of the knife or the height of the bar.

Hot Pressing As shown in FIGS. 3 and 6, in the hot pressing step (S130), the carbon fiber woven fabric 110 and the upper and lower conductive coating layers 130 and 140 are pressed and cured by hot pressing to form a composite material separating plate. Get 100.

At this time, hot pressing is preferably performed at 130 to 200° C. under a pressure condition of 10 to 30 MPa for 10 to 60 minutes. If the hot pressing temperature is lower than 130° C. or the hot pressing time is shorter than 10 minutes, there is a high possibility that the curing will not be sufficiently performed. On the other hand, when the hot pressing temperature exceeds 200° C. or the hot pressing time exceeds 60 minutes, it is uneconomical because it does not further increase the effect and may act on the factor that increases only the manufacturing cost. ..

Further, when the hot pressing pressure is less than 10 MPa, the interfacial adhesion between the carbon fiber woven fabric 110 and the upper and lower conductive coating layers 130 and 140 is insufficient, and peeling may occur. On the contrary, if the hot pressing pressure exceeds 30 MPa, the carbon fiber woven fabric 110 and the upper and lower conductive coating layers 130 and 140 may be damaged by cracks due to excessive pressure.

During the hot pressing step (S130), the thickness of the carbon fiber fabric 110 and the thicknesses of the upper and lower conductive coating layers 130 and 140 are reduced due to the pressure bonding. After performing the hot pressing step (S130), the carbon fiber woven fabric 110 has a thickness of 200 to 400 μm, and the upper and lower conductive coating layers 130 and 140 have a thickness of 5 to 100 μm. May be.

The composite material separation plate manufactured by the above process (S110 to S130) is prepared by first filling the inside of the carbon fiber woven fabric with the conductive powder powder and then depositing the conductive powder on both sides of the carbon fiber woven fabric. And forming a lower conductive coating layer can improve vertical electrical conductivity in the z-axis direction as well as surface electrical conductivity in the x-axis and y-axis directions.

Accordingly, the composite separator manufactured by the method according to the embodiment of the present invention may have a surface electrical conductivity in the x-axis and y-axis directions by the upper and lower conductive coating layers formed on both sides of the carbon fiber fabric. In addition, the conductive powder filled inside the carbon fiber woven fabric has a structure to organically connect the carbon fiber woven fabrics to each other, thereby improving the vertical electrical characteristics in the z-axis direction and improving the contact. Resistance improves.

As a result, the composite material separator manufactured by the method according to the embodiment of the present invention has a surface electric conductivity of 100 to 200 S/cm, a contact resistance of 10 mΩ /cm ² or less, and a bending strength diagram of 80 MPa or less.

<Example>
Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to the preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention, and should not be construed as limiting the present invention in any way.

Since the contents not described here can be sufficiently inferred by a person skilled in the art, it will not be described.

1. Manufacture of composite material separating plate <Example 1>
A carbon fiber fabric having an average thickness of 250 μm was dispersed in acetone with 3 wt% of graphite nanoplates (GNP), and then dipped in a solution containing 10 wt% of an epoxy resin so as to bind GNP to the surface of the carbon fiber fabric. Ultrasonic (Sonication) vibration treatment was performed for 15 minutes, followed by drying at 60° C. for 1 hour to fill the inside of the carbon fiber woven fabric with graphite nanoplates (GNP).

Next, a dispersion prepared by adding 100 parts by weight of an epoxy resin and 15 parts by weight of carbon nanotubes (CNT) 5+graphite nanoplates (GNT) was coated on the upper and lower parts of the carbon fiber fabric to a thickness of 150 μm by a knife coating method. Then, the upper and lower conductive coating layers were formed.

Next, the carbon fiber woven fabric in which the graphite nanoplate (GNP) was inserted and the upper and lower conductive coating layers were pressed and cured by hot pressing for 30 minutes at a temperature of 150° C. and 20 MPa to form a composite having a thickness of 250 μm. A wood separating plate was manufactured.

