JP2024515078A - Electrode assembly, manufacturing apparatus thereof, and manufacturing method thereof - Google Patents

Abstract

An electrode assembly manufacturing apparatus according to an embodiment of the present invention includes an electrode supplying unit that provides an electrode sheet on which a plurality of electrodes are formed; a separation membrane supplying unit that provides a separation membrane sheet that is folded when the electrodes are installed to cover the electrodes and be laminated with the electrodes; a table on which the electrodes are installed so as to have the separation membrane sheet folded between the electrodes to form the electrode assembly; a separation membrane guide that guides the folding direction of the separation membrane sheet; and a pair of upper coaters that apply adhesive to at least a portion of an upper portion of the electrodes installed on the table, wherein the separation membrane guide and the pair of upper coaters reciprocate linearly left and right based on the table, and the table is fixed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0124051 dated September 16, 2021 and Korean Patent Application No. 10-2022-0114323 dated September 8, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

The present invention relates to an electrode assembly, its manufacturing apparatus, and its manufacturing method, and more specifically to a Z-folded battery cell in which electrodes and a separator sheet are stacked, and to an electrode assembly that can prevent the electrodes from coming off from their fixed positions, its manufacturing apparatus, and its manufacturing method.

Typically, types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These secondary batteries are used not only in small products such as digital cameras, P-DVDs, MP3s, mobile phones, PDAs, portable game devices, power tools, and E-bikes, but also in large products that require high output such as electric vehicles and hybrid vehicles, as well as in power storage devices and backup power storage devices that store surplus generated power and renewable energy.

To manufacture such a secondary battery, the electrode active material slurry is first applied to the positive and negative electrode collectors to manufacture the positive and negative electrodes, which are then laminated on both sides of a separator to form an electrode assembly of a given shape. The electrode assembly is then placed in a battery case, the electrolyte is injected, and the case is sealed.

Electrode assemblies are classified into various types. For example, there are a simple stack type in which positive electrodes, separators, and negative electrodes are simply stacked in a crossed manner without manufacturing unit cells, a lamination and stack type (L&S) in which unit cells are first manufactured using positive electrodes, separators, and negative electrodes, and then stacked on top of each other, a stack and folding type (S&F) in which multiple unit cells are attached at a distance to one side of a long separator sheet and the separator sheet is repeatedly folded in the same direction from one end, and a Z-folding type in which multiple electrodes or unit cells are alternately attached to one side and the other side of a long separator sheet and the separator sheet is folded in a specific direction from one end and then folded in the opposite direction. Of these, the Z-folded type has a high degree of alignment and electrolyte impregnation and has been widely used in recent years.

However, in the past, in this Z-folding type, after stacking the electrodes and the separator sheet, a separate lamination process was not performed, and the electrodes and the separator sheet were not adhered to each other, resulting in a problem of the electrodes coming off from their designated positions. To solve this problem, a separate lamination process was performed after stacking the electrodes and the separator sheet, but because the total thickness of the laminate in which the electrodes and the separator sheet are stacked is thick, there was a problem that heat was not transferred to the inside of the laminate, reducing the adhesive strength. In addition, there was a problem that the electrodes came off from their designated positions during the process of transporting the laminate in order to perform this separate lamination process. This problem was exacerbated when the adhesive strength of the separator sheet itself was low due to the material of the separator sheet.

Therefore, there is a need to develop a battery cell assembly including a Z-folded electrode assembly that improves the performance of the battery cell while preventing the electrodes from falling out of their fixed positions, as well as a manufacturing apparatus and method for the same.

The problem to be solved by the present invention is to provide an electrode assembly in which electrodes and a separator sheet are stacked in a Z-folded manner, and which can prevent the electrodes from coming off from their fixed positions, as well as a manufacturing apparatus and method for the same.

The problems that the present invention aims to solve are not limited to those mentioned above, and problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings.

The electrode assembly manufacturing apparatus according to one embodiment of the present invention includes an electrode supplying unit that provides an electrode sheet on which a plurality of electrodes are formed; a separation membrane supplying unit that provides a separation membrane sheet that is folded when the electrodes are installed to cover the electrodes and laminated with the electrodes; a table on which the electrodes are installed so as to have the separation membrane sheet folded between the electrodes to form the electrode assembly; a separation membrane guide that guides the folding direction of the separation membrane sheet; and a pair of upper applicators that apply adhesive to at least a portion of the upper part of the electrodes installed on the table, and the separation membrane guide and the pair of upper applicators move linearly back and forth from the left to the right based on the table, and the table is fixed.

The electrode supply unit may include a first electrode supply unit to which a first electrode sheet on which a plurality of first electrodes are formed is provided; and a second electrode supply unit to which a second electrode sheet on which a plurality of second electrodes are formed is provided.

The pair of upper applicators includes a first upper nozzle and a second upper nozzle, the first upper nozzle can apply the adhesive to the upper part of the first electrode, and the second upper nozzle can apply the adhesive to the upper part of the second electrode.

The first upper nozzle and the second upper nozzle may be arranged on either side of the separation membrane guide.

The first electrode can be installed on a first region of the separation membrane sheet, and the second electrode can be installed on a second region of the separation membrane sheet.

When the first electrode is placed on a first region of the separation membrane sheet, the first upper nozzle can move linearly on the first electrode, and when the second electrode is placed on a second region of the separation membrane sheet, the second upper nozzle can move linearly on the second electrode.

When the first upper nozzle applies the adhesive to at least a portion of the upper part of the first electrode, the separation membrane guide can move linearly in a direction in which the separation membrane sheet covers the first electrode, and when the second upper nozzle applies the adhesive to at least a portion of the upper part of the second electrode, the separation membrane guide can move linearly in a direction in which the separation membrane sheet covers the second electrode.

The apparatus may include a lower applicator that applies the adhesive to the lower portion of the first electrode and the lower portion of the second electrode, respectively.

