Power storage device and method for manufacturing power storage device

Abstract

This invention relates to an energy storage device and a method for manufacturing such a device, providing techniques to further improve the welding quality of a first conductive component and a second conductive component. In one embodiment of the energy storage device disclosed herein, the device includes an electrode body, a first conductive component, and a second conductive component. The first conductive component includes a through hole. The second conductive component includes a connecting portion and a converging portion. The connecting portion is inserted into the through hole. The converging portion is provided at the end of the connecting portion and is converging at the edge of the through hole of the first conductive component. A welding portion for welding the first conductive component and the second conductive component is provided in the converging portion. A gap exists between the first conductive component and the second conductive component closer to the inside of the welding portion. The welding portion provided in the converging portion has a first welding area and a second welding area with a welding depth smaller than the first welding area.

Description

Technical Field

[0001] This disclosure relates to energy storage devices and methods for manufacturing energy storage devices. Background Technology

[0002] Japanese Patent Application Publication No. 2017-10743 discloses a secondary battery comprising an electrode body, an outer casing, a sealing plate having terminal mounting holes, a current collector, and terminals inserted into the terminal mounting holes. The current collector has a through hole. A countersunk hole is formed around the through hole. The terminal is inserted into the through hole, and its front end is slotted within the countersunk hole. The front end of the slotted portion of the terminal is welded to the current collector. A groove is provided on the outer periphery of the countersunk hole in the current collector. The publication states that this configuration further improves the quality of the weld between the front end of the slotted portion of the terminal and the current collector, thereby enhancing reliability.

[0003] Japanese Patent Application Publication No. 2022-28968 discloses a secondary battery comprising an electrode body, an outer casing, a sealing plate having a terminal insertion hole, a terminal penetrating the terminal insertion hole, and a current collector having a terminal connection hole. The terminal is disposed within the terminal connection hole. The terminal connection hole has a first hole portion and a second hole portion connected to the first hole portion. The first hole portion is located on the electrode body side compared to the second hole portion. The inner dimension of the first hole portion is larger than the inner dimension of the second hole portion. The terminal has a converging portion, which has an outer diameter larger than the inner diameter of the portion with the smallest inner diameter in the terminal connection hole. At least one of the converging portion and the current collector is fused, and the converging portion is joined to the current collector through a solidified portion. A recess is formed in the solidified portion. In the thickness direction of the current collector, the bottom of the recess is located on the electrode body side compared to the second hole portion. The publication states that this configuration improves the reliability of the secondary battery.

[0004] The secondary battery to which the manufacturing method disclosed in Japanese Patent Application Publication No. 2019-125491 is intended comprises an electrode body, an outer casing, a sealing plate having a terminal insertion hole, a terminal penetrating the terminal insertion hole, and a current collector having a terminal connection hole. Before the terminal and current collector are welded, the terminal connection hole has a tapered portion that gradually increases in size at one end in the inward radial direction. The manufacturing method includes an insertion step of inserting the terminal into the terminal connection hole, a seaming step of forming a seam portion on the terminal by slitting the tapered portion, and a welding step of irradiating at least one of the seam portion of the terminal and the tapered portion of the current collector with an energy line to weld the terminal and the current collector. In the seaming step, the terminal is seamed to create a gap between the seam portion and the tapered portion. In the welding step, molten metal constituting at least one of the terminal and the current collector is introduced into the gap, and at least one of the terminal and the current collector is melted by irradiation with an energy line, forming a recess in the solidified portion formed by the solidification of the molten material. The bulletin states that this configuration improves the reliability of secondary batteries.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-10743

[0006] Patent Document 2: Japanese Patent Application Publication No. 2022-28968

[0007] Patent Document 3: Japanese Patent Application Publication No. 2019-125491 Summary of the Invention

[0008] An energy storage device, for example, includes an electrode body, a first conductive component electrically connected to the positive or negative electrode body, and a second conductive component electrically connected to the first conductive component. Here, the first conductive component and the second conductive component are sometimes joined by welding. The inventors wish to further improve the welding quality between the first conductive component and the second conductive component.

[0009] According to the technology disclosed herein, an energy storage device is provided. The energy storage device includes: an electrode body comprising a positive electrode and a negative electrode, a first conductive member electrically connected to the positive electrode or the negative electrode, and a second conductive member electrically connected to the first conductive member. The first conductive member includes a through hole. The second conductive member includes a connecting portion and a converging portion. The connecting portion is inserted into the through hole. The converging portion is provided at the end of the connecting portion and is converging at the edge of the through hole of the first conductive member. A welding portion for welding the first conductive member and the second conductive member is provided in the converging portion. A gap exists between the first conductive member and the second conductive member closer to the inside of the welding portion. The welding portion provided in the converging portion has a first welding area and a second welding area with a welding depth smaller than the first welding area. With this configuration, the welding quality between the first conductive member and the second conductive member can be further improved.

[0010] According to the technology disclosed herein, a method for manufacturing an energy storage device is provided. The manufacturing method includes a preparation step, an insertion step, a seam-sealing step, and a welding step. In the preparation step, a first conductive component having a through-hole and electrically connected to the positive electrode of an electrode body, and a second conductive component having a connecting portion electrically connected to the first conductive component are prepared. In the insertion step, the connecting portion of the second conductive component is inserted into the through-hole of the first conductive component. In the seam-sealing step, the end of the connecting portion is seamed at the edge of the through-hole of the first conductive component to form a seam. In the welding step, the seam is welded to the first conductive component by irradiation with an energy line. In the welding step, the energy line is irradiated to a state where a gap exists between the first and second conductive components, located more internally than the portion of the irradiated energy line. The welding step includes a first welding step and a second welding step. In the first welding step, an energy line is irradiated to a first region to form a first welding region. In the second welding step, an energy line is irradiated to a second region to form a second welding region with a welding depth smaller than that of the first welding region. With this configuration, the welding quality between the first and second conductive components can be further improved. Attached Figure Description

[0011] Figure 1 This is a schematic three-dimensional view of the energy storage device 1.

[0012] Figure 2 yes Figure 1 Sectional view II-II.

[0013] Figure 3 This is a schematic perspective view of the sealing plate 14 and the electrode body 20.

[0014] Figure 4 This is a schematic perspective view of the second collector component 52 and the electrode body 20.

[0015] Figure 5 This is a schematic diagram of electrode 20.

[0016] Figure 6 yes Figure 2 A magnified cross-sectional view of the vicinity of the positive end 30.

[0017] Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0018] Figure 8 This is a top view of the area near the seam 30b.

[0019] Figure 9 This is a cross-sectional view near the seam 30b.

[0020] Figure 10 This is a top view of the area near the seam 30b.

[0021] Figure 11 This is a top view of the area near the seam 30b.

[0022] Figure 12 This is a top view of the area near the seam 30b.

