KR101785769B1 - Flow battery and battery module comprising the same - Google Patents

Abstract

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

Description

FLOW BATTERY AND BATTERY MODULE COMPRISING THE SAME

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

A secondary battery is a device that converts external electrical energy into a form of chemical energy, stores it, and generates electricity when it is needed. The term "rechargeable battery" also means that the battery can be recharged several times.

2. Description of the Related Art [0002] Recent developments in wireless communication technology have led to the popularization of portable devices, and there is a tendency to wirelessize many types of conventional devices, so that the demand for secondary batteries applicable to wireless devices is increasing.

Generally, a secondary battery is a cylindrical, square, or pouch type battery. This is because the secondary battery is manufactured by inserting an electrode assembly composed of a cathode, an anode, and a separator into a pouch-shaped case of a cylindrical or rectangular metal can or an aluminum laminate sheet, and injecting an electrolyte into the electrode assembly. Therefore, since a certain space for mounting the secondary battery is indispensably required, there is a problem that the cylindrical shape, the square shape, or the pouch shape of the secondary battery acts as a constraint on the development of various types of portable devices.

There is a need for a research on a cable type secondary battery, which is a battery having a very large length-to-diameter ratio with respect to the demand of a secondary battery in which the shape of the secondary battery is easily deformed.

Korean Patent Publication No. 2009-0046087

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

A first electrode comprising a first porous support of a rod shape and a first wire current collector passing through the first porous support in a longitudinal direction of the first porous support; A separator provided on the first electrode; And a second electrode including a second porous support provided on the separation membrane and a second wire current collector passing through the second porous support in a longitudinal direction of the second porous support, .

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

The flow battery according to one embodiment of the present invention has an advantage that the entire battery can be bent.

The flow battery according to one embodiment of the present specification can be used by being modified to suit the application form with a bendable rod type battery.

1 is a structure of a conventional flow battery.
2 is a perspective view of a flow battery of one embodiment in accordance with the present disclosure;
3 is a vertical cross-sectional view in the longitudinal direction of the flow battery in one embodiment according to the present specification.
4 is a longitudinal sectional view of a flow battery in one embodiment according to the present specification.
Figs. 5 and 6 are graphs of charge / discharge test results of Example 1. Fig.

Hereinafter, the present invention will be described in detail.

A first electrode comprising a first porous support of a rod shape and a first wire current collector passing through the first porous support in a longitudinal direction of the first porous support; A separator provided on the first electrode; And a second electrode including a second porous support provided on the separation membrane and a second wire current collector passing through the second porous support in a longitudinal direction of the second porous support, .

The flow battery of the present invention may include a first electrode and a second electrode.

The first electrode may be an anode or a cathode, and the second electrode may be an anode or a cathode, as opposed to the first electrode. That is, when the first electrode is an anode, the second electrode is a cathode, and when the first electrode is a cathode, the second electrode may be an anode.

In one embodiment of the present disclosure, the first electrode and the second electrode may be bent.

As long as the first electrode and the second electrode can be bent at room temperature or higher, the material thereof is not limited and those generally used in the art can be selected.

Wherein the first electrode comprises a first porous support in a rod form and a first wire current collector passing through the first porous support in a longitudinal direction of the first porous support, And a second wire current collector passing through the second porous support in the longitudinal direction of the second porous support.

In order for the first electrode and the second electrode to bend, the first porous support, the first wire current collector, the second porous support, and the second wire current collector constituting the first and second electrodes may be bent respectively.

The first porous support and the second porous support are not limited as far as they are conductive and are not corroded by acid, but the materials are not limited and those generally used in the art can be selected.

In one embodiment of the present disclosure, the first porous substrate and the second porous substrate may each comprise a porous carbon material.

In one embodiment of the present disclosure, the first porous support and the second porous support may each include at least one of carbon felt and graphite felt.

The diameter of the first porous support may be 1 mm or more and 50 mm or less. In the present specification, the diameter means the length of the longest straight line passing through the center of gravity in the cross section in the direction perpendicular to the longitudinal direction.

In the direction perpendicular to the longitudinal direction, the thickness of the second porous support may be 1 mm or more and 50 mm or less.

