Bending device and method for manufacturing laminated battery

Abstract

To provide a bending device capable of bending an edge seal portion as intended.SOLUTION: A bending device bends an edge seal portion extending in a first direction of a laminated battery. The edge seal portion is formed by welding end portions of a laminate film. The bending device includes a bending roller group and a pair of bending rollers. The bending roller group comprises: a lower roller that supports a first portion on the base side of the edge seal portion from below; an inner roller that presses at least a part of the first portion from above; and an outer roller that presses a second portion, located closer to the tip side relative to the first portion of the edge seal portion, toward the inner roller to form a bent portion. The pair of bending rollers comprises a first roller and a second roller whose axial directions of rotation shafts are parallel to each other in the first direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a folding device and a method for manufacturing a laminated battery. [Background technology]

[0002] To improve the volumetric efficiency of laminated batteries, the edge seal region of the exterior body made of laminated film is folded and formed by welding the edges of the laminated film together.

[0003] Patent Document 1 discloses a battery manufacturing apparatus. The battery includes a laminated exterior body and an electrode assembly. The laminated exterior body houses the electrode assembly. In a plan view, the laminated exterior body includes a seal portion (hereinafter also referred to as an "edge seal portion") on at least a portion of its periphery. The edge seal portion includes an area where the laminated exterior body is folded. The manufacturing apparatus may include a folding device. The folding device folds the edge seal portion by rolling. The folding device includes one or more rolls. The rolls include tapered portions. In the tapered portions, the roll diameter gradually decreases toward the axial end. The folding device is configured so that, while rotating the rolls, the tapered portions are pressed against the laminated exterior body, thereby folding the laminated exterior body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-059425 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 does not disclose a folding device that can fold the partially folded edge seal portion as intended.

[0006] In addition, the bending device disclosed in Patent Document 1 may not be able to bend the edge seal portion as intended in the region of the edge seal portion due to springback. "Springback" refers to a phenomenon in which at least a portion of the deformation caused by pressure tends to return to its original shape due to the driving force of residual stress generated by the deformation.

[0007] The present disclosure has been made in consideration of the above circumstances. An object of one embodiment of the present disclosure is to provide a folding device that can fold an edge seal portion as intended, and a method for manufacturing a laminated battery. [Means for solving the problem]

[0008] The means for solving the above problems include the following embodiments.

[0009] <1> The bending device of the first aspect is A folding device for folding an edge seal portion extending in a first direction of a laminated battery, The edge seal portion is formed by welding the edges of the laminate film together, The folding device includes a folding roller group and a pair of folding rollers, The bending roller group a lower roller that supports a first portion of the base side of the edge seal portion from below; an inner roller that presses at least a part of the first portion from above; an outer roller that presses a second portion of the edge seal portion that is closer to the tip end than the first portion toward the inner roller to form the bent portion; The pair of folding rollers is a folding device including a first roller and a second roller whose rotation axes are parallel to the first direction.

[0010] In this disclosure, "laminate film" refers to a film having at least a metal layer, a first resin layer laminated on one main surface of the metal layer, and a second resin layer laminated on the other main surface of the metal layer. "Main surface" refers to the surface with the largest area among the outer surfaces. "Bending the non-folding portion" refers to forming a folding portion in the non-folding portion that is bent relative to the main surface of the battery.

[0011] The folding device of the first aspect includes a folding roller group and a pair of folding rollers, and as a result, the folding device of the first aspect can fold the edge seal region more precisely than a folding device that does not include at least one of the folding roller group and the pair of folding rollers.

[0012] <2> The bending device of the second aspect is The edge seal region has a folding region that is folded at least once and a non-folding region, the pair of folding rollers are a pair of folding rollers that fold the non-folding portion with the first base line as a folding line, the first base line is located closer to the base of the edge seal region than an overlapping region of the non-folded region that overlaps with the folded region, The second roller is disposed on the folding portion side, the first roller includes a small diameter portion and a first tapered portion connected to the small diameter portion and having a diameter increasing toward a side opposite to the small diameter portion in the first direction, The second roller is a large diameter portion facing the small diameter portion and forming the first base line; a second tapered portion that faces the first tapered portion and has a diameter that decreases toward a side opposite to the large diameter portion in the first direction; a connecting portion that connects the large diameter portion and the second tapered portion and forms a gap between the first tapered portion and the second tapered portion; Including, The length of the gap in a direction perpendicular to the surface of the first tapered portion is longer than twice the thickness of the laminate film, and the second tapered portion has a length that restricts the opening of the folded portion. <1> 2. The bending device according to claim 1.