It may further include a first header that adsorbs the first electrode and places it in the first region; and a second header that adsorbs the second electrode and places it in the second region.

When the first electrode is adsorbed to the first header, the lower applicator applies the adhesive to the lower part of the first electrode, and when the second electrode is adsorbed to the second header, the lower applicator applies the adhesive to the lower part of the second electrode.

The device may further include a first transport device that transports the first electrode toward the table; and a second transport device that transports the second electrode toward the table.

The first transfer device includes a first groove that is open toward the first electrode, and the lower applicator applies the adhesive to the lower part of the first electrode through the first groove, and the second transfer device includes a second groove that is open toward the second electrode, and the lower applicator applies the adhesive to the lower part of the second electrode through the second groove.

A battery cell manufacturing method according to another embodiment of the present invention includes the steps of: cutting a first electrode sheet unwound from a first electrode supply unit to form a plurality of first electrodes; placing the separation membrane sheet unwound from a separation membrane supply unit on a table along a separation membrane guide; applying adhesive to the lower part of the first electrode with a lower coater; placing the first electrode in a first region of the separation membrane sheet; applying adhesive to the upper part of the first electrode with a first upper nozzle; and folding the separation membrane sheet in a folding direction guided by the separation membrane guide so that the second region of the separation membrane sheet covers the first electrode.

After covering the upper part of the first electrode, the method may further include cutting the second electrode sheet unwound from the second electrode supply unit to form a plurality of second electrodes; applying adhesive to the lower part of the second electrode by a lower coater; placing the second electrode in the second region of the separation membrane sheet; applying adhesive to the upper part of the second electrode by a second upper nozzle; and folding the separation membrane sheet in a folding direction guided by a separation membrane guide, so that the first region of the separation membrane sheet covers the second electrode.

The table is fixed, and the separation membrane guide, the first upper nozzle, and the second upper nozzle can move back and forth linearly relative to the table.

An electrode assembly according to another embodiment of the present invention in which electrodes and separator sheets are alternately stacked, the electrodes include a first electrode and a second electrode, the separator sheet has a zigzag shape formed by folding at least twice, the separator sheet is folded with the first electrode placed on the first region of the separator sheet, the second region of the separator sheet covers the first electrode, the separator sheet is folded with the second electrode placed on the second region, the first region of the separator sheet covers the second electrode, and an adhesive layer is formed between the electrodes and the separator sheet.

The adhesive layer may include a first adhesive layer and a second adhesive layer, the first adhesive layer being located between the lower part of the electrode and the separation membrane sheet, and the second adhesive layer being located between the upper part of the electrode and the separation membrane sheet.

The first adhesive layer and the second adhesive layer may each be formed by applying adhesive in the form of multiple dots.

A battery cell according to another embodiment of the present invention is a battery cell including the electrode assembly described above, and includes a battery case that houses the electrode assembly together with an electrolyte, and the adhesive layer dissolves in the electrolyte.

According to an embodiment, the present invention provides an electrode assembly in which electrodes and a separator sheet are stacked in a Z-folded manner and adhesive is pre-applied to the upper and lower parts of the electrode, a manufacturing apparatus for the same, and a manufacturing method for the same, which can prevent the electrode from coming off from its fixed position.

The effects of the present invention are not limited to those described above, and effects not mentioned will be clearly understood by those with ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings.

4 is a flowchart of a method for manufacturing an electrode assembly according to an embodiment of the present invention. 4 is a schematic diagram illustrating a state in which a first electrode is installed in a first region of a separator sheet in an electrode assembly manufacturing apparatus according to an embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a state in which an adhesive is applied to a lower portion of a first electrode in an electrode assembly manufacturing apparatus according to an embodiment of the present invention. 13 is a schematic view showing a state in which an adhesive is applied to a lower portion of a first electrode in an electrode assembly manufacturing apparatus according to another embodiment of the present invention. 4 is a schematic diagram illustrating a state in which a first upper nozzle applies adhesive to an upper portion of a first electrode while moving linearly in an electrode assembly manufacturing apparatus according to an embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a state in which a separator guide moves linearly and a second electrode is installed on a second region of a separator sheet in an electrode assembly manufacturing apparatus according to an embodiment of the present invention. FIG. 13 is a schematic diagram illustrating a state in which a second upper nozzle applies adhesive to an upper portion of a second electrode while moving linearly in an electrode assembly manufacturing apparatus according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of an electrode assembly according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a battery cell according to an embodiment of the present invention.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be implemented in a variety of different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts that are not relevant to the description will be omitted, and the same reference symbols will be used for identical or similar components throughout the specification.

The size and thickness of each component shown in the drawings are shown arbitrarily for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, the thicknesses are shown enlarged to clearly express multiple layers and regions. In the drawings, the thicknesses of some layers and regions are shown exaggerated for the convenience of explanation.

In addition, throughout the specification, when a part "comprises" a certain component, this does not mean to exclude other components, but means that it may further include other components, unless specifically stated to the contrary.

In addition, throughout the specification, "on a plane" means when the subject part is viewed from above, and "on a cross section" means when the subject part is cut vertically and viewed from the side.

The following describes a method for manufacturing a battery assembly according to an embodiment of the present invention.

Figure 1 is a flow chart of an electrode assembly manufacturing method according to one embodiment of the present invention. Figure 2 is a schematic diagram showing how a first electrode is installed in a first region of a separator sheet in an electrode assembly manufacturing apparatus according to one embodiment of the present invention.

The electrode assembly manufacturing apparatus according to one embodiment of the present invention includes an electrode supplying unit that provides an electrode sheet on which a plurality of electrodes are formed, a separation membrane supplying unit that provides a separation membrane sheet that is folded when the electrodes are installed to cover the electrodes and be laminated with the electrodes, a table on which the electrodes are installed so as to have the separation membrane sheet folded between the electrodes to form the electrode assembly, a separation membrane guide that guides the folding direction of the separation membrane sheet, and a pair of upper applicators that apply adhesive to at least a portion of the upper part of the electrodes installed on the table, and the separation membrane guide and the pair of upper applicators move linearly back and forth from the left to the right based on the table, and the table is fixed.

