Battery unit, battery unit manufacturing method, electronic device, power tool, and electric vehicle

Abstract

This battery unit has improved waterproofness.　The battery unit is provided with a battery having a terminal unit, a conductive member electrically connected to the terminal unit and having a first main surface and a second main surface, and a first insulation film arranged on at least the first main surface side of the conductive member; the first insulation film has an opening, the conductive member is exposed through the opening, and further, a cushion member is provided arranged surrounding the terminal unit, between the conductive member and the periphery around the end surface where the terminal unit is formed.

Description

[Technical Field]

[0001] The present invention relates to a battery unit, a method for manufacturing a battery unit, an electronic device, a power tool, and an electric vehicle. [Background technology]

[0002] In a battery unit including multiple batteries such as lithium-ion batteries, the multiple batteries are electrically connected by tabs, as described in Patent Document 1, for example. It is important to ensure the waterproofing of the batteries in such a battery unit. For example, Patent Document 2 listed below discloses a technique in which a water-absorbent waterproof ring is placed around the battery terminals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-134336

[0004] [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-196277 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 lacks consideration for waterproofing. Specifically, because openings are provided in the tabs, there is a risk of moisture entering through the openings. Furthermore, the technology described in Patent Document 2 uses a water-absorbent waterproof ring, which traps moisture between the battery and the tab, increasing the risk of short circuits due to migration. Furthermore, the technology described in Patent Document 2 places waterproof rings individually on each battery, which may result in misalignment during assembly or an increase in assembly man-hours.

[0006] Therefore, an object of the present invention is to provide a battery unit with improved waterproofing and a method for manufacturing the battery unit, as well as an electronic device, a power tool, and an electric vehicle that include the battery unit. [Means for solving the problem]

[0007] The present invention provides a battery having end faces at both ends and terminal portions formed on the end faces; a conductive member electrically connected to the terminal portion and having a first main surface and a second main surface; a first insulating film disposed on at least the first main surface side of the conductive member; a second insulating film disposed on at least the second main surface side of the conductive member; Equipped with The first insulating film and the second insulating film are heat-sealed together, The first insulating film is 1st An opening is provided, the second insulating film has a second opening at least at a position opposite to the first opening; Conductive material 1st opening and a second opening It is exposed through Further, a cushion member is provided between the peripheral edge of the end surface on which the terminal portion is formed and the conductive member so as to surround the terminal portion, The cushion member is attached to the second insulating film. It is a battery unit. [Effects of the Invention]

[0008] According to at least the embodiments of the present invention, a battery unit or the like with improved waterproofing can be provided. Note that the effects exemplified in this specification should not be construed as limiting the scope of the present invention. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a lithium-ion battery according to one embodiment. [Figure 2] FIG. 2 is a perspective view of a battery unit according to one embodiment. [Figure 3] FIG. 3 is a side view of the battery unit according to one embodiment. [Figure 4] FIG. 4 is a partially exploded perspective view of a battery unit according to one embodiment. [Figure 5] FIG. 5 is a perspective view including an exploded state of the first tab sheet assembly according to one embodiment. [Figure 6] FIG. 6 is an exploded perspective view of the second tab sheet assembly according to one embodiment. [Figure 7] FIG. 7 is a diagram illustrating a first cushion member according to one embodiment. [Figure 8] 8A to 8C are diagrams illustrating a first cushion member according to one embodiment. [Figure 9] 9A and 9B are diagrams illustrating a tab according to one embodiment. [Figure 10] 10A and 10B are diagrams illustrating an insulating film according to one embodiment. [Figure 11] 11A and 11B are diagrams showing the state in which two insulating films are heat-sealed together. [Figure 12] FIG. 12 is a cross-sectional view of the configuration shown in FIG. 11 taken along the line AA-AA. [Figure 13] FIG. 13 is a perspective view showing a state in which the cushion member and the tab sheet assembly are integrated together. [Figure 14] 14A to 14D are diagrams to be referred to when describing a method for manufacturing a battery unit according to one embodiment. [Figure 15] 15A and 15B are diagrams to be referred to when describing a method for manufacturing a battery unit according to one embodiment. [Figure 16] FIG. 16 is a diagram to be referred to when describing a manufacturing method of a battery unit according to one embodiment. [Figure 17]17A and 17B are diagrams to be referred to when describing a method for manufacturing a battery unit according to one embodiment. [Figure 18] FIG. 18 is a diagram that is referred to when explaining specific examples of numerical values ​​in a battery unit according to one embodiment. [Figure 19] FIG. 19 is a diagram that is referred to when explaining specific examples of numerical values ​​in a battery unit according to one embodiment. [Figure 20] FIG. 20 is a diagram that is referred to when explaining specific examples of numerical values ​​in a battery unit according to one embodiment. [Figure 21] FIG. 21 is a diagram for explaining a modified example. [Figure 22] FIG. 22 is a diagram for explaining a modified example. [Figure 23] FIG. 23 is a diagram for explaining a modified example. [Figure 24] FIG. 24 is a diagram for explaining a modified example. [Figure 25] FIG. 25 is a diagram for explaining a modified example. [Figure 26] FIG. 26 is a diagram for explaining a modified example. [Figure 27] 27A and 27B are diagrams for explaining a modified example. [Figure 28] 28A and 28B are diagrams for explaining a modified example. [Figure 29] 29A and 29B are diagrams for explaining a modified example. [Figure 30] 30A and 30B are diagrams for explaining a modified example. [Figure 31] FIG. 31 is a diagram for explaining an application example of the present invention. [Figure 32] FIG. 32 is a diagram for explaining an application example of the present invention. [Figure 33] FIG. 33 is a diagram for explaining an application example of the present invention. [Figure 34] FIG. 34 is a diagram for explaining an application example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The description will be made in the following order. <One embodiment> <Modification> <Application example> The embodiments and the like described below are preferred specific examples of the present invention, and the content of the present invention is not limited to these embodiments and the like. Note that the components described in the claims are not limited to those described in the embodiments. In particular, unless otherwise specified, the dimensions, materials, shapes, relative positions, and directions (up, down, left, right, etc.) of the components described in the embodiments are not intended to limit the scope of the present invention, but are merely illustrative examples. The sizes and relative positions of the components shown in the drawings may be exaggerated for clarity, and only some reference numerals may be shown or some parts may be simplified to avoid cluttering the illustrations. Furthermore, in the following description, the same names and numerals indicate the same or similar components, and redundant explanations will be omitted as appropriate. Furthermore, the components constituting the present invention may be configured with the same components, so that one component serves multiple functions, or conversely, the function of one component may be shared by multiple components.

