Power storage device

Abstract

To provide a power storage device with high reliability in sealing property.SOLUTION: A power storage device 100 disclosed herein includes an electrode body 20a that includes a first electrode, a case 10 that accommodates this, and a first current collector member 70 that is electrically connected to the first electrode. The case 10 includes a first wall 14 having a first penetration hole 18. The first current collector member 70 includes a first region 71 disposed along an inner surface 14b of the first wall 14. The first region 71 includes a protrusion part 72 protruding toward the first wall 14. At least a part of the protrusion part 72 is disposed in the first penetration hole 18. To the protrusion part 72, a terminal member 30 is connected. An insulating member 80 is a unified object including an insulating part disposed between the first wall 14 and the first current collector member 70, and an insulating part disposed between the first wall 14 and the terminal member 30.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses a technology related to a sealed battery. The sealed battery includes a current collecting terminal having an electrode assembly connection portion, an external connection portion, and a shaft portion located between the electrode assembly connection portion and the external connection portion. The electrode assembly connection portion is connected to an electrode assembly housed inside a case member. The external connection portion is located outside the case member. The shaft portion is inserted into a terminal mounting hole provided in the case member. An insulating member is also located between the current collecting terminal and the terminal mounting hole. The insulating member is integrally molded with the current collecting terminal and the case member. This is said to enable the electrode to be easily removed from the case member without undergoing a process such as joining multiple terminals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-086813 Summary of the Invention [Problem to be solved by the invention]

[0004] When the shape of a part is complex, the number of processing steps increases, which tends to cause variations in the shape of the manufactured part and may reduce the reliability of the sealing part. Therefore, the present inventors are considering making the shape of the part that constitutes the conduction path from the electrode body housed inside the case of an electricity storage device (e.g., a battery) relatively simple. [Means for solving the problem]

[0005] The present disclosure provides an electricity storage device comprising: an electrode assembly including a first electrode and a second electrode; a case that houses the electrode assembly; a first current collecting member electrically connected to the first electrode; and an insulating member that insulates the first current collecting member and the terminal member from the case. The case has a first wall, and the first wall has a first through hole. The first current collecting member has a first region arranged along the inner surface of the first wall, and the first region is provided with a protrusion that protrudes toward the first wall, and at least a portion of the protrusion is arranged within the first through hole. The terminal member is connected to the protrusion. The insulating member is an integral member having an insulating portion arranged between the first wall and the first current collecting member and an insulating portion arranged between the first wall and the terminal member.

[0006] With this configuration, a conductive path is formed by a simple configuration in which the protrusion of the first current collecting member is connected to the terminal member, and the insulating member is arranged as a single unit to insulate the terminal member and the first current collecting member from the case, thereby improving airtightness and increasing the reliability of the seal. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view schematically illustrating a configuration of an electricity storage device according to an embodiment. [Figure 2] 1 is a vertical cross-sectional view schematically illustrating a configuration of an electricity storage device according to an embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 2 is a perspective view schematically showing an electrode assembly attached to a sealing plate. [Figure 6] FIG. 2 is a perspective view schematically showing an electrode assembly to which a positive electrode second current collecting portion and a negative electrode second current collecting portion are attached. [Figure 7] FIG. 2 is a schematic diagram showing the configuration of an electrode body according to one embodiment. [Figure 8] FIG. 2 is a perspective view schematically illustrating the configuration of a first current collecting member according to one embodiment. [Figure 9] 3 is a perspective view schematically showing the configuration of the vicinity of a first through hole of a sealing plate to which a first current collecting member is attached according to one embodiment. FIG. [Figure 10] 10 is a perspective view of the configuration in the vicinity of the sealing plate to which the first current collecting member shown in FIG. 9 is attached, as viewed from the inner surface side of the sealing plate. [Figure 11] FIG. 10 is a cross-sectional view taken along line XI-XI in FIG. 9. [Figure 12] FIG. 10 is a cross-sectional view taken along line XII-XII in FIG. 9. [Figure 13] 12, showing a battery according to another embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, some preferred embodiments of the technology disclosed herein will be described with reference to the drawings. It should be noted that matters necessary for implementing the present disclosure other than those specifically mentioned in this specification (for example, the general configuration and manufacturing process of a battery that do not characterize the present disclosure) can be understood as design matters for a person skilled in the art based on the prior art in the relevant field. The present disclosure can be implemented based on the content disclosed in this specification and the common general technical knowledge in the relevant field. In this specification, the expression "A to B (where A and B are any numerical values)" indicating a range means "A or more and B or less," and also encompasses the meanings of "greater than A but less than B," "greater than A but B or less," and "greater than A but less than B."

[0009] In this specification, the term "power storage device" refers to a device that can be charged and discharged. Power storage devices include batteries such as primary batteries and secondary batteries (e.g., lithium ion secondary batteries and nickel-metal hydride batteries), and capacitors (physical batteries) such as electric double layer capacitors. Hereinafter, the present technology will be described using a lithium ion secondary battery, which is one embodiment of the power storage device disclosed herein, as an example.

[0010] FIG. 1 is a perspective view schematically illustrating the configuration of an electricity storage device 100 (hereinafter also referred to as battery 100). FIG. 2 is a longitudinal cross-sectional view schematically illustrating the configuration of battery 100. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom, and the symbols X, Y, and Z in the drawings represent the short side direction of battery 100, the long side direction perpendicular to the short side direction, and the up-down direction, respectively. However, these directions are merely used for convenience of description and do not limit the installation form of battery 100 in any way.

[0011] As shown in FIG. 2, the battery 100 according to this embodiment includes a case 10, an electrode assembly 20, a positive electrode terminal member 30, a negative electrode terminal member 40, a positive electrode current collector 50, a negative electrode current collector 60, and an insulating member 80. Although not shown, the battery 100 according to this embodiment further includes an electrolyte. The electrode assembly 20a of the electrode assembly 20 includes a first electrode and a second electrode. The first electrode can be a positive electrode or a negative electrode, but in this embodiment, the first electrode is a positive electrode. The second electrode is a positive electrode or a negative electrode, and is different from the first electrode. In this embodiment, the second electrode is a negative electrode.

