KR20200128823A - Tray for Activating Battery Cell and Method for Manufacturing Thereof - Google Patents

Abstract

The present invention relates to a battery cell tray which is manufactured by a vacuum-molding method, and can also be used in an activation process unlike the conventional battery cell trays manufactured by the same method. Since the battery cell tray according to the present invention can be manufactured by the vacuum-molding method, cost and time can be reduced compared to a tray for a conventional activation process manufactured by injection molding. In addition, storage and removal of battery cells are easy, and defects such as stamping do not occur even when the thickness of the battery cells changes during the activation process, and stability is excellent even when a large amount of the battery cells are stored and transferred.

Description

[Tray for Activating Battery Cell and Method for Manufacturing Thereof}

The present invention relates to a battery cell tray for accommodating a battery cell in a battery cell activation process, and more specifically, to a battery cell tray manufactured by a vacuum forming method and a method of manufacturing a battery cell tray for an activation process using vacuum forming. .

As the price of energy sources rises due to the depletion of fossil fuels and interest in environmental pollution increases, the demand for eco-friendly alternative energy sources is becoming an indispensable factor for future life. In particular, technology development for mobile devices As the demand and demand increase, the demand for secondary batteries as an energy source is rapidly increasing.

Typically, in terms of the shape of the battery, there is a high demand for prismatic secondary batteries and pouch-type secondary batteries that can be applied to products such as mobile phones with a thin thickness. In terms of materials, lithium-ion batteries with high energy density, discharge voltage, and output stability, There is high demand for lithium secondary batteries such as lithium ion polymer batteries.

Recently, a pouch-type battery having a structure in which a stack-type or stack/folding-type electrode assembly is embedded in a pouch-type battery case of an aluminum laminate sheet has attracted a lot of attention due to low manufacturing cost, low weight, and easy shape transformation. Is also gradually increasing.

The pouch-type battery cell accommodates a stack-type or stack-folding electrode assembly manufactured by stacking a positive electrode, a separator, and a negative electrode. Each of the positive and negative electrodes is electrically connected by electrode tabs, and electrode leads drawn out to the outside are connected to the electrode tabs.

The electrode assembly to which the electrode tab and the electrode lead are connected is accommodated in a pouch-shaped battery case, and then an electrolyte is injected. A pouch-type battery cell is manufactured by sealing the battery case while a part of the electrode lead is exposed to the outside.

On the other hand, the battery case of the pouch-type battery cell is formed in a pouch shape to facilitate processing, so that there are few restrictions depending on the size or shape of the electrode assembly, and the space inside the battery cell can be efficiently used. Accordingly, the pouch-type battery cell has high energy density and can be processed in various forms, and has recently been used in automobile batteries in various forms.

A typical lithium secondary battery undergoes an activation process in a battery manufacturing process, and the activation process is a process of applying a current to a predetermined voltage to an electrode assembly impregnated with an electrolyte. During the initial charging/discharging process for activation, a protective film is formed on the surface of the electrode, and some electrolyte is decomposed to generate a large amount of gas.

However, in the case of a pouch-type battery cell, since the activation process proceeds in a sealed state, a swelling phenomenon occurs in which the battery cell swells due to the generated gas. Accordingly, after charging and discharging, gas inside the battery cell is discharged through a degassing process and then sealed again to produce a finished product of the secondary battery.

Referring to FIG. 1, the pouch-type battery cell 10 assembled before the activation process houses an electrode assembly 11 therein, and an electrode lead 12 connected to the electrode assembly is drawn out of the battery case. In this state, a battery cell is manufactured by fusing the excess part around the outer periphery of the pouch.

At this time, the sealing portion 13 formed by fusion bonding the excess portion is thinner than the portion where the electrode assembly 11 is accommodated, and thus the portion where the electrode assembly 11 of the pouch-type battery cell is accommodated and the sealing portion 13 There is a step difference between them.

Meanwhile, the assembled pouch-type battery cell undergoes an activation process through charging and discharging while being accommodated in a battery cell tray. However, in the pouch-type battery cell, since gas is generated inside the battery cell during the activation process as described above, thickness change inevitably appears. Therefore, the battery cell tray used in the activation process must be manufactured in response to the thickness change of the battery cell during the activation process.

