Terminal for power storage device, and power storage device

Abstract

The invention relates to a terminal for a power storage device and a power storage device. This negative electrode terminal is provided with a first conductive member comprising a first metal, and a second conductive member comprising a second metal different from the first metal. The second conductive member has a flange portion and a shaft portion provided on one surface of the flange portion. The second conductive member has, on the upper surface of the flange portion, a first metal bonding portion that is metal-bonded to the first conductive member. The second conductive member has a protrusion at a position closer to the outer peripheral side than the first metal bonding portion. The first conductive member has a first recess that fits into the protrusion. The second conductive member has a second metal bonding portion that metal-bonds the first conductive member and the second conductive member in the first recess and the protrusion.

Description

Technical Field

[0001] The present invention relates to a terminal for an electricity storage device and an electricity storage device. Background Art

[0002] Japanese Patent Application Publication No. 2022-049726 discloses a terminal including a plate-shaped first metal component and a metal second component ultrasonically welded to one surface of the first component. A recess is formed on the surface of the first component opposite to the surface to which the second component is welded. The first component and the second component are ultrasonically welded in the recess.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-049726 Summary of the invention

[0004] The present inventors have considered trying to further improve the reliability of the connection portion between the components in a terminal for a power storage device to which a plurality of components are connected.

[0005] The terminal for a storage device disclosed herein includes a first conductive component made of a first metal and a second conductive component made of a second metal different from the first metal. The second conductive component has a flange portion and a shaft portion provided on one surface of the flange portion. The second conductive component has a first metal joint portion on the upper surface of the flange portion that is metal-bonded to the first conductive component. The second conductive component has at least one of a first recess and a protrusion at a position closer to the outer peripheral side than the first metal joint portion. The first conductive component has the first recess and the other of the protrusion that are engaged with at least one of the first recess and the protrusion. The second conductive component has a second metal joint portion that metal-bonds the first conductive component to the second conductive component at the first recess and the protrusion.

[0006] The reliability of the connection portion between the first conductive member and the second conductive member of the power storage device terminal is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a perspective view of the power storage device 100 .

[0008] Figure 2 It is along Figure 1 A schematic longitudinal cross-sectional view taken along line II-II.

[0009] Figure 3 It is a cross-sectional view showing the negative electrode terminal 40 attached to the sealing plate 24 .

[0010] Figure 4 It is a perspective view showing the battery pack 200 .

[0011] Figure 5 is a schematic diagram of the external conductive component 48.

[0012] Figure 6 It is a perspective view of the second conductive member 42 .

[0013] Figure 7 is a schematic diagram of the protrusion 42p.

[0014] Figure 8 It is a schematic diagram of a protrusion 42p involved in another embodiment.

[0015] Fig. 9 It is a cross-sectional view of the negative electrode terminal 40 .

[0016] Fig.10 It is a cross-sectional view of a negative electrode terminal 40A according to another embodiment.

[0017] Fig.11 It is a cross-sectional view of a negative electrode terminal 40B according to another embodiment.

[0018] Fig.12 It is a cross-sectional view of a negative electrode terminal 40C according to another embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, an embodiment of the technology disclosed herein will be described with reference to the accompanying drawings. The embodiments described here are of course not intended to specifically limit the present invention. The drawings are schematically depicted and do not necessarily reflect the actual objects. In addition, the same figure marks are appropriately marked for components and parts that play the same role, and repeated descriptions are appropriately omitted. In the following description, the figure marks L, R, F, Rr, U, and D in the drawings represent left, right, front, back, top, and bottom, and the figure marks X, Y, and Z in the drawings represent the long side direction, short side direction, and height direction of the power storage device, respectively. However, these are just directions for the convenience of description and do not limit the setting form of the power storage device in any way.

[0020] In addition, in this specification, "power storage device" refers to the term for all power storage devices that can extract electrical energy. In addition to secondary batteries that can be repeatedly charged and discharged by moving charge carriers between a pair of electrodes (positive and negative electrodes) via electrolytes, power storage devices also include capacitors such as double-layer capacitors. Below, with respect to the manufacturing method of the power storage device, an embodiment of the case where a lithium-ion secondary battery is used as the object is described.

[0021] <Electricity Storage Device 100>

[0022] Figure 1 It is a perspective view of the power storage device 100 . Figure 2 It is along Figure 1 A schematic longitudinal cross-sectional view of line II-II. Figure 2 In the figure, the gasket 50 and the insulator 60 are omitted. Figure 3 It is a cross-sectional view showing the negative electrode terminal 40 attached to the sealing plate 24 . Figure 4 2 is a perspective view showing the battery pack 200. Figure 4 , a mode in which the power storage device 100 disclosed here is used as a single cell and a plurality of power storage devices 100 are connected in series via a bus bar 90 is illustrated.

[0023] like Figure 2 As shown, the power storage device 100 includes an electrode body 10, a housing 20, a positive terminal 30, and a negative terminal 40. The power storage device 100 may also include an external conductive component 48. The power storage device 100 is characterized by having the positive terminal 30 and / or the negative terminal 40 disclosed here, and the structure other than this may be the same as before. The power storage device 100 is preferably a secondary battery, and more preferably a non-aqueous electrolyte secondary battery. Preferably, the power storage device 100 is a square secondary battery. Here, the power storage device 100 is a lithium-ion secondary battery. Although not shown in the figure, the power storage device 100 also includes an electrolyte. The power storage device 100 is composed of the electrode body 10 and the electrolyte not shown in the figure housed in the housing 20.

[0024] The electrode body 10 may be the same as in the past and is not particularly limited. The electrode body 10 includes a positive electrode and a negative electrode (not shown). The electrode body 10 is, for example, a flat wound electrode body in which a strip-shaped positive electrode and a strip-shaped negative electrode are stacked in an insulated state with a strip-shaped separator interposed therebetween and wound around a winding axis. However, in other embodiments, the electrode body 10 may also be a stacked electrode body in which a square (typically rectangular) positive electrode and a square (typically rectangular) negative electrode are stacked in an insulated state.

[0025] The positive electrode has a positive electrode collector 11 and a positive electrode mixture layer (not shown) fixed on the positive electrode collector 11. The positive electrode collector 11 is composed of, for example, a conductive metal such as aluminum, an aluminum alloy, nickel, and stainless steel. The positive electrode mixture layer contains a positive electrode active material (for example, a lithium transition metal composite oxide). The negative electrode has a negative electrode collector 12 and a negative electrode mixture layer (not shown) fixed on the negative electrode collector 12. The negative electrode collector is composed of, for example, a conductive metal such as copper, a copper alloy, nickel, and stainless steel. The negative electrode mixture layer contains a negative electrode active material (for example, a carbon material such as graphite).