Referring to FIG. 1 and FIG. 2, the method for manufacturing an electrode assembly according to one embodiment of the present invention includes a step of cutting electrode sheets 1111 and 1121 to form an electrode 11 (S101); a step of placing a separator sheet 122 on a table 16 (S102); a step of applying adhesive to the bottom of the electrode 11 (S103); a step of placing the electrode 11 on the separator sheet 122 (S104); a step of applying adhesive to the top of the electrode 11 (S104); and a step of folding the separator sheet 122 to cover the electrode 11 (S105).

As a result, in the electrode assembly manufacturing method according to this embodiment, when the electrode 11 and the separator sheet 122 are stacked in a Z-folding manner, adhesive is applied to the top and bottom of the electrode 11, preventing the electrode 11 from coming off from its fixed position.

Below, each step shown in the flowchart in Figure 1 will be explained in detail with reference to Figures 2 to 7.

The electrode assembly manufacturing apparatus 1 according to one embodiment of the present invention includes electrode reels 111, 112 from which electrode sheets on which a plurality of electrodes 11 are formed are unwound; a separation membrane reel 121 from which a separation membrane sheet 122 is unwound, which is folded when the electrode 11 is placed, to cover the electrode 11 and be laminated with the electrode 11; a table 16 on which the electrode 11 and the separation membrane sheet 122 are placed; and a separation membrane guide 125 that guides the folding direction of the separation membrane sheet 122; and a pair of upper nozzles 17 that apply adhesive to at least a portion of the upper part of the electrode 11 placed on the table 16. The electrode reels 111, 112 are an example of the electrode supply unit described above, and the separation membrane reel 121 is an example of the separation membrane supply unit described above. Also, the pair of upper nozzles 17 are an example of the upper coater described above.

The electrode reels 111, 112 may include a first electrode reel 111 from which a first electrode sheet 1111 on which a plurality of first electrodes 1112 are formed is unwound; and a second electrode reel 112 from which a second electrode sheet 1121 on which a plurality of second electrodes 1122 are formed is unwound.

The electrode reels 111 and 112 are reels on which the electrode sheets 1111 and 1121 are wound, and the electrode sheets 1111 and 1121 are unwound from the electrode reels 111 and 112. Then, the electrode sheets 1111 and 1121 are cut to form the electrode 11. More specifically, according to this embodiment, the first electrode reel 111 is a reel on which the first electrode sheet 1111 is wound, and the first electrode sheet 1111 is unwound from the second electrode reel 111. Also, the second electrode reel 112 is a reel on which the second electrode sheet 1121 is wound, and the second electrode sheet 1121 is unwound from the second electrode reel 112.

Here, the electrode sheets 1111 and 1121 can be manufactured by applying a slurry of an electrode active material, a conductive material, and a binder onto an electrode collector, and then drying and pressing the slurry. However, the manufacturing method of the electrode sheets 1111 and 1121 is not limited thereto, and any method for manufacturing the electrode sheets 1111 and 1121 generally in the relevant technical field is included in this embodiment.

More specifically, the first electrode sheet 1111 and the second electrode sheet 1121 may contain electrode active materials having different polarities. That is, the first electrode 1112 and the second electrode 1122 are electrodes 11 having different polarities. As an example, if the first electrode 1112 is a positive electrode, the second electrode 1122 is a negative electrode. As another example, if the first electrode 1112 is a negative electrode, the second electrode 1122 is a positive electrode.

The separation membrane reel 121 is a reel on which the separation membrane sheet 122 is wound, and the separation membrane sheet 122 is unwound from the separation membrane reel 121. The separation membrane sheet 122 is then stacked with the electrode 11 formed by cutting the electrode sheets 1111 and 1121. Here, the electrode 11 and the separation membrane sheet 122 are stacked in a Z-folded manner. More specifically, in this embodiment, when the first electrode 1112 is installed on the separation membrane sheet 122, one side is folded to cover the first electrode 1112, and when the second electrode 1122 is installed, the other side is folded to cover the second electrode 1122. The separation membrane sheet 122 may be in a zigzag shape.

The table 16 can be stacked with the electrodes 11 and the separation membrane sheets 122 placed on the upper surface. More preferably, the upper surface of the table 16 is formed to be substantially flat, so that the electrodes 11 and the separation membrane sheets 122 can be stacked stably.

The table 16 may be disposed between the first electrode reel 111 and the second electrode reel 112. More specifically, the table 16 may be fixed between the first electrode reel 111 and the second electrode reel 112.

As a result, the electrodes 11 and the separation membrane sheet 122 are stacked on the table 16 while the table 16 is fixed, thereby further improving the alignment of the electrodes 11 and the separation membrane sheet 122.

The electrode assembly manufacturing apparatus 1 according to this embodiment may further include a first transfer device 141 that transfers the first electrode 1112 toward the table 16; and a second transfer device 142 that transfers the second electrode 1122 toward the table 16. Here, the first transfer device 141 may transfer the first electrode 1112 formed by cutting the first electrode sheet 1111 unwound from the first electrode reel 111 toward the table 16. In addition, the second transfer device 142 may transfer the second electrode 1122 formed by cutting the second electrode sheet 1121 unwound from the second electrode reel 112 toward the table 16.

As a result, in this embodiment, the first electrode 1112 and the second electrode 1122 can be transported on both sides of the table 16 via the first transport device 141 and the second transport device 142, respectively, making it easy to alternately stack the first electrode 1112 and the second electrode 1122 on the separation membrane sheet 122.

The electrode assembly manufacturing apparatus 1 according to this embodiment may include headers 151 and 152 that adsorb the electrode 11 and install it on the separation membrane sheet 122. More specifically, the headers 151 and 152 may further include a first header 151 that adsorbs the first electrode 1112 and installs it on the separation membrane sheet 122, and a second header 152 that adsorbs the second electrode 1122 and installs it on the separation membrane sheet 122. Here, the first header 151 and the second header 152 may each move linearly back and forth toward the table 16.