The shape of the first porous substrate of the bar is not particularly limited, but the cross-section of the first porous substrate in a direction perpendicular to the longitudinal direction may be a shape having a circle, an ellipse, a polygon, or a curved surface.

The elastic modulus of the first wire current collector and the second wire current collector may be 2400 N / mm ² or less, respectively. The elastic modulus of the first wire current collector and the second wire current collector is preferably 800 N / mm < ² > More than 2400 N / mm ² ≪ / RTI >

The first wire current collector and the second wire current collector may include a metal having high conductivity. For example, the first wire current collector and the second wire current collector may include at least one of stainless steel (SUS), copper, gold, and aluminum.

The first wire current collector and the second wire current collector may include a metal having an excellent conductivity and being resistant to an acid. The first wire current collector and the second wire current collector may be made of a metal having a high conductivity and a strong resistance to an acid or a metal having a high conductivity and a metal having an excellent conductivity and an acid resistance on the surface of the metal. For example, the first wire current collector and the second wire current collector may be a gold wire-plated copper wire.

The diameter of the first wire current collector and the diameter of the second wire current collector may be 1 μm or more and 10 mm or less, respectively.

The separator may be bent, and the material of the separator may be selected to be generally used in the art without any particular limitation as long as it can bend at room temperature or higher.

For example, the separation membrane may include a porous body and an ion conductor provided in the pores of the porous body.

If the porous body includes a plurality of pores, the structure and material of the body are not particularly limited, and those generally used in the art can be used.

For example, the porous body may be formed of a material selected from the group consisting of polyimide (PI), nylon, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyethylene (PE) polypropylene (PP), poly (arylene ether sulfone) (PAES), and polyetheretherketone (PEEK).

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

The ion-conducting polymer may be a hydrocarbon-based polymer, a partially fluorinated polymer, or a fluorinated polymer.

The hydrocarbon-based polymer may be a hydrocarbon-based sulfonated polymer having no fluorine group. Alternatively, the fluorinated polymer may be a sulfonated polymer saturated with a fluorine group, and the partially fluorinated polymer may be a sulfonated polymer that is not saturated with a fluorine group have.

The polymer having ionic conductivity may be at least one selected from the group consisting of perfluorosulfonic acid polymer, hydrocarbon polymer, aromatic sulfon polymer, aromatic ketone polymer, polybenzimidazole polymer, polystyrene polymer, polyester polymer, polyimide polymer, polyvinyl Based polymers, polyether sulfone-based polymers, polyphenylene sulfide-based polymers, polyphenylene oxide-based polymers, polyphosphazene-based polymers, polyethylene naphthalate-based polymers, polyester-based polymers, doped polybenzimidazole-based polymers And may be one or two or more polymers selected from the group consisting of polymers, polyether ketone polymers, polyphenylquinoxaline polymers, polysulfone polymers, polypyrrole polymers and polyaniline polymers. The polymer may be a single copolymer, an alternating copolymer, a random copolymer, a block copolymer, a multi-block copolymer or a graft copolymer, but is not limited thereto.

The ionic conductor may be a polymer having cationic conductivity, for example, Nafion, sulfonated polyetheretherketone (sPEEK), sulfonated (polyetherketone) sulphated polyetheretherketone (sPEEK), poly Polyvinylidene fluoride-graft-poly (styrene sulfonic acid), PVDF-g-PSSA) and sulfonated poly (fluorenyl ether ketone) Or the like.

The ion conductor may be an ion conductive polymer capable of transferring anions, and is not particularly limited as long as it can transfer anions, and conventional ones known in the art can be used. For example, the ion conductive polymer capable of transferring the anion may include styrene, vinylbenzyl chloride (VBC), divinylbenzene (DVB), trimethylamine (TMA), and amine functional groups And an anion exchange polymer having an anion exchange group.

In the direction perpendicular to the longitudinal direction, the thickness of the separation membrane may be 10 탆 or more and 500 탆 or less, and if necessary, the separation membrane may have a thickness of 50 탆 or more and 200 탆 or less.

A first electrolyte passing through the first electrode and including a first electrode active material; And a second electrolyte that passes through the second electrode and includes a second electrode active material.