[0026] As in Figure 2As indicated by the oblique lines in the figure, in the central part of the long side direction X of the electrode body 10, there is formed a stacked portion in which the positive electrode mixture layer and the negative electrode mixture layer are stacked in an insulated state. On the other hand, at the left end part of the long side direction X of the electrode body 10, a part of the positive electrode collector 11 (the positive electrode collector exposed portion) on which the positive electrode mixture layer is not formed extends from the stacked portion. A positive electrode collector component 13 is attached to the positive electrode collector exposed portion. The positive electrode collector component 13 can also be made of the same metal material as the positive electrode collector 11, such as conductive metals such as aluminum, aluminum alloy, nickel, and stainless steel. The positive electrode collector component 13 is arranged in the outer casing 20. The positive electrode collector component 13 electrically connects the positive electrode to the positive terminal 30.

[0027] In addition, at the right end of the electrode body 10 in the long side direction X, a part of the negative electrode collector 12 (the exposed part of the negative electrode collector) where the negative electrode mixture layer is not formed extends from the stacked part. A negative electrode collector component 14 is attached to the exposed part of the negative electrode collector. The material (metal type) of the negative electrode collector component 14 can be different from that of the positive electrode collector component 13. The negative electrode collector component 14 can also be composed of the same metal type as the negative electrode collector 12, such as conductive metals such as copper, copper alloy, nickel, and stainless steel. The negative electrode collector component 14 is arranged in the outer shell 20. The negative electrode collector component 14 electrically connects the negative electrode to the negative terminal 40. The negative electrode collector component 14 electrically connects the negative electrode to the negative terminal 40 inside the outer shell 20.

[0028] The electrolyte can be the same as before and there is no particular limitation. The electrolyte is, for example, a non-aqueous liquid electrolyte (non-aqueous electrolyte) containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent includes, for example, carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. The supporting salt is, for example, a fluorine-containing lithium salt such as LiPF6. However, the electrolyte can also be integrated with the electrode body 10 in a solid state (solid electrolyte).

[0029] The outer shell 20 is a shell that contains the electrode body 10. Here, the outer shell 20 is formed into a flat and bottomed cubic shape (square). However, the shape of the outer shell 20 is not limited to a square, and can be any shape such as a cylinder. The material of the outer shell 20 can be the same as the material used in the past, and there is no special restriction. The outer shell 20 is made of a light metal material with good thermal conductivity, such as aluminum, aluminum alloy, and stainless steel. The outer shell 20 includes an outer body 22 having an opening 22h, and a sealing plate 24 that blocks the opening 22h. Preferably, the outer shell 20 includes an outer body 22 and a sealing plate 24. The outer shell 20 is integrated by joining (for example, welding) the sealing plate 24 to the periphery of the opening 22h of the outer body 22. The outer shell 20 is hermetically sealed (sealed).

[0030] The outer casing 22 has a bottom surface 22d. The sealing plate 24 is opposite to the bottom surface 22d of the outer casing 22. The sealing plate 24 is mounted on the outer casing 22 in such a manner as to block the opening 22h of the outer casing 22. Here, the sealing plate 24 is substantially rectangular. In addition, in this specification, "substantially rectangular" is a term that includes, in addition to a complete rectangular shape (rectangle), a shape in which the corners connecting the long sides and the short sides of the rectangle are arc-shaped, a shape having a cutout at the corner, and the like.

[0031] The positive terminal 30 and the negative terminal 40 protrude to the outside of the outer shell 20. Here, the positive terminal 30 and the negative terminal 40 protrude from the same surface of the outer shell 20 (specifically, the sealing plate 24). However, the positive terminal 30 and the negative terminal 40 may protrude from different surfaces of the outer shell 20. The positive terminal 30 and the negative terminal 40 are respectively arranged at both end portions of the sealing plate 24 in the long side direction X. The positive terminal 30 and / or the negative terminal 40 are an example of a "terminal for a storage device".

[0032] like Figure 2 As shown, the positive terminal 30 is electrically connected to the positive electrode of the electrode body 10 via the positive electrode collector 13 inside the outer shell 20. The negative terminal 40 is electrically connected to the negative electrode of the electrode body 10 via the negative electrode collector 14 inside the outer shell 20. The positive terminal 30 and the negative terminal 40 are respectively mounted on the outer shell 20 (specifically, the sealing plate 24). Preferably, the positive terminal 30 and the negative terminal 40 are fixed to the outer shell 20 (specifically, the sealing plate 24). The positive terminal 30 and the negative terminal 40 are respectively separated by a gasket 50 (refer to Figure 3 ) and insulator 60 (refer to Figure 3 ) is insulated from the sealing plate 24.

[0033] Hereinafter, the structure of the positive terminal 30 and the negative terminal 40 of the power storage device 100 will be described in detail by taking the terminal structure on the side of the negative terminal 40 as an example. The terminal structure described below is preferably provided on the negative terminal 40 side. In addition, the terminal structure described below may be provided on the positive terminal 30 side, or may be provided on both the positive terminal 30 side and the negative terminal 40 side. In this case, in the following description, the part of "negative electrode" can be appropriately replaced with "positive electrode".

[0034] like Figure 3As shown, a terminal mounting hole 24h is formed in the sealing plate 24 and passes through in the up-down direction Z. The terminal mounting hole 24h is provided in the housing 20 (in this embodiment, the sealing plate 24). Preferably, a negative terminal 40 is inserted into the terminal mounting hole 24h. Although not shown in the figure, here, the terminal mounting hole 24h is circular (e.g., a perfect circle) in a top view. The terminal mounting hole 24h has an inner diameter of a size that can be inserted through a rivet portion 40c of the negative terminal 40 described later before riveting processing. The terminal mounting hole 24h is formed to be smaller than the flange portion 42f of the negative terminal 40 described later.

[0035] The negative electrode current collector component 14 is attached to the negative electrode current collector exposed portion of the negative electrode current collector 12, and constitutes a conduction path that electrically connects the negative electrode to the negative terminal 40. The negative electrode current collector component 14 has a flat plate-shaped portion 14f extending horizontally along the inner surface of the sealing plate 24. In the flat plate-shaped portion 14f, an opening 14h is provided at a position corresponding to the terminal mounting hole 24h. The opening 14h has an inner diameter of a size that can be inserted through the rivet portion 40c of the negative terminal 40 described later before the rivet processing. The negative electrode current collector component 14 is fixed to the sealing plate 24 together with the negative terminal 40 by rivet processing. It is preferred that a resin insulating component is arranged between the housing 20 (in this embodiment, the sealing plate 24) and the negative electrode current collector component 14. In this embodiment, the negative electrode current collector component 14 is fixed to the sealing plate 24 together with the negative terminal 40 in an insulated state separated by the insulator 60.

