KR20210066650A - Separator plate for redox flow battery having current collector function and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a separator plate for a redox flow battery having a current collector function and a manufacturing method thereof, and more particularly, to a separator plate for a redox flow battery having a current collector function that can omit a current collector by adding the current collector function to a separator, and a manufacturing method thereof. A separator plate for a redox flow battery having a current collector function according to the present invention has a power withdrawal function by forming a connection part for connecting a cable for power extraction, can omit the current collector from the stack structure of the existing redox flow battery, and can improve the abrasion resistance and friction characteristics of the connection part by forming a DLC-coated protection layer on the surface of the connection part to which the cable is connected. The separator plate includes a main body and a protection layer.

Description

Separator plate for redox flow battery having current collector function and manufacturing method thereof

The present invention relates to a separator for a redox flow battery having a current collector function and a method for manufacturing the same, and more particularly, to a redox flow having a current collector function that can omit a current collector by adding a current collector function to the separator. It relates to a battery separator and a method for manufacturing the same.

Recently, renewable energy such as solar energy or wind energy has been in the spotlight as a method for suppressing greenhouse gas emission, which is a major cause of global warming, and many studies are being conducted to commercialize and disseminate them.

However, renewable energy is greatly influenced by the local environment or natural conditions. Moreover, renewable energy has a disadvantage in that it cannot continuously and evenly supply energy because the output fluctuates greatly.

Therefore, in order to use renewable energy for home or commercial use, a system capable of storing energy when the output is high and using the stored energy when the output is low is introduced and used.

A large-capacity secondary battery is used as such an energy storage system (ESS). For example, a large-capacity secondary battery storage system is being introduced to a large-scale solar power generation and wind power generation complex. The secondary battery for the large-capacity power storage includes a lead acid battery, a NaS battery, and a redox flow battery (RFB, redox flow battery).

Although the lead-acid battery is widely used commercially compared to other batteries, it has disadvantages such as low efficiency, maintenance cost due to periodic replacement, and treatment of industrial waste generated during battery replacement. In the case of a NaS battery, it has an advantage of high energy efficiency, but has a disadvantage of operating at a high temperature of 300°C or higher.

Redox flow batteries have a low maintenance cost, can be operated at room temperature, and have the characteristics of independently designing capacity and output, so a lot of research is being conducted as a high-capacity secondary battery.

A typical stack structure of a conventional redox flow battery includes an end plate, an insulating plate, a current collector, a separator, a gasket, a flow frame, an electrode, a gasket, a membrane, a gasket, an electrode, a flow frame, a gasket, a separator, a current collector, an insulating plate, and an end. It is composed of plates, and unit cells are formed from one plate to the next, and in general, one stack is constituted by stacking tens to hundreds of unit cells.

However, the conventional redox flow battery has a problem in that the thickness of the stack is increased by the current collector for current collection and the insulating plate and the end plate disposed outside the current collector.

Republic of Korea Patent Publication 10-2016-0035777 Republic of Korea Patent Publication 10-2016-0137861 Republic of Korea Patent Publication 10-2018-0105937

The present invention is to solve the conventional problem as described above, adding a power withdrawal function to the separator itself by forming a connection part capable of connecting a power line for power extraction to the separator, and stacking the existing redox flow battery An object of the present invention is to provide a separator for a redox flow battery having a current collector function that can omit a current collector and an insulating plate from the structure, and a method for manufacturing the same.

In addition, an object of the present invention is to provide a separator for a redox flow battery having a current collector function capable of improving abrasion resistance and friction characteristics of the separator, and a method for manufacturing the same.

A separator for a redox flow battery having a current collector function according to the present invention for achieving the above object includes a body formed including carbon felt and formed with a connection part extending to be exposed to the outside of the flow path frame on one side; and a protective layer formed to surround the surface of the connection part, wherein the protective layer is coated with diamond-like carbon.

The connection part and the protective layer of the separator for a redox flow battery having a current collector function according to the present invention have a fastening hole penetrating through the connection part and the protective layer in the thickness direction so that a cable for power extraction can be fastened. characterized.

