Terminal and battery having the same

Abstract

To provide a terminal that is constituted by welding and joining dissimilar metals which prevents a liquid from entering from the surface of a welded joint part.SOLUTION: A terminal includes a first conductive member 70, a second conductive member 80 which is electrically connected to the first conductive member 70, and a welded joint part 64 for welding and joining the first conductive member 70 and the second conductive member 80. The first conductive member 70 and the second conductive member 80 are composed of different kinds of metals, and the welded joint part 64 is formed so as to penetrate through the first conductive member 70 and reach the second conductive member 80. Here, a surface 64a of the welded joint part 64 is covered with a tape 90 and / or a resin member.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a terminal and a battery including the same. [Background technology]

[0002] In recent years, terminals (electrode terminals, i.e., positive and negative terminals) have been proposed that are constructed by joining dissimilar metals together in order to achieve good bonding between terminals and external members such as bus bars. Patent Document 1 discloses a terminal that is made of a first conductive member and a second conductive member that are dissimilar metals, and the terminal has a metal bonding portion that metal-bonds the first conductive member and the second conductive member together in order to improve the reliability of electrical conduction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-49729 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of intensive research by the present inventors, it was found that the above technology has room for improvement in terms of corrosion resistance and electrical conductivity reliability. In detail, when dissimilar metals are welded, cracks may occur at the welded joint due to embrittlement of the welded joint or differences in the expansion coefficients between the dissimilar metals. The cracks allow conductive liquids such as water, salt water, and electrolytes to seep in from the surface of the welded joint and penetrate into the interface between the dissimilar metals. When dissimilar metals are brought into contact with conductive liquids, the cationization of metals with low potential is promoted. That is, there is a risk that metals with high ionization tendency and metals with low potential will corrode rapidly. Therefore, in a terminal formed by welding dissimilar metals, it is an issue to prevent liquids from entering from the surface of the welded joint.

[0005] The object of the technology disclosed herein has been made in consideration of the above circumstances, and is to provide a terminal that is constructed by welding dissimilar metals together, and that prevents liquid from entering through the surface of the welded joint. [Means for solving the problem]

[0006] The terminal disclosed herein includes a first conductive member, a second conductive member electrically connected to the first conductive member, and a welded joint that welds the first conductive member and the second conductive member together. The first conductive member and the second conductive member are made of different metals, and the welded joint is formed to penetrate the first conductive member and reach the second conductive member. Here, the surface of the welded joint is covered with a tape and / or a resin member.

[0007] According to this configuration, a terminal is provided that suppresses the intrusion of liquid from the surface of the welded joint. More specifically, the terminal has a welded joint formed to penetrate the first conductive member and reach the second conductive member. The terminal has the welded joint in this configuration, thereby improving the electrical conductivity reliability of the terminal. The surface of the welded joint is covered with tape and / or a resin member. This prevents liquid from intruding from the surface of the welded joint. This suppresses liquid from coming into contact with the first conductive member and the second conductive member, causing corrosion of the first conductive member or the second conductive member. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a battery according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. [Diagram 3] 1 is a vertical cross-sectional view that illustrates a schematic view of a main portion of a negative electrode terminal according to a first embodiment. [Figure 4] FIG. 2 is a plan view illustrating a schematic view of a main part of the negative electrode terminal according to the first embodiment. [Diagram 5]FIG. 6 is a vertical cross-sectional view that illustrates a schematic view of a main portion of a negative electrode terminal according to a second embodiment. [Figure 6] FIG. 11 is a plan view illustrating a schematic view of a main portion of a negative electrode terminal according to a second embodiment. [Figure 7] FIG. 1 is a perspective view showing a schematic diagram of a battery pack according to an embodiment; [Figure 8] FIG. 11 is a vertical cross-sectional view that illustrates a schematic view of a main portion of a negative electrode terminal according to a third embodiment. [Figure 9] FIG. 11 is a vertical cross-sectional view that illustrates a schematic view of a main portion of a negative electrode terminal according to a fourth embodiment. [Figure 10] FIG. 11 is a plan view illustrating a schematic view of a main part of a negative electrode terminal according to a fourth embodiment. [Figure 11] FIG. 13 is a vertical cross-sectional view that illustrates a schematic view of a main portion of a negative electrode terminal according to a fifth embodiment. [Figure 12] FIG. 13 is a plan view illustrating a schematic view of a main part of a negative electrode terminal according to a fifth embodiment. [Figure 13] FIG. 13 is a vertical cross-sectional view that illustrates a schematic view of a main part of a negative electrode terminal according to a sixth embodiment. [Figure 14] FIG. 13 is a plan view illustrating a schematic view of a main part of a negative electrode terminal according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the technology disclosed herein will be described with reference to the drawings. Matters not mentioned in this specification and necessary for implementing the technology disclosed herein can be understood as design matters for a person skilled in the art based on the prior art in the field. The technology disclosed herein can be implemented based on the contents disclosed in this specification and the technical common sense in the field. In addition, in the following drawings, members and parts that perform the same function are described with the same reference numerals. Furthermore, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. In addition, the numerical range expressed as "A to B" in this specification includes A and B, and also includes the meaning of "preferably larger than A" and "preferably smaller than B".

[0010] 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.

[0011] <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, short side direction perpendicular to the long side direction, and up-down direction of the battery 100, 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.

[0012] As shown in FIG. 2, the battery 100 includes an electrode body 1, a battery case 20, a positive electrode terminal 50, and a negative electrode terminal 60. The battery 100 is characterized by including the positive electrode terminal 50 and / or the negative electrode terminal 60 disclosed herein, and other configurations may be similar to those of conventional batteries. 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 1 and an electrolyte (not shown) in the battery case 20.

[0013] The electrode body 1 may be the same as a conventional one, and is not particularly limited. The electrode body 1 has a positive electrode and a negative electrode (not shown). The electrode body 1 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 1 may 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 foil 2 and a positive electrode mixture layer (not shown) fixed on the positive electrode current collector foil 2. The positive electrode current collector foil 2 is made of a conductive metal such as aluminum, aluminum alloy, nickel, stainless steel, etc. The positive electrode mixture layer contains a positive electrode active material (for example, lithium transition metal complex oxide). The negative electrode has a negative electrode current collector foil 4 and a negative electrode mixture layer (not shown) fixed on the negative electrode current collector foil 4. The negative electrode current collector foil 4 is made of a conductive metal such as copper, a copper alloy, nickel, stainless steel, etc. The negative electrode mixture layer contains a negative electrode active material (for example, a carbon material such as graphite).