[0036] The gasket 50 is an insulating member disposed between the upper surface (outer surface) of the sealing plate 24 and the negative terminal 40. An insulating member (e.g., gasket 50) is preferably disposed between the housing 20 (e.g., the sealing plate 24) and the negative terminal 40. Here, the gasket 50 has the function of insulating the sealing plate 24 from the negative terminal 40 and sealing the terminal mounting hole 24h. The gasket 50 is made of an electrically insulating and elastically deformable resin material, such as a fluorinated resin such as a perfluoroalkoxy fluorine resin (PFA), a polyphenylene sulfide resin (PPS), an aliphatic polyamide, and the like.

[0037] The gasket 50 has a barrel 51 and a base 52. The barrel 51 is a part that prevents direct contact between the sealing plate 24 and the rivet portion 40c of the negative terminal 40. The barrel 51 is a hollow cylindrical shape. The barrel 51 has a hole 51h that penetrates in the up-down direction Z. The hole 51h is formed so as to be able to insert the rivet portion 40c of the negative terminal 40 before the rivet processing. The barrel 51 is inserted into the terminal mounting hole 24h of the sealing plate 24. The base 52 is a part that prevents direct contact between the sealing plate 24 and the flange portion 42f of the negative terminal 40 described later. The base 52 is connected to the upper end of the barrel 51. The base 52 extends in the horizontal direction from the upper end of the barrel 51. The base 52 is formed in a circular ring shape, for example, in a manner that surrounds the terminal mounting hole 24h of the sealing plate 24. The base 52 extends along the upper surface of the sealing plate 24. The base portion 52 is sandwiched between the lower surface 42 d of the flange portion 42 f of the negative electrode terminal 40 and the upper surface of the sealing plate 24 , and is compressed in the up-down direction Z by caulking.

[0038] The insulator 60 is an insulating component disposed between the lower surface (inner surface) of the sealing plate 24 and the negative electrode current collecting component 14. It is preferred that an insulating component (such as the insulator 60) is disposed between the housing 20 (such as the sealing plate 24) and the negative electrode current collecting component 14. The insulator 60 has a flat plate-shaped portion extending horizontally along the inner surface of the sealing plate 24. In the flat plate-shaped portion, a hole portion 60h is formed at a position corresponding to the terminal mounting hole 24h. The hole portion 60h has an inner diameter of a size that can be inserted through the shaft portion 42s of the negative terminal 40. The insulator 60 is composed of a resin material that has resistance and electrical insulation to the electrolyte used and can be elastically deformed, such as a fluorinated resin such as a perfluoroalkoxy fluorine resin (PFA), a polyphenylene sulfide resin (PPS), etc. The flat plate portion of the insulator 60 is sandwiched between the lower surface of the sealing plate 24 and the upper surface of the negative electrode current collecting component 14, and is compressed in the up and down direction Z by riveting.

[0039] <Negative terminal 40>

[0040] The negative electrode terminal 40 includes a first conductive component 41 and a second conductive component 42. Figure 3 As shown, the negative electrode terminal 40 is inserted through the terminal mounting hole 24h and extends from the inside to the outside of the case 20. The negative electrode terminal 40 may further include an external conductive member 48 connected to the first conductive member 41 outside the case 20.

[0041] In the negative electrode terminal 40 , two types of conductive members, ie, a first conductive member 41 and a second conductive member 42 are electrically connected to each other via metal joints 45 and 46 .

[0042] The negative terminal 40 is inserted into the terminal mounting hole 24h of the sealing plate 24 and the opening 14h of the negative current collecting component 14, and the front end portion in the insertion direction is riveted to the negative current collecting component 14. In detail, it is riveted to the peripheral portion surrounding the opening 14h of the negative current collecting component 14. A rivet portion 40c is formed at the lower end of the negative terminal 40. The negative terminal 40 is fixed to the sealing plate 24 by riveting and is electrically connected to the negative current collecting component 14. Here, the rivet portion 40c is cylindrical. However, the shape of the rivet portion 40c is not limited to a cylindrical shape, and can also be an arbitrary shape such as a columnar shape. In addition, it is preferred that the rivet portion 40c is welded to the negative current collecting component 14. Below, the first conductive component 41 and the second conductive component 42 constituting the negative terminal 40 are described.

[0043] <First Conductive Member 41 >

[0044] The first conductive component 41 is a component disposed outside the housing 20. The first conductive component 41 is made of a first metal. The first metal is, for example, a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. Preferably, the first metal is aluminum or an aluminum alloy. Here, the first conductive component 41 is made of aluminum. Preferably, the first conductive component 41 is made of a (soft) metal having a Vickers hardness less than that of the second conductive component 42. The first conductive component 41 may also be the same metal as the positive electrode current collecting component 13, or an alloy having the same metal element as the first component (the component having the highest proportion in terms of mass ratio. The same applies hereinafter).

[0045] The diameter of the first conductive component 41 is preferably greater than the thickness. In this embodiment, the first conductive component 41 is plate-shaped (specifically, a flat plate). The first conductive component 41 is preferably roughly disk-shaped in a top view. The first conductive component 41 has a first surface 41a and a second surface 41b. The first surface 41a is a surface bonded to the second conductive component 42.

[0046] The second surface 41b is a surface on the opposite side to the first surface 41a. In this embodiment, an annular rib 41ri is formed on the second surface 41b of the first conductive component 41. The rib 41ri can be continuously formed into a circular ring shape. On the second surface 41b, an external conductive component 48 is welded and joined via the rib 41ri. Preferably, the external conductive component 48 extends along the long side direction of the sealing plate 24. Preferably, the external conductive component 48 is made of the same type of metal as the first conductive component 41 (in this embodiment, aluminum or aluminum alloy).

[0047] like Figure 4 As shown, when manufacturing the battery pack 200 , the bus bar 90 is connected to the external conductive member 48 connected to the first conductive member 41 . Figure 5 is a schematic diagram of the external conductive component 48. Figure 5, the external conductive member 48 and the bus bar 90 are schematically shown as viewed from the upper surface. Figure 5 In FIG. 4 , the second conductive component 42 hidden in the external conductive component 48 is indicated by a dotted line. Figure 5 As shown, the bus bar 90 is connected to the external conductive member 48 at the bus bar welding portion 48a. The bus bar 90 and the external conductive member 48 can be welded by laser welding or the like. In addition, it is also possible to configure such that the external conductive member 48 is not necessarily mounted on the second surface 41b of the first conductive member 41. Figure 4 ), the bus bar 90 may be directly connected to the first conductive member 41 without passing through the external conductive member 48 .

[0048] <Second Conductive Member 42 >

[0049] like Figure 3 As shown, the second conductive component 42 is a component that extends from the inside to the outside of the housing 20 by inserting through the terminal mounting hole 24h. The second conductive component 42 is made of a second metal different from the first metal. The second metal is, for example, a conductive metal such as copper, a copper alloy, nickel, stainless steel, iron, and an iron alloy. Preferably, the second metal is made of copper or a copper alloy. Here, the second conductive component 42 is made of copper. Preferably, the second conductive component 42 is made of a (hard) metal having a Vickers hardness greater than that of the first conductive component 41. The second metal may also be the same metal as the negative electrode current collecting component 14, or an alloy having the same metal element as the first component. The second conductive component 42 may also be coated with other metals on a part or all of its surface by Ni plating, tin plating, etc.

