KR102011764B1 - Flow battery and battery module comprising thereof - Google Patents

Abstract

The present specification relates to a flow battery and a battery module including the same.

Description

FLOW BATTERY AND BATTERY MODULE COMPRISING THEREOF}

The present specification relates to a flow battery and a battery module including the same.

Electric power storage technology is an important technology for efficient use of the entire energy, such as efficient use of electric power, improvement of the power supply system's ability and reliability, the introduction of renewable energy that fluctuates over time, and the energy regeneration of the moving body. There is an increasing demand for possibilities and social contributions.

Adjusting the supply and demand balance of semi-autonomous regional power supply systems such as microgrids and properly distributing non-uniform outputs of renewable energy generation such as wind and solar power, and voltage and frequency fluctuations resulting from differences from existing power systems. In order to control the effect of the secondary battery is being actively researched and the expectation of the utilization of the secondary battery in these fields is increasing.

When looking at the characteristics required for the secondary battery to be used for large-capacity power storage, the energy storage density should be high, and flow batteries are the most popular as high-capacity and high-efficiency secondary batteries most suitable for these characteristics.

The flow battery is configured such that the electrodes of the positive electrode and the negative electrode are positioned at both sides of the separator. A bipolar plate for electric conduction is provided on the outside of the electrode, and includes a positive electrode tank and a negative electrode tank for holding the electrolyte, an inlet for the electrolyte to enter the electrode, and an outlet for the electrolyte to come back.

Korean Patent Publication No. 2009-0046087

The present specification is to provide a flow battery and a battery module including the same.

Herein is a cathode and an anode; A cathode tank and an anode tank for storing a cathode electrolyte or a cathode electrolyte, respectively; A cathode inflow path provided to allow the anode electrolyte to flow into the cathode from the anode tank; A cathode discharge passage provided to discharge the cathode electrolyte from the cathode to the anode tank; An anode inflow path provided to allow the anode electrolyte to flow into the cathode from the anode tank; An anode discharge passage provided to discharge the anode electrolyte from the anode to the anode tank; And it provides a flow battery comprising an opening and closing portion provided in at least one of the cathode inlet, cathode outlet, anode inlet and anode outlet.

In addition, the present disclosure provides a battery module including the flow battery as a unit cell.

The flow battery according to the exemplary embodiment of the present specification may reduce the influence of shunt current when manufacturing the unit cell and the stack.

The flow battery according to one embodiment of the present specification may prevent backflow of the electrolyte.

The flow battery according to the exemplary embodiment of the present specification may prevent the electrolyte in the electrode cell and the stack from being deteriorated during non-operation.

1 is a cross-sectional view showing a general structure of a flow battery.
FIG. 2 is an enlarged view of region 'a' of FIG. 1.
3 is a view illustrating a state in which a valve-shaped opening and closing part is provided according to an exemplary embodiment of the present specification, and a change in the valve-shaped opening and closing part according to the flow of an electrolyte.
4 is a view illustrating a state in which a watermill-type opening and closing part is provided according to an exemplary embodiment of the present specification, and a change in the watermill-type opening and closing part according to the flow of an electrolyte.

Hereinafter, the present specification will be described in detail.

Herein is a cathode and an anode; A cathode tank and an anode tank for storing a cathode electrolyte or a cathode electrolyte, respectively; A cathode inflow path provided to allow the anode electrolyte to flow into the cathode from the anode tank; A cathode discharge passage provided to discharge the cathode electrolyte from the cathode to the anode tank; An anode inflow path provided to allow the anode electrolyte to flow into the cathode from the anode tank; An anode discharge passage provided to discharge the anode electrolyte from the anode to the anode tank; And it provides a flow battery comprising an opening and closing portion provided in at least one of the cathode inlet, cathode outlet, anode inlet and anode outlet.

1 is a cross-sectional view illustrating a general structure of a flow battery, and FIG. 2 is an enlarged view of region 'a' of FIG. 1. 1 and 2, the flow battery includes a cathode 21 and an anode 22; A cathode inlet 41 and an anode inlet 42 respectively introduced into the cathode 21 or the anode 22; A cathode discharge passage 31 and a cathode discharge passage 32 through which the electrolyte is discharged from the cathode 21 or the anode 22 are included.

