JP2019129126A - Method for manufacturing battery - Google Patents

Abstract

To provide a method for manufacturing a battery, capable of achieving excellent welding between an exterior can and a sealing plate.SOLUTION: The method for manufacturing a battery, capable of sealing the opening of an exterior can for holding an electrolyte solution by a sealing plate comprises the steps of: fitting the sealing plate in the inner wall of the opening of the exterior can having the opening; irradiating the exterior can or the sealing plate with a first laser; and irradiating a region including a boundary contacted by the exterior can and the sealing plate with a second laser.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a battery manufacturing method.

  In the method of manufacturing a battery in which the opening of the outer can is sealed with a sealing plate using a laser beam, when the electrolytic solution is poured into the outer can, the electrolytic solution adheres to the opening. To solve this problem, the electrolytic solution is removed by irradiating the first laser beam to the opening of the outer can or the vicinity of the opening, and then the outer can and the sealing plate are welded by irradiating the second laser beam. There is a known method (see, for example, Patent Document 1).

JP 2000-21437 A

  In recent years, in a method of manufacturing a battery, it is required to realize good welding of an outer can and a sealing plate.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a battery manufacturing method capable of realizing good welding between an outer can and a sealing plate.

In order to achieve the above object, a method of manufacturing a battery of one aspect of the present invention is
A method of manufacturing a battery, comprising: sealing an opening of an outer case that holds an electrolytic solution with a sealing plate,
Fitting the sealing plate to the inner wall of the opening of the outer can provided with the opening;
Applying a first laser to the outer can or the sealing plate;
Applying a second laser to a region including a boundary where the outer can and the sealing plate contact each other;
including.

  As described above, according to the battery manufacturing method of the present invention, it is possible to realize good welding between the outer can and the sealing plate.

Exemplary cross-sectional schematic diagram of a cylindrical battery according to Embodiment 1 of the present invention. Exemplary flow chart of manufacturing method of cylindrical battery according to Embodiment 1 of the present invention An exemplary schematic diagram of a laser welding process in Embodiment 1 of the present invention An exemplary schematic diagram of a laser welding process in Embodiment 1 of the present invention Exemplary schematic diagram of laser welding process in Embodiment 1 of the present invention Exemplary schematic diagram of laser welding process in Embodiment 1 of the present invention Exemplary schematic diagram of the mechanism of occurrence of defective welds Exemplary schematic diagram of the mechanism of occurrence of defective welds Exemplary schematic diagram of the mechanism of occurrence of defective welds Exemplary schematic diagram of the mechanism of occurrence of defective welds

(Background to the present invention)
In recent years, a battery manufacturing method has been developed in which an electrolytic solution attached to an opening of an outer can is removed using a laser. In such a battery manufacturing method, as shown in FIG. 4A, in order to remove the electrolytic solution 180 adhering to the bonding interface 123 between the opening 121 of the outer can 102 and the outer edge 137 of the sealing plate 103, the bonding is performed. The interface 123 is irradiated with the first laser 141.

  When the first laser 141 is irradiated to the bonding interface 123, the opening end surface 122 of the outer can 102 and the end surface 138 of the sealing plate 103 are heated. Thereby, the electrolytic solution 180 is vaporized and removed.

  The opening edge portion 124 of the outer can 102 and / or the edge portion 139 of the sealing plate 103 is a portion that is easily melted. When the bonding interface 123 is irradiated with the first laser 141, as shown in FIG. 4B, the opening edge portion 124 of the outer can 102 and / or the edge portion 139 of the sealing plate 103 partially melts, and the first melting portion 151 It is formed. That is, when the first laser 141 is irradiated to the bonding interface 123, the opening edge portion 124 of the outer can 102 and / or the edge portion 139 of the sealing plate 103 is melted and deformed to form the first melting portion 151. Therefore, a gap 161 may occur between the outer can 102 and the sealing plate 103. Alternatively, the sealing plate 103 may float from the outer can 102 in some cases.

