JP2024060969A - Terminal, battery equipped with same, and manufacturing method thereof - Google Patents

Abstract

[Problem] To provide a terminal with improved electrical conductivity reliability at a metal joint. [Solution] A battery terminal 40 disclosed herein comprises a first conductive member 41, a second conductive member 42 having a flange portion 42f electrically connected to the first conductive member 41, a fastening portion 43 that mechanically fastens the first conductive member 41 and the flange portion 42f of the second conductive member 42, and a metal joint portion that metal-joins the first conductive member 41 and the flange portion 42f of the second conductive member 42 at a position away from the fastening portion 43, and a gap S is provided between the first conductive member 41 and the flange portion 42f near the fastening portion 43. [Selected Figure] Figure 7

Description

The present invention relates to a terminal, a battery equipped with the same, and a manufacturing method thereof. In particular, the present invention relates to a battery terminal, a secondary battery equipped with the same, and a manufacturing method thereof.

Generally, a battery such as a lithium ion secondary battery includes an electrode body having an electrode and a battery case that houses the electrode body. In this type of battery, a terminal is known in which a terminal electrically connected to an electrode inside the battery case is drawn to the outside of the battery case. As a conventional technique related to such a terminal, for example, Patent Document 1 discloses a terminal including a first conductive member, a second conductive member having a flange portion electrically connected to the first conductive member, a fastening portion that mechanically fastens the first conductive member and the flange portion of the second conductive member, and a metal joint portion that metal-joins the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion.

JP 2022-49729 A

However, according to the inventors' research, when the first conductive member and the second conductive member are mechanically fastened together, for example, if the first conductive member deforms along the outer shape of the second conductive member, the excess material of the first conductive member has nowhere to escape, and the first conductive member may warp away from the second conductive member. As a result, it has been newly discovered that there is a risk that a gap will appear at the location where the first conductive member and the second conductive member are metal-jointed, reducing the bonding strength of the metal joint.

The present invention was made in consideration of the above circumstances, and aims to provide a terminal with improved electrical conductivity reliability at the metal joint and a method for manufacturing the same.

The present invention provides a battery terminal comprising a first conductive member, a second conductive member having a flange portion electrically connected to the first conductive member, a fastening portion that mechanically fixes the first conductive member to the flange portion of the second conductive member, and a metal joint portion that metal-joins the first conductive member to the flange portion of the second conductive member at a position away from the fastening portion, and in which a gap is provided between the first conductive member and the flange portion near the fastening portion.

In the above terminal, a gap is provided near the fastening portion. This gap confirms that there was sufficient space to allow the excess material of the deforming conductive member to escape when the fastening portion was formed. In this way, the presence of sufficient space to allow the excess material to escape when the fastening portion was formed reduces warping of the deforming conductive member and stabilizes the shape of the area where the metal joint is formed. Therefore, a metal joint in which the first conductive member and the second conductive member are in close contact can be achieved, improving the electrical reliability of the metal joint.

FIG. 1 is a perspective view showing a battery according to an embodiment of the present invention. FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. FIG. 3 is a partially enlarged cross-sectional view that typically shows the vicinity of the negative electrode terminal. FIG. 4 is a plan view illustrating a schematic diagram of a negative electrode terminal according to one embodiment. FIG. 5 is a bottom view illustrating a schematic diagram of a negative electrode terminal according to one embodiment. FIG. 6 is a side view illustrating a schematic diagram of a negative electrode terminal according to one embodiment. FIG. 7 is a schematic vertical cross-sectional view taken along line VII-VII in FIG. FIG. 8 is a partially enlarged cross-sectional view showing a schematic view of the fastening portion and its vicinity in FIG. FIG. 9 is a perspective view illustrating a battery pack according to an embodiment. FIG. 10 is an explanatory diagram illustrating the fastening portion forming step. FIG. 11 is a view corresponding to FIG. 10 according to a modified example. FIG. 12 is a schematic diagram showing a main part of a negative electrode terminal according to a modified example. FIG. 13 is a partially enlarged cross-sectional view showing a schematic example of a gap according to a modified example.

Below, preferred embodiments of the technology disclosed herein will be described with reference to the drawings. Note that matters other than those specifically mentioned in this specification that are necessary for implementing the present invention (for example, the general configuration and manufacturing process of a battery that do not characterize the present invention) can be understood as design matters for a person skilled in the art based on the prior art in the field. The present invention can be implemented based on the contents disclosed in this specification and common technical knowledge in the field.

In this specification, the term "battery" refers to any power storage device capable of extracting electrical energy, and is a concept that includes primary batteries and secondary batteries. In addition, in this specification, the term "secondary battery" refers to any power storage device capable of repeated charging and discharging, and is a concept that includes so-called storage batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, and capacitors (physical batteries) such as electric double-layer capacitors.

<Battery 100>
Fig. 1 is a perspective view of the battery 100. Fig. 2 is a schematic longitudinal sectional view taken along line II-II in Fig. 1. In the following description, the symbols L, R, U, and D in the drawings represent left, right, top, and bottom, and the symbols X, Y, and Z in the drawings represent the long side direction of the battery 100, the short side direction perpendicular to the long side direction, and the up-down direction, respectively. However, these directions are merely for the convenience of description, and do not limit the installation form of the battery 100 in any way.

As shown in FIG. 2, the battery 100 includes an electrode body 10, a battery case 20, a positive electrode terminal 30, and a negative electrode terminal 40. The battery 100 is characterized by including the positive electrode terminal 30 and/or the negative electrode terminal 40 disclosed herein, and other configurations may be similar to those of a conventional battery. The battery 100 here is a lithium ion secondary battery. Although not shown, the battery 100 here further includes an electrolyte. The battery 100 is configured by housing the electrode body 10 and an electrolyte (not shown) in the battery case 20.

The electrode body 10 may be the same as in the past, and is not particularly limited. The electrode body 10 has 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 via a strip-shaped separator, and wound around a winding axis. However, the electrode body 10 may also be a laminated electrode body in which a square-shaped (typically rectangular) positive electrode and a square-shaped (typically rectangular) negative electrode are stacked in an insulated state.

The positive electrode has a positive electrode current collector 11 and a positive electrode mixture layer (not shown) fixed on the positive electrode current collector 11. The positive electrode current collector 11 is made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The positive electrode mixture layer contains a positive electrode active material (e.g., lithium transition metal complex oxide). The negative electrode has a negative electrode current collector 12 and a negative electrode mixture layer (not shown) fixed on the negative electrode current collector 12. The negative electrode current collector is made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel. The negative electrode mixture layer contains a negative electrode active material (e.g., a carbon material such as graphite).