[0012] Case 10 is a housing that houses one or more electrode bodies (here, electrode body group 20). Here, case 10 has a flat, bottomed, rectangular parallelepiped (rectangular) outer shape. The material of case 10 may be the same as that conventionally used, and is not particularly limited. Case 10 is preferably made of a metal having a predetermined strength, and may be made of, for example, aluminum, an aluminum alloy, iron, an iron alloy, or the like. The shape of case 10 is not limited to a rectangular shape, and may also be cylindrical or polyhedral.

[0013] Here, the case 10 has a hexahedral shape having six walls. As shown in FIG. 1 , the case 10 includes a first wall 14 as a top wall, a substantially rectangular bottom wall 12a facing the first wall 14, a pair of first side walls 12b extending upward in a U-direction from a short side of the bottom wall 12a and facing each other, and a pair of second side walls 12c extending upward in a U-direction from a long side of the bottom wall 12a and facing each other. The first wall 14 here is formed in a substantially rectangular shape. The area of ​​the second side wall 12c is smaller than the area of ​​the first side wall 12b. In this embodiment, the case 10 includes an exterior body 12 including the bottom wall 12a, the first side wall 12b, and the second side wall 12c, and a sealing plate (hereinafter also referred to as sealing plate 14) serving as the first wall 14. Note that the first wall is not limited to the sealing plate 14 and may be any of the walls included in the case 10.

[0014] The exterior body 12 is a flat, rectangular (hexahedral) container with an opening 12h on one side. The opening 12h is formed on the upper surface of the exterior body 12, which is surrounded by the pair of first side walls 12b and the pair of second side walls 12c. The sealing plate 14 is attached to the exterior body 12 so as to close the opening 12h of the exterior body 12. The sealing plate 14 is a plate material that is approximately rectangular in plan view. The case 10 is formed by joining (e.g., welding) the sealing plate 14 to the periphery of the opening 12h of the exterior body 12. The joining of the sealing plate 14 can be performed by welding, for example, laser welding.

[0015] 1 and 2, sealing plate 14 is provided with gas exhaust valve 17. Gas exhaust valve 17 is configured to open and exhaust gas from case 10 when the pressure inside case 10 reaches or exceeds a predetermined value.

[0016] In addition to the gas release valve 17, the sealing plate 14 is also provided with a liquid inlet 15, a first through-hole 18, and a second through-hole 19. The liquid inlet 15 is in communication with the internal space of the case 10 and is an opening provided for injecting electrolyte during the manufacturing process of the battery 100. The liquid inlet 15 is sealed with a sealing member 16. A suitable example of such a sealing member 16 is a blind rivet. This allows the sealing member 16 to be firmly fixed inside the case 10.

[0017] The first through hole 18 has a size that allows a portion of the positive electrode terminal member 30 or the positive electrode current collector 50 to be inserted therethrough, and its shape is not particularly limited. For example, in a plan view, the first through hole 18 may have a circular shape, an elliptical shape, a quadrate shape such as a square or a rectangle, or a polygonal shape. The corners of the first through hole 18 may be rounded. Here, the first through hole 18 is provided so that, in a plan view, the corners are rounded and the hole is rectangular. The shape of the second through hole 19 is not particularly limited as long as it has a size that allows a portion of the negative electrode terminal member 40 or the negative electrode current collector 60 to be inserted therethrough. The shape of the second through hole 19 may be the same as that of the first through hole 18.

[0018] FIG. 5 is a perspective view schematically illustrating the electrode assembly 20 attached to the sealing plate 14. In this embodiment, a plurality of (here, three) electrode assemblies 20a, 20b, and 20c are housed inside the case 10. The number of electrode assemblies housed inside one case 10 is not particularly limited and may be one or two or more (plural). As shown in FIG. 2, a positive electrode current collector 50 is disposed on one side of each electrode assembly in the long side direction Y (the left side in FIG. 2), and a negative electrode current collector 60 is disposed on the other side of each electrode assembly in the long side direction Y (the right side in FIG. 2). The electrode assemblies 20a, 20b, and 20c are connected in parallel. However, the electrode assemblies 20a, 20b, and 20c may also be connected in series. The electrode assembly 20 is housed inside the case 10 while covered with an electrode assembly holder 29 made of a resin sheet.

[0019] Fig. 6 is a perspective view schematically showing the electrode body 20a to which the positive electrode second current collecting portion 52 and the negative electrode second current collecting portion 62 are attached. Fig. 7 is a schematic diagram showing the configuration of the electrode body 20a. Note that, although the electrode body 20a will be described in detail below as an example, the electrode bodies 20b and 20c can also have a similar configuration.

[0020] As shown in FIG. 7, the electrode assembly 20a has a positive electrode 22, a negative electrode 24, and a separator 26. Here, the electrode assembly 20a is a wound electrode assembly in which a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked with two strip-shaped separators 26 interposed therebetween, and wound around a winding axis WL. However, the structure of the electrode assembly does not limit the technology disclosed herein. For example, the electrode assembly may be a laminated electrode assembly in which multiple square-shaped (typically rectangular) positive electrodes and multiple square-shaped (typically rectangular) negative electrodes are stacked in an insulated state.

[0021] In this embodiment, the electrode body 20a has a flat shape. The electrode body 20a is disposed inside the exterior body 12 with the winding axis WL oriented approximately parallel to the long side direction Y. Specifically, as shown in Fig. 3, the electrode body 20a has a pair of curved portions (R portions) 20r that face the bottom wall 12a and the sealing plate 14 of the exterior body 12, and a flat portion 20f that connects the pair of curved portions 20r and faces the first side wall 12b of the exterior body 12. The flat portion 20f extends along the first side wall 12b.

[0022] As shown in FIG. 7, the positive electrode 22 includes a positive electrode current collector 22c and a positive electrode active material layer 22a fixed to at least one surface of the positive electrode current collector 22c. The positive electrode 22 may also include a positive electrode protective layer 22p. The positive electrode current collector 22c is strip-shaped in this example. The positive electrode current collector 22c is made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The positive electrode current collector 22c is, for example, a metal foil, and in this example, is aluminum foil.