Flow battery according to the present disclosure is at least one of the negative electrode inlet 41, the negative electrode inlet 31, the positive electrode inlet 42 and the positive electrode outlet 32 in the cross-sectional view of the flow battery shown in FIG. It includes an opening and closing portion provided in the interior.

The opening and closing unit may be provided in at least one of the negative electrode inlet, the negative electrode outlet, the positive electrode inlet and the positive electrode of the flow battery. In this case, the shunt current can be reduced in the electrode.

In the present specification, the shunt current refers to a case in which a fine current flows on a material having low resistance.

Basically, the current generated inside the electrode should flow to the outside through the electrode and the current collector, and when the current flows through the electrolyte instead of the outside, the shunt current is generated. As the shunt current increases, the current loss increases and the efficiency of the battery Is lowered.

Specifically, in a flow battery having a passage for supplying and discharging an electrolyte to an electrode, an electrolyte having an electrolyte that does not flow into the electrode, that is, a part far from the electrode, that is, does not flow into the electrode and the current collector, instead of flowing into the electrode and the current collector. The microcurrent flowing in the inflow path and the electrolyte discharge path with the electrolyte discharged away from the inside of the electrode is called a shunt current.

1 and 2, the negative electrode inlet passage 41, the negative electrode outlet passage 31, the positive electrode inlet passage 42 and the positive electrode outlet passage 32, which are passages for supplying and discharging electrolyte to the electrode, are shown in FIGS. At this time, a microcurrent may flow along the electrolyte away from the electrode.

In the present specification, when the opening and closing portion is provided in at least one of the negative electrode inflow path, the negative electrode discharge path, the positive electrode inflow path and the positive electrode discharge path of the flow battery, the generation of a shunt current in the electrode can be reduced, and as a result, the current It can prevent the loss and increase the efficiency of the battery.

In the present specification, at least one of the negative electrode inlet, the positive electrode inlet, the positive electrode inlet, and the positive electrode inlet of the flow battery may be provided with an opening and closing unit. In this case, it is possible to minimize the shunt current in the electrode and prevent the electrolyte from flowing back from the electrode to the cathode inlet and the anode inlet.

The opening and closing unit may be provided inside the cathode inlet, the anode outlet, the anode inlet and the anode outlet of the flow battery. In this case, it is possible to minimize the shunt current in the electrode and to prevent the backflow of the electrolyte from the electrode to the cathode inlet, the cathode outlet, the anode inlet and the anode outlet, and to prevent the electrolyte inside the electrode from deteriorating during non-operation. You can prevent it.

According to the exemplary embodiment of the present specification, when the opening and closing portion is provided in at least one of the cathode inflow passage, the cathode discharge passage, the anode inflow passage, and the anode discharge passage, the electrode in the interior of the inflow passage or the discharge passage provided with the opening and closing portion It is preferable that the opening and closing portion is located at the end connected to the.

For example, as illustrated in FIGS. 3 and 4, openings 100 and 200 may be provided at ends of the cathode inflow passage 41 that are connected to the electrodes.

Specifically, the opening and closing portion is the end of the inside of the negative electrode inlet connected to the negative electrode; An end portion connected to the cathode in the cathode discharge path; An end portion connected to the anode in the anode inflow path; And an end connected to the anode in the anode discharge path.

In the present specification, the opening and closing part refers to a member capable of repeating the opening and closing of the inlet provided according to the conditions. The opening and closing part may be opened when the electrolyte flows and closed when the electrolyte does not flow.

Specifically, the electrolyte flows by the pump, and at this time, the electrolyte may pass through the opening and closing part by the force generated at the speed at which the electrolyte flows. As the flow rate of the electrolyte decreases, the force that the electrolyte pushes the opening and closing portion decreases, thereby decreasing the amount of the electrolyte passing through the opening and closing portion. If the electrolyte does not flow, the electrolyte may not pass through the opening because there is no force to push the opening or closing portion or the force to push the opening can not move the opening.