In this regard, Korean Patent Publication No. 2008-0007854 (Patent Document 1) proposes a battery cell tray for an activation process.

The battery cell tray has an open top so that the battery cells can be inserted vertically, and the width of the inner wall of the tray accommodating part is designed to be larger than the thickness of the battery cell so as to respond to changes in the thickness of the battery cell. However, in this case, since the inserted battery cell may be tilted or collapsed, the pusher panel interviews the battery cell from both sides and supports the battery cell so that it does not collapse. The pusher panel is equipped with a spring, and the spring length changes even when the thickness of the battery cell is changed and a constant pressure is continuously applied to the battery cell, thereby maintaining the battery cell from inclining or falling.

The battery cell tray for the conventional activation process is specially designed to cope with the change in thickness, and has a variety of parts and a complex structure compared to a conventional tray, and each part is manufactured by injection molding and then undergoes an additional assembly process. Completed. Therefore, there is a disadvantage in that the production cost of the tray is high and the manufacturing time is also long.

In addition, the conventional battery cell tray for the activation process is difficult to accommodate and remove compared to the general battery cell tray due to its complicated structure, and the positional deviation is easy to occur. Therefore, the mass transfer, assembly and inspection process of the battery cell after the activation process Inappropriate. Therefore, after the activation process, the battery cells are accommodated again in a separate battery cell tray having a simple structure, and the remaining processes are performed.

That is, in the post-activation process, a simple type of battery cell tray that is easy to receive and transport and that can stably maintain the storage state during transport is used. In this case, the tray used may be manufactured by a vacuum forming method.

The vacuum forming method is manufactured by applying a vacuum to a fabric extruded from a plastic material, and in this case, it is possible to mold into a desired shape using a mold having a desired shape. The tray manufactured by the vacuum forming method has the advantage that it is inexpensive and can be manufactured quickly, but has a disadvantage that it is impossible to manufacture a complex shape.

In addition, the conventional tray manufactured by the vacuum forming method is not suitable for use as a tray for the activation process, because the pouch-type battery cell expands during the activation process, causing defects such as stamping on the exterior. Even if the width of the storage part is designed to be wide to cope with the expansion of the thickness of the battery cells, a fixing member for fixing is not separately provided, so during the transfer of the battery cells to complete the activation process and perform the degas process. The battery cells may be easily removed from the tray due to external shock, or the battery cells may be damaged due to high frequency flow while the cells are stored, resulting in damage to the appearance of the battery cells or damage to the internal components. .

Korean Patent Publication No. 2018-0007854 Korean Patent Publication No. 2018-0038181

The present invention is to improve the disadvantages of the tray for the activation process manufactured by the conventional injection molding, and to provide a tray for the activation process of the vacuum molding method and a manufacturing method thereof that can save cost and time compared to the prior art. do.

In order to achieve the above object, the battery cell tray of the present invention may include the following configuration.

The battery cell tray of the present invention is characterized in that it includes a mounting portion having an open top so that the battery cells can be inserted, and the mounting portion includes a curved fixing portion for fixing the battery cells.

In this case, the battery cells are vertically inserted into the mounting portion with respect to the bottom surface of the mounting portion, and the fixing portion is provided at least one pair on the inner surface of the mounting portion to fix the battery cells. Accordingly, the fixing portion may have a convex curved outer peripheral surface to contact the battery cell.

That is, the battery cell is vertically inserted from the open top of the mounting part, and the inserted battery cell lower end is fixed by a fixing part on the inner surface of the mounting part. A pair of fixing units are provided at the lower end of the inner side of the battery cell mounting unit to effectively fix the inserted battery cells on both sides. To this end, a distance between each of the pair of fixing portions may be gradually narrowed according to the direction in which the battery cells are inserted.

The fixing part is characterized in that it contacts one side of the battery cell inserted into the battery cell mounting part and the opposite side thereof. That is, after the battery cell is inserted into the mounting portion, one side and the opposite side of the battery cell are fixed while being in contact with the fixing portion on the inner side of the mounting portion.

