Device and method for folding a sealing portion of a pouch-type battery cell

Abstract

The present invention relates to a device and method for folding a sealing part of a pouch-type battery cell, and more particularly, to a device and method for folding a sealing part of a pouch-type battery cell, comprising: a lower unit including a lower folding block on which a sealing part is seated and capable of horizontal reciprocating motion and vertical movement; an upper unit including an upper folding block located above the lower unit, capable of horizontal reciprocating motion and vertical movement, and for pressing the sealing part to fold it at a certain angle; a lower folding guide unit located in front of the lower unit, capable of vertical movement, and for guiding the sealing part to fold it at a certain angle; and an upper folding guide unit located in front of the upper unit, capable of vertical movement, and for guiding the sealing part to fold it at a certain angle.

Description

[Technical field]

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0119747 filed on September 22, 2022, and Korean Patent Application No. 10-2023-0097591 filed on July 26, 2023, and all contents disclosed in the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a device and method for folding a sealing part of a pouch-type battery cell, and more particularly to a device and method for folding a sealing part of a pouch-type battery cell, which can fold a sealing part at various angles and perform a folding process accurately at a predetermined position regardless of the width of a battery cell. [Background technology]

[0003] Recently, the demand for secondary batteries that can store electrical energy produced by the development of alternative energy sources due to air pollution caused by the use of fossil fuels and energy depletion is increasing. Secondary batteries that can be charged and discharged are closely used in daily life, such as mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Secondary batteries are used as energy sources for various electronic devices that are essential in modern society, and the required capacity is increasing due to the increased use and complication of mobile devices and the development of electric vehicles, etc. To meet user demand, many battery cells are arranged in small devices, while automobiles and the like use battery modules that electrically connect many battery cells or battery packs equipped with many such battery modules.

[0005] To manufacture a pouch-type battery cell of a secondary battery, an electrode assembly is placed in a case having a pocket, and the edge of the case, which is a wing, is sealed. Then, an activation process, a degassing process, a resealing process, and a folding process of the sealed wing are sequentially performed.

[0006] Meanwhile, as devices to which secondary batteries are applied become more diverse and the demand for secondary batteries with high energy density increases, the length of pouch-type battery cells is becoming longer. However, in the case of wings, the middle part is relatively flexible compared to the edge part, so there are cases where the wing is folded at the outer periphery rather than along a fixed folding line, which inevitably leads to product defects.

[0007] In this regard, a prior document (Korean Patent Registration No. 1974443) discloses an automatic terrace folding device for secondary battery cells, in which a secondary battery is seated on a carrier and automatically transported while being folded in three stages to 90°, 180°, and 270° in sequence, the first 90° is folded to 90° using a folding blade, and when folding to 180°, a roller pushes the terrace in a vertically folded state to perform the 180° folding operation, and when folding to 270°, the terrace folded to 180° is pushed from the bottom to the top to fold to 270°.

[0008] However, in the case of the prior art, the terraces of the secondary battery are folded by 90° each time to 180° or 270°, which requires multiple folding devices, resulting in low process efficiency and high equipment purchase costs. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent No. 1974443 Summary of the Invention [Problem to be solved by the invention]

[0010] In order to solve the above problems, the present invention aims to provide a folding device and folding method for a sealing portion of a pouch-type battery cell that can fold the sealing portion of a secondary battery at 90°, 180°, 270°, and 360° using a single folding device.

[0011] Another object of the present invention is to provide a device and method for folding a sealing portion of a pouch-type battery cell, which can fold the battery cell at a fixed position regardless of the length of the battery cell. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides a device for folding a sealing part of a pouch-type battery cell, which folds a sealing part of a pouch-type battery cell in which an electrode assembly is housed in a cell case (11), electrode leads (12) protrude from one or both sides of the cell case (11), and a sealing part (14) is provided on three or four sides of the edge of the cell case (11). The device comprises a lower unit (100) including a lower folding block (110) on which the sealing part (14) is seated and which is capable of horizontal reciprocating motion and vertical movement, and a lower folding block (110) located above the lower unit (100) which is capable of horizontal reciprocating motion and vertical movement. The folding folding device includes an upper unit (200) including an upper folding block (210) that is movable and presses the sealing part (14) to fold it at a certain angle, a lower folding guide part (300) located in front of the lower unit (100) that is movable up and down and guides the sealing part (14) to fold it at a certain angle, and an upper folding guide part (400) located in front of the upper unit (200) that is movable up and down and guides the sealing part (14) to fold it at a certain angle.

[0013] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the upper folding block (210) has a length equal to or greater than the length of the sealing part (14), and on its front surface facing the sealing part (14), a vertical surface (210(a)) and a first inclined surface (210(b)) cut downward are formed in that order from above.

[0014] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the upper folding block (210) is characterized in that it is composed of a first upper folding block (211), a second upper folding block (212) and a third upper folding block (213) arranged sequentially in line in the longitudinal direction of the sealing part (14).

[0015] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the second upper folding block (212) is arranged to protrude forward more than the first upper folding block (211) and the third upper folding block (213).

[0016] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the first upper folding block (211), the second upper folding block (212) and the third upper folding block (213) can be driven independently.

