KR20170059078A - Electrolyte Wetting Device Comprising Resonance Oscillation Applying Portion and Method of Manufacturing Battery Cell Using the Same - Google Patents

Abstract

The present invention relates to an apparatus for improving the wettability of an electrolyte in an electrode assembly composed of an anode, a cathode, and a separator. The apparatus includes a holder located on both opposite sides of a working battery cell, wherein an electrode assembly and an electrolyte are contained in a battery case, and fixing the working battery cell; and a resonance oscillation applying part for applying a resonance oscillation to the holder so that the electrolyte contained in the working battery cell can soak into the electrode assembly by resonance when the working battery cell is fixed to the holder.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic solution impregnation apparatus including a resonance vibration applying unit and a battery cell manufacturing method using the electrolytic solution impregnating unit.

More particularly, the present invention relates to an electrolyte-impregnating apparatus including a resonance vibration applying unit for applying a vibration to a holder for fixing a working battery cell so as to cause resonance of an electrolytic solution or an electrode assembly, and an electrolytic solution- And a battery cell manufacturing method.

As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. In recent years, interest in environmentally friendly energy and carbon dioxide reduction has increased, and demand for electric vehicles and hybrid electric vehicles has increased Accordingly, the size of the secondary battery tends to increase due to the necessity of a large capacity.

Generally, such a secondary battery is manufactured by mounting an electrode assembly inside a battery case and injecting an electrolyte solution. When the size and the volume of the unit battery are increased as described above, electrolyte wettability may be a problem.

Specifically, the bulky secondary battery is difficult to impregnate the electrolyte solution into the electrode assembly, the electrolyte is uniformly impregnated, the movement of electrons and lithium ions in the electrode does not progress smoothly, Lt; / RTI >

Therefore, in the prior art, impregnation of an electrolyte solution under a vacuum condition has been attempted to improve electrolyte impregnability. However, a large amount of cost is required for setting a vacuum condition. In recent years, Techniques to improve impregnability have been developed.

However, even when vacuum and pressure are applied to the working cell as described above, the electrolyte is not uniformly impregnated to the inside of the electrode, shortening the life of the completed battery cell, delaying the aging process to impregnate the electrolyte solution to the center, It was not a solution.

Therefore, there is a high need for a technique capable of mass-producing a secondary battery of excellent quality by uniformly impregnating the electrolyte solution in the battery cell while shortening the process by increasing the initial impregnating property.

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.

Specifically, an object of the present invention is to provide an electrolytic solution impregnating apparatus which includes a resonance vibration applying unit for applying a resonance vibration to a battery cell holder to resonate an electrolytic solution or an electrode assembly so as to prevent unevenness of electrolyte impregnation and improve impregnation speed .

Yet another object of the present invention is to provide a method of manufacturing a battery cell having a high yield rate by shortening the initial impregnation process and the aging process using the electrolyte impregnation device.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an apparatus for impregnating electrolyte in an electrode assembly comprising an anode, a cathode, and a separator,

A holder for fixing the working battery cell, the electrode assembly and the electrolyte being positioned on opposite sides of the working battery cell embedded in the battery case; And

A resonance vibration is applied to the holder so that the electrode assembly can be impregnated with the electrolytic solution by the resonance of the electrolytic solution or the electrode assembly built in the working battery cell while the working battery cell is fixed to the holder part;

And a control unit.

That is, the electrolyte-impregnating apparatus according to the present invention includes a resonance vibration applying unit for applying a resonance vibration so that the electrolyte solution or the electrode assembly resonates, thereby increasing the vibration amplitude of the electrolyte solution or the electrode assembly, To be impregnated.

Every object has at least one natural frequency that oscillates at a specific frequency. When a vibration having the same frequency (resonance frequency) as the specific natural frequency of an object is applied from the outside, the amplitude of the object is increased.

Increasing the amplitude of the object by the external vibration having the same frequency as the natural frequency of the object is called resonance or resonance. The present invention improves the impregnability of the electrolyte solution in the electrode assembly by using this resonance phenomenon.