  When the gap 161 is formed between the outer can 102 and the sealing plate 103, as shown in FIG. 4C, when the second laser 142 is irradiated, the gap 161 is formed by the molten metal of the outer can 102 and the sealing plate 103. May not be filled. In this case, as shown in FIG. 4D, a poorly welded portion 162 formed in a pinhole shape is generated between the outer can 102 and the sealing plate 103.

  Further, when the sealing plate 103 floats, a step is generated between the opening end surface 122 of the opening 121 of the outer can 102 and the end surface 138 of the outer edge 137 of the sealing plate 103. When the step is generated, the metal of the outer can 102 and the sealing plate 103 melted by the irradiation of the second laser 142 may not be integrated, resulting in poor welding.

  As described above, in the battery manufacturing method in which the electrolytic solution 180 attached to the bonding interface 123 between the outer can 102 and the sealing plate 103 is removed by laser irradiation, poor welding may occur. For this reason, since favorable welding with the exterior can 102 and the sealing board 103 cannot be implement | achieved and appropriate sealing cannot be obtained, there exists a subject that a battery characteristic cannot be ensured.

  Therefore, the inventors of the present invention conducted earnest research and reached the following invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1
FIG. 1 is a schematic cross-sectional view of a cylindrical battery 1 according to Embodiment 1 of the present invention. The X and Y directions in FIG. 1 indicate the lateral direction and the longitudinal direction of the cylindrical battery 1, respectively.

  As shown in FIG. 1, the cylindrical battery 1 includes a bottomed cylindrical outer can 2 and a sealing plate 3 welded to the outer can 2.

  The outer can 2 is, for example, a cylindrical case formed of metal such as SUS. The outer can 2 is formed in a bottomed cylindrical shape having an opening 20 at one end. The outer can 2 accommodates therein an electrode assembly 35 including a positive electrode, a separator, and a negative electrode, and an electrolytic solution 36.

  The sealing plate 3 includes a disk-shaped flange 31, a positive electrode terminal 32 disposed in a hole formed in the center of the flange 31, and a gasket 33 disposed between the flange 31 and the positive electrode terminal 32. .

  The flange 31 is formed of metal such as SUS. The flange 31 has a rising portion 37 projecting on the upper surface side of the sealing plate 3. The rising portion 37 extends in the longitudinal direction (Y direction) of the cylindrical battery 1 and is formed in an annular shape along the outer edge of the flange 31. The positive electrode terminal 32 is connected to the electrode group 35 via the positive electrode lead 34. The gasket 33 functions as an insulating member that insulates the flange 31 and the positive electrode terminal 32. The gasket 33 is made of, for example, a resin or the like.

  In the cylindrical battery 1, the sealing plate 3 is fitted to the inner wall of the opening 21 of the outer can 2. Specifically, in the cylindrical battery 1, the rising portion 37 that is formed on the outer edge of the sealing plate 3 and extends to the upper surface side of the sealing plate 3 is brought into contact with the inner wall of the opening 21 of the outer can 2. The plate 3 is fitted to the outer can 2.

  In the cylindrical battery 1, sealing is performed on the inner periphery of the outer can 2 in a state in which the opening end surface 22 of the opening 21 of the outer can 2 and the end surface 38 of the rising portion 37 of the sealing plate 3 are aligned. The rising portion 37 of the plate 3 is fitted.

  In the cylindrical battery 1, the end portion of the opening portion 21 of the outer can 2 and the end portion of the rising portion 37 of the sealing plate 3 are welded to form a melting portion 52. Thereby, the opening 20 of the outer can 2 is sealed by the sealing plate 3.