[0011] <One embodiment> In this specification, one or more battery cells (single cells) electrically connected by conductive members (tabs, described later) are referred to as a battery unit, and a battery unit packaged in an outer case and connected to a control board on which a control IC (Integrated Circuit) that performs protection operations, etc. is mounted is referred to as a battery pack.

[0012] [Example of a battery] First, an example of a battery that can be used in the battery unit according to this embodiment will be described. In this embodiment, a cylindrical lithium ion battery 1 is used as the battery. Of course, batteries other than lithium ion batteries may also be used.

[0013] 1 is a schematic cross-sectional view of a lithium-ion battery 1. The lithium-ion battery 1 includes a pair of insulating plates 12 and 13 and an electrode winding body 20 inside a cylindrical battery can 11. The lithium-ion battery 1 may further include, inside the battery can 11, one or more of a thermal resistor (Positive Temperature Coefficient Thermal-Resistor or PTC) and a reinforcing member (not shown).

[0014] (battery can) The battery can 11 is a member that mainly houses the electrode winding body 20. The battery can 11 is a cylindrical container with one end open and the other end closed. That is, the battery can 11 has one open end (open end 11N). The battery can 11 contains one or more types of metal materials such as iron, aluminum, and alloys thereof. The surface of the battery can 11 may be plated with one or more types of metal materials such as nickel.

[0015] (insulating plate) The insulating plates 12 and 13 are sheet-like members having surfaces that are approximately perpendicular to the winding axis direction of the electrode winding body 20 (the vertical direction in FIG. 1). The insulating plates 12 and 13 are arranged so as to sandwich the electrode winding body 20 between them. Materials that can be used for the insulating plates 12 and 13 include polyethylene terephthalate (PET), polypropylene (PP), and bakelite. Bakelite includes paper bakelite and cloth bakelite, which are made by applying phenolic resin to paper or cloth and then heating it.

[0016] (Caulking structure) A battery lid 14 and a safety valve mechanism 18 are crimped to the open end 11N of the battery can 11 via a gasket 15, forming a crimp structure 11R. A crimp portion 11P is formed at the top of the crimp structure 11R (the top in the vertical direction in FIG. 1). The crimp portion 11P is also referred to as the top of the crimp portion. The crimp structure 11R seals the battery can 11 with the electrode wound body 20 and other components housed inside.

[0017] (Battery cover) The battery lid 14 is a member that closes the open end 11N of the battery can 11 when the electrode winding body 20 and other components are housed inside the battery can 11. The battery lid 14 contains the same material as the material from which the battery can 11 is formed. A central region of the battery lid 14 protrudes in the vertical direction in FIG. 1. Meanwhile, the region of the battery lid 14 other than the central region (peripheral region) is in contact with the safety valve mechanism 18.

[0018] (gasket) The gasket 15 is a member that is mainly interposed between the periphery of the crimped portion 11P of the battery can 11 and the battery lid 14, thereby sealing the gap between the periphery of the crimped portion 11P and the battery lid 14. The surface of the gasket 15 may be coated with, for example, asphalt.

[0019] The gasket 15 contains an insulating material. The type of insulating material is not particularly limited, but a polymer material such as polybutylene terephthalate (PBT) or polypropylene (PP) is preferable. This is because the gasket 15 can electrically isolate the battery can 11 and the battery lid 14 from each other while sufficiently sealing the gap between the periphery of the crimped portion 11P and the battery lid 14.

[0020] (Safety valve mechanism) The safety valve mechanism 18 mainly releases the internal pressure of the battery can 11 when the pressure inside the battery can 11 (internal pressure) increases, by releasing the sealed state of the battery can 11 as necessary. The increase in the internal pressure of the battery can 11 can be caused by gas generated due to the decomposition reaction of the electrolyte solution during charging and discharging.

[0021] (Electrode winding body) In the cylindrical lithium-ion battery 1, a strip-shaped positive electrode 21 and a strip-shaped negative electrode 22 are spirally wound with a separator 23 sandwiched therebetween and housed in a battery can 11 in a state impregnated with an electrolyte. Although not shown, the positive electrode 21 and the negative electrode 22 are formed by forming a positive electrode active material layer and a negative electrode active material layer on one or both sides of the positive electrode foil and the negative electrode foil, respectively. The material of the positive electrode foil is a metal foil containing aluminum or an aluminum alloy. The material of the negative electrode foil is a metal foil containing nickel, a nickel alloy, copper, or a copper alloy. The separator 23 is a porous, insulating film that electrically insulates the positive electrode 21 and the negative electrode 22 while allowing lithium ions to move.

[0022] A space (central space 20C) is provided in the center of the electrode winding body 20 when the positive electrode 21, the negative electrode 22, and the separator 23 are wound, and a center pin 24 is inserted into the central space 20C. The center pin 24 may be omitted.

[0023] A positive electrode lead 25 is connected to the positive electrode 21. A negative electrode lead 26 is connected to the negative electrode 22. The positive electrode lead 25 contains a conductive material such as aluminum. The positive electrode lead 25 is connected to the safety valve mechanism 18 and electrically connected to the battery lid 14. With this configuration, a positive electrode terminal 31 is formed at one end of the lithium ion battery 1. The negative electrode lead 26 contains a conductive material such as nickel. The negative electrode lead 26 is connected to, for example, the bottom of the battery can 11 and is electrically connected to the battery can 11. With this configuration, a negative electrode terminal 32 is formed at the other end of the lithium ion battery 1. In other words, the lithium ion battery 1 is a battery having a positive electrode terminal 31 and a negative electrode terminal 32 as terminal portions. Note that when either the positive electrode terminal 31 or the negative electrode terminal 32 is acceptable, they may also be referred to as terminal portions.

[0024] The positive electrode 21, the negative electrode 22, and the separator 23 may be made of known materials.

[0025] [Example of battery unit configuration] (Overall configuration example) Next, a battery unit (battery unit 2) including the above-described lithium ion battery 1 will be described. Fig. 2 is a perspective view of the battery unit 2 according to one embodiment. Fig. 3 is a side view of the battery unit 2 according to one embodiment. Fig. 4 is a partially exploded perspective view of the battery unit 2 according to one embodiment. In this embodiment, the X-axis, Y-axis, and Z-axis are perpendicular to each other, and the X-axis and Y-axis are axes within a predetermined plane, and the Z-axis is an axis perpendicular to the predetermined plane. In the following description, the height direction of the lithium-ion battery 1 is defined as the Z-axis.

[0026] The battery unit 2 includes nine lithium ion batteries (lithium ion batteries 1A to 1I), a first cushion member 41, a first tab sheet assembly 42, a second cushion member 51, and a second tab sheet assembly 52. ​​As shown in FIG. 3, the battery unit 2 is generally configured such that the first cushion member 41 and the first tab sheet assembly 42 are disposed on one terminal side of the lithium ion battery 1, and the second cushion member 51 and the second tab sheet assembly 52 are disposed on the other terminal side of the lithium ion battery 1. When it is not necessary to distinguish between the individual lithium ion batteries, they will be collectively referred to as lithium ion battery 1.