More specifically, the first header 151 can adsorb the first electrode 1112 transferred from the first transfer device 141 toward the table 16, and the second header 152 can adsorb the second electrode 1122 transferred from the second transfer device 142 toward the table 16. In addition, the first header 151 and the second header 152 can move linearly toward the table 16.

As a result, in this embodiment, the first header 151 and the second header 152 can move the electrode 11 above the table 16, allowing the electrode 11 to be stably installed on the separation membrane sheet 122.

In addition, the headers 151, 152 can be accurately installed at the desired position on the separation membrane sheet 122 placed on the table 16 by measuring the presence or absence of misalignment of the first electrode 1112 or the second electrode 1122 for each first electrode 1112 or second electrode 1122 and correcting the position as necessary. As a result, in this embodiment, the degree of alignment between the electrodes 11 and the separation membrane sheet 122 stacked and aligned on the table 16 can be further improved.

Referring to FIG. 2, in the electrode assembly manufacturing apparatus 1 according to this embodiment, the electrode 11 may be installed on the separator sheet 122 with adhesive applied to at least a portion of the lower surface of the electrode 11. More specifically, in this embodiment, adhesive may be applied to at least a portion of the lower surface of the electrode 11 when the electrode 11 is positioned on the transfer device 141, 142, or adhesive may be applied to at least a portion of the lower surface of the electrode 11 when the electrode 11 is adsorbed to the header 151, 152.

Figure 3 is a schematic diagram showing how adhesive is applied to the lower part of a first electrode in an electrode assembly manufacturing apparatus according to one embodiment of the present invention. Figure 4 is a schematic diagram showing how adhesive is applied to the lower part of a first electrode in an electrode assembly manufacturing apparatus according to another embodiment of the present invention.

Referring to FIG. 3 and FIG. 4, the electrode assembly manufacturing apparatus 1 according to this embodiment may include a lower nozzle 173 that applies adhesive to at least a portion of the lower surface of the first electrode 1112. More specifically, the lower nozzle 173 may apply adhesive to at least a portion of the lower surface of the first electrode 1112. As a result, a first adhesive layer 1710 may be formed on the lower surface of the first electrode 1112. Here, the lower nozzle 173 is an example of a lower coater.

As an example, referring to FIG. 3, when the first electrode 1112 is adsorbed to the first header 151, the lower nozzle 173 can apply adhesive to at least a portion of the lower portion of the first electrode.

As another example, referring to FIG. 4, the first transfer device 141a includes a first groove 141a' that is open toward the first electrode 1112, and the lower nozzle 173 can apply adhesive to at least a portion of the lower portion of the first electrode 1112 through the first groove 141a'. Here, the first transfer device 141a may be formed with at least one first groove 141a', and the multiple first grooves 141a' may be arranged spaced apart from each other. Also, as shown in FIG. 4, the first groove 141a' may extend along the width direction of the first electrode 1112, but is not limited thereto and may extend in various directions.

However, for the sake of convenience, this has been explained using the first electrode 1112 as an example, and the second electrode 1122 can be explained in a similar manner using the second header 152 or the second transport device 142.

As a result, the electrode assembly manufacturing apparatus 1 according to this embodiment has the advantage that adhesive can be applied to at least a portion of the lower part of the electrode 11 during the transportation process of the electrode 11, thereby improving the convenience and speed of the process.

Here, it is preferable that the adhesive is applied evenly to the lower part of the electrode 11. However, if the adhesive is applied to the entire surface of the lower part of the electrode 11, the amount of adhesive applied may be excessive. In such a case, the adhesive may flow to the outside of the separator sheet 122 and contaminate other parts, and the secondary battery may not be able to generate electricity smoothly when manufactured.

Therefore, in this embodiment, it is preferable that the adhesive be applied to the lower part of the electrode 11 using a spot application method in which the adhesive is applied in dots or a line application method in which the adhesive is applied in lines. That is, it is preferable that the first adhesive layer 1710 is formed in a spot pattern or a line pattern.

On the other hand, if the amount of adhesive applied is too small, the electrode 11 may not be fixed to the separator sheet 122 as the cell moves and may come off from its fixed position. Therefore, it is preferable that the spacing between the areas where the adhesive is applied is not too wide.

In addition, the adhesive can be applied to the surface of the electrode 11 in a minimum amount necessary to ensure adhesion between the electrode 11 and the separator sheet 122. In contrast, if the adhesive is applied directly onto the separator sheet 122, the separator sheet 122 may absorb a portion of the adhesive, and a larger amount of adhesive may need to be applied to ensure adhesion between the electrode 11 and the separator sheet 122.

Meanwhile, the adhesive can be dissolved in the electrolyte. More specifically, when the first adhesive layer 1710 formed on the lower part of the electrode 11 is immersed in the electrolyte, the adhesive contained in the first adhesive layer 1710 can be dissolved in the electrolyte. Here, dissolving the adhesive can mean that the adhesive is dissolved in the electrolyte. That is, it means that the area of the first adhesive layer 1710 formed on the lower part of the electrode 11 is reduced, or the first adhesive layer 1710 is completely removed, and no first adhesive layer 1710 remains on the lower part of the electrode 11.

For example, the adhesive may be an acrylate adhesive. In this embodiment, the adhesive is applied to the lower part of the electrode 11 as an acrylate adhesive, so that the adhesive can dissolve and enter the electrolyte contained in the final battery cell.

As a result, in this embodiment, the first adhesive layer 1710 can fix the electrode 11 to the separator sheet 122 during the manufacturing process, preventing it from coming off from its fixed position. In addition, the first adhesive layer 1710 dissolves in the electrolyte contained in the final battery cell, and does not interfere with the movement of lithium ions between the electrode and the separator, thereby further improving the performance of the battery cell.

