Electrode assembly wrapping device, wrapping method, and electrode assembly manufactured thereby

Abstract

In one example, the disclosed electrode assembly wrapping device includes a lower stage that is equipped with a plurality of sealing bars on its upper surface and is movable up and down, a pair of side sealing blocks that are arranged on both sides of the lower stage and are movable toward and away from the lower stage, and an upper stage that is arranged above the lower stage, is equipped with a plurality of sealing bars on its bottom surface and is movable up and down relative to the lower stage.

Description

[Technical Field]

[0001] The present invention relates to an electrode assembly wrapping device and wrapping method for wrapping a film around the surface of an electrode assembly in which a plurality of battery cells are stacked, to secure the battery cells so that they are not separated or misaligned, and to an electrode assembly manufactured thereby.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0063887, filed May 17, 2023, and Korean Patent Application No. 10-2024-0063046, filed May 14, 2024, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and have the potential to be small and have large capacities, and as such, they have been the subject of much research and development in recent years. Demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to modern demands for environmental protection.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. The electrode assembly installed inside the battery case of a secondary battery is a power generating element that can be charged and discharged and is made up of a laminated structure of electrodes and a separator.

[0005] Electrode assemblies can be broadly classified into a jellyroll type in which a sheet-like positive electrode and negative electrode coated with an active material are wound up with a separator interposed between them; a stack type in which multiple positive electrodes and negative electrodes are stacked in sequence with a separator interposed between them; and a stack and folding type in which stack-type unit cells are wound up with a long separator film.

[0006] A stacked electrode assembly is made by stacking multiple battery cells (bi-cells or mono-cells with a separator between the positive and negative electrodes), and each battery cell must be fixed in place to maintain accurate alignment. To achieve this, a taping process was performed in which several strips of adhesive tape were wrapped around the surface of the electrode assembly.

[0007] However, while the taping process of wrapping the edges of the electrode assembly with adhesive tape is effective in bundling multiple stacked battery cells together, it is not sufficient to prevent bending of the electrode assembly impregnated with electrolyte or swelling during use. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide an electrode assembly wrapping device and wrapping method that can firmly secure each battery cell of an electrode assembly, in which a plurality of battery cells are stacked, to each other, thereby suppressing bending of the electrode assembly impregnated with an electrolyte and swelling during use.

[0009] Another object of the present invention is to provide an electrode assembly wrapping device and wrapping method that can solve the problem of wrinkles occurring on the surface of a film or damage to battery cells during a wrapping process for ensuring cell fixation of an electrode assembly.

[0010] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0011] The present invention relates to an electrode assembly wrapping device, and in one example, includes a lower stage that is equipped with a plurality of sealing bars on its upper surface and is movable up and down, a pair of side sealing blocks that are arranged on both sides of the lower stage and are movable toward and away from the lower stage, and an upper stage that is arranged above the lower stage, is equipped with a plurality of sealing bars on its bottom surface and is movable up and down relative to the lower stage.

[0012] In one embodiment of the present invention, the side sealing block may have an intake hole formed on the sealing surface.

[0013] The spacing between the plurality of sealing bars provided on the lower stage and the upper stage may be adjustable.

[0014] A film stage and / or a cell stage may be provided outside the pair of side sealing blocks based on the lower stage.

[0015] The film stage and the cell stage may include a film magazine and a cell magazine, respectively, in which a plurality of films and electrode assemblies are stacked and accommodated.

[0016] The upper stage is mounted on an XY stage arranged along an XY plane parallel to the sealing surface of the lower stage, thereby allowing the upper stage to move relative to the lower stage in three dimensions.

[0017] The upper stage may include a carrier for holding the film and electrode assemblies stacked in the film magazine and cell magazine, respectively, and moving the film and electrode assemblies onto the lower stage.