[0023] A plurality of positive electrode tabs 22t are provided at one end of the positive electrode current collector 22c in the long side direction Y (the left end in FIG. 7). The plurality of positive electrode tabs 22t are provided at intervals (intermittently) along the longitudinal direction of the strip-shaped positive electrode 22. The plurality of positive electrode tabs 22t protrude outward beyond the separator 26 toward one side in the axial direction of the winding axis WL (the left side in FIG. 7). The positive electrode tabs 22t may be provided on the other side in the axial direction of the winding axis WL (the right side in FIG. 7), or may be provided on both sides in the axial direction of the winding axis WL. The positive electrode tabs 22t are part of the positive electrode current collector 22c and are made of metal foil (aluminum foil). However, the positive electrode tabs 22t may be a member separate from the positive electrode current collector 22c. In at least a part of the positive electrode tab 22t, the positive electrode active material layer 22a and the positive electrode protective layer 22p are not formed, and a region where the positive electrode current collector 22c is exposed is formed.

[0024] As shown in FIG. 4, the positive electrode tabs 22t are stacked at one axial end (the left end in FIG. 4) of the winding axis WL to form a positive electrode tab group 23. Each of the positive electrode tabs 22t is connected to the positive electrode current collector 50 in a bent state. This allows the size of the main body of the electrode body group 20 housed in the case 10 to be increased, thereby increasing the energy density of the battery 100. As shown in FIG. 2, the positive electrode tab group 23 is electrically connected to the positive electrode current collector 50. Here, the positive electrode tab group 23 is connected to a positive electrode second current collector 52 (described later) at a connection J (see FIG. 4). The size of the positive electrode tabs 22t (the length in the long side direction Y and the width perpendicular to the long side direction Y; see FIG. 7) can be appropriately adjusted, for example, by their formation positions, taking into account the state of connection to the positive electrode current collector 50. Here, the positive electrode tabs 22t are different in size from one another so that their outer ends are aligned when bent. The positive electrode tabs may have the same size. Although the positive electrode tabs 22t are trapezoidal, they may have other shapes (for example, rectangular).

[0025] As shown in FIG. 7, the positive electrode active material layer 22a is provided in a strip-like shape along the longitudinal direction of the strip-shaped positive electrode current collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (e.g., a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide) capable of reversibly absorbing and releasing charge carriers. When the total solid content of the positive electrode active material layer 22a is taken as 100 mass%, the positive electrode active material may account for approximately 80 mass% or more, typically 90 mass% or more, for example, 95 mass% or more. The positive electrode active material layer 22a may contain optional components other than the positive electrode active material, such as a conductive material, a binder, various additives, etc. Examples of the conductive material include a carbon material such as acetylene black (AB). Examples of the binder include polyvinylidene fluoride (PVdF).

[0026] As shown in FIG. 7, the positive electrode protective layer 22p is provided at the boundary between the positive electrode collector 22c and the positive electrode active material layer 22a in the long side direction Y. Here, the positive electrode protective layer 22p is provided at one end (the left end in FIG. 7) of the positive electrode collector 22c in the axial direction of the winding axis WL. However, the positive electrode protective layer 22p may be provided at both ends in the axial direction. The positive electrode protective layer 22p is provided in a strip shape along the positive electrode active material layer 22a. The positive electrode protective layer 22p contains an inorganic filler (e.g., alumina). When the entire solid content of the positive electrode protective layer 22p is taken as 100% by mass, the inorganic filler may account for approximately 50% by mass or more, typically 70% by mass or more, for example, 80% by mass or more. The positive electrode protective layer 22p may contain optional components other than the inorganic filler, such as a conductive material, a binder, and various additive components. The conductive material and binder may be the same as those exemplified as those that may be contained in the positive electrode active material layer 22a.

[0027] As shown in Fig. 7, the negative electrode 24 includes a negative electrode current collector 24c and a negative electrode active material layer 24a fixed to at least one surface of the negative electrode current collector 24c. The negative electrode current collector 24c is strip-shaped. The negative electrode current collector 24c is made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel. The negative electrode current collector 24c is, for example, a metal foil, and in this example, is copper foil.

[0028] A plurality of negative electrode tabs 24t are provided at one axial end (the right end in FIG. 7) of the winding axis WL of the negative electrode current collector 24c. The plurality of negative electrode tabs 24t are provided at intervals (intermittently) along the longitudinal direction of the strip-shaped negative electrode 24. Each of the plurality of negative electrode tabs 24t protrudes outward from the separator 26 toward one axial end (the right end in FIG. 7). However, the negative electrode tab 24t may be provided at the other axial end (the left end in FIG. 7) or at each of both axial end portions. The negative electrode tab 24t is part of the negative electrode current collector 24c and is made of metal foil (copper foil). However, the negative electrode tab 24t may be a separate member from the negative electrode current collector 24c. At least a portion of the negative electrode tab 24t has a region where the negative electrode active material layer 24a is not formed and the negative electrode current collector 24c is exposed.

[0029] As shown in FIG. 4, the multiple negative electrode tabs 24t are stacked at one axial end (the right end in FIG. 4) to form a negative electrode tab group 25. The negative electrode tab group 25 is preferably provided at a position symmetrical to the positive electrode tab group 23 in the axial direction. Each of the multiple negative electrode tabs 24t is connected to the negative electrode current collector 60 in a bent state. This allows the size of the main body of the electrode body group 20 housed in the case 10 to be increased, thereby increasing the energy density of the battery 100. As shown in FIG. 2, the negative electrode tab group 25 is electrically connected to the negative electrode current collector 60. Here, the negative electrode tab group 25 and a negative electrode second current collector 62, which will be described later, are connected at a connection J (see FIG. 4). Like the multiple positive electrode tabs 22t, the multiple negative electrode tabs 24t are different in size so that their outer edges are aligned when bent. Note that the technology disclosed herein can also be applied to cases where the negative electrode tabs are the same size. Furthermore, although the negative electrode tab 24t is trapezoidal, it may have other shapes (for example, rectangular).

[0030] As shown in FIG. 7, the negative electrode active material layer 24a is provided in a strip-like shape along the longitudinal direction of a strip-shaped negative electrode current collector 24c. The negative electrode active material layer 24a contains a negative electrode active material (e.g., a carbon material such as graphite) that can reversibly store and release charge carriers. When the total solid content of the negative electrode active material layer 24a is taken as 100 mass%, the negative electrode active material may account for approximately 80 mass% or more, typically 90 mass% or more, for example 95 mass% or more. The negative electrode active material layer 24a may contain optional components other than the negative electrode active material, such as a binder, a dispersant, and various additives. Examples of the binder that can be used include rubbers such as styrene butadiene rubber (SBR). Examples of the dispersant that can be used include celluloses such as carboxymethyl cellulose (CMC).