  In Embodiment 1, by irradiating the opening end surface 22 of the outer can 2 and the end surface 38 of the rising portion 37 of the sealing plate 3 with the laser, the end portion of the opening 21 of the outer can 2 and the rising portion of the sealing plate 3 are irradiated. Welded to the end of 37. In other words, the end portion of the opening 21 of the outer can 2 and the end portion of the rising portion 37 of the sealing plate 3 are melted by a laser to form the melting portion 52. The end of the opening 21 of the outer can 2 and the end of the rising portion 37 of the sealing plate 3 are connected by the melting portion 52, and the opening 20 of the outer can 2 is sealed by the sealing plate 3.

  A method for manufacturing cylindrical battery 1 according to Embodiment 1 will be described. FIG. 2 shows an exemplary flowchart of a method for manufacturing the cylindrical battery 1. As shown in FIG. 2, the manufacturing method of the cylindrical battery 1 includes a step ST1 for fitting the sealing plate 3 to the outer can 2, a step ST2 for irradiating the first laser, and a step ST3 for irradiating the second laser. .

  In step ST1, the sealing plate 3 is fitted to the inner wall of the opening 21 of the outer can 2 in which the opening 20 is provided. In the first embodiment, the rising portion 37 of the sealing plate 3 is fitted to the inner periphery of the opening 21 of the outer can 2 containing the electrode group 35 including the positive electrode, the separator and the negative electrode and the electrolytic solution 36 in the outer can 2. .

  Further, in step ST1, the inner periphery of the opening 21 of the outer can 2 is sealed so that the opening end face 22 of the opening 21 of the outer can 2 and the end surface 38 of the rising portion 37 of the sealing plate 3 are flush with each other. The rising portion 37 of the plate 3 is fitted.

  Steps ST2 and ST3 will be described using FIGS. 3A to 3D. 3A to 3D are schematic cross-sectional views of a laser welding process for sealing the outer can 2 and the sealing plate 3 in the first embodiment. 3A to 3D are enlarged views of a part of the cylindrical battery 1 of FIG.

  As shown in FIG. 3A, the electrolytic solution 80 is attached to the bonding interface (boundary) 23 where the outer can 2 and the sealing plate 3 are in contact. In step ST2, the first laser 41 is irradiated to the outer can 2 or the sealing plate 3. Thereby, the electrolytic solution 80 is vaporized and removed.

  Specifically, in step ST <b> 2, the first laser 41 is applied to the opening end surface 22 of the outer can 2 or the end surface 38 of the rising portion 37 of the sealing plate 3. In the first embodiment, the first laser 41 is irradiated on the end surface 38 of the rising portion 37 of the sealing plate 3 in step ST2.

  In step ST <b> 2, the first laser 41 is irradiated toward the end surface 38 from a direction (Y direction) perpendicular to the end surface 38 of the rising portion 37 of the sealing plate 3. Thereby, the end face 38 of the rising portion 37 of the sealing plate 3 is heated. As a result, as shown in FIG. 3B, the electrolyte solution 80 can be vaporized and removed by the heat generated on the end face 38 of the rising portion 37.

  In step ST3, as shown to FIG. 3C, the 2nd laser 42 is irradiated to the area | region 25 containing the joining interface (boundary) 23 which the armored can 2 and the sealing board 3 contact | connect. Thereby, the outer can 2 and the sealing plate 3 are welded.

  In the first embodiment, the second laser 42 is applied across the opening end surface 22 of the opening 21 of the outer can 2 and the end surface 38 of the rising portion 37 of the sealing plate 3. Specifically, the second laser 42 is directed to the bonding interface 23 from the direction (Y direction) perpendicular to the opening end face 22 of the opening 21 of the outer can 2 and the end face 38 of the rising portion 37 of the sealing plate 3. It is irradiated.

  Thereby, as shown in FIG. 3D, the end portion of the opening 21 of the outer can 2 and the end portion of the rising portion 37 of the sealing plate 3 are partially melted to form a melting portion 52. The melting part 52 connects the end of the opening 21 of the outer can 2 and the end of the rising part 37 of the sealing plate 3. As a result, the external can 2 and the sealing plate 3 can be integrated and sealed.