[0018] Meanwhile, the present invention provides a wrapping method for an electrode assembly, comprising the steps of placing a cut first film on a plurality of sealing bars provided on an upper surface of a lower stage, aligning and placing an electrode assembly on the first film, lowering the upper stage so that a plurality of sealing bars provided on a bottom surface of the upper stage come into contact with the electrode assembly, and, as the lower and upper stages are lowered in a state of being in close contact with the electrode assembly, a pair of side sealing blocks press the first film protruding from the sides of the sealing bars against the side surfaces of the electrode assembly, and operating the sealing bars and side sealing blocks of the lower stage to attach the first film to the bottom and side surfaces of the electrode assembly. and placing the cut second film on the upper surface of the electrode assembly in an aligned manner while the upper stage is separated from the lower stage. The upper stage is lowered so that a plurality of sealing bars provided on the upper stage contact the second film. The lower and upper stages are in close contact with the electrode assembly, and the entire lower and upper stages are lowered below the side sealing blocks and then raised, causing the side sealing blocks to tightly seal the second film protruding from the sides of the sealing bars to the sides of the electrode assembly, and in this process, the sealing bars and side sealing blocks of the upper stage are operated to attach the second film to the upper and side surfaces of the electrode assembly.

[0019] The pair of side sealing blocks are disposed on both sides of the lower stage so as to be movable toward and away from the lower stage, and can be moved toward the lower stage to attach the first and second films to the sides of the electrode assembly.

[0020] The pair of side sealing blocks may apply negative pressure to the first and second films while attaching them to the side surfaces of the electrode assembly, thereby preventing wrinkles from occurring.

[0021] The spacing between the sealing bars provided on the lower and upper stages can be adjusted to correspond to the width of the electrode assembly.

[0022] In some embodiments of the present invention, the electrode assembly and the first and second films may be stacked and housed in a film magazine and a cell magazine, respectively, and may be held by a carrier one by one and moved onto the lower stage.

[0023] The first and second films include adhesive layers that are activated by heat, and after wrapping on the bottom, top, and side surfaces of the electrode assembly is completed, the first and second films are heated, so that the first and second films can be adhered to the electrode assembly.

[0024] In one embodiment, the adhesive layer is an EVA (Ethylene-Vinyl Acetate) layer, and the adhesive action of the EVA layer can be activated in a temperature range of 140±20°C.

[0025] The wrapping method of the present invention, which includes the above-described series of steps, provides an electrode assembly including a plurality of stacked battery cells, a first film attached to the bottom and both side surfaces of the electrode assembly, and a second film attached to the top and both side surfaces of the electrode assembly.

[0026] Here, the second film may be attached to both sides of the electrode assembly so as to overlap the first film.

[0027] For example, the first and second films may be PET (PolyEthyleneTerephthalate) films.

[0028] An adhesive layer may be interposed between the first and second films and the electrode assembly.

[0029] For example, the adhesive layer may be an EVA layer, and the EVA layer may be heat-activated to have adhesive properties.

[0030] The first and second films may encase the bottom, top and both side surfaces of the electrode assembly so as not to expose them.

[0031] The first and second films may apply a compressive force across the bottom, top and both side surfaces of the electrode assembly. [Effects of the Invention]

[0032] According to the electrode assembly wrapping apparatus and wrapping method of the present invention having the above-described configuration, a film can be accurately attached to the surface of the electrode assembly by using a lower stage and an upper stage each equipped with a plurality of sealing bars and a pair of side sealing blocks.

[0033] In addition, the side of the film can be attached by applying negative pressure through the suction holes provided in the side sealing blocks, which effectively prevents wrinkles from occurring on the surface of the film attached in a small area.

[0034] Furthermore, the electrode assembly manufactured using the electrode assembly wrapping device and wrapping method of the present invention exhibits strong resistance to bending and swelling of the electrode assembly because the stacked battery cells are firmly fixed to each other with the wrapping film.

