KR20180007854A - Tray for activating of battery cell - Google Patents

Abstract

Provided is a tray capable of preventing a deviation in thickness, occurring during activation of battery cells. According to the present invention, the tray includes a battery cell mounting part having an opened upper portion to allow the battery cell to be vertically inserted. As at least one pair of spring-included pusher panels is mounted on the inner lateral side of the battery cell mounting part, one lateral side of the battery cell and the other side facing the same come in contact with the pusher panel when the battery cell is inserted into the battery cell mounting part.

Description

[0001] The present invention relates to a tray for activating a battery cell,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a tray for storing a battery cell, and more particularly, to a tray for storing and charging a battery cell charged and discharged in the process of activating the battery cell.

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. Generally, such a secondary battery can be classified into a cylindrical or rectangular can-type secondary battery and a pouch-type secondary battery depending on the exterior material or application form.

The secondary battery may be used in the form of a single battery cell or in the form of a battery module in which a plurality of unit cells are electrically connected to each other depending on the type of an external device used. For example, while a small device such as a cellular phone can operate for a predetermined time with the output and capacity of one battery cell, it is possible to use a portable computer such as a notebook computer, a portable DVD, a small personal computer (PC), an electric vehicle, BACKGROUND OF THE INVENTION [0002] Medium or large devices such as automobiles require the use of battery modules that include multiple battery cells due to their output and capacity issues.

The battery module is manufactured by connecting a protection circuit or the like to a core pack in which a plurality of unit cells are arranged in series and / or in parallel. When a prismatic or pouch-shaped battery is used as the unit cell, the electrode terminals can be easily manufactured by connecting the electrode terminals with a connecting member such as a bus bar after stacking the large-sized cells so as to face each other. Therefore, when a three-dimensional battery module having a hexahedral structure is manufactured, a prismatic or pouch-shaped battery is advantageous as a unit cell.

Meanwhile, the secondary battery is fabricated through a process of assembling cells and a process of activating the cells. In the cell activation stage, the battery cells are mounted on a tray and charge / discharge is performed under the conditions necessary for activation.

Fig. 1 shows a schematic view of a conventional tray.

Referring to FIG. 1, the tray 10 has a battery cell mounting portion 12 so that the battery cell 20 can be received therein. In the battery cell mounting portion 12, a clearance S is formed at the outer side of both sides of the battery cell 20 to accommodate the volume expansion of the battery cell 20 due to charging and discharging. In addition, the battery cell 20 is simply erected and kept so that no interference is given to each battery cell 20 during the activation period.

Since the battery cell 20 is safely stored because there is no interference with the battery cell 20, the electrolyte solution tends to fall under the battery cell 20 during the activation period as the electrode loading is increased and the electrolyte main liquid amount is increased recently. This results in a difference in wettability between the upper and lower portions of the vertically erected battery cell 20 and a thickness variation due to the difference in swelling degree. When the activation process of the battery cell 20 is performed in the tray 10, the battery cell 20 is expanded toward the free space S due to the generation of excess gas, The initial thickness of the battery cell 20 is increased. In addition, if the battery cell case or the electrode assembly is deformed such that the battery cell case or the electrode assembly is deformed, the original shape of the battery cell case or the electrode assembly is difficult to be restored.

Therefore, there is a high need for a battery cell having superior safety by solving the above problems and preventing or suppressing deformation of the battery cell. Conventionally, a method of adding a process such as a hot press has been studied. Alternatively, there is an attempt to newly manufacture the tray itself as a pressurized type. In both cases, however, the cost burden is imposed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a tray capable of preventing a thickness variation occurring in an activation process of a battery cell.

In order to accomplish the above object, a tray according to the present invention includes a battery cell mounting portion having an open upper portion for vertically inserting a battery cell, and at least a pusher panel having a spring is disposed on the inner side of the battery cell mounting portion. And one side of the battery cell and the opposite side face thereof are in close contact with the pusher panel when the battery cell is inserted into the battery cell mounting portion.

That is, the tray according to the present invention has a structure in which one side of the battery cell and the opposite side thereof are in close contact with the pusher panel of the battery cell mounting portion in order to suppress the expansion of the battery cell that occurs when the battery cell is inserted and discharged / . Therefore, the battery cell charging and discharging tray according to the present invention is formed in a structure that ensures the stability by preventing the increase in the volume of the battery cell that occurs when the battery cell is activated.

