KR20170135293A - Electrolyte Wetting System for Secondary Battery and Method Using the Same - Google Patents

Abstract

The present invention relates to an electrolyte impregnating method which includes an electrolyte injecting device for injecting an electrolyte into the inside of a battery cell, a pressing device for pressing both surfaces of the battery cell in order to improve the impregnating property of the electrolyte in a state in which the electrolyte is injected, one or more chambers including rotating devices to rotate the battery cell, a decompressing device for bringing the inside of the chamber into a vacuum state, and a die on which the one or more chambers are mounted. Accordingly, the present invention can improve the impregnating property of the electrolyte by uniformly spreading the electrolyte on an electrode and a separator.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrolyte impregnation system for a secondary battery and an electrolyte impregnation method using the same.

The present invention relates to an electrolyte impregnation system for a secondary battery and an electrolyte impregnation method using the same.

As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among such secondary batteries, many studies have been made on lithium secondary batteries having high energy density and discharge voltage, Widely used.

In general, the lithium secondary battery is assembled by inserting the positive electrode, the negative electrode and the separator into each other, alternately inserting the positive electrode, the negative electrode and the separator in a battery case made of a can or pouch having a predetermined size and shape, It proceeds. At this time, the electrolyte injected later is impregnated between the anode, the cathode and the separator by a capillary force. However, due to the nature of the materials, the anodes, the cathodes, and the separator are both hydrophobic substances, while the electrolyte is a hydrophilic material, so that wetting of the electrodes and the separator of the electrolyte may take a considerable amount of time, .

In recent years, as the size of a device or a device becomes larger, a demand for a large-capacity battery is continuously increasing, and a problem is raised to increase the impregnation rate of the electrolyte. That is, in addition to the fundamental hydrophilicity difference, as the area and thickness of the electrode to which the electrolytic solution should permeate increases, the possibility that the electrolytic solution does not reach the inside of the battery but exists only locally exists. The battery thus produced partially lacks the amount of the electrolyte inside the battery, thereby greatly reducing the capacity and performance of the battery

In order to improve the impregnability of such an electrode with an electrolyte, a method of injecting an electrolyte at a high temperature or injecting an electrolyte at a pressure or a reduced pressure has been used. However, the existing separator shrinks due to heat, causing an internal short circuit, or the electrolytic solution can not be uniformly penetrated to all the parts.

Accordingly, there is a great need for a secondary battery technology that not only increases the impregnation rate of the electrolyte, but also uniformly impregnates the electrolyte in all parts of the battery, thereby exhibiting high capacity and high efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments. As described later, when the electrolyte impregnation system including the pressurizing device and the rotating device is used, the impregnation property of the electrolyte is improved and the storage period after the electrolyte impregnation Is shortened, and as a result, the overall production period is shortened, and the present invention has been completed.

According to an aspect of the present invention, there is provided an electrolyte solution impregnation system comprising:

An electrolyte injection device for injecting an electrolyte into the battery cell;

One or more chambers in which a pressing device for pressing both sides of the battery cell and a rotating device for rotating the battery cell are provided inside the battery cell in order to enhance the impregnation property of the electrolyte solution in the state where the electrolyte solution is injected;

A decompression device for evacuating the interior of the chamber; And

A die having one or more chambers mounted thereon

As shown in FIG.

As described above, the electrolyte injection device according to the present invention includes a plurality of chambers provided with a pressurizing device and a rotating device, and improves the permeability of the electrolyte through the pressurization of the battery cell into which the electrolyte is injected, It is possible to uniformly spread the electrolytic solution over the electrodes and the separator through the rotational motion, and as a result, it is possible to provide a battery cell in which the electrolyte impregnability is remarkably improved.

In addition, since a plurality of chambers are included, electrolyte impregnation can be performed on many battery cells at the same time. Therefore, the efficiency of the production process of the battery cell can be improved as compared with the prior art in which only the method of pressing both sides of the battery cell is used, or the rotation is performed with respect to one battery cell for each rotation device.