[0035] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0036] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a view showing the outer appearance of a wrapping device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the main configuration of the wrapping device. [Figure 3] 1 is a perspective view of the wrapping device as seen from a different direction. [Figure 4] FIG. [Figure 5] 1 is a diagram showing a series of steps for attaching a film to the surface of an electrode assembly using a wrapping device of the present invention. [Figure 6] 1 is a diagram showing a series of steps for attaching a film to the surface of an electrode assembly using a wrapping device of the present invention. [Figure 7] 1 is a diagram showing a series of steps for attaching a film to the surface of an electrode assembly using a wrapping device of the present invention. [Figure 8] 1 is a diagram showing a series of steps for attaching a film to the surface of an electrode assembly using a wrapping device of the present invention. [Figure 9] 1 is a diagram showing a series of steps for attaching a film to the surface of an electrode assembly using a wrapping device of the present invention. [Figure 10] 1 is a diagram showing a series of steps for attaching a film to the surface of an electrode assembly using a wrapping device of the present invention. [Figure 11] 1 is a view showing an example of an electrode assembly completed by the wrapping method of the present invention. [Figure 12] 10 is a view showing another example of an electrode assembly completed by the wrapping method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] Because the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0039] However, this is not intended to limit the invention to any particular embodiment, but rather to be understood as including all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0040] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0041] Furthermore, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion therebetween. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion therebetween. Furthermore, in this application, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0042] The present invention relates to an electrode assembly wrapping device, and in one example, includes a lower stage that is equipped with a plurality of sealing bars on its upper surface and is movable up and down, a pair of side sealing blocks that are arranged on both sides of the lower stage and are movable toward and away from the lower stage, and an upper stage that is arranged above the lower stage, is equipped with a plurality of sealing bars on its bottom surface and is movable up and down relative to the lower stage.

[0043] In one embodiment of the present invention, the side sealing block may have an intake hole formed on the sealing surface.

[0044] Using the electrode assembly wrapping device having the above configuration, it is possible to accurately attach a film to the surface of the electrode assembly by using a lower stage and an upper stage each equipped with a plurality of sealing bars and a pair of side sealing blocks.

[0045] In addition, the side of the film can be attached by applying negative pressure through the suction holes provided in the side sealing block, which prevents wrinkles from occurring on the surface of the film attached in a small area.

[0046] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0047] (First embodiment) 1 is a diagram showing the exterior of an electrode assembly wrapping apparatus 10 (hereinafter simply referred to as the "wrapping apparatus") according to one embodiment of the present invention. In the wrapping apparatus 10 of FIG. 1, as one example, major tools and components are installed within the space inside a cabinet 12, and the enclosed structure of the cabinet 12 protects the major components inside from various foreign substances such as dust. The major components are fixed and supported by frames 14 installed vertically and horizontally inside the cabinet 12, and various doors are provided through which electrode assemblies 520 and films 420 can be added or maintenance such as inspection and repair can be performed.

[0048] 2 and 3 are perspective views showing the main components of the wrapping apparatus 10 installed in the cabinet 12, and Fig. 4 is a front view of the wrapping apparatus. The illustrated wrapping apparatus 10 mainly includes a lower stage 100, a pair of side sealing blocks 200, and an upper stage 300.

[0049] The lower stage 100 has a plurality of sealing bars 110 on its upper surface, which can move up and down along the Z-axis direction (height direction) in the drawing. The sealing bars 110 are components that generate and supply heat necessary to attach the film 420 to the surface of the electrode assembly 520.

[0050] A pair of side sealing blocks 200 are disposed on both sides of the lower stage 100. The side sealing blocks 200 are sealing devices for attaching the film 420 to both sides of the electrode assembly 520, and the heating temperature of the sealing surface 210 corresponds to the heating temperature of the sealing bar 110 of the lower stage 100. Each of the pair of side sealing blocks 200 is movable toward and away from the lower stage 100. The movement of the side sealing blocks 200 is linked to the vertical movement of the lower stage 100 and the upper stage 300, which will be described later. This linked vertical movement and movement allows the film 420 to be attached to the top, bottom, and both sides of the electrode assembly 520.