[0023] Explanation of reference numerals in the attached figures

[0024] 1…Electrical storage device, 10…Casing, 14…Sealing plate, 18, 19…Terminal mounting holes, 20…Electrode body, 22…Positive electrode, 24…Negative electrode, 30…Positive terminal, 30a…Connecting part, 30b…Seam section, 40…Negative terminal, 50…Positive current collector, 51h…Through hole, 51h1…Conical part, 51g1, 51g2…Slot, 51r…Recess, 51s…Gap, 60…Negative current collector, 80, 280…Welding part, 81, 281…First welding area, 82, 282…Second welding area. Detailed Implementation

[0025] The following describes one embodiment of the energy storage device disclosed herein. The embodiment described herein does not specifically limit the technology disclosed herein. Unless otherwise specified, the technology disclosed herein is not limited to the embodiment described herein. The accompanying drawings are schematic and do not necessarily reflect the actual object. Sometimes, the same reference numerals are appropriately added to components / parts that perform the same function, and repeated descriptions are omitted. Unless otherwise specified, the description of numerical ranges "A to B" means "A or more and B or less," and also includes the meaning of "greater than A and less than B."

[0026] In this specification, "energy storage device" refers to a device that generates charge and discharge by moving a charge carrier between a pair of electrodes (positive and negative electrodes) via an electrolyte. Energy storage devices include secondary batteries such as lithium-ion secondary batteries, and capacitors such as lithium-ion capacitors and double-layer capacitors. The following describes an embodiment where the energy storage device is a lithium-ion secondary battery.

[0027] Figure 1 This is a schematic three-dimensional view of the energy storage device 1. Figure 2 yes Figure 1 Sectional view II-II. (As shown) Figure 1 as well as Figure 2 As shown, the energy storage device 1 includes a housing 10, an electrode body 20, a positive terminal 30, a negative terminal 40, external conductive components 35 and 45, a positive current collector 50, a negative current collector 60, various insulating components, and an electrolyte (not shown).

[0028] The outer casing 10 is an external container for housing the electrode body 20 and the non-aqueous electrolyte. Here, the outer casing 10 is a flat, square casing. The material constituting the outer casing 10 is not particularly limited; for example, the material constituting the casing of such an energy storage device can be used.

[0029] like Figure 1 as well as Figure 2 As shown, the outer casing 10 includes an outer body 12 and a sealing plate 14. The outer body 12 has a bottom surface 12a, a pair of opposing first side surfaces 12b, and a pair of opposing second side surfaces 12c. The bottom surface 12a is rectangular in shape. Figure 2 As shown, the portion opposite to the bottom surface 12a forms an opening 12h. A pair of opposing first side surfaces 12b are rectangular in shape, extending from the long sides of the pair of opposing sides in the bottom surface 12a. A pair of opposing second side surfaces 12c are rectangular in shape, extending from the short sides of the pair of opposing sides in the bottom surface 12a. In this embodiment, the area of ​​the pair of opposing first side surfaces 12b is larger than the area of ​​the pair of opposing second side surfaces 12c.

[0030] like Figure 1 as well as Figure 2 As shown, the sealing plate 14 is a rectangular flat plate with a shape corresponding to the opening 12h. Here, the sealing plate 14 has an injection hole 15, a safety valve 17, and terminal mounting holes 18 and 19. The injection hole 15 is the portion for injecting a non-aqueous electrolyte into the housing 10. Figure 1 as well as Figure 2 As shown, the injection port 15 is sealed by the sealing component 16. The safety valve 17 is, for example, a thin-walled portion configured to release internal pressure when the internal pressure of the housing 10 rises above a specified level. The terminal mounting holes 18 and 19 are through holes for mounting the positive terminal 30 or the negative terminal 40. The sealing plate 14 seals the opening 12h and is welded (e.g., laser welded) to the outer casing 12.

[0031] Figure 3 This is a schematic perspective view of the sealing plate 14 and the electrode body 20. Figure 3 The electrode body 20 with the sealing plate 14 installed is schematically shown in the figure. Figure 4 This is a schematic perspective view of the second collector component 52 and the electrode body 20. Figure 4 The electrode body 20, on which the second current collector 52 is mounted, is schematically shown. (As shown) Figure 3 As shown, the energy storage device 1 has three electrode bodies 20. (As indicated...) Figure 3 as well as Figure 4 As shown, in the electrode body 20, the second current collector 52 of the positive current collector 50 is mounted on one side in the long side direction Y. Figure 3 as well as Figure 4 (On the left side), the second collector component 62 of the negative collector 60 is installed on the other side in the long side direction Y. Figure 3 as well as Figure 4 (The right side). For example, Figure 2 As shown, the electrode body 20 is disposed inside the outer casing 12, covered by an electrode body retainer 29 made of a resin sheet such as polypropylene (PP). The number of electrode bodies 20 in the energy storage device 1 is not particularly limited; for example, it may be one, two, or more than four.

[0032] Figure 5 This is a schematic diagram of electrode body 20. (For example...) Figure 5 As shown, the electrode body 20 includes a positive electrode 22, a negative electrode 24, and a separator 26. The electrode body 20 is a wound electrode body formed by stacking elongated sheet-shaped positive electrodes 22 and negative electrodes 24, sandwiching elongated sheet-shaped separators 26, and then winding them along their long sides. Figures 2-4 As shown, the electrode body 20 includes a main body 20a, a positive electrode tab group 23, and a negative electrode tab group 25. The main body 20a is the part in which the positive electrode 22, the negative electrode 24, and the diaphragm 26 are stacked, and is, for example, flat in shape.

[0033] The width of the main body 20a is not particularly limited and can be 10cm or more, 20cm or more, or 30cm or more. The width of the main body 20a can be 50cm or less or 40cm or less. In this specification, "width of the main body 20a" refers to the length of the main body 20a along the direction of the winding axis WL of the electrode body 20.

[0034] like Figure 1 , Figure 2 as well as Figure 5 As shown, the electrode body 20 is disposed inside the outer casing 12 with its winding axis WL parallel to the width direction Y. In this embodiment, the electrode body 20 is disposed inside the outer casing 12 with its winding axis WL parallel to the bottom surface 12a and orthogonal to the second side surface 12c. Furthermore, the two end faces of the electrode body 20 along the direction of the winding axis WL are opposite to the second side surface 12c of the outer casing 12. In this specification, for ease of explanation, the side closest to the positive current collector 50 ( Figure 2 as well as Figure 4 The end face of the electrode body 20 (main body 20a) opposite the second side surface 12c (on the left side of the width direction Y) is called the "first end face 201". The side closest to the negative electrode current collector 60 ( Figure 2 as well as Figure 4 The end face of the electrode body 20 (main body 20a) opposite the second side surface 12c (to the right of the width direction Y) is called "second end face 202".

[0035] The positive electrode 22 has a strip-shaped positive electrode current collector foil 22c (e.g., aluminum foil) and a positive electrode active material layer 22a fixed to at least one surface of the positive electrode current collector foil 22c. Although not particularly limited, a protective layer 22p may be provided on one side edge in the width direction Y of the positive electrode 22 as needed. The materials constituting the positive electrode active material layer 22a and the protective layer 22p can be any materials used in this type of secondary battery without particular limitation.