[0027] (Lithium-ion battery placement) The nine lithium ion batteries 1 are arranged in three rows in the X axis direction, with three batteries arranged in one row in the Y axis direction. The nine lithium ion batteries 1 are electrically connected to each other via tabs, which will be described later. As shown in FIG. 4, lithium ion batteries 1A to 1C, which are arranged at the front end (closest to the origin) in the X axis direction, are arranged so that their positive electrode terminals 31 are on the upper side in the Z axis direction. Lithium ion batteries 1D to 1F, which are adjacent to lithium ion batteries 1A to 1C, are arranged so that their negative electrode terminals 32 are on the upper side in the Z axis direction. Lithium ion batteries 1G to 1I, which are adjacent to lithium ion batteries 1D to 1F, are arranged so that their positive electrode terminals 31 are on the upper side in the Z axis direction.

[0028] Of the nine lithium ion batteries 1, three lithium ion batteries 1A-1C, lithium ion batteries 1D-1F, and lithium ion batteries 1G-1I arranged in the Y-axis direction are connected in series. The three series-connected lithium ion batteries are then connected in parallel with each other. That is, in this embodiment, the nine lithium ion batteries 1 are connected in a three-in-three-in-parallel configuration. The nine lithium ion batteries 1 are electrically connected by tabs provided on the first tab sheet assembly 42 and the second tab sheet assembly 52, respectively.

[0029] Further, with reference to FIGS. 5 to 12, a detailed description will be given of an example configuration of the battery unit 2. FIG. 5 is an exploded perspective view of a first tab sheet assembly 42 according to an embodiment. FIG. 6 is an exploded perspective view of a second tab sheet assembly 52 according to an embodiment. FIG. 7 is a diagram illustrating a first cushion member according to an embodiment. FIGS. 8A to 8C are diagrams illustrating a first cushion member according to an embodiment. FIGS. 9A and 9B are diagrams illustrating a tab according to an embodiment. FIGS. 10A and 10B are diagrams illustrating an insulating film according to an embodiment. FIGS. 11A and 11B are diagrams illustrating two insulating films heat-sealed together. FIG. 12 is a cross-sectional view of the configuration shown in FIG. 11 taken along the cutting line AA-AA.

[0030] (Cushion material) First, the first cushion member 41 will be described. Note that the following description can also be applied to the second cushion member 51. Of course, this does not exclude structural differences between the first cushion member 41 and the second cushion member 51 within the scope of the gist of the present invention.

[0031] As shown in FIG. 7, the first cushion member 41 is a thin plate-like member with a substantially rectangular peripheral edge in a front view. The first cushion member 41 has nine holes (holes 411A to 41I) on the inside of the peripheral edge, the number of which corresponds to the number of lithium ion batteries 1. When it is not necessary to distinguish between the individual holes, they will be referred to as holes 411 as appropriate. Each of the holes 411A to 411I is provided at a position that exposes a terminal of the corresponding lithium ion battery 1. For example, the hole 411A is provided at a position that exposes the positive terminal 31 of the lithium ion battery 1A.

[0032] The first cushion member 41 is preferably a waterproof foam. Rubber materials such as silicone rubber and chloroprene rubber are generally used as waterproof cushion members. As will be described in detail later, the first cushion member 41 is compressed when the tab and the terminal are welded together. Silicone rubber and other materials have excessive hardness and resilience, increasing the risk of poor welding. Furthermore, rubber materials such as silicone rubber have a high specific gravity, which increases the overall weight of the battery unit 2. From this perspective, the first cushion member 41 is preferably a waterproof foam.

[0033] More preferably, the first cushion member 41 is a foam with a closed-cell structure or a foam with a semi-closed-cell structure. A closed-cell structure is a structure in which multiple cells (schematically shown by circles) present inside the member are independent of one another, as shown in FIG. 8A. A semi-closed-cell structure is a structure in which multiple cells present inside the member are basically independent of one another, but some cells are connected, as shown in FIG. 8B. In contrast, an open-cell structure is a structure in which almost all of the multiple cells present inside the member are connected, as shown in FIG. 8C.

[0034] A closed-cell foam or a semi-closed-cell foam has the property of not allowing liquids such as water to pass through to the other side when pressure is applied from one side and compressed. In contrast, an open-cell foam has the property of allowing liquids such as water to pass through to the other side when pressure is applied from one side and compressed. Foams of either type can be distinguished by, for example, dropping water onto one side of the foam and then compressing it, and checking whether or not water penetrates to the other side. If water does not penetrate, the foam has a closed-cell structure or a semi-closed-cell structure, and if water penetrates, the foam has an open-cell structure.

[0035] (tab sheet assembly) Next, the tab sheet assembly will be described. As shown in Fig. 5, the first tab sheet assembly 42 includes tabs 43, insulating films 44, and insulating films 45. These are roughly arranged on the upper surface of the first cushion member 41 in the order of insulating film 45, tabs 43, and insulating film 44.

[0036] 6, the second tab sheet assembly 52 includes tabs 53, insulating films 54, and insulating films 55. These are roughly arranged on the bottom surface of the second cushion member 51 in the order of insulating film 54, tabs 53, and insulating film 55. The tabs 43 and 53 are examples of conductive members electrically connected to the terminal portions of the lithium-ion battery 1.

[0037] "tab" Next, a description will be given of the tabs 43 and 53. The tabs 43 and 53 are each made of a metal material such as aluminum (Al), copper (Cu), nickel (Ni), or stainless steel.

[0038] As shown in FIG. 9A, the tab 43 includes a tab 43A and a tab 43B. The tab 43A includes a lead-out portion 431A at its end, and three circular portions 431B, 431C, and 431D arranged in a straight line from the lead-out portion 431A. The tab 43B is a parallelogram-shaped tab. The tab 43A includes a top surface 432A and a bottom surface 432B, and the tab 43B includes a top surface 433A and a bottom surface 433B. As shown in FIG. 4, the circular portion 431B of the tab 43A is welded to the positive terminal 31 of the lithium-ion battery 1A, the circular portion 431C of the tab 43A is welded to the positive terminal 31 of the lithium-ion battery 1B, and the circular portion 431D of the tab 43A is welded to the positive terminal 31 of the lithium-ion battery 1C. Appropriate locations of tab 43B are welded to the negative electrode terminals 32 of lithium ion batteries 1D to 1F and the positive electrode terminals 31 of lithium ion batteries 1G to 1I. For example, resistance welding is used for this welding, in which a welding rod is pressed against top surface 432A of tab 43A and top surface 433A of tab 43B, and a current is passed through the welding rod to weld bottom surface 432B and bottom surface 433B to the terminal portions, respectively. Resistance welding leaves resistance weld marks on top surface 432A of tab 43A and top surface 433A of tab 43B.