Figure 5 is a schematic diagram showing how a first upper nozzle applies adhesive to the top of a first electrode while moving linearly in an electrode assembly manufacturing apparatus according to one embodiment of the present invention.

Referring to FIG. 5, the pair of upper nozzles 17 apply adhesive to at least a portion of the upper surface of the electrode 11. More specifically, the pair of upper nozzles 17 includes a first upper nozzle 171 that applies adhesive to at least a portion of the upper surface of the first electrode 1112 and a second upper nozzle 172 that applies adhesive to at least a portion of the upper surface of the second electrode 1122.

The first upper nozzle 171 and the second upper nozzle 172 may be arranged on both sides of the separation membrane sheet 122. That is, the first upper nozzle 171 can apply adhesive to at least a portion of the upper part of the first electrode 1112 before the upper part of the first electrode 1112 is covered by the separation membrane sheet 122 to form the second adhesive layer 1750. The second upper nozzle 172 can apply adhesive to at least a portion of the upper part of the second electrode 1122 before the upper part of the second electrode 1122 is covered by the separation membrane sheet 122, as described later in FIG. 7, to form the second adhesive layer 1750.

In addition, the pair of upper nozzles 17 can move linearly back and forth from side to side with respect to the table 16. That is, the pair of upper nozzles 17 can apply adhesive to at least a portion of the upper part of the electrode 11 while moving linearly from one side of the table 16 to the other side or in the opposite direction.

The adhesive applied from the pair of upper nozzles 17 can be described in the same manner as the adhesive applied from the lower nozzle 173 described above.

Here, the pair of upper nozzles 17 can reciprocate left and right simultaneously or individually with respect to the table 16. More preferably, the pair of upper nozzles 17 can reciprocate left and right simultaneously with respect to the table 16. For example, when the first upper nozzle 171 applies adhesive from one side of the table 16 to the other side as shown in FIG. 5, the second upper nozzle 172 can apply adhesive from the other side of the table 16 to one side as described later in FIG. 7.

As a result, in this embodiment, the process time for the adhesive application process using the pair of upper nozzles 17 is reduced, further improving process efficiency.

Figure 6 is a schematic diagram showing how a separator guide moves linearly in an electrode assembly manufacturing apparatus according to one embodiment of the present invention to install a second electrode on a second region of a separator sheet.

Referring to Figures 5 and 6, in this embodiment, the folding direction of the separation membrane sheet 122 is guided by the separation membrane guide 125. More specifically, the separation membrane guide 125 can move linearly back and forth to the left and right with respect to the table 16.

For example, the separation membrane guide 125 may have a form in which a pair of rolls are arranged horizontally, and the separation membrane sheet 122 may be inserted between the pair of rolls. However, the form of the separation membrane guide 125 is not limited to this, and any form that can control the folding direction of the separation membrane sheet 122 is included in this embodiment.

In addition, the separation membrane guides 125 can be located above and below the pair of upper nozzles 17. However, the position and number of the separation membrane guides 125 are not limited to this, and any position and number that can control the folding direction of the separation membrane sheet 122 is included in this embodiment.

Here, when the separation membrane guide 125 performs a linear reciprocating motion toward the first transfer device 141 and the second transfer device 142 based on the table 16, the separation membrane sheet 122 is folded along the movement direction of the separation membrane guide 125 so that the separation membrane sheet 122 can cover the electrode 11.

For example, referring to FIG. 5 and FIG. 6, when the first electrode 1112 is installed on the first region 1221 of the separation membrane sheet 122, the separation membrane guide 125 moves linearly toward the first conveying device 141 so that the second region 1222 of the separation membrane sheet 122 covers the top of the first electrode 1112.

Here, the first region 1221 of the separation membrane sheet 122 refers to the region in the separation membrane sheet 122 where the first electrode 1112 is attached. In some cases, the first region 1221 refers to the region in the separation membrane sheet 122 where the first electrode 1112 is attached while covering the second electrode 1122. The second region 1222 refers to the region in the separation membrane sheet 122 where the second electrode 1122 is attached while covering the first electrode 1112. In other words, the first electrode 1112 can be installed on the first region 1221 of the separation membrane sheet 122, and the second electrode 1122 can be installed on the second region 1222 of the separation membrane sheet 122.

In addition, the separation membrane guide 125 can move back and forth together with the pair of upper nozzles 17 with respect to the table 16, or the separation membrane guide 125 and the pair of upper nozzles 17 can each move back and forth.

That is, in this embodiment, when the first upper nozzle 171 applies the adhesive to at least a portion of the upper part of the first electrode 1112 as shown in FIG. 5 and FIG. 6, the separation membrane guide 125 moves linearly in the direction in which the separation membrane sheet 122 covers the first electrode 1112. Also, as described later in FIG. 7, when the second upper nozzle 172 applies the adhesive to at least a portion of the upper part of the second electrode 1122, the separation membrane guide 125 can move linearly in the direction in which the separation membrane sheet 122 covers the second electrode 1122.

This allows the separation membrane guide 125 to be Z-folded so that the separation membrane sheet 122 covers the upper and lower parts of the electrode 11.

More preferably, the separation membrane guide 125 and the pair of upper nozzles 17 can simultaneously reciprocate left and right based on the table 16. For example, as shown in Figures 5 and 6, when the first upper nozzle 171 applies adhesive from one side of the table 16 to the other side, the separation membrane guide 125 can also move linearly from one side of the table 16 to the other side to fold the separation membrane sheet 122.

As a result, the adhesive application process by the pair of upper nozzles 17 and the folding process of the separation membrane sheet 122 by the separation membrane guide 125 can be performed simultaneously, reducing the process time and improving the process efficiency.

Figure 7 is a schematic diagram showing how the second upper nozzle applies adhesive to the top of the second electrode while moving linearly in an electrode assembly manufacturing apparatus according to one embodiment of the present invention.