As shown in FIG. 2, a laminated portion is formed in the central portion (shaded portion) of the long side direction X of the electrode body 10, in which the positive electrode mixture layer and the negative electrode mixture layer are laminated in an insulated state. On the other hand, at the left end of the long side direction X of the electrode body 10, a part of the positive electrode current collector 11 on which the positive electrode mixture layer is not formed (positive electrode current collector exposed portion) protrudes from the laminated portion. A positive electrode lead member 13 is attached to the positive electrode current collector exposed portion. The positive electrode lead member 13 may be made of the same metal material as the positive electrode current collector 11, for example, a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. In addition, at the right end of the long side direction X of the electrode body 10, a part of the negative electrode current collector 12 on which the negative electrode mixture layer is not formed (negative electrode current collector exposed portion) protrudes from the laminated portion. A negative electrode lead member 14 is attached to the negative electrode current collector exposed portion. The material (metal type) of the negative electrode lead member 14 may be different from that of the positive electrode lead member 13. The negative electrode lead member 14 may be made of the same metal type as the negative electrode current collector 12, such as a conductive metal such as copper, a copper alloy, nickel, or stainless steel.

The electrolyte may be the same as that used in the past, and is not particularly limited. The electrolyte is, for example, a non-aqueous liquid electrolyte (non-aqueous electrolyte solution) containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent contains, 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 may be a solid (solid electrolyte) and integrated with the electrode body 10.

The battery case 20 is a housing that houses the electrode body 10. Here, the battery case 20 is formed in a flat, bottomed rectangular parallelepiped (rectangular) shape. However, the shape of the battery case 20 is not limited to a rectangular shape, and may be any shape such as a cylinder. The material of the battery case 20 may be the same as that used conventionally, and is not particularly limited. The battery case 20 is made of a lightweight metal material with good thermal conductivity, such as aluminum, aluminum alloy, or stainless steel. As shown in FIG. 2, the battery case 20 includes a case body 22 having an opening 22h, and a lid body (sealing plate) 24 that closes the opening 22h. The battery case 20 is integrated by joining (for example, welding) the lid body 24 to the periphery of the opening 22h of the case body 22. The battery case 20 is hermetically sealed (sealed).

The case body 22 has a flat bottom surface 22d. The lid body 24 faces the bottom surface 22d of the case body 22. The lid body 24 is substantially rectangular here. In this specification, the term "substantially rectangular" includes not only a perfect rectangular shape (rectangular shape), but also shapes in which the corners connecting the long and short sides of the rectangle are rounded, or shapes in which the corners have notches, etc.

As shown in FIG. 1, the positive electrode terminal 30 and the negative electrode terminal 40 protrude to the outside of the battery case 20. Here, the positive electrode terminal 30 and the negative electrode terminal 40 each protrude from the same surface of the battery case 20 (specifically, the lid body 24). However, the positive electrode terminal 30 and the negative electrode terminal 40 may each protrude from different surfaces of the battery case 20. The positive electrode terminal 30 and the negative electrode terminal 40 are fixed to the battery case 20 (specifically, the lid body 24). The positive electrode terminal 30 and the negative electrode terminal 40 are disposed at both ends of the long side direction X of the lid body 24. The positive electrode terminal 30 and/or the negative electrode terminal 40 are an example of the battery terminal disclosed herein. In particular, it is preferable that the negative electrode terminal 40 is the battery terminal disclosed herein.

The positive electrode terminal 30 is electrically connected to the positive electrode of the electrode body 10 via the positive electrode lead member 13 inside the battery case 20. The negative electrode terminal 40 is electrically connected to the negative electrode of the electrode body 10 via the negative electrode lead member 14 inside the battery case 20. The positive electrode terminal 30 and the negative electrode terminal 40 are each attached to the lid body 24. The positive electrode terminal 30 and the negative electrode terminal 40 are each insulated from the lid body 24 via a gasket 50 (see FIG. 3) and an insulator 60 (see FIG. 3), which will be described later.

Figure 3 is a partially enlarged cross-sectional view showing the vicinity of the negative electrode terminal 40. Note that the terminal structure on the negative electrode terminal 40 side will be described in detail below as an example, but the terminal structure on the positive electrode terminal 30 side may be similar. In that case, in the following description, the word "negative electrode" can be read as "positive electrode" as appropriate.

As shown in FIG. 3, the cover 24 is formed with a terminal pull-out hole 24h that penetrates in the vertical direction Z. In a plan view, the terminal pull-out hole 24h is, for example, annular (e.g., circular). The terminal pull-out hole 24h has an inner diameter large enough to insert the shaft column portion 42s of the negative terminal 40 before crimping, which will be described later. The terminal pull-out hole 24h is formed smaller than the flange portion 42f of the negative terminal 40, which will be described later.

The negative electrode lead member 14 is attached to the exposed portion of the negative electrode current collector 12 and constitutes a conductive path that electrically connects the negative electrode and the negative electrode terminal 40. The negative electrode lead member 14 has a flat portion 14f that spreads horizontally along the inner surface of the lid 24. The flat portion 14f has a through hole 14h formed at a position corresponding to the terminal pull-out hole 24h. The through hole 14h has an inner diameter large enough to insert the shaft column portion 42s of the negative electrode terminal 40 before crimping, which will be described later. The negative electrode lead member 14 is fixed to the lid 24 by crimping in a state insulated via the insulator 60.

The gasket 50 is an insulating member disposed between the upper surface (outer surface) of the lid 24 and the negative electrode terminal 40. Here, the gasket 50 has the function of insulating the lid 24 from the negative electrode terminal 40 and closing the terminal extraction hole 24h. The gasket 50 is made of an electrically insulating and elastically deformable resin material, for example, a fluorinated resin such as perfluoroalkoxy fluorine resin (PFA), polyphenylene sulfide resin (PPS), aliphatic polyamide, etc.

As shown in FIG. 3, the gasket 50 has a tubular portion 51 and a base portion 52. The tubular portion 51 is a portion that prevents direct contact between the cover body 24 and the shaft column portion 42s of the negative terminal 40. The tubular portion 51 has a hollow cylindrical shape. The tubular portion 51 has a through hole 51h that penetrates in the vertical direction Z. The through hole 51h is formed so that the shaft column portion 42s of the negative terminal 40 before the crimping process can be inserted. The tubular portion 51 is inserted into the terminal extraction hole 24h of the cover body 24. The base portion 52 is a portion that prevents direct contact between the cover body 24 and the flange portion 42f of the negative terminal 40 described later. The base portion 52 is connected to the upper end of the tubular portion 51. The base portion 52 extends horizontally from the upper end of the tubular portion 51. The base portion 52 is formed, for example, in a ring shape so as to surround the terminal extraction hole 24h of the cover body 24. The base 52 extends along the upper surface of the lid 24. The base 52 is sandwiched between the lower surface 42d of the flange portion 42f of the negative terminal 40 and the upper surface of the lid 24, and is compressed in the vertical direction Z by crimping.