[0039] As shown in FIG. 9B , tab 53 includes tab 53A and tab 53B. Tab 53A includes lead-out portion 531A at its end, and three circular portions 531B, 531C, and 531D arranged in a straight line starting from lead-out portion 531A. Tab 53B is a parallelogram-shaped tab. Tab 53A includes top surface 532A and bottom surface 532B, and tab 53B includes top surface 533A and bottom surface 533B. As shown in FIG. 4 , circular portion 531B of tab 53A is welded to negative terminal 32 of lithium-ion battery 1G, circular portion 531C of tab 53A is welded to negative terminal 32 of lithium-ion battery 1H, and circular portion 531D of tab 53A is welded to negative terminal 32 of lithium-ion battery 1I. Appropriate locations of tab 53B are welded to negative electrode terminal 32 of lithium ion batteries 1A to 1C and positive electrode terminal 31 of lithium ion batteries 1D to 1F. For example, resistance welding is used for this welding, in which a welding rod is pressed against bottom surface 532B of tab 53A and bottom surface 533B of tab 53B, and a current is passed through the welding rod to weld top surface 532A and top surface 533A to the terminal portions, respectively. Resistance welding leaves resistance weld marks on bottom surface 532B of tab 53A and bottom surface 533B of tab 53B.

[0040] The lead-out portion 431A is electrically connected to the positive output terminal of the battery pack including the battery unit 2. The lead-out portion 531A is electrically connected to the negative output terminal of the battery pack including the battery unit 2.

[0041] As described above, the tabs 43 and 53 according to this embodiment have a shape in which no opening is provided.

[0042] In this embodiment, the outer surfaces of tabs 43 and 53 correspond to the first main surfaces, and the inner surfaces correspond to the second main surfaces. Specifically, top surface 432A, top surface 433A, bottom surface 532B, and bottom surface 533B correspond to an example of the first main surfaces. Also, bottom surface 432B, bottom surface 433B, top surface 532A, and top surface 533A correspond to an example of the second main surfaces.

[0043] "Insulating film" Next, the insulating films 44 and 45 will be described with reference to Fig. 10. The following description is also applicable to the insulating films 54 and 55. Of course, this does not exclude structural differences between the insulating films 44 and 45 and the insulating films 54 and 55 within the scope of the present invention.

[0044] The insulating films 44 and 45 are, for example, heat-sealed films containing polyethylene terephthalate (PET). Each of the insulating films 44 and 45 has openings whose number corresponds to the number of lithium-ion batteries 1. For example, the insulating film 44 has nine openings 44A to 44I. Furthermore, the insulating film 45 has nine openings 45A to 45I that are provided at approximately the same positions as the openings 44A to 44I. These openings 44A to 44I and 45A to 45I are formed so that their positions in the Z-axis direction are approximately the same as those of the holes 411A to 41I of the first cushion member 41.

[0045] 5, insulating film 44 is disposed on the upper surface side of tab 43, and insulating film 45 is disposed on the bottom surface side of tab 43. Also, as shown in Fig. 6, insulating film 54 is disposed on the upper surface side of tab 53, and insulating film 55 is disposed on the bottom surface side of tab 53. That is, in this embodiment, insulating films 44 and 55 correspond to an example of a first insulating film, and insulating films 45 and 54 correspond to an example of a second insulating film.

[0046] The insulating films 44 and 45 are heat-sealed with the tabs 43A and 43B sandwiched between them at predetermined positions. FIGS. 11A and 11B show the insulating films 44 and 45 in a heat-sealed state. A circular portion 431B of the tab 43A is exposed to the outside through an opening 44A in the insulating film 44 (an opening 45A in the insulating film 45 on the opposite side). A circular portion 431C of the tab 43A is exposed to the outside through an opening 44B in the insulating film 44 (an opening 45B in the insulating film 45 on the opposite side). A circular portion 431D of the tab 43A is exposed to the outside through an opening 44C in the insulating film 44 (an opening 45C in the insulating film 45 on the opposite side). Furthermore, the tab 43B is exposed to the outside through openings 44D to 44I in the insulating film 44 (openings 45D to 45I in the insulating film 45 on the opposite side).

[0047] Although not shown, tab 53B is exposed to the outside through openings (openings corresponding to the positions of openings 44A to 44F and openings 45A to 45F) in insulating films 54 and 55. Tab 53A is exposed to the outside through openings (openings corresponding to the positions of openings 44G to 44I and openings 45G to 45I) in insulating films 54 and 55.

[0048] Fig. 12 is a cross-sectional view of the configuration shown in Fig. 11 taken along cutting line AA-AA. As shown in Fig. 12, insulating films 44 and 45 are heat-sealed in areas where tabs 43A and 43B are not present, forming seal portion 61 by heat fusion.

[0049] By adhering the above-described first tab sheet assembly 42 to the upper surface of the first cushion member 41 using adhesive or double-sided tape, the first tab sheet assembly 42 and the first cushion member 41 are integrated to form an integrated product, as shown in Fig. 13. The same applies to the second tab sheet assembly 52 and the second cushion member 51.

[0050] [Battery unit manufacturing method] Next, an example of a method for manufacturing the above-described battery unit 2 will be described with reference to FIGS.

[0051] 14A, tabs 43 (in this example, tabs 43A and 43B) are disposed between insulating films 44 and 45. For example, the openings of insulating film 44 and the openings of insulating film 45 are disposed so as to face each other, and each component is disposed so that tab 43 is present between the facing openings.

[0052] 14B, insulating film 44 and insulating film 45 are heat-sealed together, thereby forming first tab sheet assembly 42 in which insulating films 44, 45 and tab 43 are integrated together.

[0053] Next, as shown in Fig. 14C, the first tab sheet assembly 42 is attached to the upper surface of the first cushion member 41 using double-sided tape, thereby integrating the first cushion member 41 and the first tab sheet assembly 42 as shown in Fig. 14D. Note that the second tab sheet assembly 52 is formed in the same manner and is integrated with the second cushion member 51.

[0054] Next, the tab 43 is welded to the terminal portion of the lithium-ion battery 1. Furthermore, the tab 53 is welded to the terminal portion of the lithium-ion battery 1. A specific welding method will be described with reference to FIGS. 15A and 15B. FIGS. 15A and 15B show an example of welding the circular portion 431B of the tab 43A to the positive electrode terminal 31 of the lithium-ion battery 1A. Note that in FIGS. 15A and 15B, the configuration near the positive electrode terminal 31 is appropriately simplified.