[0014] As shown in FIG. 2, a laminated portion is formed in the center of the long side direction X of the electrode body 1, in which the positive electrode mixture layer and the negative electrode mixture layer are laminated in an insulated state. Meanwhile, at the left end of the long side direction X of the electrode body 1, a part of the positive electrode current collector foil 2 on which the positive electrode mixture layer is not formed (positive electrode current collector foil exposed part) protrudes from the laminated portion. A positive electrode current collector 8 is attached to the positive electrode current collector foil exposed part. The positive electrode current collector 8 may be made of the same metal material as the positive electrode current collector foil 2, 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 1, a part of the negative electrode current collector foil 4 on which the negative electrode mixture layer is not formed (negative electrode current collector foil exposed part) protrudes from the laminated portion. A negative electrode current collector 10 is attached to the negative electrode current collector foil exposed part. The material (metal type) of the negative electrode current collector 10 may be different from that of the positive electrode current collector 8. The negative electrode current collector 10 may be made of the same metal as the negative electrode current collector foil 4, for example, a conductive metal such as copper, a copper alloy, nickel, or stainless steel. A current interrupter (CID) may be provided between the positive electrode terminal 50 and the positive electrode current collector 8 or between the negative electrode terminal 60 and the negative electrode current collector 10.

[0015] 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 may be integrated with the electrode body 1.

[0016] The battery case 20 is a housing that houses the electrode body 1. 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 24, and a sealing plate (lid) 30 that closes the opening 24. The sealing plate 30 is provided with a thin-walled safety valve (not shown) that is set to release the internal pressure when the internal pressure of the battery case 20 rises to a predetermined level or higher, and an injection port (not shown) for injecting a non-aqueous electrolyte. The battery case 20 is integrated by joining (for example, welding) the sealing plate 30 to the periphery of the opening 24 of the case body 22. The battery case 20 is hermetically sealed (sealed).

[0017] The case body 22 has a flat bottom surface 22d. The sealing plate 30 faces the bottom surface 22d of the case body 22. The sealing plate 30 is attached to the case body 22 so as to close the opening 24 of the case body 22. The sealing plate 30 here has a substantially rectangular shape. In this specification, the term "substantially rectangular shape" includes not only a perfect rectangular shape (rectangular shape) but also a shape in which the corners connecting the long and short sides of the rectangle are rounded or a shape in which the corners have notches.

[0018] As shown in FIG. 1, the positive electrode terminal 50 and the negative electrode terminal 60 protrude to the outside of the battery case 20. Here, the positive electrode terminal 50 and the negative electrode terminal 60 each protrude from the same surface of the battery case 20 (specifically, the sealing plate 30). However, the positive electrode terminal 50 and the negative electrode terminal 60 may each protrude from different surfaces of the battery case 20. The positive electrode terminal 50 and the negative electrode terminal 60 are disposed at both end portions of the sealing plate 30 in the long side direction X. The positive electrode terminal 50 and / or the negative electrode terminal 60 are an example of the terminal disclosed herein.

[0019] Fig. 3 is a vertical cross-sectional view showing a schematic view of a main part of the negative electrode terminal 60 according to the first embodiment. Fig. 4 is a plan view showing a schematic view of a main part of the negative electrode terminal 60 according to the first embodiment. Note that, although the terminal structure on the negative electrode terminal 60 side will be described in detail below as an example, the terminal structure on the positive electrode terminal 50 side may be similar. In that case, in the following description, the word "negative electrode" can be appropriately read as "positive electrode".

[0020] 3, the sealing plate 30 is formed with a terminal mounting hole 32 penetrating in the up-down direction Z. In a plan view, the terminal mounting hole 32 is, for example, annular (for example, circular). The terminal mounting hole 32 has an inner diameter large enough to allow a connection portion 88 of the negative electrode terminal 60, which will be described later, to be inserted therethrough before crimping. The terminal mounting hole 32 is formed smaller than a flange portion 81 of the negative electrode terminal 60, which will be described later.

[0021] The negative electrode current collector 10 is attached to the exposed portion of the negative electrode current collector foil 4, and constitutes a conductive path that electrically connects the negative electrode and the negative electrode terminal 60. The negative electrode current collector 10 has a flat portion 12 that spreads horizontally along the inner surface of the sealing plate 30. The flat portion 12 has a through hole 14 formed at a position corresponding to the terminal mounting hole 32. The through hole 14 has an inner diameter large enough to insert a connection portion 88 of the negative electrode terminal 60 before crimping, which will be described later. The negative electrode current collector 10 is fixed to the sealing plate 30 by crimping in an insulated state via the insulator 46.

[0022] The gasket 40 is an insulating member disposed between the upper surface (outer surface) of the sealing plate 30 and the negative electrode terminal 60. Here, the gasket 40 has a function of insulating the sealing plate 30 from the negative electrode terminal 60 and closing the terminal mounting hole 32. The gasket 40 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, or the like.

[0023] The gasket 40 has a tubular portion 41 and a base portion 43. The tubular portion 41 is a portion that prevents direct contact between the sealing plate 30 and the connection portion 88 of the negative electrode terminal 60. The tubular portion 41 has a hollow cylindrical shape. The tubular portion 41 has a through hole 42 that penetrates in the vertical direction Z. The through hole 42 is formed so that the connection portion 88 of the negative electrode terminal 60 before the crimping process can be inserted therethrough. The tubular portion 41 is inserted into the terminal mounting hole 32 of the sealing plate 30. The base portion 43 is a portion that prevents direct contact between the sealing plate 30 and the flange portion 81 of the negative electrode terminal 60 described later. The base portion 43 is connected to the upper end of the tubular portion 41. The base portion 43 extends horizontally from the upper end of the tubular portion 41. The base portion 43 is formed, for example, in a circular ring shape so as to surround the terminal mounting hole 32 of the sealing plate 30. The base 43 extends along the upper surface of the sealing plate 30. The base 43 is sandwiched between the lower surface 81d of the flange portion 81 of the negative electrode terminal 60 and the upper surface of the sealing plate 30, and is compressed in the vertical direction Z by crimping.