In one specific example, the chambers are arranged in a detachable structure along the outer periphery of the die, except for the central portion of the die, which is circular in plan view, such that the process of accommodating the battery cells in the chamber and / The die is of a rotatable construction.

The number of chambers that can be mounted on the die may be from 3 to 12, more specifically from 4 to 8.

In the chamber, a pair of pressurizing devices and a rotating device are provided. In the state where one or two or more battery cells are positioned between the pair of pressurizing devices, the pressurizing device moves toward the battery cells The permeability of the electrolyte solution to the electrode and the separation membrane can be improved.

In addition, since the battery cells are housed in each of the plurality of chambers and can be integrally pressed and rotated, the efficiency of the manufacturing process can be improved.

Meanwhile, since the chambers having uniform sizes can be mounted on the die, the chambers are suitable for manufacturing battery cells of the same size or a plurality of chambers having various sizes can be mounted. Sized battery cells.

In one specific example, the die is of a plate-like structure rotatable in parallel with the ground, and the chamber is divided into n battery cells from the first chamber to the nth chamber (n is a natural number of 3? N? 10) And the die may be configured to rotate in one direction in the course of sequentially storing the battery cells in the chamber.

Specifically, the first chamber in which the first battery cell is housed is moved to the nth chamber position, the die is rotated so that the second chamber is located in the first chamber seat, and the second chamber in which the second battery cell is housed is rotated The first chamber is moved to the first chamber and the third chamber is positioned in the second chamber. The first to n < th > battery cells may be accommodated in the respective chambers.

On the other hand, when the height of the electrolyte injected into the battery cell is too high, the electrolyte can flow out when the battery cell is pressurized. If the height of the battery cell is too low, complete impregnation is difficult. And may be configured to press both sides of the battery cell when the height of the electrolyte reaches a certain level or more. Specifically, the height of the electrolytic solution above the predetermined level is preferably 0.5 mm to 20 mm smaller than the height of the built-in electrode assembly.

In one specific example, the battery cell can be rotated while being positioned so that the protruding direction of the electrode terminal is upward, and the rotating device has a rotation axis parallel to the protruding direction of the electrode terminal of the battery cell, And the rotation axis may be a virtual rotation axis.

In addition, the rotating device is provided in each of the chambers. In this case, even when a plurality of battery cells are accommodated in the chamber, The battery cells may be rotated based on the passing rotation axis.

The size of the battery cells housed in the chambers may be the same or different from each other. Considering the size and thickness of the battery cells, the rotation speed and / As shown in FIG.

In this case, since the rotating device can provide the battery cells with repetitive rotational force in the clockwise direction and the counterclockwise direction, in order to uniformly impregnate the inside of the battery cell as a whole, And it is more preferable that the rotational speed and time in the clockwise direction are set equal to the rotational speed and time in the counterclockwise direction.

The die may be configured to be able to move up and down at the same time as the rotation of the rotating device. The electrolyte may be uniformly impregnated on the left and right sides with respect to the vertical direction of the battery cell by the rotational motion of the rotating device, The electrolyte can be uniformly impregnated in the upper and lower portions of the battery cell by the up and down movement.

The present invention also provides a method for impregnating an electrolyte solution by using the electrolyte impregnation system,

(a) injecting an electrolyte into the battery cell;

(b) positioning the battery cell into which the electrolyte is injected, in the chamber;

(c) a vacuum process for depressurizing the atmosphere inside the chamber;

(d) a pressing process of applying pressure to both sides of the battery cell; And

(e) rotating the battery cell;

≪ / RTI >

When the battery cell in which the electrolyte is injected is placed in the chamber and then the inside of the chamber is evacuated, as described above, the battery cell is housed in a chamber located at a specific place, The process of storing the battery cells in all the chambers can be performed in a specific place by repeating the process of rotating the battery cells and storing the battery cells in another chamber adjacent to the chamber in which the battery cells are housed.