[0055] For example, the above-described integrated first cushion member 41 and first tab sheet assembly 42 are placed against the peripheral edge of the end face where the terminal portion (positive terminal 31 in this example) of lithium ion battery 1A is formed. As a result, first cushion member 41, insulating film 45, tab 43, and insulating film 44 are placed in this order against the peripheral edge of the end face where the positive terminal 31 of lithium ion battery 1A is formed. When the terminal portion is positive terminal 31, the peripheral edge of the end face is a crimped portion 11P formed by crimping battery can 11, which is the exterior of lithium ion battery 1A.

[0056] When the integrated first cushion member 41 and first tab sheet assembly 42 are positioned, the tab 43 (specifically, the circular portion 431B of the tab 43A) and the positive terminal 31 of the lithium ion battery 1A face each other with a clearance SP therebetween, as shown in FIG. 15A.

[0057] Next, a welding rod WR is brought into contact with a portion of the tab 43A opposite the side facing the positive electrode terminal 31 (top surface 432A of the circular portion 431B of the tab 43A) and pressed in, thereby deforming the circular portion 431B. The stress caused by pressing the welding rod WR is transmitted to the first cushion member 41, compressing the first cushion member 41. By pressing the welding rod WR in while compressing the first cushion member 41, the vicinity of the circular portion 431B of the tab 43A comes into contact with the positive electrode terminal 31. By passing a current through the welding rod WR in this contact state, the vicinity of the circular portion 431B of the tab 43A and the positive electrode terminal 31 are welded together, as shown in FIG. 15B . In the welded state, the first cushion member 41 is disposed between the peripheral edge of the end face where the positive electrode terminal 31 is formed (the crimped portion 11P in this example) and the tab 43, so as to surround the positive electrode terminal 31. Furthermore, first cushion member 41 is sandwiched between caulking portion 11P and tab 43. Specifically, first cushion member 41 is sandwiched between caulking portion 11P and tab 43 so that the periphery of the opening of hole 411A of first cushion member 41 is compressed. Furthermore, resistance welding marks 71 are formed on upper surface 432A of circular portion 431B.

[0058] While the welding method is not limited to a specific method, a resistance welding method, as in this embodiment, is preferred. This is because applying pressure using a welding rod WR allows the tab 43 and the positive electrode terminal 31 to be welded together while compressing the first cushion member 41. Another possible welding method is ultrasonic welding. However, ultrasonic welding requires the anvil and horn to be clamped and oscillated, which is unsuitable for this embodiment because it is difficult to insert the anvil into the clearance SP. Another possible welding method is projection welding. However, this method requires the tab to have a gap between the welded portions to allow reactive current to flow, which increases the risk of moisture intrusion through this gap after welding. Therefore, the objective of waterproofing the area around the battery terminal cannot be achieved, and therefore projection welding is unsuitable. Therefore, resistance welding is preferred as a welding method.

[0059] The welding rod WR has two protrusions corresponding to the positive and negative polarities. For example, two resistance welds are performed on one welding point. As a result, as shown schematically in FIG. 16, two pairs of resistance weld marks 71 are formed on one welding point. Deformation of the tab 43 during welding generates stress concentrically around the welding point (the location of the resistance weld mark 71). In FIG. 16, the location where stress occurs is shown schematically by an "x". As a result, the first cushion member 41 is firmly attached to the top and bottom in a compressed state, preventing moisture from entering the positive terminal 31.

[0060] A specific welding method will be described with reference to Figures 17A and 17B. Figures 17A and 17B show an example of welding a predetermined location of tab 43B to negative electrode terminal 32 of lithium ion battery 1D. Note that in Figures 17A and 17B, the configuration near negative electrode terminal 32 is appropriately simplified.

[0061] For example, the above-described integrated first cushion member 41 and first tab sheet assembly 42 are placed against the peripheral edge of the end face where the terminal portion (negative terminal 32 in this example) of the lithium ion battery 1D is formed. As a result, the first cushion member 41, insulating film 45, tab 43, and insulating film 44 are placed in this order against the peripheral edge (peripheral edge 32A) of the end face where the negative terminal 32 of the lithium ion battery 1D is formed. When the terminal portion is the negative terminal 32, the peripheral edge 32A of the end face is, for example, a flat area where insulating tape is attached to the exterior of the lithium ion battery 1D.

[0062] When the integrated first cushion member 41 and first tab sheet assembly 42 are positioned, the tab 43 (specifically, tab 43B) and the negative electrode terminal 32 of the lithium ion battery 1D face each other with a clearance SP between them, as shown in FIG. 17A.

[0063] Next, a welding rod WR is brought into contact with a portion of the tab 43B opposite the side facing the negative electrode terminal 32 and pressed in, thereby deforming the tab 43B. The stress caused by pressing the welding rod WR is transmitted to the first cushion member 41, compressing the first cushion member 41. By pressing the welding rod WR while compressing the first cushion member 41, a portion of the tab 43B comes into contact with the negative electrode terminal 32. By passing a current through the welding rod WR in this contact state, a portion of the tab 43B and the negative electrode terminal 32 are welded together, as shown in FIG. 17B . In the welded state, the first cushion member 41 is positioned between the peripheral edge 32A of the end face where the negative electrode terminal 32 is formed and the tab 43, so as to surround the negative electrode terminal 32. Furthermore, the first cushion member 41 is sandwiched between the peripheral edge 32A and the tab 43. Specifically, the opening periphery of hole 411D of first cushion member 41 is compressed and held between periphery 32A and tab 43. Resistance welding marks 71 are formed on upper surface 433A of tab 43B.

[0064] Although not shown, other welding locations are performed in the same manner. The process of manufacturing the second tab sheet assembly 52 and the process of welding the tabs 53 are performed in the same manner. In this manner, the battery unit 2 is completed.

[0065] [Numerical examples] Next, specific examples of the numerical values ​​of the battery unit 2 will be described. First, specific examples of the size of the clearance will be described. The length of the clearance (length in the Z-axis direction) is defined as shown in FIG. 18. The length from the part on the bottom surface of the tab 43 that is not connected to the terminal portion (positive terminal 31 in the illustrated example) to the positive terminal 31 is defined as the length of the clearance. Note that FIG. 18 shows the state before welding, but after welding, the following lengths are defined based on the parts that have not been deformed by welding.

[0066] Specifically, an arbitrary reference position, for example, the length of the bottom surface from the bottom of the battery can 11 to the crimped portion 11P is defined as h0, the height of the lithium ion battery 1 is defined as h1, and the height to the bottom surface (welding surface) of the tab 43 is defined as h2. Note that the reference position may be the center of the battery can 11 instead of the bottom.