[0031] As shown in FIG. 7, the separator 26 is a member that insulates the positive electrode active material layer 22a of the positive electrode 22 from the negative electrode active material layer 24a of the negative electrode 24. A suitable example of the separator 26 is a porous resin sheet made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP). The separator 26 may have a substrate made of a porous resin sheet and a heat resistance layer (HRL) containing an inorganic filler and provided on at least one surface of the substrate. Examples of inorganic fillers that can be used include alumina, boehmite, aluminum hydroxide, and titania.

[0032] The electrolyte may be the same as conventional ones and is not particularly limited. The electrolyte is, for example, a non-aqueous electrolyte 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 in a solid state (solid electrolyte) and integrated with the electrode assembly 20.

[0033] The positive electrode current collecting part 50 constitutes at least a part of the conduction path from the positive electrode tab group 23 consisting of the multiple positive electrode tabs 22t to the outside of the case 10. In this embodiment, as shown in Fig. 2, the positive electrode current collecting part 50 includes a positive electrode first current collecting part 51 and a positive electrode second current collecting part 52. Note that the positive electrode current collecting part 50 does not have to be composed of multiple members as in this embodiment, and may be composed of a single member.

[0034] In this embodiment, the first current collecting member 70 disclosed herein is used as the positive electrode first current collecting part 51. The configuration of the first current collecting member 70 will be described later.

[0035] The positive electrode second current collecting portion 52 extends along the second side wall 12c of the exterior body 12. In this embodiment, as shown in FIG. 6, the positive electrode second current collecting portion 52 is configured in a plate shape extending in the vertical direction Z. The positive electrode second current collecting portion 52 has an inclined portion midway along its extension in the vertical direction Z. One end of the positive electrode second current collecting portion is joined to the positive electrode first current collecting portion 51, and the other end is joined to the positive electrode tab group 23. These joints can be realized by welding, for example, ultrasonic welding, resistance welding, laser welding, or the like. The positive electrode second current collecting portion 52 can be made of, for example, the same metal type as the positive electrode current collector 22c, and can be made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel.

[0036] As shown in FIGS. 1 and 2, the positive electrode terminal member 30 is disposed such that at least a portion thereof is exposed to the outside of the case 10. The positive electrode terminal member 30 is electrically connected to the positive electrode current collector 50, thereby extending the conduction path and improving connectivity with an external member (e.g., a bus bar). In this embodiment, as shown in FIG. 2, the positive electrode terminal member 30 is electrically connected to the positive electrode first current collector 51 inside a first through-hole 18 provided in the sealing plate 14. An upper surface 30a of the positive electrode terminal member 30 is disposed outside the case 10 and can serve as a bonding surface with an external member. The positive electrode terminal member 30 is preferably made of metal, and may be formed of, for example, aluminum, an aluminum alloy, nickel, stainless steel, or the like.

[0037] The shape of the positive electrode terminal member 30 is not particularly limited, but may be, for example, a plate shape, a block shape, etc. Furthermore, the shape of the positive electrode terminal member 30 in a plan view is not particularly limited, but is preferably a circle, a rectangle, or a shape with rounded corners.

[0038] The negative electrode current collecting part 60 constitutes at least a part of the conduction path from the negative electrode tab group 25 consisting of the multiple negative electrode tabs 24t to the outside of the case 10. In this embodiment, as shown in FIG. 2 , the negative electrode current collecting part 60 includes a negative electrode first current collecting part 61 and a negative electrode second current collecting part 62. Note that the negative electrode current collecting part 60 does not have to be composed of multiple members as in this embodiment, and may be composed of a single member. In this embodiment, the first current collecting member 70 disclosed herein is used as the negative electrode first current collecting part 61.

[0039] The negative electrode second current collecting portion 62 extends along the second side wall 12c of the exterior body 12. In this embodiment, as shown in FIG. 6 , the negative electrode second current collecting portion 62 is configured in a plate shape extending in the vertical direction Z. The negative electrode second current collecting portion 62 has an inclined portion midway along its extension in the vertical direction Z. One end of the negative electrode second current collecting portion 62 is joined to the negative electrode first current collecting portion 61, and the other end is joined to the negative electrode tab group 25. These joints can be realized by welding, for example, ultrasonic welding, resistance welding, laser welding, or the like. The negative electrode second current collecting portion 62 can be made of, for example, the same metal type as the negative electrode current collector 24c, and can be made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel.

[0040] As shown in FIGS. 1 and 2, the negative electrode terminal member 40 is disposed so that at least a portion thereof is exposed to the outside of the case 10. The negative electrode terminal member 40 is electrically connected to the negative electrode current collector 60, thereby extending the conduction path and improving connectivity with an external member (e.g., a bus bar). In this embodiment, as shown in FIG. 2, the negative electrode terminal member 40 is electrically connected to the negative electrode first current collector 61 inside a second through-hole 19 provided in the sealing plate 14. The negative electrode terminal member 40 is preferably made of metal, and more preferably made of copper or a copper alloy, for example. The shape of the negative electrode terminal member 40 may be the same as that of the positive electrode terminal member 30 described above.

[0041] The first current collecting member 70 disclosed herein will be described below. The first current collecting member 70 is a member electrically connected to at least one of the first electrode and the second electrode. In the following description, details will be provided using an embodiment in which the first current collecting member 70 is electrically connected to a positive electrode serving as the first electrode. Note that the first current collecting member 70 can also be used as a negative electrode, and its structure can be understood by, for example, replacing the positive electrode with the negative electrode in the following description.

[0042] Fig. 8 is a perspective view schematically illustrating one embodiment of the configuration of a first current collecting member disclosed herein. Fig. 9 is a perspective view schematically illustrating the configuration in the vicinity of a first through hole in the vicinity of a sealing plate to which a first current collecting member is attached. Fig. 10 is a perspective view of the configuration in the vicinity of the first through hole of the sealing plate to which the first current collecting member shown in Fig. 9 is attached, as viewed from the inner surface side of the sealing plate. Fig. 11 is a cross-sectional view taken along line XI-XI in Fig. 9. Fig. 12 is a cross-sectional view taken along line XII-XII in Fig. 9.