[0024] The insulator 46 is an insulating member disposed between the lower surface (inner surface) of the sealing plate 30 and the negative electrode current collector 10. The insulator 46 has a function of insulating the sealing plate 30 and the negative electrode current collector 10. The insulator 46 has a flat plate-shaped portion that spreads horizontally along the inner surface of the sealing plate 30. A through hole 48 is formed in this flat plate-shaped portion at a position corresponding to the terminal mounting hole 32. The through hole 48 has an inner diameter large enough to insert the connection part 88 of the negative electrode terminal 60. The insulator 46 is made of a resin material that has resistance to the electrolyte used and electrical insulation properties, and is elastically deformable, for example, a fluorinated resin such as perfluoroalkoxy fluorine resin (PFA) or polyphenylene sulfide resin (PPS). The flat plate-shaped portion of the insulator 46 is sandwiched between the lower surface of the sealing plate 30 and the upper surface of the negative electrode current collector 10, and is compressed in the vertical direction Z by crimping.

[0025] <Negative terminal 60> The negative electrode terminal 60 extends from the inside to the outside of the battery case 20 through the terminal mounting hole 32. As described later, the negative electrode terminal 60 is configured by integrating two different types of conductive members, a first conductive member 70 and a second conductive member 80, made of metals, with a welded joint 64. As shown in FIG. 3, the negative electrode terminal 60 is crimped to the peripheral portion surrounding the terminal mounting hole 32 of the sealing plate 30 while being insulated from the sealing plate 30. A rivet portion 66 is formed at the lower end of the negative electrode terminal 60. The negative electrode terminal 60 is fixed to the sealing plate 30 and electrically connected to the negative electrode current collector 10 by crimping.

[0026] As shown in FIG. 3, the negative electrode terminal 60 according to the technology disclosed herein has a first conductive member 70, a second conductive member 80, and a welded joint 64, and further has a tape 90 and / or a resin member 96 (see FIG. 5).

[0027] 3, in some preferred embodiments, the negative terminal 60 includes a fastening portion 62. The first conductive member 70 and the second conductive member 80 are integrated and electrically connected to each other via the fastening portion 62 and a welded joint 64.

[0028] The first conductive member 70 is a member disposed outside the battery case 20. The first conductive member 70 is made of metal here. The first conductive member 70 is, for example, a conductive metal such as aluminum, an aluminum alloy, nickel, stainless steel, copper, or a copper alloy, and is preferably aluminum or an aluminum alloy. As shown in FIG. 3 and FIG. 4, the first conductive member 70 is plate-shaped here. Although not particularly limited, the first conductive member 70 has a substantially rectangular shape extending in the long side direction X here. The first conductive member 70 has a lower surface 70d and an upper surface 70u. The lower surface 70d is a surface facing the battery case 20 (specifically, the sealing plate 30). The upper surface 70u is a surface away from the battery case 20. In the technology disclosed herein, the lower surface is an example of the "one surface" and the upper surface is an example of the "other surface".

[0029] The first conductive member 70 has a recess 77 recessed from a lower surface 70d of the first conductive member 70. The recess 77 is provided on the outer periphery side of the welded joint 64. Although not shown, the recess 77 is formed in an annular (e.g., circular) shape in a plan view. Here, the recess 77 is formed in a tapered shape that reduces in diameter toward the lower surface 70d of the first conductive member 70 (in other words, as it approaches the second conductive member 80). A narrowed portion 84 of the second conductive member 80, which will be described later, is inserted into the recess 77.

[0030] The first conductive member 70 has a through hole 72 penetrating in the up-down direction Z. The through hole 72 is formed in an annular shape (for example, annular) in a plan view. As shown in FIG. 3, the through hole 72 has a first region (small diameter portion) 73 and a second region (large diameter portion) 74. The first region 73 is a region having a smaller diameter than the second region 74. The first region 73 is disposed at a position closer to the second conductive member 80 than the second region 74. A horizontal region 75 extending horizontally from the upper end of the first region 73 is formed between the first region 73 and the second region 74. The second conductive member 80 (specifically, a flange portion 81 described later) is disposed so as to close the through hole 72. According to this configuration, when the first conductive member 70 and the second conductive member 80 are fixed by welding, it can act as a gas escape flow path during welding. The through hole 72 may also function as an air vent hole when the negative electrode terminal 60 is fixed to the sealing plate 30 by riveting. The second conductive member 80 (specifically, a flange portion 81 described later) is exposed from the through hole 72 on the upper surface 70u of the first conductive member 70.

[0031] The second conductive member 80 is a member extending from the inside to the outside of the battery case 20. Here, the second conductive member 80 is made of metal. The second conductive member 80 is, for example, a conductive metal such as copper, a copper alloy, nickel, stainless steel, aluminum, or an aluminum alloy, and is preferably copper or a copper alloy. The second conductive member 80 may have a metal coating portion in which a metal different from that of the first conductive member 70 is coated on a part or all of the surface. This improves the welding quality with the first conductive member. The metal coating portion of the second conductive member 80 is preferably provided on the surface where the first conductive member 70 and the second conductive member 80 abut against each other. As shown in FIG. 3, the second conductive member 80 has an axis C. Here, the second conductive member 80 has a flange portion 81 electrically connected to the first conductive member 70 at one end, and a connection portion (shaft column portion) 88 connected to the lower end of the flange portion 81 at the other end.

[0032] In the terminal disclosed herein, the first conductive member 70 and the second conductive member 80 are made of different metals. In some preferred embodiments, the first conductive member 70 is made of aluminum or an aluminum alloy, and the second conductive member 80 is made of copper or a copper alloy. Alternatively, there may be an embodiment in which the first conductive member 70 is made of copper or a copper alloy, and the second conductive member 80 is made of aluminum or an aluminum alloy. A terminal having such a configuration is used, for example, in a fast-charging battery or the like.