[0067] Incidentally, evaluation is performed using the IP rating of the IEC standard as an index of waterproofness (waterstopping). The last digit of the IP rating corresponds to the waterproofness index. In this embodiment, as shown in FIG. 19 , a clearance of 0.3 mm or more provides waterproofness of IPX5 or higher, and a clearance of 1.0 mm or more provides waterproofness of IPX8 or higher. The waterproof level required for battery units used outdoors is IPX5 to IPX8. Therefore, the clearance length is preferably 0.3 mm or more. On the other hand, if the clearance is 2.0 mm or more, the cushion member cannot be compressed sufficiently by the pressure applied during resistance welding, making it impossible to bring the welding surface into contact with the terminal portion, i.e., welding is impossible. Therefore, the clearance length is preferably 0.3 mm or more but less than 2.0 mm. Furthermore, if the clearance length is 1.0 mm or more, welding is possible, but there is a high risk of welding defects. Therefore, the clearance length is more preferably 0.3 mm or more but less than 1.0 mm.

[0068] A specific numerical example is shown below. Insulation film thickness = 0.05 to 0.10 mm Tab thickness = 0.15~0.20mm Cushion material thickness = 0.50 to 1.50 mm h0=64.90mm h1=65.00mm h2 can be expressed as "h0 + thickness of cushion material + thickness of insulating film", so Minimum value of h2 = 64.90 + 0.50 + 0.05 = 65.45 mm Maximum value of h2 = 64.90 + 1.50 + 0.10 = 66.50 mm The maximum value of the clearance length can be expressed as the difference between the maximum value of h2 and h1. The minimum value of the clearance length can be expressed as the difference between the minimum value of h2 and h1. Minimum clearance length = 65.45 - 65.00 = 0.45 mm Maximum clearance length = 66.50 - 65.00 = 1.50 mm This becomes:

[0069] Next, an example of the size of the cushion member will be described. As shown in Fig. 20, L2, which is half the outer diameter of the lithium-ion battery 1, is set to be larger than the length L1 from the center line CL of the lithium-ion battery 1 to the end face of the hole in the cushion member (for example, the first cushion member 41), and is set so that an overlap occurs between the cushion member and the battery can. Without such an overlap, the cushion member would not be able to achieve its waterproof function due to compression.

[0070] Specific numerical examples are shown below. Half the outer diameter of lithium-ion battery 1 (L2) = φ18 / 2 = 9.00 mm Cushion material hole diameter φ1 = 10.00 mm Center line of lithium ion battery 1 CL~L1 = 9.00-10.00 / 2 = 4.00 mm Overlap amount = L2 - L1 = 9.00 - 4.00 = 5.00 mm

[0071] In the battery unit according to the present embodiment described above, the cushion member is compressed when the tabs are welded and is positioned to surround the periphery (360°) of the terminals, effectively preventing moisture and other substances from entering the periphery of the terminals and improving the waterproofing of the battery unit. Furthermore, by using a foam having a closed cell structure or a foam having a semi-closed cell structure for the cushion member, it is possible to prevent moisture from permeating, thereby preventing the occurrence of migration. Furthermore, since the tab has no opening, it is possible to prevent moisture from entering the periphery of the terminal portion through an opening provided in the tab as in the conventional case. Furthermore, since there is no need to arrange a waterproofing member for each individual lithium ion battery, there is no risk of the waterproofing member being misaligned, and the number of assembly steps can be reduced.

[0072] <Modification> Although the embodiment of the present invention has been specifically described above, the content of the present invention is not limited to the above-described embodiment, and various modifications based on the technical concept of the present invention are possible. Several modifications will be described below. Note that the same reference numerals will be used to designate the same components as in the first embodiment, and redundant description will be omitted as appropriate.

[0073] [Variation 1] The battery unit 2 may have a battery holder that insulates, houses, and holds the lithium-ion batteries 1. Fig. 21 shows a battery holder (battery holder 81) according to Modification 1. The battery holder 81 has holes 81A to 81I that house nine lithium-ion batteries 1. For example, hole 81A houses and holds the lithium-ion battery 1A near the center of its body. The other holes similarly house and hold the corresponding lithium-ion batteries near the center of their body.

[0074] The battery holder 81 also has three pins 82A, 82B, and 82C. Pins 82A and 82B extend vertically relative to the surface on which the hole of the battery holder 81 is formed. Pin 82C extends downward relative to the surface on which the hole of the battery holder 81 is formed.

[0075] As shown in FIG. 22, the integrated body made up of the first cushion member 41 and the first tab sheet assembly 42 has holes 83A and 83B that penetrate vertically. As shown in FIG. 23, the upper end of pin 82A is inserted through hole 83A, and the upper end of pin 82B is inserted through hole 83B. Furthermore, the integrated body made up of the second cushion member 51 and the second tab sheet assembly 52 has three holes. As shown in FIGS. 22 and 23, the lower ends of pin 82A, pin 82B, and pin 82C are inserted through the corresponding holes. In this way, in the battery unit according to the modified example, the pins of the battery holder 81 penetrate through the holes.

[0076] This configuration makes it possible to easily position the integrated body consisting of the first cushion member 41 and the first tab sheet assembly 42. It also makes it possible to easily position the integrated body consisting of the second cushion member 51 and the second tab sheet assembly 52. ​​Since positioning can be easily performed, the welding position becomes accurate, enabling highly reliable welding.

[0077] The number of pins, their positions, and their shapes can be changed as appropriate. The positions and shapes of the holes through which the pins pass can also be changed as appropriate. However, it is preferable that the holes through which the pins pass are formed in a location where the cushion member and two insulating films are continuously laminated, in other words, in a location where no tab is interposed between the insulating films. This is because forming holes in the tabs reduces the area through which current flows.

[0078] [Variation 2] Next, another example of the battery holder will be described. In this modification, the shape of the tab 43B has been partially modified for ease of explanation. FIG. 24 shows a battery holder (battery holder 85) according to modification 2. The battery holder 85 has nine holes 85A to 85I corresponding to the number of lithium-ion batteries 1. The battery holder 85 also has pins 86A and 86B that extend upward relative to the surface on which the holes 85A and other holes are formed, and a pin 86C that extends downward relative to the surface on which the holes 85A and other holes are formed. The battery holder 85 also has a rib 86D that extends upward relative to the surface on which the holes 85A and other holes are formed, and a rib 86E that extends downward relative to the surface on which the holes 85A and other holes are formed. The ribs 86D and 86E separate areas of different potentials.

