KR102130874B1 - Electrode structure for battery and redox flow battery comprising said electrode - Google Patents

Abstract

The present invention relates to an electrode structure and a redox flow battery comprising the same, and more specifically, a spacer having a through passage or one or more through hole structures, and a plurality of electrode plates positioned before and after the spacer. It relates to an electrode structure comprising and a redox flow battery comprising the same.
Furthermore, the present invention relates to an electrode structure capable of increasing the flow rate and flow rate of the electrolyte between electrodes by a spacer, and thus the output of the battery, and a redox flow battery including the same.

Description

Electrode structure and a redox flow battery comprising the same ELECTRODE STRUCTURE FOR BATTERY AND REDOX FLOW BATTERY COMPRISING SAID ELECTRODE

The present invention relates to an electrode structure and a redox flow battery comprising the same, and more specifically, a spacer having a through passage or one or more through hole structures, and a plurality of electrode plates positioned before and after the spacer. It relates to an electrode structure comprising and a redox flow battery comprising the same.

Furthermore, the present invention relates to an electrode structure capable of increasing the flow rate and flow rate of electrolyte between electrodes by a spacer, thereby increasing the output of the battery, and a redox flow battery including the same.

With the recent signing of the Paris Climate Agreement, renewed energy such as solar power, wind power, and fuel cells has been spotlighted as interest in environmental pollution has increased worldwide. Since renewable energy is greatly affected by the location environment or natural conditions, there is a disadvantage that continuous supply is impossible due to severe output fluctuations, and a large-capacity energy storage technology capable of storing energy at night or under load is highlighted.

The secondary battery that can respond quickly to such a large-capacity energy storage technology is efficient, and the secondary battery includes a lead acid battery, a NaS battery, and a redox flow battery. The lead acid battery is widely used commercially compared to other batteries, but there are problems such as low efficiency and maintenance costs due to periodic replacement and treatment of industrial waste generated during battery replacement. In the case of a NaS battery, it is advantageous in that energy efficiency is high, but there is a problem in that it must be operated at a high temperature of 300°C or higher. Since the redox flow battery has a low maintenance cost, can operate at room temperature, and has the characteristics of independently designing capacity and output, many studies have been conducted with large capacity secondary batteries.

The redox flow battery undergoes ion exchange while circulating the positive electrode and the negative electrode on both sides of the membrane, and in this process, electrons are generated and charged and discharged. Such a redox flow battery is known to be most suitable for an energy storage system because it has a longer life span and can be manufactured as a kW-MW medium and large-sized system compared to a conventional secondary battery.

In addition, the redox flow battery has a structure in which electricity is stored in the electrolyte to repeatedly charge/discharge high-output power over a long period of time, and the redox flow battery needs a high current condition to operate a high-output unit cell. Therefore, a high flow rate and a high flow rate of the electrolyte are required. However, when the flow rate and flow rate of the electrolyte are increased, a pressure drop occurs, and there is a problem in utilization of the active area of the electrode.

In order to solve this problem, a technique has been developed to increase the flow rate and flow rate by forming a flow path having a certain depth in the separator or the electrode.

However, when the flow path is formed in the separator or the electrode, there is an advantage of increasing the flow rate and flow rate of the electrolyte, but there is a problem that the efficiency of the redox flow battery decreases due to an increase in interface resistance between the electrode and the separator.

Therefore, the present inventors have improved the redox flow battery including a separation plate or an electrode formed with an existing flow path to reduce the interface resistance between the electrode and the separator, and to increase the output of the battery by increasing the flow rate and flow rate of the electrolyte of the electrode. It has led to the invention of a structure and a redox flow cell comprising the same.

Korean Patent Publication No. 10-2014-0010711

It is an object of the present invention to increase the flow rate and flow rate of a redox flow battery, an electrode structure comprising a spacer formed through a pair of electrode plates or a spacer having one or more through holes and openings and openings, and a redox flow comprising the same. It is to provide a battery.

In addition, an object of the present invention is to provide an electrode structure and a redox flow battery comprising the same, which increases the surface area where the electrolyte is in contact with the electrode, and improves the performance and efficiency of the electrode as the pair of electrodes is made of heterogeneous materials. .

In order to solve the above problems, the electrode structure according to the present invention is a spacer in which a passage is formed; A first electrode plate located in front of the spacer; And a second electrode plate positioned on the rear surface of the spacer.