The present invention also provides a method for impregnating an electrolyte solution by using the electrolyte solution impregnation system,

(a) positioning a battery cell inside a chamber;

(b) a vacuum process for depressurizing the atmosphere inside the chamber;

(c) injecting an electrolyte into the battery cell;

(d) a pressing process of applying pressure to both sides of the battery cell; And

(e) rotating the battery cell;

≪ / RTI >

The second electrolyte impregnation method is different from the first electrolyte impregnation method in which an electrolyte is injected after a vacuum process and a vacuum process is performed after injecting an electrolyte.

When the inside of the chamber is decompressed to be in a vacuum state and the electrolyte solution is injected into the battery cell, the electrolyte impregnation performance is relatively improved as compared with the first electrolyte impregnation method. After the electrolytic solution impregnation process, There is an effect that the necessary storage time is shortened before moving on to.

Further, according to the first electrolyte solution impregnation method, since the electrolyte solution impregnation system having one fixed electrolyte solution injecting apparatus is used, the rotation of the die is required to inject the electrolyte solution into all the battery cells, while the second electrolyte solution According to the impregnation method, since the electrolytic solution is injected in a state where the battery cells are located inside the respective chambers by using the electrolyte solution impregnation system having a plurality of electrolyte injection apparatuses connected to the plurality of chambers, a process of rotating the die is unnecessary .

In the first and second electrolyte solution impregnation methods, each of the steps (d) may proceed when the height of the electrolyte reaches a certain level or more. When the height of the electrolyte injected into the battery cell is too high, It is preferable that the height of the electrolytic solution at a predetermined level or higher is 0.5 mm to 20 mm smaller than the height of the built-in electrode assembly, considering that the electrolytic solution can flow out when the cell is pressurized and if it is too low, complete impregnation is difficult.

In the first and second electrolyte solution impregnation methods, the respective steps (e) can be repeated in the same number of rotations in the clockwise direction and the counterclockwise direction. In order to uniformly impregnate the entire inside of the battery cell It is preferable that the clockwise direction and the counterclockwise direction are repeatedly rotated and the clockwise rotation speed and rotation time are set to be equal to the counterclockwise rotation speed and rotation time.

Meanwhile, in the first and second electrolyte infiltration methods, each of the steps (e) can be performed simultaneously with the vertical movement of the die mounted with the chamber, so that the electrolytic solution inside the battery cell And the electrolytic solution can be uniformly impregnated into the upper and lower ends of the battery cell by the vertical movement of the die.

In the step (d) of the second electrolyte solution impregnation method, the pressing process and the pressure reducing process can be repeatedly performed 5 to 20 times, and the number of times can be adjusted in consideration of the size and thickness of the battery cell , And the process (d) for all the chambers may be performed in the same process. Alternatively, when the sizes of the battery cells housed in the respective chambers are different, the pressurization process and the decompression process times of the respective chambers may be set to be different from each other.

The present invention also provides a battery cell manufactured by the method according to the electrolyte injection method, and provides the battery pack including the battery cell.

The battery pack may be used as a power source for devices requiring high temperature stability, long cycle characteristics, and high rate characteristics.

Specific examples of the device include a power tool which is powered by an electric motor and moves; An electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and the like; An electric motorcycle including an electric bike (E-bike) and an electric scooter (E-scooter); An electric golf cart; And a power storage system, but the present invention is not limited thereto.

INDUSTRIAL APPLICABILITY As described above, the electrolyte impregnation system according to the present invention includes both a pressurizing device and a rotating device. In addition to improving the permeability of the electrode and the separator, the electrolyte solution can be uniformly spread over the electrodes and the separator. The impregnability of the electrolyte solution can be improved.

In addition, in the case of including the die moving up and down together with the rotation of the rotary device in the left and right directions, it is possible to provide the battery cell in which the electrolyte is uniformly impregnated throughout the battery cell.