In the present invention, the battery cell may be a plate-shaped battery cell. In addition, the battery cell mounting portion may be formed in a structure corresponding to the outer shape of the plate-shaped battery cell so that the plate-shaped battery cell can be mounted. For example, the battery cell mounting portion may be formed in an elongated flat shape in which the plate-shaped battery cells are vertically inserted in a plane. The upper opening of the battery cell mounting portion is larger than the lower opening, so that insertion and removal of the battery cell can be facilitated. The distance between one side surface of the battery cell and the inner surfaces of the battery cell mounting portion facing the opposite side surfaces thereof may be 150% to 200% of the width of the battery cell. If the distance between the inner surfaces of the battery cell mounting portion is less than 150%, the installation of the pusher panel and the spring may not be easy. If the distance between the inner surfaces of the battery cell mounting portion is greater than 200%, the size of the tray itself may become undesirably large, which may be undesirable. The upper opening of the battery cell mounting portion may be 10% to 50% larger than the lower opening. If the size of the upper opening portion is too small, insertion and removal are not easy. On the contrary, if the upper opening portion is too large, the size of the tray itself becomes large due to unnecessary size.

One side of the battery cell may be a relatively wide side surface of the battery cell. In other words, since the wider side is liable to be deformed by expansion, the pusher panel can be formed in close contact with a wide side surface in order to effectively suppress deformation of the battery cell.

The battery cell may be a pouch-shaped battery cell having a structure in which an electrode assembly is embedded in a pouch-type sheathing material.

When the battery cell is inserted into the battery cell mounting portion, the pusher panel may be in close contact with the battery cell at a height of 75% or more from one side of the battery cell and the lower side of the opposite side thereof. It is possible to prevent the electrolyte solution from leaning below the battery cell which is erected and stored when the pusher panel is used, and it is possible to effectively prevent the occurrence of the thickness deviation due to the difference in the wettability depending on the position of the battery cell and the degree of swelling have.

The battery cell is not particularly limited as long as it is highly safe and can provide a high capacity. For example, the battery cell may be a lithium ion battery cell or a lithium polymer battery cell having a large energy storage amount per volume.

According to the present invention, it is possible to improve the impregnation by distributing the electrolytic solution inside the battery cell to the upper side of the erected battery cell during the activation process, and it is possible to reduce the battery cell thickness variation. Also, it is advantageous in terms of cost because it can be manufactured by modifying the existing tray without any special investment.

In addition, according to the present invention, it is possible to prevent expansion of the battery cell caused by activation of the battery cell, thereby preventing an increase in the volume of the battery cell, thereby improving stability.

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 is a schematic cross-sectional view of a conventional tray.
2 is a schematic cross-sectional view of a tray according to an embodiment of the present invention.
3 is a schematic cross-sectional view showing a structure in which a battery cell is mounted on the tray of FIG. 2;
FIG. 4 is a process flow chart schematically showing a battery cell manufacturing process which can be mounted on the tray of FIG. 2. FIG.
FIG. 5 illustrates an example of a wound electrode assembly included in a battery cell that can be mounted on the tray of FIG. 2. FIG.
FIG. 6 is a schematic view showing a method of injecting an electrolyte solution into a battery cell that can be mounted on the tray of FIG. 2;
7 is a top view of the completed state of the battery cell that can be mounted to the tray of FIG.
8 is a photograph of an experimental example of the present invention.

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 interpreted in accordance with the 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.

FIG. 2 is a cross-sectional view of a tray according to an embodiment of the present invention, and FIG. 3 illustrates a structure in which a battery cell is mounted on the tray of FIG. FIGS. 2 and 3 illustrate a tray for each unit of a battery cell, and the actual tray can be used for the purpose of accommodating a plurality of battery cells by arranging the unit trays in a plurality of rows and / or columns.