  The second laser 42 is a laser beam having a power density higher than that of the first laser 41.

  As described above, by performing steps ST1 to ST3, the cylindrical battery 1 can be manufactured.

  Next, the first laser 41 and the second laser 42 will be described in detail.

  In the first embodiment, as an example, both the first laser 41 and the second laser 42 are single mode fiber lasers (3 kW single mode YLS-3000-SM manufactured by IPG). The laser beam emitted from the fiber is collimated by a collimator lens (f 355 mm), and the laser beam collected by the fθ lens (255 mm) is scanned by using a galvano mirror. Thereby, irradiation is performed on a predetermined position of the object to be processed.

  In the first embodiment, the second laser 42 has a laser spot diameter that is about 100 μm larger than the sum of the width of the opening end face 22 of the opening 21 of the outer can 2 and the width of the end face 38 of the rising portion 37 of the sealing plate 3. Thus, the distance from the fθ lens is adjusted. Further, the distance from the fθ lens is adjusted so that the first laser 41 has a diameter smaller than the laser spot diameter of the second laser 42.

  In the first embodiment, in the combination of the collimating lens and the fθ lens, a desired laser spot is obtained by setting the position away from the focal position. However, a combination of lens focal lengths may be chosen to achieve the desired laser spot diameter at the focal position. By performing laser irradiation at the focal position, for example, when an observation optical system such as a coaxial camera is provided, the irradiation position can be observed in advance. The laser oscillator may be a multimode fiber laser.

  In the first embodiment, a value calculated from a fiber diameter, a collimating lens, and an fθ lens geometrically optically is defined as a spot diameter.

  In the first embodiment, in step ST <b> 2, the first laser 41 is applied to the central portion 74 of the end surface 38 of the rising portion 37 of the sealing plate 3. The central portion 74 means a central portion on the end face 38 at an equal distance from the outer wall and the inner wall of the rising portion 37 of the sealing plate 3 when the cylindrical battery 1 is viewed from above.

  In step ST 2, the first laser 41 is scanned so that the center 71 of the laser spot of the first laser 41 passes through the central portion 74 of the end face 38 of the rising portion 37 of the sealing plate 3.

  As described above, the center 71 of the laser spot of the first laser 41 passes through the central portion 74 of the end face 38 of the rising portion 37 of the sealing plate 3, thereby sealing the region of the first laser 41 where the intensity of the laser beam is high. The end surface 38 of the rising portion 37 of the plate 3 can be irradiated. Thereby, since the end surface 38 of the rising portion 37 of the sealing plate 3 can be efficiently heated, the electrolytic solution 80 attached to the bonding interface 23 can be efficiently removed.

In the first embodiment, when the first laser 41 is irradiated to the central portion 74 of the end surface 38 of the rising portion 37 of the sealing plate 3, the laser spot diameter of the first laser 41 is set to the rising portion 37 of the sealing plate 3. The width of the end face 38 (the length in the X direction), that is, the same size as the thickness of the rising portion 37 of the sealing plate 3 is preferable. Thereby, it is suppressed that laser light with high power density (1 / e ² (e represents a natural logarithm) or more) is irradiated to the edge 39 of the sealing plate 3 and / or the opening edge 24 of the outer can 2. can do. As a result, the first laser 41 can suppress melting of the opening edge portion 24 of the outer can 2 and / or the edge portion 39 of the sealing plate 3.

  In the first embodiment, the example in which the first laser 41 is irradiated to the central portion 74 of the end surface 38 of the rising portion 37 of the sealing plate 3 has been described, but the present invention is not limited to this. For example, you may irradiate the 1st laser 41 to the center part 73 (refer FIG. 3A) of the opening end surface 22 of the opening part 21 of the exterior can 2. FIG. The central portion 73 of the opening end surface 22 of the opening 21 of the outer can 2 is the center on the opening end surface 22 at the same distance from the outer wall and inner wall of the outer can 2 when the cylindrical battery 1 is viewed from above. Means the part.