The opening and closing material may be a material having a high chemical resistance to the solvent and the electrolyte in the strong acid and the electrolyte. The material of the opening and closing part is not particularly limited as long as it is chemically resistant to a solvent and an electrolyte in the strong acid and the electrolyte.

For example, polyacrylate, polyethylene (PE, polyethylene), polypropylene (PP, polypropylene), polyethylene terephthalate (PET), polyethylene ether phthalate, polyethylene phthalate ), Polybuthylene phthalate (polybuthylene phthalate), polyethylene naphthalate (PEN; Polyethylene Naphthalate), polycarbonate (PC; polycarbonate), polystyrene (PS, polystyrene), polyether imide, polyether sulfone ), Polydimethyl siloxane (PDMS), polyether ether ketone (PEEK; Polyetheretherketone), polyimide (PI; polyimide), polyvinylidene fluoride (PVDF, polyvinylidene fluoride), polytetrafluoroethylene (PTFE, Polytetrafluoroethylene) A single polymer of at least one of polyurethane, silicone resin and polyketone, From the group consisting of a mixture or two or more copolymers may include a material of one type selected.

The shape of the opening and closing portion is not limited as long as it can be repeated to open and close the passage provided according to the condition, for example, it may be at least one of the valve type and the watermill.

According to one embodiment of the present specification, the opening and closing portion may be at least one of a valve shape and a watermill shape. The shape of the opening and closing portion may be different or the same according to the position at which the opening and closing portion is installed.

According to an exemplary embodiment of the present specification, the opening and closing portion may be a valve shape.

The valve-shaped opening and closing part is provided inside at least one of a cathode inflow path, a cathode discharge path, an anode inflow path, and an anode discharge path, and when provided, one end of the valve opening is fixed inside the passage. Specifically, a part of the edge or side surface of the valve-shaped opening and closing portion is fixed to the inside of the passage.

For example, as shown in Figure 3, when the valve-shaped opening and closing portion 100 is provided in the inlet or outlet, one end of the valve-shaped opening and closing portion 100 is fixed to the inside of the passage.

When the electrolyte does not flow, the electrolyte is not able to pass through the valve-shaped opening part because a portion of the end portion of the valve-shaped opening part that is not fixed to the passage is fitted in the inner wall of the passage.

When the electrolyte flows, one end of the valve-shaped opening / closing portion fixed to the inside of the passage is not moved and the portion which is not fixed to the inside of the passage is pushed by the flowing electrolyte, separated from the inner wall of the passage, and the valve-shaped opening / closing portion is bent. The electrolyte may pass through the opening and closing part. At this time, the faster the flow rate of the electrolyte, the more the valve-shaped opening and closing portion, and consequently the amount of the electrolyte passing through the valve-shaped opening and closing may be increased.

Specifically, as shown in FIG. 3, when the flow A of electrolyte occurs, a portion of the end portion of the valve-shaped opening / closing part 100 that is closing the passage, which is not fixed to the passage, is pushed by the flow of electrolyte A. Receiving is separated from the inner wall of the passage to bend the valve-shaped opening and closing portion C as the electrolyte may pass through the opening and closing portion.

On the other hand, if the velocity of the electrolyte A gradually decreases, the pushing force of the electrolyte A decreases, so that the valve-shaped opening and closing portion separated from the inner wall of the passage decreases as shown in D. The amount of electrolyte gradually decreases. When the flow (A) of the electrolyte gradually decreases and the pushing force due to the flow (A) of the electrolyte cannot maintain the deflection of the opening or closing portion, or when the flow (A) of the electrolyte stops, it is fixed to the passage among the ends of the valve-shaped opening / closing part 100. The portion that is not in close contact with the inner wall of the passage prevents the electrolyte from passing through the opening and closing portion.

The valve-shaped opening and closing portion is preferably elastic so that it can be repeated to open and close the inlet installed in accordance with the flow of the electrolyte.

According to one embodiment of the present specification, the elastic force of the valve-shaped opening and closing portion may be 0.1 MPa or more and 10 MPa or less. Specifically, the elastic force of the valve-shaped opening and closing portion may be 0.5 MPa or more and 5 MPa or less.