[0017] In addition, in the pouch-type battery cell sealing portion folding device of the present invention, the middle portion of the upper folding block (210) is formed to protrude forward beyond the edge portion.

[0018] In addition, in the pouch-type battery cell sealing portion folding device of the present invention, the edge portion of the upper folding block (210) is formed to protrude forward beyond the middle portion.

[0019] In addition, in the pouch-type battery cell sealing part folding device of the present invention, at least one of the lower folding block (110) and the upper folding block (210) is characterized by having a heating means for heating to a certain temperature.

[0020] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the lower folding guide part (300) includes a lower blade (310) having a length equal to or greater than the length of the sealing part (14), and a second inclined surface (311) inclined at a certain angle is formed on an inner surface facing the lower unit (100) so that the thickness decreases toward the top.

[0021] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the upper folding guide part (400) includes an upper blade (410), which has a length equal to or greater than the length of the sealing part (14), and is cut downward on its outer surface to form a third inclined surface 411 inclined at a certain angle.

[0022] In addition, in the pouch-type battery cell sealing part folding device of the present invention, a recess (412) is formed on the inner surface of the upper blade (410) so as to accommodate a portion of the vertical surface (210(a)) and the first inclined surface (210(b)) when the upper folding block (210) approaches.

[0023] In addition, in the pouch-type battery cell sealing part folding device of the present invention, the central axis of the lower blade (310) and the central axis of the upper blade (410) move up and down on the same vertical line.

[0024] In addition, the method of folding a sealing part of a pouch-type battery cell of the present invention is a method of folding a sealing part of a pouch-type battery cell in which an electrode assembly is accommodated in a cell case (11), electrode leads (12) protrude from one or both sides of the cell case (11), and a sealing part (14) is provided on three or four sides of the edge, the method including a first step of positioning the sealing part (14) on an upper part of a lower folding block (110), a second step of raising a lower blade (310) to bring the sealing part (14) into close contact with a bottom surface of the sealing part (14), a third step of lowering an upper blade (410) between the lower folding block (110) and the lower blade (310) to fold the sealing part (14) at a first angle (a1), and a fourth step of raising the lower folding block (110) to fold the sealing part (14) from the first angle (a1) to a second angle (a2). a fifth step of lowering the lower folding block (110); a sixth step of lowering the upper folding block (210); a seventh step of advancing the upper folding block (210) to bend the folding bar from the second angle (a2) to the third angle (a3); an eighth step of moving the upper folding block (210) backward; a ninth step of lowering the lower blade (310) and lifting the upper blade (410); a tenth step of lifting the upper folding block (210); an eleventh step of advancing the lower folding block (110); a twelfth step of lifting the lower folding block (110); and a thirteenth step of advancing the upper folding block (210) to bend the folding bar from the third angle (a3) ​​to the fourth angle (a4).

[0025] In addition, the method for folding a sealing part of a pouch-type battery cell of the present invention further includes a fourteenth step of lowering the upper folding block (210) and folding the sealing part at a fifth angle (a5).

[0026] In addition, in the method for folding a sealing portion of a pouch-type battery cell of the present invention, the first angle (a1) and the second angle (a2) are obtuse angles, and the third angle (a3) ​​and the fourth angle (a4) are acute angles.

[0027] In the method for folding a sealing portion of a pouch-type battery cell of the present invention, the fifth angle (a5) is 0°.

[0028] In addition, in the sealing portion folding method of the pouch-type battery cell of the present invention, in order to fold the middle portion of the sealing portion (14) before the two side portions in the seventh step, the upper folding block (210) is composed of a first upper folding block (211), a second upper folding block (212) and a third upper folding block (213) arranged sequentially in a line in the longitudinal direction of the sealing portion (14), and the second upper folding block (212) protrudes forward more than the first upper folding block (211) and the third upper folding block (213). Effect of the Invention

[0029] As described above, according to the device and method for folding a sealing part of a pouch-type battery cell of the present invention, the upper folding block, lower folding block, lower blade and upper blade, which support or press or guide the sealing part, can move not only horizontally but also vertically, which has the advantage that the sealing part of the secondary battery can be folded at various angles.