Referring to FIG. 2, a tray 100 is formed with a battery cell mounting portion 110 having an open top so that a plate-shaped battery cell can be inserted vertically. At least one pair of pusher panels 130 with springs 120 is mounted on the inner side of the battery cell mounting portion 110. The spring 120 may be disposed in an appropriate number and arrangement at an appropriate position with a modulus of elasticity such that even when the battery cell is inflated, a uniform pressure can be applied.

3, when the battery cell 200 is inserted into the battery cell mounting portion 110, one side of the battery cell 200 and the opposite side thereof are brought into close contact with the pusher panel 130 do. Therefore, it is structured to inhibit the expansion during the activation process.

The battery cell 200 may be a pouch-shaped battery cell in which an electrode assembly is embedded in a pouch-type sheathing material, and the side where the electrode lead of the electrode assembly is not drawn out is inserted downward. This will be explained in more detail below.

The pusher panel 130 may be in close contact with the battery cell 200 at a height h of 75% or more from one side of the battery cell 200 and the lower side of the opposite side thereof when the battery cell 200 is inserted into the battery cell mounting portion 110 . It is possible to prevent the electrolytic solution from leaning below the battery cell 200 that is erected and stored in the pusher panel 130. The difference in wettability between the upper and lower portions of the battery cell 200 in the inserted state, It is possible to effectively prevent the thickness deviation from occurring due to the difference in swelling degree.

The battery cell 200 may be a lithium ion battery cell or a lithium polymer battery cell having a large energy storage amount per volume, for example, as long as the secondary battery is highly safe and can provide a high capacity.

One side of the battery cell 200 may be a relatively wide side surface of the battery cell 200. In other words, since the wider side is more likely to be deformed due to the expansion, the pusher panel 130 may be closely attached to a wide side surface in order to effectively suppress deformation of the battery cell 200.

The battery cell mounting portion 110 may be a plastic synthetic resin, and the pusher panel 130 may be the same or similar material. The synthetic resin of the plastic material may be a synthetic resin containing one or more of synthetic resins of PET (polyethylene terephthalate), PS (polystyrene), PP (polypropylene) and ABS (acrylonitrile-butadiene-styrene). The surface of the pusher panel 130 may be coated with a coating layer of silicon or urethane to reduce the friction of the surface of the battery cell 200 when the battery cell 200 is inserted. It is preferable that the pusher panel 130 be designed so that no mark is formed on the battery cell 200 by the pusher panel 130 to maintain the merchantability. Since the silicone or urethane material has elasticity, the coefficient of friction with the battery cell 200 is greatly reduced, thereby preventing the occurrence of marks on the battery cell 200.

During the activation period, the pusher panel 130 can press the battery cell 200 at a constant pressure. When a predetermined pressure is applied to the battery cell 200, the electrolyte solution directed to the lower side of the battery cell 200 is raised to the upper end of the battery cell 200. As a result, the electrolyte inside the battery cell 200 is evenly distributed during the activation period. It is possible to improve impregnation of the battery cell 200 by mitigating electrolyte leakage and improving the distribution of the electrolytic solution. In particular, it helps to solve the problem of deviation due to the position of the battery cell 200, such as a part lying on the bottom side and an upper part.

As described above, the tray 100 according to the present invention has a structure in which one side of the battery cell 200 and one side of the battery cell 200 are stacked in order to suppress the expansion of the battery cell 200 generated when the battery cell 200 is inserted and charged / And the opposite side surface is in close contact with the pusher panel 130 of the battery cell mounting portion 110. [ Accordingly, the tray 100 according to the present invention is formed in a structure that secures stability by preventing an increase in the volume of the battery cell 200 that occurs when the battery cell 200 is activated. In the model developed as a conventional pressurized tray, it is necessary to newly manufacture the tray itself, but the cost of the present invention can be reduced because the conventional tray can be retrofitted.

When the battery cell 200 is a plate-shaped battery cell, the battery cell mounting portion 110 may be formed to have a structure corresponding to the outer shape of the plate-shaped battery cell so that the plate-shaped battery cell can be mounted. For example, the battery cell mounting portion 110 may be formed in an elongated flat shape in which the plate-shaped battery cells are vertically inserted in a plane.