When the first laser 41 is irradiated to the central portion 73 of the opening end surface 22 of the opening 21 of the outer can 2, the size of the laser spot diameter of the first laser 41 is the width of the opening end surface 22 of the outer can 2 (X direction). Or less than 1.5 times the thickness of the side wall of the outer can 2). Thereby, it is possible to suppress irradiation of laser light having a high power density (1 / e ² or more) to the edge 39 of the rising portion 37 of the sealing plate 3 and / or the opening edge 24 of the outer can 2. . As a result, it is possible to prevent the opening edge portion 24 of the outer can 2 and / or the edge portion 39 of the sealing plate 3 from being melted by the first laser 41. Moreover, since the opening end surface 22 of the outer can 2 can be efficiently heated, the electrolytic solution 80 adhering to the bonding interface 23 can be efficiently removed.

  Thus, when the first laser 41 is irradiated to the opening end face 22 of the outer can 2 in the step ST2 of irradiating the first laser 41, the first laser 41 is directed to the central portion 73 of the opening end face 22 of the outer can 2. It may be irradiated.

  When the first laser 41 is irradiated to the central portion 73 of the opening end surface 22 of the outer can 2, the size of the laser spot diameter of the first laser 41 is the width of the opening end surface 22 of the outer can 2 (length in the X direction). That is, the thickness of the side wall of the outer can 2 is preferably 0.5 times or more. Thereby, it is possible to irradiate the end surface 38 of the rising portion 37 of the sealing plate 3 with sufficient laser power, and it is possible to effectively remove the electrolytic solution 80 attached to the bonding interface 23.

  The center 71 of the laser spot of the first laser 41 is 1/3 or more of the laser spot diameter of the first laser 41 in the width direction of the opening end face 22 of the outer can 2 from the bonding interface 23 of the outer can 2 and the sealing plate 3 It is preferable that the distance is 2/3 or less.

Laser power with high power density (1 / e ² or more) is obtained by setting the distance between the center 71 of the laser spot of the first laser 41 and the bonding interface 23 to 1/3 or more of the laser spot diameter of the first laser 41. Can be suppressed from being irradiated to the bonding interface 23. That is, it is possible to suppress the irradiation of the region where the intensity of the laser beam of the first laser 41 is strong to the bonding interface 23. As a result, it is possible to suppress melting of the opening edge portion 24 of the outer can 2 and / or the edge portion 39 of the rising portion 37 of the sealing plate 3, which causes poor bonding.

Further, by setting the distance between the center 71 of the laser spot of the first laser 41 and the bonding interface 23 to 2/3 or less of the laser spot diameter of the first laser 41, the power density is high (1 / e ² or more). Laser light can be irradiated to the end face 38 of the rising portion 37 of the sealing plate 3. Thereby, the joining interface 23 between the outer can 2 and the sealing plate 3 can be effectively heated, and the electrolytic solution 80 attached to the joining interface 23 can be removed.

  As described above, when the first laser 41 is irradiated to the opening end face 22 of the outer can 2 in step ST2 of irradiating the first laser 41, the laser spot diameter of the first laser 41 is the same as that of the opening end 22 of the outer can 2. It may be 1/3 or more and 3/2 or less of the width. In this case, the center 71 of the laser spot of the first laser 41 is a distance of 1/3 or more and 2/3 or less of the laser spot diameter of the first laser 41 in the width direction (X direction) of the opening end face 22 from the bonding interface 23. May be separated.