[0030] In addition, according to the device and method for folding a sealing portion of a pouch-type battery cell of the present invention, the upper folding block is made up of a number of unit folding blocks that can be moved independently, which has the advantage that folding can be performed at a fixed position regardless of the length of the battery cell. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view of a pouch-type battery cell according to the present invention. [Diagram 2] 1 is a side view showing a folding device for a sealing portion of a pouch-type battery cell according to a first preferred embodiment of the present invention; [Diagram 3] 3 is a perspective view of an upper folding unit constituting the sealing portion folding device shown in FIG. 2. [Figure 4] FIG. 4 is a plan view of the upper folding unit shown in FIG. 3. [Diagram 5] FIG. 13 is a perspective view of an upper folding unit constituting a folding device for a sealing portion of a pouch-type battery cell according to a second preferred embodiment of the present invention. [Figure 6] FIG. 6 is a plan view of the upper folding unit shown in FIG. 5. [Figure 7] FIG. 13 is a perspective view of an upper folding unit constituting a folding device for a sealing portion of a pouch-type battery cell according to a third preferred embodiment of the present invention. [Figure 8] FIG. 8 is a plan view of the upper folding unit shown in FIG. [Figure 9] 4 is a flowchart illustrating a folding method using the folding device for a sealing portion of a pouch-type battery cell according to a first preferred embodiment of the present invention. [Figure 10] 5A to 5C are diagrams illustrating the operation of a folding device in a first step and a second step in the method for folding a sealing portion of a pouch-type battery cell of the present invention. [Figure 11] 11A to 11D are views for explaining the operation of the folding device in the third and fourth steps in the method for folding a sealing portion of a pouch-type battery cell of the present invention. [Figure 12]11A to 11C are views for explaining the operation of a folding device in a fifth step and a sixth step in the method for folding a sealing portion of a pouch-type battery cell of the present invention. [Figure 13] 11A to 11C are views for explaining the operation of a folding device in the seventh and eighth steps in the method for folding a sealing portion of a pouch-type battery cell of the present invention. [Figure 14] 10A to 10C are views for explaining the operation of a folding device in a ninth step and a tenth step in the method for folding a sealing portion of a pouch-type battery cell according to the present invention. [Figure 15] 11A to 11C are diagrams illustrating the operation of a folding device in steps 11 and 12 in the method for folding a sealing portion of a pouch-type battery cell of the present invention. [Figure 16] 13A to 14C are diagrams illustrating the operation of a folding device in steps 13 and 14 in the method for folding a sealing portion of a pouch-type battery cell of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, when describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0033] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, unless otherwise specified, the term "including a certain component" does not mean to exclude other components, but means that the part may further include other components.

[0034] Hereinafter, a folding device and a folding method for a sealing portion of a pouch-type battery cell according to the present invention will be described with reference to the accompanying drawings.

[0035] Fig. 1 is a perspective view of a pouch-type battery cell according to the present invention. As shown in Fig. 1, a pouch-type battery cell 10, which is the subject of the folding device and folding method according to the present invention, has an electrode assembly housed inside a cell case 11 composed of an upper case 11(a) and a lower case 11(b). Electrode leads 12 connected to electrode tabs of the electrode assembly protrude from both sides of the cell case 11, and three sides of the edge of the cell case 11 are sealed.

[0036] Here, the portion to be folded is a surface of the three sealing portions 14 from which the electrode leads 12 do not protrude, and is folded along a folding line 14' of the sealing portions 14, which are so-called wing portions.

[0037] Although the drawings show three sides as sealing portions, in the case where the upper case and the lower case are not connected, four sides correspond to the sealing portion, and it goes without saying that a unidirectional battery cell in which the electrode leads are exposed in the same direction can also be folded using the folding device of the present invention.

[0038] On the other hand, the cell case 11 is made by punching a laminate sheet consisting of an outer resin layer, a metal layer, and an inner resin layer to form a pocket portion.

[0039] The external resin layer is located on the outer periphery of the cell case 11. This external resin layer may be made of a heat-resistant polymer having excellent tensile strength, moisture permeability, and air permeability so as to ensure heat resistance and chemical resistance while protecting the electrode assembly housed in the cell case. Examples of the material that may be used include, but are not limited to, nylon or polyethylene terephthalate.

[0040] The metal layer in contact with the external resin layer corresponds to a barrier layer that prevents moisture and various gases from penetrating into the interior of the battery from the outside. A suitable material for such a metal layer is an aluminum thin film, which is lightweight yet has excellent formability.

[0041] The inner resin layer must have insulating properties and electrolytic resistance since it is in direct contact with the electrode assembly, and must have sealing properties, i.e., excellent thermal adhesive strength at the sealing portion where the inner layers are thermally bonded to each other, in order to seal against the outside. The material for the inner resin layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and good sealing properties, polyurethane resins, and polyimide resins, but is not limited thereto, and polypropylene, which has excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact strength, and excellent chemical resistance, is the most preferable.

[0042] The electrode assembly may be, but is not limited to, a jelly roll type electrode assembly having a structure in which a long sheet-like negative electrode and positive electrode are wound with a separator interposed between them, a stack type electrode assembly composed of unit cells having a structure in which rectangular positive and negative electrodes are stacked with a separator interposed between them, a stack folding type electrode assembly in which unit cells are wound with a long separator film, or a lamination stack type electrode assembly in which unit cells are stacked with a separator interposed between them and attached to each other.

[0043] Meanwhile, in the specification of the present invention, the overall length direction corresponds to the X-axis direction, the overall width direction corresponds to the Y-axis direction, and the height direction corresponds to the Z-axis direction, based on the battery cell (see FIG. 1).

[0044] FIG. 2 is a side view showing a sealing portion folding device for a pouch-type battery cell according to a first preferred embodiment of the present invention, FIG. 3 is a perspective view of an upper folding unit that constitutes the sealing portion folding device shown in FIG. 2, and FIG. 4 is a plan view of the upper folding unit shown in FIG. 3.