At this time, the ratio of the thickness of the battery cell and the open width of the upper portion of the mounting portion is preferably 1: 1.1 to 1: 2. The upper part of the mounting part is open to insert the battery cell, in which case, the ratio of the open width of the upper part of the mounting part is based on the narrowest width of the inner side of the mounting part excluding the fixed part as shown in the side cross-sectional view of FIG. . If the ratio is less than 1:1.1, it may be difficult to insert the battery cell, and as the battery cell expands in the activation process, the battery cell itself may come out of the tray or defects such as stamping may occur. In addition, when the ratio exceeds 1:2, it may be difficult to fix the battery cell, and there is a risk that the battery cell may tilt or collapse during transport.

The ratio of the thickness of the battery cell and the open width of the upper portion of the mounting portion may be more preferably 1:1.3 to 1:1.5. It is more preferable in the case of the above range when considering the ease of storage of the battery cell and stability during the activation process and transport.

Meanwhile, the fixing part has a curved shape, and in this case, a radius of curvature of the fixing part may be 25 to 70 mm. If the radius of curvature is less than 25mm, a stamping phenomenon may occur as the battery cell expands during the activation process, and if the radius of curvature exceeds 70mm, the housed battery cell may be tilted or collapsed and may be separated from the tray.

On the other hand, when the radius of curvature of the fixing part is 35 to 50 mm, the appearance of the appearance does not appear even when the thickness of the battery cell is changed, and the battery cell is stably fixed to the tray, which is most preferable.

On the other hand, the battery cell tray of the present invention is characterized in that it is manufactured by a vacuum forming method. The battery cell tray of the present invention is composed of a mounting portion and a fixing portion provided on the inner surface of the mounting portion. Due to this simple structure, it is possible to manufacture by applying a vacuum to the extruded plastic fabric using a mold and molding it, and significantly reduce the manufacturing cost and manufacturing time compared to the battery cell tray for the activation process manufactured by conventional injection molding. I can make it.

In addition, the battery cell tray of the present invention is suitable for use in the battery cell activation process, and it is easy to receive and remove, and has excellent stability during transport, so that it can be used even after the activation process.

The battery cell tray for the activation process of the present invention may be manufactured through the following steps.

Extruding a plastic material;

A mounting part for housing a battery cell by vacuum forming the extruded fabric, and

Forming a curved fixing portion for fixing the battery cell.

That is, first, a plastic material suitable for the vacuum forming method and excellent in mechanical strength is melt-extruded and then molded while applying a vacuum using a mold.At this time, while forming the mounting part for accommodating the battery cell, The curved fixed portion having a predetermined radius of curvature may be formed by applying a vacuum in the same manner as the mounting portion. The mounting portion and the fixing portion may be formed sequentially by the vacuum forming, and the mounting portion and the fixing portion may be formed simultaneously in the vertical direction.

The plastic material for melt extrusion is preferably a synthetic resin in which one or two or more selected from the group consisting of polyethylene terephthalate, polystyrene, polypropylene, and acrylonitrile butadiene styrene (ABS) is used, but a material suitable for vacuum molding Ramen can be used in addition to the above materials. Therefore, the mounting portion and the fixing portion of the battery cell tray of the present invention may be made of the above-described material.

Unlike conventional vacuum forming trays, the battery cell tray manufactured by the above method does not cause problems such as stamping, pressing, and tray separation even when used in the activation process, and the battery cells do not tilt well even if the tray is transferred during the process. It is characterized by excellent stability. Therefore, when the battery cell activation process is performed using the battery cell tray according to the present invention, a battery cell of excellent quality can be obtained without defects in appearance or performance.

The battery cell tray according to the present invention can be utilized as a tray for an activation process of a battery cell, and can be manufactured by a vacuum forming method, thereby reducing cost and time. In addition, storage and removal of the battery cells are easy, and defects such as stamping do not occur even when the thickness of the battery cells change during the activation process, and stability is excellent even when a large amount of battery cells are stored and transferred.