[0013] When the length of the gap in a direction perpendicular to the surface of the first tapered portion (hereinafter also referred to as the "gap interval") is less than twice the thickness of the laminate film, the portion of the edge seal region within the gap is likely to come into contact with the pair of folding rollers. As a result, the edge seal region is likely to be damaged by friction with the pair of folding rollers. In the second aspect, the gap interval is longer than twice the thickness of the laminate film. As a result, the portion of the edge seal region within the gap is less likely to come into contact with the pair of folding rollers than when the gap interval is less than twice the thickness of the laminate film. As a result, damage to the edge seal region due to friction with the pair of folding rollers is less likely to occur. When the gap distance is longer than the length over which the second tapered portion restricts the opening of the folded portion (hereinafter also referred to as the "restriction length"), the portion of the non-folded portion within the gap is likely to displace toward the second tapered portion of the second roller. This may result in both the folded portion and the non-folded portion being sandwiched between the small diameter portion of the first roller and the large diameter portion of the second roller. As a result, the first baseline may be formed in the overlapping portion of the non-folded portion where the folded portion overlaps. In addition, the folded portion may open due to springback, and a bent portion may be formed with the folded portion in an open state. As a result, the edge seal portion may not be folded as intended. In the second aspect, the spatial distance is the restriction length. This makes it difficult for the portion of the non-folded portion within the gap to displace toward the second tapered portion of the second roller. In addition, opening of the folded portion due to springback is prevented. As a result, the folding device of the second aspect can fold the edge seal portion more precisely.

[0014] <3> The bending device of the third aspect is The length of the second tapered portion that restricts the opening of the folded portion is four times or less the thickness of the laminate film. <2> 2. The bending device according to claim 1.

[0015] The folding device of the third aspect can fold the edge seal region more reliably and precisely than when the regulated length is more than four times the thickness of the laminate film.

[0016] <4> The bending device of the fourth aspect is a distance in the second direction between the position of the rotation shaft of the outer roller and the position of the rotation shaft of the lower roller is 1.0 to 3.5 times the length L; a distance in the second direction between the position of the rotation shaft of the outer roller and the position of the rotation shaft of the inner roller is 0.4 to 1.2 times the length L; the second direction is a direction perpendicular to the first direction, The length L indicates the length of the bent portion as viewed from the second direction. <1> ~ <3> 1. The bending device according to claim 1, wherein the bending device is a bending device for bending a metal plate.

[0017] When the distance in the second direction between the positions of the rotation shafts of the outer roller and the lower roller (hereinafter also referred to as the "first distance") is outside the range of 1.0 to 3.5 times the length L, the folding line is unlikely to be formed along the second direction. When the distance in the second direction between the positions of the rotation shafts of the outer roller and the rotation shafts of the inner roller (hereinafter also referred to as the "second distance") is outside the range of 0.4 to 1.2 times the length L, the folding line is unlikely to be formed along the second direction. In the fourth embodiment, the first distance is 1.0 to 3.5 times the length L, and the second distance is 0.4 to 1.2 times the length L. This allows the folding line to be formed along the second direction. As a result, the folding device of the fourth aspect can fold the edge seal region more precisely.

[0018] <5> The method for producing a laminated battery of the fifth aspect includes the steps of: The aforementioned <1> ~ <4> A method for manufacturing a laminated battery using the folding device according to any one of the above items, sandwiching the edge seal region between the folding roller group and folding the edge seal region along the second base line; and sandwiching the edge seal area between the pair of folding rollers and folding the edge seal area along a first base line located on the base side of the edge seal area relative to the second base line.

[0019] In the fifth aspect, the folding device according to any one of the first to fourth aspects is used, and as a result, the laminated battery manufacturing method of the fifth aspect can manufacture a laminated battery in which the edge seal region is folded as intended. [Effects of the Invention]

[0020] According to an embodiment of the present disclosure, a folding device capable of folding an edge seal portion in a targeted manner and a method for manufacturing a laminated battery are provided. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing the configuration of a bending device according to an embodiment. [Figure 2] FIG. 2 is a perspective view of a laminated battery according to an embodiment. [Figure 3] FIG. 3 shows a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is an external view of a group of bending rollers according to the embodiment. [Figure 5] FIG. 5 is an external view of a group of bending rollers according to the embodiment. [Figure 6] FIG. 6 is an external view of a pair of folding rollers according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0023] Hereinafter, an embodiment of a folding device and a manufacturing method of a laminated battery according to the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0024] (1) Bending device The folding device 1 according to this embodiment folds the edge seal region R11B of the transported battery 10. As shown in Fig. 1, the folding device 1 includes a transport section 20, a fixture 30 (see Fig. 5), an upstream roller group 40, and a downstream roller group 50. The upstream roller group 40 and the downstream roller group 50 are arranged in this order along the transport direction D of the battery 10.