Accordingly, the electrolyte solution impregnation apparatus according to the present invention includes a resonance vibration applying unit for inducing a resonance phenomenon of an electrolyte solution or an electrode assembly.

The resonance vibration applying unit may apply resonance vibration in a state of being in direct contact with the holder, or may apply resonance vibration by a specific medium.

In the case where the resonance vibration applying unit is in direct contact with the holder, the resonance frequency for resonance vibration is easily measured, and the error range is reduced, so that the electrolyte solution can be more effectively impregnated into the electrode assembly.

When there are a plurality of working battery cells, the resonance vibration applying portion may be in contact with each of the plate-like holders for fixing the working battery cells, and may be recessed in the lower surface direction from the above- Shaped holders of one or more of the above embodiments.

The electrolytic solution impregnating device in contact with each of the resonance vibration applying additive plate type holders applies vibration with minimum resistance so that it is preferable to impregnate electrolytic solution in each of the plurality of working battery cells uniformly.

The electrolytic solution impregnating device in which at least one resonance vibration applying part is contacted with the tray type holder can reduce the electrolyte impregnation property of the working battery cell located far from the epicenter of resonance vibration but the number of vibration applying devices can be reduced, .

Meanwhile, the electrolyte solution impregnating apparatus may further include a medium that mediates the resonance vibration applying unit and the holder.

In one non-limiting example, the medium may be a liquid medium.

When such a liquid medium is used, a part of the plate-like holder may be supported on the liquid medium, and resonance vibration may be transmitted to the holder by using one or more vibration applying devices to the liquid medium.

That is, the medium for transmitting the vibration in the vibration applying part can improve the electrolyte impregnability of the plurality of working battery cells using one vibration applying part, and can select a suitable material in consideration of the change in the frequency.

Therefore, as in the case of using the tray-type holder, the electrolytic solution impregnating apparatus including the additional medium has an advantage that a plurality of battery cells can be simultaneously vibrated by a small number of vibration applying apparatuses. However, An error may occur and it may be difficult to induce resonance of the electrolyte solution.

Therefore, in the case where a medium for mediating the resonance vibration applying unit and the holder is further included, it is preferable to select the natural frequency of the medium, the holder, the electrode assembly, and the electrolytic solution in consideration of all natural frequencies.

The resonance vibration applying unit, which is directly or indirectly in contact with the holder, induces resonance of the electrolyte or the electrode assembly, thereby improving the impregnation speed and efficiency of the electrolyte solution in the electrode assembly.

The resonance vibration applying unit may induce a resonance phenomenon by applying ultrasonic waves having a resonance frequency of the electrode assembly or a resonance frequency of the electrolyte.

At this time, the system of vibration is an electrode assembly or an electrolyte solution, and a resonance frequency capable of resonating the electrode assembly itself or the electrolyte itself is applied to assist impregnation of the electrode assembly of the electrolyte. The above method can be performed by measuring a natural frequency (= resonance frequency) of an electrode assembly or an electrolytic solution, and then measuring a change in frequency according to a change in the medium.

This resonance frequency can be experimentally determined by measuring the response of the electrode assembly or the electrolyte with various frequency ranges in the battery cell, which varies depending on the shape and configuration of the battery cell, the main liquid volume of the electrolyte, and the vibration method.

On the other hand, applying an ultrasonic wave having a specific frequency includes not only an ultrasonic wave having the same frequency as a specific frequency but also applying ultrasonic waves having a frequency different from a specific frequency.

This is because an ultrasonic wave having not only the same frequency as the natural frequency but also a frequency close to the natural frequency can induce a resonance phenomenon.

The resonance vibration applying unit may induce a resonance phenomenon by applying ultrasonic waves having a resonance frequency of the electrode assembly and a resonance frequency of the resonance frequency of the electrolyte. At this time, the resonance frequency of the battery case can be taken into consideration.