1 schematically shows the structure of a pouch-type battery cell.
2 is a front view schematically showing a state in which a pouch-type battery cell is accommodated in a conventional tray manufactured by a vacuum forming method.
3 is a side view schematically showing a state in which a pouch-type battery cell is accommodated in a conventional tray manufactured by a vacuum forming method.
4 is a plan view schematically showing a state in which a pouch-type battery cell is accommodated in a conventional tray manufactured by a vacuum forming method.
5 is a front view schematically showing a state in which a pouch-type battery cell is accommodated in a tray for an activation process of the present invention manufactured by a vacuum forming method.
6 is a side view schematically showing a state in which a pouch-type battery cell is accommodated in a tray for an activation process of the present invention manufactured by a vacuum forming method.
7 is a plan view schematically showing a state in which a pouch-type battery cell is accommodated in a tray for an activation process of the present invention manufactured by a vacuum forming method.
8 is a cross-sectional side view of the tray for the activation process of the present invention manufactured by the vacuum forming method and the width and length of the upper portion of the mounting portion.
9 is a perspective view schematically showing a tray for an activation process of the present invention manufactured by a vacuum forming method.
10 is a photograph of a battery cell in which appearance defects appear after an activation process is performed using a conventional vacuum forming tray.

In the present invention, various modifications may be made and various forms may be applied, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing each drawing, similar reference numerals are used for similar elements. In the accompanying drawings, the dimensions of the structures are shown to be enlarged than actual for clarity of the present invention. The terms used to describe various components are provided to aid understanding, and the components should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. For example, a first component may be referred to as a second component without departing from the scope of the present invention, and similarly, a second component may be named as a first component. Singular expressions include plural expressions unless the context clearly indicates otherwise.

As used throughout the specification of the present invention, terms such as "include" or "have" are intended to designate the existence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification. It is to be understood that the possibility of the presence or addition of other features, numbers, steps, actions, components, parts, or combinations thereof, or any further features, is not excluded in advance.

Further, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where there is another part in the middle. Conversely, when a part such as a layer, film, region, plate, etc. is said to be "under" another part, this includes not only the case where the other part is "directly below", but also the case where there is another part in the middle. In addition, in the specification of the present invention, the term "above" may include a case where it is disposed not only above but also below.

Throughout the specification of the present invention, "curvature" means the degree of curvature of an object. Therefore, if the object has a straight line shape, the curvature value becomes 0, and the larger the degree of curvature of the object, the larger the curvature value appears. Meanwhile, the "curvature radius" means the radius of a circle created by extending a curve, and has an inverse relationship with the curvature. In general, the unit of the radius of curvature is expressed in mm and also expressed as R.

For example, if the radius of curvature is 25 mm. It means that the radius of the circle created by extending the curve is 25mm. At this time, the curvature is 1/25mm, which is the reciprocal of the radius of curvature.

Hereinafter, the present invention will be described in detail.

The present invention is a battery cell tray used in a battery cell activation process for a secondary battery, specifically, a battery cell by charging and discharging during the activation process while reducing the manufacturing cost and manufacturing time of the tray compared to the conventional battery cell tray for the activation process. It provides a battery cell tray that does not cause problems such as stamping, pressing, dislocation from the tray, and poor removal even in expansion.

In addition, according to the manufacturing method of the present invention, it is possible to quickly manufacture a tray by a simple vacuum forming method compared to a tray for a conventional activation process that was manufactured by injection molding. Hereinafter, a battery cell tray and a method of manufacturing the same according to the present invention will be described in detail with reference to the drawings.

The battery cell tray of the present invention is a tray for accommodating a battery cell, particularly a pouch-type battery cell, and can be utilized from activation, inspection, assembly, and shipping of a battery cell during a secondary battery manufacturing process.

The pouch-type battery cell houses an electrode assembly in a pouch-shaped battery case. The electrode assembly may be a stack type or a stack-fold type in which a positive electrode, a negative electrode, and a separator are stacked, and is connected to a plurality of electrode tabs and an electrode lead drawn out of the battery cell.