  Further, in step ST <b> 2 in which the first laser 41 is irradiated, the end surface 38 of the rising portion 37 of the sealing plate 3 may be irradiated with the first laser 41. The laser spot diameter of the first laser 41 may be 1/3 or more and 3/2 or less of the width of the end face 38 of the rising portion 37 of the sealing plate 3. In this case, the center 71 of the laser spot of the first laser 41 is separated from the bonding interface 23 in the width direction (X direction) of the end surface 38 of the rising portion 37 by a distance of 1/3 or more and 2/3 or less of the laser spot diameter. May be.

  In step ST3 of irradiating the second laser 42, the second laser 42 is formed by the joint interface 23 of the outer can 2 and the sealing plate 3 or the open end face 22 of the outer can 2 and the end face 38 of the rising portion 37 of the sealing plate 3 You may irradiate the center part 75 of the surface formed.

  The central portion 75 is formed from the outer wall of the outer can 2 and the inner wall of the rising portion 37 of the sealing plate 3 on the surface formed by the opening end surface 22 of the outer can 2 and the end surface 38 of the rising portion 37 of the sealing plate 3. It means a central part at equal distance from each other. In other words, the portion located in the center of the total width of the total width of the width (length in the X direction) of the opening end surface 22 of the outer can 2 and the width (length in the X direction) of the end surface 38 of the rising portion 37 of the sealing plate 3. Means

  By irradiating the bonding interface 23 between the outer can 2 and the sealing plate 3 or the central portion 75 with the second laser 42, the sealing plate 3 and the outer can 2 are uniformly melted to form a good melted portion 52. Can do. Thereby, good welding of the outer can 2 and the sealing plate 3 is possible.

  The center 72 of the laser spot of the second laser 42 is a plane formed by the bonding interface 23 of the outer can 2 and the sealing plate 3 or the open end face 22 of the outer can 2 and the end face 38 of the rising portion 37 of the sealing plate 3 You may be located in the center part 75. FIG.

  By scanning the second laser 42 so that the laser light is focused on the bonding interface 23 of the outer can 2 and the sealing plate 3, the deepest region of the melting portion 52 is along the trajectory of the second laser 42. It is formed. For this reason, high sealing pressure strength can be ensured.

  Further, when the thickness of the outer can 2 and the sealing plate 3 is different, the laser beam is focused on the central portion 75 of the full width obtained by totaling the width of the opening end face 22 of the outer can 2 and the width of the end face 38 of the sealing plate 3. The second laser 42 is scanned so that the bonding interface 23 is included in the laser spot. As a result, the entire width including the width of the opening end surface 22 of the outer can 2 and the end surface 38 of the sealing plate 3 can be uniformly melted, and a good melting portion 52 can be formed.

  In the first embodiment, the laser spot diameter of the second laser 42 is about 100 μm larger than the sum of the width of the opening end surface 22 of the outer can 2 and the width of the end surface 38 of the rising portion 37 of the sealing plate 3. With such a configuration, variations in the irradiation position of the second laser 42, variations in the outer shape of the outer can 2 and the like can be tolerated, and welding of the outer can 2 and the sealing plate 3 can be performed with high yield.

  When the laser spot diameter of the second laser 42 and the laser spot diameter of the first laser 41 are changed, the adjustment of the spot diameter is performed by adjusting the working distance from the condenser lens to the processing point and / or the processing machine. Control can be performed by adjusting the arrangement of the optical elements of the provided optical system.

  In the first embodiment, the power density of the first laser 41 is smaller than the power density of the second laser 42. With such a configuration, melting of the opening edge portion 24 of the outer can 2 and / or the edge portion 39 of the sealing plate 3 by the first laser 41 can be suppressed. In addition, it is preferable that the first laser 41 has a power density of 1/2 or more and 1/10 or less compared to the second laser 42. Thereby, it can suppress that a clearance gap generate | occur | produces in the joining interface 23 of the armored can 2 and the sealing board 3, and can weld the armored can 2 and the sealing board 3 with a high yield.

  The adjustment of the power density of the second laser 42 and the first laser 41 may be controlled by the scanning speed, the spot diameter, and the laser power, and may be controlled by a combination thereof, and optimal control is performed depending on the shape of the processed part. Just do it.