[0033] The flange portion 81 has an outer shape larger than the connection portion 88. As shown in FIG. 3, the flange portion 81 has an outer shape larger than the terminal attachment hole 32 of the sealing plate 30. The flange portion 81 is a portion that protrudes from the terminal attachment hole 32 of the sealing plate 30 to the outside of the battery case 20. Although not shown in the drawings, the outer shape of the flange portion 81 here is substantially cylindrical, and the axis of the flange portion 81 coincides with the axis C of the second conductive member 80. As shown in FIG. 3, the flange portion 81 has a lower surface 81d, a side surface (outer peripheral surface) 82 extending upward from the lower surface 81d, and a constricted portion 84 in which a portion of the side surface 82 is constricted.

[0034] The constricted portion 84 is provided continuously or intermittently on a part of the side surface 82 of the flange portion 81. Although not shown, the constricted portion 84 is formed in an annular shape (for example, a circular ring) in a plan view. When the constricted portion 84 is formed in an annular shape, a high-strength fastening portion 62 can be formed. The constricted portion 84 is formed symmetrically with respect to the axis C of the flange portion 81. The constricted portion 84 is formed in an inverted tapered shape that expands in diameter toward the upper surface 70u (in other words, the further away from the connection portion 88). The constricted portion 84 is inserted into the recess 77 of the first conductive member 70. Here, the constricted portion 84 is fitted into the recess 77 of the first conductive member 70 and is fitted into the recess 77. The constricted portion 84 is an example of a "portion accommodated in the recess 77" in the technology disclosed herein.

[0035] As shown in FIG. 3, the connection portion 88 extends downward from the lower end of the flange portion 81. Here, the connection portion 88 has a cylindrical shape. The axis of the connection portion 88 coincides with the axis C of the flange portion 81. Before the crimping process, the lower end of the connection portion 88, i.e., the end opposite to the side where the flange portion 81 is located, is hollow. As shown in FIG. 3, the connection portion 88 is a portion that is inserted into the terminal attachment hole 32 of the sealing plate 30 when the negative electrode terminal 60 is attached to the sealing plate 30. The lower end of the connection portion 88 is a portion that is pushed open by the crimping process and forms the rivet portion 66 when the negative electrode terminal 60 is attached to the sealing plate 30. The connection portion 88 is electrically connected to the negative electrode current collector 10 inside the battery case 20 by the crimping process.

[0036] The fastening portion 62 is a connecting portion that mechanically fixes the first conductive member 70 and the flange portion 81 of the second conductive member 80. The fastening portion 62 is preferably provided on the outer periphery side of the flange portion 81 relative to the welded joint portion 64 in a plan view. The fastening portion 62 is formed in an annular (for example, annular) shape in a plan view. This increases the strength of the fastening portion 62, and further improves the conduction reliability of the negative electrode terminal 60. The fastening portion 62 is configured by fixing (for example, pressing and fixing) the inner wall of the recess 77 of the first conductive member 70 to the constricted portion 84 of the second conductive member 80. This allows the first conductive member 70 and the second conductive member 80 to be suitably fixed, and the strength of the fastening portion 62 to be improved. The method of forming the fastening portion 62 is not particularly limited as long as it is a mechanical joint using mechanical energy, and may be, for example, press fitting, shrink fitting, caulking, riveting, folding, bolt joining, or the like.

[0037] The welded joint 64 is a metallurgical joint between the first conductive member 70 and the flange portion 81 of the second conductive member 80. In this specification, the term "welded joint" refers to a portion where the metal constituting the conductive member melts and solidifies during welding. The welded joint 64 is provided on the upper surface 70u of the first conductive member 70. As shown in FIG. 3, the welded joint 64 is preferably formed so as to penetrate the first conductive member 70 in the vertical direction Z from the upper surface 70u of the first conductive member 70 and reach the second conductive member 80. This increases the strength of the welded joint 64, and further improves the conduction reliability of the negative electrode terminal 60. The welded joint 64 is preferably provided at a position away from the fastening portion 62. In addition, the welded joint 64 is preferably provided on the inner periphery side (center side) of the flange portion 81 relative to the fastening portion 62 in a plan view. The welded joint 64 is formed using light energy, electron energy, heat energy, etc., and therefore may be a joint having a relatively low strength (fragile) compared to the fastening portion 62. By disposing such a welded joint 64 on the inner circumferential side of the fastening portion 62, the welded joint 64 can be stably maintained and the conduction reliability of the negative electrode terminal 60 can be improved over a long period of time. The welded joint 64 is provided in the horizontal region 75 here. This requires less energy during joining and improves weldability. The welded joint 64 is formed continuously or intermittently. The welded joint 64 is formed symmetrically with respect to the axis C of the flange portion 81. This increases the strength of the welded joint 64 and further improves the conduction reliability of the negative electrode terminal 60. The welded joint 64 is formed, for example, in a ring shape (for example, a circular ring), a circular arc shape, preferably a circle having two or more layers (for example, a multiple circle such as a double circle or a triple circle), or a spiral shape in a plan view. In other words, the welded joint 64 is formed by dividing it into small welded joints. As shown in Figs. 3 and 4, the welded joint 64 is formed in a double circle shape. As a result, the welded joint 64 is formed by dividing it into small welded joints, so that the occurrence of cracks is suppressed. Therefore, the strength of the welded joint 64 can be increased, and the electrical conductivity reliability of the negative electrode terminal 60 can be further improved.

[0038] The welded joint 64 is formed by, for example, laser welding, electron beam welding, resistance welding, TIG (Tungsten Inert Gas) welding, etc. This makes it possible to stably form the high-strength welded joint 64.

[0039] In this way, by including the fastening portion 62 and the welded joint portion 64, the negative electrode terminal 60 can stably maintain the conductive connection between the first conductive member 70 and the second conductive member 80, thereby improving the conductive reliability of the negative electrode terminal 60. However, the fastening portion 62 is not essential and can be omitted in other embodiments.

[0040] As described above, the welded joint 64 is formed by melting and solidifying the first conductive member 70 and the second conductive member 80, which are different kinds of metals, during welding. However, when different kinds of metals are welded, cracks may occur in the welded joint 64 due to embrittlement of the alloy part, differences in the expansion coefficients between the different metals, local non-uniform concentrations of solute elements, and the like. When such cracks occur, there is a room for water and the like to penetrate through the surface 64a of the welded joint 64 (specifically, the surface of the welded joint 64 that is formed on the upper surface 70u of the first conductive member 70). Therefore, in the technology disclosed herein, the surface 64a of the welded joint 64 is covered with a tape 90 and / or a resin member 96 (see Figs. 5 and 6). This prevents water and the like from seeping through the surface 64a of the welded joint 64. In other words, water and the like is prevented from penetrating through the surface 64a of the welded joint 64 and coming into contact with the first conductive member 70 and the second conductive member 80, which are made of different kinds of metals. Therefore, corrosion of the first conductive member 70 to the second conductive member 80 can be suppressed.