Referring to FIG. 1, a pouch-type battery cell 10 has an electrode assembly 11 made of a positive electrode, a negative electrode, and a separator inside. An electrode tab is formed at an end of the electrode assembly, and the bundle of electrode tabs is connected to an electrode lead 12 drawn out of the battery cell 10.

In order to manufacture a pouch-type battery cell, the electrode assembly 11 is housed in a pouch-type battery case, an electrolyte is injected, and then the battery case is sealed with the electrode lead 12 exposed to the outside. After the electrode assembly 11 is accommodated, the excess part of the battery case is fused and sealed, and the fused excess part forms the sealing part 13.

The manufactured battery cell 10 is accommodated in a battery cell tray for an activation process. During the activation process, the battery cells are charged and discharged, and at this time, gas due to side reactions is generated inside the sealed battery cells. This gas causes a swelling phenomenon in which the battery case swells. Therefore, the battery cell tray used in the activation process must be able to cope with the thickness change of the pouch-type battery cell.

As the thickness of the battery cells accommodated in the tray changes, various defects such as pressing or stamping of the battery cells as shown in the picture of FIG. 10 or separation from the tray may occur.To prevent this, the conventional activation process used The battery cell tray is designed in a more complex structure than a conventional battery cell tray.

On the other hand, the battery cell tray, which is commonly used in processes other than the activation process, has a simple structure that is easy to receive and remove according to the size and thickness of the battery cell. Therefore, it is mainly manufactured by a vacuum forming method that has low manufacturing cost and can be manufactured quickly.

2 to 4 are front, side and plan views schematically showing a conventional battery cell tray manufactured by a vacuum forming method used in a conventional process.

First, looking at the front view of FIG. 2, the pouch-type battery cell 10 shown in FIG. 1 is accommodated in the battery cell tray 100. In the front of the battery cell tray, a trapezoidal groove is formed to facilitate the storage and removal of battery cells by the robot arm in an automated process.

Next, FIG. 3 is a schematic view of the battery cell 10 as viewed from the side when the battery cell 10 is accommodated in the tray of the battery cell 100. A battery cell mounting portion 110 with an open top to accommodate the battery cells is formed on the top of the battery cell tray, and has a shape corresponding to the external shape of the battery cell. On the other hand, since the portion of the battery cell in which the electrode assembly is accommodated and the sealing portion have a step, a groove corresponding to the battery cell sealing portion is formed under the mounting portion.

4 is a plan view from above of a state in which the battery cells 10 are accommodated in the conventional battery cell tray 100. The battery cell mounting portion 110 with an open top is designed to correspond to the thickness of the thickest portion of the battery cell 10 in which the electrode assembly is accommodated.

As shown in Figs. 2 to 4, the battery cell tray 100 manufactured by the conventional vacuum forming method has a groove-shaped mounting portion corresponding to the shape of the outer peripheral surface of the battery cell. Accordingly, the battery cells are stably kept in a storage state even when mass transfer after the battery cells are stored, and the battery cells are hardly inclined or detached from the tray.

However, the conventional battery cell tray manufactured by vacuum molding and vacuum molding is not suitable as a battery cell tray used during the activation process. This is because the activation process proceeds at a high temperature of 65 degrees Celsius or higher, and during this process gas is generated inside the sealed battery cell, resulting in a swelling phenomenon in which the battery cell expands. As a result of the experiment conducted by the present applicant, it was confirmed that the thickness of the pouch-type battery cell of 11.95 mm increases up to 15.72 mm during the activation process.

Therefore, when the activation process is performed using a conventional battery cell tray, due to the expansion and thickness increase of the battery cells, appearance defects may occur due to being taken or pressed as shown in the picture of FIG. 10. In addition, even if no stamping or pressing occurs, the battery cells accommodated in the tray may be detached from the tray as it expands by gas inside.

To prevent this phenomenon, a battery cell tray having a modified structure different from that of a conventional battery cell tray is used in the activation process. Patent Document 1 describes various methods of installing a separate fixing device inside, such as increasing the width of the open mounting portion sufficiently to correspond to the expansion thickness of the battery cell, and applying pressure from both sides with a pusher panel so that the battery cell is fixed vertically. Has been.