According to one embodiment of the present specification, the opening and closing portion may be a watermill type.

The watermill type opening and closing support; And it may include a wing provided on the outer peripheral surface of the support. Specifically, as shown in Figure 4, the water wheel type opening and closing portion 200 is a support 210; And it may include a wing 220 provided on the outer peripheral surface of the support (210).

The watermill-type opening and closing part is provided in at least one of the cathode inlet, the cathode outlet, the anode inlet and the anode outlet, and when provided, both ends of the supports of the watermill-type opening and closing are fixed inside the passage. .

When the electrolyte solution does not flow, the surface of the wing of the watermill opening and closing portion is in close contact with the inside of the passage so that the electrolyte solution cannot pass through the watermill opening and closing portion.

When the electrolyte flows, the water is pushed by the electrolyte flowing through the wings of the water wheel type opening and closing portion of the water wheel type opening and closing the electrolyte while passing through the opening and closing portion.

Specifically, as shown in FIG. 4, when the flow A of the electrolyte occurs, the wing 220 of the watermill-type opening / closing part 200 closing the passage receives a force pushed by the flow A of the electrolyte. The electrolyte may pass through the opening and closing part while being separated from the inner wall of the support 210 while rotating as C about.

On the other hand, if the speed of the flow of the electrolyte (A) is gradually reduced, the force pushed by the flow (A) of the electrolyte is reduced, the rotational speed of the wing 220 is reduced, and as a result, the amount of the electrolyte passing through the opening and closing gradually decreases. When the flow (A) of the electrolyte gradually decreases and the pushing force by the flow (A) of the electrolyte cannot rotate the blade 220 or the flow (A) of the electrolyte stops, the blade of the watermill type opening / closing part 200 The surface of the 220 is in close contact with the inside of the passage so that the electrolyte cannot pass through the watermill-type opening and closing portion 200.

The watermill-type opening and closing portion is preferably elastic so that the wing of the watermill-type opening and closing portion is in contact with the inner wall of the passage in accordance with the flow of the electrolyte.

According to one embodiment of the present specification, the elastic force of the blade may be 0.1 MPa or more and 10 MPa or less. Specifically, the elastic force of the blade may be 0.5 MPa or more and 5 MPa or less.

Flow battery of the present specification is a negative electrode; anode; And an electrode cell including a separator disposed between the cathode and the anode.

The material of the negative electrode, the positive electrode and the separator is not particularly limited, and those generally used in the art may be employed.

The separator may include a porous support and an ion conductor provided in the pores of the porous support.

If the porous support includes a plurality of pores, the structure and material of the support are not particularly limited, and those commonly used in the art may be used.

For example, the porous support may be polyimide (PI), nylon, polyethylene terephtalate (PET), polytetrafluoro ethylene (PTFE), polyethylene (PE), polypropylene ( polypropylene: PP), polyarylene ether sulfone (PAES), and polyetheretherketone (PEEK).

The ion conductor is not particularly limited as long as it is a material capable of being filled in the pores of the porous support and ion exchange, it can be used generally used in the art.

For example, the ion conductor is Nafion, sulfonated polyetheretherketone (sPEEK) sulfonated polyetherketone (sPEK), sulfonated (polyetherketone), polyvinylidene fluoride-graft-polystyrene It may comprise at least one of sulfonic acid (poly (vinylidene fluoride) -graft-poly (styrene sulfonic acid), PVDF-g-PSSA) and sulfonated poly (fluorenyl ether ketone).

The flow battery of the present specification may further include a cathode electrolyte injected and discharged to the cathode side and a cathode electrolyte injected and discharged to the anode side.

The cathode electrolyte and the cathode electrolyte may each include an electrolyte and a solvent.

The electrolyte and the solvent are not particularly limited, but those commonly used in the art may be employed.

In one embodiment of the present specification, the flow battery may use V (IV) / V (V) redox couple as the cathode electrolyte and V (II) / V (III) redox couple as the cathode electrolyte. have.

In another exemplary embodiment of the present specification, the flow battery may use a halogen redox couple as a cathode electrolyte and a V (II) / V (III) redox couple as a cathode electrolyte.