[0043] 8, the first current collecting member 70 has a first region 71, a second region 73, and a first slit 74 formed between the first region 71 and the second region 73. In this embodiment, the first current collecting member 70 further has a third region 75, a second slit 76 formed between the first region 71 and the third region 75, a fourth region 77, and a fifth region 78.

[0044] The first region 71 is a region that is disposed along the inner surface 14b of the first wall (here, the sealing plate 14) of the case 10. An upper surface 71a of the first current collecting member 70 in the first region 71 faces the inner surface 14b of the sealing plate 14. Here, the first region 71 extends in the longitudinal direction (long side direction Y) of the sealing plate 14. The first region 71 is provided with a base portion 71c and a protruding portion 72 that protrudes from the base portion 71c. The protruding portion 72 protrudes toward the first wall (sealing plate 14). In this embodiment, the protruding portion 72 has an upper surface 72a (tip surface). The protruding portion 72 also has a lower surface 72b that faces the upper surface 72a. Note that the tip of the protruding portion 72 does not necessarily have an upper surface. In this embodiment, the base portions 71c are disposed on both sides of the protruding portion 72 in the long side direction Y.

[0045] In this embodiment, the first current collecting member 70 is formed in a plate shape in the first region 71. The protruding portion 72 is formed by bending the plate-shaped first current collecting member 70 so that it protrudes toward the upper surface 71a. Accordingly, a recess 71d corresponding to the shape of the protruding portion 72 is provided on the lower surface 71b of the first current collecting member 70 in the first region 71. The bottom surface of the recess 71d is the lower surface 72b of the protruding portion 72. Here, the plate-shaped first current collecting member 70 is bent to form the protruding portion 72, so the average thickness of the first current collecting member 70 on the upper surface 72a of the protruding portion 72 is substantially the same as the average thickness of the first current collecting member 70 on the base portion 71c. For example, when the average thickness of the first current collecting member 70 on the base portion 71c is 100%, the average thickness of the first current collecting member 70 on the upper surface 72a of the protruding portion 72 may be 90% to 110%, or 95% to 105%. In this way, forming the protruding portion 72 by bending the plate-like member is preferable because the protruding portion 72 is lighter than a structure in which the protruding portion 72 is a solid shaft, thereby reducing the weight of the battery 100. However, the configuration of the protruding portion 72 is not limited to this, and the protruding portion 72 may be configured as a solid shaft or a hollow shaft. The average thickness of the first current collecting member 70 can be measured using, for example, a reflective laser displacement meter.

[0046] The length of the first region 71 in the longitudinal direction (direction Y) of the sealing plate 14 is preferably greater than the longest length in the longitudinal direction of the first through hole 18. This allows the insulating members 80, which will be described later and are disposed between the first region 71 and the sealing plate 14, to be disposed on both sides of the first through hole 18 in the longitudinal direction, thereby improving the sealing performance in the vicinity of the first through hole 18.

[0047] Like the first region 71, the second region 73 is a region disposed along the inner surface 14b of the first wall (here, the sealing plate 14) of the case 10. The second region 73 is a region disposed to the side of the first region 71. In other words, the second region 73 is disposed at a position offset from the first region 71 (for example, at a position offset from the base portion 71c) in a plane parallel to the inner surface 14b of the first wall (sealing plate 14). Here, the second region 73 is disposed on one side of the first region 71 in the short-side direction X of the battery 100. The second region 73 may also be disposed on one side of the first region 71 in the long-side direction Y of the battery 100. Here, the second region 73 extends in the longitudinal direction (long-side direction Y) of the first wall (sealing plate 14). In this embodiment, the first current collecting member 70 in the second region 73 is configured in a plate shape. The second region 73 is not an essential component in the present technology.

[0048] The first slit 74 is formed between the first region 71 and the second region 73. In this embodiment, the first slit 74 is formed in a substantially rectangular shape in a plan view. Here, in a plan view, the substantially rectangular shape has a short side that is the distance between the first region 71 and the second region 73 and a long side that is perpendicular to the short side. By having the first slit 74 in the first current collecting member 70, the insulating member 80 (described later) can easily enter the first slit 74, and the sealing performance around the periphery of the first through hole 18 can be improved.

[0049] In this embodiment, the length of the first slit 74 in the longitudinal direction (direction Y) of the sealing plate 14 is longer than the longest length of the first through hole 18 in the longitudinal direction. Furthermore, the first slit 74 is arranged to span both ends of the first through hole 18 in the longitudinal direction. This can further improve the sealing performance around the periphery of the first through hole 18.

[0050] The third region 75 is a region disposed along the inner surface 14b of the first wall (here, the sealing plate 14) of the case 10. The third region 75 is a region disposed to the side of the first region 71. Here, the third region 75 is disposed on the opposite side of the second region 73 with respect to the first region 71. That is, the first region 71 is disposed between the second region 73 and the third region 75. Here, the third region 75 is disposed on one side of the first region 71 in the short-side direction X of the battery 100. The third region 75 may also be disposed on one side of the first region 71 in the long-side direction Y of the battery 100. Here, the third region 75 extends in the longitudinal direction (long-side direction Y) of the first wall (sealing plate 14). In this embodiment, the first current collecting member 70 in the third region 75 is configured in a plate shape. The third region 75 is not an essential component.

[0051] The second slit 76 is formed between the first region 71 and the third region 75. In this embodiment, the second slit 76 is formed in a rectangular shape in a plan view. Here, in a plan view, the second slit 76 has a rectangular shape with the short side being the distance between the first region 71 and the third region 75 and the long side being perpendicular to the short side. By having the second slit 76 in the first current collecting member 70, the insulating member 80 (described later) can easily enter the second slit 76, which can improve the sealing performance around the first through hole 18. By having the first slit 74 and the second slit 76 in the first current collecting member 70, the sealing performance at both ends of the first through hole 18 is improved, thereby realizing a battery 100 with higher sealing reliability. Note that the second slit 76 is not a required component.

[0052] In this embodiment, the length of the second slit 76 in the longitudinal direction (direction Y) of the sealing plate 14 is longer than the longest length of the first through hole 18 in the long side direction. Furthermore, the second slit 76 is arranged to span both ends of the first through hole 18 in the long side direction. This can further improve the sealing performance around the periphery of the first through hole 18.