Since the resonance frequency is substantially equal to the resonance frequency of the working battery cell, when the vibration having the resonance frequency is applied, the electrolyte solution and the electrode assembly simultaneously resonate, and the electrolyte solution is impregnated uniformly and rapidly to the electrode assembly.

On the other hand, the resonance vibration applying unit may induce a resonance phenomenon by applying a resonance frequency of the electrode assembly or a resonance frequency of the electrolyte.

The resonance vibration may be applied once or more than once, periodically or non-periodically.

The electrolyte solution impregnating apparatus may further include a vacuum pump for adjusting the vacuum pressure around the working battery cell to assist impregnation of the electrolyte solution in the electrode assembly.

As described above, the electrolytic solution impregnating apparatus according to the present invention can extremely improve the electrolytic solution impregnating speed and efficiency by using a resonance vibration applying unit together with a vacuum pump, a pressurizing unit, and an apparatus for assisting other electrolytic solution impregnation.

Meanwhile, the working battery cell may have a structure in which an electrode assembly is embedded in a pouch-shaped case made of a laminate sheet including a resin layer and a metal layer.

Specifically, the pouch type case may include an outer coating layer for protecting the cell from the outside, a metal layer for obtaining a predetermined mechanical strength, and a resin layer for ensuring durability and moisture resistance and forming a sealing portion.

The electrode assembly is not particularly limited as long as it is a chargeable and dischargeable power generation device composed of a lamination structure of a positive electrode / separator / negative electrode. The electrode assembly is a jelly-roll type in which a separator is interposed between a positive electrode and a negative electrode coated with an active material, A plurality of unit cells stacked in a state in which a plurality of positive electrodes and a plurality of negative electrodes of the unit cells are stacked in a state of being interposed in a separating film or stacked in a state in which a predetermined unit of positive and negative electrodes are stacked with a separating film interposed therebetween, It can be stacked / folded in one structure.

The present invention also provides a method of manufacturing a battery cell using the electrolyte impregnating apparatus.

In the above manufacturing method,

(i) a process of accommodating an electrode assembly in a battery case and injecting an electrolytic solution in a state where the electrode assembly is fixed to a holder to manufacture a working battery cell;

(ii) a step of operating a vacuum pump to convert the periphery of the working battery cell to a vacuum state; And

(iii) applying ultrasonic waves having the resonance frequency of the electrode assembly or the resonance frequency of the electrolyte to the working battery cell;

.

Specifically, in the above-described process (i), the electrode assembly is housed in the battery case, and the outer periphery excluding the part for injecting the electrolyte is first sealed (sealed), then fixed to the holder, and the electrolyte is injected.

Next, in the process (ii), the vacuum pump is operated to convert the periphery of the cell to a vacuum state. This vacuum state conversion process is performed in the chamber to prevent the inflow of outside air, and may be performed once or twice or more periodically or aperiodically with a vacuum pressure in the range of 0 KPa to -98 KPa.

In the step (ii), the electrolyte solution can easily penetrate the electrode assembly, and the processing cell can be pressed from the outside so that the electrolyte can be impregnated more quickly, if necessary.

Next, in step (iii), ultrasonic waves having a resonance frequency of the electrode assembly or a resonance frequency of the electrolyte are applied to the working battery cell.

In the step (iii), the electrolytic solution or the electrode assembly is resonated and the electrolytic solution impregnation rate is increased. This resonance process is performed under a predetermined vacuum and pressurized condition, thereby improving the impregnability of the electrolytic solution more efficiently.

After the step (iii), it may include an aging step (iv) for leaving the working battery cell.

This aging process is an additional step of allowing the remaining electrolytic solution to be impregnated into the working battery cell. In the case of using the electrolyte solution impregnation device according to the present invention, the initial impregnation property of the electrolytic solution is maximized by the resonance vibration, so that the time of the process (iv) can be shortened as compared with the conventional method of manufacturing the battery cell.

After the step (iv), the battery cell is completed by performing a charging / discharging process, a degassing process, and a sealing process for activation.