The insulator 60 is an insulating member disposed between the lower surface (inner surface) of the lid 24 and the negative electrode lead member 14. The insulator 60 has a function of insulating the lid 24 and the negative electrode lead member 14. The insulator 60 has a flat portion that spreads horizontally along the inner surface of the lid 24. A through hole 60h is formed in this flat portion at a position corresponding to the terminal pull-out hole 24h. The through hole 60h has an inner diameter large enough to insert the shaft column portion 42s of the negative electrode terminal 40. The insulator 60 has resistance to the electrolyte used and electrical insulation properties, and is made of a resin material that can be elastically deformed, such as a fluorinated resin such as perfluoroalkoxy fluorine resin (PFA) or polyphenylene sulfide resin (PPS). The flat portion of the insulator 60 is sandwiched between the lower surface of the lid 24 and the upper surface of the negative electrode lead member 14, and is compressed in the vertical direction Z by crimping.

<Negative electrode terminal 40>
The negative terminal 40 extends from the inside to the outside of the battery case 20 through the terminal pull-out hole 24h. As described below, the negative terminal 40 is configured by integrating two types of conductive members, i.e., a first conductive member 41 and a second conductive member 42, with a fastening portion 43 and a metal joint portion 45. As shown in FIG. 3, the negative terminal 40 is crimped to the peripheral portion surrounding the terminal pull-out hole 24h of the lid body 24 while being insulated from the lid body 24. A rivet portion 40c is formed at the lower end of the negative terminal 40. The negative terminal 40 is fixed to the lid body 24 by crimping and is electrically connected to the negative lead member 14.

Figures 4 to 6 are schematic diagrams of the negative electrode terminal 40 before it is attached to the lid 24 (i.e., before crimping), with Figure 4 being a plan view (top view), Figure 5 being a bottom view, and Figure 6 being a side view. Also, Figure 7 is a schematic vertical cross-sectional view taken along line VII-VII in Figure 4, which shows a schematic vertical cross-sectional view of the main parts of the negative electrode terminal 40. As shown in Figure 7, the negative electrode terminal 40 includes a first conductive member 41, a second conductive member 42, a fastening portion 43, and a metal joint portion 45. The first conductive member 41 and the second conductive member 42 are integrated and electrically connected to each other via two types of connecting portions that are connected by different methods, namely, the fastening portion 43 and the metal joint portion 45.

The first conductive member 41 is a member disposed outside the battery case 20. Here, the first conductive member 41 is made of metal. The first conductive member 41 is made of a conductive metal such as aluminum, an aluminum alloy, nickel, stainless steel, or copper. The first conductive member 41 preferably has a Brinell hardness (HB) of 40 or more. Here, the first conductive member 41 is made of aluminum. The aluminum temper is preferably A1050-H18/H24, A3003-H18/H24, or the like. The first conductive member 41 may have a temper changed by adding a minute element for the purpose of improving workability, etc. The first conductive member 41 may be the same metal as the positive electrode lead member 13, or an alloy having the same metal element as the first component (the component with the highest mixing ratio by mass; the same applies below).

As shown in Figs. 4 to 6, the first conductive member 41 is plate-shaped. The first conductive member 41 is preferably plate-shaped. Here, the first conductive member 41 is flat. The first conductive member 41 has a lower surface 41d and an upper surface 41u. The lower surface 41d is the surface facing the battery case 20 (specifically, the lid body 24). The upper surface 41u is the surface away from the battery case 20. Here, the first conductive member 41 is substantially rectangular. The first conductive member 41 is a portion divided into two in the long side direction X, and has a connection portion 41a electrically connected to the second conductive member 42, and an extension portion 41b extending from the connection portion 41a to one side in the long side direction X (to the left in Figs. 4 to 6).

As shown in FIG. 7, the connection portion 41a has a thin-walled portion 41t (see also FIG. 4) that is thinner than the extension portion 41b, a through hole 41h that penetrates in the vertical direction Z, and a recess 41r that is recessed from the lower surface 41d of the first conductive member 41. A metal joint portion 45 is provided in the thin-walled portion 41t. As shown in FIG. 4, the thin-walled portion 41t is formed in an annular shape (e.g., a circular ring shape) in a plan view. It is preferable that the first conductive member 41 has the thin-walled portion 41t. It is preferable that the thin-walled portion 41t is provided so as to surround the periphery of the through hole 41h.

The through hole 41h is formed in a ring shape (for example, a circular ring shape) in a plan view. The second conductive member 42 (specifically, the flange portion 42f) is exposed from the through hole 41h on the upper surface 41u of the first conductive member 41. As shown in FIG. 7, the through hole 41h is provided in the center of the thin-walled portion 41t. It is preferable that the through hole 41h is provided in the center of the thin-walled portion 41t. The through hole 41h is provided on the inner periphery side of the fastening portion 43 and the metal joint portion 45. The through hole 41h can function as an escape route for gas and heat generated during welding. It is preferable that the first conductive member 41 has the through hole 41h in a region facing the second conductive member 42 (particularly, in the vicinity of the metal joint portion 45).

The recess 41r is provided on the outer periphery side of the metal joint 45. Although not shown, the recess 41r is formed in an annular shape (for example, a circular ring) in a plan view. The recess 41r is formed in a tapered shape that decreases in diameter toward the lower surface 41d of the first conductive member 41 (in other words, as it approaches the second conductive member 42). A constricted portion 42n of the second conductive member 42 described later is inserted into the recess 41r. The first conductive member 41 has a recess 41r on the lower surface 41d, and it is preferable that a part of the second conductive member 42 described later (for example, the constricted portion 42n) is disposed in the recess 41r. As will be described in detail later, the counterbore diameter of the recess 41r before being fastened to the second conductive member 42 is larger than the outer shape of the constricted portion 42n. As a result, a gap S is formed between the side of the recess 41r and the constricted portion 42n of the second conductive member 42.

The recess 41r has a bottom wall 41m. The bottom wall 41m extends toward the thin portion 41t. The bottom wall 41m (the lower surface of the thin portion 41t) faces the second conductive member 42 (more specifically, the upper surface 42u of the flange portion 42f described below). The bottom wall 41m of the recess 41r is a flat surface (straight line in cross section) that is not warped. The bottom wall 41m of the recess 41r is in close contact with the second conductive member 42. The bottom wall 41m of the recess 41r is an example of an upper surface facing region that faces the upper surface 42u of the second conductive member 42.

The extension portion 41b is a portion to which a bus bar 90 (see FIG. 9), which is a conductive member, is attached when, for example, a plurality of batteries 100 are electrically connected to each other to produce a battery pack 200 (see FIG. 9). By having the extension portion 41b, a sufficient ground contact area with the bus bar 90 can be secured, and the electrical reliability of the battery pack 200 can be improved. As shown in FIGS. 4 and 5, the first conductive member 41 has the extension portion 41b, and therefore its center position 41c is shifted to the right in the long side direction X from the center position 42c of the second conductive member 42 (more specifically, the center position of the flange portion 42f described later).