2, 6 and 7, in the electrode assembly manufacturing apparatus 1 according to this embodiment, similar to the first electrode 1112, the second electrode 1122 can be adsorbed to the second header 152 and can perform linear reciprocating motion. For example, as shown in FIG. 6, in a state in which the second electrode 1122 is adsorbed to the second header 152, the second header 152 can perform linear motion so as to be positioned above the table 16. At this time, the second electrode 1122 can be installed on the second region 1222 of the separator sheet 122. Other than that, the second electrode 1122 and the second header 152 can be described in the same manner as the first upper nozzle 171 described above.

Furthermore, similar to the first upper nozzle 171, the second upper nozzle 172 may perform a linear reciprocating motion based on the table 16. For example, the second upper nozzle 172 may apply adhesive to at least a portion of the upper surface of the second electrode 1122 as it moves from one side of the table 16 to the other. Otherwise, the second upper nozzle 172 may be described in the same manner as the first upper nozzle 171 described above.

Using such an electrode assembly manufacturing apparatus 1, an electrode assembly manufacturing method according to one embodiment of the present invention can be performed as follows.

First, referring to Figures 1 and 2, when the first electrode sheet 1111 is unwound from the first electrode reel 111, the first cutter 131 cuts the first electrode sheet 1111 to form a plurality of first electrodes 1112 (S101).

Meanwhile, when the separation membrane sheet 122 is unwound from the separation membrane reel 121, it is placed on the top surface of the table 16 (S102).

Then, the lower nozzle 173 applies adhesive to the lower part of the first electrode 1112 (S103). As an example, as shown in FIG. 3, the lower nozzle applies adhesive to the lower part of the first electrode 1112 while the first header 151 is adsorbing the first electrode 1112. As another example, as shown in FIG. 4, the lower nozzle 173 applies adhesive to the lower part of the first electrode 1112 while the first transport device 141 transports the first electrode 1112.

Referring also to FIG. 1 and FIG. 2, the first header 151 can move linearly above the table 16 while adsorbing the first electrode 1112. When the first header 151 is positioned above the table 16, as shown in FIG. 2, the first header 151 places the first electrode 1112 having the first adhesive layer 1710 formed thereon in the first region 1221 of the separation membrane sheet 122 (S104).

Referring again to FIG. 1 and FIG. 5, when the first electrode 1112 is installed in the first region 1221 of the separation membrane sheet 122, the first upper nozzle 171 can apply adhesive to the upper portion of the first electrode 1112 (S105). Here, the first upper nozzle 171 can form a second adhesive layer 1750 on the upper portion of the first electrode 1112 as it moves toward the first transfer device 141.

Referring again to FIG. 1 and FIG. 6, with at least a portion of the second adhesive layer 1750 formed on the top of the first electrode 1112, the separation membrane guide 125 moves in the same direction as the movement direction of the first upper nozzle 171, and one side of the separation membrane sheet 122 is folded so that the second region 1222 of the separation membrane sheet 122 covers the first electrode 1112 (S106).

Meanwhile, as shown in FIG. 2, when the second electrode sheet 1121 is unwound from the second electrode reel 112, the second cutter 132 cuts the second electrode sheet 1121. Then, a plurality of second electrodes 1122 are formed. When the second transport device 142 transports the second electrode 1122, the second header 152 adsorbs the second electrode 1122. Here, the first adhesive layer 1710 formed by applying adhesive from the lower nozzle 173 may be located on the lower part of the second electrode 1122 together with the first electrode 1112.

Also, as shown in FIG. 6, when the second region 1222 of the separation membrane sheet 122 covers the first electrode 1112, the second header 152 adsorbing the second electrode 1122 moves toward the top of the second region 1222 and places the second electrode 1122 on the top of the second region 1222.

Also, as shown in FIG. 7, the second upper nozzle 172 applies adhesive to the upper portion of the second electrode 1122. Here, as the second upper nozzle 172 moves toward the second transfer device 142, a second adhesive layer 1750 can be formed on the upper portion of the second electrode 1122.

Then, with at least a portion of the second adhesive layer 1750 formed on the top of the second electrode 1122, the separation membrane guide 125 moves in the same direction as the movement direction of the second upper nozzle 172, and the other side of the separation membrane sheet 122 is folded so that the first region 1221 of the separation membrane sheet 122 covers the second electrode 1122.

That is, by repeating the above process, the electrode assembly manufacturing method according to one embodiment of the present invention can be performed.

When performing the electrode assembly manufacturing method according to this embodiment of the present invention, when stacking the electrode 11 and the separator sheet 122 in a Z-folded manner, adhesive is applied to both the top and bottom of the electrode 11, preventing the electrode 11 from coming off from its designated position.

Figure 8 is a cross-sectional view of an electrode assembly according to one embodiment of the present invention.

Referring to FIG. 7 and FIG. 8, in an electrode assembly 10 in which electrodes and separator sheets according to another embodiment of the present invention are alternately stacked, the electrode 11 includes a first electrode 1112 and a second electrode 1122, and the separator sheet 122 has a zigzag shape formed by folding at least twice.

Here, the separation membrane sheet 122 is folded with the first electrode 1112 placed on the first region 1221 of the separation membrane sheet 122, and the second region 1222 of the separation membrane sheet 122 covers the first electrode 11. Also, the separation membrane sheet 122 is folded with the second electrode 1122 placed on the second region 1222 of the separation membrane sheet 122, and the first region 1221 of the separation membrane sheet 122 covers the second electrode 1122.

In particular, in the electrode assembly 10 according to this embodiment, the electrodes 11 may be stacked one by one on the first region 1221 or the second region 1222 of the separator sheet 122. In this case, the electrodes 11 may be stacked in accurate positions on the separator sheet 122 after measuring whether there is any misalignment and correcting their positions as necessary. As a result, the electrode assembly 10 according to this embodiment can further improve the alignment between the electrodes 11 and the separator sheet 122.