As shown in FIGS. 2 and 3, the upper opening of the battery cell mounting portion 110 is larger than the lower opening, so that insertion and removal of the battery cell 200 can be facilitated. The distance d between the inner surfaces of the battery cell mounting portion 110 facing the one side surface of the battery cell 200 and the opposite side surfaces thereof may be 150 to 200% of the width of the battery cell 200 have. It is easy to install the pusher panel 130 and the spring 120 when the distance d between the inner surfaces of the battery cell mounting portion 110 facing the one side surface of the battery cell 200 and the opposite side surfaces thereof is smaller than 150% I can not. If the distance d between the inner surfaces of the battery cell mounting portion 110 facing the one side surface of the battery cell 200 and the opposite side surfaces thereof is greater than 200%, the size of the tray 100 itself becomes large due to unnecessary size May be undesirable. The upper opening of the battery cell mount 110 may be 10% to 50% larger than the bottom. If the size of the upper opening portion is too small, insertion and removal of the battery cell 200 is not easy. On the other hand, if the size of the upper opening portion is too large, the size of the tray 100 itself becomes large due to unnecessary size.

When the battery cell mounting portion 12 of the conventional tray 10 described with reference to FIG. 1 is directly used as the battery cell mounting portion 110, the cost burden is small. In this case, the sizes of the pusher panel 130 and the spring 120 are preferably set to satisfy the above-mentioned conditions.

FIG. 4 schematically shows a process flow chart of a method of manufacturing a battery cell 200 that can be mounted on a tray 100 according to an embodiment of the present invention as shown in FIG. 2. FIG. 200 of the present invention. 6 schematically shows a method of injecting an electrolyte solution into the battery cell 200. As shown in Fig.

4 to 6, first, the electrode assembly 210 is manufactured and stored in the pouch-type sheathing 220 (S10).

The electrode assembly 210 constituting the battery cell 200 has a structure in which a positive electrode plate, a separator, and a negative electrode plate are sequentially disposed, and at least one of the positive electrode plate, the separator, and the negative electrode plate is arranged. The positive electrode plate is manufactured by applying a positive electrode active material such as lithium manganese oxide to a positive electrode current collector in the form of aluminum foil, drying and pressing the negative electrode plate, and the negative electrode plate is formed by applying an anode active material such as a carbon active material to a copper foil- And is formed by pressing. The electrode assembly may be in the form of a so-called jelly-roll type in which a positive electrode plate and a negative electrode plate in the form of a roll are wound in a spiral form with a separator in the form of a roll interposed between the positive electrode plate and the negative electrode plate, It may be in the form of a king, but should be construed to include any structure known in the art.

The pouch-type sheathing member 220 is formed with a sealing portion for accommodating the electrode assembly 210 and a sealing portion for thermal fusion along the peripheral edge of the receiving portion. Preferably, the pouch-type sheathing member 220 may have a folded-back portion on one of the four corners where the upper portion of the pouch-shaped sheathing portion 220 overlaps with the lower portion thereof in order to improve the sealability and the sealing property. And a sealing part for fusion bonding may be formed.

For example, the pouch-type sheathing material is covered with an insulating film or a heat-sealable layer on the surface of the aluminum thin film, It is preferable that the fusing layer is made of modified polypropylene, and the insulating film is made of either nylon or polyethylene terephthalate.

The electrode assemblies 210 are drawn out to the outside from either one surface or two surfaces facing each other. Generally, the surface of the electrode assembly where the electrode leads are formed is not covered with the separator, but the cross-sectional structure in which the planar structures constituting the electrode assembly such as the electrode and the separator are laminated is exposed to the outside. For example, in the spiral wound type electrode assembly, the laminated structure of the electrode and the separator is exposed to the outside on the surface formed in a direction substantially perpendicular to the winding center axis, and the electrode lead protrudes. On the other hand, the surface formed in a direction substantially parallel to the winding central axis is covered with a separator. Hereinafter, the surface on which the electrode lead is formed in the electrode assembly for convenience of description is referred to as the upper surface or the lower surface of the electrode assembly where the laminated structure of the electrode and the separator is exposed.