[0041] As shown in FIG. 3 and FIG. 4, here, the tape 90 is disposed inside the second region 74 of the upper surface 70u of the first conductive member 70, and is attached to the horizontal region 75 (in other words, the tape 490 and the horizontal region 75 are in contact). This results in a structure in which the tape 90 covers the surface 64a of the welded joint 64. This makes it possible to suitably prevent water and the like from seeping in from the surface 64a of the welded joint 64. In addition, as will be described in detail later, this configuration allows, for example, when a plurality of batteries 100 are electrically connected to each other to fabricate a battery pack 140 (see FIG. 7), when the bus bar 120 (see FIGS. 7 and 8) is disposed on the upper surface 70u of the first conductive member 70, the tape 90 does not interfere with the arrangement. This allows the first conductive member 70 and the bus bar 120 to be stably connected to each other.

[0042] The tape 90 and / or the resin member 96 (see FIGS. 5 and 6) are preferably arranged so as to be in contact with the surface 64a of the welded joint 64. As shown in FIGS. 3 and 4, the tape 90 is arranged so as to be in contact with the surface 64a of the welded joint 64. This makes it possible to more suitably prevent water and the like from seeping through the surface 64a of the welded joint 64. However, the tape 90 and / or the resin member 96 do not necessarily need to be in contact with the surface 64a of the welded joint 64. It is sufficient that the surface 64a of the welded joint 64 is covered with the tape 90 and / or the resin member 96.

[0043] The types of tape 90 include, for example, a base material coated with a glue material, a heat-sealed tape, etc. Examples of the base material include polyimide resin (e.g., Kapton (registered trademark), etc.), fluorine-based resin (e.g., Teflon (registered trademark), Nitoflon (registered trademark), etc.), polyester, etc. Examples of the glue material include silicon-based adhesives and acrylic-based adhesives, and silicon-based adhesives are preferably used from the viewpoints of heat resistance, durability, electrical insulation, etc. As the heat-sealed tape, polyester resins and fluorine-based resins are preferably used.

[0044] Here, a terminal including a resin member 96 in the present disclosure will be described with reference to a negative electrode terminal 260 according to a second embodiment. Fig. 5 is a vertical cross-sectional view that shows a schematic view of a main part of the negative electrode terminal 260 according to the second embodiment. Fig. 6 is a plan view that shows a schematic view of a main part of the negative electrode terminal 260 according to the second embodiment. The negative electrode terminal 260 may be the same as the negative electrode terminal 60 described above, except that the negative electrode terminal 260 includes a resin member 96 instead of the tape 90.

[0045] As shown in Figs. 5 and 6, here, the resin member 96 is disposed in the horizontal region 75. Here, the resin member 96 is doughnut-shaped. This results in a structure in which the resin member 96 covers the surface 64a of the welded joint 64. This makes it possible to suitably prevent water and the like from seeping in through the surface 64a of the welded joint 64. Note that it is sufficient for the resin member 96 to be disposed so as to cover the surface 64a of the welded joint 64, and it is not necessary for the resin member 96 to be disposed so as to completely fill the through hole 72 (in other words, the entire first region 73 and the second region 74).

[0046] The type of the resin member 96 is not limited unless otherwise specified, but from the viewpoint of heat resistance and electrical insulation, for example, epoxy resin is used, and ultraviolet curing epoxy resin and two-part mixed epoxy resin are preferably used.

[0047] As described above, the negative electrode terminal 60 includes the tape 90 and / or the resin member 96 (see FIGS. 5 and 6). This prevents water and the like from seeping in through the surface 64a of the welded joint 64 when a crack occurs in the welded joint 64. That is, water and the like is prevented from entering through the surface 64a of the welded joint 64 and coming into contact with the first conductive member 70 and the second conductive member 80, which are made of different types of metal. This makes it possible to suppress corrosion of the first conductive member 70 to the second conductive member 80.

[0048] <Method of Manufacturing Negative Electrode Terminal 60> Although not particularly limited, the negative electrode terminal 60 can be manufactured by a manufacturing method that includes, for example, preparing the first conductive member 70 and the second conductive member 80 as described above, and performing a conductive member connecting step and a welded joint covering step, typically in this order. However, the manufacturing method disclosed herein may further include other steps at any stage. In addition, the welded joint covering step may be performed at any timing when manufacturing the battery 100.

[0049] In the conductive member connecting step, the first conductive member 70 and the second conductive member 80 are electrically connected. The conductive member connecting step includes at least a welding step as a sub-step. In some preferred embodiments, the conductive member connecting step may further include a fastening step as a sub-step. The fastening step and the welding step may be performed in the reverse order, or may be performed substantially simultaneously.

[0050] In the welding and joining process, the horizontal region 75 of the first conductive member 70 and the flange portion 81 of the second conductive member 80 are joined by welding to form the welded joint 64. By performing the welding and joining process after the fastening process, the welded joint 64 with a stable shape can be formed with high accuracy. The welded joint 64 can be formed, for example, by welding the portion where the horizontal region 75 of the first conductive member 70 and the flange portion 81 of the second conductive member 80 are stacked so as to penetrate the horizontal region 75. Gas and heat generated during welding are released and diffused from the through hole 72. In this way, the through hole 72 can prevent gas and heat from accumulating between the horizontal region 75 and the flange portion 81. By welding, the welded joint 64 with high strength can be stably formed.

[0051] In the fastening step, the first conductive member 70 and the flange portion 81 of the second conductive member 80 are mechanically fixed to each other to form the fastening portion 62. The fastening portion 62 can be formed, for example, by inserting the constricted portion 84 of the second conductive member 80 into the recess 77 of the first conductive member 70, and deforming the recess 77 of the first conductive member 70 along the outer shape of the constricted portion 84 of the second conductive member 80 to fix the inner wall of the recess 77 with the second conductive member 80. This can improve the strength of the fastening portion 62. In some preferred embodiments, the fastening portion 62 is formed by fitting the recess 77 of the first conductive member 70 and the constricted portion 84 of the second conductive member 80 together. For example, the fastening portion 62 can be formed by horizontally press-fitting the constricted portion 84 of the second conductive member 80 into the recess 77 of the first conductive member 70. This can improve the workability of the fastening step.