In addition, the pierced flow path may be any one of a serpentine type, a parallel type, and an interdigited type.

On the other hand, the electrode structure according to the present invention includes an opening and closing portion; And a through portion through which the electrolyte flows according to the transition state of the opening and closing portion. A first electrode plate located in front of the spacer; And a second electrode plate positioned on the rear surface of the spacer.

In addition, the opening and closing portion and the through portion may be formed repeatedly one or more spaced apart by a predetermined distance along the length and width direction of the spacer.

In addition, the spacer may be made of a conductive material.

In addition, the conductive material may be made of any one of carbon and graphite (graphite).

In addition, the spacer includes a non-conductive structure; And a conductive material coated or bonded to any one or more of front, rear, right, left, upper and lower sides of the non-conductive structure. It can contain.

In addition, the first electrode plate and the second electrode plate may be formed of different kinds of thickness, porosity distribution, porosity, specific surface area, density and conductivity.

In addition, the first electrode plate and the second electrode plate may be formed of any one of carbon felt, carbon paper, carbon fiber, graphite sheet, and carbon nanotube.

On the other hand, a redox flow battery including an electrode structure according to the present invention includes a first electrode and a second electrode, a membrane positioned between the first electrode and the second electrode; A gasket part surrounding the first electrode and the second electrode; A separation plate located outside each of the first electrode and the second electrode; And a flow frame surrounding the periphery of the separation plate.

According to the above-described problem solving means of the present invention, a flow passage formed between the first electrode plate and the second electrode plate is formed, or at least one through hole and a spacer formed with an opening and closing portion are positioned, thereby increasing the active area of the electrode contacting the electrolyte. There is an effect of increasing the output of the battery by increasing the flow rate and flow rate of the electrolyte passing through the electrode.

Furthermore, by placing electrodes formed of felt, paper, or fibers on both sides of the spacer, there is an effect of reducing the interface resistance between the electrode and the separator to increase the efficiency of the redox flow battery.

In addition, since the first electrode plate and the second electrode plate are formed of heterogeneous compositions and structures having different properties, there is an effect of increasing the surface area of the electrolyte contacting the electrode portion and increasing the performance and efficiency of the electrode.

1 is a perspective view showing an electrode structure according to an embodiment of the present invention.
2 is a perspective view showing an electrode structure according to another embodiment of the present invention.
3 is a perspective view showing a unit cell of a redox flow battery including a first electrode and a second electrode according to an embodiment of the present invention.
4 is a perspective view showing a structure of a redox flow battery in which a plurality of unit cells including a first electrode and a second electrode according to an embodiment of the present invention are stacked.

Hereinafter, a preferred embodiment of an electrode structure and a redox flow battery including the same according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition of these terms should be described based on the contents throughout this specification.

1 and 2 are perspective views of the electrode structure 10 according to the present invention. 1A to 1C are perspective views illustrating an electrode structure 10 according to an embodiment of the present invention, and FIGS. 2A to 2C are electrodes according to another embodiment of the present invention. It is a perspective view explaining the structure 10.

3 and 4 are perspective views of the structure of the redox flow battery 100 according to the present invention. 3 is an exploded perspective view showing a unit cell of a redox flow battery including a first electrode and a second electrode according to an embodiment of the present invention, and FIG. 4 is a first electrode according to an embodiment of the present invention, and It is an exploded perspective view showing a redox flow battery in which a plurality of unit cells including a second electrode are stacked.

Referring to FIG. 1, the electrode structure 10 according to the present invention includes a spacer 11 having a through passage formed thereon, a first electrode plate 12 positioned in front of the spacer 11 and a back surface of the spacer 11. It may include a second electrode plate (13) located.

The through passage of the spacer 11 allows the electrolyte flowing around the electrode structure 10 to flow to the front and back of the spacer 11 through the passage, thereby increasing the flow rate of the electrolyte flowing around the electrode, and It has the effect of increasing the active area that the electrolyte can contact.

In addition, the pierced flow path may be formed in any one of a serpentine type, a parallel type, and an interdigited type.