In one embodiment of the present invention, the flow battery includes a first tank and a second tank for respectively storing the first electrolyte and the second electrolyte; And a housing in which the first electrode, the separator, and the second electrode are inserted,

The housing includes a first inlet and a second inlet through which the first electrolyte and the second electrolyte flow into the first electrode or the second electrode from the first tank and the second tank, respectively; And

The first electrolyte and the second electrolyte may have a first outlet and a second outlet, respectively, which are discharged from the first electrode and the second electrode to the first tank or the second tank.

The first electrolyte and the second electrolyte may flow into the first electrode or the second electrode, respectively, and may be discharged from the first electrode or the second electrode. The first electrolyte may be an anodic electrolytic solution or a cathode electrolytic solution And the second electrolyte may be a positive electrode electrolyte or a negative electrode electrolyte along with the second electrode. That is, when the first electrode is an anode and the second electrode is a cathode, the first electrolyte is a cathode electrolyte and the second electrolyte is a cathode electrolyte. When the first electrode is a cathode and the second electrode is an anode, the first electrolyte is a cathode electrolyte The second electrolyte may be a positive electrode electrolyte.

The first electrolyte and the second electrolyte may include an electrode active material and a solvent, respectively. At this time, the electrode active material and the solvent are not particularly limited, and those generally used in the art can be selected.

In one embodiment of the present invention, the redox flow battery uses a V (IV) / V (V) redox couple as a cathode active material and a V (II) / V Can be used.

In another embodiment of the present invention, the redox flow battery may use a halogen redox couple as a cathode active material and a V (II) / V (III) redox couple as an anode active material.

In another embodiment of the present invention, the redox flow battery uses a halogen redox couple as a cathode active material and a sulfurized redox couples as an anode active material.

In another embodiment of the present invention, the redox flow battery may use a halogen redox couple as a positive electrode active material and a zinc redox couple as a negative electrode active material.

The solvent is not particularly limited as long as it can dissolve the active material. For example, when the cathode active material is a V (IV) / V (V) redox couple and the anode active material is a V (II) / V In the case of a flow battery, the solvent capable of dissolving the active material may include sulfuric acid, hydrochloric acid, nitric acid, and a mixed solution thereof.

The flow battery in this specification may be a flow battery that can bend at room temperature or higher. The flow battery in this specification may be a cable-type flow battery that can bend at room temperature or higher.

In one embodiment of the present invention, the length of the flow battery is not particularly limited, and the diameter of the flow battery may be 1 mm or more and 10 cm or less if necessary.

The ratio of the diameter of the flow battery to the length of the flow battery may be from 1: 0.01 to 1: 1.

Here, the diameter and length of the flow battery refer to the diameter and length of the entire battery including the first electrode, the separator, and the second electrode.

The shape of the flow battery is not particularly limited as long as it is in the form of a bar, but the cross-section of the flow battery may be circular, elliptical, polygonal or curved in a direction perpendicular to the longitudinal direction.

A first electrode comprising a current collector and an active material layer coated on the current collector surface; A separator provided on the first electrode; And a second electrode provided on the separation membrane and including a current collector and an active material layer coated on the surface of the current collector, the active material detaches from the surface of the current collector as the number of times of bending increases, The efficiency of the battery gradually decreases.

However, the present specification is a flow battery having a cable-type structure, and the electrode active material is circulated together with the electrolytic solution, so that the stability of the electrode active material is increased with an increase in the number of times of bending. The flow battery of the present invention can overcome the problem that the efficiency of the battery decreases as the number of times of bending increases.

Wherein the electrode comprises a porous support; And an electrode active material flowing together with the electrolytic solution, which is advantageous in flexibility or bending property.

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

The flow battery in this specification may be a redox flow battery.

The flow battery in this specification can be applied to a small electronic device, a product requiring flexibility. For example, a top; pants; underwear; Other wearable accessories such as watches, necklaces, hair bands, shoes, belts, rings, bags, hats, glasses, earrings, bracelets and braces; Or small electric peripherals such as cellular phones, earphones, headsets, notebooks, and tablets.

The flow battery of the present invention can 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.

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

The battery module may be a unit battery of the flow battery of the present invention, and two or more flow batteries may be connected in series.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following embodiments are intended to illustrate the present disclosure and are not intended to limit the present disclosure.