[0052] In some preferred embodiments, the welded joint 64 is formed on the inner periphery side of the fastening portion 62. This makes the joint less likely to shift, improving the workability of the welding process. In addition, when the welded joint 64 is formed by welding, the welded portion is less likely to wobble, improving the weldability. Furthermore, when the horizontal region 75 is welded, less energy is required, improving the weldability.

[0053] In the weld joint covering step, the surface 64a of the weld joint 64 is covered with a tape 90 and / or a resin member 96. This step includes at least one sub-step selected from a tape application step and a resin member arrangement step.

[0054] In the tape application step, the tape 90 is applied to the negative electrode terminal 60 so as to cover the surface 64a of the welded joint 64. In some preferred embodiments, the tape 90 is applied to the first conductive member 70 (specifically, the upper surface 70u of the first conductive member 70). In other words, it is preferable to apply the tape 90 so that at least a portion of the tape 90 and the first conductive member 70 come into contact with each other. This causes the surface 64a of the welded joint 64 to be covered with the tape 90. Therefore, when a crack occurs in the welded joint 64, it is possible to prevent water or the like from seeping in through the surface 64a of the welded joint 64 and to suppress corrosion of the first conductive member 70 to the second conductive member 80.

[0055] When a base material coated with adhesive is used, the tape 90 is attached, for example, by aligning at least a portion of the surface of the tape coated with adhesive with the upper surface 70u of the first conductive member 70. When a thermal adhesive tape is used as the tape 90, for example, the tape 90 is placed on the upper surface 70u of the first conductive member 70 and heated. As a result, the tape 90 melts due to the heat and is welded to the upper surface 70u of the first conductive member 70, thereby fixing the tape 90 to the first conductive member 70. The method of welding the tape 90 is not particularly limited, and a known method can be appropriately selected depending on the material of the tape 90, etc.

[0056] In the resin member arrangement step, a resin member 96 is arranged on the negative electrode terminal 60 so as to cover the surface 64a of the welded joint 64. In some preferred embodiments, the resin member 96 is arranged in the through hole 72. As a result, the surface 64a of the welded joint 64 is covered with the resin member 96. Therefore, when a crack occurs in the welded joint 64, it is possible to prevent water or the like from seeping in through the surface 64a of the welded joint 64 and to suppress corrosion of the first conductive member 70 to the second conductive member 80. Here, the resin member 96 used in the resin member arrangement step is in a liquid or semi-solid state.

[0057] In some embodiments, the resin member arrangement step may further include a resin member curing step. The method for curing the resin member 96 is not particularly limited, but when a two-liquid mixed resin is used, a method of curing by mixing a curing agent with the resin base is preferably used, and when an ultraviolet curing resin is used, a method of curing by irradiating the resin member 96 with ultraviolet light to cause a photopolymerization reaction is preferably used. However, the resin member curing step may be omitted. That is, it is not necessarily required to cure the resin member 96.

[0058] <Manufacturing method of battery 100> The battery 100 is characterized by using the positive electrode terminal 50 and / or the negative electrode terminal 60 manufactured by the manufacturing method as described above. The rest of the manufacturing process may be the same as in the past. The battery 100 can be manufactured by, for example, preparing the electrode body 1, the electrolyte, the case main body 22, the sealing plate 30, the positive electrode terminal 50, and the negative electrode terminal 60 as described above, and by a manufacturing method including an attachment step and a joining step.

[0059] In the attachment step, the positive electrode terminal 50, the positive electrode current collector 8, the negative electrode terminal 60, and the negative electrode current collector 10 are attached to the sealing plate 30. The negative electrode terminal 60 and the negative electrode current collector 10 are fixed to the sealing plate 30 by crimping (riveting), for example, as shown in FIG. 3. The crimping is performed by sandwiching the gasket 40 between the negative electrode terminal 60 and the sealing plate 30, and further sandwiching the insulator 46 between the sealing plate 30 and the negative electrode current collector 10. In detail, the connection portion 88 of the negative electrode terminal 60 before crimping is passed through the cylindrical portion 41 of the gasket 40, the terminal attachment hole 32 of the sealing plate 30, the through hole 48 of the insulator 46, and the through hole 14 of the negative electrode current collector 10 in this order from above the sealing plate 30, and protrudes downward from the sealing plate 30. Then, the connection portion 88 protruding downward from the sealing plate 30 is crimped so that a compressive force is applied in the vertical direction Z. As a result, a rivet portion 66 is formed at the tip portion (the lower end portion in FIG. 3) of the connection portion 88 of the negative electrode terminal 60. In addition, during the crimping process, a compressive force is applied in the vertical direction Z, and the air existing between the first conductive member 70 and the second conductive member 80 is released from the through hole 72 of the first conductive member 70. This improves the adhesion between the first conductive member 70 and the second conductive member 80. That is, for example, even if water or the like penetrates between the first conductive member 70 and the second conductive member 80, it is difficult for the water to penetrate over a wide area.

[0060] By such a crimping process, the base 43 of the gasket 40 and the flat portion of the insulator 46 are compressed, and the gasket 40, the sealing plate 30, the insulator 46, and the negative electrode current collector 10 are fixed integrally to the sealing plate 30, and the terminal mounting hole 32 is sealed. The method of attaching the positive electrode terminal 50 and the positive electrode current collector 8 may be the same as that of the negative electrode terminal 60 and the negative electrode current collector 10 described above. The negative electrode current collector 10 is joined to the negative electrode current collector foil exposed portion of the negative electrode current collector foil 4, and the negative electrode of the electrode body 1 and the negative electrode terminal 60 are electrically connected. Similarly, the positive electrode current collector 8 is joined to the positive electrode current collector foil exposed portion of the positive electrode current collector foil 2, and the positive electrode of the electrode body 1 and the positive electrode terminal 50 are electrically connected. As a result, the sealing plate 30, the positive electrode terminal 50, the negative electrode terminal 60, and the electrode body 1 are integrated.