[0045] The pouch-type battery cell sealing part folding device according to the present invention includes a lower unit 100, an upper unit 200, a lower folding guide part 300, and an upper folding guide part 400.

[0046] First, the lower unit 100 will be described. This is where the sealing part 14 of the battery cell sits, and it can perform horizontal reciprocating motion forward and backward in the overall width direction of the battery cell (Y-axis direction) and can also rise and fall in the height direction of the battery cell (Z-axis direction).

[0047] Specifically, the lower unit 100 may include a lower folding block 110, a first driving shaft 120, and a second driving shaft 130.

[0048] The lower folding block 110, which is a substantially hexahedral shape with a flat upper surface, is located under the sealing part to support the sealing part or to help fold the sealing part at a predetermined angle. Here, it is preferable that the length of the lower folding block 110 is equal to or greater than the length of the sealing part so that it can contact the entire part of the sealing part to be folded.

[0049] The first driving shaft 120 is connected to the lower folding block 110 and can move forward or backward in the overall width direction of the battery cell (Y-axis direction), and the second driving shaft 130 connected to the first driving shaft 120 can move up and down in the height direction of the battery cell (Z-axis direction).

[0050] Of course, although not shown in the drawings, a known driving means capable of linear motion, such as a servo motor or a cylinder, is connected to each of the first driving shaft 120 and the second driving shaft 130. Also, as long as the lower folding block 110 can be raised and lowered while horizontally reciprocating, the configuration is not necessarily limited to the above.

[0051] The upper unit 200 is located above the lower unit 100 and moves forward and backward horizontally in the width direction of the battery cell (Y-axis direction) and upward and downward in the height direction of the battery cell (Z-axis direction) to press the sealing portion and bend it at a certain angle.

[0052] Specifically, the upper unit 200 may include an upper folding block 210 , a third driving shaft 220 , and a fourth driving shaft 230 .

[0053] The upper folding block 210 is located above the lower folding block 110 and presses the sealing portion to bend it at a predetermined angle, preferably having a length equal to or greater than the length of the sealing portion so as to contact the entire portion of the sealing portion to be folded.

[0054] The upper folding block 210 has a generally hexahedral shape with a flat bottom surface, and preferably has a slightly inclined front surface. In particular, a vertical surface 210(a) that is perpendicular to the top surface of the lower folding block 110 is located at the top of the front surface, while a first inclined surface 210(b) that is cut downward and inclined is located below the vertical surface 210(a).

[0055] When folding the sealing part using the device of the present invention, the sealing part is folded 180 degrees by multiple folding processes. Here, if the upper folding block 210 has the first inclined surface 210(b), it can be easily folded 180 degrees. This will be described in detail later.

[0056] The third driving shaft 220 is connected to the upper folding block 210 and can move forward or backward in the overall width direction of the battery cell (Y-axis direction), and the fourth driving shaft 230 connected to the third driving shaft 220 can move up and down in the height direction of the battery cell (Z-axis direction).

[0057] Of course, although not shown in the drawings, each of the third driving shaft 220 and the fourth driving shaft 230 is connected to a known driving means for linear motion, such as a servo motor, a cylinder, etc. Also, as long as the upper folding block 210 can be raised and lowered while horizontally reciprocating, the above configuration is not necessarily limited.

[0058] Meanwhile, the upper folding block 210 may be composed of a plurality of unit folding blocks that can be driven independently, and the middle part may protrude relatively more than both side edges.

[0059] Specifically, as shown in Figures 3 and 4, the upper folding block 210 can be configured as a single upper folding block 210 by sequentially arranging a first upper folding block 211, a second upper folding block 212, and a third upper folding block 213 in the overall length direction (X-axis direction) of the battery cell.

[0060] Here, the second upper folding block 212 located in the middle protrudes slightly forward more than the first upper folding block 211 and the third upper folding block 213 located on either side. Of course, the front surfaces of the first upper folding block 211 to the third upper folding block 213 also have a vertical surface and a first inclined surface.

[0061] As described above, when folding the sealing portion of a long battery cell, the sealing portion in the middle is more flexible than the side edges, so that folding defects occur in which the sealing portion is bent before a specific folding line.

[0062] However, in the present invention, the upper folding block 210 has a structure in which the second upper folding block 212 protrudes a little longer toward the middle portion corresponding to the flexible sealing region, so that the folding failure can be reduced.

[0063] Furthermore, the first upper folding block 211, the second upper folding block 212 and the third upper folding block 213 are provided with a third (a) driving shaft 221, a third (b) driving shaft 222 and a third (c) driving shaft 223 so as to be able to move horizontally in the overall width direction (Y-axis direction) of the battery cell, and are connected to a fourth (a) driving shaft 231, a fourth (b) driving shaft 232 and a fourth (c) driving shaft 233 for raising and lowering, respectively. Therefore, it is also possible to individually adjust the protruding lengths of the first upper folding block 211, the second upper folding block 212 and the third upper folding block 213 in consideration of the electrical equipment of the battery cell.

[0064] The lower folding guide part 300 will now be described with reference to FIG.