[0025] In this embodiment, the transport direction D of the battery 10 is the positive X-axis direction, and the opposite side is the negative X-axis direction. The direction perpendicular to the X-axis direction is the Y-axis direction. The direction perpendicular to the X-axis and Y-axis directions is the Z-axis direction. The negative Z-axis direction is the direction of gravity. The X-axis direction is an example of the second direction. The Y-axis direction is an example of the first direction. The positive Z-axis direction is an example of the upward direction. The negative Z-axis direction is an example of the downward direction. Note that these directions do not limit the orientations of the folding device and rollers of the present disclosure when in use.

[0026] (1.1)Battery As shown in Fig. 2, the battery 10 includes an outer casing 11, an electrode assembly 12, and a pair of terminals 13. One of the pair of terminals 13 is a positive terminal. The other of the pair of terminals 13 is a negative terminal. The electrode assembly 12 is a rectangular parallelepiped.

[0027] The pair of terminals 13 are arranged opposite each other with the electrode body 12 interposed therebetween. Each of the pair of terminals 13 is electrically connected to the electrode body 12. The exterior body 11 covers the electrode body 12. The electrode body 12 is sealed by the pair of terminals 13 and the exterior body 11.

[0028] (1.1.1) Exterior body The exterior body 11 is made of a single laminate film. As shown in Fig. 3, the exterior body 11 has a housing region R11A and an edge seal region R11B. The housing region R11A houses the electrode assembly 12. The edge seal region R11B is formed by welding the ends of the laminate film together.

[0029] The edge seal region R11B has a folded region R11B10 that is folded once and a non-folded region R11B20 that is not folded. The non-folded region R11B20 has a bent region R11B21 and a non-folded region R11B22. The bent region R11B21 is bent relative to the main surface S12 of the electrode body 12. In this embodiment, the bending angle θA (see FIG. 3) of the bent region R11B21 relative to the main surface S12 is, for example, 90°. The non-folded region R11B22 extends in the positive Y direction from the end of the negative Z direction of the side surface of the storage region R11A that is in the positive Y direction. The folded region R11B10 and the bent region R11B21 face each other.

[0030] The laminate film is formed by laminating an outer insulating layer, a metal layer, and an inner insulating layer in this order. The thickness L11 of the laminate film (see FIG. 3) may be 70 μm to 220 μm. The outer insulating layer functions as a protective layer for the metal layer. Examples of materials for the outer insulating layer include polyethylene terephthalate (PET) and nylon. The metal layer blocks the passage of gas (e.g., moisture or air) between the outside and the inside of the battery 10. Examples of materials for the metal layer include aluminum, aluminum alloy, and stainless steel. The inner insulating layer electrically insulates the pair of terminals 13 and the electrode body 12 from the metal layer. Examples of materials for the inner insulating layer include polypropylene (PP) and polyethylene (PE).

[0031] (1.1.2) Electrode body The electrode body 12 functions as a power generating element of the battery 10. The electrode body 12 is covered with a laminate film. The electrode body 12 may be a known electrode body. The electrode body 12 may have a plurality of unit electrode bodies. The unit electrode body may include a so-called solid electrolyte (the content of the electrolytic solution as the electrolyte is less than 5 mass% of the total amount of the electrolyte) that uses an inorganic solid electrolyte as the electrolyte. The unit electrode body may have a structure in which a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector are stacked in this order along the Z-axis direction.

[0032] (1.1.3) Terminal The terminal 13 is a rectangular parallelepiped object. When viewed from the Z-axis direction, the terminal 13 has a U-shape. The terminal 13 may be made of a metal (for example, stainless steel (SUS)).

[0033] (1.2) Conveyor The conveying unit 20 is configured to convey the battery 10 in a conveying direction D. The conveying unit 20 may have any known configuration.

[0034] (1.3) Fixtures The fixing device 30 fixes the battery 10. More specifically, as the battery 10 passes through the bending device 1, the fixing device 30 prevents the battery 10 from being displaced in the Y-axis direction or the Z-axis direction relative to the bending device 1. In other words, the fixing device 30 helps to ensure that the folding region R11B10 and the bending region R11B21 are formed as intended. The fixing device 30 may have any known configuration.

