KR20210066649A - Separator for Redox Flow Battery and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a separator for a redox flow battery using a polymer resin, and a manufacturing method thereof, which can reinforce a part which is deformed or has weakened or become vulnerable from losing strength during separation after cooling by coupling a carbon felt and a thermoplastic resin sheet in a thermal compression or thermal bonding method by replacing a conventional separator of a graphite bulk-type. The separator for a redox flow battery of the present invention can reinforce a part that a separator is deformed or has weakened or become vulnerable from losing strength during cooling after a resin sheet and a carbon felt are thermally compressed by inserting and burying a support for reinforcement into the carbon felt, is easily handled and is not deformed even when being manufactured as a large area.

Description

Separator for Redox Flow Battery and Manufacturing Method Thereof using Polymer Resin

The present invention relates to a separator for a redox flow battery using a polymer resin and a method for manufacturing the same, and more particularly, by replacing the conventional graphite bulk type separator by thermocompression bonding or thermal bonding between carbon felt and a thermoplastic resin sheet. It relates to a separator for a redox flow battery using a polymer resin capable of preventing deformation during separation after cooling by bonding and reinforcing a portion with reduced strength or weak strength, and a method for manufacturing the same.

The redox flow battery is one of the core products closely related to new and renewable energy, greenhouse gas reduction, secondary battery, and smart grid, which are drawing the greatest interest in the world recently, and fuel cells are fossil fuel cells without emitting environmental pollutants. As a new and renewable energy source to replace fuel, it is a product that is rapidly expanding its market worldwide. Currently, most energy is obtained from fossil fuels, but the use of such fossil fuels has a serious adverse effect on the environment, such as air pollution, acid rain, and global warming, and has low energy efficiency.

In recent years, interest in renewable energy and fuel cells has rapidly increased in order to solve the problems associated with the use of fossil fuels. Interest in and research on these new and renewable energy is being actively conducted not only in Korea but also around the world.

Although the renewable energy market is said to have entered the maturity stage at home and abroad, there is a problem that the amount of energy generated varies greatly depending on environmental influences such as time and weather due to the nature of renewable energy. The distribution of an energy storage system (ESS) for storing the generated renewable energy is very necessary, and it is a redox flow battery that is attracting attention as such a large-capacity energy storage system.

The general structure of a redox flow battery consists of a stack in which cells in which an electrochemical reaction occurs, a tank for storing electrolytes, and a pump supplying electrolytes from the electrolyte tank to the stack.

The general stack structure of a redox flow battery is end plate-insulation plate-current collector plate-separator-gasket-flow frame-electrode-gasket-ion exchange membrane-gasket-electrode-flow frame-gasket-separator-collector plate-insulation plate-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.

Recently, for the application of tens of MWh class ESS, it is essential to increase the area of the redox flow battery and increase the output through high current density operation, and a large-area bipolar plate is required for the large area of the redox flow battery.

In relation to the separator plate of the redox flow battery, US Patent No. 6656639 discloses a technology for integrating electrodes disposed on both sides of the separator plate into the separator plate, and the Republic of Korea Utility Model No. 20-0463822 provides durability maintenance and easy manufacturing. A bipolar plate for a redox flow cell is shown.

However, in the above Republic of Korea registered utility model, when the published bipolar plate is enlarged, the distance between the electrolyte supply line and the electrolyte discharge line increases, so that the larger the bipolar plate, the more severe the concentration deviation occurs. There is a very difficult problem to handle.

In the case of the above U.S. patent, since it is manufactured by thermocompression bonding the electrode and the resin sheet, the resin sheet in the portion not in contact with the electrode is heated, and the residual stress at the boundary between the portion in contact with the electrode and the portion not in contact during the cooling process There is a problem in that the separation plate is deformed or the strength is weakened when the jig is separated.

KR20-0463822Y1 KR10-2017-0113120A US6656639B1

The present invention is to solve the conventional problems as described above, and after thermocompression bonding a thermoplastic resin sheet, which is a separator material, between an electrode and an electrode, a polymer resin capable of improving the problem that the separator is deformed or the strength is weakened during cooling An object of the present invention is to provide a separator for a redox flow battery using

In addition, the present invention forms a reinforcing structure in a region where the strength of the thermoplastic resin sheet may become weak in the process of thermocompression bonding between the electrode and the thermoplastic resin sheet, so that the separation plate can be enlarged and a polymer resin capable of reinforcing strength is produced. An object of the present invention is to provide a separator for a redox flow battery and a method for manufacturing the same.