[0065] The lower folding guide part 300 is configured to guide the sealing part to bend at a certain angle. It is located in front of the lower unit 100 and can move up and down in the height direction of the battery cell (Z-axis direction) and also can move forward and backward in the overall width direction of the battery cell (Y-axis direction) in a horizontal reciprocating motion.

[0066] Specifically, the lower folding guide unit 300 may include a lower blade 310 , a first support unit 320 , a fifth driving shaft 330 , and a sixth driving shaft 340 .

[0067] First, the lower blade 310 has a function of supporting the bottom surface of the sealing part so as to fold the sealing part at a predetermined angle, and therefore, it is preferable that the length of the lower blade 310 is equal to or greater than the length of the sealing part. The lower blade 310 has an inclined inner surface toward the lower unit 100, more specifically, a second inclined surface 311 inclined at a certain angle so that the thickness gradually decreases toward the upper folding guide part 400, and a first nip 312 is provided at the end.

[0068] This is to guide the sealing portion to be bent at a predetermined angle by securing a space between the upper blade 410 and the lower blade 310 when the upper blade 410 described later descends.

[0069] The first support part 320 is configured to support the lower blade 310, the fifth drive shaft 330 is connected to the first support part 320 and can move forward or backward in the overall width direction of the battery cell (Y-axis direction), and the sixth drive shaft 340 connected to the fifth drive shaft 330 can move up and down in the height direction of the battery cell (Z-axis direction).

[0070] Of course, although not shown in the drawings, known driving means for linear motion, such as a servo motor or a cylinder, are connected to each of the fifth driving shaft 330 and the sixth driving shaft 340. Also, as long as the lower blade 310 can be raised and lowered while horizontally reciprocating, the configuration is not necessarily limited to the above.

[0071] Furthermore, although the fifth driving shaft 330 has been described as being connected to the first support portion 320, it is also possible to omit the first support portion 320 and connect the fifth driving shaft 330 directly to the lower blade 310.

[0072] Meanwhile, in order to maintain the folded state of the sealing part, at least one of the lower folding block 110 and the upper folding block 210 may include a heating member (not shown). For example, a heating member (not shown) is accommodated inside the lower folding block 110 and the upper folding block 210 or attached to one outer surface thereof to increase the temperature of the sealing part during folding of the sealing part. In particular, when the sealing part is heated to a temperature above the melting point of the inner resin layer of the cell case, an improvement in insulation resistance can also be expected.

[0073] Next, the upper folding guide part 400 is configured to guide the sealing part to be folded at a certain angle. It is located in front of the upper unit 200 and can move up and down in the height direction of the battery cell (Z-axis direction) and also can move forward and backward in the overall width direction of the battery cell (Y-axis direction) in a horizontal reciprocating motion.

[0074] Specifically, the upper folding guide unit 400 may include an upper blade 410 , a second support unit 420 , a seventh driving shaft 430 , and an eighth driving shaft 440 .

[0075] First, the upper blade 410 has the function of pressing the upper surface of the sealing part to bend the sealing part at a predetermined angle, so it is preferable that the upper blade 410 is longer than the length of the sealing part, and further, a third inclined surface 411 is formed on the outer surface and a recessed portion 412 is provided on the inner surface.

[0076] Here, the third inclined surface 411 is preferably inclined at a certain angle so that the thickness decreases toward the bottom, and more preferably has the same angle as that of the lower blade 310, except for the position of the inclined surface.

[0077] This is to prevent the central axis of the lower blade 310 and the central axis of the upper blade 410 from colliding with each other in some sections even if they move up and down on the same vertical line.

[0078] A recess 412 provided on the opposite side of the third inclined surface 411, i.e., the surface facing the upper folding block 210, is configured to bend the sealing portion at an acute angle.

[0079] In detail, when the upper folding block 210 moves inward toward the upper blade 410 to press the sealing portion folded at a predetermined angle, the vertical surface 210(a) and the first inclined surface 210(b) of the upper folding block 210 can accommodate a part of the sealing portion together. Reference numeral 413 denotes a second nip.

[0080] The second support part 420 is configured to support the upper blade 410, the seventh drive shaft 430 is connected to the second support part 420 and can move forward or backward in the overall width direction of the battery cell (Y-axis direction), and the eighth drive shaft 440 connected to the seventh drive shaft 430 can move up and down in the height direction of the battery cell (Z-axis direction).

[0081] Of course, although not shown in the drawings, known driving means for linear motion, such as a servo motor or a cylinder, are connected to each of the seventh driving shaft 430 and the eighth driving shaft 440. Also, as long as the upper blade 410 can be raised and lowered while horizontally reciprocating, the configuration is not necessarily limited to the above.

[0082] Furthermore, although the seventh drive shaft 430 has been described as being connected to the second support portion 420, it is also possible to omit the second support portion 420 and have the seventh drive shaft 430 directly connected to the upper blade 410.

[0083] Meanwhile, in the case of the above-mentioned lower folding block 110, upper folding block 210, lower blade 310, and upper blade 410, it is preferable that the portions in contact with the sealing portion have a round shape with a predetermined radius of curvature so as to prevent the sealing portion from being damaged.

[0084] FIG. 5 is a perspective view of an upper folding unit constituting a folding device for a sealing portion of a pouch-type battery cell according to a second preferred embodiment of the present invention, and FIG. 6 is a plan view of the upper folding unit shown in FIG.