The electrode leads 210c and 210d may be formed on an upper surface or a lower surface of the electrode assembly, and both the upper surface and the lower surface may be formed as shown in FIG. 5, the upper surface 210a of the electrode lead 210c protrudes and the lower surface 210b of the electrode lead 210d, which are located opposite to the upper surface and protrude from the electrode lead 210d, The structure is not covered with the separator but is exposed. 6, the side surface of the electrode assembly other than the upper surface 210a and the lower surface 210b of the electrode assembly 210 is connected to the main liquid port 220 of the pouch- (A).

Next, the sealing portion of the pouch-shaped sheathing material 220 is sealed (S20). At this time, only the sealing portions except for the opening forming region for electrolyte pouring are sealed to form an electrolyte main liquid port, and an electrolyte is poured through the main liquid port (S30). As described above, the electrolyte main liquid port is formed in the lateral direction of the electrode assembly 210 housed therein.

When the electrolyte solution is completed, the main liquid is sealed to form a resilient portion (S40), and the battery cell 200 is completed.

7 is a top view of the completed battery cell 200 showing the position of the sealing part 230 in step S20 and the position of the resealing part 240 in step S40.

The battery cell 200 is accommodated such that the resilient portion 240 is located above the tray 100 battery cell mounting portion 110 and the pusher panel 130 is positioned on the opposite side of the battery cell 200, Thereby pressing it.

Hereinafter, an experimental example will be described.

The thickness of the battery cell 200 (the sealing portion 230 and the resealing portion 240) was varied according to the difference between the main liquid amount and the storage method.

The purpose of the experiment is to confirm the battery cell thickness variation due to the difference between the main liquid amount and the storage method. The thickness variation is a difference between the thickness of the sealing portion 230 and the thickness of the resilient portion 240, and was measured with a vernier caliper by five battery cells 200 per condition.

All processes except storage after pouring were carried out in the same way.

Below are the experimental conditions and results.

As a storage method, a tray (comparative example) as shown in FIG. 1 and a storage box 300 (embodiment of the present invention) having a center partition 310 as shown in FIG. 8 were used. In both cases, the resealing part 240 is vertically erected so as to be positioned upward.

As summarized in Table 1, through comparison of Samples 2 to 4, battery cell thickness variation increased with an increase in the amount of electrolyte. It is considered that the electrolytic solution is mainly distributed below the battery cell due to the swelling difference depending on the amount of electrolyte.

The thickness variation of the battery cells stored in the storage box 300 is about 0.2 mm less than the battery cells stored in the conventional tray. The conventional tray is conventionally stored in the battery cell without any interference. On the other hand, the storage box 300 is stored in a state in which the partition 310 is placed between battery cells to receive interference between the battery cells (pressure), and the electrolyte solution is relieved from being biased below the battery cells. Since the partition 310 corresponds to the pusher panel of the tray according to the present invention, the tray of the present invention can also be expected to reduce the thickness variation due to the close contact of the battery cell.

As described above, according to the present invention, since the battery cells are closely contacted and pressurized, expansion of the battery cells caused by activation of the battery cells can be suppressed to prevent increase in the volume of the battery cells, .

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. It is intended that all changes and modifications that come within the meaning and range of equivalency of the claims, as well as all equivalents thereof, be within the scope of the present invention.

100: Tray
110: Battery cell mounting portion
120: spring
130: pusher panel
200: battery cell
210: electrode assembly
220: Pouch type exterior material
210c, 210d: electrode lead
230: sealing part
240: resealing part

Claims (5)

And a battery cell mounting portion having a top opened so that the battery cell can be vertically inserted,
At least one pair of pusher panels with springs is mounted on the inner side surface of the battery cell mounting portion,
Wherein when the battery cell is inserted into the battery cell mounting portion, one side surface of the battery cell and the opposite side surface thereof are in close contact with the pusher panel. The tray according to claim 1, wherein the battery cell is a plate-shaped battery cell. The tray according to claim 1, wherein one side of the battery cell is a relatively wide side surface of the battery cell. The battery pack according to claim 1, wherein the battery cell is a pouch-shaped battery cell having an electrode assembly embedded in a pouch-type sheathing material, and the electrode assembly is inserted with the electrode lead out of the electrode assembly in a downward direction . The tray according to claim 1, wherein the pusher panel is in close contact with the battery cell at a height of 75% or more from one side of the battery cell and a lower side of the opposite side thereof when the battery cell is inserted into the battery cell mounting portion.

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