In addition, the present invention provides a separator for a redox flow battery using a polymer resin capable of bonding carbon felt and a thermoplastic resin sheet by thermocompression bonding or thermal bonding by replacing the conventional graphite bulk type separator and a method for manufacturing the same It is intended to

A separator for a redox flow battery using a polymer resin according to the present invention for achieving the above object includes: a main layer formed of carbon felt; a first cover layer thermocompression-bonded to one surface of the main layer and formed of a conductive resin; a second cover layer thermocompression-bonded to the other surface of the main layer and formed of a thermoplastic resin; The first cover layer and the second cover layer are respectively embedded at positions spaced apart from each other inside the main 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. It is characterized in that it is provided with a plurality of supports fixed to.

The support of the separator for a redox flow battery using a polymer resin according to the present invention is formed of polyethylene and is characterized in that it is formed in a polygonal or cylindrical shape.

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

The support of the separator for a redox flow battery using the polymer resin according to the present invention is characterized in that the coating layers on both ends of the support are inserted and fixed to a predetermined depth inside the first cover layer and the second cover layer, respectively. .

On the other hand, the method for producing a separator for a redox flow battery using a polymer resin according to the present invention for achieving the above object is a main layer formed of carbon felt, a first cover layer formed of a conductive resin, and a second formed of a thermoplastic resin A preparation step of preparing a cover layer and 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 using a polymer resin according to the present invention, the coating layers on both ends of the support are drawn to a predetermined depth into the first cover layer and the second cover layer, respectively. Or it is characterized by thermal bonding.

The separator for a redox flow battery using a polymer resin according to 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 or strength The weak part can be reinforced, and it has the advantage of being easy to handle and not deformed even during manufacturing with a large area.

1 is an exploded perspective view of a separator for a redox flow battery using a polymer resin according to the present invention.
2 is a cross-sectional view of a separator for a redox flow battery using a polymer resin according to the present invention.
3 is a flowchart showing a method for manufacturing a separator for a redox flow battery using a polymer resin according to the present invention.
4 to 6 are cross-sectional views showing a method for manufacturing a separator for a redox flow battery using a polymer resin according to the present invention.

Hereinafter, a separator for a redox flow battery using a polymer resin according to a preferred embodiment of the present invention and a manufacturing method thereof will be described in detail with reference to the accompanying drawings.

1 and 2 show a separator for a redox flow battery using a polymer resin according to the present invention, and FIGS. 3 to 6 show a method for manufacturing a separator for a redox flow battery using a polymer resin according to the present invention. .

1 and 2, the separator 1 for a redox flow battery using a polymer resin according to the present invention is formed by compressing or bonding a conductive resin and a thermoplastic resin to an electrode plate using heat, and the main layer (10), a first cover layer (20), a second cover layer (30), and a support body (40).

The main layer 10 of the separator plate 1 for a redox flow battery using a polymer resin according to the present invention replaces the existing graphite bulk electrode plate, and is formed of carbon felt with internal voids, and has a certain thickness and is rectangular. is formed with

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 using a polymer resin according to the present invention having the structure as described above is a first cover on the main layer 10 through the support 40 provided with a PEEK coating layer 41 that is resistant to heat. According to the length of the support body 40 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 layer 20 and the second cover layer 30 There is an advantage in that it is possible to manufacture separators having various thicknesses and areas.

That is, it is possible to manufacture separator plates of different thicknesses using the supports 40 of different lengths, and even if the main layer 10 is formed of carbon felt, the support 40 is inserted and buried inside the main layer 10. The main layer 10 is reinforced by the support 40 so that its shape can be continuously maintained, and there is an advantage in that the separation plate can be manufactured in a large area.

Hereinafter, a method for manufacturing the separator 1 for a redox flow battery using the polymer resin according to the present invention as described above will be described with reference to FIGS. 3 to 6 .

3 to 6, the method for manufacturing a separator 1 for a redox flow battery using a polymer resin according to the present invention includes a preparation step (S10), an insertion step (S20), an arrangement step (S30), It is configured to include a thermocompression bonding step (S40).