[0085] Except for the upper folding unit, the remaining structure is the same as that of the first embodiment described above. The upper folding block according to the first embodiment of the present invention is composed of multiple units, but the upper folding block 210 according to the second embodiment is composed of a single integrated member with a middle portion protruding forward from the edge.

[0086] FIG. 7 is a perspective view of an upper folding unit constituting a folding device for a sealing portion of a pouch-type battery cell according to a third preferred embodiment of the present invention, and FIG. 8 is a plan view of the upper folding unit shown in FIG.

[0087] Except for the upper folding unit, the remaining structure is the same as that of the first embodiment. The upper folding block according to the first embodiment of the present invention is composed of multiple units, but the upper folding block 210 according to the third embodiment is composed of an integrated single member with both side edges protruding forward more than the middle part. The upper folding block 210 according to the third embodiment can be used when the edges of the sealing part need to be folded before the middle part.

[0088] Next, a method for folding the sealing portion of a pouch-type battery cell using the above-mentioned folding device will be described.

[0089] Fig. 9 is a flow chart for explaining a method of folding using the folding device for a sealing portion of a pouch-type battery cell according to a first preferred embodiment of the present invention, Fig. 10 is a diagram for explaining the operation of the folding device in the first and second steps in the folding method for a sealing portion of a pouch-type battery cell of the present invention, Fig. 11 is a diagram for explaining the operation of the folding device in the third and fourth steps in the folding method for a sealing portion of a pouch-type battery cell of the present invention, and Fig. 12 is a diagram for explaining the operation of the folding device in the fifth and sixth steps in the folding method for a pouch-type battery cell of the present invention.

[0090] In addition, Figure 13 is a diagram for explaining the operation of the folding device in the 7th and 8th steps in the folding method of the sealing portion of a pouch-type battery cell of the present invention, Figure 14 is a diagram for explaining the operation of the folding device in the 9th and 10th steps in the folding method of the sealing portion of a pouch-type battery cell of the present invention, Figure 15 is a diagram for explaining the operation of the folding device in the 11th and 12th steps in the folding method of the sealing portion of a pouch-type battery cell of the present invention, and Figure 16 is a diagram for explaining the operation of the folding device in the 13th and 14th steps in the folding method of the sealing portion of a pouch-type battery cell of the present invention.

[0091] 9 to 16, the method for folding a sealing part of a pouch-type battery cell according to the present invention first performs a first step of positioning the sealing part 14 on the upper part of the lower folding block 110 of the lower unit 100 (see FIG. 10(a)).

[0092] Here, the lower blade 310 and the upper blade 410 are located on the same vertical line and are spaced a certain distance from the bottom and top of the sealing part 14, respectively, and are slightly spaced from the sealing part 14 and the top surface of the lower folding block 110 to easily fold the sealing part.

[0093] The folding line 14 ′ of the sealing portion 14 is located on the same vertical line as the second nip 413 , which is the end of the upper blade 410 .

[0094] 1, the battery cell has an electrode assembly 13 housed in a cell case 11, electrode leads protruding from both sides of the cell case 11, and sealing portions 14 provided on three sides of the edge. Of course, the battery cell may be unidirectional, with the electrode lead 12 protruding to one side, or may have sealing portions on all four sides of the edge.

[0095] In the second stage, the lower blade 310 of the lower folding guide part 300 located in front of the lower unit 100 is raised to bring the first nip 312 into close contact with the bottom surface of the sealing part 14 (see FIG. 10(b)).

[0096] Here, the position where the first nip 312 and the sealing portion 14 come into close contact with each other is in front of the folding line 14'.

[0097] In the third step, the upper blade 410 of the upper folding guide part 400 is lowered to fold the sealing part 14 at the first angle a1. Specifically, the upper blade 410 is lowered to the folding line 14' located between one side end of the lower folding block 110 and the lower blade 310, thereby obtaining the sealing part 14 bent at the first angle a1 and the first' angle a1' (see FIG. 11(c)).

[0098] Here, the first angle a1 is the angle of the folding line 14', specifically, the angle between the sealing portion between the first nip 312 of the lower blade 310 and the second nip 413 of the upper blade 410, and the sealing portion between the second nip 413 and the end of the sealing portion, and is an obtuse angle.

[0099] The first angle a1' is an angle formed between the sealing portion located in front of the first nip 312 and the sealing portion located between the first nip 312 and the second nip 413, and is also an obtuse angle.

[0100] The fourth step is to raise the lower folding block 110 and bend the first angle a1 to the second angle a2 (see FIG. 11(d)). That is, when the lower folding block 110 is raised, the upper edge of one end of the lower folding block 110 pushes the sealing part 14 upward, thereby bending it to the second angle a2, which is relatively smaller than the first angle a1 obtained in the third step.

[0101] In the fifth step, the lower folding block 110, which was raised in the fourth step, is lowered and returned to its original position (see FIG. 12(e)).