[0079] As shown in FIG. 25, holes 87A and 87B are formed in the integrated body made up of the first cushion member 41 and the first tab sheet assembly 42, penetrating in the vertical direction. As shown in FIG. 26, the pin 86A is inserted near its upper end into the hole 87A, and the pin 86B is inserted near its upper end into the hole 87B. Here, the tab 43A (an example of a first conductive member) is welded to the positive terminal 31 (positive potential, which is an example of a first potential), and a portion of the tab 43B (an example of a second conductive member) is welded to the negative terminal 32 (negative potential, which is an example of a second potential). In other words, the space between the tabs 43A and 43B corresponds to the space between the different potentials. Therefore, a through groove 87C is provided in the integrated body made up of the first cushion member 41 and the first tab sheet assembly 42 so that a rib 86D is disposed at that location (see FIG. 25). As shown in FIG. 26, a rib 86D is inserted into a through groove 87C, thereby isolating the areas with different potentials.

[0080] This configuration effectively prevents short circuits caused by contact between different potentials or contact of a metallic foreign object across different potentials during assembly of the battery unit, in addition to the effects obtained by Modification 1. Although not described in detail, the integrated body made up of second cushion member 51 and second tab sheet assembly 52 may also be provided with holes through which pin 86C passes and through grooves through which rib 86E passes.

[0081] [Variation 3] Modification 3 is an example in which first cushion member 41 has a thick portion. A thick portion refers to a portion that is relatively thicker than other portions. Such a thick portion is provided on the opening periphery of each hole portion provided in first cushion member 41. Specifically, in each of holes 411A to 41I, a thick portion is provided on the opening periphery on the side facing the periphery of the terminal portion of lithium ion battery 1 (for example, crimping portion 11P or periphery portion 32A).

[0082] Fig. 27A is a perspective view of first cushion member 41 according to this modified example as viewed from below, and Fig. 27B is a view showing Fig. 27A together with first tab sheet assembly 42. As shown in Figs. 27A and 27B, for example, thick portion 47A that is thicker than the surrounding area is provided on the opening periphery on the bottom side of hole 411A. Thick portions 47B to 47I are also provided on the opening periphery on the bottom side of the other holes, respectively.

[0083] By providing thick portions 47A-47I, as shown in Figures 28A and 28B, stress generated by welding can be concentrated locally. This allows first cushion member 41 to be highly compressed, further improving the sealing performance around the terminal portion. Note that thick portions may also be provided in the second cushion member in a similar manner. Note that the thick portions may be molded integrally with the cushion member, or may be formed separately and then integrated with the cushion member by adhesion or the like.

[0084] [Variation 4] Variation 4 is an example in which the tabs that make up the battery unit are provided with reinforcing parts that reinforce the periphery of the holes and through-grooves through which the pins and ribs pass.

[0085] 29A and 29B show a tab 91 according to this modification. The tab 91 includes a tab 91A and a tab 91B. The tab 91B includes, for example, two ring portions 91C and 91D. The ring portions 91C and 91D correspond to an example of a reinforcing portion. That is, in this modification, the tab and the reinforcing portion to be welded are integrally formed. A substantially circular space is formed inside each of the ring portions 91C and 91D.

[0086] As shown in FIGS. 30A and 30B , tab 91 is sandwiched between insulating films 44 and 45, similar to tab 43 (or tab 53). Insulating films 44 and 45 are provided with holes (e.g., holes 92A and 92B) through which the pins described in Modifications 1 and 2 pass. Holes 92A and 92B communicate with the spaces inside ring portions 91C and 91D. That is, ring portion 91C is disposed around hole 92A, and ring portion 91D is disposed around hole 92B. When a pin is to pass through a hole in a thin insulating film with low strength, the insulating film may wrinkle or tear, preventing the pin from passing smoothly. However, according to this modification, a reinforcing portion, which is part of a metal tab, is disposed around the hole. This allows the pin to pass smoothly through the hole without damaging the insulating film. The tab disposed below the battery unit may also have a reinforcing portion.

[0087] [Other variations] Other modified examples will be described. In the embodiment, a configuration in which the battery unit includes first and second insulating films has been described, but a configuration without a second insulating film is also possible. Also, in the embodiment, two tabs are arranged on the upper or lower side, but one tab, or three or more tabs may be arranged. The size of the lithium ion battery may be 21700 (diameter 21 mm, height 70 mm), 18650 (diameter 18 mm, height 65 mm), or other sizes. The number and connection mode of the lithium ion batteries that make up the battery unit can be changed as appropriate.

[0088] The matters described in the above-mentioned embodiments and modifications can be combined as appropriate. Furthermore, the materials, processes, etc. described in the embodiments are merely examples, and the contents of the present invention are not limited to the exemplified materials, etc.

[0089] <Application example> The battery unit according to the present invention can be mounted on or used to supply power to electronic devices, power tools, electric vehicles, various electronic devices, and the like.

[0090] (electronic equipment) A specific application example will be described. For example, the battery unit described above can be used as a power source for a wearable device having the functionality of a personal digital assistant, a so-called wearable terminal. Examples of wearable terminals include, but are not limited to, wristwatch-type terminals and eyeglass-type terminals.

[0091] FIG. 31 shows an example of a wearable terminal incorporating a miniaturized battery unit. As shown in FIG. 31, the wearable terminal 300 according to this application example is a wristwatch-type terminal that has a battery pack 302 inside. The battery unit according to the present invention can be applied as part of the battery pack 302. The wearable terminal 300 can be worn by a user and used. The wearable terminal 300 may be flexible and deformable.

[0092] 32 , a wearable terminal 300 according to the application example includes an electronic circuit 301 of an electronic device main body and a battery pack 302. The battery pack 302 is electrically connected to the electronic circuit 301. The wearable terminal 300 has a configuration that allows the user to freely attach and detach the battery pack 302. Note that the configuration of the wearable terminal 300 is not limited to this, and the battery pack 302 may be built into the wearable terminal 300 so that the user cannot detach the battery pack 302 from the wearable terminal 300.

[0093] When charging the battery pack 302, the positive terminal 304A and the negative terminal 304B of the battery pack 302 are connected to the positive terminal and the negative terminal of a charger (not shown), respectively. On the other hand, when discharging the battery pack 302 (when using the wearable terminal 300), the positive terminal 304A and the negative terminal 304B of the battery pack 302 are connected to the positive terminal and the negative terminal of the electronic circuit 301, respectively.

[0094] The electronic circuit 301 includes, for example, a CPU, a peripheral logic unit, an interface unit, a storage unit, and the like, and controls the entire wearable terminal 300.

[0095] The battery pack 302 includes a battery unit 310 (for example, a battery unit in one embodiment) and a charge / discharge circuit 303. The charge / discharge circuit 303 is mounted on a circuit board.

[0096] In this application example, an example in which the present invention is applied to the battery pack 302 is shown, but the battery unit according to the present invention may also be mounted on the electronic circuit 301 of the terminal main body.