[0035] (1.4) Upstream Roller Group The upstream roller group 40 folds the edge seal region R11B along a base line F1 (see FIG. 3) as a folding line to form a folding region R11B10. The base line F1 is an example of a second base line. The base line F1 extends along the X-axis. Hereinafter, when the folding region R11B10 is not formed, the portion of the edge seal region R11B corresponding to the folding region R11B10 is also referred to as the "folding region R11B10u." The folding region R11B10u is folded with respect to the main surface S12 of the electrode assembly 12. In other words, the upstream roller group 40 sets the folding angle θB (see FIG. 4) to a seventh angle (e.g., 180°) from 0°. The folding angle θB indicates the angle between the main surface S12 of the electrode assembly 12 and the folding region R11B10u when viewed from the X-axis direction.

[0036] The upstream roller group 40 includes a pair of rollers 41, a pair of rollers 42, a pair of rollers 43, a folding roller group 44, a pair of rollers 45, a pair of rollers 46, and a pair of rollers 47. The pair of rollers 41, the pair of rollers 42, the pair of rollers 43, the folding roller group 44, the pair of rollers 45, the pair of rollers 46, and the pair of rollers 47 are arranged in this order along the conveying direction D. The pairs of rollers 41 to 43, 45 to 47, and the folding roller group 44 rotate due to friction with the edge seal region R11B.

[0037] (1.4.1) A pair of rollers The pair of rollers 41 changes the bending angle θB from 0° to a first angle (e.g., 30°). The pair of rollers 42 changes the bending angle θB from the first angle to a second angle (e.g., 60°). The pair of rollers 43 changes the bending angle θB from the second angle to a third angle (e.g., 85°). Each of the pair of rollers 41, the pair of rollers 42, and the pair of rollers 43 may be a known pair of rollers.

[0038] (1.4.2) Bending roller group The folding roller group 44 changes the folding angle θB from the third angle to a fourth angle (e.g., 90°). Specifically, the folding roller group 44 moves relative to the fixture 30 along the X-axis direction (transport direction D). The folding roller group 44 sandwiches the edge seal region R11B of the battery 10 fixed to the fixture 30 that protrudes from the fixture 30 in the Y-axis direction, forming a folding region R11B10u (corresponding to the folding region R11B10). The folding roller group 44 rotates due to friction of the edge seal region R11B.

[0039] 4, the bending roller group 44 includes a lower roller 441, an inner roller 442, and an outer roller 443. In the Z-axis direction, the outer roller 443 is disposed between the lower roller 441 and the inner roller 442. The axial direction of the rotation axis A441 of the lower roller 441, the axial direction of the rotation axis A442 of the inner roller 442, and the axial direction of the rotation axis A443 of the outer roller 443 are not parallel to one another.

[0040] 5, the lower roller 441 supports a non-folding region R11B20 (corresponding to a first region) on the base side of the edge seal region R11B from the negative direction of the Z axis. The inner roller 442 presses a portion of the non-folding region R11B20 (i.e., a region near the base line F1) from the positive direction of the Z axis. The outer roller 443 presses the folding region R11B10u (corresponding to a second region closer to the tip than the first region) toward the inner roller 442 to form the folding region R11B10.

[0041] A distance LA (see FIG. 4) in the X-axis direction between the position of the rotation axis A443 of the outer roller 443 and the position of the rotation axis A441 of the lower roller 441 is 1.0 to 3.5 times the length L (see FIG. 5). A distance LB (see FIG. 4) in the X-axis direction (i.e., the first direction) between the position of the rotation axis A443 of the outer roller 443 and the position of the rotation axis A442 of the inner roller 442 is 0.4 to 1.2 times the length L. The length L indicates the length of the bending portion R11B10u (the length of the folding portion R11B10) as viewed from the X-axis direction.

[0042] The lower roller 441 has a large diameter portion 4411, a connecting portion 4412, and a small diameter portion 4413. The outer diameter of the large diameter portion 4411 is larger than the outer diameter of the small diameter portion 4413. The connecting portion 4412 connects the large diameter portion 4411 and the small diameter portion 4413. The large diameter portion 4411 supports the non-folding portion R11B20. The material of the lower roller 441 is not particularly limited and may be metal.

