KR20160107644A - Electrolyte injection apparatus and electrolyte injection method - Google Patents

Abstract

Provided are an apparatus for injecting an electrolyte capable of increasing productivity of a rechargeable battery by omitting an electrolyte impregnation process and a method of injecting an electrolyte. The apparatus for injecting an electrolyte according to the present invention comprises: a vacuum chamber accommodating a battery cell; a vacuum pump connected with the vacuum chamber and forming a vacuum pressure in the vacuum chamber; a jig fixing the battery cell in the vacuum chamber; an electrolyte container positioned at an upper portion of the vacuum chamber and containing an electrolyte; an air tube communicating with the electrolyte container and the vacuum chamber and maintaining the same system; an electrolyte supply unit injecting the electrolyte into the battery cell; and a thermosetting unit sealing an inlet part of the battery cell through thermosetting after the electrolyte is injected.

Description

[0001] ELECTROLYTE INJECTION APPARATUS AND ELECTROLYTE INJECTION METHOD [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolyte injecting apparatus and an injecting method, and more particularly, to an electrolyte injecting apparatus and an injecting method which can omit an electrolyte solution impregnating step.

2. Description of the Related Art In recent years, demand for portable electronic products such as notebook computers, video cameras, and portable telephones has been rapidly increased, and electric vehicles, storage batteries for energy storage, robots, and satellites have been developed in earnest. Are being studied actively.

The secondary rechargeable batteries are nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel- It is very popular because of its low self-discharge rate and high energy density.

On the other hand, as the capacity of the secondary battery increases and the unit size of the electrode plate of the secondary battery increases, the impregnation of the electrolyte becomes more important. The manufacturing process of the secondary battery generally includes a process in which a liquid electrolyte, that is, an electrolyte is injected while the electrode assembly is housed in the battery case, and the battery case is sealed.

Here, the electrolyte injected into the battery case is imbibed by the capillary force between the positive electrode plate, the negative electrode plate and the separator constituting the electrode assembly. However, the positive electrode plate, the negative electrode plate and the separator are materials having high hydrophobicity, whereas the electrolyte is a material having high hydrophilicity. It takes a considerable time to impregnate the electrode assembly with the electrolyte, and the process conditions are also severe.

If the impregnation (wetting) of the electrolytic solution becomes incomplete, not only the charging / discharging characteristics of the secondary battery such as the capacity of the secondary battery are lowered, but also the non-uniformity of the electrode state can be intensified. As a result, there is a concern that the electrode reaction locally concentrates and causes serious problems in the safety of the battery. In addition, when the size of the electrode plate is increased, the time required for impregnation of the electrolyte increases, thereby deteriorating the productivity of the secondary battery. In addition, although the impregnation failure of the electrolyte solution is good in other electrode states, there is a problem that the life of the battery can be shortened by accelerating degradation of the electrode.

In addition, the electrolytic solution impregnation step is generally performed by a method of repeating the state of the impregnation chamber in a vacuum state and a non-vacuum state after the battery cell is housed in the impregnation chamber, Since the non-vacuum state must be repeated, it is necessary to provide an impregnation chamber having a function of pressurizing and depressurizing, which is complicated and requires extensive facilities. In addition, there is a problem that the electrolytic solution overflows during the impregnation process.

An object of the present invention is to provide an electrolyte injecting apparatus and an injecting method which can reach a sufficient impregnation state even if the electrolytic solution impregnation step is omitted.

According to an aspect of the present invention,

A battery cell is received and a vacuum chamber,

A vacuum pump connected to the vacuum chamber and forming a vacuum pressure in the vacuum chamber,

A jig for fixing the battery cell in the vacuum chamber,

An electrolyte container positioned above the vacuum chamber and containing an electrolyte,

An air tube communicating with the electrolyte container and the vacuum chamber,

An electrolyte supply part for injecting the electrolyte into the battery cell, and

And a thermally fused portion for sealing the inlet portion of the battery cell through thermal fusion after the completion of the injection of the electrolyte solution.