1 is a plan view of an electrolyte immersion system according to one embodiment;
Figure 2 is a perspective view of the electrolyte immersion system of Figure 1;
3 is a vertical cross-sectional view taken along line A-A 'in Fig. 1; And
4 is a plan view of an electrolyte immersion system according to another embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

FIG. 1 schematically shows a planar structure of an electrolyte solution impregnating system according to one embodiment of the present invention. FIG. 2 is a perspective view of a structure in which an electrolyte solution injecting apparatus and a pressure reducing apparatus are omitted in the electrolyte solution impregnating system of FIG. And FIG. 3 schematically shows a vertical sectional view taken along the line A-A 'in FIG.

1 to 3, an electrolyte solution impregnation system according to the present invention includes an electrolyte solution injecting apparatus 110, a pair of pressurizing apparatuses 111 and a rotating apparatus 112 for injecting an electrolyte solution into a battery cell 101, Four pressure chambers 120, 130, 140 and 150, a pressure reducing device 113, and a die 160 equipped with chambers.

Although the die 160 is shown in a circular shape in a plan view, the die 160 can be rotated to be horizontal with respect to the ground when the chamber is mounted on the upper surface. If the structure is vertically movable in the vertical direction with respect to the ground, It does not need to be. The chambers 120, 130, 140 and 150 are located at the outer periphery of the die 160 except for the central portion 161 where the central axis 162 is formed have. The number of the chambers is not particularly limited, but may be preferably three to twelve.

The size of the chambers 120, 130, 140, 150 may be equal to or different from each other depending on the size of the battery cells accommodated, and the distance between the center of the chambers and the central axis 162 All are constant.

One or two or more battery cells 101 are accommodated in the chambers 120, 130, 140 and 150, and a surface on which electrode terminals (not shown) are formed may be housed so as to face the upper surface The lamination direction of the battery cells is not particularly limited except that the case where a plurality of battery cells are stacked and the battery cells are all stacked in a predetermined direction except that the side where the electrode terminals are formed faces downward .

A pair of pressure devices 111 are positioned adjacent to the battery cells on the outer side of each of the outermost battery cells with respect to the battery cells 101. The amount of the electrolyte injected reaches a certain level And moves in the direction of the battery cell 101 to apply pressure to the battery cell.

At this time, in order to transmit an equal pressure to the entire battery cell, it is preferable that the area of the pressing device facing each other is formed larger than the size of the side surface of the battery cell.

The battery cells 101 and the pair of pressurizing devices 111 are located at the center of the upper surface of the rotating device 112. The rotating device 112 is disposed on the basis of a virtual rotational axis 119 passing through the center of the battery cells. , The battery cells are rotated.

At this time, the rotational speed and / or the rotation time of the rotating device 112 can be set individually in consideration of the size and thickness of the battery cells housed in the chamber, as well as individual settings.

The rotating device 112 repeats the clockwise rotation and the counterclockwise rotation several times. This is because, when rotating in only one direction, uniform impregnation of the electrolytic solution can be prevented.

The rotation of the rotating device 112 provided in each of the chambers 120, 130, 140, and 150 can be simultaneously performed with the vertical movement of the die 160, So that the electrolyte impregnation rate can be further improved.

FIG. 4 schematically shows a plan view of an electrolyte solution impregnating system according to another embodiment of the present invention.

4, each of the chambers 220, 230, 240, and 250 may include a plurality of chambers 220, 230, 240, and 250 for injecting an electrolyte after reaching a vacuum state in a state where battery cells are accommodated between pressurizing devices in the respective chambers. The apparatuses 211, 212, 213, and 214 are different in that they have a plurality of electrolyte injection apparatuses as compared with the electrolyte solution impregnating system of FIG.

However, after the electrolyte solution is injected, the rotation and the movement by the rotating device and the die are performed in the same process as the electrolyte solution impregnating system of Fig.