[0043] The inner roller 442 has a large diameter portion 4421, a connecting portion 4422, and a small diameter portion 4423. The outer diameter of the large diameter portion 4421 is larger than the outer diameter of the small diameter portion 4423. The connecting portion 4422 connects the large diameter portion 4421 and the small diameter portion 4423. The large diameter portion 4421 presses a portion of the non-folding portion R11B20 (i.e., a portion near the base line F1) from the positive direction of the Z axis. The material of the inner roller 442 is not particularly limited and may be metal.

[0044] The outer roller 443 has a circular cross section. The outer roller 443 may be chamfered. The material of the outer roller 443 is not particularly limited, and may be metal or rubber.

[0045] (1.4.3) A pair of rollers The pair of rollers 45 changes the bending angle θB from the fourth angle to a fifth angle (e.g., 120°). The pair of folding rollers 46 changes the bending angle θB from the fifth angle to a sixth angle (e.g., 150°). The pair of folding rollers 47 changes the bending angle θB from the sixth angle to a seventh angle (e.g., 180°). Each of the pair of folding rollers 45, the pair of folding rollers 46, and the pair of folding rollers 47 may be a known pair of rollers.

[0046] (1.5) Downstream Rollers The downstream roller group 50 folds the edge seal region R11B using a base line F2 (see FIG. 3) as a folding line to form a folding region R11B21. The base line F2 is an example of a first base line. The base line F2 extends along the X-axis. The base line F2 is located on the base side of the edge seal region R11B relative to the base line F1. In a state where the folding region R11B21 is not formed, the base line F2 is located closer to the electrode body 12 than the overlapping portion of the non-folding region R11B20 that overlaps with the folding region R11B10. In other words, the downstream roller group 50 sets the folding angle θA (see FIG. 3) from 0° to an eleventh angle (e.g., 90°).

[0047] The downstream roller group 50 includes a pair of folding rollers 51, a pair of folding rollers 52, a pair of folding rollers 53, and a pair of folding rollers 54. The pair of folding rollers 51, the pair of folding rollers 52, the pair of folding rollers 53, and the pair of folding rollers 54 are arranged in this order along the conveying direction D. The pairs of folding rollers 51 to 54 rotate due to friction with the edge seal region R11B.

[0048] (1.5.1) A pair of folding rollers The pair of folding rollers 51 sets the folding angle θA from 0° to an eighth angle (for example, 30°). Specifically, the pair of folding rollers 51 move relative to the fixing device 30 along the X-axis direction (first direction). The pair of folding rollers 51 sandwich the edge seal region R11B of the battery 10 fixed to the fixing device 30 that protrudes from the fixing device 30 in the Y-axis direction, and fold the non-folding region R11B20 using the base line F2 as a folding line.

[0049] As shown in Fig. 6, the pair of folding rollers 51 includes a first roller 511 and a second roller 512. The axial direction of the rotation axis A511 of the first roller 511, the axial direction of the rotation axis A512 of the second roller 512, and the Y-axis direction are parallel to one another. The first roller 511 and the second roller 512 rotate due to friction with the edge seal region R11B. The second roller 512 is disposed on the folding region R11B10 side (positive Z-axis side).

[0050] The first roller 511 includes a small diameter portion 5111, a first tapered portion 5112, and a large diameter portion 5113. The outer diameter of the small diameter portion 5111 is smaller than the outer diameter of the large diameter portion 5113. The first tapered portion 5112 connects the small diameter portion 5111 and the large diameter portion 5113. The diameter of the first tapered portion 5112 increases from the small diameter portion 5111 toward the large diameter portion 5113 (in the positive direction of the Y axis).

[0051] The second roller 512 includes a large diameter portion 5121, a connecting portion 5122, and a second tapered portion 5123. The large diameter portion 5121 of the second roller 512 faces the small diameter portion 5111 of the first roller 511. The large diameter portion 5121 forms a base line F2. The second tapered portion 5123 of the second roller 512 faces the first tapered portion 5112 of the first roller 511. The diameter of the second tapered portion 5123 decreases toward the side opposite the large diameter portion 5121 in the Y-axis direction (toward the positive Y-axis direction). The connecting portion 5122 connects the large diameter portion 5121 and the second tapered portion 5123. The connecting portion 5122 forms a gap V between the first tapered portion 5112 of the first roller 511 and the second tapered portion 5123 of the second roller 512.