[0097] (power tools) Referring to Figure 33, an example of an electric screwdriver as a power tool to which the present invention can be applied will be described in brief. An electric screwdriver 431 is provided with a motor 433 that transmits rotational power to a shaft 434, and a trigger switch 432 that is operated by the user. A battery pack 430 and a motor control unit 435 are housed in a housing below the handle of the electric screwdriver 431. The battery pack 430 is either built into the electric screwdriver 431 or is detachable. The battery unit described above can be applied to the battery pack 430.

[0098] The battery pack 430 and the motor control unit 435 may each be provided with a microcomputer (not shown) so that they can communicate with each other regarding charging and discharging information of the battery pack 430. The motor control unit 435 controls the operation of the motor 433 and can cut off the power supply to the motor 433 in the event of an abnormality such as over-discharge.

[0099] (Electric vehicle energy storage system) As an example of applying the present invention to a power storage system for an electrically powered vehicle, a configuration example of a hybrid vehicle (HV) employing a series hybrid system is shown schematically in Figure 34. A series hybrid system is a vehicle that runs on an electric power driving force conversion device using electric power generated by a generator powered by an engine, or electric power that is temporarily stored in a battery.

[0100] This hybrid vehicle 600 is equipped with an engine 601, a generator 602, an electric power driving force conversion device (a DC motor or an AC motor, hereinafter simply referred to as "motor 603"), driving wheels 604a, 604b, wheels 605a, 605b, a battery 608, a vehicle control device 609, various sensors 610, and a charging port 611. The battery unit of the present invention can be used as battery 608.

[0101] The motor 603 is operated by power from the battery 608, and the rotational force of the motor 603 is transmitted to the drive wheels 604a and 604b. The rotational force produced by the engine 601 can be used to generate power in the generator 602, which can be stored in the battery 608. Various sensors 610 control the engine speed via the vehicle control device 609 and the opening of a throttle valve (not shown).

[0102] When hybrid vehicle 600 is decelerated by a braking mechanism (not shown), the resistance force generated during deceleration is applied to motor 603 as a rotational force, and regenerative power generated by this rotational force is stored in battery 608. Battery 608 can be charged by connecting to an external power source via charging port 611 of hybrid vehicle 600. Such an HV vehicle is called a plug-in hybrid vehicle (PHV or PHEV).

[0103] The battery unit according to the present invention can be applied to a miniaturized primary battery and used as a power source for a tire pressure monitoring system (TPMS) built into the wheels 604 and 605 .

[0104] While the above description has been given using a series hybrid vehicle as an example, the present invention can also be applied to a parallel hybrid vehicle that uses both an engine and a motor, or a hybrid vehicle that combines a series and parallel hybrid system.Furthermore, the present invention can also be applied to electric vehicles (EVs or BEVs) that run solely on a drive motor without an engine, and fuel cell vehicles (FCVs). [Explanation of symbols]

[0105] 1. Lithium-ion battery 2. Battery unit 11P... Crimping part 31 Positive terminal 32...Negative terminal 32A...periphery 41 First cushion member 43, 53... Tab 44, 45, 54, 55... Insulating film 47A~47I...Thick part 51 Second cushion member 81, 85 Battery holder 82A, 82B, 82C pins 91C, 91D...Ring section

Claims

1. a battery having end faces at both ends and terminal portions formed on the end faces; a conductive member electrically connected to the terminal portion and having a first main surface and a second main surface; a first insulating film disposed on at least the first main surface side of the conductive member; a second insulating film disposed on at least the second main surface side of the conductive member; Equipped with the first insulating film and the second insulating film are heat-sealed together, the first insulating film has a first opening; the second insulating film has a second opening at a position facing at least the first opening, the conductive member is exposed through the first opening and the second opening, the terminal portion is formed on the conductive member, and a cushion member is disposed between the conductive member and a peripheral edge of the end surface on which the terminal portion is formed, so as to surround the terminal portion; The cushion member is attached to the second insulating film. Battery unit.

2. one of the terminal portions is a positive electrode terminal that is convex with respect to the end face on which the terminal portion is formed, The peripheral edge of the end face where the terminal portion is formed is a crimped portion formed by crimping the exterior of the battery. The battery unit according to claim 1 .

3. The cushion member is a waterproof foam. The battery unit according to claim 1 or 2.

4. The foam is a closed-cell foam or a semi-closed-cell foam. The battery unit according to claim 3 .

5. The conductive member is bent toward the terminal portion. The battery unit according to claim 1 .

6. The cushion member is sandwiched between the peripheral edge of the end face and the conductive member. The battery unit according to claim 5 .

7. The opening periphery of the cushion member is pinched so as to be compressed. The battery unit according to claim 6 .

8. The length from a portion of the second main surface of the conductive member that is not connected to the terminal portion to the terminal portion is within a range of 0.3 mm to 1.0 mm. The battery unit according to claim 1 .

9. Resistance welding marks are formed on the first main surface of the conductive member. The battery unit according to claim 1 .

10. Further, a battery holder for fixing the battery is provided, The battery holder includes a pin that penetrates the portion where the first insulating film and the cushion member are continuously laminated. The battery unit according to claim 1 .

11. a reinforcing portion is formed around the hole through which the pin passes, The reinforcing portion is formed from a part of the conductive member. The battery unit according to claim 10.

12. the conductive member includes a first conductive member connected to a terminal portion at a first potential and a second conductive member connected to a terminal portion at a second potential different from the first potential; The battery holder includes a rib that separates the first conductive member from the second conductive member. The battery unit according to claim 10.

13. A thick portion is formed on the opening periphery of the cushion member on the side opposite to the periphery. The battery unit according to claim 1 .

14. A method for manufacturing a battery unit including batteries each having an end surface at each end and a terminal portion formed on each of the end surfaces, the method comprising: a first insulating film having a first opening is disposed on at least the first main surface side of a conductive member having a first main surface and a second main surface, a second insulating film having a second opening is disposed on at least the second main surface side of the conductive member, and the first insulating film and the second insulating film are heat-sealed together such that the first opening and the second opening face each other and the conductive member is exposed through the first opening and the second opening; a cushion member is attached to the second insulating film between the conductive member and a peripheral edge of the end face on which the terminal portion of the battery is formed, so as to surround the terminal portion; The conductive member and the terminal portion are arranged to face each other with a clearance therebetween, The cushion member is compressed while pressing a welding rod against a portion of the conductive member opposite to the side facing the terminal portion, and a current is passed through the welding rod to weld the conductive member and the terminal portion. A method for manufacturing a battery unit.

15. An electronic device comprising the battery unit according to claim 1.

16. A power tool comprising the battery unit according to claim 1.

17. An electric vehicle comprising the battery unit according to claim 1.

Images