In the first embodiment, the laser beam used for the second laser 42 irradiates a continuous wave, and seam welding may be performed. The power density of the second laser 42 is about 1.4 kW / mm ² , and the scanning speed is about 100 mm / s. Thereby, the fusion | melting part 52 formed by irradiation of the 2nd laser 42 is formed to the depth of about 200-300 micrometers.

  In the first embodiment, the scanning speed of the first laser 41 and the second laser 42 is about 100 mm / s, but the scanning speed may be lower. By slowing down the scanning speed, a stable molten metal flow can be formed in the laser irradiation portion, and stable welding becomes possible. In the case of reducing the scanning speed, adjustment may be made to conditions under which appropriate melting can be obtained, such as lowering the power density of laser light. For example, since the heat flow to areas other than the melted area is increased, for example, the temperature of the area other than the melted area, such as the gasket 33, is increased.

  Also, the scanning speed of the first laser 41 and the second laser 42 may be faster than 100 mm / s. The power density of the first laser 41 and the second laser 42 may be increased and adjusted to the conditions for obtaining appropriate melting. By increasing the scanning speed, it is possible to suppress the outflow of heat to parts other than the laser irradiation part, and to prevent temperature rises other than the melting part 52.

  The depth of the fusion zone 52 may be adjusted according to the required sealing strength. In order to increase the sealing strength, it is sufficient to secure a deeper penetration depth.By increasing the power input per unit time by increasing the power density and slowing the scanning speed, the deep penetration and melting zone can be increased. It can be formed.

  As described above, in the manufacturing method of the cylindrical battery 1, the first laser 41 is irradiated to the outer can 2 or the sealing plate 3 in welding the opening 21 of the outer can 2 and the sealing plate 3 using a laser. ing. Thus, by efficiently heating the outer can 2 or the sealing plate 3, the electrolytic solution 80 attached to the bonding interface 23 between the outer can 2 and the sealing plate 3 can be vaporized and removed.

  Further, according to the method for manufacturing the cylindrical battery 1, the first laser 41 is not directly applied to the opening edge portion 24 of the outer can 2 and the edge portion 39 of the rising portion 37 of the sealing plate 3. The floating of the sealing plate 3 can be suppressed.

  Further, in the method of manufacturing the cylindrical battery 1, the second laser 42 is used at the bonding interface 23 between the outer can 2 and the sealing plate 3, or the open end face 22 of the outer can 2 and the end face 38 of the rising portion 37 of the sealing plate 3. The central portion 75 of the entire width is irradiated. Thereby, the outer can 2 and the sealing plate 3 can be welded well, and the occurrence of welding defects can be suppressed. As a result, the external can 2 and the sealing plate 3 can be properly sealed to ensure battery characteristics.

  In the first embodiment, the example in which the sealing plate 3 has the rising portion 37 has been described, but the present invention is not limited to this. The sealing plate 3 may not have the rising portion 37. In this case, the sealing plate 3 is fitted to the outer can 2 by the outer edge of the flange 31 coming into contact with the inner wall of the opening 21 of the outer can 2. Thereby, the sealing board 3 can be made into a simple structure.

  In Embodiment 1, the example in which the first laser 41 is applied to the opening end surface 22 of the opening 21 of the outer can 2 or the end surface 38 of the rising portion 37 of the sealing plate 3 has been described, but the present invention is not limited to this. The first laser 41 may be irradiated to the outer can 2 or the sealing plate 3. It is only necessary to heat the outer can 2 or the sealing plate 3 by irradiating the first laser 41. The first laser 41 may be applied to the outer wall of the opening 21 of the outer can 2 or may be applied to the inner wall of the rising portion 37 of the sealing plate 3.