[0052] The length L1 (see FIG. 6) of the gap V in a direction perpendicular to the surface S5112 of the first tapered region 5112 is longer than twice the thickness L11 (see FIG. 3) of the laminate film. The length L1 is the length (hereinafter also referred to as the "restriction length") over which the second tapered region 5123 restricts the opening of the folded region R11B10. The restriction length is preferably four times or less the thickness L11 of the laminate film. The restriction length may be four times the thickness L11 or may be three times the thickness L11.

[0053] In the present embodiment, the angle θ5112 and the angle θ5123 are the same. Specifically, the angles θ5112 and θ5123 are eighth angles. The angle θ5112 indicates the angle between the main surface S12 of the electrode body 12 and the first tapered portion 5112 when viewed from the X-axis direction. The angle θ5123 indicates the angle between the main surface S12 of the electrode body 12 and the second tapered portion 5123 when viewed from the X-axis direction. The bending angle θA can be adjusted by the angle θ5112.

[0054] (1.5.2) A pair of folding rollers The pair of folding rollers 52 changes the bending angle θA from the eighth angle to a ninth angle (for example, 60°). The pair of folding rollers 52 is similar to the pair of folding rollers 51 except that the angle θ5112 and the angle θ5123 are each the ninth angle.

[0055] (1.5.3) A pair of folding rollers The pair of folding rollers 53 sets the bending angle θA to a ninth angle to a tenth angle (for example, 85°). The pair of folding rollers 53 is similar to the pair of folding rollers 51 except that the angle θ5112 and the angle θ5123 are each the tenth angle.

[0056] (1.5.4) A pair of folding rollers The pair of folding rollers 54 changes the bending angle θA from the tenth angle to an eleventh angle (for example, 90°). The pair of folding rollers 54 is similar to the pair of folding rollers 51 except that the angle θ5112 and the angle θ5123 are each the tenth angle.

[0057] (2) The manufacturing method of a laminated battery is as follows: The laminated battery manufacturing method according to this embodiment is a method for manufacturing a battery 10 (i.e., a laminated battery) from an unfinished battery 10a (not shown) using a folding device 1. The manufacturing method includes a preparation step, a first folding step, and a second folding step. The preparation step, first folding step, and second folding step are performed in this order.

[0058] (2.1) Unfinished battery The unfinished battery 10a is similar to the battery 10 except that the folding region R11B10 and the bent region R11B21 are not formed. The edge seal region R11B of the unfinished battery 10a extends along the positive direction of the Y axis.

[0059] (2.2) Preparation process In the preparation step, an unfinished battery 10a is prepared. In this embodiment, the unfinished battery 10a is fixed to a fixture 30. At least a portion of the edge seal region R11B of the unfinished battery 10a protrudes from the fixture 30. The preparation methods for the unfinished battery 10a and the fixture 30 are known methods. Hereinafter, the fixture 30 and the unfinished battery 10a fixed to the fixture 30 will also be referred to as a "battery with fixture."

[0060] (2.3) First folding process In the first folding step, the edge seal region R11B is sandwiched between folding roller groups 44 and folded using the base line F1 as the folding line. Specifically, the edge seal region R11B of the battery with fasteners moving in the conveyance direction D is sandwiched between the upstream roller group 40 to form the folding region R11B10. As a result, the unfinished battery 10a with fasteners becomes the unfinished battery 10b. The unfinished battery 10b is similar to the battery 10 except that the folding region R11B21 is not formed.

[0061] (2.4) Second folding process In the second folding process, the edge seal region R11B is sandwiched between a pair of folding rollers 51-54, and the edge seal region R11B is folded along the base line F2. Specifically, the edge seal region R11B of the battery with fixing device moving in the conveyance direction D is sandwiched between the downstream roller group 50 to form the folding region R11B21. As a result, the unfinished battery with fixing device 10b becomes the battery 10. The battery 10 is obtained by removing the fixing device 30 from the battery with fixing device.

[0062] (3) Effects As described with reference to Figures 1 to 6, the folding device 1 includes a folding roller group 44 and a pair of folding rollers 51. The folding roller group 44 is made up of a lower roller 441, an inner roller 442, and an outer roller 443. The pair of folding rollers 51 is made up of a first roller 511 and a second roller 512. As a result, the folding device 1 can fold the edge seal region R11B more precisely than a folding device that does not include at least one of the folding roller group 44 and the pair of folding rollers 51.