Preferably, the vacuum chamber may include a door on one side of which the battery cell can be loaded or unloaded.

Preferably, the vacuum pump is capable of forming a vacuum degree of 20 to 30 Torr.

Preferably, the electrolyte solution supply unit may include a check valve capable of adjusting an amount of the electrolyte solution injected.

Preferably, the apparatus further includes an electrolyte auxiliary tank located above the vacuum chamber and communicating with the electrolyte container.

The apparatus may further include a metering pump which is in communication with the electrolyte container and the electrolyte auxiliary tank and supplies a predetermined amount of the electrolyte solution from the electrolyte auxiliary tank to the electrolyte container.

Preferably, the diameter of the electrolyte supply part may be 3 to 5 mm.

Further, in the electrolyte injection method according to the present invention,

(a) charging a battery cell into a vacuum chamber and fixing it with a jig;

(b) filling the electrolyte vessel with an electrolytic solution;

(c) maintaining the degree of vacuum of the vacuum chamber and the electrolyte container at 20 to 30 Torr using a vacuum pump;

(d) injecting an electrolyte into the battery cell through the electrolyte supply unit in the vacuum degree; And

(e) sealing and discharging the battery cell.

Preferably, in the step (b), the electrolyte solution may be filled from the electrolyte auxiliary tank into the electrolyte solution container via a metering pump.

Preferably, in the step (d), the electrolytic solution may be injected in an amount of 700 to 900 g for 60 to 80 seconds.

Preferably, in the step (c), the degree of vacuum of the vacuum chamber and the electrolyte container may be kept the same through an air tube communicating with the vacuum chamber and the electrolyte container.

Preferably, the battery cell may be a pouch-shaped cell.

According to the present invention, productivity of the secondary battery can be improved by omitting the step of impregnating the electrolyte solution.

Further, according to the present invention, since a large-scale and complicated facility is not required, it is possible to reduce the cost of space and facilities.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention. And should not be construed as limiting.
1 and 2 are front views schematically showing an electrolyte injection device according to an embodiment of the present invention.
3 is a flowchart illustrating an electrolyte injection method according to an embodiment of the present invention.
4 to 6 are photographs showing the impregnation degree of the battery cell manufactured according to Examples, Comparative Examples 1 and 2, respectively.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be construed as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The embodiments of the present invention are provided to explain the present invention more fully to the ordinary artisan, so that the shape and size of the components in the drawings may be exaggerated, omitted or schematically shown for clarity. Thus, the size or ratio of each component does not entirely reflect the actual size or ratio.

1 is a front view schematically showing an electrolyte injection device according to an embodiment of the present invention. The apparatus for injecting an electrolyte according to the present invention comprises a vacuum chamber 10 for accommodating a battery cell 20, a vacuum pump 30 connected to the vacuum chamber for forming a vacuum pressure in the vacuum chamber, An electrolytic solution supply unit 50 for injecting an electrolytic solution into the battery cell and an electrolytic solution supply unit 50 connected to the electrolytic solution container and the vacuum chamber, And an air tube 40 that keeps the same.

2 is a front view schematically showing an electrolyte injection device according to an embodiment of the present invention. The apparatus for injecting an electrolyte according to the present invention comprises a vacuum chamber (10) for accommodating a battery cell (20), a vacuum pump (30) connected to the vacuum chamber and forming a vacuum pressure in the vacuum chamber; A jig (11) for fixing the battery cell; An electrolyte container 60 located above the vacuum chamber and containing an electrolyte solution; An electrolyte auxiliary tank (61) located above the vacuum chamber and communicating with the electrolyte container (60); A metering pump 70 communicating with the electrolyte container 60 and the electrolyte auxiliary tank 61 and supplying a predetermined amount of electrolyte from the electrolyte auxiliary tank 61 to the electrolyte container 60; An electrolyte supply part 50 for injecting an electrolyte into the battery cell; And an air tube (40) for keeping the system in communication with the electrolyte container and the vacuum chamber.