[0036] At one end of the positive electrode current collector foil 22c in the width direction Y ( Figure 5 Multiple positive electrode tabs 22t are provided at the left end. The multiple positive electrode tabs 22t are respectively oriented towards one side of the width direction Y ( Figure 5 (on the left side). Multiple positive electrode tabs 22t are provided at intervals (intermittently) along the long side of the positive electrode 22. The positive electrode tabs 22t are part of the positive electrode current collector foil 22c, and are the exposed portions of the current collector foil 22c where neither the positive electrode active material layer 22a nor the protective layer 22p is formed. In this embodiment, the multiple positive electrode tabs 22t protrude beyond the separator 26 in the width direction Y. At one end in the width direction Y ( Figure 5 Multiple positive electrode tabs 22t are stacked at the left end to form a positive electrode tab group 23 (see reference). Figures 2-4 ).

[0037] The negative electrode 24 has an elongated strip-shaped negative electrode current collector foil 24c (e.g., copper foil) and a negative electrode active material layer 24a fixed to at least one surface of the negative electrode current collector foil 24c. The material constituting the negative electrode active material layer 24a can be any material used in this type of secondary battery without particular limitation.

[0038] At one end of the negative electrode current collector foil 24c in the width direction Y ( Figure 5 Multiple negative electrode tabs 24t are provided at the right end. The multiple negative electrode tabs 24t face one side of the width direction Y. Figure 5 (on the right side). Multiple negative electrode tabs 24t are provided at intervals (intermittently) along the long side of the negative electrode 24. Here, the negative electrode tabs 24t are part of the negative electrode current collector foil 24c, and are the exposed portion of the current collector foil 24c where the negative electrode active material layer 24a is not formed. In this embodiment, the negative electrode tabs 24t protrude in the width direction Y from the separator 26. At one end in the width direction Y ( Figure 5 Multiple negative electrode tabs 24t are stacked at the right end to form a negative electrode tab group 25 (refer to...). Figures 2-4 ).

[0039] The separator 26 insulates the positive electrode active material layer 22a of the positive electrode 22 from the negative electrode active material layer 24a of the negative electrode 24. The separator 26 forms the outer surface of the electrode body 20a. As the separator 26, for example, a porous sheet made of a resin composed of a polyolefin resin such as polyethylene (PE) or polypropylene (PP) can be used.

[0040] like Figures 1-3 As shown, the positive terminal 30 and the negative terminal 40 are mounted on the sealing plate 14. In this embodiment, the positive terminal 30 is disposed at one end of the sealing plate 14 in the long side direction Y. Figures 1-3 (The left end). In this embodiment, the negative end 40 is disposed at the end of the sealing plate 14 on the other side in the long side direction Y ( Figures 1-3 (The right end). The positive terminal 30 or the negative terminal 40 is an example of a "second conductive component" in the energy storage device and its manufacturing method disclosed herein. Therefore, in this specification, the positive terminal 30 and / or the negative terminal 40 may be appropriately replaced with "second conductive component".

[0041] like Figure 2 As shown, the positive terminal 30 is located inside the outer casing 12 via the positive current collector 50 and the positive terminal 22 of the electrode body 20 (see reference). Figure 5 Electrical connection. The positive terminal 30 is led out from the inside of the sealing plate 14 to the outside through the terminal mounting hole 18. The positive terminal 30 is insulated from the sealing plate 14 by a first insulating member 71 and a second insulating member 72. Preferably, the positive terminal 30 is made of aluminum or an aluminum alloy. An external conductive member 35 is fixed on the positive terminal 30. The positive terminal 30 is engaged with the external conductive member 35.

[0042] Figure 6 yes Figure 2 A magnified cross-sectional view of the vicinity of the positive end 30. Figure 6 schematically shown Figure 2 The cross-sectional structure near the positive terminal 30 along the thickness direction of the sealing plate 14. Figure 6 For ease of explanation, the structure of the electrode body 20 side of the sealing plate 14 is shown on the upper side of the attached drawing, and the structure of the outer side of the sealing plate 14 is shown on the lower side of the attached drawing. Figure 7 as well as Figure 9 (The same applies). For example... Figure 6 As shown, the positive terminal 30 includes a connecting portion 30a, a slit portion 30b, a flange portion 30c, and a protrusion portion 30d.

[0043] Here, the connecting part 30a is cylindrical. For example... Figure 6As shown, the connecting portion 30a extends from the flange portion 30c and is inserted into the terminal mounting hole 18 of the housing 10 and the through hole 51h of the positive current collector 50. The outer diameter of the connecting portion 30a is smaller than the diameter of the terminal mounting hole 18 and the diameter of the through hole 51h. The front end of the connecting portion 30a is sutured to the edge of the through hole 51h. Thus, the positive terminal 30 is electrically connected to the positive current collector 50.

[0044] Here, the converging slit portion 30b is provided at the end of the connecting portion 30a. In this embodiment, the converging slit portion 30b is a portion converging and sewn into the edge of the through hole 51h of the positive current collector 50. Therefore, the diameter of the converging slit portion 30b is larger than the diameter of the connecting portion 30a. In this embodiment, the converging slit portion 30b is provided at the end of the connecting portion 30a (here, the end opposite to the flange portion 30c). Figure 6 As shown, the seam portion 30b has a welded portion 80. The welded portion 80 will be described further later.

[0045] Here, the flange portion 30c is circular. Preferably, the diameter of the flange portion 30c is larger than the inner diameter of the terminal mounting hole 18. For example... Figure 6 As shown, a connecting portion 30a is provided on one side of the flange portion 30c (the side facing the sealing plate 14). A protrusion 30d is provided on the other side of the flange portion 30c (the side facing the external conductive member 35). The flange portion 30c is disposed along the outer surface 14a of the sealing plate 14. In this embodiment, the flange portion 30c is housed in a recess 14a1 provided on the outer surface 14a of the sealing plate 14.

[0046] Here, the protrusion 30d appears roughly ring-shaped when viewed from above. For example... Figure 6 As shown, the protrusion 30d protrudes from the flange 30c. The protrusion 30d is inserted into the through hole 35h of the external conductive member 35. The protrusion 30d engages with the inner wall of the through hole 35h (engagement portion 35W).

[0047] Here, the external conductive component 35 is plate-shaped and has a through hole 35h. For example... Figure 6 As shown, the external conductive component 35 is arranged along the outer surface 14a of the sealing plate 14. In this embodiment, the external conductive component 35 is electrically connected to the positive terminal 30 by inserting and engaging the protrusion 30d of the positive terminal 30 inside the through hole 35h. When constructing the energy storage module, a busbar is joined to the external conductive component 35. Preferably, the external conductive component 35 is made of, for example, aluminum or an aluminum alloy.

[0048] like Figure 2As shown, the positive current collector 50 electrically connects the positive electrode 22 of the electrode body 20 to the positive terminal 30 inside the outer casing 12. In this embodiment, a portion of the positive current collector 50 is connected to the positive terminal 30. Another portion of the positive current collector 50 is connected to the positive electrode tab assembly 23 of the electrode body 20. Preferably, the positive current collector 50 is made of aluminum or an aluminum alloy, for example. The positive current collector 50 and / or the negative current collector 60 are examples of the "first conductive component" in the energy storage device and its manufacturing method disclosed herein. Therefore, in this specification, the positive current collector 50 and / or the negative current collector 60 may be appropriately replaced with the "first conductive component".