[0050] The second conductive component 42 has a flange portion 42f and a shaft portion 42s (connecting portion). The shaft portion 42s is a portion connected to the negative electrode current collector component 14 and becomes a rivet portion 40c. The shaft portion 42s is provided on one surface of the flange portion 42f (in this embodiment, the lower surface 42d). The shaft portion 42s is a portion inserted through the terminal mounting hole 24h of the housing 20 (in this embodiment, the sealing plate 24) and the opening 14h of the negative electrode current collector component 14. A base 52 of a gasket 50 is arranged between the flange portion 42f and the sealing plate 24. A barrel portion 51 of a gasket 50 is arranged between the shaft portion 42s and the sealing plate 24. The shaft portion 42s is enlarged toward the front end. The enlarged portion is connected to the negative electrode current collector component 14. The enlarged diameter portion is also called a caulking portion 40c, and is preferably connected to the negative current collecting member 14 by caulking while being inserted into the opening 14h of the negative current collecting member 14. From the viewpoint of improving conductivity, the caulking portion 40c is preferably joined to a portion of the negative current collecting member 14 by laser welding or the like.

[0051] The flange portion 42f is a portion having a larger diameter than the shaft portion 42s in the plane direction (X direction and Y direction). In other words, the flange portion 42f is a portion having a larger diameter at one end of the shaft portion 42s than the shaft portion 42s. The flange portion 42f is a portion disposed outside the housing 20. The flange portion 42f is connected to the first conductive member 41.

[0052] The shape of the flange portion 42f is not particularly limited. In a top view along the direction (height direction) in which the shaft portion 42s extends, the flange portion 42f may be, for example, roughly circular or roughly polygonal. Preferably, the flange portion 42f is roughly circular in a top view. The roughly circular shape is not limited to a completely circular shape, and includes a shape in which a cutout is formed in a portion of the outer peripheral surface. Preferably, at least a portion of the outer periphery of the flange portion 42f is circular. For example, preferably, in the thickness direction of the flange portion 42f, the shape of the outer periphery that surrounds the same height is circular.

[0053] The flange portion 42f has a large diameter portion 42fa and a small diameter portion 42fb. The large diameter portion 42fa is a portion having a larger outer diameter than the small diameter portion 42fb. The large diameter portion 42fa is a roughly disc-shaped portion having substantially the same diameter in the thickness direction (height direction). In other words, the outer peripheral edge of the upper surface 42u of the large diameter portion 42fa is circular. A small diameter portion 42fb protruding upward is formed in the approximate center of the upper surface 42u of the large diameter portion 42fa. The small diameter portion 42fb is shaped along the second recess 41R. The diameter of the small diameter portion 42fb increases as it moves toward the front end side (the side away from the flange portion 42f). The diameter of the small diameter portion 42fb decreases as it moves from the front end toward the base end. In addition, the diameter of the small diameter portion 42fb may also be smaller than the diameter of the shaft portion 42s.

[0054] In addition, the outer diameter of the large diameter portion 42fa and the small diameter portion 42fb refers to the outer shape of the portion with the largest diameter from the central axis CL in each portion. In this embodiment, the outer diameter of the small diameter portion 42fb refers to the outer diameter of the upper surface 42u1 on the front end side of the small diameter portion 42fb. In this embodiment, the outer diameter of the large diameter portion 42fa is substantially constant in the axial direction, and therefore refers to the outer diameter at any position in the axial direction.

[0055] The negative terminal 40 has a contact portion C where the first conductive component 41 contacts the second conductive component 42. In this embodiment, a portion of the flange portion 42f of the second conductive component 42 contacts the first conductive component 41 in the first recess 41r. At the contact portion C, the second conductive component 42 has a first metal joint portion 45 and a second metal joint portion 46. The first metal joint portion 45 and the second metal joint portion 46 are joint portions where the first conductive component 41 and the second conductive component 42 are joined by metal joining. The first metal joint portion 45 is formed on the upper surface of the flange portion 42f at a position closer to the center than the second metal joint portion 46. Thus, it is possible to reduce the degradation of the first metal joint portion 45 due to the load applied by the electrolyte, the external connection component, and the like.

[0056] In this embodiment, the first metal joint 45 is formed on the upper surface 42u1 of the small diameter portion 42fb. From the viewpoint of suppressing corrosion caused by electrolyte or water, etc., it is preferred that the first metal joint 45 connects the upper surface of the flange portion 42f with the bottom surface of the recessed portion of the first conductive member 41 (in this embodiment, the first bottom surface 41R1 of the second recessed portion 41R described later (see Fig. 9 More preferably, the first metal joining portion 45 is formed in the center portion of the upper surface of the flange portion 42f.

[0057] Here, metal bonding refers to bonding a plurality of metal parts to each other by metallurgical bonding, excluding bonding based on mechanical fastening. Preferably, the metal bonding parts 45 and 46 are formed by ultrasonic bonding, diffusion bonding, laser welding, etc. From the viewpoint of suppressing the formation of fragile intermetallic compounds at the bonding interface, preferably, the metal bonding parts 45 and 46 are ultrasonic bonding parts formed by ultrasonic bonding. In this embodiment, the metal bonding parts 45 and 46 are ultrasonic bonding parts that bond the first conductive component 41 and the second conductive component 42 by ultrasonic bonding.

[0058] The second conductive member 42 has a protrusion 42p on the outer peripheral side of the first metal joint 45. The protrusion 42p is provided at the contact portion C between the first conductive member 41 and the second conductive member 42. In this embodiment, the protrusion 42p is formed on the upper surface 42u of the large diameter portion 42fa of the upper surface of the flange portion 42f.

[0059] Figure 6 It is a perspective view of the second conductive member 42 . Figure 7 is a schematic diagram of the protrusion 42p. Figure 8 FIG. 4 is a schematic diagram of a protrusion 42p according to another embodiment. Figure 6As shown, the protrusion 42p is arranged near the small diameter portion 42fb on the upper surface 42u of the large diameter portion 42fa. The protrusion 42p can be connected to the small diameter portion 42fb or can be away from the small diameter portion 42fb. In this embodiment, the protrusion 42p is connected to the small diameter portion 42fb and is arranged to extend radially from the base end of the small diameter portion 42fb.