Here, the “shape flow path” means a flow path in which a part of the spacer 11 (that is, a sand shape shape portion) is not penetrated, but a portion excluding the portion is penetrated (see FIG. 1(a)), and “flat flow path” ”Means a flow path in which a part of the spacer 11 (that is, a part of a plurality of straight-line forms that exist in equilibrium with each other) is not penetrated, but a part excluding the part is penetrated (see FIG. 1 (b)), In addition, it is noted that the “engagement type flow path” means a flow path in which a part of the spacer 11 (that is, a part in which the U-shape is spaced apart from each other) is not penetrated, but a part excluding the part is penetrated (FIG. 1 (c)).

Meanwhile, referring to FIG. 2, the electrode structure 10 ′ according to the present invention includes a spacer 11 ′ including an opening part 1 and a through part 2 through which electrolyte flows according to a transition state of the opening part 1. , The first electrode plate 12 positioned on the front of the spacer 11' and the second electrode plate 13 positioned on the rear of the spacer 11'.

At this time, the opening and closing portion 1 is connected to one surface of the through portion 2 to control the flow rate and flow rate of the electrolyte. For example, when connected to the top of the opening and closing portion 1 and the through portion 2, both sides and bottom of the opening and closing portion 1 are separated from the through portion 2, so that the electrolyte is front and rear of the spacer 11' Can be flowed into. Furthermore, it can be noted that one or more of the opening/closing portion 1 and the through portion 2 may be repeatedly formed while being spaced apart by a predetermined distance along the length and width direction of the spacer 11'.

At this time, the opening/closing portion 1 may have the same separation direction along the lateral direction, for example, the opening/closing portion 1 of the first row protrudes to the front of the spacer 11', and the flow path is opened, and the second row is opened. The silver spacer 11 protrudes to the rear surface of the spacer 11 to open.

However, the protruding direction of the opening/closing part 1 is not limited to this, and both of the spacers 11' protrude in one of the front and rear surfaces to open the flow path, or the opening/closing part 1 protrudes according to the longitudinal direction. The directions can be formed the same.

In addition, as a method of forming the opening/closing part 1 and the through hole 2 in the spacer 11', a method in which the edge is cut by a punching or sharp member may be applied except for a part of the through hole 2, Note that various known technologies can be applied instead of these methods.

By forming a passage or a through hole 2 through the spacers 11 and 11', the electrolyte absorbed by the first electrode plate 12 or the second electrode plate 13 passes through the flow passage of the electrode structure 10. As it is transferred to the front and rear surfaces, the active area of the electrode structure 10 increases, and the flow rate and flow rate of the electrolyte increase, thereby suppressing pressure drop.

The spacers 11 and 11' may be made of a conductive material. The conductive material is not limited as long as it is a material used for the electrode structure, but is preferably made of any one of carbon and graphite.

Meanwhile, the spacers 11 and 11' are conductive materials (not shown) that are coated or bonded to any one or more of the non-conductive structure (not shown) and the front, rear, right, left, upper, and lower sides of the non-conductive structure, respectively. Note that may include). That is, the flow paths formed through the non-conductive structure portion serving to form the basic shape of the spacers 11 and 11' are formed, and the serpentine-shaped portions, a plurality of straight-shaped portions, and the U-shaped shapes are spaced apart from each other. The spacers 11 and 11' may have conductivity by coating or bonding the conductive material on the front and rear surfaces of the portion between the engaged portions, the opening/closing portion 1 and the spaced through-hole 2.

In addition, since the non-conductive structure is made of a non-corrosive and chemical-resistant material, a flow path and a through hole 2 are easily formed, and it is suitable to be applied to a system using a strong acidic material as an electrolyte, and has an effect of increasing mechanical properties. .

A mold may be used as a method of forming the through passages of the spacers 11 and 11'. For example, a conductive material, a non-conductive structure, and a conductive material are stacked on a mold having a flow path formed thereon, and by pressing the mold at a high temperature, a conductive material is applied to any one of the front, rear, right, left, upper, and lower sides of the non-conductive structure. The bonded spacers 11 and 11' can be manufactured. At this time, it should be noted that the non-conductive structure to be laminated and the conductive material can be laminated in the form of powder, resin or plate. In addition, the non-conductive structure may include any one or more of polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and polystyrene (PS), but as long as it contains a non-conductive material used in the art Note that the composition is not limited.