The second conductive member 42 is a member extending from the inside to the outside of the battery case 20. Here, the second conductive member 42 is made of metal. The second conductive member 42 is made of a conductive metal such as copper, copper alloy, nickel, or stainless steel. The material of the second conductive member 42 may be, for example, the first component of the second conductive member 42 may be the same as that of the first conductive member 41, or may be different. Here, the second conductive member 42 is made of a metal having a higher hardness than the first conductive member 41. Here, the second conductive member 42 is made of copper. The copper temper is preferably C1020, C1100, or the like. The second conductive member 42 may be tempered by adding a minute element for the purpose of improving workability, etc. The second conductive member 42 may be made of the same metal as the negative electrode lead member 14, or an alloy having the same metal element as the first component. The second conductive member 42 may have a metal coating portion coated with a metal such as Ni on a part or all of its surface. This increases resistance to electrolytes and improves corrosion resistance.

The second conductive member 42 is preferably columnar. As shown in Figs. 6 and 7, the second conductive member 42 has an axis C. The second conductive member 42 has a flange portion 42f electrically connected to the first conductive member 41, and an axial column portion 42s connected to the lower end of the flange portion 42f.

The flange portion 42f has a larger outer shape than the shaft column portion 42s. As shown in FIG. 3, the flange portion 42f has a larger outer shape than the terminal pull-out hole 24h of the lid body 24. The flange portion 42f is a portion that protrudes from the terminal pull-out hole 24h of the lid body 24 to the outside of the battery case 20. As shown in FIGS. 5 to 7, the outer shape of the flange portion 42f is approximately cylindrical. As shown in FIGS. 6 and 7, the axis of the flange portion 42f coincides with the axis C of the second conductive member 42. As shown in FIG. 7, the flange portion 42f has a lower surface 42d, a side surface (outer peripheral surface) 42o extending upward from the lower surface 42d, a constricted portion 42n in which a portion of the side surface 42o is constricted, and an upper surface 42u extending upward from the constricted portion 42n.

The constricted portion 42n is provided continuously or intermittently on a part of the side surface 42o of the flange portion 42f. The constricted portion 42n is preferably formed on the side surface 42o near the end of the upper surface 42u side (for example, within 10 mm from the upper surface 42u). Although not shown, the constricted portion 42n is formed in a ring shape (for example, annular) in a plan view. When the constricted portion 42n is formed in a ring shape, a high-strength fastening portion 43 can be formed. The constricted portion 42n is formed axially symmetrically with respect to the axis C of the flange portion 42f. The constricted portion 42n is formed in an inverted tapered shape that expands toward the upper surface 41u (in other words, the further away from the shaft column portion 42s). The constricted portion 42n is inserted into the recess 41r of the first conductive member 41. Here, the constricted portion 42n is inserted into the recess 41r of the first conductive member 41 and fits into the recess 41r. As will be described in detail later, there is a gap S between the side of the constricted portion 42n and the recess 41r of the first conductive member 41.

The upper surface 42u faces the bottom wall 41m (the lower surface of the thin portion 41t) of the recess 41r of the first conductive member 41. Here, the upper surface 42u is a flat surface (linear in cross-sectional view). However, it may be a curved surface (curved in cross-sectional view).

As shown in FIG. 7, the shaft column portion 42s extends downward from the lower end of the flange portion 42f. As shown in FIGS. 5 to 7, the shaft column portion 42s is cylindrical here. The axis of the shaft column portion 42s coincides with the axis C of the flange portion 42f. Before the crimping process, the lower end of the shaft column portion 42s, i.e., the end opposite to the side where the flange portion 42f is located, is hollow. As shown in FIG. 3, the shaft column portion 42s is a portion that is inserted into the terminal extraction hole 24h of the lid body 24 when the negative terminal 40 is attached to the lid body 24. The lower end of the shaft column portion 42s is a portion that is expanded by the crimping process when the negative terminal 40 is attached to the lid body 24 and forms the rivet portion 40c. The shaft column portion 42s is electrically connected to the negative electrode lead member 14 inside the battery case 20 by the crimping process.

The fastening portion 43 is a connecting portion that mechanically fixes the first conductive member 41 and the flange portion 42f of the second conductive member 42. The fastening portion 43 is provided on the outer periphery side of the flange portion 42f from the metal joint portion 45 in a plan view. The fastening portion 43 is formed in a ring shape (for example, annular) in a plan view. This increases the strength of the fastening portion 43, and further improves the conduction reliability of the negative terminal 40. The fastening portion 43 is formed continuously here. Although not particularly limited, the fastening portion 43 is provided on the lower surface 41d of the first conductive member 41 here. Specifically, the side wall of the recess 41r of the first conductive member 41 is fixed (for example, pressed and fixed) to the side surface of the constriction portion 42n of the second conductive member 42. This improves the strength of the fastening portion 43.

The method of forming the fastening portion 43 is not particularly limited as long as it is a mechanical joint using mechanical energy, and may be, for example, press-fitting, shrink fitting, crimping, riveting, folding, bolting, etc. In some preferred embodiments, the fastening portion 43 is a fitting portion in which the recess 41r of the first conductive member 41 and the constricted portion 42n of the second conductive member 42 are fitted together. This allows the first conductive member 41 and the second conductive member 42 to be suitably fixed together, for example, even if the first conductive member 41 and the second conductive member 42 are made of different metals. The fastening portion 43 may be, for example, a press-fit fitting portion in which the constricted portion 42n of the second conductive member 42 is fitted into the recess 41r of the first conductive member 41 by press-fitting.

Figure 8 is a partially enlarged cross-sectional view showing the vicinity of the fastening portion 43 in Figure 7. As shown in Figure 8, in this embodiment, a gap S is provided between the first conductive member 41 and the flange portion 42f of the second conductive member 42 near the fastening portion 43. The gap S confirms that there was sufficient space to serve as an escape route for the excess material of the conductive member that deforms (here, the first conductive member 41) when the fastening portion 43 is formed.

That is, according to the study by the inventors, when the fastening portion 43 is formed, if there is not enough space near the fastening portion 43 formation position, when the first conductive member 41 is deformed along the outer shape of the second conductive member 42, there is no escape route for the excess material of the first conductive member 41 that is crushed along the constriction portion 42n. Therefore, the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41 may be warped away from the upper surface 42u of the flange portion 42f of the second conductive member 42. As a result, a gap may be formed at the location where the first conductive member 41 and the second conductive member 42 are metal-joined, here between the upper surface 42u of the flange portion 42f of the second conductive member 42 and the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41.

In contrast, in this embodiment, there is sufficient space for excess material to escape when the first conductive member 41 deforms, so warping of the first conductive member 41 is reduced and the shape of the bottom wall 41m (upper surface facing region) of the recess 41r is stable. Therefore, the upper surface 42u of the flange portion 42f of the second conductive member 42 and the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41 are suitably in close contact with each other.