In addition, the electrolyte injector according to the present invention may further include a thermally fused portion 12 for sealing the inlet portion of the battery cell 20 through thermal fusion after the completion of the injection of the electrolyte solution.

The vacuum chamber 10 may include a door. The battery cell can be carried in or out through the door, and the closed door maintains the vacuum chamber 10 in a sealed state.

The battery cell 20 is a unit cell capable of performing charging and discharging. The battery cell may include an electrode assembly, an electrolyte, and a battery case.

The electrode assembly may comprise a unit cell having a positive electrode plate having a positive electrode tab, a negative electrode plate having a negative electrode tab, and a separator, or may be an aggregate of the unit cells. That is, the electrode assembly may include at least one of a positive electrode plate, a separator, and a negative electrode plate. In addition, such an electrode assembly can be formed by a method in which unit cells are sequentially laminated, laminated, and then wound or folded. The material of the positive electrode plate, the separator, and the negative electrode plate of the electrode assembly is not particularly limited, and may be used without limitation in the present invention as long as it is commonly used in this technical field.

For example, although not limited thereto, the negative electrode plate may be formed of a lithium metal, lithium alloy, carbon, petroleum coke, activated carbon, graphite, and the like on both surfaces of a negative electrode current collector produced by copper, nickel, copper alloy, The anode active material coated with the same negative electrode active material may be used. The positive electrode plate may be formed by coating a positive electrode active material such as lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, or the like on both surfaces of a positive electrode current collector made of aluminum, nickel or a combination thereof.

The separator is disposed between the positive electrode plate and the negative electrode plate so as to insulate the positive electrode plate from the negative electrode plate so that active material ions can be exchanged between the positive electrode plate and the negative electrode plate. Another separator may be disposed on the outside of the positive electrode plate or the negative electrode plate so that an insulating state is established between the positive electrode plate and the negative electrode plate when the electrode assembly is wound.

The electrolytic solution is a substance which dissolves in a solvent and dissociates into ions to pass electricity in a solution or a molten state, and carries charges when a voltage is applied. When such an electrolyte solution is sufficiently and uniformly impregnated in the electrode assembly, the secondary battery can exert its original function properly. If the electrolyte solution is imperfectly impregnated in the electrode assembly, not only the charge / discharge characteristics of the secondary battery are degraded, but also degradation of the electrode is accelerated and the service life of the battery can be shortened.

The battery case may provide a space in which the electrode assembly is housed and into which the electrolyte solution is injected. Such a battery case may be classified into a rectangular type battery case and a pouch type battery case depending on the type. Further, the pouch-shaped battery case may be constituted of an upper pouch and a lower pouch for facilitating storage of the electrode assembly.

The electrolyte container 60 accommodates the electrolyte and is located at the top of the vacuum chamber. The electrolyte container 60 may contain a predetermined amount of electrolyte to be supplied to the battery cells.

The electrolyte auxiliary tank 61 communicates with the electrolyte container 60 and can receive an extra electrolyte to be supplied to the electrolyte container 60.

The metering pump 70 can supply a predetermined amount of electrolyte to be supplied to the battery cell from the electrolyte auxiliary tank 61 to the electrolyte container 60. Therefore, in the electrolyte injecting step, the electrolytic solution is stored in the electrolytic solution container 60 in a predetermined amount beforehand, so that the process can be performed quickly.

The electrolyte supply part 50 is in the form of a nozzle which communicates with the lower part of the electrolyte container 60 and extends through the upper part of the vacuum chamber 10. The upper end of the electrolyte solution supply unit 50 may further include a check valve capable of controlling the flow rate of the electrolyte solution. Also, the diameter of the electrolyte solution supply part 50 may be 3 to 5 mm.

The air tube 40 is for maintaining the vacuum chamber 10 and the electrolyte container 60 in the same system and communicates the vacuum chamber 10 and the electrolyte container 60. That is, the atmospheric pressures of the vacuum chamber 10 and the electrolyte container 60 can be maintained in the same state.