Moreover, conductive materials include solution coating, sputtering, vacuum thermal vapor deposition, atomic layer deposition (ALD), chemical vapor deposition (CVD), pasting, doctor-blading, web coating, It can be coated on any one or more of the front, rear, right, left, upper and lower sides of the non-conductive structure 110 using any one or more of rolling, screen printing, solution casting, spray deposition and dipping processes. Note that it is not limited as long as it includes the coating or bonding method used in the.

The first electrode plate 12 and the second electrode plate 13 are located on the front and back surfaces of the spacers 11 and 11', respectively, so that the electrode structures 10 and 10' are formed of a multi-layer structure composed of two or more layers. Can.

At this time, the first electrode plate 12 and the second electrode plate 13 can have the same pole, and the first electrode plate 12 and the second electrode plate 13 have a thickness, a porosity distribution, Porosity, specific surface area, density and conductivity may be formed of different species.

For example, the first electrode plate 12 is formed of a high-density composition having a large specific surface area, and the second electrode plate 13 is formed of a low-density composition having a relatively small specific surface area, whereby the chemical reaction is concentrated. While providing a sufficient reaction site, the flow resistance of the electrolyte can be lowered by allowing the electrolyte to flow easily in a portion where the chemical reaction is not concentrated. At this time, it is noted that a high-efficiency electrode plate is disposed near the membrane 40 where the reaction is concentrated, and a low-efficiency electrode plate is disposed near the separation plate 60 having a relatively low ion density.

Alternatively, the first electrode plate 12 improves the size and porosity of the pores, thereby improving the rate and inflow of the electrolyte into the electrode structures 10 and 10' through the first electrode plate 12, thereby increasing the electrode structure. (10, 10') increases the effective reaction surface area where electrochemical reactions can occur inside, and the second electrode plate 13 increases the specific surface area, thereby increasing the electrical conductivity of the second electrode plate 13 to increase the cell Can maximize performance and efficiency.

In addition, the first electrode plate 12 and the second electrode plate 13 are not limited as long as they can be used as electrodes of the battery, but any of carbon felt, carbon paper, carbon fiber, graphite sheet, and carbon nanotubes It is preferably formed as one.

Meanwhile, referring to FIGS. 3 and 4, a structure of the redox flow battery 100 in which the above-described electrode structure is applied as the first electrode 20 and the second electrode 30 is illustrated. More specifically, the redox flow battery 100 includes a first electrode 20, a second electrode 30, a membrane 40 positioned between the first electrode 20 and the second electrode 30, and Gasket portion 50 surrounding the periphery of the first electrode 20 and the second electrode 30, the separation plate 60 and the separation plate 60 located on one side of the first electrode 20 and the second electrode 30 ) May include a flow frame 70 surrounding the periphery.

At this time, when the first electrode 20 is an anode, the second electrode 30 may be formed as a cathode, or when the first electrode 20 is a cathode, the second electrode 30 may be formed as an anode. . In addition, by the spacer 11 included in the first electrode 20 and the second electrode 30, the flow rate and flow rate of the electrolyte contacting each of the membrane 40 and the separation plate 60 are increased, and accordingly , The output amount of the redox flow battery 100 may also be increased.

In addition, the membrane 40 is an ion exchange membrane that is generally used in secondary batteries, and selectively serves as a separation membrane that transmits ions. By exchanging metal ions through the membrane 40, a redox reaction between the electrodes of the positive electrode and the negative electrode can be achieved.

The gasket portion 50 is generally configured between the membrane 40 and the electrode. In the present invention, when stacking unit cells of a redox flow battery, the first electrode 20 or the second electrode 30 and the separation plate ( Note that it is possible to prevent leakage of electrolyte while maintaining the interval of 60).

Furthermore, the separation plate 60 may generally serve to disconnect the positive and negative electrolytes. The separation plate 60 may be formed of one of a bipolar plate and a monopolar plate. For example, referring to FIG. 4, when the separation plate 60 is a monopolar plate, the redox flow battery 100 is stacked. The order may be a separator 60, an anode, a membrane 40, a cathode, a separator 60, a cathode, a membrane 40, an anode, a separator 60. In addition, when the separation plate 60 is a bipolar plate, the stacking order of the redox flow battery 100 is the separation plate 60, the anode, the membrane 40, the cathode, the separation plate 60, the anode, the membrane 40 ), the cathode, may be a separator (60).

In addition, when the separation plate 60 included in the redox flow battery 100 is a monopolar plate, a flow passage through the separation plate 60 may be formed to increase the output amount.