[0060] like Figure 7 As shown in FIG. 1 , the front end of the protrusion 42p is flat. The cross section of the protrusion 42p along the length direction (radial direction of the flange portion 42f) is substantially trapezoidal. The shape of the protrusion 42p is not limited to this form. Figure 8 As shown, the shape of the front end may be pointed. The cross section of the protrusion 42p along the length direction may also be roughly triangular. The size and shape of the protrusion 42p are not particularly limited. From the perspective of the durability of the protrusion 42p, the aspect ratio A / B represented by the height B of the protrusion 42p relative to the width A of the base end of the protrusion 42p is preferably 1 or more.

[0061] like Figure 6 and Figure 7 As shown, the protrusion 42p is formed along the radial direction of the flange portion 42f. The length of the protrusion 42p in the radial direction is not particularly limited. For example, the length of the protrusion 42p in the radial direction is preferably 0.25 mm or more, and more preferably 0.5 mm or more. In addition, the length of the protrusion 42p in the radial direction is preferably 5 mm or less, and more preferably 3 mm or less.

[0062] like Figure 5 As shown, six protrusions 42p are provided on the upper surface 42u of the large diameter portion 42fa of the flange portion 42f. The six protrusions 42p are provided at substantially the same distance from the central portion in the radial direction. As for the spacing of the protrusions 42p, for example, they can be provided at substantially equal intervals in the circumferential direction. In addition, the number, configuration, spacing, etc. of the protrusions 42p are not particularly limited. The number of protrusions 42p may also be one. From the viewpoint of improving the conductivity between the first conductive component 41 and the second conductive component 42, the number of protrusions 42p is preferably multiple, and more preferably 4 or more. From the viewpoint of productivity, the number of protrusions 42p may be, for example, less than 20, less than 12, or less than 8.

[0063] Fig. 9 is a cross-sectional view of the negative terminal 40. Fig. 9 , a cross section near the interface between the first conductive component 41 and the second conductive component 42 is shown. Fig. 9 In the figure, the sealing plate 24, the gasket 50, the insulator 60, the negative electrode current collecting component 14, etc. are omitted. Fig. 9As shown, the protrusion 42p of the second conductive component 42 is embedded in the first conductive component 41. In other words, the first conductive component 41 has a first recess 41r that is embedded with the protrusion 42p of the second conductive component 42. The first conductive component 41 has the same number of first recesses 41r as the protrusion 42p of the second conductive component 42. The first recesses 41r are formed at the same position as the protrusion 42p in a shape corresponding to the protrusion 42p. Preferably, a plurality of first recesses 41r and protrusions 42p are provided, respectively. The above-mentioned second metal bonding portion 46 is formed by metal bonding the first conductive component 41 and the second conductive component 42 at the first recess (in this embodiment, the first recess 41r of the first conductive component 41) and the protrusion (in this embodiment, the protrusion 42p of the second conductive component 42). Therefore, the first metal joining portion 45 formed on the upper surface 42u1 of the small diameter portion 42fb and the second metal joining portion 46 formed on the upper surface 42u of the large diameter portion 42fa are formed at different positions in the direction in which the shaft portion 42s extends.

[0064] The second metal joint 46 is not particularly limited as long as it is formed on the outer peripheral side of the first metal joint 45. In this embodiment, the first metal joint 45 is formed on the central axis CL of the negative terminal 40 (shaft portion 42s). The second metal joint 46 is formed at a position away from the central axis CL. However, it is not limited to this form. The first metal joint 45 and the second metal joint 46 may also be connected. The first metal joint 45 and the second metal joint 46 may also be formed on the same plane. Between the first metal joint 45 and the second metal joint 46, there may also be an area that is not joined by metal joining.

[0065] In addition, when the power storage device moves or vibrates during use, a load may be applied to the terminal connected to the external connection component such as the bus bar. In the case where the terminal is formed by metal bonding of multiple conductive components, the load applied to the terminal via the external connection component may also act on the bonding interface of the multiple conductive components. For example, in the case where the bus bar moves in the circumferential direction relative to the central axis of the terminal, a force may be applied to the conductive component connected to the bus bar among the multiple conductive components in the direction of rotation with the above-mentioned central axis as the axis. As a result, a load may also be applied to the metal bonding portion. According to the understanding of the inventors, if a load is applied to the metal bonding portion, there is a concern that the bonding interface of the metal bonding portion will peel off and the bonding area in the bonding interface will decrease. In such a case, there is a concern that the conduction between the multiple conductive components constituting the terminal will be reduced.

[0066] In the above-mentioned embodiment, the second conductive member 42 has the first metal joint portion 45 metal-joined with the first conductive member 41 on the upper surface of the flange portion 42f. Thus, the conductivity between the first conductive member 41 and the second conductive member 42 is good. The second conductive member 42 has a protrusion 42p that fits with the first recess 41r of the first conductive member 41 on the outer peripheral side of the first metal joint portion 45. According to this structure, for example, even if the external connecting member such as the bus bar 90 acts in the circumferential direction with the central axis CL of the negative terminal 40 as an axis, since the protrusion 42p fits with the first recess 41r, it is difficult for a load to act in a direction that rotates the first conductive member 41 relative to the second conductive member 42. Thus, the first metal joint portion 45 is easily maintained, and the conductivity reliability between the first conductive member 41 and the second conductive member 42 in the negative terminal 40 is good. In addition, the second metal joint portion 46 is formed on the first recess 41r and the protrusion 42p. As a result, the conduction between the first conductive component 41 and the second conductive component 42 is better. In addition, when the first conductive component 41 of the negative terminal 40 is directly connected to an external connection component, or when the first conductive component 41 is connected to an external connection component via the external conductive component 48, the effect of reducing the load acting on the first metal joint 45 is achieved.

[0067] In addition, the greater the distance between the central axis CL of the negative terminal 40 and the connection portion of the external connection component, the greater the load applied to the terminal via the external connection component. Therefore, when the negative terminal 40 is connected to the external conductive component 48 and the external conductive component 48 is connected to the external connection component, the effect of reducing the load applied to the first metal junction 45 can be further increased.

[0068] In the above-mentioned embodiment, the second conductive component 42 has a protrusion 42p. The first conductive component 41 has a first recess 41r for the protrusion 42p to fit in. However, it is not limited to this form. It is sufficient that at least one of the first conductive component and the second conductive component is provided with a protrusion, and the other is provided with a first recess. For example, it is also possible to be configured such that the first conductive component has a protrusion, and the second conductive component has a first recess that fits in with the protrusion. In addition, both the first conductive component and the second conductive component may have protrusions. In this case, the first conductive component and the second conductive component may each have a first recess that fits in with the protrusion of the other.

[0069] However, from the viewpoint of fitting the protrusion provided on one conductive member with the other conductive member, it is preferable that the conductive member made of metal with a larger Vickers hardness be provided in the first conductive member 41 and the second conductive member 42. From this viewpoint, it is preferable that the second conductive member 42 has at least the protrusion 42p.

[0070] In addition, various connection structures other than the above-described first metal joining portion 45 and second metal joining portion 46 may be provided in the first conductive member 41 and the second conductive member 42 .