[0063] As described with reference to FIGS. 1 to 6, the edge seal region R11B has a folding region R11B10 and a non-folding region R11B20. The pair of folding rollers 51 are a pair of folding rollers that fold the non-folding region RB20 using the first base line F2 as a folding line. The second roller 512 is disposed on the folding region R11B10 side. The first roller 511 includes a small diameter region 5111 and a first tapered region 5112. The second roller 512 includes a large diameter region 5121, a connecting region 5122, and a second tapered region 5123. The connecting region 5122 forms a gap V between the first tapered region 5112 and the second tapered region 5123. The length L1 of the gap V is longer than twice the thickness L11 of the laminate film and is a regulated length. As a result, the portion of the edge seal region R11B within the gap V is less likely to come into contact with the pair of folding rollers 51 than when the length L1 is equal to or less than twice the thickness L11 of the laminate film. Therefore, damage to the edge seal region R11B due to friction with the pair of folding rollers 51 is less likely to occur. The length L1 is a regulated length. This prevents the portion of the non-folding region R11B20 within the gap V from displacing toward the tapered region 5123 of the second roller 512. In addition, opening of the folding region R11B10 due to springback is prevented. As a result, the folding device 1 can fold the edge seal region R11B more precisely.

[0064] As described with reference to FIGS. 1 to 6, in the folding device 1, the restricted length is preferably four times or less the thickness L11 of the laminate film. This allows the folding device 1 to fold the edge seal region R11B more reliably and precisely than when the regulated length is more than four times the thickness L11 of the laminate film.

[0065] As described with reference to Figures 1 to 6, in the bending device 1, the interval LA (see Figure 4) is 1.0 to 3.5 times the length L (see Figure 5), and the interval LB (see Figure 4) is 0.4 to 1.2 times the length L. As a result, the base line F1, which is the folding line, is formed along the X-axis direction. As a result, the folding device 1 can fold the edge seal region R11B more precisely.

[0066] The relationship between the interval LA and the interval LB will be explained below. The present inventors have experimentally confirmed the relationship between the interval LA and the interval LB for forming the base line F2 along the X-axis direction. Specifically, the present inventors set the intervals LA and LB of the folding roller group 44 to the values ​​shown in Table 1. The folding roller group 44, which moves relative to the fixture 30 along the X-axis direction, sandwiched the edge seal region R11B that protruded from the fixture 30, forming the folding region R11B21. The resulting baseline F2 was visually observed. Based on the observation results of the baseline F2, it was evaluated according to the following evaluation criteria as to whether the baseline F2 was formed as intended (along the X-axis direction). The evaluation results are shown in Table 1. In Table 1, for example, "1.8L" indicates a length that is 1.8 times the length L.

[0067] <Evaluation criteria> "A": The angle formed between the direction in which the base line F2 extends and the X-axis direction was 0°. "B": The angle formed between the direction in which the base line F2 extends and the X-axis direction was not 0°. An acceptable rating is "A".

[0068] [Table 1]

[0069] As shown in Table 1, when the distance LA was 1.0L, 1.8L, 2.6L, or 3.5L and the distance LB was 0.4L or 1.2L, the evaluation result was "A." Otherwise, the evaluation result was "B." In the folding device 1, the distance LA was 1.0 to 3.5 times the length L, and the distance LB was 0.4 to 1.2 times the length L. As a result, it was experimentally confirmed that the folding device 1 is "a folding device that can fold the edge seal portion more precisely."

[0070] 1 to 6, the method for manufacturing a laminated battery of this embodiment uses a folding apparatus 1. The manufacturing method includes a first folding step and a second folding step. As a result, the laminated battery manufacturing method of this embodiment can manufacture a battery 10 in which the edge seal region R11B is folded as intended.

[0071] (4) Variations In this embodiment, the folding device 1 includes a conveying section 20, a fixing device 30, an upstream roller group 40, and a downstream roller group 50, but the present disclosure is not limited to this. The folding device of the present disclosure does not need to include other components of the folding device 1 (such as the fixing device 30 and the pair of rollers 41 to 43) as long as it includes a pair of folding rollers 51 and a folding roller group 44.

[0072] In this embodiment, the length L1 of the gap V is longer than twice the thickness L11 of the laminate film and is a restricted length, but the present disclosure is not limited to this. The length L1 of the gap V does not have to be longer than twice the thickness L11 of the laminate film and be a restricted length. In this embodiment, the first roller 511 includes the small diameter portion 5111 and the first tapered portion 5112, but the present disclosure is not limited thereto. The first roller 511 does not necessarily have to include at least one of the small diameter portion 5111 and the first tapered portion 5112. In this embodiment, the second roller 512 includes the large diameter portion 5121, the connecting portion 5122, and the second tapered portion 5123, but the present disclosure is not limited thereto. The second roller 512 does not necessarily have to include at least one of the large diameter portion 5121, the connecting portion 5122, and the second tapered portion 5123.