The present invention also provides a battery cell manufactured using the battery cell manufacturing method and a battery pack including at least one battery cell.

The battery cell or the battery pack is sufficiently impregnated with the electrolytic solution to the center of the electrode assembly and exhibits excellent battery characteristics. Therefore, the battery cell or the battery pack can be used as a power source for devices having high capacity and high output characteristics as well as small devices.

Specific examples of the device include a small device such as a computer, a mobile phone, a power tool, a power tool powered by an electric motor, 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; Power storage systems, and the like, but are not limited thereto.

The structure of these devices and their fabrication methods are well known in the art, and a detailed description thereof will be omitted herein.

As described above, the electrolyte-impregnating apparatus according to the present invention includes the resonance vibration applying unit that improves the impregnating property of the electrolyte solution by resonance, thereby increasing the initial impregnation speed of the electrolyte solution, So that it is possible to reduce the process cost and time, and to provide a high-output, high-capacity battery cell.

1 is a front view schematically showing an electrolyte solution impregnating apparatus according to one embodiment of the present invention;
2 is a front view schematically showing an electrolyte solution impregnating apparatus according to another embodiment of the present invention;
3 is an enlarged view schematically showing a part of a battery cell manufacturing process using the electrolyte impregnating apparatus of FIG.

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 front view of an electrolyte solution impregnating apparatus according to an embodiment of the present invention.

1, the electrolyte solution impregnating apparatus 100 includes plate-shaped holders 111, 112, 113, 114, 115, and 116 for fixing the working battery cells 201, 202, 203, 204 and 205, A vibration applying unit 120, and a vacuum pump 130. [

The resonance vibration applying unit 120 includes the vibration generating devices 121, 122, 123, 124, 125 and 126 and a power source 129. The vibration generating devices are connected to the respective holders .

Therefore, in the vibration generator, the natural frequency of the electrode assembly or the natural frequency of the electrolyte is experimentally measured to apply vibration for resonance of the electrolyte solution or the electrode assembly.

By the resonance vibration, the electrolytic solution injected into each of the working cells 201, 202, 203, 204, and 205 uniformly penetrates into the electrode assembly.

FIG. 2 schematically shows a front view of an electrolyte solution impregnating apparatus according to another embodiment of the present invention.

2, the electrolyte solution impregnating apparatus 300 includes a tray-type holder 310 for fixing the working battery cells 401, 402, 403, 404, and 405, a resonance vibration applying unit 320, 330).

1, the tray-type holder 310 of the electrolyte solution impregnating apparatus 300 includes a supporting portion 317 formed horizontally with the ground, side walls 311, 312, 313 , 314, 315, 316).

A working battery cell 401 is positioned between the side walls 311 and 312 and a working battery cell 402 is located between the side walls 312 and 313. A working battery cell 403 A working battery cell 404 is positioned between the side walls 314 and 315 and a working battery cell 405 is located between the side walls 315 and 316.

1, the resonance vibration applying unit 320 of the electrolyte solution impregnating apparatus 300 is connected to the supporting unit 317 of the tray-type holder 310, so that a plurality of working battery cells can be impregnated at a smaller number than the side walls have.

Although the resonance vibration applying unit 320 is directly connected to the tray-type holder 310, there is a working battery cell near the vibration generating apparatus, and a working battery cell located far away.

Therefore, the electrolytic solution-impregnating device including the resonant vibration applying part having a smaller size than the side wall of the plate-like holder or the tray-type holder may be deteriorated in electrolytic solution impregnation property of the working battery cell located far from the vibration generating device. This also applies to the case where a medium for mediating the resonance vibration applying section and the holder is included.

Hereinafter, a process of injecting an electrolytic solution into the working battery cells using the electrolyte impregnation apparatus will be described in detail.

Fig. 3 shows a part of the electrolyte infiltration apparatus 100 of Fig. 1. Fig. 3 shows a part of the electrolyte infiltration apparatus 100 of Fig. 1, and includes a working battery cell 201, holders 111 and 111 for holding the working battery cell 201 at both sides of the working battery cell 201, 112 are schematically shown.