The main body of the separator for a redox flow battery having a current collector function according to the present invention includes a main layer formed of the carbon felt, a first cover layer thermocompression-bonded to one surface of the main layer and formed of a conductive resin, and the main layer A second cover layer formed of a thermoplastic resin and thermocompression-bonded to the other surface of the second cover layer, and the first cover layer and the second cover layer are embedded in positions spaced apart from each other inside the main layer, and both sides of the main layer in the thickness direction Both ends facing toward the first cover layer and the second cover layer is characterized in that it is provided with a plurality of supports fixed to the layer, respectively.

The support of the separator for a redox flow battery having a current collector function according to the present invention is characterized in that it further comprises a coating layer coated with polyether ether ketone on the surface.

On the other hand, the method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention is a body manufacturing step of manufacturing a body including a carbon felt and having a connection part extending to be exposed to the outside of the flow path frame on one side Wow; and a main body coating step of coating the surface of the connection part with diamond-like carbon (DLC) to form a protective layer.

The method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention includes a fastening hole penetrating the connection part and the protective layer in the thickness direction so that a cable for power extraction can be fastened to the connection part and the protective layer. It characterized in that it further comprises; a fastening groove forming step to form.

The main body manufacturing step of the method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention includes a main layer formed of carbon felt, a first cover layer formed of a conductive resin, and a second cover layer formed of a thermoplastic resin, A preparation step of preparing a plurality of supports each formed of polyethylene and having a coating layer coated with polyether ether ketone on the surface thereof; a support inserting step of inserting the support to a predetermined depth into the main layer through one surface of the main layer; a disposing step of disposing the first cover layer on one side of the main layer and disposing the second cover layer on the other side of the main layer; The first cover layer is heated from the upper part of the first cover layer through the upper thermocompression jig and pressed toward the main layer, and the second cover layer is heated from the lower part of the second cover layer through the lower thermocompression jig. and a thermocompression bonding step of pressing toward the main layer.

In the thermocompression bonding step of the method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention, the coating layers on both ends of the support are drawn into the first cover layer and the second cover layer to a predetermined depth, respectively. It is characterized in that it is compressed or thermally bonded.

The separator for a redox flow battery having a current collector function according to the present invention has a power withdrawal function by forming a connection part capable of connecting a cable for power extraction, and the current collector can be omitted from the stack structure of the existing redox flow battery. In addition, by forming a DLC-coated protective layer on the surface of the connection part to which the cable is connected, the abrasion resistance and friction characteristics of the connection part can be improved.

In addition, the present invention inserts and embeds a support for reinforcement inside the carbon felt, thermocompresses the resin sheet and the carbon felt, and then the separator is deformed or the strength is weakened during cooling. It is easy to handle and there is no deformation even when manufacturing due to the area.

1 is a perspective view of a separator for a redox flow battery having a current collector function according to the present invention.
Figure 2 is an exploded perspective view showing a redox flow battery stack using a separator for a redox flow battery having a current collector function according to the present invention.
3 is a cross-sectional view of a separator for a redox flow battery having a current collector function according to the present invention.
Figure 4 is a cross-sectional view showing the main body manufacturing step of the method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention.
5 is a cross-sectional view showing the body coating step of the method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention.
6 is a cross-sectional view showing a fastening groove forming step of the method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention.
7 to 9 are views showing step-by-step main body manufacturing steps of a method for manufacturing a separator for a redox flow battery having a current collector function according to the present invention according to the present invention.

Hereinafter, the separator 1 for a redox flow battery having a current collector function and a manufacturing method thereof according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show a redox flow battery separator 1 having a current collector function according to the present invention, and FIGS. 4 to 9 show a redox flow battery separator having a current collector function according to the present invention. (1) The manufacturing method is shown.

1 to 3 , the separator 1 for a redox flow battery having a current collector function according to the present invention omits the current collector of the existing redox flow battery, and the function of the current collector is reduced to the separator 1 ), including a main body 1A and a protective layer 1C.