[0073] In this embodiment, the interval LA is 1.0 to 3.5 times the length L, and the interval LB is 0.4 to 1.2 times the length L, but the present disclosure is not limited to this. The interval LA does not have to be 1.0 to 3.5 times the length L. The interval LB does not have to be 0.4 to 1.2 times the length L.

[0074] In the first folding step of this embodiment, the upstream roller group 40 is used, but the present disclosure is not limited to this. In the first folding step, only the folding roller group 44 may be used. In the second bending step of this embodiment, the downstream roller group 50 is used, but the present disclosure is not limited to this. In the second bending step, any one of the pairs of bending rollers 51 to 54 may be used.

[0075] In this embodiment, the folding site R11B10 is folded once, but the present disclosure is not limited thereto. The folding site R11B10 may be folded at least twice.

[0076] In this embodiment, the angle θ5112 and the angle θ5123 are the same, but the present disclosure is not limited to this. The angle θ5112 and the angle θ5123 may be different.

[0077] In this embodiment, the inner roller 442 presses a portion of the non-folding region R11B20 (i.e., a portion near the base line F1) from the positive direction of the Z axis, but the present disclosure is not limited to this. The inner roller 442 may press the entire non-folding region R11B20 (i.e., a portion near the base line F1) from the positive direction of the Z axis. [Explanation of symbols]

[0078] 1: bending device, 10: laminated battery, 11: exterior body, 12: electrode body, 13: terminal, 20: conveying section, 30: fixture, 40: upstream roller group, 41-43, 45-47: pair of rollers, 44: bending roller group, 441: lower roller, 442: inner roller, 443: outer roller, 50: downstream roller group, 51-54: pair of bending rollers, 511: first roller, 512: second roller, V: gap, L: length of bending portion, L1: regulated length, L11: thickness of laminate film

Claims

1. A folding device for folding an edge seal portion extending in a first direction of a laminated battery, The edge seal portion is formed by welding the edges of the laminate film together, The folding device includes a folding roller group and a pair of folding rollers, The bending roller group a lower roller that supports a first portion of the edge seal portion from below; an inner roller that presses at least a part of the first portion from above; an outer roller that presses a second portion of the edge seal portion that is closer to the tip end than the first portion toward the inner roller to form the bent portion; The pair of folding rollers comprises a first roller and a second roller whose rotation axes are parallel to each other in the first direction.

2. The edge seal region has a folded region that is folded at least once and a non-folded region, the pair of folding rollers are a pair of folding rollers that fold the non-folding portion with the first base line as a folding line, the first base line is located closer to a base of the edge seal region than an overlapping region of the non-folded region that overlaps with the folded region, The second roller is disposed on the folding portion side, the first roller includes a small diameter portion and a first tapered portion connected to the small diameter portion and having a diameter increasing toward a side opposite to the small diameter portion in the first direction, The second roller is a large diameter portion facing the small diameter portion and forming the first base line; a second tapered portion that faces the first tapered portion and has a diameter that decreases toward a side opposite to the large diameter portion in the first direction; a connecting portion that connects the large diameter portion and the second tapered portion and forms a gap between the first tapered portion and the second tapered portion; Including, 2. The folding device of claim 1, wherein the length of the gap in a direction perpendicular to the surface of the first tapered portion is longer than twice the thickness of the laminate film, and the second tapered portion is of a length that restricts the opening of the folding portion.

3. The folding device according to claim 2 , wherein the length of the second tapered portion that restricts the opening of the folding portion is four times or less the thickness of the laminate film.

4. a distance in a second direction between the position of the rotation shaft of the outer roller and the position of the rotation shaft of the lower roller is 1.0 to 3.5 times the length L; a distance in the second direction between the position of the rotation shaft of the outer roller and the position of the rotation shaft of the inner roller is 0.4 to 1.2 times the length L; the second direction is a direction perpendicular to the first direction, The bending device according to claim 1 , wherein the length L indicates a length of the bending portion as viewed from the second direction.

5. A method for manufacturing a laminated battery using the folding device according to any one of claims 1 to 4, sandwiching the edge seal region between the folding roller group and folding the edge seal region along the second base line; and sandwiching the edge seal area between the pair of folding rollers and folding the edge seal area along a first base line located on the base side of the edge seal area relative to the second base line.

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