As shown in FIG. 8, the gap S is preferably provided in the end area EA. As shown by the dashed line in FIG. 8, the end area EA is within a length range of 25% (i.e., within _L1 /4) of the distance _L1 from the outer peripheral edge 42e of the upper surface 42u of the flange portion 42f when the distance (shortest distance) from the end of the metal joint portion 45 to the outer peripheral edge 42e of the upper surface 42u is _L1 . Since the end area EA is a place where the load is small when fastening, a space that serves as a stable escape route for excess metal can be secured, and the gap S can be maintained. Although not particularly limited, the distance _L1 is 2.2 mm here. Therefore, the end area EA is within a length range of 0.55 mm (=2.2/4) from the outer peripheral edge 42e of the upper surface 42u. The end region EA can be a region in contact with the upper surface 42u of the flange portion 42f and/or a region in contact with the side surface 42o of the flange portion 42f (for example, the narrowed portion 42n).

In the fastening portion 43, the constricted portion 42n of the second conductive member 42 has a first region A1 and a second region A2 in the region where it abuts against the recess 41r of the first conductive member 41. The first region A1 is inclined, for example, at an angle of 60 to 110° with respect to the axis C of the second conductive member 42. The first region A1 is preferably inclined at an angle of 70 to 100° with respect to the axis C of the second conductive member 42, and more preferably at an angle of 80 to 95°. Here, the first region A1 is a flat surface (linear in cross-sectional view). However, it may also be a curved surface (curved in cross-sectional view).

The second region A2 is located closer to the upper surface 42u of the flange portion 42f than the first region A1. The second region A2 is inclined at an angle of, for example, 15 to 70° with respect to the axis C of the second conductive member 42. The second region A2 is inclined at an angle of generally less than 90° with respect to the axis C of the second conductive member 42, preferably at an angle of 20 to 70°, more preferably at an angle of 45 to 70°, and even more preferably at an angle of 60 to 70°. It is preferable that the angle of inclination of the second region A2 is smaller than that of the first region A1. Here, the second region A2 is a flat surface (linear in cross section). However, it may be a curved surface (curved in cross section).

The constricted portion 42n of the second conductive member 42 preferably includes a third region A3 that connects the first region A1 and the second region A2. The third region A3 is preferably formed in a concave shape having a curved surface in a cross-sectional view. The third region A3 abuts the recess 41r of the first conductive member 41. The constricted portion 42n of the second conductive member 42 preferably includes a fourth region A4 that is disposed approximately parallel (within ±10°) to the axis C of the second conductive member 42 on the side closer to the upper surface 42u than the second region A2. Here, the fourth region A4 connects the second region A2 and the upper surface 42u. This allows the gap S to be preferably secured in the end region EA, for example, at the position in contact with the fourth region A4.

The gap S can be secured, for example, by previously processing the portion where the fastening portion 43 of the flange portion 42f of the first conductive member 41 and/or the second conductive member 42 is to be formed. Here, the gap S is secured by previously making the countersunk diameter of the recess 41r of the first conductive member 41 before it is fastened to the second conductive member 42 larger than the outer shape of the constriction portion 42n.

The size and shape of the gap S are not particularly limited as long as the effect of the technology disclosed herein is exhibited. In a cross-sectional view of an arbitrary cross section passing through the axis C of the second conductive member 42 and along the axis C, the cross-sectional area of the gap S is preferably 0.002 mm ² or more, more preferably 0.005 mm ² or more, and even more preferably 0.008 mm ² or more. The cross-sectional area of the gap S is preferably 0.06 mm ² or less, more preferably 0.03 mm ² or less, and even more preferably 0.01 mm ² or less. The height of the gap S (maximum length in the vertical direction Z) is preferably 0.03 mm or more, more preferably 0.05 mm or more, and even more preferably 0.08 mm or more. The height of the gap S is preferably 0.50 mm or less, more preferably 0.30 mm or less, and even more preferably 0.10 mm or less. The width of the gap S (maximum length in the long side direction X) is preferably 0.03 mm or more, more preferably 0.05 mm or more, and even more preferably 0.08 mm or more. The width of the gap S is preferably 0.50 mm or less, more preferably 0.30 mm or less, and even more preferably 0.10 mm or less. In FIG. 8, the width of the gap S is 0.25 mm (0 to 12% of the distance _L1 ).

Here, the voids S are provided in a ring shape (for example, a circular ring shape) in a plan view along the outer peripheral edge 42e of the upper surface 42u. The total volume of the voids S is preferably ^0.05 mm3 or more, more preferably 0.1 ^mm3 or more, and even more preferably 0.3 mm3 ^or more. The total volume of the voids S is preferably ³ mm3 or less, more preferably ^1.5 mm3 or less, and even more preferably ^0.5 mm3 or less. By setting the size or total volume of the voids S to a predetermined value or more, the voids S can be stably secured. By setting the size or total volume of the voids S to a predetermined value or less, the strength of the fastening portion 43 can be improved.

The metal joint 45 is a metallurgical joint between the first conductive member 41 and the flange portion 42f of the second conductive member 42. The metal joint 45 is provided at a position away from the fastening portion 43. Here, the metal joint 45 is provided on the upper surface 41u of the first conductive member 41. Specifically, the metal joint 45 is formed by metal-joining the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41 and the upper end surface (upper surface 42u of the flange portion 42f) of the second conductive member 42. The metal joint 45 is provided at a position away from the through hole 41h. The metal joint 45 is provided on the outer periphery side of the through hole 41h. The metal joint 45 can be a joint with a relatively high rigidity compared to, for example, the fastening portion 43.

Here, the metal joint 45 is provided on the radially inner side (center side) of the flange portion 42f relative to the fastening portion 43 in a plan view. The metal joint 45 is formed using light energy, electron energy, thermal energy, etc., and therefore may be a joint with relatively low strength (fragile) compared to the fastening portion 43. By disposing such a metal joint 45 on the inner side of the fastening portion 43, the metal joint 45 can be stably maintained and the electrical reliability of the negative electrode terminal 40 can be improved over a long period of time. Here, the metal joint 45 is provided on the thin-walled portion 41t. It is preferable that the metal joint 45 is formed on the thin-walled portion 41t. This requires less energy during joining and improves weldability.

The metal joint 45 is formed continuously or intermittently. The metal joint 45 is formed axially symmetrically with respect to the axis C of the flange portion 42f. The metal joint 45 is formed in an annular shape (e.g., annular) in a plan view. This increases the strength of the metal joint 45, and further improves the electrical reliability of the negative electrode terminal 40.

The method of forming the metal joint 45 is not particularly limited, and may be, for example, fusion welding, pressure welding, brazing, etc. In some preferred embodiments, the metal joint 45 is a welded joint formed by welding, for example, laser welding, electron beam welding, ultrasonic welding, resistance welding, TIG (Tungsten Inert Gas) welding, etc. This allows a high-strength metal joint 45 to be stably formed. However, the metal joint 45 may also be formed by a method other than welding, for example, thermocompression bonding, ultrasonic pressure welding, brazing, etc.