In addition, the first separation plate and the last separation plate of the redox flow battery 100 may serve as a current collector. That is, when the separation plate serves as a current collector, the current collector may be omitted. The current collector may serve to collect electrons generated by the electrochemical reaction of the active material or supply electrons necessary for the electrochemical reaction. Further, it may serve as a passage through which the electrode electrolyte in which the electrochemical reaction has occurred flows into the tank or the electrode electrolyte stored in the tank flows into the electrode portion.

The flow frame 70 is configured between the first electrode 20 and the first electrode 20 or between the first electrode 20 and the second electrode 30, and the separation plate 60 is a monopolar plate. In one case, the spacing between the first electrode 20 and the first electrode 20 is maintained, and when the separation plate 60 is a bipolar plate, the spacing between the first electrode 20 and the second electrode 30 is maintained. By doing so, there is an effect of reducing the phenomenon that the electrolyte passes over the separator plate 60.

Additionally, although not shown, the redox flow battery 100 is connected to a tank for storing a battery electrolyte in which an electrochemical reaction has not occurred, a tank and a separator 60, and is formed in pipes and pipes through which the electrode electrolyte moves, A pump for introducing and discharging the electrode electrolyte may be included. In detail, the electrode electrolyte is introduced and discharged from the redox flow battery 100 into the tank by driving the pump, so that the electrode electrolyte stored in the tank may circulate between the tank and the redox flow battery 100. At this time, the pump may be located in the pipe through which the electrode electrolyte moves between the separation plate 60 and the tank.

Although described above with reference to preferred embodiments of the present invention, those skilled in the art variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below and You will understand that you can change it.

1: opening and closing part
2: Through hole
10, 10': electrode structure
11, 11': spacer
12: first electrode plate
13: second electrode plate
20: first electrode
30: second electrode
40: membrane
50: gasket part
60: separation plate
70: flow frame
100: redox flow battery

Claims (11)

A spacer through which a passage is formed and made of a conductive material;
A first electrode plate located in front of the spacer; And
Characterized in that it comprises; a second electrode plate located on the back of the spacer;
Electrode structure.
According to claim 1,
The through passage,
Characterized in that the shape of any one of a serpentine type, a parallel type, and an interdigited type,
Electrode structure.
draw; And a through portion through which the electrolyte flows according to a transition state of the opening and closing portion.
A first electrode plate located in front of the spacer; And
Characterized in that it comprises; a second electrode plate located on the back of the spacer;
Electrode structure.
According to claim 3,
The opening and closing portion, the through portion,
Characterized in that one or more repeatedly formed while being spaced a predetermined distance along the length and width direction of the spacer,
Electrode structure.
According to claim 3,
The spacer,
Characterized in that it is made of a conductive material,
Electrode structure.
According to any one of claims 1 and 5,
The conductive material,
Characterized in that it is made of any one of carbon and graphite (graphite),
Electrode structure.
According to claim 3,
The spacer,
Non-conductive structure; And
Characterized in that it comprises; conductive material that is coated or bonded to any one or more of the front, rear, right, left, upper and lower sides of the non-conductive structure;
Electrode structure.
A spacer comprising a non-conductive structure and a conductive material coated or bonded to any one or more of the front, rear, right, left, upper, and lower sides of the non-conductive structure and the non-conductive structure;
A first electrode plate located in front of the spacer; And
Characterized in that it comprises; a second electrode plate located on the back of the spacer;
Electrode structure.
The method of any one of claims 1, 3 and 8,
The first electrode plate and the second electrode plate,
Characterized in that the thickness, porosity distribution, porosity, specific surface area, density and conductivity are formed of different types,
Electrode structure.
The method of any one of claims 1, 3 and 8,
The first electrode plate and the second electrode plate,
Characterized in that it is formed of any one of carbon felt, carbon paper, carbon fiber (cloth), graphite sheet and carbon nanotubes,
Electrode structure.
The electrode structure according to any one of claims 1, 3, and 8 is included as a first electrode and a second electrode, respectively.
A membrane positioned between the first electrode and the second electrode;
A gasket part surrounding the first electrode and the second electrode;
A separation plate located outside each of the first electrode and the second electrode; And
Characterized in that it comprises a; flow frame surrounding the separation plate;
Redox flow battery.

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