[0102] The sixth step is to lower the upper folding block 210 (see FIG. 12(f)). In detail, the upper folding block 210 of the upper unit 200 located behind the upper folding guide part 400 is lowered. At this time, it is preferable that the bottom surface of the upper folding block 210 and the top surface of the lower folding block 110 are very close to each other so as not to come into contact with each other.

[0103] The seventh step is to advance the upper folding block 210 to fold from the second angle a2 to the third angle a3 (see FIG. 13(g)). That is, the upper folding block 210 is advanced toward the upper blade 410 until the sealing portion 14 located on one side of the second nip 413 of the upper blade 410 comes into close contact with the recess 412 of the upper blade 410, and the sheet is folded to the third angle a3, which is relatively smaller than the second angle a2.

[0104] In particular, as shown in Figures 3 and 4, by using an upper folding block 210 in which a first upper folding block 211, a second upper folding block 212, and a third upper folding block 213 are arranged in sequence, and moving the second upper folding block 212, which is located in the middle more than the first upper folding block 211 and the third upper folding block 213 on both sides, forward in a slightly protruding state, it is possible to minimize folding defects that occur in the middle of the sealing portion 14.

[0105] Meanwhile, the vertical surface 210(a) and the first inclined surface 210(b) of the upper folding block 210 are positioned in the recess 412 of the upper blade 410, and the third angle a3 formed by bending is an acute angle.

[0106] The eighth step is a step of moving the upper folding block 210 backward so as to return it to the position of the sixth step (see FIG. 13(h)).

[0107] The ninth step is to lower the lower blade 310 and raise the upper blade 410 (see FIG. 14(i)), and the tenth step is to raise the upper folding block 210 (see FIG. 14(j)).

[0108] Meanwhile, in the tenth step, it is preferable that the upper surface of the sealing portion 14 located between the unfolded sealing portion 14, for example the portion folded at the first 'angle a1', and the pocket portion of the cell case 11, is spaced apart from the bottom surface of the upper folding block 210 by a distance that is more than twice the thickness of the sealing portion 14. This is to facilitate folding of the sealing portion 14 in the subsequent step.

[0109] The 11th step is to advance the lower folding block 110 a predetermined distance (see FIG. 15(k)), and the 12th step is to raise the lower folding block 110 so that the sealing portions 14 located in the front and rear are aligned in a straight line based on the first 'angle a1' (see FIG. 15(l)).

[0110] In FIG. 15(l) showing the twelfth stage, the first' angle a1' is shown as having disappeared, i.e., as having been completely expanded, but it may remain as an obtuse angle larger than the first' angle a1'.

[0111] The thirteenth step is a step of bending from the third angle a3 to the fourth angle a4 (see FIG. 16(m)). The upper folding block 210 is advanced so that the sealing portion 14 is completely folded based on the folding line 14', thereby bending the sealing portion 14 from the third angle a3 to the fourth angle a4. Here, the fourth angle a4 is an acute angle relatively smaller than the third angle a3 and may be almost close to 0°.

[0112] The final 14th step is a step of folding at a fifth angle a5 corresponding to 0°, in which the upper folding block 210 is lowered so that there is no gap between the lower folding block 110, the sealing portion 14, and the upper folding block 210, and the sealing portion 14 is completely folded with the folding line 14' as the boundary (see (n) of Figure 16).

[0113] After the above-mentioned first to fourteenth steps, the sealing portion 14 is folded 180° with the folding line 14' as the boundary.

[0114] Thereafter, the upper folding block 210 is raised or the lower folding block 110 is lowered, and then the battery cell 10 is separated from the folding device.

[0115] If it is desired to fold the sealing portion 14 again, the above-mentioned first to fourteenth steps can be repeated to obtain a battery cell 10 that has been folded twice.

[0116] Meanwhile, the lower folding block 110 and the upper folding block 210 can be heated to a constant temperature while performing the above-mentioned steps 1 to 14, or can be heated only in the 13th and 14th steps.

[0117] Those skilled in the art will appreciate that the present invention can be applied in a variety of ways and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0118] 10 Pouch-type battery cells 11 Cell Case 11(a) Upper Case 11(b) Lower case 12 Electrode Lead 13 Electrode assembly 14 Sealing section 14' Folding Line 100 Lower Unit 110 Lower Folding Block 120 First drive shaft 130 Second drive shaft 200 Upper Unit 210 Upper Folding Block 210(a) Vertical plane 210(b) First slope 211 First Upper Folding Block 212 Second Upper Folding Block 213 3rd Upper Folding Block 220 3rd drive shaft 221 3rd (a) drive shaft 222 3rd (b) Drive shaft 223 3rd (c) Drive shaft 230 4th drive shaft 231 4th (a) drive shaft 232 4th (b) Drive shaft 233 4th (c) Drive shaft 300 Lower folding guide part 310 Lower Blade 311 2nd slope 312 First Nip 320 1st support part 330 5th drive shaft 340 6th Drive Shaft 400 Upper folding guide part 410 Upper blade 411 Third slope 412 Depression 413 2nd Nip 420 Second support part 430 7th Drive Shaft 440 8th Drive Shaft a1 First angle a1' 1st angle a2 2nd angle a3 3rd angle a4 4th angle a5 5th angle L total length W Full width