The vacuum pump 30 is located at one side of the vacuum chamber 10 and can communicate with the pump pipe 31. The degree of vacuum of the vacuum chamber 10 can be controlled and the degree of vacuum of the electrolyte container 60 communicated by the air tube 40 can be controlled in the same manner.

The jig 11 fixes the battery cell inside the vacuum chamber. The jig 11 can be moved in the thickness direction of the battery cell and can be any shape capable of fixing the battery cell.

FIG. 3 is a flowchart illustrating a method of injecting an electrolyte according to an embodiment of the present invention.

Referring to FIG. 3, in order to inject the electrolyte into the electrode assembly according to the present invention, first, (a) the battery cell 20 is injected into the vacuum chamber 10 and fixed with the jig 11.

At this time, the electrode assembly is housed in the battery cell 20 and then charged into the vacuum chamber 10. When the electrolyte is injected into the jig 11, the shape of the battery cell 20 can be secured.

(B) Filling the electrolyte container 60 with the electrolyte solution. The electrolytic solution can be directly filled into the electrolyte container 60 and a separate electrolyte auxiliary tank 61 is provided so that only a certain amount of electrolyte injected into the battery cell through the metering pump 70 is filled in the electrolyte container 60 . By providing the electrolyte auxiliary tank 61, it is possible to supply the prepared electrolyte immediately for each step of injecting the electrolyte solution into the battery cell, thereby shortening the process time.

Thereafter, (c) the degree of vacuum of the vacuum chamber 10 is maintained at 20 to 30 Torr by using the vacuum pump 30. As the air tube 40 maintains the vacuum chamber 10 and the electrolyte vessel 60 in the same system, the degree of vacuum of the electrolyte vessel 60 is also maintained at 20 to 30 Torr.

Next, (d) an electrolyte is injected into the battery cell 20 through the electrolyte supply part 50 at a degree of vacuum of 20 to 30 Torr. Since the injection of the electrolyte solution is performed in a single system, the shrinkage of the battery cell due to the difference in the system before and after the injection of the electrolyte solution can be prevented. Further, as the electrolyte is injected in a vacuum state, the battery cell can reach a sufficient impregnation state. The electrolytic solution may be injected in an amount of 700 to 900 g, and the injection time may be 60 to 80 seconds. The diameter of the electrolyte supply part 50 may be 3 to 5 mm.

Finally, (e) the battery cell 20 in which the electrolyte injection is completed is sealed and discharged by the heat-sealed portion 12.

Hereinafter, the present invention will be described in more detail with reference to experimental examples. However, the following experimental examples are merely examples of the present invention, and the scope of the present invention is not limited thereto.

Example

A battery cell having a thickness of 16 mm, a width of 460 mm and a length of 330 mm was prepared, and 860 g of the electrolyte was injected for 70 seconds under a vacuum of 25 to 30 Torr.

Comparative Example 1

A battery cell having a thickness of 16 mm, a width of 460 mm and a length of 330 mm was prepared and the impregnation process was performed for 10 minutes with 860 g of the electrolyte.

Comparative Example 2

A battery cell having a thickness of 16 mm, a width of 460 mm and a length of 330 mm was prepared, 860 g of an electrolyte was injected, and no impregnation process was performed.

Experimental Example

The degree of electrolyte aggregation, cell flatness, cell hardness and impregnation degree of the battery cells prepared according to Examples and Comparative Examples 1 and 2 were measured. The measured results are shown in Table 1 below.

division Electrolyte aggregation Flatness of cell The hardness of the cell Example none Good Good Comparative Example 1 none Good Good Comparative Example 2 Clustering occurs Unevenness Bad

In Table 1, it was determined whether electrolyte accumulation occurred in the battery cell. The flatness of the cell measured the uniformity of the thickness of the battery cell, and the hardness of the cell was the shape of the battery cell The degree of retention was measured. In the case of the battery cell manufactured according to the embodiment, no electrolyte aggregation occurred, and the flatness and hardness of the cell were good. In Comparative Example 1 in which the impregnation process was performed, good results were obtained in the same manner as in Examples. However, in Comparative Example 2 in which the impregnation process was not performed, electrolyte aggregation occurred, the thickness of the cell was not uniform, The results were not well maintained.