3, first, the electrode assembly 221 is stored in the battery case 211 of the working battery cell 201.

Except for the upper end of the battery case 211 in which the electrode assembly 221 is housed, is sealed, and an electrolyte is injected into an electrolyte injector (not shown) through an unsealed top.

A small part of the injected electrolyte penetrates into the electrode assembly, but hardly penetrates into the center portion before operating the electrolyte solution impregnation device.

When the vacuum pump is operated to switch the periphery of the working battery cell 201 to the vacuum state, the electrolytic solution is more easily impregnated into the electrode assembly by the vacuum pressure. The vacuum pressure is increased in the range of -60 KPa to -98 KPa, and the process of lowering is repeated three times.

Simultaneously with or after the above process, ultrasonic waves having resonance frequencies of the electrolyte solution or the electrode assembly are applied in the resonance vibration applying part 120 to improve the electrolyte impregnation speed.

The working battery cell 201 uniformly impregnated with the electrolytic solution until the interior thereof shortens the aging process for impregnating the remaining electrolyte solution, and is formed into a final battery cell by carrying out a charging / discharging process and a degassing process for activation.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (14)

An apparatus for improving wettability of an electrolyte solution to an electrode assembly comprising an anode, a cathode, and a separation membrane,
A holder for fixing the working battery cell, the electrode assembly and the electrolyte being positioned on opposite sides of the working battery cell embedded in the battery case; And
A resonance vibration is applied to the holder so that the electrode assembly can be impregnated with the electrolytic solution by the resonance of the electrolytic solution or the electrode assembly built in the working battery cell while the working battery cell is fixed to the holder part;
And an electrolyte solution containing the electrolyte solution. The electrolyte impregnating apparatus according to claim 1, wherein the resonance vibration applying unit applies resonance vibration in a state of being in direct contact with the holder. The electrolyte impregnating apparatus according to claim 1, wherein the electrolyte impregnating apparatus further comprises a medium that mediates a resonant vibration applying unit and a holder. The electrolyte impregnating apparatus according to claim 3, wherein the medium is a liquid medium. The apparatus according to claim 1, wherein the resonance vibration applying unit applies ultrasonic waves having a resonance frequency of the electrode assembly or a resonance frequency of the electrolyte. The electrolytic solution-impregnated device according to claim 1, wherein the resonance vibration applying unit applies ultrasonic waves having resonance frequencies of the resonance frequency of the electrode assembly and the electrolytic solution. The apparatus according to claim 1, wherein the resonance vibration is applied once, cyclically or non-periodically twice or more. The electrolyte-impregnating apparatus according to claim 1, wherein the electrolyte-impregnating apparatus includes a vacuum pump for adjusting the vacuum pressure around the working battery cell to assist impregnation of the electrolyte solution in the electrode assembly. The electrolytic solution-impregnating apparatus according to claim 1, wherein the working battery cell comprises a structure in which an electrode assembly is embedded in a pouch-shaped case made of a laminate sheet including a resin layer and a metal layer. A method of manufacturing a battery cell using the electrolyte solution impregnating apparatus according to any one of claims 1 to 9,
(i) a process of accommodating an electrode assembly in a battery case and injecting an electrolytic solution in a state where the electrode assembly is fixed to a holder to manufacture a working battery cell;
(ii) a step of operating a vacuum pump to convert the periphery of the working battery cell to a vacuum state; And
(iii) applying ultrasonic waves having the resonance frequency of the electrode assembly or the resonance frequency of the electrolyte to the working battery cell;
And forming a battery cell. 11. The method of claim 10, wherein the electrolyte solution or the electrode assembly is resonated by the process (iii) to increase the rate of impregnation of the electrolyte solution. The method for manufacturing a battery cell according to claim 10, comprising the step (iv) of aging the working battery cell after the step (iii). A battery cell manufactured using the battery cell manufacturing method according to claim 10. A battery pack comprising at least one battery cell according to claim 13.

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