In the preparation step (S10), the main layer 10 formed of carbon felt of the separator 1 for a redox flow battery using the polymer resin according to the present invention described above with reference to FIGS. 1 and 2, and the first formed of a conductive resin Preparing the cover layer 20, the second cover layer 30 formed of a thermoplastic resin, and a plurality of supports 40 formed of polyethylene and having a coating layer 41 coated on the surface with polyether ether ketone, respectively As such, any one of the main layer 10, the first cover layer 20, the second cover layer 30, and the support body 40 may be prepared first, and there is no specific order.

In the insertion step (S20), the support body 40 prepared in the preparation step (S10) is inserted to a predetermined depth into the main layer 10 through one surface of the main layer 10 .

In the arrangement step (S30), the first cover layer 20 is disposed on one surface of the main layer 10, and the second cover layer 30 is disposed on the other surface of the main layer 10.

In the thermocompression bonding step (S40), 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) is pressed toward the main layer 10 while heating the second cover layer 30 through the lower thermocompression jig 60 in the lower part.

Through the thermocompression bonding step (S40), the support body 40 is inserted and buried into the main layer 10, and the main layer 10 is formed by the upper thermocompression bonding jig 50 and the lower thermocompression bonding jig 60 in the thickness direction. and 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 an upper thermocompression jig 50 and a lower thermocompression jig 60 ) is compressed or bonded by the heat generated in the

In the thermocompression bonding step (S40), one end of the longitudinal direction of the support body 40 facing the first cover layer 20 is softened by the heat generated in the upper thermocompression jig 50. The inner side of the first cover layer 20 The coating layer 41 of one end in the longitudinal direction of the support 40 entered to a predetermined depth into the inner side of the first cover layer 20 is thermally bonded or thermally compressed to the first cover layer 20. is fixed

In addition, in the thermocompression bonding step (S40), the other end of the longitudinal direction of the support 40 facing the second cover layer 30 is softened by the heat generated in the lower thermocompression bonding jig 60 second cover layer 30) The coating layer 41 of the other end in the longitudinal direction of the support 40 entering a predetermined depth into the inside of the second cover layer 30 and entering the inside of the second cover layer 30 is thermally bonded or thermally bonded to the second cover layer 30 . pressed and fixed.

Meanwhile, although not shown in the drawings, the method for manufacturing the separator 1 for a redox flow battery using a polymer resin according to the present invention may be manufactured in a different order from that described with reference to FIGS. 3 to 6 .

For example, in the method for manufacturing the separator 1 for a redox flow battery using a polymer resin according to another embodiment of the present invention, a lower thermocompression bonding jig 60 is prepared, and a second cover on the lower thermocompression bonding jig 60 . Laying the layer 30, arranging a plurality of supports 40 on the second cover layer 30 in a predetermined pattern, stacking the main layer 10 on the supports 40, the main layer 10 ) on the first cover layer 20, and after placing the upper thermocompression bonding jig 50 on the upper part of the first cover layer 20, the upper thermocompression bonding jig 50 and the lower thermocompression bonding jig 60 ) through, while heating the first cover layer 20 and the second cover layer 30, the upper thermocompression bonding jig 50 and the lower thermocompression bonding jig 60 may be manufactured by a method of pressing toward each other.

The separator for a redox flow battery using the polymer resin according to the present invention described above and a method for manufacturing the same have been described with reference to the accompanying drawings, but this is only an example, and those of ordinary skill in the art can use various It will be understood that 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
10: main layer
20: first cover layer
30: second cover layer
40: support
50: upper thermocompression bonding jig
60: lower thermocompression bonding jig

Claims (6)

a main layer formed of carbon felt;
a first cover layer thermocompression-bonded to one surface of the main layer and formed of a conductive resin;
a second cover layer thermocompression-bonded to the other surface of the main layer and formed of a thermoplastic resin;
The first cover layer and the second cover layer are respectively embedded 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 using a polymer resin, characterized in that it comprises a plurality of supports fixed to the. According to claim 1,
The support is formed of polyethylene, and a separator for a redox flow battery using a polymer resin, characterized in that it is formed in a polygonal or cylindrical shape. 3. The method of claim 2,
The support is a separator for a redox flow battery using a polymer resin, characterized in that it further comprises a coating layer coated with polyether ether ketone on the surface. 4. The method of claim 3,
The support is a redox flow battery separator using a polymer resin, characterized in that the coating layers on both ends of the support are inserted and fixed to a predetermined depth inside the first cover layer and the second cover layer, respectively. 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 using a polymer resin, comprising: a. 6. The method of claim 5,
The thermocompression bonding step is a redox flow battery separation using a polymer resin, 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. plate.

Images