However, conventional battery cell trays for the activation process are manufactured by adding a fixing device to the storage unit and assembling, and for this purpose, it is necessary to precisely manufacture not only the tray but also the parts necessary for fixing the battery cell through injection molding. have. Accordingly, mold cost, injection cost, manufacturing time, and the like, are several times higher than that of a conventional tray manufactured by a vacuum molding method, and the manufacturing time is much longer. In addition, there was a problem of lowering productivity because two types of trays had to be separately manufactured by completely different processes.

The present invention is to overcome the above problems, and provides a tray for an activation process that can be manufactured by a vacuum forming method.

5 to 7 schematically show a front view, a side view, and a plan view of the battery cell tray 200 for an activation process according to the present invention.

First, looking at the front view of FIG. 5, a trapezoidal groove is formed in the front of the tray in order to facilitate storage and removal by the robot arm at the front. This point is similar to the conventional battery cell tray 100.

However, looking at the side view of FIG. 6, unlike the conventional battery cell tray 100, the battery cell tray 200 for the activation process of the present invention has a width of the mounting portion 210 so as to correspond to the thickness change of the battery cell 10. It is formed longer than the width of the mounting portion 110 of the conventional tray 100. In addition, a pair of fixing parts 220 are formed on the lower inner surface of the mounting part 210, and the fixing part 220 has an outer circumferential surface of a convex curved surface, and the vertically accommodated battery cell 10 The battery cell 10 is vertically fixed while contacting both sides. In addition, in order to effectively fix the inserted battery cell 10 on both sides, the pair of fixing parts 220 are formed in a form in which the distance of the curved surface facing each other according to the direction in which the battery cell 10 is inserted is gradually narrowed. have.

That is, the battery cell tray 100 of the present invention includes a mounting portion 210 whose upper portion is open so that the battery cells 10 can be vertically inserted; And a curved fixing part 220 for fixing the battery cell, wherein the fixing part 220 is provided with at least one pair on the inner surface of the mounting part 210. The battery cell 10 is vertically inserted from the open top of the mounting part 210, and both sides of the inserted battery cell are fixed by the fixing part 220 on the inner surface of the mounting part 210. For effective fixing, the fixing part 220 may be provided with a pair at the lower end of the inner side of the battery cell mounting part 210, and it is possible to provide two or more pairs as necessary.

The fixing part 220 is characterized in that it contacts one side of the battery cell 10 inserted in the battery cell mounting part 210 and the opposite side thereof. That is, after the battery cell 10 is inserted into the mounting portion, one side of the battery cell 10 and the other side facing each other are fixed while contacting the fixing portion 220 on the inner surface of the mounting portion.

7 is a plan view of the battery cell tray for the activation process of the present invention. At this time, the battery cell 10 is accommodated in the thickness of the battery cell and the open width of the upper part of the mounting part 210, and the thickest part of the battery cell 10 in which the electrode assembly is accommodated is in contact with the fixing part 220 Becomes.

At this time, the open width 211 of the upper part of the mounting part 210 is based on the narrowest width of the inner side of the mounting part excluding the part provided with the fixing part as shown in the side cross-sectional view of the tray cut in the AA' direction in FIG. . On the other hand, it is preferable that the ratio of the thickness of the battery cell and the open width of the upper portion is 1:1.1 to 1:2.

The upper part of the mounting part 210 is open for insertion of the battery cell, but if the ratio is less than 1:1.1, it may be difficult to insert the battery cell, and defects such as stamping, pressing, and detachment of the battery cell as the battery cell expand in the activation process This can happen. In addition, when the ratio exceeds 1:2, it may be difficult to fix the battery cell, and there is a risk that the battery cell may tilt or collapse during transport.

On the other hand, the ratio of the thickness of the battery cell and the open width of the upper mounting portion may be more preferably 1: 1.3 to 1: 1.5. It is more preferable in the case of the above range when considering the ease of storage of the battery cell and stability during the activation process and transport.