[0061] In the joining step, the electrode body 1 integrated with the sealing plate 30 is housed in the internal space of the case body 22, and the case body 22 and the sealing plate 30 are sealed. The sealing can be performed by welding such as laser welding. Thereafter, a nonaqueous electrolyte is injected from a liquid injection hole (not shown), and the liquid injection hole is closed to hermetically seal the battery 100. In this manner, the battery 100 can be manufactured.

[0062] In a preferred embodiment disclosed herein, a battery 100 includes an electrode assembly 1 including a positive electrode and a negative electrode, a battery case 20, a positive electrode current collector 8 electrically connected to the positive electrode, and a negative electrode current collector 10 electrically connected to the negative electrode. Furthermore, the battery case 20 (specifically, a sealing plate 30) has a terminal attachment hole 32, and a second conductive member 80 has a flange portion 81 at one end and a connection portion 88 at the other end. The flange portion 81 is connected to a first conductive member 70, and the first conductive member 70 is disposed outside the battery case 20. Meanwhile, the connection portion 88 of the second conductive member 80 passes through the terminal attachment hole 32 and is connected to the negative electrode current collector 10 inside the battery case 20.

[0063] Although the battery 100 can be used for various purposes, it can be suitably used in applications where water or the like may come into contact with the negative electrode terminal 60 and the positive electrode terminal 50 during use, typically as a power source (driving power source) for motors mounted on various vehicles, such as passenger cars, trucks, etc. The type of vehicle is not particularly limited, and examples include plug-in hybrid vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0064] As shown in Fig. 7, the battery 100 can also be suitably used as an assembled battery 140 in which a plurality of batteries 100 are electrically connected to one another via a bus bar 120. In this case, the plurality of batteries 100 can be electrically connected to one another by bridging, for example, a flat bus bar 120 across the first conductive member 70 (specifically, the upper surface 70u of the first conductive member 70). The bus bar 120 is made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The bus bar 120 and the first conductive member 70 can be electrically connected to one another by welding, for example, laser welding.

[0065] In the technology disclosed herein, the bus bar 120 is preferably disposed on the portion covered with the tape 90 and / or the resin member 96. When the bus bar 120 is disposed in this configuration, it is preferable that the resin member 96 (and / or the tape 90) is entirely disposed within the through hole 72 (i.e., does not protrude from the through hole 72). FIG. 8 is a vertical cross-sectional view that shows a schematic view of a main portion of the bus bar 120 disposed on the negative electrode terminal 360 according to the third embodiment. The negative electrode terminal 360 may be similar to the negative electrode terminal 60 described above, except that the negative electrode terminal 360 includes a resin member 396 instead of the tape 90. As shown in FIG. 8, the resin member 396 is disposed so as to fill the first region 73 and cover a part of the horizontal region 75. On the other hand, the resin member 396 is not disposed outside the through hole 72 (outer edge portion of the second region 74). The bus bar 120 is disposed in contact with the upper surface 70u of the first conductive member 70 so as to cover the resin member 396. This stabilizes the connection between the negative terminal 360 and the bus bar 120. However, the bus bar 120 may be disposed at the extension portion (the left end in FIG. 4) of the first conductive member 70. In this case, when tape 90 is attached to the outer periphery of the through hole 72 on the upper surface 70u of the first conductive member 70, this is preferable because it does not interfere with bus bar welding.

[0066] Although several embodiments of the technology disclosed herein have been described above, the above embodiments are merely examples. The technology disclosed herein can be implemented in various other forms. The technology disclosed herein can be implemented based on the contents disclosed in this specification and the technical common sense in the field. The technology described in the claims includes various modifications and changes to the above-exemplified embodiments. For example, it is possible to replace a part of the above-mentioned embodiment with another modified form, and it is also possible to add another modified form to the above-mentioned embodiment. Furthermore, if the technical feature is not described as essential, it is also possible to delete it as appropriate.

[0067] For example, in the first embodiment described above, the tape 90 is disposed so as to be in contact with the surface 64a of the welded joint 64. However, this is not limiting. The tape 90 does not necessarily need to be in contact with the surface 64a of the welded joint 64.

[0068] FIG. 9 is a vertical cross-sectional view showing a main part of a negative electrode terminal 460 according to a fourth embodiment. FIG. 10 is a plan view showing a main part of a negative electrode terminal 460 according to a fourth embodiment. The negative electrode terminal 460 may be similar to the negative electrode terminal 60 described above, except that the negative electrode terminal 460 includes a tape 490 instead of the tape 90. As shown in FIG. 9 and FIG. 10, the tape 490 is attached to the outer edge of the second region 74 (in other words, the outer periphery of the through hole 72) of the upper surface 70u of the first conductive member 70 while covering the surface 64a of the welded joint 64. In other words, at least a part of the tape 490 is disposed in contact with the upper surface 70u of the first conductive member 70. According to this configuration, the tape 490 and the surface 64a of the welded joint 64 are separated from each other. This can reduce the thermal effect of the welded joint 64 on the tape 490 when the welded joint 64 becomes hot during rapid high-current charging and discharging. Moreover, such a configuration is preferable because when bus bar 120 is disposed at the extension portion (the left end in FIG. 4) of first conductive member 70 of negative terminal 460, it does not interfere with bus bar welding.

[0069] For example, in the first embodiment described above, the first conductive member 70 includes the through hole 72. However, this is not limited to this. In the technology disclosed herein, the through hole 72 is not essential, and may be omitted in other embodiments.

[0070] FIG. 11 is a vertical cross-sectional view showing a main part of a negative terminal 560 according to the fifth embodiment. FIG. 12 is a plan view showing a main part of a negative terminal 560 according to the fifth embodiment. The negative terminal 560 may be similar to the negative terminal 60 described above, except that it includes a first conductive member 570 and a welded joint 564, and includes a resin member 596 instead of the tape 90. As shown in FIG. 11 and FIG. 12, the first conductive member 570 has a lower surface 570d and an upper surface 570u, and includes a thin-walled portion 78 (see FIG. 11 and FIG. 12) recessed (thinly formed) from the upper surface 570u of the first conductive member 570 instead of a through hole. The thin-walled portion 78 is formed in an annular shape (for example, a circular ring shape) in a plan view. The welded joint 564 is provided in the thin-walled portion 78. This requires less energy during joining, and improves weldability. Resin member 596 is disposed so as to cover surface 564a of welded joint 564. Here, resin member 596 is formed in a doughnut shape. This makes it possible to cover surface 564a of welded joint 564 with a small amount of resin member 596.