[0049] like Figure 2 As shown, the positive current collector 50 has a first current collector 51 and a second current collector 52. In this embodiment, the first current collector 51 has an L-shaped cross-section and has a first plate portion 511 and a second plate portion 512. Here, the first plate portion 511 is plate-shaped and extends from the second plate portion 512 toward the bottom surface 12a of the outer casing 12. The second current collector 52 is connected to the first plate portion 511. Here, the second plate portion 512 is plate-shaped. Figure 6 As shown, the second plate portion 512 is disposed along the inner surface 14b of the sealing plate 14. In the second plate portion 512, on the second side surface 12c (refer to...) Figure 1 The end of the first plate 511 is connected to the side of the plate.

[0050] Figure 7 yes Figure 6 A magnified view of a portion of the image. Figure 7 Shown in partial magnification Figure 6 The area near the seam 30b in the middle. For example... Figure 6 as well as Figure 7 As shown, the second plate portion 512 has a recess 51r. The recess 51r is a portion of the second plate portion 512 that is recessed from the first surface 512a. The first surface 512a is the surface on the bottom surface 12a side of the outer body 12 in the second plate portion 512. Figure 7 As shown, a through hole 51h is provided on the bottom surface 51r1 of the recess 51r. In this embodiment, the diameter of the bottom surface 51r1 is larger than the diameter of the through hole 51h.

[0051] exist Figure 7In the illustrated configuration, a tapered portion 51h1 and a non-tapered portion 51h2 are provided on the inner wall of the through hole 51h. The tapered portion 51h1 is connected to the bottom surface 51r1 of the recess 51r and slopes from the bottom surface 51r1. In this embodiment, the tapered portion 51h1 slopes from the bottom surface 51r1 and reaches the non-tapered portion 51h2. The diameter of the tapered portion 51h1 gradually decreases towards the non-tapered portion 51h2. The non-tapered portion 51h2 is connected to the tapered portion 51h1 and reaches the second surface 512b. The second surface 512b is the surface opposite to the first surface 512a in the second plate portion 512, and is disposed here on the sealing plate 14 side. The diameter of the non-tapered portion 51h2 is constant from the boundary with the tapered portion 51h1 to the second surface 512b.

[0052] In this embodiment, at least a portion of the slit portion 30b is disposed within the recess 51r. Figure 7 In the arrangement shown, a gap 51s is present between the bottom surface 51r1 of the recess 51r, the side surface 51r2 of the recess 51r, and the converging portion 30b. Here, the gap 51s is located on the inner side compared to the welded portion 80 (in a cross-sectional view along the thickness direction of the sealing plate 14, it is located on the side of the sealing plate 14 compared to the welded portion 80 (see reference 14)). Figure 6 as well as Figure 7 When viewed from above, the gap 51s can be annular. Preferably, when viewed from above, the gap 51s is continuously located around the converging portion 30b. Although not particularly limited, the cross-sectional area of ​​the gap 51s in the direction orthogonal to the direction in which the connecting portion 30a extends is, for example, 0.0005 mm. 2 The preferred value is 0.0015mm. 2 That's it. The cross-sectional area is approximately 0.01 mm. 2 That's all.

[0053] Figure 8 This is a top view near the seam 30b. Figure 8 The structure near the seam 30b in the first surface 512a of the second plate portion 512 is shown. (As shown) Figure 6 as well as Figure 8 As shown, in the second plate portion 512, in the first surface 512a, grooves 51g1 and 51g2 are provided around the through hole 51h. Figure 8 In the arrangement shown, grooves 51g1 and 51g2 are provided around the converging joint 30b. Grooves 51g1 and 51g2 are C-shaped when viewed from above. Here, the converging joint 30b is sandwiched between grooves 51g1 and 51g2. Figure 8 In the arrangement shown, grooves 51g1 and 51g2 are discontinuous. Therefore, a portion of the concave slit 30b is not surrounded by either groove 51g1 or groove 51g2. The depths of grooves 51g1 and 51g2 are not particularly limited and can be smaller than the depth of recess 51r.

[0054] like Figure 8 As shown, the welded portion 80 includes a first welded region 81 and a second welded region 82. The second welded region 82 is a region with a weld depth smaller than that of the first welded region 81. In this embodiment, from the viewpoint of achieving the technical effects disclosed herein, the ratio (D1 / D2) of the weld depth D1 of the first welded region 81 to the weld depth D2 of the second welded region 82 is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 2 or more. On the other hand, (D1 / D2) is approximately 5 or less, for example, 4.5 or less, preferably 4 or less, more preferably 3.5 or less, and even more preferably 3 or less. The weld depth D1 and weld depth D2 are calculated by cutting the welded portion 80 along the thickness direction of the sealing plate 14 and observing the cross-section using a microscope (e.g., SEM) and measuring the length of the molten portion.

[0055] like Figure 8 As shown, the weld portion 80 is provided circumferentially along the converging joint portion 30b. In this embodiment, the weld portion 80 is provided circumferentially along the portion of the converging joint portion 30b surrounded by the groove portion 51g1 or the groove portion 51g2. Therefore, two weld portions 80 are provided in the converging joint portion 30b. Here, the two weld portions 80 are not continuous.

[0056] In this embodiment, in the welding section 80, a first welding area 81 and a second welding area 82 are alternately arranged circumferentially in the seam convergence section 30b. Figure 8 In the manner shown, in each welding section 80, a first welding area 81, a second welding area 82, and the first welding area 81 are sequentially arranged from the first end 80e1 toward the second end 80e2.

[0057] While not particularly limiting, from the viewpoints of better achieving the technical effects disclosed herein, more efficiently implementing the welding process, and improving the conductivity between the positive current collector 50 and the positive terminal 30, it is preferable that the first welding region 81 and the second welding region 82 are continuous in the welding section 80. In this embodiment, the first welding region 81, the second welding region 82, and the first welding region 81 are continuous from the first end 80e1 toward the second end 80e2. While not particularly limiting, from the same viewpoint, the length L1 of the first welding region 81 when viewed from above is, for example, 2 mm or more, preferably 3 mm or more, and more preferably 5 mm or more. The length L2 of the second welding region 82 when viewed from above is, for example, 2 mm or more, preferably 3 mm or more, and more preferably 5 mm or more. The upper limit of the length L1 and the upper limit of the length L2 can be set to, for example, 20 mm, but are not particularly limited, and can be appropriately set according to the number of welding regions to be provided in the welding section 80, the size of the welding section 80, etc.

[0058] like Figures 2-4 As shown, the second current collector 52 extends toward the bottom surface 12a of the outer casing 12. The second current collector 52 has a first connecting portion 52a and a second connecting portion 52b. The first connecting portion 52a is electrically connected to the first current collector 51. In this embodiment, the first connecting portion 52a is connected to the first current collector 51 via a connecting portion 521. The first connecting portion 52a extends in the vertical direction Z. In this embodiment, the first connecting portion 52a is configured to be substantially perpendicular to the winding axis WL of each electrode body 20.

[0059] like Figure 3 as well as Figure 4 As shown, a fuse 52f is formed in the first connection portion 52a. The first connection portion 52a is configured such that the fuse 52f blows when a current of 1000A or more (e.g., a short-circuit current) flows through the energy storage device 1. The cross-sectional area of ​​the fuse 52f is smaller than that of the other parts of the first connection portion 52a except for the fuse 52f and the connection portion 521. The fuse 52f is, for example, an opening, a thin-walled portion, etc. Because the first connection portion 52a has the fuse 52f, it is configured to blow when a current as described above flows through it.