The fixing part 220 is characterized in that it has a curved shape. By making the outer circumferential surface of the fixing part 220 a curved shape, while fixing the battery cell 10 vertically, even if expansion occurs in the part of the battery cell 10 in contact with the fixing part 220, appearance defects of being stamped or pressed do not occur. Does not.

In this case, the radius of curvature of the fixing part 220 may be 25 to 70 mm. If the radius of curvature is less than 25mm, a stamping phenomenon may occur as the battery cell expands during the activation process, and if the radius of curvature exceeds 70mm, the housed battery cell may be tilted or collapsed and may be separated from the tray.

On the other hand, when the radius of curvature of the fixing part 220 is 35 to 50 mm, the appearance of the appearance does not appear at all even when the thickness of the battery cell is changed, and the battery cell is stably fixed to the tray, so it is most preferable.

The battery cell tray of the present invention is characterized in that it is manufactured by a vacuum forming method. The battery cell tray of the present invention consists of a mounting portion and a curved fixing portion provided on an inner surface of the mounting portion, and due to this simple structure, it can be manufactured by a vacuum forming method.

That is, the battery cell tray for the activation process of the present invention can be manufactured by manufacturing a simple mold and then applying a vacuum to the extruded plastic fabric and molding it, compared to the battery cell tray for the activation process manufactured by conventional injection molding. The manufacturing cost and manufacturing time can be greatly reduced.

In addition, the battery cell tray of the present invention is suitable for use in the battery cell activation process, and it is easy to receive and remove, and has excellent stability during transport, so that it can be used even after the activation process.

Specifically, the battery cell tray for the activation process of the present invention may be manufactured through the following steps.

Extruding a plastic material;

A mounting part for housing a battery cell by vacuum forming the extruded fabric, and

Forming a fixing portion for fixing the battery cell.

That is, first, a plastic material suitable for the vacuum forming method and excellent in mechanical strength is melt-extruded and then molded while applying a vacuum using a mold.At this time, while forming the mounting part for accommodating the battery cell, The fixed portion having a convex curved surface having a predetermined radius of curvature may be formed by applying a vacuum in the same manner as the mounting portion. For this purpose, the mold used when applying vacuum is sequentially manufactured by applying vacuum from one side of the fabric to form a circular protrusion of the fixed part and forming a U-shaped mounting part on the other side of the fabric. Is possible. Therefore, compared to general injection molding, the mold shape is also simple, and the manufacturing cost can be further lowered.

In this case, the fixing portion may be formed on the inner surface of the mounting portion and the outer surface may have a radius of curvature of 25 to 70 mm. The radius of curvature can be adjusted by changing the shape of the mold, and can be adjusted by using an additional jig to correspond to various radiuses of curvature.

The plastic material for the melt extrusion is preferably a synthetic resin in which one or two or more selected from the group consisting of polyethylene terephthalate, polystyrene, polypropylene, and acrylonitrile butadiene styrene (ABS) is used, but a material suitable for vacuum molding Ramen can be used in addition to the above materials. However, in general, in the case of a vacuum forming tray, since the mechanical strength is lower than that of injection molding, it is preferable to use a material having high rigidity when performing an activation process for a large amount of battery cells.

The battery cell tray of the present invention manufactured by the vacuum forming method as described above can be used in the activation process, unlike the conventional vacuum forming tray, can be manufactured at low cost in a short period of time, and appearance and performance after the activation process. It is possible to manufacture excellent battery cells without defects. Specifically, referring to the perspective view of the battery cell tray of the present invention shown in FIG. 9, the battery cell in which the internal fixing part is inserted is made of an internal structure so as to cope with the thickness expansion so that the appearance of the battery cell does not occur even during the activation process. It plays a role in stably supporting it so that it does not fall.

Hereinafter, examples will be described in detail to aid understanding of the present invention. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited by the following examples. The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art.