The main body 1A is formed to include carbon felt, and a connecting portion 1B extending to be exposed to the outside of the flow path frame 4 is formed on one side. Unexplained reference numeral '2' in FIG. 2 denotes an electrode disposed on one surface of the separator, and '3' denotes a membrane for ion exchange of the electrolyte.

The protective layer 1C is formed to surround the surface of the connecting portion 1B further extended from the main body 1A to one side in the longitudinal direction of the flow path frame 4 so as to be exposed to the outside of the flow path frame 4 . The protective layer 1C is coated with diamond like carbon (DLC).

And, the connection part (1B) and the protective layer (1C) of the separation plate (1) for a redox flow battery having a current collector function according to the present invention so that the cable for power extraction can be fastened through the fastening bolt (1B) and a fastening hole 1D penetrating the protective layer 1C in the thickness direction is formed. The same coating layer as the protective layer 1C formed on the connection part 1B may be formed on the inner circumferential surface of the fastening hole 1D.

On the other hand, the main body (1A) of the separator (1) for a redox flow battery having a current collector function according to the present invention is a main layer (10), a first cover layer (20), and a second cover layer (30) and , is configured to include a support (40).

The main layer 10 replaces the conventional graphite bulk electrode plate, is formed of carbon felt with internal voids, and has a predetermined thickness and is formed in a rectangular shape.

The first cover layer 20 is bonded by compression or heat to one surface of the opposite surfaces of the main layer 10, and is formed of a conductive resin. The first cover layer 20 may be formed of conductive polyethylene (PE).

The second cover layer 30 is thermally compressed or bonded by heat to the other surface of the main layer 10 on which the first cover layer 20 is compressed or compressed among opposite surfaces of the main layer 10, and is a thermoplastic formed of resin. The second cover layer 30 may be formed of thermoplastic polyethylene (PE).

The support body 40 is embedded in the main layer 10 between the first cover layer 20 and the second cover layer 30, and a plurality of them are embedded in positions spaced apart from each other by a predetermined interval. The support 40 is arranged and embedded in an N×M matrix pattern or a zigzag pattern in the main layer 10 .

The support 40 is formed of polyethylene (PE) and may be formed in a polygonal or cylindrical shape, but in this embodiment, a cylindrical shape is applied.

In addition, the support 40 is further provided with a coating layer 41 coated with polyether ether ketone (PEEK) on the surface.

Polyether ether ketone (PEEK) constituting the coating layer 41 formed on the surface of the support 40 has excellent electrical properties such as electrical insulating dielectric constant and volume resistivity at high temperatures, and can be used without changing physical properties under high temperature and high pressure conditions, It is easily processable using common thermoplastic processing equipment and is a semi-crystalline resin that guarantees excellent stability in a very wide range of inorganic and organic chemicals. In addition, it has excellent lubricity under a wide range of conditions, excellent self-lubrication even in the absence of oil and grease, and excellent wear resistance. In addition, injection molding, extrusion molding, and powder coating are possible, and it is very advantageous not only for mass products but also for the production of small quantity products.

The support 40 has the coating layers 41 at both ends and the opposite ends in the longitudinal direction toward both sides in the thickness direction of the main layer 10, respectively, the first cover layer 20 and the second cover layer 30, respectively, a predetermined depth is drawn into the inside. It is fixed by thermal bonding, thermal compression, or thermal bonding. Alternatively, both ends in the longitudinal direction of the support 40 may be fixed by thermal fusion, thermal compression, or thermal bonding to the surfaces of the first cover layer 20 and the second cover layer 30 , respectively.

On the other hand, although not shown in the drawings, a hollow part may be formed in the longitudinal direction in the inside of the support, and the core part may be formed by filling the hollow part with a filler made of PEEK constituting the coating layer described above, in this case , the support can be further improved in durability and strength by the core part filled in the hollow part.

The separator 1 for a redox flow battery having a current collector function according to the present invention having the structure as described above has a power withdrawal function by forming a connection part 1B capable of connecting a cable for power extraction. The current collector may be omitted from the stack structure of the redox flow battery. In addition, by forming the DLC-coated protective layer 1C on the surface of the connection part to which the cable is connected, it is possible to improve the abrasion resistance and friction characteristics of the connection part.