[0071] like Fig. 9 As shown, the first conductive component 41 has a second recess 41R. The second recess 41R is formed in the approximate center of the first surface 41a of the first conductive component 41. The second recess 41R is a portion where at least a portion of the flange portion 42f is configured. In this embodiment, the large diameter portion 42fa and the small diameter portion 42fb of the flange portion 42f are configured in the second recess 41R. The second recess 41R has a shape corresponding to the large diameter portion 42fa and the small diameter portion 42fb. By having the first conductive component 41 have the second recess 41R of the flange portion 42f accommodating the second conductive component 42, the relative movement of the first conductive component 41 and the second conductive component 42 can be suppressed. As a result, it is easy to maintain the bonding of the metal bonding portions 45 and 46, and the reliability of the negative terminal 40 can be improved.

[0072] Here, when viewed along the direction in which the shaft portion 42s of the second conductive component 42 extends, the area of ​​the second recess 41R is larger than the area of ​​the first recess 41r. Therefore, the first recess 41r of the first conductive component 41 can be provided at the position of at least one of the first bottom surface 41R1 and the second bottom surface 41R2 described later. In addition, it is preferred that the second conductive component 42 has at least one of the first recess and the protrusion 42p in the region disposed in the second recess 41R. According to this structure, it is easy to maintain the bonding of the metal bonding portions 45 and 46.

[0073] In this embodiment, the second recess 41R has a first bottom surface 41R1 and a second bottom surface 41R2 having different depths. The first bottom surface 41R1 is disposed at a position deeper than the second bottom surface 41R2. Here, the first bottom surface 41R1 is disposed at the deepest position in the second recess 41R. In other words, the first bottom surface 41R1 is disposed at a position farthest from the opening 41R3 in the second recess 41R. The first bottom surface 41R1 is a substantially circular surface having a shape corresponding to the upper surface 42u1 of the small diameter portion 42fb in the flange portion 42f of the second conductive component 42. The second bottom surface 41R2 is disposed between the first bottom surface 41R1 and the opening 41R3. The second bottom surface 41R2 is a substantially annular surface having a shape corresponding to the upper surface 42u of the large diameter portion 42fa in the flange portion 42f.

[0074] The second recess 41R is recessed into a roughly circular shape with a roughly constant diameter from the opening 41R3 toward the second bottom surface 41R2. The large diameter portion 42fa has an outer diameter corresponding to the inner diameter of the side closer to the opening 41R3 than the second bottom surface 41R2 in the second recess 41R. In other words, the large diameter portion 42fa is a roughly disc-shaped portion having a diameter roughly the same as the inner diameter from the opening 41R3 of the second recess 41R to the first bottom surface 41R1. In this embodiment, the thickness of the large diameter portion 42fa is set to be slightly larger than the length from the second bottom surface 41R2 to the opening 41R3. Therefore, the large diameter portion 42fa protrudes slightly downward from the first surface 41a of the first conductive component 41. The dimensional relationship between the large diameter portion 42fa and the second recess 41R in the height direction is not limited to this dimensional relationship.

[0075] The second recessed portion 41R is recessed in a substantially truncated cone shape from the second bottom surface 41R2 to the first bottom surface 41R1. The second bottom surface 41R2 extends inward relative to the first bottom surface 41R1. Therefore, the side surface of the second recessed portion 41R is tapered in a manner that the diameter gradually decreases from the first bottom surface 41R1 toward the second bottom surface 41R2. In other words, the side surface of the second recessed portion 41R is tapered in a manner that the diameter gradually increases from the second bottom surface 41R2 toward the first bottom surface 41R1.

[0076] The first conductive member 41 and the second conductive member 42 may be mechanically fastened. In this embodiment, the second conductive member 42 is mechanically fastened to the second recess 41R of the first conductive member 41. The flange portion 42f has a fastening portion 43 mechanically fastened to the first conductive member 41.

[0077] The fastening portion 43 is implemented between the small diameter portion 42fb of the flange portion 42f and the first bottom surface 41R1 and the second bottom surface 41R2 of the first recess 41R. Here, the small diameter portion 42fb of the flange portion 42f is fitted in the first recess 41R of the first conductive component 41 and the side circumference between the first bottom surface 41R1 and the second bottom surface 41R2 protruding toward the inside. In other words, the small diameter portion 42fb of the flange portion 42f is pressed into the first recess 41R of the first conductive component 41 and is riveted to the side circumference between the second bottom surface 41R2 and the first bottom surface 41R1. By mechanically fastening the first conductive component 41 and the second conductive component 42, the first conductive component 41 and the second conductive component 42 are fastened more strongly, and the reliability of the negative terminal 40 can be improved.

[0078] For example, the form of the fastening portion 43 is not particularly limited as long as it is mechanical fastening based on dynamic energy. The fastening portion 43 may be a portion fastened by, for example, press-fitting, shrink fitting, caulking, riveting, folding, bolting, or the like.

[0079] In this embodiment, the flange portion 42f has a groove 42fc on the outer peripheral side. The groove 42fc is a portion of the flange portion 42f where the diameter is reduced, and is also called a reduced diameter portion. A portion of the first conductive component 41 is arranged in the groove 42fc. According to this structure, the first conductive component 41 and the second conductive component 42 can be more strongly fastened, so that the reliability of the negative terminal 40 can be improved. The groove 42fc is formed at the boundary between the large diameter portion 42fa and the small diameter portion 42fb. The groove 42fc can be formed continuously along the circumference of the flange portion 42f, can be formed intermittently, or can be formed locally. Preferably, the groove 42fc is continuously formed in an annular shape along the circumference of the flange portion 42f. In this embodiment, the groove 42fc is continuous in the circumferential direction, and the outer peripheral edge of the thinnest part (reduced diameter part) of the groove 42fc is circular. The length of the groove 42fc relative to the circumference is preferably 0.5 or more, more preferably 0.7 or more, and further preferably 0.9 or more. Here, the above-mentioned circumference refers to the circumference of the side circumferential surface of the flange portion 42f at a location where the groove 42fc is formed.

[0080] The fastening portion 43 is arranged at a position away from the end C1 of the contact portion C. In this embodiment, the end C1 of the contact portion C is a position where the opening 41R3 of the second recess 41R of the first conductive member 41 is formed. The end C1 is a portion exposed from the contact surface between the first conductive member 41 and the second conductive member 42. From the viewpoint of suppressing corrosion caused by an electrolyte or water, etc., it is preferred that the fastening portion 43 is arranged at a position away from the end C1 of the contact portion C. The shortest creepage distance between the fastening portion 43 and the end C1 of the contact portion C is, for example, preferably 1 mm or more, more preferably 2 mm or more, and further preferably 5 mm or more. Here, the creepage distance is a distance along the contact portion C. In this embodiment, it is a distance from the opening 41R3 of the second recess 41R of the first conductive member 41 to the base end of the small diameter portion 42fb of the second conductive member 42, and is a distance along the inner peripheral side surface of the first conductive member 41 or the outer peripheral side surface of the second conductive member 42.