[0053] As shown in FIG. 8 , in this embodiment, the fourth region 77 is a region extending in the up-down direction Z. The fourth region 77 is a region extending from the sealing plate 14 side toward the bottom wall 12a side of the case 10. The fourth region 77 is disposed, for example, along the first side wall 12b or the second side wall 12c of the case 10. In this embodiment, the fourth region 77 is disposed along the second side wall 12c. Here, the fourth region 77 is electrically connected to the positive electrode second current collecting portion 52. This provides electrical continuity to the first current collecting member 70. The fourth region 77 may be directly joined to the positive electrode tab group 23. This reduces the number of components in the electrical continuity path and may reduce costs. Such joining can be achieved by welding, such as ultrasonic welding, resistance welding, or laser welding. In this embodiment, the first current collecting member 70 in the fourth region 77 is formed in a plate shape. The fourth region 77 is not an essential component of the present technology.

[0054] The fifth region 78 is a region connecting the first region 71 and the fourth region 77. Here, as shown in FIG. 8 , the fifth region 78 is disposed between the first region 71 and the fourth region. The fifth region 78 is disposed contiguous to the first region 71. Here, the fifth region is disposed contiguous to the fourth region 77. In the present embodiment, the fifth region 78 is also located between the second region 73 and the fourth region 77 and is disposed contiguous to the second region 73. The fifth region 78 is also located between the third region 75 and the fourth region 77 and is disposed contiguous to the third region 75. The fifth region 78 is disposed along the inner surface 14b of the first wall (here, the sealing plate 14) of the case 10. In the fifth region 78, the first current collecting member 70 is formed in a plate shape. Note that the fifth region 78 is not an essential component in the present technology. For example, the fourth region 77 and the first region 71 may be connected. Furthermore, the second region 73 and / or the third region 75 may be connected to the fourth region 77.

[0055] The first current collecting member 70 may be made of, for example, a metal, such as aluminum, an aluminum alloy, copper, or a copper alloy.

[0056] It is preferable that the thickness of the first current collecting member 70 is approximately constant throughout. For example, when the average thickness of the first current collecting member 70 is taken as 100%, the maximum thickness of the first current collecting member 70 is preferably 120% or less, more preferably 110% or less, and even more preferably 105% or less. Furthermore, the minimum thickness of the first current collecting member 70 is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more.

[0057] The first current collecting member 70 can be easily manufactured by, for example, bending or punching a single plate-shaped material (e.g., a metal plate), thereby realizing a first current collecting member 70 with a substantially uniform thickness throughout.

[0058] At least a portion of the protrusion 72 of the first current collecting member 70 is disposed inside the first through hole 18 provided in the sealing plate 14 (see FIGS. 11 and 12 ). Here, an upper surface 72a, which is the upper end (tip) of the protrusion 72, is disposed inside the first through hole 18. In the present embodiment, the upper surface 72a of the protrusion 72 is connected to the lower surface 30b of the positive electrode terminal member 30 inside the first through hole 18. The method for connecting the positive electrode terminal member 30 and the first current collecting member 70 is not particularly limited, and examples thereof include crimping, ultrasonic bonding, resistance welding, laser welding, and pressure welding. One or a combination of these methods may be selected from these. In the present embodiment, the lower surface 72b of the protrusion 72 is disposed closer to the inside of the case 10 than the inside of the first through hole 18. However, the lower surface 72b of the protrusion 72 may also be disposed inside the first through hole 18.

[0059] 9 to 12, the insulating member 80 insulates the first current collecting member 70 from the case 10 (here, the sealing plate 14). Here, the insulating member 80 also insulates the positive electrode terminal member 30 from the case 10 (here, the sealing plate 14). In this embodiment, the insulating member 80 includes a first insulating portion 82 disposed inside the case 10, a second insulating portion 84 disposed inside the first through-hole 18, and a third insulating portion 86 disposed outside the case 10.

[0060] 10 to 12, the first insulating portion 82 is disposed along the inner surface 14b of the sealing plate 14. The first insulating portion 82 is disposed inside the case 10, between the region of the first current collecting member 70 that faces the sealing plate 14 and the inner surface 14b of the sealing plate 14. Here, the second region 73 of the first current collecting member 70 is disposed so as to face the inner surface 14b of the sealing plate 14 with the first insulating portion 82 interposed therebetween. Similarly, in this embodiment, the third region 75 and the fifth region 78 of the first current collecting member 70 are also disposed so as to face the inner surface 14b of the sealing plate 14 with the first insulating portion 82 interposed therebetween. Furthermore, the portion of the first region 71 of the first current collecting member 70 that is disposed inside the case 10 is disposed so as to face the inner surface 14b of the sealing plate 14 with the first insulating portion 82 interposed therebetween.

[0061] The first insulating portion 82 is preferably disposed without any gap between the region of the first current collecting member 70 facing the sealing plate 14 and the inner surface 14b of the sealing plate 14. This can further improve the sealing performance of the periphery of the first through hole 18.

[0062] It is preferable that at least a portion of the first insulating portion 82 is disposed inside the first slit 74 of the first current collecting member 70 (see FIG. 10 ). This brings the first current collecting member 70 and the first insulating portion 82 into closer contact, thereby improving the sealing performance in the vicinity of the first through hole 18. In this embodiment, the first insulating portion 82 is disposed inside the first slit 74 on the sealing plate 14 side, and the first insulating portion 82 is not disposed at the end of the first slit 74 on the electrode body group 20 side. This configuration is advantageous from the perspective of reducing the weight of the battery 100. However, the first insulating portion 82 may be disposed throughout the entire inside of the first slit 74. This configuration is advantageous from the perspective of improving the sealing performance.

[0063] It is preferable that at least a portion of the first insulating portion 82 is disposed inside the second slit 76 of the first current collecting member 70 (see FIG. 10 ). This allows for closer contact between the first current collecting member 70 and the first insulating portion 82, thereby improving the sealing performance in the vicinity of the first through-hole 18. In this embodiment, the first insulating portion 82 is disposed inside the second slit 76 on the sealing plate 14 side, and the first insulating portion 82 is not disposed at the end of the second slit 76 on the electrode body group 20 side. This configuration is advantageous from the perspective of reducing the weight of the battery 100. However, the first insulating portion 82 may be disposed throughout the entire inside of the second slit 76. This configuration is advantageous from the perspective of improving the sealing performance.