In addition, the separator (1) for a redox flow battery having a current collector function according to the present invention is a first cover layer (20) on the main layer (10) through a support body (40) provided with a heat-resistant PEEK coating layer (41) And by reinforcing the main layer 10 so that the main layer 10 has a certain thickness by enduring the heat generated during thermocompression bonding or thermal bonding of the second cover layer 30, various thicknesses and areas according to the length of the support body 40 There is an advantage of being able to manufacture the separator 1 having a.

That is, it is possible to manufacture the separator plates 1 of different thicknesses using the supports 40 of different lengths, and even if the main layer 10 is formed of carbon felt, the support body 40 inside the main layer 10 is Since it is embedded and embedded, the main layer 10 is reinforced by the support body 40 to continuously maintain its shape, and there is an advantage in that the separating plate 1 can be manufactured in a large area.

Hereinafter, a method for manufacturing the separator 1 for a redox flow battery having a current collector function according to the present invention as described above will be described with reference to FIGS. 4 to 9 .

4 to 6 , the method for manufacturing a separator 1 for a redox flow battery having a current collector function according to the present invention includes a body manufacturing step, a body coating step, and a fastening hole forming step.

In the body manufacturing step, the body 1A is formed including the carbon felt, and the connection part 1B extended to be exposed to the outside of the flow path frame 4 is formed on one side.

In the coating step, a protective layer 1C is formed by coating the surface of the connection part 1B provided on one side of the body 1A with diamond-like carbon (DLC).

The fastening hole forming step is a fastening hole (1D) penetrating the connecting part (1B) and the protective layer (1C) in the thickness direction through a punching device so that the cable for power extraction can be fastened to the connecting part (1B) and the protective layer (1C). ) to form

The fastening hole forming step may be performed after the body covering step as shown, but may be performed before the body covering step so that the protection layer 1C can also be formed on the inner peripheral surface of the fastening hole 1D.

On the other hand, the main body manufacturing step is shown in Figures 7 to 9. 7 to 9 , the main body manufacturing step is configured to include a preparation step, an insertion step, an arrangement step, and a thermocompression bonding step.

The preparation step includes a main layer 10 formed of carbon felt, a first cover layer 20 formed of a conductive resin, a second cover layer 30 formed of a thermoplastic resin, and a polyether ether ketone formed on the surface of polyethylene. As a step of preparing each of the plurality of supports 40 on which the coated coating layer 41 is formed, which one of the main layer 10, the first cover layer 20, the second cover layer 30, and the support body 40 is first It is free to prepare, and there is no specific order.

In the insertion step, the support 40 prepared in the preparation step is inserted to a predetermined depth into the main layer 10 through one surface of the main layer 10 .

In the arrangement step, the first cover layer 20 is placed on one surface of the main layer 10 , and the second cover layer 30 is placed on the other surface of the main layer 10 .

In the thermocompression bonding step, the first cover layer 20 is heated from the upper portion of the first cover layer 20 through the upper thermocompression bonding jig 50 and pressed to the main layer 10 side, and the second cover layer 30 of It is pressed toward the main layer 10 while heating the second cover layer 30 through the lower thermocompression jig 60 from the bottom.

Through the thermocompression bonding step, the support body 40 is inserted and buried into the main layer 10, and the main layer 10 is compressed in the thickness direction by the upper thermocompression bonding jig 50 and the lower thermocompression bonding jig 60. , the interface between the main layer 10 and the first cover layer 20 and the interface between the main layer 10 and the second cover layer 30 is generated in the upper thermocompression jig 50 and the lower thermocompression jig 60 It is compressed or joined by heat.

In the thermocompression bonding step, one end in the longitudinal direction of the support body 40 facing the first cover layer 20 is softened by the heat generated in the upper thermocompression bonding jig 50 to the inside of the first cover layer 20 to a certain depth. The coating layer 41 of one end in the longitudinal direction of the support 40 that has entered the inside of the first cover layer 20 to a predetermined depth is thermally bonded or thermocompressed to the first cover layer 20 and fixed.