Here, an adhesive layer 1700 is formed between the electrode 11 and the separator sheet 122. More specifically, the adhesive layer 1700 includes a first adhesive layer 1710 and a second adhesive layer 1750. The first adhesive layer 1710 can be located between the lower part of the electrode 11 and the separator sheet 122, and the second adhesive layer 1750 can be located between the upper part of the electrode 11 and the separator sheet 122.

For example, the first adhesive layer 1710 and the second adhesive layer 1750 may each be formed by applying adhesive in the form of multiple dots. However, as previously described in the electrode assembly manufacturing apparatus 1, the form of the first adhesive layer 1710 and the second adhesive layer 1750 is not limited thereto, and may be formed in various forms.

As a result, in the electrode assembly 10 according to this embodiment, an adhesive layer 1700 is formed between the electrode 11 and the separator sheet 122, so that even in the case of a low-cost separator with excessively low adhesive strength, the electrode 11 and the separator can be stably fixed to each other, and the electrode 11 can be prevented from coming off from its fixed position. In addition, in the electrode assembly 10 according to this embodiment, one separator sheet 122 is folded to cover the upper and lower parts of the electrode 11, so that the alignment of the electrode 11 and the process efficiency can be further improved.

In addition, there is no need to perform a laminating process as in the past, which reduces the rate of defects in the process caused by high heat and pressure. Furthermore, since the laminator can be eliminated, the volume of the manufacturing equipment is reduced and the manufacturing process is simplified.

The separation membrane according to the embodiment described in this specification may be a CCS (ceramic coated separator). In general, a separation membrane is formed of a roll film and a coating layer formed on at least one surface of the roll film, and the coating layer may include alumina powder and a binder that holds the powder together. In a safety reinforced separator (SRS), a large amount of binder is coated on the surface of the coating layer, but in a CCS, the surface of the coating layer may not be coated with a binder or the content of the binder distributed on the surface may be much lower than that of an SRS. For example, in the case of a CCS separation membrane according to this embodiment, the content of the binder coated on the surface of the coating layer of the separation membrane may be about 3 wt% or less. For example, the content of the binder coated on the surface of the coating layer of the separation membrane may be about 2 wt% or less or about 1 wt% or less.

When the separator is CCS, the internal electrodes included in the electrode assembly are transported in an unfixed state, which may cause the alignment to become distorted during transport. Of course, when the separator is CCS, it can be fixed using heat and pressure, but the alignment of the internal electrodes may also become distorted during the process of transporting the electrode and separator laminate using a heat and pressure fixing device after the laminate is formed. Also, there is a disadvantage that an expensive separator with a high binder content must be used to attach the electrode and separator using heat and pressure. In contrast, according to this embodiment, the alignment of the internal electrodes can be prevented from becoming distorted during transport, while the fixing force can be increased.

Figure 9 is an exploded perspective view of a battery cell according to one embodiment of the present invention.

Referring to Figures 2, 8 and 9, a battery cell according to another embodiment of the present invention is a battery cell including the electrode assembly 10 described above, and includes a battery case 50 that houses the electrode assembly 10 together with an electrolyte, and the adhesive layer 1700 dissolves in the electrolyte.

Here, a fixing member such as a fixing tape 30 may be attached to the outside of the electrode assembly 10. This maintains the stacked alignment of the electrode 11 and the separator sheet 122. Such an electrode assembly 10 with the fixing tape 30 attached can be called the final electrode assembly 20.

The battery case 50 includes a storage section 60 in which the electrode assembly 10 or the final electrode assembly 20 is mounted, and a sealing section 70 that seals the outer periphery of the storage section 60. For example, the battery case 50 may be a laminate sheet including a resin layer and a metal layer. More specifically, the battery case 50 may be made of a laminate sheet and may be composed of an outer resin layer forming the outermost shell, a barrier metal layer that prevents penetration of materials, and an inner resin layer for sealing.

The storage portion 60 of the battery case 50 may also receive an electrolyte together with the electrode assembly 10. Here, the adhesive layer 1700 included in the electrode assembly 10 may dissolve in the electrolyte. In particular, in the battery cell according to this embodiment, the adhesive layer 1700 included in the electrode assembly 10 may dissolve in the electrolyte under high temperature and/or pressure conditions during an activation process such as a formation process.

More specifically, in the battery cell according to this embodiment, when the adhesive layer 1700 formed between the electrode 11 of the electrode assembly 10 and the separator sheet 122 dissolves in the electrolyte, there may be little or no adhesive 14 remaining on the surface of the electrode 11.

In contrast, the separation membrane sheet 122 is generally a porous sheet, and therefore some of the adhesive 14 may have permeated into the separation membrane sheet 122. However, even in the case of the adhesive layer 1700 having permeated into the separation membrane sheet 122, it may be largely or completely dissolved in the electrolyte, and during this process, traces of the adhesive layer 1700 application may remain on the separation membrane sheet 122.

Here, the application trace of the adhesive layer 1700 means that the adhesive component contained in the adhesive layer 1700 does not remain, but a part of the outer surface of the separation membrane sheet 122 is deformed by the adhesive layer 1700. However, it is not limited thereto, and the application trace of the adhesive layer 1700 can mean a trace that can confirm the presence or absence of adhesive application in various ways, such as a trace that can confirm the presence or absence of adhesive application with the naked eye. Thus, the application trace of the adhesive layer 1700 formed on the separation membrane sheet 122 can be formed in the same position as the position where the adhesive is applied.