[0051] The upper stage 300 is disposed above the lower stage 100, and a sealing bar 310 corresponding to the sealing bar 110 of the lower stage 100 is provided on the bottom surface of the upper stage 300. The sealing bar of the upper stage 300 is also heated to a temperature corresponding to the heating temperature of the sealing bar 110 of the lower stage 100. The upper stage 300 can be raised and lowered relative to the lower stage 100, and during the lapping process, the lower stage 100 and the upper stage 300 apply a suitable sealing pressure while fixing the electrode assembly 520 located therebetween.

[0052] The lower stage 100 and the upper stage 300 can be raised and lowered using a conventional cylinder device. While the cylinder device can be electrically operated, hydraulically operated, or pneumatically operated, it is preferable that the lower stage 100 and the upper stage 300 be raised and lowered using pneumatic means, since the suction holes 220 of the side sealing blocks 200 (described below) use pneumatic pressure. The sealing pressure of the pneumatically operated lower stage 100 and upper stage 300 corresponds to pneumatic pressure, and the sealing pressure may be in the range of approximately 3±0.2 bar. For the same reason, the pair of side sealing blocks 200 can also be moved back and forth using pneumatic means.

[0053] 2, a partial enlargement of the side sealing block 200 shows that a plurality of suction holes 220 are formed on the sealing surface 210 of the side sealing block 200. During the wrapping operation of the wrapping device 10, the side sealing block 200 enters the lower stage 100 and attaches the film 420 to the narrow side of the electrode assembly 520. Attaching the edge of the film 420 to a narrow area can easily cause wrinkles in the film 420 during the attachment process. Wrinkles in the film 420 during the wrapping process can cause defects and must be prevented. To this end, the present invention provides a plurality of suction holes 220 on the sealing surface 210 of the side sealing block 200. In other words, the side sealing block 200 attracts the film 420 with negative pressure generated by the suction holes 220, maintaining a tensioned state while attaching the film 420. This prevents wrinkles from occurring when attaching the edge of the film 420 to the side of the electrode assembly 520.

[0054] 2 to 4, the lower stage 100 and the upper stage 300 each include three sealing bars 110, 310, respectively. According to one embodiment of the present invention, when a plurality of sealing bars 110, 310 are provided, the spacing between the sealing bars 110, 310 may be adjustable. For example, in a three-sealing bar system, the sealing bars on both sides may move linearly around the central sealing bar, thereby changing the area occupied by the entire sealing bars 110, 310. The area formed by the plurality of sealing bars 110, 310 corresponds to the width of the electrode assembly 520. In other words, adjusting the spacing between the plurality of sealing bars 110, 310 enables wrapping of electrode assemblies 520 with various widths. Of course, adjusting the spacing between the sealing bars 110, 310 also adjusts the distance the pair of side sealing blocks 200 move back and forth.

[0055] Meanwhile, in order to efficiently perform the wrapping process performed sequentially on the plurality of electrode assemblies 520, a film stage 400 and / or a cell stage 500 may be provided outside the pair of side sealing blocks 200 relative to the lower stage 100. The film stage 400 and the cell stage 500 include a film magazine 410 and a cell magazine 510, respectively, in which a plurality of films 420 and electrode assemblies 520 are stacked and accommodated.

[0056] Furthermore, the upper stage 300 is mounted on an XY stage 600 arranged along an XY plane parallel to the sealing surface 210 of the lower stage 100, so that the upper stage 300 can be configured to be movable three-dimensionally relative to the lower stage 100. The XY stage 600 is fixedly installed on a frame 14 installed within the cabinet 12, and the upper stage 300 suspended by the XY stage 600 can be moved to any position on the XY plane. Furthermore, as described above, the upper stage 300 can be moved up and down relative to the lower stage 100, so that the upper stage 300 can move three-dimensionally in the XYZ space relative to the lower stage 100.

[0057] The upper stage 300, which is capable of three-dimensional movement, may be provided with a carrier 700 corresponding to the installation of the film stage 400 and / or cell stage 500. The carrier 700 serves to hold the films 420 and electrode assemblies 520 stacked and accommodated in the film magazine 410 and the cell magazine 510, respectively, and move them onto the lower stage 100. The configuration of the carrier 700 and the film stage 400 and / or cell stage 500 allows the wrapping process for a large number of electrode assemblies 520 to be automated and efficiently performed.