Claims

1. An apparatus for folding a sealing portion of a pouch-type battery cell, the pouch-type battery cell including an electrode assembly housed in a cell case, electrode leads protruding from one or both sides of the cell case, and sealing portions provided on three or four sides of an edge of the cell case, the apparatus comprising: a lower unit including a lower folding block on which the sealing portion is seated and which is capable of horizontal reciprocating motion and vertical movement; an upper unit including an upper folding block, the upper unit being located above the lower unit and capable of horizontal reciprocating motion and vertical motion, for pressing the sealing part to bend it at a certain angle; a lower folding guide unit located in front of the lower unit and capable of ascending and descending motion to guide the sealing unit to bend at a certain angle; an upper folding guide unit located in front of the upper unit, capable of ascending and descending motion, and for guiding the sealing unit to be folded at a certain angle.

2. 2. The folding device for a sealing portion of a pouch-type battery cell according to claim 1, wherein the upper folding block has a length equal to or greater than the length of the sealing portion, and a front surface facing the sealing portion is formed with a vertical surface and a first inclined surface cut downward, successively from above.

3. 3. The folding device for a sealing portion of a pouch-type battery cell according to claim 2, wherein the upper folding block comprises a first upper folding block, a second upper folding block, and a third upper folding block that are sequentially arranged in line in a longitudinal direction of the sealing portion.

4. 4. The pouch-type battery cell sealing portion folding device according to claim 3, wherein the second upper folding block is disposed so as to protrude further forward than the first upper folding block and the third upper folding block.

5. The pouch-type battery cell sealing portion folding device according to claim 3 , wherein the first upper folding block, the second upper folding block, and the third upper folding block are independently operable.

6. The pouch-type battery cell sealing portion folding device according to claim 2 , wherein the middle portion of the upper folding block is formed to protrude forward beyond the edge portion.

7. The pouch-type battery cell sealing portion folding device according to claim 2 , wherein an edge portion of the upper folding block is formed to protrude forward more than an intermediate portion.

8. 2. The folding device for a sealing portion of a pouch-type battery cell according to claim 1, wherein at least one of the lower folding block and the upper folding block is provided with a heating means for heating the lower folding block to a certain temperature.

9. 3. The folding device for a sealing portion of a pouch-type battery cell according to claim 2, wherein the lower folding guide portion includes a lower blade, the lower blade having a length equal to or greater than a length of the sealing portion, and a second inclined surface inclined at a certain angle such that a thickness decreases upward on an inner surface facing the lower unit.

10. 10. The folding device for a sealing portion of a pouch-type battery cell according to claim 9, wherein the upper folding guide portion includes an upper blade, the upper blade having a length equal to or greater than a length of the sealing portion, and an outer surface of the upper folding guide portion is cut downward to form a third inclined surface inclined at a certain angle.

11. 11. The pouch-type battery cell sealing portion folding device according to claim 10, wherein an inner surface of the upper blade has a recess formed thereon to accommodate a portion of the vertical surface and the first inclined surface when the upper folding block approaches.

12. The folding device for a sealing portion of a pouch-type battery cell according to claim 11 , wherein the central axis of the lower blade and the central axis of the upper blade move up and down on the same vertical line.

13. A method for folding a sealing portion of a pouch-type battery cell, the method comprising: housing an electrode assembly in a cell case; folding a sealing portion of the pouch-type battery cell in which electrode leads protrude from one or both sides of the cell case and sealing portions are provided on three or four sides of an edge of the cell case; A first step of positioning a sealing portion on an upper portion of a lower folding block; A second step of raising the lower blade to contact the bottom surface of the sealing portion; a third step of lowering an upper blade between the lower folding block and the lower blade to fold the sealing portion at a first angle; a fourth step of lifting the lower folding block to fold the folding member from the first angle to a second angle; a fifth step of lowering the lower folding block; a sixth step of lowering the upper folding block; a seventh step of advancing the upper folding block to fold the folding member from the second angle to a third angle; an eighth step of moving the upper folding block backward; a ninth step of lowering the lower blade and raising the upper blade; A tenth step of raising the upper folding block; an eleventh step of advancing the lower folding block; A twelfth step of raising the lower folding block; and a thirteenth step of advancing the upper folding block to fold the sealing portion from the third angle to a fourth angle.

14. The method for folding a sealing portion of a pouch-type battery cell according to claim 13 , further comprising a fourteenth step of lowering the upper folding block and folding the sealing portion at a fifth angle.

15. 15. The method for folding a sealing portion of a pouch-type battery cell according to claim 14, wherein the first angle and the second angle are obtuse angles, and the third angle and the fourth angle are acute angles.

16. The method for folding a sealing portion of a pouch-type battery cell according to claim 14 , wherein the fifth angle is 0°.

17. 14. The method of claim 13, wherein in the seventh step, the upper folding block includes a first upper folding block, a second upper folding block, and a third upper folding block that are sequentially arranged in a longitudinal direction of the sealing part so that the middle part of the sealing part is folded before the two side parts of the sealing part, and the second upper folding block protrudes forward more than the first upper folding block and the third upper folding block.

Images