In addition, in the thermocompression bonding step, the other end in the longitudinal direction of the support body 40 facing the second cover layer 30 is softened by the heat generated by the lower thermocompression bonding jig 60 to the inside of the second cover layer 30 . The coating layer 41 of the other end in the longitudinal direction of the support 40 entering a predetermined depth and entering the inside of the second cover layer 30 to a predetermined depth is thermally bonded or thermally compressed to the second cover layer 30 and fixed. do.

The separator for a redox flow battery having a current collector function according to the present invention described above and a manufacturing method thereof have been described with reference to the accompanying drawings, but this is only an example, and those of ordinary skill in the art It will be understood that various modifications and equivalent other embodiments are possible.

Accordingly, the scope of true technical protection of the present invention should be defined only by the technical spirit of the appended claims.

1: Separator
1A: body
1B: connection
1C: protection layer
1D: fastening hole
2: electrode
3: Membrane
4: Euro frame
10: main layer
20: first cover layer
30: second cover layer
40: support
50: upper thermocompression bonding jig
60: lower thermocompression bonding jig

Claims (8)

a body formed including carbon felt and formed with a connection part extending to be exposed to the outside of the flow path frame on one side;
and a protective layer formed to surround the surface of the connection part;
The protective layer is a redox flow battery separator having a current collector function, characterized in that it is coated with diamond-like carbon. According to claim 1,
A separation plate for a redox flow battery having a current collector function, characterized in that the connection part and the protection layer have a fastening hole penetrating the connection part and the protection layer in the thickness direction so that a cable for power extraction can be fastened. 3. The method of claim 2,
The main body includes a main layer formed of the carbon felt, a first cover layer thermocompression bonded to one side of the main layer and formed of a conductive resin, and a second cover layer thermocompression bonded to the other side of the main layer and formed of a thermoplastic resin; , The first cover layer and the second cover layer are respectively buried at positions spaced apart from each other inside the main layer between the first cover layer and the second cover layer, and both ends facing both sides in the thickness direction of the main layer are respectively the first cover layer and the second cover layer A separator for a redox flow battery having a current collector function, characterized in that it comprises a plurality of supports fixed to the. 4. The method of claim 3,
The support is a separator for a redox flow battery having a current collector function, characterized in that it further comprises a coating layer coated with polyether ether ketone on the surface. A main body manufacturing step of manufacturing a body formed including carbon felt and having a connecting portion extending to be exposed to the outside of the flow path frame on one side;
A method of manufacturing a separator for a redox flow battery having a current collector function, characterized in that it comprises; a body coating step of forming a protective layer by coating the surface of the connection part with diamond-like carbon (DLC). 6. The method of claim 5,
The current collector function further comprising; a fastening groove forming step of forming a fastening hole penetrating through the connecting part and the protective layer in a thickness direction so that a cable for power extraction can be fastened to the connecting part and the protective layer. A method for manufacturing a separator for a redox flow battery that combines 6. The method of claim 5,
The body manufacturing step is
A main layer formed of carbon felt, a first cover layer formed of a conductive resin, a second cover layer formed of a thermoplastic resin, and a plurality of supports each formed of polyethylene and having a coating layer coated with polyether ether ketone on the surface. preparation stage;
a support inserting step of inserting the support to a predetermined depth into the main layer through one surface of the main layer;
a disposing step of disposing the first cover layer on one side of the main layer and disposing the second cover layer on the other side of the main layer;
The first cover layer is heated from the upper part of the first cover layer through an upper thermocompression jig and pressed toward the main layer, and the second cover layer is heated from the lower part of the second cover layer through a lower thermocompression jig. and a thermocompression bonding step of pressing toward the main layer. A method for manufacturing a separator for a redox flow battery having a current collector function, characterized in that it comprises a. 8. The method of claim 7,
The thermocompression bonding step is a redox flow battery with a current collector function, characterized in that the coating layers on both ends of the support are drawn to a predetermined depth inside the first cover layer and the second cover layer, respectively, and are thermocompressed or thermally bonded. Separator and method for manufacturing the same.

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