[0058] Heating elements, such as electric heating wires, may be built into the sealing bars 110 of the lower stage 100, the sealing bars 310 of the upper stage 300, and the sealing surfaces 210 of the side sealing blocks 200. The heating elements built into the sealing bars 110, 310 of the lower stage 100 and the upper stage 300 and the sealing surfaces 210 of the side sealing blocks 200 may be provided for the purpose of activating the adhesive action of the adhesive layer 430 (see FIG. 12) provided on the surface of the film 420.

[0059] When wrapping the top, bottom, and both sides of the electrode assembly 520 with the film 420, if the adhesive layer 430 on the surface of the film 420 is sticky, wrapping becomes difficult and the risk of defects increases. Therefore, it is preferable to form the adhesive layer 430 on the attachment surface of the film 420 using a material that remains non-sticky and smooth at room temperature but whose adhesive function is activated only when heated to a certain temperature. Specific details regarding this will be described in detail in the following second embodiment.

[0060] (Second embodiment) 1 to 4, the configuration of the wrapping device 10 was described in detail in the first embodiment. Subsequently, in the second embodiment, a wrapping method for an electrode assembly (hereinafter simply referred to as the "wrapping method") will be described, in which a film 420 is attached to the surface of an electrode assembly 520 using the above-mentioned wrapping device 10. FIGS. 5 to 10 are diagrams showing a series of steps for attaching a film 420 to the surface of an electrode assembly 520 using the wrapping device 10 of the present invention. The wrapping method for an electrode assembly 520 according to the present invention can be clearly understood through the accompanying drawings and description.

[0061] 5 shows a step of placing a first film 421 cut to the size of the electrode assembly 520 on a plurality of sealing bars 110 provided on the upper surface of the lower stage 100, and a step of aligning and placing the electrode assembly 520 on the first film 421. In the step of FIG. 5, the lower stage 100 is raised to a position suitable for placing the first film 421 and the electrode assembly 520, and the pair of side sealing blocks 200 are retracted.

[0062] 6 shows the next step, in which the upper stage 300 descends so that the plurality of sealing bars 310 provided on the bottom surface of the upper stage 300 come into contact with the electrode assembly 520 placed on the sealing bar 110 of the lower stage 100. Therefore, in the step of FIG. 6, the sealing bar 310 of the upper stage 300, the electrode assembly 520, the first film 421, and the sealing bar 110 of the lower stage are positioned in this order from the top, and the upper stage 300 and the lower stage press and fix the electrode assembly 520 and the first film 421 with a pressure suitable for adhering the first film 421, for example, a pressure in the range of 3±0.2 bar.

[0063] 6 and 7, when the lower stage 100 and the upper stage 300 are in close contact with the electrode assembly 520, the pair of side sealing blocks 200 advance at a suitable time so that their sealing surfaces 210 are positioned corresponding to the sides of the electrode assembly 520. At this time, the sealing surfaces 210 of the side sealing blocks 200 are positioned below the first film 421 and the electrode assembly 520. When the lower stage 100 and the upper stage 300 are lowered in this state, the pair of side sealing blocks 200 bring the first film 421 protruding from the sides of the sealing bars 110, 310 into close contact with the sides of the electrode assembly 520. In this state, the sealing bar 110 of the lower stage 100 and the side sealing blocks 200 are activated and heated, so that the first film 421 is attached to the bottom and sides of the electrode assembly 520.

[0064] After the attachment of the first film 421 is completed, the next step is to attach the second film 422. As shown in Fig. 8, in order to place the second film 422 on the upper surface of the electrode assembly 520, the upper stage is raised and separated from the lower stage 100, and the identically cut second film 422 is aligned and placed on the exposed upper surface of the electrode assembly 520.