In another exemplary embodiment of the present specification, the flow battery may use a halogen redox couple as the cathode electrolyte and a sulfide redox couple as the cathode electrolyte.

In another exemplary embodiment of the present specification, the flow battery may use a halogen redox couple as the cathode electrolyte, and zinc (Zn) redox couple as the cathode electrolyte.

The flow battery of the present specification may further include a pump connected to a cathode tank and an anode tank for storing a cathode electrolyte or an anode electrolyte, respectively, to supply the electrolyte to the cathode or the anode.

The flow battery may be a redox flow battery.

The type of the redox flow battery is not limited, but a vanadium-based redox flow battery, a lead-based redox flow battery, a polysulfide bromine (PSB) redox flow battery, and a zinc-bromine (Zn-Br) redox flow Battery or the like.

The shape of the flow battery is not limited, and may be, for example, coin, flat, cylindrical, horn, button, sheet or stacked.

The present specification provides a battery module including the flow battery as a unit cell.

The battery module may be formed by inserting and stacking a bipolar plate between flow batteries according to an exemplary embodiment of the present application.

Specifically, the battery module may be used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

1: housing
10: separator
21: cathode 22: anode
25: negative electrode current collector
31: cathode discharge furnace 32: anode discharge furnace
41: cathode inlet 42: anode inlet
45: passage of cathode inlet
100: valve opening and closing portion
200: watermill type opening and closing portion
210: support 220: wing
A: Flow of electrolyte in the cathode inlet
B: Flow of Electrolyte in Cathode

Claims (11)

Cathode and anode;
A cathode tank and an anode tank for storing a cathode electrolyte or a cathode electrolyte, respectively;
A cathode inflow path provided to allow the anode electrolyte to flow into the cathode from the anode tank;
A cathode discharge passage provided to discharge the cathode electrolyte from the cathode to the anode tank;
An anode inflow path provided to allow the anode electrolyte to flow into the cathode from the anode tank;
An anode discharge passage provided to discharge the anode electrolyte from the anode to the anode tank; And
An end portion connected to the cathode in the cathode inlet passage; An end portion connected to the cathode in the cathode discharge path; An end portion connected to the anode in the anode inflow path; And an opening and closing portion provided at at least one of ends connected to the anode in the anode discharge path.
The opening and closing portion is at least one of the valve type and the watermill type,
The opening and closing part is made of polyacrylate, polyethylene (PE, polyethylene), polypropylene (PP, polypropylene), polyethylene terephthalate (PET, polyethylene terephthalate), polyethylene ether phthalate (polyethylene ether phthalate), polyethylene phthalate (polyethylene) phthalate, polybuthylene phthalate, polyethylenenaphthalate (PEN; Polyethylene Naphthalate), polycarbonate (PC; polycarbonate), polystyrene (PS, polystyrene), polyether imide, polyether sulfone sulfone), polyetheretherketone (PEEK; Polyetheretherketone), polyimide (PI; polyimide), polyvinylidene fluoride (PVDF, polyvinylidene fluoride), polytetrafluoroethylene (PTFE, Polytetrafluoroethylene) and at least one of polyketone In the group consisting of a single polymer, two or more mixtures or two or more copolymers The selected flow battery comprises a material of one kind. delete delete The method of claim 1, wherein the opening and closing portion is the end of the inside of the negative electrode inlet connected to the negative electrode; An end portion connected to the cathode in the cathode discharge path; An end portion connected to the anode in the anode inflow path; And end portions connected to the anodes in the anode discharge paths, respectively. delete The flow battery of claim 1, wherein an elastic force of the valve-shaped opening / closing part is 0.1 MPa or more and 10 MPa or less. The method of claim 1, wherein the water wheel type opening and closing portion support; And a wing provided on an outer circumferential surface of the support. The flow battery of claim 7, wherein an elastic force of the blade is 0.1 MPa or more and 10 MPa or less. The flow battery of claim 1, wherein the opening and closing part is opened when the electrolyte flows and closed when the electrolyte does not flow. delete Cell module comprising the flow battery of any one of claims 1, 4 and 6 to 9 as a unit cell.

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