[0060] The second connecting portion 52b engages with the positive electrode tab assembly 23. In this embodiment, the second connecting portion 52b extends along the vertical direction Z. The second connecting portion 52b is configured to be substantially perpendicular to the winding WL of each electrode body 20. The surface of the second connecting portion 52b that connects to the plurality of positive electrode tabs 22t is configured to be substantially parallel to the second side surface 12c of the outer casing 12.

[0061] like Figure 2 As shown, the negative terminal 40 is located inside the outer casing 12 via the negative current collector 60 and the negative terminal 24 of the electrode body 20 (see reference). Figure 5 Electrical connection. The negative terminal 40 is led out from the inside of the sealing plate 14 to the outside through the terminal mounting hole 19. The negative terminal 40 is insulated from the sealing plate 14 by the first insulating member 71 and the second insulating member 72. Preferably, the negative terminal 40 is made of copper or copper alloy, for example. An external conductive member 45 (made of copper or copper alloy) is fixed on the negative terminal 40. The negative terminal 40 is engaged with the external conductive member 45. The construction of the negative terminal 40, its connection with the negative current collector 60, etc., can be the same as the construction of the positive terminal 30 and its connection with the positive current collector 50 described above. Therefore, the description is omitted here.

[0062] like Figure 2As shown, the negative current collector 60 electrically connects the negative electrode 24 of the electrode body 20 to the negative terminal 40 inside the outer casing 12. In this embodiment, a portion of the negative current collector 60 is connected to the negative terminal 40. The remaining portion of the negative current collector 60 is connected to the negative electrode tab assembly 25 of the electrode body 20. Preferably, the negative current collector 60 is made of, for example, copper or a copper alloy. The structure of the negative current collector 60, its connection to the negative electrode tab assembly 25, etc., can be the same as the structure of the positive current collector 50 and the connection between the positive current collector 50 and the positive electrode tab assembly 23 described above. Therefore, the description is omitted here. Figure 4 In the figure, reference numeral "621" indicates the connecting part, reference numeral "62a" indicates the first connecting part, reference numeral "62b" indicates the second connecting part, and reference numeral "62f" indicates the fuse.

[0063] Various insulating components include, for example, the electrode holder 29, the first insulating component 71, the second insulating component 72, and the third insulating component 73 (see reference). Figure 2 as well as Figure 6 ).like Figure 2 As shown, the first insulating member 71 is disposed between the positive current collector 50 and the sealing plate 14, and between the negative current collector 60 and the sealing plate 14. The first insulating member 71 may also include a portion that insulates the electrode body 20 from the sealing plate 14 (see Figure 1). Figure 2 The second insulating component 72 is disposed between the positive terminal 30 and the sealing plate 14, and between the negative terminal 40 and the sealing plate 14. The third insulating component 73 is disposed between the external conductive component 35 and the sealing plate 14, and between the external conductive component 45 and the sealing plate 14. The materials used to construct the first insulating component 71, the second insulating component 72, and the third insulating component 73 may, for example, be the same as those used to construct insulating components for the same purpose in such energy storage devices.

[0064] As an electrolyte, the electrolyte used as the electrolyte in this type of energy storage device can be used without particular restrictions.

[0065] The energy storage device 1 can be used for various purposes, such as preferably as a power source (drive power source) for motors in vehicles such as passenger cars and trucks. The type of vehicle is not particularly limited; examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). The energy storage device 1 can also be used, for example, as a single battery included in an energy storage module.

[0066] The manufacturing method of the energy storage device 1 includes, for example, a preparation process, an arrangement process, an insertion process, a seam closing process, and a welding process. Hereinafter, the manufacturing method of the energy storage device 1 will be described with appropriate reference to the accompanying drawings.

[0067] In the preparation process, a positive current collector 50 with a through hole 51h is prepared to be electrically connected to the positive electrode 22 or the negative electrode 24 of the electrode body 20, and a positive terminal 30 with a connection portion 30a is prepared to be electrically connected to the positive current collector 50. The sealing plate 14, the first insulating component 71, and the second insulating component 72 can be prepared together in the preparation process.

[0068] In the configuration step, the components prepared in the preparation step are arranged in designated positions. For example, in the configuration step, the first insulating component 71 and the second insulating component 72 are first installed onto the sealing plate 14. Next, the second plate portion 512 of the positive current collector 50 is overlapped with the first insulating component 71. The order of this arrangement is not particularly limited and can be appropriately varied. In other embodiments, the sealing plate 14 may be prepared in the preparation step for several components, excluding the positive terminal 30, to be installed. In this case, in the configuration step, it is sufficient to appropriately arrange the components that were not installed in the designated positions in the preparation step. Alternatively, the configuration step may be omitted.

[0069] In the insertion process, the connecting portion 30a of the positive terminal 30 is inserted into the through hole 51h of the positive current collector 50. In this embodiment, in the insertion process, the connecting portion 30a is inserted into the through hole 51h of the positive current collector 50 such that the flange portion 30c of the positive terminal 30 is disposed on the outer surface 14a side of the sealing plate 14 and the connecting portion 30a protrudes from the inner surface 14b side of the sealing plate 14.

[0070] In the riveting process, the end of the connecting portion 30a is riveted to the edge of the through hole 51h of the positive current collector 50 to form the riveted portion 30b. In the riveting process, the riveting process used in the manufacturing process of such energy storage devices can be used without particular restriction.

[0071] Figure 9 This is a sectional view of the area near the seam section 30b after the seam-seaming process. Figure 9 The diagram schematically illustrates the positional relationship between the slit portion 30b after the slit-sealing process, the recess 51r of the positive current collector 50, and the through hole 51h. (Example) Figure 9 As shown, after the seam-closing process, a gap 51s is formed between the bottom surface 51r1 of the recess 51r, the side surface 51r2 of the recess 51r, and the seam-closing portion 30b.

[0072] In the welding process, the converging seam 30b is welded to the positive current collector 50 by irradiation with an energy line. During the welding process, the energy line is irradiated while the gap between the positive current collector 50 and the positive terminal 30 (here, gap 51s) is located on the inner side compared to the portion irradiated with the energy line. Figure 9In the manner shown, an energy line (arrow A) is irradiated along the edge of the recess 51r in the positive current collector 50. This allows for the generation of energy that is more concentrated on the inner side than the portion being irradiated (in a cross-sectional view along the thickness direction of the sealing plate 14, the side closer to the sealing plate 14 than the weld portion 80 (see reference 14)). Figure 6 as well as Figure 7 While leaving a gap of 51s, the closed gap 30b is welded to the positive current collector 50.