[0065] 9, similar to FIG. 6 described above, shows a state in which the upper stage 300 has descended so that the sealing bars 310 provided on the upper stage 300 contact the second film 422. Unlike the case of FIG. 6 for attaching the first film 421, the second film 422 is positioned below the sealing surface 210 of the side sealing block 200. This is because the second film 422 is placed on the upper surface of the electrode assembly 520, and therefore the force attaching the end of the second film 422 to the side of the electrode assembly 520 must act in the opposite manner to that in FIG. 6. Therefore, the pair of side sealing blocks 200 must advance only after the entire lower stage 100 and upper stage 300 have descended and the second film 422 is positioned below the sealing surface 210.

[0066] FIG. 10 shows the final process of attaching the second film 422. With the lower stage 100 and upper stage 300 tightly adhering the electrode assembly 520 to each other, the entire assembly rises from below the sealing surface 210 of the side sealing block 200. As a result, the side sealing block 200 presses the second film 422, which protrudes from the sides of the sealing bars 110 and 310, against the side of the electrode assembly 520. During this process, the sealing bar 310 of the upper stage 300 and the side sealing block 200 are heated to attach the second film 422 to the top and sides of the electrode assembly 520.

[0067] In the wrapping method including this series of steps, various configurations of the wrapping apparatus 10 described in the first embodiment may be utilized. For example, the pair of side sealing blocks 200 may apply negative pressure to adhere the first film 421 and the second film 422 to the sealing surface 210 while adhering them to the side surfaces of the electrode assembly 520, thereby preventing wrinkles from occurring. In addition, the spacing between the plurality of sealing bars 110, 310 provided on the lower stage 100 and the upper stage 300 may be adjusted to correspond to the width of the electrode assembly 520, and the films 420 and the electrode assemblies 520 stacked and accommodated in the film magazine 410 and the cell magazine 510, respectively, may be held one by one by the carrier 700 and moved onto the lower stage 100.

[0068] 11 is a diagram showing an example of an electrode assembly 520 completed by the wrapping method of the present invention described with reference to FIGS. 5 to 10. The illustrated electrode assembly 520 refers to an electrode assembly 520 to which a film 420 is attached, i.e., an electrode assembly 520 after the wrapping process, and includes an electrode assembly 520 in which a plurality of battery cells are stacked, a first film 421 attached to the bottom and both sides of the electrode assembly 520, and a second film 422 attached to the top and both sides of the electrode assembly 520. The first film 421 and the second film 422 may be thin films 420 made of a material that has excellent strength (tensile strength, burst strength, etc.), for example, a PET (Polyethylene Terephthalate) film.

[0069] 11, the electrode assembly 520 has a structure in which the second film 422 covering the upper surface of the electrode assembly 520 is overlapped and attached onto the first film 421. It can be clearly understood that this overlapping structure of the films 421 and 422 on both sides of the electrode assembly 520 is due to the wrapping method described above.

[0070] 12 shows another example of an electrode assembly 520 completed by the wrapping method of the present invention. The basic attachment structure of the electrode assembly 520 and the film 420 is the same, but there are some differences in the structure. The characteristic structure of the electrode assembly 520 of FIG. 12 will be explained as follows.

[0071] The first film 421 and the second film 422 include a heat-activated adhesive layer 430. The adhesive layer 430 is formed on the surface (attachment surface) of the first film 421 and the second film 422 that is attached to the electrode assembly 520. The adhesive layer 430 is preferably made of a material that maintains a smooth, non-sticky surface at room temperature but whose adhesive function is activated only when heated to a certain temperature. For example, the adhesive layer may be an EVA (Ethylene-Vinyl Acetate) layer, and the adhesive function of the EVA layer may be activated in a temperature range of 140±20°C. Due to the physical properties of the adhesive layer 430, the film 420 can be attached evenly and smoothly to the surface of the electrode assembly 520 without defects such as wrinkles or bubbles, as described above.