4 to 6 are photographs showing the impregnation degree of the battery cell manufactured according to Examples, Comparative Examples 1 and 2, respectively. Referring to FIGS. 4 to 6, it can be seen that the battery cell manufactured according to the embodiment has better impregnation than the battery cell manufactured according to Comparative Examples 1 and 2.

Therefore, it can be seen that the battery cell manufactured by the electrolyte injection method according to the present invention has the same or improved results as compared with the battery cell in which the impregnation process is performed, and the process can be simplified and productivity can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

In the foregoing description or drawings, the use of terms such as upper, lower, inner, and outer is used to distinguish one element from another, and is merely an instrumental concept for improving the efficiency of explanation , Physical location, posterior relations, etc., should not be construed as being used to distinguish by absolute criteria.

10: Vacuum chamber
11: Jig 12: Heat-sealed portion
20: Battery cell
30: Vacuum pump 31: Pump piping
40: air tube
50: electrolyte injection part 51: check valve
60: electrolyte container 61: electrolyte auxiliary tank
70: metering pump

Claims (14)

A vacuum chamber for receiving the battery cell;
A vacuum pump connected to the vacuum chamber and forming a vacuum pressure in the vacuum chamber;
A jig fixing the battery cell in the vacuum chamber;
An electrolyte container positioned above the vacuum chamber and containing an electrolyte solution;
An air tube communicating with the electrolyte container and the vacuum chamber and keeping the system in the same state;
An electrolyte supply part for injecting the electrolyte into the battery cell; And
And a thermally fused portion for sealing the inlet portion of the battery cell through thermal fusion after the injection of the electrolyte is completed. The method according to claim 1,
Wherein the vacuum chamber has a door that can carry or carry the battery cell on one side thereof. The method according to claim 1,
Wherein the vacuum pump forms a vacuum degree of 20 to 30 Torr. The method according to claim 1,
Wherein the electrolyte solution supply unit is provided with a check valve capable of controlling the amount of the electrolyte solution injected. The method according to claim 1,
And an electrolyte auxiliary tank disposed at an upper portion of the vacuum chamber and communicating with the electrolyte container. 6. The method of claim 5,
Further comprising a metering pump that is in communication with the electrolyte container and the electrolyte auxiliary tank and supplies a predetermined amount of the electrolyte solution from the electrolyte auxiliary tank to the electrolyte solution container. The method according to claim 1,
And the diameter of the electrolyte supply part is 3 to 5 mm. The method according to claim 1,
Wherein the battery cell is a pouch type cell. (a) charging a battery cell into a vacuum chamber and fixing it with a jig;
(b) filling the electrolyte vessel with an electrolytic solution;
(c) maintaining the degree of vacuum of the vacuum chamber and the electrolyte container at 20 to 30 Torr using a vacuum pump;
(d) injecting an electrolyte into the battery cell through the electrolyte supply unit in the vacuum degree; And
(e) sealing and discharging the battery cell. 10. The method of claim 9,
Wherein in the step (b), the electrolytic solution is filled from the electrolyte auxiliary tank through the metering pump into the electrolyte solution container. 10. The method of claim 9,
Wherein the diameter of the electrolyte supply part is 3 to 5 mm. 10. The method of claim 9,
Wherein in the step (d), the electrolyte is injected in an amount of 700 to 900 g for 60 to 80 seconds. 10. The method of claim 9,
Wherein in the step (c), the degree of vacuum of the vacuum chamber and the electrolyte container are kept the same through an air tube communicating with the vacuum chamber and the electrolyte container. 10. The method of claim 9,
Wherein the battery cell is a pouch type cell.

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