[Example]

[Example 1]

The separator was fabricated by Sumitomo TB0403 hollow fiber, the ion conductor was impregnated with Nafion 115 resin, the electrode was fabricated by using carbon felt and SUS wire, and the electrolyte solution was prepared by dissolving VOSO ₄ as an active material in an aqueous sulfuric acid solution, Thereby manufacturing a flow battery. At this time, the length of the flow battery was 8 cm and the total diameter was 1.5 cm.

[Experimental Example 1]

Charge-discharge experiment

Charge current was charged to 1.8V at 5mA and discharge was discharged to 0.5V at 2mA. The results are shown in Fig. 5 and Fig.

5 is a voltage-capacity result graph obtained by charging / discharging the flow battery manufactured in Example 1 from 1.8V to 0.5V 10 times. This indicates that the battery manufactured in Example 1 is charged and discharged.

The graph of FIG. 6 shows the charge capacity and the discharge capacity expressed in the total of 10 charge / discharge cycles in FIG. It can be seen that the charge capacity of the flow battery manufactured in the first embodiment is 25 mAh on average.

100: Positive electrode current collector 110: Positive electrode carbon felt
120: anode electrolyte
200: negative electrode current collector 210: negative electrode carbon felt
220: cathode electrolyte
300: positive electrode electrolyte tank 330: positive electrode electrolyte pump
350: positive electrode electrolyte inlet 370: anode electrolyte outlet
400: cathode electrolytic solution tank 430: cathode electrolytic solution pump
450: cathode electrolyte inlet 470: cathode electrolyte outlet
500: first porous support 530: first wire collector
550: first electrode
600: membrane
700: second porous support 730: second wire collector
750: second electrode
800: Housing

Claims (15)

A first electrode comprising a first porous support of a rod shape and a first wire current collector passing through the first porous support in the longitudinal direction of the first porous support;
A separator provided on the first electrode; And
And a second electrode including a second porous support provided on the separation membrane and a second wire current collector passing through the second porous support in the longitudinal direction of the second porous support. The plasma display panel of claim 1, further comprising: a first electrolyte that passes through the first electrode and includes a first electrode active material; And a second electrolyte that passes through the second electrode and includes a second electrode active material. [3] The apparatus of claim 2, further comprising: a first tank and a second tank for respectively storing the first electrolyte and the second electrolyte;
A first inlet and a second inlet through which the first electrolyte and the second electrolyte flow into the first electrode or the second electrode from the first tank and the second tank, respectively; And
Further comprising a first outlet and a second outlet through which the first electrolyte and the second electrolyte are discharged from the first electrode and the second electrode to the first tank or the second tank, respectively. The flow battery according to claim 1, wherein the diameters of the first wire current collector and the second wire current collector are respectively 1 m to 10 mm. The flow battery according to claim 1, wherein the diameter of the first porous support is 1 mm or more and 50 mm or less. The flow battery according to claim 1, wherein the thickness of the separation membrane is 10 μm or more and 500 μm or less in a direction perpendicular to the longitudinal direction. The flow battery according to claim 1, wherein the thickness of the second porous support is not less than 1 mm and not more than 50 mm in a direction perpendicular to the longitudinal direction. The flow battery according to claim 1, wherein the flow battery has a diameter of 1 mm or more and 10 cm or less. The flow battery of claim 1, wherein the ratio of the diameter of the flow battery to the length of the flow battery is 1: 0.01 to 1: 1. The flow battery according to claim 1, wherein the flow battery is a flow battery that can be bent. The flow battery according to claim 1, wherein the elastic modulus of the first wire current collector and the second wire current collector is 2400 N / mm ² or less. The flow battery according to claim 1, wherein the first wire current collector and the second wire current collector each include at least one of stainless steel (SUS), copper, gold, and aluminum. The flow battery of claim 1, wherein the first porous substrate and the second porous substrate comprise a porous carbon material. The flow battery of claim 1, wherein the first porous substrate and the second porous substrate each comprise at least one of a carbon felt and a graphite felt. A battery module comprising the flow battery of any one of claims 1 to 14 as a unit cell.

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