[0064] At least a portion of the first insulating portion 82 is preferably disposed on the electrode assembly group 20 side of the protruding portion 72 of the first current collecting member 70 (the side of the lower surface 72b of the protruding portion 72). Here, the protruding portion 72 and the first insulating portion 82 are disposed so as to abut against each other. This can improve the sealing performance in the vicinity of the first through-hole 18. Furthermore, the first insulating portion 82 is preferably bridged so as to pass through the electrode assembly group 20 side of the protruding portion 72. In this embodiment, the first insulating portion 82 bridges the electrode assembly group 20 side of the protruding portion 72 (the recess 71d) in two locations in the short direction of the sealing plate 14. This can improve the adhesion between the first current collecting member 70 and the insulating member 80 and improve the sealing performance. The number of bridges is not particularly limited and may be one or more than two.

[0065] It is preferable that the first insulating portion 82, which is arranged on the electrode assembly 20 side of the protruding portion 72, is not arranged on the lower surface 71b side of the base portion 71c of the first region 71. In other words, it is preferable that the lower surface 71b of the base portion 71c is exposed. This makes it possible to expand the space occupied by the electrode assembly 20 inside the case 10. Here, on the lower surface 71b of the first region 71, the first insulating portion 82 is arranged only in the recess 71d on the electrode assembly 20 side of the protruding portion 72.

[0066] The first insulating portion 82 may have a through hole 82a that penetrates from the electrode assembly group 20 side toward the underside of the protruding portion 72, at a position on the electrode assembly group 20 side of the protruding portion 72. As shown in Fig. 10 , when viewed from the inner surface 14b side of the sealing plate 14, the underside 72b of the protruding portion 72 is exposed in the through hole 82a. The through hole 82a can be formed, for example, in the manufacturing process described below.

[0067] In the second region 73, the first insulating portion 82 is preferably not arranged on the surface (lower surface) of the first current collecting member 70 facing the electrode assembly group 20, leaving the lower surface exposed. In addition, in the third region 75, the first insulating portion 82 is preferably not arranged on the surface (lower surface) of the first current collecting member 70 facing the electrode assembly group 20, leaving the lower surface exposed. This allows the space inside the case 10 that is occupied by the electrode assembly group 20 to be expanded.

[0068] The first insulating portion 82 is preferably disposed around the periphery of the first through hole 18. This can improve the sealing performance in the vicinity of the first through hole 18. The first insulating portion 82 is also preferably disposed around the periphery of the region of the first current collecting member 70 that faces the sealing plate 14. In this embodiment, the first insulating portion 82 is disposed so as to extend outward beyond the first region 71, the second region 73, and the third region 75 in the longitudinal direction (direction Y) of the sealing plate 14, and so as to extend outward beyond the fourth region 77. The first insulating portion 82 is also disposed so as to extend outward beyond the second region 73 and so as to extend outward beyond the third region 75 in the lateral direction (direction X) of the sealing plate 14. 11 and 12 , the thickness of the first insulating portion 82 around the area of ​​the first current collecting member 70 that faces the sealing plate 14 may be greater than the thickness of the first insulating portion 82 that is disposed between the first current collecting member 70 and the sealing plate 14. The first insulating portion 82 may be disposed so as to contact not only the surface of the first current collecting member 70 that faces the sealing plate 14 inside the case 10, but also the side surface of the first current collecting member 70 that extends in the thickness direction of the first current collecting member 70. This improves the adhesion between the first current collecting member 70 and the first insulating portion 82, and can further improve the sealing performance.

[0069] 2, the first insulating portion 82 may include a movement restricting portion 82b for restricting movement of the electrode assembly 20 toward the sealing plate 14. In FIG. 2, an end of the first insulating portion 82 protrudes toward the electrode assembly 20 as the movement restricting portion 82b.

[0070] The second insulating portion 84 is disposed between the inner surface 18a of the first through hole 18 and the first current collecting member 70 disposed inside the first through hole 18, and insulates the first current collecting member 70 from the sealing plate 14. Here, the second insulating portion is also disposed between the inner surface 18a of the first through hole 18 and the positive electrode terminal member 30 disposed inside the first through hole 18, and insulates the positive electrode terminal member 30 from the sealing plate 14.

[0071] The second insulating portion 84 is preferably disposed so as to block the first through hole 18. As shown in Figs. 11 and 12, in this embodiment, the first through hole 18 is blocked by the second insulating portion 84 and the upper end of the protruding portion 72. This improves sealing performance. Note that, when at least a portion of the recess 71d in the first region 71 of the first current collecting member 70 is disposed in the first through hole 18, the second insulating portion 84 may be disposed in this recess 71d.

[0072] The third insulating portion 86 is a portion that is continuous with the second insulating portion 84, and is disposed on the outside of the case 10. Here, the third insulating portion 86 is disposed outside the case 10 along the periphery of the positive electrode terminal member 30. In this embodiment, the upper surface of the insulating member 80 (outside the case 10) has a recess made up of the second insulating portion 84 and the third insulating portion 86, and at least a portion of the positive electrode terminal member 30 (here, the lower side of the positive electrode terminal member 30) is disposed in this recess. Note that the entire positive electrode terminal member 30 may also be disposed in this recess.

[0073] The third insulating portion 86 preferably contacts the surrounding area of ​​the first through hole 18 on the outer surface 14a of the sealing plate 14 (first wall). Here, in a plan view, the peripheral edge of the third insulating portion 86 is disposed outside the first through hole 18, and the peripheral edge contacts the outer surface 14a of the sealing plate 14. This can improve the sealing performance in the vicinity of the first through hole 18. Note that the insulating member 80 does not necessarily have to include the third insulating portion 86.

[0074] The insulating member 80 is made of, for example, a resin having electrical insulation properties. Examples of such resins include polyolefin resins such as polypropylene (PP), fluorinated resins such as perfluoroalkoxyethylene copolymer (PFA) and polytetrafluoroethylene (PTFE), and polyphenylene sulfide (PPS).