[0081] Similarly, from the viewpoint of suppressing corrosion caused by electrolyte or water, etc., the second metal joint 46 is preferably arranged at a position away from the end C1 of the contact portion C. The shortest creepage distance between the second metal joint 46 and the end C1 of the contact portion C is, for example, preferably 1 mm or more, more preferably 2 mm or more, and further preferably 5 mm or more. In addition, the second metal joint 46 is preferably provided at a position closer to the inside than the fastening portion 43.

[0082] <Method for Manufacturing Negative Electrode Terminal 40>

[0083] The negative terminal 40 described above can be manufactured, for example, by a method for manufacturing a terminal for a storage device (in this embodiment, the negative terminal 40) described below. The method for manufacturing a terminal for a storage device includes a preparation step of preparing a first conductive component 41 and a second conductive component 42, a fastening step of fastening the first conductive component 41 and the second conductive component 42, and a metal bonding step of metal bonding the first conductive component 41 and the second conductive component 42. The method for manufacturing a terminal for a storage device may also include other steps.

[0084] In the preparation step, the first conductive member 41 and the second conductive member 42 are prepared. As the second conductive member 42, the second metal of the above-mentioned shape is prepared. In this embodiment, as the first conductive member 41, a metal having lower rigidity than the second conductive member 42 is used. As the first conductive member 41, a conductive member set in a shape that is deformed along the large diameter portion 42fa, the small diameter portion 42fb, and the groove 42fc of the second conductive member 42 when riveted in the fastening step is prepared.

[0085] In the fastening step, the first conductive member 41 and the second conductive member 42 are mechanically fastened. In this embodiment, the first conductive member 41 and the second conductive member 42 are mechanically fastened by caulking the first conductive member 41 with respect to the second conductive member 42.

[0086] In the fastening process, first, the first conductive component 41 is arranged in a mold (not shown). In this embodiment, the second conductive component 42 is punched relative to the first conductive component 41 in such a manner that the flange portion 42f of the second conductive component 42 is inserted into the first recess 41R of the first conductive component 41. At this time, a known punching device (not shown) or the like can be used. The first conductive component 41 is crushed because its rigidity is lower than that of the second conductive component 42, and is plastically deformed along the second conductive component 42. The edge of the first recess 41R of the first conductive component 41 is pressed into the groove 42fc of the second conductive component 42, thereby fastening the first conductive component 41 and the second conductive component 42. In the fastening process, as described above, various fastening methods for mechanically fastening the first conductive component 41 and the second conductive component 42 can be adopted.

[0087] The second conductive member 42 is provided with a protrusion 42p. In the fastening step, when the second conductive member 42 is pressed against the first conductive member 41, the protrusion 42p may be fitted into the first conductive member 41 to form the second recess 41r in the first conductive member 41.

[0088] After the first conductive member 41 and the second conductive member 42 are fastened to form the fastening portion 43 , the first conductive member 41 and the second conductive member 42 are then metal-bonded to each other.

[0089] In the metal joining process, a first metal joining portion 45 is formed at the interface between the first conductive component 41 and the second conductive component 42. In this embodiment, the first conductive component 41 and the second conductive component 42 are metal-joined by an ultrasonic joining portion. Although detailed illustrations are omitted, in the metal joining process, the first conductive component 41 and the second conductive component 42 that are fastened are clamped by a horn and an anvil, and ultrasonic vibrations are imparted to the joining interface via the horn. For example, the anvil may be inserted into the cylindrical portion of the shaft portion 42s of the second conductive component 42, the horn may be pressed against the approximate center portion of the second surface 41b of the first conductive component 41, and ultrasonic vibrations may be imparted to the first conductive component 41. As a result, the first metal joining portion 45 is formed at the approximate center portion of the interface between the first bottom surface 41R1 of the second recess 41R of the first conductive component 41 and the upper surface 42u1 of the small diameter portion 42fb of the second conductive component 42. When the bonding head is pressed against the first conductive member 41, the first conductive member 41 is pressed against the second conductive member 42. Thus, the protrusion 42p may be fitted into the first conductive member 41 to form the second recess 41r in the first conductive member 41.

[0090] In the metal bonding step, ultrasonic vibration is applied to the first conductive member 41, so that the first conductive member 41 also vibrates at the contact interface between the first recess 41r of the first conductive member 41 and the protrusion 42p of the second conductive member 42. Thus, the second metal bonding portion 46 is formed at the contact interface between the first recess 41r and the protrusion 42p. From the viewpoint of facilitating the formation of the second metal bonding portion 46, a shape that tapers toward the front end of the protrusion (a shape with a small area at the front end) is preferred.

[0091] The closer to the position where the welding head contacts, the easier it is to conduct the ultrasonic vibration imparted by the welding head. Therefore, the closer the position where the second metal joint 46 is formed is to the position where the welding head contacts (in this embodiment, the approximate center of the second surface 41b of the first conductive component 41), the easier it is to form a good second metal joint 46.

[0092] In the above-mentioned embodiment, the second conductive component 42 prepared in the preparation process is pre-provided with a protrusion 42p. However, it is not limited to this form, and the first conductive component prepared in the preparation process may also be pre-provided with a protrusion. In addition, in the preparation process, the first recess may be pre-provided in at least one of the first conductive component and the second conductive component. In the fastening process, a protrusion along the first recess of one part of the component may also be formed on the other of the first conductive component and the second conductive component. However, from the viewpoint of easily generating the second metal joint by ultrasonic vibration, it is preferred that a protrusion is pre-provided at the position where the second metal joint is formed.

[0093] The structure of the negative electrode terminal 40 is not limited to the above-mentioned embodiment. Fig.10 It is a cross-sectional view of a negative electrode terminal 40A according to another embodiment. Fig.11 It is a cross-sectional view of a negative electrode terminal 40B according to another embodiment. Fig.12 FIG. 4 is a cross-sectional view of a negative electrode terminal 40C according to another embodiment. Figures 10-12 In the figure, the same reference numerals are used for the structures common to the negative electrode terminal 40 described above, and detailed description thereof will be omitted.

[0094] exist Fig.10 In the negative terminal 40A shown in FIG. 1 , the protrusion 42p is provided at a position away from the small diameter portion 42fb. Fig. 9 ), the first recess 41r is formed at a position further away from the central axis CL than the negative terminal 40. Therefore, a structure in which the protrusion 42p and the first recess 41r are engaged is formed at a position further away from the central axis CL than the negative terminal 40. Thus, durability can be improved with respect to a load acting in a direction in which the first conductive member 41 rotates relative to the second conductive member 42.