Manufacturing of test battery cells

A stack-type electrode assembly in which a positive electrode, a negative electrode, and a separator were stacked was prepared, stored in a pouch-type battery case, and an electrolyte was injected, and eight pouch-type test battery cells were manufactured in the same manner. The thickness of each battery cell was the same as 12 mm.

Example 1

A plastic material fabric was extruded using a synthetic resin made of polyethylene terephthalate and polystyrene. Two test battery cell trays having a width of 15.5 mm on an upper portion of the mounting portion and a radius of curvature of 25 mm in the fixed portion were manufactured using a previously prepared vacuum forming mold.

Example 2

A plastic material fabric was extruded using a synthetic resin made of polyethylene terephthalate and polystyrene. Using a mold for vacuum molding prepared in advance, two test battery cell trays having a width of 19.5 mm on the upper portion of the mounting portion and a radius of curvature of the fixed portion 40 mm were manufactured.

Comparative Example 1

A plastic material fabric was extruded using a synthetic resin made of polyethylene terephthalate and polystyrene. Using a mold for vacuum molding prepared in advance, two test battery cell trays having a width of 11.5 mm on the upper portion of the mounting portion and a radius of curvature of the fixed portion of 0 mm were manufactured.

Comparative Example 2

A plastic material fabric was extruded using a synthetic resin made of polyethylene terephthalate and polystyrene. Using a mold for vacuum molding prepared in advance, two test battery cell trays having a width of 19.5 mm on the upper portion of the mounting portion and a radius of curvature of the fixed portion 100 mm were manufactured.

Activation process test

After performing the activation process through charging and discharging for each of the Examples and Comparative Examples, after performing degas under 80°C, 1.5T, 5ch conditions, the battery cells of each Example and Comparative Example (2 each * 4 = 8) was confirmed whether or not defects occurred, and the results are shown in Table 1 below.

division Battery cell expansion thickness Imprinted, pressed Deviated or
Tilting phenomenon Example 1 14.19 14.99 none normal Example 2 14.72 14.02 none normal Comparative Example 1 13.98 15.28 none Leaving the top of the battery cell Comparative Example 2 15.72 14.77 none Tilting phenomenon

10: battery cell
11: electrode assembly
12: electrode lead
13: sealing part
100: tray (conventional)
110: mounting part
200: tray (invention)
210: mounting part
211: width of the upper part of the mounting part
220: fixed part

Claims (13)

It includes a mounting portion with an open top so that the battery cell can be inserted,
The battery cell tray, characterized in that the mounting portion is provided with a curved fixing portion for fixing the battery cell.
The method of claim 1,
A battery cell tray, characterized in that the battery cells are inserted in the mounting portion in a vertical direction with respect to a bottom surface of the mounting portion.
The method of claim 1,
The battery cell tray, characterized in that the fixing portion is provided with a pair on the inner surface of the mounting portion.
The method of claim 3,
A battery cell tray, characterized in that the distance between the curved surfaces facing each other of the fixing portions gradually decreases according to the direction in which the battery cells are inserted.
The method of claim 1,
The battery cell tray, characterized in that the fixing portion has a convex curved shape.
The method of claim 1,
The battery cell tray, characterized in that the fixing portion is in contact with one side of the battery cell inserted in the battery cell mounting portion and the opposite side thereof.
The method of claim 1,
The battery cell tray, characterized in that the ratio of the thickness of the battery cell and the open width of the upper portion of the mounting portion is 1: 1.1 to 1: 2.
The method of claim 1,
The battery cell tray, characterized in that the ratio of the thickness of the battery cell and the open width of the upper portion of the mounting portion is 1: 1.3 to 1: 1.5.
The method of claim 1,
Battery cell tray, characterized in that the radius of curvature of the curved surface of the fixing portion is 25 to 70mm.
The method of claim 1,
Battery cell tray, characterized in that the radius of curvature of the curved surface of the fixing portion is 35 to 50mm.
The method of claim 1,
The battery cell tray is a battery cell tray, characterized in that manufactured by a vacuum forming method.
The method of claim 1,
The battery cell tray is a battery cell tray, characterized in that used in the battery cell activation process.
A battery cell manufactured using the battery cell tray of claim 1.

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