Therefore, when the electrolyte impregnation system and the electrolyte impregnation method according to the present invention are used, not only the rate of electrolyte impregnation due to reduced pressure is increased but also the movement of the electrolyte in the horizontal direction by the rotating device and the movement of the electrolyte in the vertical direction by the die The secondary battery is improved in cycle characteristics and lifespan characteristics of the battery because the electrolyte is uniformly impregnated in the entire battery cell.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

An electrolyte injection device for injecting an electrolyte into the battery cell;
One or more chambers in which a pressing device for pressing both sides of the battery cell and a rotating device for rotating the battery cell are provided inside the battery cell in order to enhance the impregnation property of the electrolyte solution in the state where the electrolyte solution is injected;
A decompression device for evacuating the interior of the chamber; And
A die having at least one chamber mounted thereon;
And an electrolyte solution containing the electrolyte solution. The electrolyte solution impregnating system according to claim 1, wherein the chambers are disposed in a detachable structure along an outer periphery of a die which is circular in a plane. The electrolyte impregnating system according to claim 1, wherein the number of chambers that can be mounted on the die is three to twelve. 2. The electrolyte impregnating system of claim 1, wherein the die is equipped with a plurality of chambers of uniform size or varying sizes. The apparatus of claim 1, wherein the die is of a plate-like structure rotatable in parallel with the ground,
The chamber is configured such that n battery cells are sequentially stored from the first chamber to the nth chamber (n is a natural number of 3? N? 10)
Wherein the die rotates in one direction as the battery cells are sequentially housed in the chamber. The electrolyte solution impregnation system according to claim 1, wherein the pressure device is configured to press both sides of the battery cell when the height of the electrolyte reaches a certain level or more by a composition in a vacuum state. The electrolyte solution impregnating system according to claim 1, wherein the rotating device is configured to rotate the battery cell based on a rotation axis parallel to an electrode terminal projecting direction of the battery cell and passing through a center portion of the battery cell. The electrolyte impregnation system according to claim 1, wherein rotation speeds and / or rotation times of rotating devices provided in each of the chambers are individually settable. The electrolyte solution impregnating system according to claim 1, wherein the rotating device provides a repetitive rotational force in a clockwise direction and a counterclockwise direction to the battery cell. The electrolyte impregnating system according to claim 1, wherein the die is configured to be able to move up and down simultaneously with rotation of the rotating device. A method for impregnating an electrolyte solution using the electrolyte solution impregnating system according to any one of claims 1 to 10,
(a) injecting an electrolyte into the battery cell;
(b) positioning the battery cell into which the electrolyte is injected, in the chamber;
(c) a vacuum process for depressurizing the atmosphere inside the chamber;
(d) a pressing process of applying pressure to both sides of the battery cell; And
(e) rotating the battery cell;
Wherein the electrolyte solution is an electrolyte solution. A method for impregnating an electrolyte solution using the electrolyte solution impregnating system according to any one of claims 1 to 10,
(a) positioning a battery cell inside a chamber;
(b) a vacuum process for depressurizing the atmosphere inside the chamber;
(c) injecting an electrolyte into the battery cell;
(d) a pressing process of applying pressure to both sides of the battery cell; And
(e) rotating the battery cell;
Wherein the electrolyte solution is an electrolyte solution. The method according to claim 11 or 12, wherein the step (d) proceeds when the height of the electrolyte reaches a certain level or more. The method according to claim 11 or 12, wherein the step (e) repeats the same number of rotations in clockwise and counterclockwise directions. The method according to claim 11 or 12, wherein the step (e) is performed simultaneously with the vertical movement of the die on which the chamber is mounted. 13. The method according to claim 12, wherein the step (d) is repeatedly performed five to 20 times. A battery cell characterized by being manufactured by the method according to any one of claims 11 to 16. A battery pack comprising a battery cell according to claim 17.

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