<Method of manufacturing negative electrode terminal 40>
Although not particularly limited, the negative electrode terminal 40 can be manufactured by, for example, preparing the first conductive member 41 and the second conductive member 42 as described above, and by a manufacturing method including a fastening portion forming step and a metal joint forming step. The metal joint forming step is preferably performed after the fastening portion forming step. However, the order of the fastening portion forming step and the metal joint forming step may be reversed, or may be substantially simultaneous. In addition, the manufacturing method disclosed herein may further include other steps at any stage. FIG. 10 is an explanatory diagram for explaining the fastening portion forming step.

In the fastening portion forming process, the first conductive member 41 and the flange portion 42f of the second conductive member 42 are mechanically fixed to form the fastening portion 43. The fastening portion 43 can be formed, for example, by inserting the constricted portion 42n of the second conductive member 42 into the recess 41r of the first conductive member 41, and deforming the recess 41r of the first conductive member 41 along the outer shape of the constricted portion 42n of the second conductive member 42, thereby fixing the inner wall of the recess 41r with the second conductive member 42. This can improve the strength of the fastening portion 43. In this embodiment, the fastening portion 43 is formed by fitting the recess 41r of the first conductive member 41 and the constricted portion 42n of the second conductive member 42 together. For example, the fastening portion 43 is formed by horizontally pressing the constricted portion 42n of the second conductive member 42 into the recess 41r of the first conductive member 41. This can improve the workability of the fastening portion forming process.

Specifically, as shown in FIG. 10(1), the first conductive member 41 has an annular side wall 41s extending downward from the bottom wall (upper surface facing region) of the recess 41r before being fastened to the second conductive member 42. The countersink diameter of the side wall 41s is larger than the outer shape of the fourth region A4 of the constriction 42n by the width Δd. Such a first conductive member 41 is abutted against the upper surface 42u of the flange portion 42f of the second conductive member 42, and pressure is applied to the first conductive member 41 in a direction that coincides with the axis C of the second conductive member 42, as shown by the arrow in FIG. 10(2). As a result, the side wall 41s of the first conductive member 41 is pressed against the first region A1 of the second conductive member 42. Then, as shown by the arrow in FIG. 10(3), a part of the side wall 41s (annular inner region) moves upward along the constriction 42n. As a result, the first region A1 and the second region A2 of the second conductive member 42 come into contact with the side wall portion 41s of the first conductive member 41. Then, the side wall portion 41s of the first conductive member 41 deforms so as to enter the constricted portion 42n of the second conductive member 42.

At this time, in the method disclosed herein, the material of the side wall portion 41s of the first conductive member 41 is not completely filled in the vicinity of the portion where the fastening portion 43 is formed, specifically, on the side of the fourth region A4 of the second conductive member 42, and a gap S is secured. In other words, a gap S is formed between the first conductive member 41 and the flange portion 42f of the second conductive member 42. The gap S indicates that there was a sufficient space to serve as an escape route for the excess material of the first conductive member 41 that has moved upward. In other words, the fact that the gap S is secured indicates that the excess material of the first conductive member 41 has nowhere to go and the first conductive member 41 does not warp. Therefore, according to the method disclosed herein, the shape of the bottom wall 41m (upper surface facing region) of the recess 41r is stabilized, and the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41 and the upper surface 42u of the flange portion 42f of the second conductive member 42 can be suitably brought into close contact with each other. In this manner, the first conductive member 41 and the flange portion 42f of the second conductive member 42 are connected to form the fastening portion 43.

In the metal joint forming process, the thin-walled portion 41t of the first conductive member 41 and the flange portion 42f of the second conductive member 42 are metal-joined, i.e., metallurgically joined, to form the metal joint 45. By performing the metal joint forming process after the fastening portion forming process, the metal joint 45 having a stable shape can be formed with high precision. The metal joint 45 can be formed, for example, by metal-joining the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41 and the upper surface 42u of the flange portion 42f of the second conductive member 42. More specifically, the metal joint 45 can be formed by welding the thin-walled portion 41t of the first conductive member 41 and the flange portion 42f of the second conductive member 42, where they are stacked, so as to penetrate the thin-walled portion 41t. Gas and heat generated during welding are released and diffused through the through hole 41h. The through hole 41h can prevent gas and heat from accumulating between the thin-walled portion 41t and the flange portion 42f. Welding allows for the stable formation of a high-strength metal joint 45.

In some preferred embodiments, the metal joint 45 is formed on the inner side of the fastening portion 43. This makes the joint less likely to shift, improving the workability of the metal joint formation process. Also, when the metal joint 45 is formed by welding, the welded portion is less likely to wobble, improving weldability. Furthermore, when welding the thin-walled portion 41t, less energy is required, improving weldability.

<Manufacturing method of battery 100>
The battery 100 is characterized by using the positive electrode terminal 30 and/or the negative electrode terminal 40 manufactured by the manufacturing method as described above. The rest of the manufacturing process may be the same as in the conventional method. The battery 100 can be manufactured by, for example, preparing the electrode body 10, the electrolyte, the case body 22, the lid body 24, the positive electrode terminal 30, and the negative electrode terminal 40 as described above, and by a manufacturing method including an attachment step and a joining step.

In the mounting process, the positive terminal 30, the positive lead member 13, the negative terminal 40, and the negative lead member 14 are attached to the lid body 24. The negative terminal 40 and the negative lead member 14 are fixed to the lid body 24 by crimping (riveting), for example, as shown in FIG. 3. The crimping process is performed by sandwiching a gasket 50 between the negative terminal 40 and the lid body 24, and further sandwiching an insulator 60 between the lid body 24 and the negative lead member 14. In detail, the shaft column portion 42s of the negative terminal 40 before crimping is penetrated from above the lid body 24 through the cylindrical portion 51 of the gasket 50, the terminal extraction hole 24h of the lid body 24, the through hole 60h of the insulator 60, and the through hole 14h of the negative lead member 14 in that order, and protrudes downward from the lid body 24. Then, the shaft column 42s protruding downward from the lid 24 is crimped so that a compressive force is applied in the vertical direction Z. This forms a rivet portion 40c at the tip end (lower end in FIG. 3) of the shaft column 42s of the negative terminal 40.

By such crimping, the base 52 of the gasket 50 and the flat portion of the insulator 60 are compressed, and the gasket 50, the lid 24, the insulator 60, and the negative electrode lead member 14 are fixed integrally to the lid 24, and the terminal extraction hole 24h is sealed. The method of attaching the positive electrode terminal 30 and the positive electrode lead member 13 may be the same as that of the negative electrode terminal 40 and the negative electrode lead member 14 described above. The negative electrode lead member 14 is welded to the negative electrode collector exposed portion of the negative electrode collector 12, and the negative electrode of the electrode body 10 and the negative electrode terminal 40 are electrically connected. Similarly, the positive electrode lead member 13 is welded to the positive electrode collector exposed portion of the positive electrode collector 11, and the positive electrode of the electrode body 10 and the positive electrode terminal 30 are electrically connected. As a result, the lid 24, the positive electrode terminal 30, the negative electrode terminal 40, and the electrode body 10 are integrated.