As a result, in the battery cell according to this embodiment, the adhesive layer 1700 dissolves completely on the surface of the electrode 11 or the separation membrane 122, and the unreacted areas of the adhesive layer 1700 disappear, preventing a decrease in performance and achieving excellent battery performance.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

1: Electrode assembly manufacturing apparatus 11: Electrode 16: Table 17: Nozzle 111: First electrode reel 112: Second electrode reel 121: Separation membrane reel 122: Separation membrane sheet 125: Separation membrane guide 131: First cutter 132: Second cutter 141: First transfer device 142: Second transfer device 151: First header 152: Second header 171: First upper nozzle 172: Second upper nozzle 1111: First electrode sheet 1112: First electrode 1121: Second electrode sheet 1122: Second electrode 1221: First region 1222: Second region 1710: First adhesive layer 1750: Second adhesive layer

Claims (19)

an electrode supply unit provided with an electrode sheet on which a plurality of electrodes are formed;
a separation membrane supply unit for providing a separation membrane sheet that is folded when the electrodes are installed, covers the electrodes, and is laminated with the electrodes;
a table upon which the electrodes are placed with the separator sheet folded between the electrodes to form an electrode assembly;
A separator guide for guiding a folding direction of the separator sheet; and a pair of upper applicators for applying adhesive to at least a part of the upper part of the electrode installed on the table,
The separation membrane guide and the pair of upper coaters are linearly reciprocated left and right based on the table,
The table is fixed, an electrode assembly manufacturing apparatus. The electrode supply unit includes:
2. The electrode assembly manufacturing apparatus of claim 1, comprising: a first electrode reel from which a first electrode sheet on which a plurality of first electrodes are formed is unwound; and a second electrode reel from which a second electrode sheet on which a plurality of second electrodes are formed is unwound. The pair of top coaters includes a first top nozzle and a second top nozzle,
the first upper nozzle applies the adhesive to an upper portion of the first electrode;
The electrode assembly manufacturing apparatus of claim 2 , wherein the second upper nozzle applies the adhesive to an upper portion of the second electrode. The electrode assembly manufacturing apparatus of claim 3, wherein the first upper nozzle and the second upper nozzle are disposed on either side of the separation membrane guide. The first electrode is disposed on a first region of the separation membrane sheet,
The electrode assembly manufacturing apparatus according to claim 3 , wherein the second electrode is disposed on a second region of the separator sheet. When the first electrode is placed on the first region of the separation membrane sheet, the first upper nozzle moves linearly on the first electrode,
The electrode assembly manufacturing apparatus according to claim 5 , wherein when the second electrode is placed on the second region of the separator sheet, the second upper nozzle moves linearly above the second electrode. When the first upper nozzle applies the adhesive to at least a portion of the upper surface of the first electrode, the separation membrane guide moves linearly in a direction in which the separation membrane sheet covers the first electrode,
7. The electrode assembly manufacturing apparatus of claim 6, wherein when the second upper nozzle applies the adhesive to at least a portion of the upper surface of the second electrode, the separator guide moves linearly in a direction in which the separator sheet covers the second electrode. The electrode assembly manufacturing apparatus according to claim 5, further comprising a lower applicator that applies the adhesive to the lower part of the first electrode and the lower part of the second electrode, respectively. The electrode assembly manufacturing apparatus of claim 8 , further comprising: a first header that adsorbs and places the first electrode in the first region; and a second header that adsorbs and places the second electrode in the second region. When the first electrode is attached to the first header, the lower coater coats the adhesive on a lower portion of the first electrode,
The electrode assembly manufacturing apparatus of claim 9 , wherein when the second electrode is attracted to the second header, the lower coater coats the adhesive on a lower portion of the second electrode. 9. The electrode assembly manufacturing apparatus of claim 8, further comprising: a first transfer device for transferring the first electrode toward the table; and a second transfer device for transferring the second electrode toward the table. the first transfer device includes a first groove that is open toward the first electrode, and the lower applicator applies the adhesive to a lower portion of the first electrode through the first groove;
12. The electrode assembly manufacturing apparatus of claim 11, wherein the second transfer device includes a second groove that is open toward the second electrode, and the lower coater applies the adhesive to the lower portion of the second electrode through the second groove. cutting the first electrode sheet unwound from the first electrode supply unit to form a plurality of first electrodes;
a step of placing a separation membrane sheet provided from a separation membrane supply unit on a table along a separation membrane guide;
applying an adhesive to a lower portion of the first electrode by a lower coater;
placing the first electrode in a first region of the separator sheet;
applying an adhesive to an upper portion of the first electrode by a first upper nozzle; and folding the separator sheet in a folding direction guided by the separator guide so that a second region of the separator sheet covers the first electrode. After covering the top of the first electrode,
cutting the second electrode sheet provided by the second electrode supply unit to form a plurality of second electrodes;
applying an adhesive to a lower portion of the second electrode by a lower coater;
placing the second electrode in the second region of the separator sheet;
14. The method of claim 13, further comprising: applying adhesive to an upper portion of the second electrode by a second upper nozzle; and folding the separator sheet in a folding direction guided by the separator guide so that the first region of the separator sheet covers the second electrode. The table is fixed,
The method of claim 14 , wherein the separation membrane guide, the first upper nozzle, and the second upper nozzle linearly reciprocate with respect to the table. An electrode assembly in which electrodes and separator sheets are alternately stacked,
the electrodes include a first electrode and a second electrode;
The separation membrane sheet has a zigzag shape formed by folding at least twice,
The separation membrane sheet is folded with the first electrode disposed on the first region of the separation membrane sheet, and the second region of the separation membrane sheet covers the first electrode, and the separation membrane sheet is folded with the second electrode disposed on the second region, and the first region of the separation membrane sheet covers the second electrode,
An adhesive layer is formed between the electrode and the separation membrane sheet,
The electrode assembly, wherein the adhesive layer is soluble in an electrolyte for use in a battery cell. the adhesive layer includes a first adhesive layer and a second adhesive layer;
The first adhesive layer is located between the lower part of the electrode and the separator sheet,
17. The electrode assembly of claim 16, wherein the second adhesive layer is located between a top of the electrode and the separator sheet. The electrode assembly according to claim 17, wherein the first adhesive layer and the second adhesive layer are each formed by applying adhesive in the form of a plurality of dots. A battery cell including the electrode assembly of claim 16,
a battery case that houses the electrode assembly together with an electrolyte;
The adhesive layer dissolves in the electrolyte.

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