[0095] exist Fig.11 In the negative terminal 40B shown, a recessed portion 41b1 is formed substantially in the center of the second surface 41b of the first conductive member 41. Therefore, in the metal bonding step, the distance between the position where the welding head contacts the bottom of the recessed portion 41b1 and the contact portion C becomes closer. As a result, ultrasonic vibration is easily transmitted to the interface between the first conductive member 41 and the second conductive member 42, and the bonding strength of the first metal bonding portion 45 can be improved.

[0096] The protrusion 42p of the second conductive member 42 is provided on the upper surface 42u1 of the small diameter portion 42fb. Therefore, in the metal bonding process, the distance between the position where the welding head contacts the first conductive member 41 and the protrusion 42p and the first recess 41r becomes closer. As a result, the ultrasonic vibration is easily transmitted to the interface between the protrusion 42p and the first recess 41r, and the bonding strength of the second metal bonding portion 46 can be improved.

[0097] The small diameter portion 42fb of the second conductive member 42 extends radially outward from the shaft portion 42s. Fig. 9 ), the difference between the diameters of the large diameter portion 42fa and the small diameter portion 42fb becomes smaller. As a result, the circumference of the groove 42fc becomes longer, and the length of the fastening portion 43 is also longer. As a result, the first conductive component 41 and the second conductive component 42 can be mechanically fastened more firmly.

[0098] exist Fig.12In the negative terminal 40C shown, the cross section of the protrusion 42p1 is substantially triangular in the circumferential direction of the flange 42f. The front end of the protrusion 42p1 is pointed in the cross section along the circumferential direction of the flange 42f, thereby making it easy to impart ultrasonic vibration to the interface between the first conductive member 41 and the second conductive member 42 in a state of mutual contact. As a result, the second metal joint 46 is easily formed.

[0099] Above, various descriptions have been made to the technology disclosed herein. Unless otherwise specifically mentioned, the embodiments cited herein do not limit the present invention. In addition, the technology disclosed herein can be subjected to various changes, and as long as no special problems are caused, each component and each process mentioned herein can be appropriately omitted or appropriately combined. In addition, this specification includes the disclosures recorded in the following items.

[0100] Item 1:

[0101] A terminal for an electrical storage device, comprising: a first conductive component formed of a first metal; and a second conductive component formed of a second metal different from the first metal, wherein the second conductive component comprises a flange portion and an axis portion provided on one surface of the flange portion, the second conductive component comprises a first metal joint portion on the upper surface of the flange portion that is metal-joined to the first conductive component, the second conductive component comprises at least one of a first recess and a protrusion at a position closer to the outer periphery than the first metal joint portion, the first conductive component comprises the first recess and the other of the protrusion that are engaged with at least one of the first recess and the protrusion, and the second conductive component comprises a second metal joint portion that metal-joins the first conductive component to the second conductive component at the first recess and the protrusion.

[0102] Item 2:

[0103] The terminal for a power storage device according to Item 1, wherein the first conductive member has a second recess, and at least a portion of the flange portion is disposed in the second recess.

[0104] Item 3:

[0105] The terminal for a power storage device according to Item 1 or 2, wherein the flange portion has a fastening portion mechanically fastened to the first conductive member.

[0106] Item 4:

[0107] The terminal for a power storage device according to Item 2, wherein the flange portion has a groove on an outer peripheral side surface, and a part of the first conductive member is arranged in the groove.

[0108] Item 5:

[0109] The terminal for a power storage device according to any one of items 1 to 4, comprising a contact portion where the first conductive member contacts the second conductive member, wherein the second metal joining portion is arranged at a position away from an end portion of the contact portion.

[0110] Item 6:

[0111] A power storage device, comprising: an electrode body including a positive electrode and a negative electrode; a housing accommodating the electrode body; and a terminal electrically connected to the positive electrode or the negative electrode and mounted on the housing, the terminal comprising: a first conductive member composed of a first metal; and

[0112] The second conductive member is made of a second metal different from the first metal, wherein:

[0113] The above-mentioned second conductive component has a flange portion and an axis portion arranged on one surface of the above-mentioned flange portion, the above-mentioned second conductive component has a first metal bonding portion on the upper surface of the above-mentioned flange portion that is metal-bonded with the above-mentioned first conductive component, the above-mentioned second conductive component has at least one of the first recess and the protrusion at a position closer to the outer peripheral side than the above-mentioned first metal bonding portion, the above-mentioned first conductive component has the other of the above-mentioned first recess and the above-mentioned protrusion that are embedded with at least one of the above-mentioned first recess and the above-mentioned protrusion, and the above-mentioned second conductive component has a second metal bonding portion that metal-bonds the above-mentioned first conductive component and the above-mentioned second conductive component at the above-mentioned first recess and the above-mentioned protrusion.

Claims

1. A terminal for an electric storage device, comprising: a first conductive member made of a first metal; and a second conductive member made of a second metal different from the first metal; in, The second conductive member includes a flange portion and a shaft portion provided on one surface of the flange portion. The second conductive member has a first metal bonding portion on the upper surface of the flange portion that is metal-bonded to the first conductive member. The second conductive member has at least one of a first recess and a protrusion at a position closer to the outer periphery than the first metal joint. The first conductive member includes at least one of the first recess and the projection that fits with the other of the first recess and the projection. The second conductive member includes a second metal joining portion that metal-joins the first conductive member and the second conductive member at the first recess and the protrusion.

2. The terminal for a power storage device according to claim 1, wherein The first conductive member has a second recessed portion. At least a portion of the flange portion is disposed in the second recessed portion.

3. The terminal for a power storage device according to claim 1 or 2, wherein: The flange portion includes a fastening portion that is mechanically fastened to the first conductive member.

4. The terminal for an electric storage device according to claim 2, wherein: The flange portion has a groove on the outer peripheral side surface, A portion of the first conductive member is disposed in the groove.

5. The terminal for a power storage device according to claim 1 or 2, wherein: having a contact portion where the first conductive member contacts the second conductive member, The second metal joining portion is arranged at a position away from an end portion of the contact portion.

6. An electric storage device comprising: An electrode body, including a positive electrode and a negative electrode; a housing accommodating the electrode body; and A terminal, electrically connected to the positive electrode or the negative electrode and mounted on the housing, The terminal comprises: a first conductive member made of a first metal; and a second conductive member made of a second metal different from the first metal; in, The second conductive member includes a flange portion and a shaft portion provided on one surface of the flange portion. The second conductive member has a first metal bonding portion on the upper surface of the flange portion that is metal-bonded to the first conductive member. The second conductive member has at least one of a first recess and a protrusion at a position closer to the outer periphery than the first metal joint. The first conductive member includes at least one of the first recess and the projection that fits with the other of the first recess and the projection. The second conductive member includes a second metal joining portion that metal-joins the first conductive member and the second conductive member at the first recess and the protrusion.

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