In the joining process, the electrode body 10 integrated with the lid 24 is housed in the internal space of the case body 22, and the case body 22 and the lid 24 are sealed. The sealing can be performed by welding, for example, laser welding. Thereafter, a nonaqueous electrolyte is injected through a filling port (not shown), and the filling port is closed to hermetically seal the battery 100. In this manner, the battery 100 can be manufactured.

<Uses of battery 100>
Although the battery 100 can be used for various purposes, it can be suitably used in applications requiring high bonding strength, for example, as a power source (driving power source) for a motor mounted on a vehicle such as a passenger car, a truck, etc. The type of vehicle is not particularly limited, but examples thereof include a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), and a battery electric vehicle (BEV).

As shown in FIG. 9, the battery 100 can also be suitably used as a battery pack 200 in which a plurality of batteries 100 are electrically connected to each other via a bus bar 90. In this case, the electrical connection between the plurality of batteries 100 can be achieved by, for example, bridging a flat bus bar 90 between the extensions 41b of the first conductive member 41. The bus bar 90 is made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The bus bar 90 and the extensions 41b can be electrically connected by welding, for example, laser welding.

Although several embodiments of the present invention have been described above, the above embodiments are merely examples. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in the relevant field. The technology described in the claims includes various modifications and changes to the above-exemplified embodiments. For example, it is possible to replace part of the above-mentioned embodiments with other modified forms, and it is also possible to add other modified forms to the above-mentioned embodiments. Furthermore, if a technical feature is not described as essential, it can also be deleted as appropriate.

(1) For example, in the above embodiment, the first conductive member 41 and the second conductive member 42 are made of different metals. Specifically, the first conductive member 41 is made of aluminum, and the second conductive member 42 is made of copper. However, this is not limited to this. The first conductive member 41 and the second conductive member 42 may be made of the same type of metal. For example, the first conductive member 41 and the second conductive member 42 may both be made of aluminum, and the first conductive member 41 and the second conductive member 42 may both be made of copper.

(2) For example, in the above embodiment, the gap S was secured by making the countersink diameter of the first conductive member 41 larger than the outer shape of the constricted portion 42n of the second conductive member 42. However, this is not limited to this. The gap S can also be secured by forming a recess (including a step, a groove, a notch, etc., the same applies below) in a part of the bottom wall 41m (upper surface facing region) of the recess 41r of the first conductive member 41. Since the bottom wall 41m (upper surface facing region) of the recess 41r is a place where the load is small when fastening, a gap S of stable volume can be secured by providing a recess on the upper surface 42u. The gap S can also be secured by forming a recess in the part of the first conductive member 41 that faces the fourth region A4 of the constricted portion 42n. Furthermore, the gap S can also be secured by forming a recess in a part of the upper surface 42u of the flange portion 42f of the second conductive member 42.

Figure 11 is a view corresponding to Figure 10 for a modified example. As shown in Figure 11 (1), the second conductive member 142 has an annular step portion 142s on the upper surface 142u of the flange portion 142f before being fastened to the first conductive member 141. The step portion 142s is provided near the outer periphery of the upper surface 142u (end area EA, not shown). The step portion 142s is recessed from the upper surface 142u. The step portion 142s is an example of a recessed portion.

Such a second conductive member 42 is brought into contact with the bottom surface 141m (upper surface facing region) of the recess 141r of the first conductive member 141, and pressure is applied in the same manner as in the above embodiment, as shown by the arrow in FIG. 11 (2). As a result, the material of the first conductive member 141 is deformed so as to enter the constricted portion 42n of the second conductive member 42. In this modified example, as shown in FIG. 11 (3), the material of the first conductive member 41 is not completely filled in the step portion 142s, and a gap S1 is secured near the outer periphery of the upper surface 142u. Since the load on the upper surface 142u is small when fastened, a gap S1 of stable volume can be secured by providing the step portion 142s on the upper surface 142u. The size or total volume of the gap S1 may be within the range of the above embodiment.

(3) In the above embodiment, the constricted portion 42n of the second conductive member 42 is inserted into the recess 41r of the first conductive member 41. However, this is not limited to this. The fastening portion 43 may be configured as in the following modified example, for example.

Figure 12 is a schematic diagram showing a main part of a negative terminal 240 according to a modified example. The negative terminal 240 includes a first conductive member 241, a second conductive member 242 having a flange portion 242f, a fastening portion 243, and a metal joint portion 245. The first conductive member 241 has a portion having an approximately T-shaped outer shape. The first conductive member 241 has a columnar portion 241c inserted into the recess 242r. The columnar portion 241c has an axis C. The flange portion 242f of the second conductive member 242 has a circular recess 242r. The recess 242r is formed in a tapered shape that decreases in diameter as it approaches the first conductive member 241. The recess 242r may be a through hole that penetrates in the vertical direction Z. The second conductive member 242 may have a groove or a notch at the connection between the recess 242r and the upper surface 242u (the circled area in FIG. 12).

The fastening portion 243 can be formed, for example, by inserting the columnar portion 241c of the first conductive member 241 into the recess 242r of the second conductive member 242 and applying pressure in a direction that coincides with the axis C of the columnar portion 241c. The pressure may be applied to the columnar portion 241c of the first conductive member 241 or to the recess 242r of the second conductive member 242. If the recess 242r is a through hole, pressure may be applied so as to sandwich the columnar portion 241c from above and below. At this time, in the vicinity of the fastening portion 243, specifically, in the connection portion between the recess 242r and the upper surface 242u (the circled area in FIG. 12), the material of the columnar portion 241c is not completely filled, and a gap is secured.

Figure 13 is an enlarged view of the circled portion of Figure 12, and is a partially enlarged cross-sectional view showing a schematic example of a gap according to a modified example. In Figure 13 (A), gap S2 is secured by providing a groove at the connection between recess 242r and upper surface 242u of second conductive member 242. In Figure 13 (B), gap S3 is secured by providing a notch at the connection between recess 242r and upper surface 242u of second conductive member 242. The size or total volume of gaps S2 and S3 may be within the range of the above-mentioned embodiment.

(4) For example, in the above embodiment, the first conductive member 41 has a thin portion 41t, and the metal joint 45 is formed in the thin portion 41t. The metal joint 45 is provided at a position away from the through hole 41h. However, this is not limited to this. The metal joint 45 may be formed, for example, in a portion other than the thin portion 41t, or may be formed along the outer edge of the through hole 41h.

(5) For example, in the above embodiment, the negative electrode lead member 14 and the negative electrode terminal 40 are electrically connected by deforming and crimping the shaft column portion 42s of the negative electrode terminal 40. However, this is not limited to this. The method of electrically connecting the negative electrode lead member 14 and the negative electrode terminal 40 may be, for example, a mechanical fixation other than crimping, a metal joint such as welding, or a combination of these. From the viewpoint of increasing the reliability of the connection, a fastening portion that mechanically fixes the negative electrode lead member 14 and the negative electrode terminal 40 and a metal joint that continuously or intermittently metal-joints the periphery of the fastening portion may be formed at the connection portion between the negative electrode lead member 14 and the negative electrode terminal 40.