[0071] FIG. 13 is a vertical cross-sectional view showing a main part of the negative terminal 660 according to the sixth embodiment. FIG. 14 is a plan view showing a main part of the negative terminal 660 according to the sixth embodiment. The negative terminal 660 may be similar to the negative terminal 560 according to the fifth embodiment, except that the negative terminal 660 includes a resin member 696 instead of the resin member 596. Here, the resin member 696 has a substantially circular shape and is arranged so as to cover the surface 564a of the welded joint 564. According to this configuration, the resin member 696 covers the surface 564a of the welded joint 564 more reliably. This makes it possible to omit confirmation by image inspection as to whether the resin member 696 covers the surface 564a of the welded joint 564.

[0072] 8, in the third embodiment, the resin member 396 is disposed so as to fill the first region 73 and cover a part of the horizontal region 75. With this configuration, the resin member 396 covers the welded joint 64 and further covers the boundary portion 76 which is the abutting portion between the lower end of the through hole 72 (first region 73) and the second conductive member 80. This prevents water and the like from seeping in from the surface 64a of the welded joint 64 and prevents water and the like from contacting the first conductive member 70 and the second conductive member 80 through the boundary portion 76. Therefore, corrosion of the first conductive member 70 to the second conductive member 80 is more suitably suppressed.

[0073] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Item 1: A terminal comprising a first conductive member, a second conductive member electrically connected to the first conductive member, and a welded joint that welds the first conductive member and the second conductive member, wherein the first conductive member and the second conductive member are made of different types of metals, and the welded joint is formed to penetrate the first conductive member and reach the second conductive member, and wherein a surface of the welded joint is covered with tape and / or a resin member. Item 2: A terminal as described in item 1, wherein the first conductive member is plate-shaped, the second conductive member has a flange portion, and has a fastening portion that mechanically fixes the first conductive member and the flange portion. Item 3: The terminal according to item 2, wherein the first conductive member has a recess that accommodates at least a portion of the flange portion. Item 4: The terminal according to any one of items 1 to 3, wherein the first conductive member has a through hole. Item 5: The terminal described in item 4, wherein the through hole includes a first region and a second region, the first region has a smaller diameter than the second region, and the first region is positioned closer to the second conductive member than the second region. Item 6: The terminal according to any one of items 1 to 5, wherein the tape is attached to the first conductive member. Item 7: The terminal according to any one of items 4 to 6, wherein the resin member is disposed in the through hole. Item 8: A battery having an electrode assembly including the terminal according to any one of items 1 to 7, a positive electrode, and a negative electrode, and a battery case that houses the electrode assembly, the battery including a current collector electrically connected to the positive electrode or the negative electrode, the battery case having a terminal mounting hole, the second conductive member having a flange portion at one end and a connection portion at the other end, the flange portion being connected to the first conductive member, the first conductive member being disposed outside the battery case, and the connection portion of the second conductive member penetrating the terminal mounting hole of the battery case and connected to the current collector inside the battery case. [Explanation of symbols]

[0074] 1 Electrode body 8 Positive electrode current collector 10 Negative electrode current collector 20 Battery case 22 Case body 30 Sealing plate 32 Terminal mounting hole 50 Positive terminal 60, 260, 360, 460, 560, 660 negative terminal 62 Fastening Part 64, 564 Welded joints 64a, 564a Surface of welded joint 70, 570 First conductive member 72 Through hole 73 First area 74 Second area 75 horizontal area 76 Boundary 77 Recess 78 Thin Section 80 Second conductive member 81 Flange 88 Connection 90, 490 Tape 96, 396, 596, 696 Resin parts 100 batteries 120 Busbar 140 Battery pack

Claims

1. A first conductive member; a second conductive member electrically connected to the first conductive member; a welded joint portion that welds the first conductive member and the second conductive member together; A terminal comprising: the first conductive member and the second conductive member are made of different metals; The welded joint is formed to penetrate the first conductive member and reach the second conductive member, the first conductive member has a recess on a surface opposite to a surface that contacts the second conductive member, No through hole is formed in the bottom of the recess, The weld joint is formed so as to penetrate a bottom of the recess, Here, the surface of the welded joint, which is located within the recess, is covered with tape and / or a resin member.

2. The first conductive member is plate-shaped, the second conductive member has a flange portion, The terminal according to claim 1 , further comprising a fastening portion for mechanically fixing the first conductive member and the flange portion together.

3. The terminal according to claim 2 , wherein the first conductive member has a recess that receives at least a portion of the flange portion.

4. The terminal of claim 1 , wherein the tape is attached to the first conductive member.

5. A first conductive member; a second conductive member electrically connected to the first conductive member; a welded joint portion that welds the first conductive member and the second conductive member together; A terminal comprising: the first conductive member and the second conductive member are made of different metals; The welded joint is formed to penetrate the first conductive member and reach the second conductive member, the first conductive member has a recess on a surface opposite to a surface that contacts the second conductive member, The welded joint is formed at the bottom of the recess, Here, tape is attached around the recess of the first conductive member, the surface of the weld joint is covered with the tape; A terminal for a battery, wherein the tape is spaced from a surface of the weld joint.

6. A first conductive member; a second conductive member electrically connected to the first conductive member; a welded joint portion that welds the first conductive member and the second conductive member together; A terminal comprising: the first conductive member and the second conductive member are made of different metals; The welded joint is formed to penetrate the first conductive member and reach the second conductive member, The welded joint is formed into a double or more circular or spiral shape in a plan view, Here, the surface of the welded joint is covered with tape and / or a resin member.

7. A first conductive member; a second conductive member electrically connected to the first conductive member; a welded joint portion that welds the first conductive member and the second conductive member together; A terminal comprising: the first conductive member and the second conductive member are made of different metals; The welded joint is formed to penetrate the first conductive member and reach the second conductive member, Here, the surface of the welded joint is covered with tape and / or a resin member, A terminal for a battery, wherein the tape and / or resin member is formed in a doughnut shape.

8. A battery comprising the terminal according to any one of claims 1 to 7.

Images