<Example 2>
A composite material separating plate was manufactured in the same manner as in Example 1, except that the carbon fiber woven fabric was immersed in a solution in which 5 wt% of graphite nanoplate (GNP) and 10 wt% of epoxy resin were dispersed and mixed in acetone.

<Example 3>
A composite material separating plate was manufactured in the same manner as in Example 1, except that the carbon fiber woven fabric was immersed in a solution in which 3 wt% of graphite nanoplate (GNP) and 15 wt% of epoxy resin were mixed and mixed in acetone.
<Example 4>
Except that the carbon fiber woven fabric was immersed in a solution in which 3 wt% of graphite nanoplate (GNP) and 10 wt% of epoxy resin were mixed and mixed in acetone, subjected to ultrasonic vibration for 30 minutes (Sonication), and dried at 60°C for 1 hour Manufactured a composite material separating plate in the same manner as in Example 1.

<Example 5>
Except that the carbon fiber woven fabric was immersed in a solution in which 3 wt% of graphite nanoplate (GNP) and 10 wt% of epoxy resin were mixed and mixed in acetone, subjected to ultrasonic vibration for 15 minutes, and dried at 60° C. for 2 hours. Manufactured a composite material separating plate in the same manner as in Example 1.

<Comparative Example 1>
A dispersion of 100 parts by weight of epoxy resin and 15 parts by weight of carbon nanotubes (CNT) is coated on the upper and lower parts of the carbon fiber fabric to a thickness of 150 μm by the Knife coating method, and the upper and lower conductive coatings are formed. Layers were formed.

Next, the carbon fiber woven fabric and the upper and lower conductive coating layers were pressed and cured by hot pressing for 30 minutes under a pressure condition of 160° C. and 20 MPa to manufacture a composite material separation plate.

<Comparative example 2>
A composite material separating plate was manufactured in the same manner as in Example 1, except that the carbon fiber woven fabric was immersed in a solution in which 10 wt% graphite nanoplate (GNP) and 10 wt% epoxy resin were mixed and mixed in acetone.

<Comparative example 3>
A composite material separation plate was manufactured in the same manner as in Example 1, except that the carbon fiber woven fabric was immersed in a solution in which 3 wt% of graphite nanoplate (GNP) and 20 wt% of epoxy resin were mixed and mixed in acetone.

<Comparative example 4>
Except that the carbon fiber woven fabric was immersed in a solution in which 3 wt% of graphite nanoplate (GNP) and 10 wt% of epoxy resin were mixed and mixed in acetone, subjected to ultrasonic vibration for 5 minutes and dried at 60° C. for 1 hour. Manufactured a composite material separating plate in the same manner as in Example 1.

<Comparative Example 5>
Except that the carbon fiber woven fabric was immersed in a solution in which 3 wt% of graphite nanoplate (GNP) and 10 wt% of epoxy resin were mixed and mixed in acetone, and subjected to ultrasonic vibration for 15 minutes and then dried at 60° C. for 30 minutes. Manufactured a composite material separating plate in the same manner as in Example 1.

2. Evaluation of physical properties Table 1 shows the results of evaluation of physical properties of the composite material separation plates manufactured in Examples 1 to 5 and Comparative Examples 1 to 5.

1) Surface electric conductivity The surface electric conductivity was measured based on the 4-point probe method.

2) Contact resistance measurement method: After stacking copper electrode/GDL/separator/GDL/copper electrode in this order, the voltage drop generated between the copper electrodes was measured while applying a current of 5 A to both copper electrodes. .. The resistance was measured by dividing the current value applied to the voltage generated from this, and the resistance was multiplied by the area of the separation plate used for the measurement. At this time, the separation plate had a width of 5 cm and a length of 5 cm.

In order to draw the contact resistance between the copper electrode and the GDL, the resistance was measured after stacking copper electrode/GDL/copper electrode in this order, and the contact resistance of the separation plate was calculated by subtracting from the above value.

3) Flexural strength The flexural strength was measured based on ASTM D790-10. At this time, the size of the test piece used was 1.27 cm in width and 12.7 cm in length.