[0072] It is preferable to activate the adhesive function of the adhesive layer 430, such as an EVA layer, provided on the film 420 after wrapping the bottom, top, and sides of the electrode assembly 520, in order to prevent defects such as wrinkles. Therefore, in the wrapping method according to the present invention, when the film 420 having the heat-activated adhesive layer 430 is used, heating elements built into the sealing bars 110 and 310 of the lower stage 100 and the upper stage 300 and the sealing surface 210 of the side sealing block 200 may be activated as a step after wrapping the bottom, top, and both sides of the electrode assembly 520 with the first film 421 and the second film 422. The adhesive function of the adhesive layer 430 is activated by heating, so that the wrapping process of the film 420 on the electrode assembly 520 is completed more firmly.

[0073] 12, the first film 421 and the second film 422 may be attached to the electrode assembly 520 over a wide area that does not expose the bottom, top, and both side surfaces of the electrode assembly 520. In other words, the first film 421 and the second film 422 may be attached across the entire width of the electrode assembly 520. In practice, taking into consideration alignment errors that may occur between the first film 421 and the second film 422 and the electrode assembly 520 on the wrapping device 10, the widths of the first film 421 and the second film 422 may be greater than the overall width of the electrode assembly 520, for example, a width length corresponding to approximately 105 to 110% of the overall width of the electrode assembly 520.

[0074] The first film 421 and the second film 422 are tightly attached to the bottom, top, and both side surfaces of the electrode assembly 520, thereby applying a uniform compressive force around the electrode assembly 520. The compressive force of the film 420 can be further strengthened with the aid of the adhesive layer 430. Conventional taping processes that wrap the electrode assembly 520 with adhesive tape apply a localized fixing force to the electrode assembly 520, resulting in insufficient and uneven fixing force. In contrast, the electrode assembly 520 manufactured using the wrapping device 10 and wrapping method of the present invention applies a uniform fixing force of the film 420 across a wide area across the entire width. This allows the stacked battery cells to be firmly fixed to each other by the wrapped film. As a result, the electrode assembly 520 exhibits strong resistance to bending and swelling.

[0075] In particular, the electrode assembly 520 manufactured using the wrapping apparatus 10 and wrapping method of the present invention can stably secure multiple battery cells to each other without defects such as wrinkles or bubbles occurring in the film 420 during the wrapping process due to the film 420 being attached across the entire width and the pair of side sealing blocks 200 that apply negative pressure while attaching the first film 421 and the second film 422 to the sides of the electrode assembly 520. Furthermore, with the help of the adhesive layer 430 that is activated by heat, the fixing force of the film 420 to the electrode assembly 520 can be stably maintained for a long period of time, thereby improving the stability of the electrode assembly 520.

[0076] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0077] 10: Wrapping device 12: Cabinet 14: Frame 100: Lower Stage 110: Ceiling bar 200: Side sealing block 210: Sealing surface 220: Intake hole 300: Upper Stage 310: Ceiling bar 400: Film Stage 410: Film Magazine 420:Film 421: First Film 422: Second Film 430: Adhesive layer 500: Cell Stage 510: Cell Magazine 520: Electrode assembly 600:XY Stage 700: Career

Claims

1. A lower stage with multiple sealing bars on the top surface and movable up and down. a pair of side sealing blocks disposed on both sides of the lower stage and movable toward and away from the lower stage; The electrode assembly wrapping device includes an upper stage disposed above the lower stage, the upper stage having a plurality of sealing bars on a bottom surface thereof, and being movable up and down relative to the lower stage.

2. The side sealing block is 2. The electrode assembly wrapping device according to claim 1, wherein an intake hole is formed on the sealing surface.

3. 2. The electrode assembly wrapping apparatus of claim 1, wherein the spacing between the sealing bars provided on the lower stage and the upper stage is adjustable.

4. On the outside of the pair of side sealing blocks based on the lower stage, The electrode assembly wrapping apparatus according to claim 1 , further comprising a film stage and / or a cell stage.

5. 5. The electrode assembly wrapping device according to claim 4, wherein the film stage and the cell stage comprise a film magazine and a cell magazine, respectively, in which a plurality of films and electrode assemblies are stacked and housed.