[0073] Figure 10 This is a top view near the seam 30b. Figure 10 The diagram shows the structure near the seam 30b in a plane viewed from the first surface 512a side of the second plate portion 512 of the positive electrode current collector 50 before the welding process. The welding process includes a first welding process and a second welding process. Here, the first welding process is the process of irradiating an energy line into the first region R1 to form the first welding region 81 (see reference). Figure 8 as well as Figure 10 Here, the second welding process is the process of irradiating the second region R2 with energy lines to form the second welding region 82 (see reference). Figure 8 as well as Figure 10 While not specifically limited, the dose of energy rays irradiated in the second welding process can be lower than the dose of energy rays irradiated in the first welding process. For example, the dose of energy rays irradiated in each process can be appropriately set according to the desired welding depth in the first welding region 81 and the second welding region 82.

[0074] In this embodiment, a first welding process and a second welding process are alternately performed during the welding process to alternately provide a first welding area 81 and a second welding area 82 in the circumferential direction of the weld joint 30b. Figure 10 In the illustrated configuration, a first welding operation is performed from the welding start point S1 towards the end point E1 in a first region R1 containing the welding start point S1. Immediately following the first welding operation, a second welding operation is performed in a second region R2 adjacent to the first region R1. Then, immediately following the second welding operation, the first welding operation is performed again in the first region R1 containing the end point E1, which is adjacent to the second region R2. Thus, a configuration is established... Figure 8 The first welding area 81 and the second welding area 82 are shown. In this embodiment, the welding start point S1 becomes the first end 80e1 of the welding portion 80 (refer to...). Figure 8 as well as Figure 10 End point E1 becomes the second end 80e2 of welded part 80 (refer to...). Figure 8 as well as Figure 10 ).

[0075] For the energy line irradiation used in the welding process, energy sources such as light energy, heat energy, and electronic energy are preferably used. For example, laser welding is preferably used to perform the welding process. Among these, a continuously oscillating laser is preferred for performing the welding process. Although not particularly limited, in this embodiment, a green laser can be preferred.

[0076] The same preparation, configuration, insertion, and welding processes are performed on the negative electrode side.

[0077] After the welding process, for example, an electrode body 20 is installed on the component obtained by the welding process. The electrode body 20 can be manufactured using conventionally known methods. In this embodiment, a second current collector 52 of a positive current collector 50 is installed on the positive electrode tab group 23 of the electrode body 20, and a second current collector 62 of a negative current collector 60 is installed on the negative electrode tab group 25. Next, the second current collectors 52 and 62 installed on the electrode body 20 are installed on first current collectors 51 and 61 of the same polarity in the component obtained by the welding process. Next, the electrode body 20 is housed in the electrode body holder 29. Next, the electrode body 20 covered by the electrode body holder 29 is housed in the outer casing 12. In this state, a sealing plate 14 is overlapped onto the opening 12h of the outer casing 12 and welded to seal the outer casing 12.

[0078] After the outer casing 12 is sealed, electrolyte is injected into the battery casing 10 through the injection port 15 using conventional methods. Following the electrolyte injection, the injection port 15 is sealed using a sealing member 16. Next, with the injection port 15 sealed by the sealing member 16, laser welding or similar methods are performed to seal the injection port 15. After sealing the injection port 15, an energy storage device 1 in a usable state can be obtained, for example, by initial charging and aging under specified conditions.

[0079] As described above, the manufacturing method of the energy storage device 1 includes a preparation step, an insertion step, a seam-sealing step, and a welding step. In the preparation step, a positive current collector 50 (first conductive member) with a through hole 51h, electrically connected to the positive electrode 22 of the electrode body 20, and a positive terminal 30 (second conductive member) with a connecting portion 30a, electrically connected to the positive current collector 50, are prepared. In the insertion step, the connecting portion 30a of the positive terminal 30 is inserted into the through hole 51h of the positive current collector 50. In the seam-sealing step, the end of the connecting portion 30a is seamed to the edge of the through hole 51h of the positive current collector 50 to form a seam portion 30b. In the welding step, the seam portion 30b is welded to the positive current collector 50 by irradiation with an energy line. In the welding step, an energy line is irradiated with the gap 51s between the positive current collector 50 and the positive terminal 30 located on the inner side compared to the portion of the irradiated energy line. The welding step includes a first welding step and a second welding step. In the first welding process, an energy line is irradiated onto a first region R1 to form a first welding region 81. In the second welding process, an energy line is irradiated onto a second region R2 to form a second welding region 82 with a welding depth smaller than that of the first welding region 81.

[0080] In other words, in the manufacturing method of the energy storage device 1, the weld joint 30b and the positive current collector 50 are welded together with a gap 51s between the positive current collector 50 and the positive terminal 30. This allows gases and fumes generated during welding to escape through the gap 51s simultaneously with the welding. Therefore, porosity in the welded portion 80 can be suppressed. This further improves the welding quality between the positive current collector 50 and the positive terminal 30. Furthermore, the welding process includes a first welding process and a second welding process with a second welding area 82. In the first welding process, by providing a first welding area 81 with a relatively large welding depth, the gap 51s remaining in such an area can be made smaller. Therefore, by implementing the first welding process, the conductivity between the positive current collector 50 and the positive terminal 30 can be improved. In the second welding process, a second welding area 82 with a relatively small welding depth is provided. Therefore, the amount of gases and fumes generated can be reduced. In addition, welding can be performed while leaving a larger gap 51s. Therefore, it can discharge gases and fumes more efficiently, and further improve the welding quality between the positive current collector 50 and the positive terminal 30.

[0081] The energy storage device 1 manufactured by the above-described manufacturing method comprises: an electrode body 20 including a positive electrode 22 and a negative electrode 24, a positive current collector 50 (first conductive member) electrically connected to the positive electrode 22, and a positive terminal 30 (second conductive member) electrically connected to the positive current collector 50. The positive current collector 50 includes a through hole 51h. The positive terminal 30 includes a connecting portion 30a and a converging portion 30b. The connecting portion 30a is inserted into the through hole 51h. The converging portion 30b is provided at the end of the connecting portion 30a and is converging at the edge of the through hole 51h of the positive current collector 50. A welding portion 80 is provided in the converging portion 30b for welding the positive current collector 50 to the positive terminal 30. A gap 51s between the positive current collector 50 and the positive terminal 30 is present on the inner side compared to the welding portion 80. The welding section 80, which is provided in the seam section 30b, has a first welding area 81 and a second welding area 82 with a welding depth smaller than that of the first welding area 81.

[0082] In the energy storage device 1, a gap 51s exists between the positive current collector 50 and the positive terminal 30 at the welding portion 80. The welding portion 80 has a first welding region 81 with a relatively large welding depth and a second welding region 82 with a relatively small welding depth. Therefore, in the first welding region 81, the gap 51s is relatively smaller, further improving the conductivity between the positive current collector 50 and the positive terminal 30. During the formation of the second welding region 82, since the welding depth of the second welding region 82 is even smaller, the generation of gases and fumes during welding can be reduced, and the relatively larger gap 51s facilitates the discharge of gases and fumes. Therefore, in the first welding region 81 and the second welding region 82, the generation of porosity can be suppressed, further improving the welding quality of the welding portion 80 between the positive current collector 50 and the positive terminal 30.

[0083] The energy storage device 1 may also include a housing 10 for housing the electrode body 20. The housing 10 may have a terminal mounting hole 18. The positive terminal 30 can be inserted into the terminal mounting hole 18. With this configuration, the electrical connectivity of the electrode body 20, the positive current collector 50, and the positive terminal 30 can be improved.