  While the invention has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

  The present invention can be applied to the production of sealed batteries such as lithium primary batteries, lithium secondary batteries, nickel cadmium storage batteries, nickel hydride storage batteries. That is, after injecting an electrode group consisting of a positive electrode, a separator, a negative electrode, and the like and an electrolytic solution into a metal outer can formed into a bottomed cylindrical shape, the sealing plate is sealed in the opening of the outer can and the outer can The present invention can be applied when sealing.

Reference Signs List 1 cylindrical battery 2 outer package can 3 sealing plate 20 opening 21 opening 22 opening end surface 23 bonding interface (boundary)
24 Opening edge portion 25 Region 31 Flange 32 Positive electrode terminal 33 Gasket 34 Positive electrode lead 35 Electrode group 36 Electrolytic solution 37 Rising portion 38 End surface 39 Edge portion 41 First laser 42 Second laser 52 Melting portion 71 Center of laser spot of first laser 72 Center of Laser Spot of Second Laser 73 Center Part 74 Center Part 75 Center Part 80 Electrolyte 102 Exterior Can 103 Sealing Plate 121 Opening 122 Opening End Face 123 Bonding Interface (Boundary)
124 Open edge portion 137 Outer edge portion 138 End surface 139 Edge portion 141 First laser 142 Second laser 151 Melting portion 152 Melting portion 161 Clearance 162 Welding failure portion 180 Electrolytic solution

Claims (8)

A method of manufacturing a battery, comprising: sealing an opening of an outer case that holds an electrolytic solution with a sealing plate,
Fitting the sealing plate to the inner wall of the opening of the outer can provided with the opening;
Applying a first laser to the outer can or the sealing plate;
Applying a second laser to a region including a boundary where the outer can and the sealing plate contact each other;
A method for producing a battery, comprising: The sealing plate has a rising portion formed on the outer edge and extending to the upper surface side of the sealing plate,
The step of fitting the sealing plate includes fitting the rising portion of the sealing plate to the inner wall of the opening of the outer can where the opening is provided,
The step of irradiating the second laser irradiates the second laser across the opening end surface of the outer can and the end surface of the rising portion of the sealing plate.
The method for producing a battery according to claim 1.   The manufacturing of the battery according to claim 2, wherein the step of irradiating the first laser includes irradiating the first laser to the open end face of the outer can or the end face of the rising portion of the sealing plate. Method. The step of irradiating the first laser comprises:
When irradiating the opening end surface of the outer can with the first laser, irradiating the first laser to a central portion of the opening end surface of the outer can, and to the end surface of the rising portion of the sealing plate When irradiating 1 laser, irradiating the first laser to the central portion of the end surface of the rising portion of the sealing plate,
The manufacturing method of the battery of Claim 2 or 3 including B. In the step of irradiating the first laser,
When irradiating the first laser to the open end face of the outer can,
The laser spot diameter of the first laser is not less than 1/3 and not more than 3/2 of the width of the opening end surface of the outer can.
The center of the laser spot of the first laser is separated from the boundary by a distance of 1/3 or more and 2/3 or less of the laser spot diameter in the width direction of the opening end face.
When irradiating the first laser to the end face of the rising portion of the sealing plate,
The laser spot diameter of the first laser is 1/3 or more and 3/2 or less of the width of the end surface of the rising portion of the sealing plate,
The center of the laser spot of the first laser is separated from the boundary in the width direction of the end face of the rising portion by a distance of 1/3 or more and 2/3 or less of the laser spot diameter.
The manufacturing method of the battery of Claim 2 or 3.   The center of the laser spot of the second laser is located at the center of the plane formed by the boundary or the open end face of the outer can and the end face of the rising portion of the sealing plate. The method for producing a battery according to claim 5.   The method of manufacturing a battery according to claim 1, wherein the power density of the first laser is smaller than the power density of the second laser.   The battery manufacturing method according to claim 7, wherein the power density of the first laser is not less than ½ times and not more than 1/10 of the power density of the second laser.

Images