As described above, specific aspects of the technology disclosed herein include those described in the following sections.
Item 1: A battery terminal comprising: a first conductive member; a second conductive member having a flange portion electrically connected to the first conductive member; a fastening portion that mechanically fixes the first conductive member and the flange portion of the second conductive member; and a metal joining portion that metal-joints the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion, wherein a gap is provided between the first conductive member and the flange portion in the vicinity of the fastening portion.
Item 2: The battery terminal according to item 1, wherein the flange portion of the second conductive member has a constricted portion on a side surface, the fastening portion is configured by mechanically fixing the first conductive member and the constricted portion of the flange portion, the flange portion of the second conductive member has an upper surface, the first conductive member has an upper surface facing region that faces the upper surface of the flange portion, and the metal joint portion is configured by metal joining the upper surface and the upper surface facing region.
Item 3: The battery terminal according to item ₂ , wherein the gap is provided in an end region on the upper surface of the flange portion, the end region being defined as a region having a length within 25% of the distance _L1 from the outer periphery of the upper surface, where L1 is a distance from the metal joint portion to the outer periphery of the upper surface.
Item 4: The battery terminal according to item 2 or 3, wherein a recess is provided in the vicinity of the outer periphery of the upper surface of the flange portion.
Item 5: The battery terminal according to item 2 or 3, wherein the first conductive member has a recess in a portion facing the outer circumferential edge of the upper surface of the flange portion.
Item 6: A secondary battery comprising the battery terminal according to any one of items 1 to 5.
Item 7: A method for manufacturing a terminal for a battery comprising: a first conductive member; a second conductive member having a flange portion electrically connected to the first conductive member; a fastening portion that mechanically fixes the first conductive member and the flange portion of the second conductive member; and a metal joint portion that metal-joins the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion, the method comprising: a fastening portion forming process for mechanically fixing the first conductive member and the flange portion of the second conductive member by deforming the first conductive member to form the fastening portion; and a metal joint forming process for metal-joining the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion, wherein in the fastening portion forming process, a gap is secured between the first conductive member and the flange portion in the vicinity of the fastening portion.
Item 8: A manufacturing method as described in Item 7, wherein the flange portion of the second conductive member has a constricted portion on a side surface, the fastening portion forming process mechanically fixes the first conductive member and the constricted portion of the second conductive member, the flange portion of the second conductive member has an upper surface, the first conductive member has an upper surface facing region that faces the upper surface of the flange portion, and the metal joint forming process metal-joints the upper surface and the upper surface facing region.
Item 9: The manufacturing method according to item 8, wherein in the fastening portion forming step, when a distance from the metal joint portion to an outer peripheral edge of the upper surface of the flange portion is _L1 , the gap is secured in an end region that is defined as a region having a length within 25% of the distance _L1 from the outer peripheral edge.
Item 10: The manufacturing method according to item 8 or 9, wherein a recess is provided in the vicinity of the outer periphery of the upper surface of the flange portion.
Item 11: The manufacturing method according to item 8 or 9, wherein the first conductive member has a recess in a portion facing the outer circumferential edge of the upper surface of the flange portion.
Item 12: A method for producing a secondary battery using a battery terminal produced by the method according to any one of items 7 to 11.

REFERENCE SIGNS LIST 10 Electrode body 14 Negative electrode lead member 20 Battery case 24 Lid body 24h Terminal pull-out hole 30 Positive electrode terminal 40, 240 Negative electrode terminal 41, 141, 241 First conductive member 42, 142, 242 Second conductive member 43, 143, 243 Fastening portion 45, 245 Metal joint portion 100 Battery

Claims (12)

A first conductive member;
a second conductive member having a flange portion electrically connected to the first conductive member;
a fastening portion that mechanically fastens the first conductive member and the flange portion of the second conductive member;
a metal joint portion that metal-joins the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion;
Equipped with
a gap is provided between the first conductive member and the flange portion near the fastening portion. the flange portion of the second conductive member has a constricted portion on a side surface,
the fastening portion is configured by mechanically fixing the first conductive member and the narrowed portion of the flange portion,
the flange portion of the second conductive member has an upper surface,
the first conductive member has an upper surface facing region facing the upper surface of the flange portion,
The metal joint portion is configured by metal-jointing the upper surface and the upper surface facing region.
The battery terminal according to claim 1 . In the upper surface of the flange portion, when a distance from the metal joint portion to an outer peripheral edge of the upper surface is defined as _L1 , the gap is provided in an end region defined as a region having a length within 25% of the distance _L1 from the outer peripheral edge.
The battery terminal according to claim 2 . A recess is provided in the vicinity of the outer circumferential edge of the upper surface of the flange portion.
The battery terminal according to claim 2 or 3. The first conductive member has a recess in a portion facing an outer circumferential edge of the upper surface of the flange portion.
The battery terminal according to claim 2 or 3. The battery terminal according to claim 1 or 2 is provided.
Secondary battery. 1. A method for manufacturing a battery terminal comprising: a first conductive member; a second conductive member having a flange portion electrically connected to the first conductive member; a fastening portion that mechanically fixes the first conductive member and the flange portion of the second conductive member; and a metal joining portion that metal-joins the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion,
a fastening portion forming process of mechanically fixing the first conductive member and the flange portion of the second conductive member by deforming the first conductive member to form the fastening portion;
a metal joint forming process of metal-jointing the first conductive member and the flange portion of the second conductive member at a position away from the fastening portion to form a metal joint;
having
In the fastening portion forming step, a gap is provided between the first conductive member and the flange portion in the vicinity of the fastening portion.
A method for manufacturing battery terminals. the flange portion of the second conductive member has a constricted portion on a side surface,
the fastening portion forming step mechanically fastens the first conductive member and the constricted portion of the second conductive member;
the flange portion of the second conductive member has an upper surface, and the first conductive member has an upper surface facing region facing the upper surface of the flange portion,
In the metal bond forming step, the upper surface and the upper surface facing region are metal-bonded to each other.
The method of claim 7. In the fastening portion forming step, when a distance from the metal joint portion to an outer peripheral edge of the upper surface of the flange portion is defined as _L1 , the gap is secured in an end region defined as a region having a length within 25% of the distance _L1 from the outer peripheral edge.
The method according to claim 8. A recess is provided in the vicinity of the outer circumferential edge of the upper surface of the flange portion.
The method according to claim 8 or 9. The first conductive member has a recess in a portion facing an outer circumferential edge of the upper surface of the flange portion.
The method according to claim 8 or 9. A battery terminal manufactured by the manufacturing method according to claim 8 or 9 is used.
A method for manufacturing a secondary battery.

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