6. the upper stage is mounted on an XY stage arranged along an XY plane parallel to a sealing surface of the lower stage; 6. The electrode assembly lapping apparatus according to claim 5, wherein the upper stage is movable relative to the lower stage in three dimensions.

7. The upper stage is 7. The electrode assembly wrapping device according to claim 6, further comprising a carrier for holding the films and the electrode assemblies stacked in the film magazine and the cell magazine, respectively, and moving the films and the electrode assemblies onto the lower stage.

8. placing the cut first film on a plurality of sealing bars provided on the upper surface of the lower stage; placing an electrode assembly on the first film in an aligned manner; lowering the upper stage so that a plurality of sealing bars provided on a bottom surface of the upper stage come into contact with the electrode assembly; a pair of side sealing blocks pressing the first film protruding from the side of the sealing bar against the side of the electrode assembly while the lower stage and the upper stage are in close contact with the electrode assembly and then operating the sealing bar and the side sealing blocks of the lower stage to attach the first film to the bottom and side of the electrode assembly; placing the cut second film on the upper surface of the electrode assembly in an aligned manner while the upper stage is separated from the lower stage; the upper stage descending so that a plurality of sealing bars provided on the upper stage contact the second film; and the lower stage and the upper stage being in close contact with the electrode assembly, the entire lower stage being lowered below the side sealing blocks and then being raised, causing the side sealing blocks to tightly seal the second film protruding from the sides of the sealing bars to the sides of the electrode assembly, and operating the sealing bars and the side sealing blocks of the upper stage to attach the second film to the top and side surfaces of the electrode assembly.

9. The pair of side sealing blocks are 9. The wrapping method of claim 8, wherein the first and second films are disposed on both sides of the lower stage so as to be movable toward and away from the lower stage, and are moved toward the lower stage to attach the first and second films to the sides of the electrode assembly.

10. The pair of side sealing blocks are 10. The method of claim 9, wherein a negative pressure is applied to the first and second films while the first and second films are attached to the side surfaces of the electrode assembly to tightly seal the first and second films to the sealing surfaces, thereby preventing wrinkles from occurring.

11. 9. The method of claim 8, further comprising adjusting a distance between the sealing bars provided on the lower stage and the upper stage to correspond to a width of the electrode assembly.

12. The electrode assembly, the first film, and the second film are 9. The method for wrapping an electrode assembly according to claim 8, wherein the film and the electrode assembly stacked and accommodated in a film magazine and a cell magazine, respectively, are held by a carrier and moved onto the lower stage.

13. the first film and the second film include a heat-activated adhesive layer; 13. The method for wrapping an electrode assembly according to claim 8, wherein after wrapping of the bottom surface, the top surface, and the side surfaces of the electrode assembly is completed, the first film and the second film are heated to adhere the first film and the second film to the electrode assembly.

14. the adhesive layer is an EVA layer, The method of claim 13, wherein the adhesive action of the EVA layer is activated at a temperature in the range of 140±20°C.

15. an electrode assembly in which a plurality of battery cells are stacked; a first film attached to a bottom surface and both side surfaces of the electrode assembly; and The electrode assembly includes a second film attached to the top and both side surfaces of the electrode assembly.

16. The electrode assembly of claim 15 , wherein the second film is attached to both sides of the electrode assembly so as to overlap the first film.

17. The electrode assembly of claim 15 , wherein the first film and the second film are PET films.

18. The electrode assembly of claim 15 , wherein an adhesive layer is interposed between the first film, the second film, and the electrode assembly.

19. the adhesive layer is an EVA layer, 20. The electrode assembly of claim 18, wherein the EVA layer has heat-activated adhesive properties.

20. The first film and the second film are The electrode assembly of claim 15 , wherein the bottom, top, and both side surfaces of the electrode assembly are not exposed.

21. The first film and the second film are 21. The electrode assembly of claim 15, wherein a compressive force is applied across the bottom, top and both side surfaces of the electrode assembly.

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