[0084] The positive current collector 50 may have a recess 51r. A through hole 51h may be provided on the bottom surface 51r1 of the recess 51r. At least a portion of the converging slot 30b may be disposed within the recess 51r. The slot 51s may be located between the bottom surface 51r1 of the recess 51r, the side surface 51r2 of the recess 51r, and the converging slot 30b. Thus, the slot 51s can be more reliably retained in the weld portion 80, and the technical effects disclosed herein can be better achieved.

[0085] A tapered portion 51h1, which is connected to the bottom surface 51r1 of the recess 51r and inclined from the bottom surface 51r1, can be provided on the inner wall of the through hole 51h. This makes it easier to ensure the mechanical bonding strength between the converging portion 30b and the edge of the through hole 51h.

[0086] In the positive current collector 50, on the surface (first surface 512a) where the slit portion 30b is provided, grooves 51g1 and 51g2 can be provided around the slit portion 30b. This can suppress the phenomenon (collapse) where metal around the slit portion 30b (in this embodiment, the edge of the recess 51r, the side surface 51r2, etc.) flows to the outside of the slit portion due to welding.

[0087] In the welding process, the first welding step and the second welding step can be performed alternately to alternately set the first welding area 81 and the second welding area 82 in the circumferential direction of the weld joint 30b. This allows for welding to be performed in areas where a smaller gap 51s is maintained, and in areas where welding is performed while maintaining a larger gap 51s. Therefore, it is possible to improve welding quality by suppressing the generation of gases and fumes generated during welding and efficiently removing such gases and fumes, while ensuring appropriate welding depth and welding range.

[0088] In the welding process, a first welding step can be performed on a first region R1 containing the welding start point S1, followed immediately by a second welding step. At the start of welding, there are no areas around the first region R1 containing the welding start point S1 that are to be welded. Therefore, even if gases or fumes are generated during welding, their escape path (gap 51s) can be ensured. In the second welding step, because the welding depth is smaller, the generation of gases or fumes can be suppressed. This allows for more efficient suppression of porosity.

[0089] While not particularly limited, in the above-described manner, the first welding step can be performed immediately following the second welding step. This, for example, increases the size of the first welding region 81 in the welding section 80. Therefore, the conductivity between the positive current collector 50 and the positive terminal 30 can be further improved.

[0090] The above description illustrates the implementation methods of the disclosed technology. However, these implementation methods are merely illustrative and do not limit the technical solutions. The technology described in the technical solutions includes various modifications and alterations to the above-illustrative implementation methods.

[0091] Figure 11 This is a top view near the seam 30b. Figure 11 The diagram shows the structure near the slit portion 30b in the first surface 512a of the second plate portion 512, as in another embodiment. Figure 11 In the manner shown, a welding portion 280 is provided in the seam portion 30b for welding the positive current collector 50 to the positive terminal 30. In each welding portion 280, a second welding region 282, a first welding region 281, and a second welding region 282 are sequentially provided from the first end 280e1 toward the second end 280e2.

[0092] Figure 12 This is a top view near the seam 30b. Figure 12 The diagram shows the structure near the seam 30b on a plane viewed from the first surface 512a side of the second plate portion 512 of the positive current collector 50, prior to the welding process, in another embodiment. Figure 12 In the illustrated configuration, a second welding process is performed from the welding start point S2 towards the end point E2 in a second region R22 containing the welding start point S2. Immediately following the second welding process, a first welding process is performed in a first region R21 adjacent to the second region R22. Then, immediately following the first welding process, a first welding process is performed in the second region R22, which is adjacent to the first region R21 and contains the end point E2. Thus, a configuration is established... Figure 11 The first welding area 281 and the second welding area 282 are shown. In this embodiment, the welding start point S2 becomes the first end 280e1 of the welding portion 280 (see reference). Figure 11 as well as Figure 12 End point E2 becomes the second end 280e2 of welded part 280 (refer to...) Figure 11 as well as Figure 12 ).

[0093] As described above, in the manufacturing method disclosed here, the welding process can begin by performing a second welding process in the second region R22 containing the welding start point S2, and the first welding process is performed immediately following the second welding process. At the start of welding, there are no areas to be welded around the second region R22 containing the welding start point S2. Therefore, even if gases or fumes are generated during the second welding process, they can be easily discharged. In the subsequent first welding process, more gases or fumes may be generated than in the second welding process, but since the reduction of the weld gap 51s caused by welding can be suppressed by performing the second welding process, the gases or fumes generated in the first welding process can be discharged efficiently. This allows for more efficient suppression of porosity formation.

[0094] While not particularly limited, in the above-described manner, a second welding step can be performed immediately following the first welding step. Thus, for example, it is possible to weld the positive current collector 50 to the positive terminal 30 while suppressing the generation of gases, fumes, etc., and retaining a larger gap 51s for venting these gases and fumes.

[0095] The number, length, and configuration of the first and second welding areas included in the welding section are not particularly limited, and can be appropriately set as long as the technical effects disclosed herein can be achieved.

[0096] The techniques disclosed herein can include the methods described in the following items.

[0097] Item 1: An energy storage device, comprising:

[0098] An electrode body, comprising a positive electrode and a negative electrode;

[0099] The first conductive component is electrically connected to either the positive or negative electrode; and

[0100] The second conductive component is electrically connected to the first conductive component.

[0101] The aforementioned first conductive component includes a through hole.

[0102] The second conductive component mentioned above includes:

[0103] The connecting part is inserted into the aforementioned through hole; and

[0104] A converging slit is provided at the end of the connecting portion and is converging slit at the edge of the through hole of the first conductive member.

[0105] The aforementioned seam portion is provided with a welding part for welding the first conductive component and the second conductive component.

[0106] A gap exists between the first conductive component and the second conductive component on the inner side of the welded portion.

[0107] The weld portion provided at the aforementioned seam has a first weld area and a second weld area with a weld depth smaller than that of the first weld area.

[0108] Item 2: According to the energy storage device described in Item 1, wherein,

[0109] It also has a housing to accommodate the aforementioned electrodes.

[0110] The aforementioned housing has terminal mounting holes.

[0111] The second conductive component is a terminal that is inserted into the terminal mounting hole.

[0112] Item 3: The energy storage device described in Item 1 or 2, wherein,

[0113] The first conductive component described above has a recess.

[0114] The aforementioned through hole is provided on the bottom surface of the aforementioned recess.

[0115] At least a portion of the aforementioned slit portion is disposed within the aforementioned recess.

[0116] The gap is located between the bottom surface of the recess, the side surface of the recess, and the constricted joint.

[0117] Item 4: According to the energy storage device described in Item 3, wherein,

[0118] A tapered portion is provided on the inner wall of the aforementioned through hole, which is connected to the bottom surface of the aforementioned recess and inclined from the bottom surface.

[0119] Item 5: According to any one of items 1 to 4, of which,

[0120] In the surface of the first conductive component where the aforementioned slit portion is provided, a groove is provided around the slit portion.

[0121] Item 6: According to any one of the energy storage devices described in items 1 to 5, wherein,

[0122] The first welding area and the second welding area are alternately provided in the circumferential direction of the aforementioned seam.