As shown in Table 1, in the case of the composite material separation plates manufactured according to Examples 1 to 5, the surface electric conductivity and the bending strength were not significantly different from those of Comparative Examples 1 to 5, but the contact resistances were compared. It can be seen that it has a significantly lower 6.9-7.5 mΩ /cm ² compared to Examples 1-5.

On the other hand, in the case of Comparative Example 1 in which the graphite nanoplate (GNP) was not filled, there was no big difference in the surface electric conductivity, but the contact resistance was measured to be considerably higher than that in Example 1, and the carbon content in the sample was The proportion was low and the flexural strength was measured a little higher.

In addition, in the case of Comparative Example 2 in which 10 wt% of graphite nanoplate (GNP) was added, the number of contact points between the carbon fiber and GNP was large, and the contact resistance was slightly reduced as compared with Example 1, indicating that Since the content is high, it can be confirmed that the bending strength is reduced.

In addition, in the case of Comparative Example 3 in which 20 wt% of the epoxy resin was added, an excessive amount of the epoxy resin covered the surface of the carbon fiber before the conductive coating layer was covered, so that it acted as an edge cutting layer, and compared with Example 1. Therefore, it can be confirmed that the contact resistance was measured to be considerably high.

In addition, in the case of Comparative Example 4 in which ultrasonic wave (Sonication) vibration treatment was performed for 5 minutes, the ultrasonic vibration treatment time was insufficient, and the graphite nanoplate (GNP) was not sufficiently filled into the inside of the carbon fiber, resulting in contact. It can be confirmed that the resistance was measured to be higher than that in Example 1.

Further, in the case of Comparative Example 5 in which the drying time was reduced to 30 minutes, since the drying time of acetone was insufficient, the conductive coating layer was applied while remaining in the sample and evaporated in the process of thermocompression bonding. It can be confirmed that pores are formed inside the test piece, the contact resistance is increased, and the flexural strength is decreased due to the pores.

Although the embodiments of the present invention have been mainly described above, various changes and modifications can be made at the level of an engineer having ordinary knowledge in the technical field to which the present invention belongs. It can be said that such changes and modifications belong to the present invention as long as they do not depart from the scope of the technical idea provided by the present invention. Therefore, the scope of rights of the present invention should be determined by the claims set forth below.

Claims (6)

Carbon fiber fabric having a thickness of 200-400 μm ;
Electrically conductive powder filled inside the carbon fiber fabric; and
Upper and lower electrically conductive coating layers which are respectively disposed on the upper surface and the lower surface of the carbon fiber woven fabric and which are bonded to the carbon fiber woven fabric;
Is a composite material separating plate containing
The upper and lower electrically conductive coating layers each include a resin layer and an electrically conductive filler impregnated in the resin layer,
The upper and lower electrically conductive coating layers each include the electrically conductive filler in an amount of 15 to 25 wt% in the electrically conductive coating layer,
The composite material separator has a surface electric conductivity of 100 to 200 S/cm, a contact resistance of 10 mΩ/cm or less, and a bending strength of 80 MPa or less.
Double if material separating plate. The carbon fiber fabric is
The composite material separating plate according to claim 1, wherein at least two or more are vertically stacked. The upper and lower electrically conductive coating layers are
The composite material separating plate according to claim 1, wherein a part of the carbon fiber woven fabric is impregnated into the carbon fiber woven fabric by being attached to the carbon fiber woven fabric, and the carbon fiber woven fabric and the carbon fiber woven fabric are integrally connected to each other. The upper and lower electrically conductive coating layers are
The composite separator according to claim 1, each having a thickness of 5 to 100 μm. The resin layer is
Phenol resins, epoxy resins, amino resins, urea resins, melamine resins, unsaturated polyester resins, which is formed by any material selected polyurethane resin and polyimide resins or al, composite separator plate of claim 1 .. The electrically conductive powder and the electrically conductive filler, respectively,
Carbon nanotube, graphite powder, chopped carbon fiber, carbon black, carbon powder, graphite nanophene and graphene phenoplate. The composite material separation plate according to claim 1 , comprising one or more selected from the above.

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