[0123] Item 7: A manufacturing method for an energy storage device comprising an electrode body including a positive electrode and a negative electrode, comprising:

[0124] The preparation process includes preparing a first conductive component with a through hole that is electrically connected to the positive or negative electrode of the electrode body, and a second conductive component with a connection portion that is electrically connected to the first conductive component.

[0125] In the insertion process, the connecting portion of the second conductive component is inserted into the through hole of the first conductive component.

[0126] The seam-sealing process involves seaming the end of the connecting portion at the edge of the through hole in the first conductive component to form a seam portion; and

[0127] The welding process involves welding the aforementioned seam portion to the aforementioned first conductive component by irradiating it with energy rays.

[0128] In the above welding process, the energy line is irradiated with a gap between the first conductive component and the second conductive component on the inner side of the portion of the energy line being irradiated.

[0129] The above welding process includes:

[0130] The first welding process involves irradiating a first region with the aforementioned energy lines to form a first welding region; and

[0131] In the second welding process, the energy lines are irradiated onto the second region to form a second welding region with a welding depth smaller than that of the first welding region.

[0132] Item 8: According to the manufacturing method described in Item 7, wherein,

[0133] The aforementioned energy storage device also has a housing to house the aforementioned electrodes.

[0134] The aforementioned housing has terminal mounting holes.

[0135] The second conductive component is a terminal that is inserted into the terminal mounting hole.

[0136] Item 9: According to the manufacturing method described in Item 7 or 8, wherein,

[0137] The first conductive component described above has a recess.

[0138] The aforementioned through hole is provided on the bottom surface of the aforementioned recess.

[0139] The aforementioned slit portion is disposed within the aforementioned recess.

[0140] The gap is located between the bottom surface of the recess, the side surface of the recess, and the constricted joint.

[0141] Item 10: According to the manufacturing method described in Item 9, wherein,

[0142] A tapered portion is provided on the inner wall of the aforementioned through hole, which is connected to the bottom surface of the aforementioned recess and inclined from the bottom surface.

[0143] Item 11: According to any one of the manufacturing methods described in items 7 to 10, wherein,

[0144] In the surface of the first conductive component where the aforementioned slit portion is provided, a groove is provided around the slit portion.

[0145] Item 12: According to any one of the manufacturing methods described in items 7 to 11, wherein,

[0146] In the above welding process, the first welding process and the second welding process are performed alternately to alternately set the first welding area and the second welding area in the circumferential direction of the seam.

[0147] Item 13: According to any one of the manufacturing methods described in items 7 to 12, wherein,

[0148] In the above welding process, the first welding process is performed on the first region including the welding start point, and the second welding process is performed immediately following the first welding process.

[0149] Item 14: According to any one of the manufacturing methods described in items 7 to 12, wherein,

[0150] The welding process begins with the second welding process performed on the second region containing the welding start point, and the first welding process is performed immediately following the second welding process.

Claims

1. An energy storage device, characterized in that, have: An electrode body, comprising a positive electrode and a negative electrode; The first conductive component is electrically connected to either the positive or negative electrode; and The second conductive component is electrically connected to the first conductive component. The aforementioned first conductive component includes a through hole. The second conductive component mentioned above includes: The connecting part is inserted into the aforementioned through hole; and A converging slit is provided at the end of the connecting portion and is converging slit at the edge of the through hole of the first conductive member. The aforementioned seam portion is provided with a welding portion for welding the first conductive component and the second conductive component. There is a gap between the first conductive component and the second conductive component on the inner side of the welded part. The weld portion provided at the aforementioned seam has a first weld area and a second weld area with a weld depth smaller than that of the first weld area.

2. The energy storage device according to claim 1, characterized in that, The aforementioned energy storage device also has a housing to house the aforementioned electrodes. The aforementioned housing has terminal mounting holes. The second conductive component is a terminal that is inserted into the terminal mounting hole.

3. The energy storage device according to claim 1 or 2, characterized in that, The first conductive component described above has a recess. The aforementioned through hole is provided on the bottom surface of the aforementioned recess. At least a portion of the aforementioned slit portion is disposed within the aforementioned recess. The gap is located between the bottom surface of the recess, the side surface of the recess, and the constricted joint.

4. The energy storage device according to claim 3, characterized in that, A tapered portion is provided on the inner wall of the aforementioned through hole, which is connected to the bottom surface of the aforementioned recess and inclined from the bottom surface.

5. The energy storage device according to claim 1 or 2, characterized in that, In the surface of the first conductive component where the aforementioned slit portion is provided, a groove is provided around the slit portion.

6. The energy storage device according to claim 1 or 2, characterized in that, The first welding area and the second welding area are alternately arranged in the circumferential direction of the aforementioned seam.

7. A manufacturing method for an energy storage device comprising an electrode body including a positive electrode and a negative electrode, characterized in that, Include: The preparation process includes preparing a first conductive component with a through hole that is electrically connected to the positive or negative electrode of the electrode body, and a second conductive component with a connection portion that is electrically connected to the first conductive component. In the insertion process, the connecting portion of the second conductive component is inserted into the through hole of the first conductive component. The seam-sealing process involves seaming the end of the connecting portion at the edge of the through hole in the first conductive component to form a seam portion; and The welding process involves welding the aforementioned seam portion to the aforementioned first conductive component by irradiating it with energy rays. In the above welding process, the energy line is irradiated with a gap between the first conductive component and the second conductive component on the inner side of the portion of the energy line being irradiated. The above welding process includes: The first welding process involves irradiating a first region with the aforementioned energy lines to form a first welding region; and In the second welding process, the energy lines are irradiated onto the second region to form a second welding region with a welding depth smaller than that of the first welding region.

8. The manufacturing method according to claim 7, characterized in that, The aforementioned energy storage device also has a housing to house the aforementioned electrodes. The aforementioned housing has terminal mounting holes. The second conductive component is a terminal that is inserted into the terminal mounting hole.

9. The manufacturing method according to claim 7 or 8, characterized in that, The first conductive component described above has a recess. The aforementioned through hole is provided on the bottom surface of the aforementioned recess. The aforementioned slit portion is disposed within the aforementioned recess. The gap is located between the bottom surface of the recess, the side surface of the recess, and the constricted joint.

10. The manufacturing method according to claim 9, characterized in that, A tapered portion is provided on the inner wall of the aforementioned through hole, which is connected to the bottom surface of the aforementioned recess and inclined from the bottom surface.

11. The manufacturing method according to claim 7 or 8, characterized in that, In the surface of the first conductive component where the aforementioned slit portion is provided, a groove is provided around the slit portion.

12. The manufacturing method according to claim 7 or 8, characterized in that, In the above welding process, the first welding process and the second welding process are performed alternately to alternately set the first welding area and the second welding area in the circumferential direction of the seam.

13. The manufacturing method according to claim 7 or 8, characterized in that, In the above welding process, the first welding process is performed on the first region including the welding start point, and the second welding process is performed immediately following the first welding process.

14. The manufacturing method according to claim 7 or 8, characterized in that, The welding process begins with the second welding process performed on the second region containing the welding start point, and the first welding process is performed immediately following the second welding process.

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