[0075] The insulating member 80 can be composed of multiple components, but is preferably an integrated part (integrally molded product) made of a single component. The insulating member 80 being an integrated part improves the airtightness between the first insulating portion 82 and the second insulating portion 84. In this embodiment, the insulating member 80 is an integrated part in which the first insulating portion 82, the second insulating portion 84, and the third insulating portion 86 are continuously provided, improving the sealing performance in the vicinity of the first through hole 18. That is, the insulating member 80 is disposed between the first region 71 and the sealing plate 14, passes through the first through hole 18, and contacts the surrounding area of ​​the first through hole 18 on the outer surface 14a of the sealing plate 14.

[0076] Furthermore, in the present technology, the insulating member 80, the sealing plate 14, and the first current collecting member 70 are preferably a single-piece molded product. In other words, the sealing plate 14 and the first current collecting member 70 are molded with the insulating member 80. This allows the insulating member 80 to adhere closely to the sealing plate 14 and the first current collecting member 70, improving the airtightness of the first through-hole 18 provided in the sealing plate 14 and the area around it. Note that in this embodiment, in addition to the sealing plate 14 and the first current collecting member 70, the positive electrode terminal member 30 is also molded with the insulating member 80, and the insulating member 80, the sealing plate 14, the first current collecting member 70, and the positive electrode terminal member 30 are a single-piece molded product.

[0077] The insulating member 80 can also be used on the negative electrode side in the same manner. In this case, it can be understood by appropriately replacing the positive electrode with the negative electrode in the above description.

[0078] 11 and 12 , a first surface-treated portion 92 may be provided on the inner surface 14b of the sealing plate 14 (first wall) near the periphery of the first through hole 18. The first surface-treated portion 92 is in contact with the insulating member 80. Providing the first surface-treated portion 92 may improve the airtightness and bonding strength between the inner surface 14b of the sealing plate 14 and the insulating member 80 near the first through hole 18, thereby improving the sealing performance near the first through hole 18. The first surface-treated portion 92 may be provided near at least a portion of the periphery of the first through hole 18, but is preferably provided along the entire periphery so as to surround the first through hole 18.

[0079] The first surface-treated portion 92 is preferably processed to have a high surface roughness (i.e., a roughened surface). The arithmetic mean roughness (Ra) of the first surface-treated portion 92 is preferably, for example, at least two times larger than the arithmetic mean roughness of the portion of the inner surface 14b of the sealing plate 14 (first wall) excluding the first surface-treated portion 92 (the portion not roughened), and may be at least three times larger, or even at least four times larger. The upper limit of this value is not particularly limited, but may be, for example, 10 times or less. The larger the arithmetic mean roughness, the more improved the adhesion between the first surface-treated portion 92 and the insulating member 80 due to the anchor effect. The arithmetic mean roughness in the present technology refers to a value measured using a stylus-type surface roughness measuring instrument based on JIS B0601:2001. The surface treatment method for the first surface treatment section 92 can be a known method, such as chemical etching, laser processing, or blast processing.

[0080] The first surface treatment section 92 may be subjected to a treatment for forming a chemical bond with a resin. A known method can be applied as the surface treatment method, and examples thereof include a silane coupling treatment.

[0081] As shown in FIGS. 11 and 12 , in this embodiment, the area of ​​the surface of the positive electrode terminal member 30 facing the first current collecting member 70 (the lower surface 30b of the positive electrode terminal member 30) is larger than the area of ​​the upper surface 72a of the protrusion 72 of the first current collecting member 70. This increases the contact area between the lower surface 30b of the positive electrode terminal member 30 and the insulating member 80, thereby improving the strength of the positive electrode terminal member 30. In this case, a second surface treatment portion 94 may be provided on at least a portion of the lower surface 30b of the positive electrode terminal member 30. The second surface treatment portion 94 is in contact with the insulating member 80. The second surface treatment portion 94 improves adhesion to the insulating member 80, thereby improving airtightness and adhesive strength.

[0082] The second surface-treated portion 94 is preferably processed to increase its surface roughness (i.e., to be a rough surface portion). The arithmetic mean roughness (Ra) of the second surface-treated portion 94 is preferably, for example, at least two times larger than the arithmetic mean roughness of the untreated portion of the positive terminal member 30 (e.g., the upper surface or side surface of the positive terminal member 30), and may be at least three times, or even at least four times larger. The upper limit of this value is not particularly limited, but may be, for example, 10 times or less. The larger the arithmetic mean roughness, the more improved the adhesion between the second surface-treated portion 94 and the insulating member 80 due to the anchor effect. The surface treatment method for the second surface-treated portion 94 can be a known method, such as chemical etching, laser processing, or blasting.

[0083] Treatment for forming a chemical bond with a resin may be performed on the second surface treatment portion 94. Known methods can be applied as the surface treatment method, and examples thereof include silane coupling treatment.

[0084] The battery 100 described above can be manufactured by a manufacturing method including, for example, a preparation step and a sealing step. Here, the preparation step includes an integral molding step. Note that the manufacturing method of the battery 100 is not limited to the manufacturing method described here.

[0085] In the preparation step, an outer casing 12, a sealing plate 14, a first current collecting member 70, and an electrode body 20a are prepared. The electrode body 20a may be an electrode body group 20. Here, a positive electrode terminal member 30, a negative electrode terminal member 40, a positive electrode second current collecting portion 52, and a negative electrode second current collecting portion 62 may also be prepared as necessary.

[0086] In the integral molding process, the sealing plate 14, the first current collecting member 70, and the insulating member 80 are integrally molded. In the above-described battery 100, the positive electrode terminal member 30 is also integrally molded. The integral molding process can be performed according to a conventionally known method, such as that described in JP 2021-086813 A. The integral molding process can be performed, for example, using a molding die, by a method including a part setting process, an upper die setting process, an injection molding process, and a part removal process.

[0087] In the component setting process, a molding die capable of realizing the desired structure of the insulating member 80 is prepared. The molding die includes, for example, an upper die and a lower die. The upper die has a gate portion for injecting molten resin for forming the insulating member 80. First, the first current collecting member 70 and the sealing plate 14 are placed in the lower die. It is preferable that the portion of the first current collecting member 70 where the insulating member 80 is not placed be in contact with the lower die. For example, it is preferable that the lower surface 71b of the first region 71 (base portion 71c) and the lower surface of the second region 73 be placed without any gaps with the lower die. In addition, it is preferable that the lower die has a support portion that contacts and supports the lower surface 72b of the protruding portion 72 of the first current collecting member 70. By supporting the protruding portion 72 with the support portion, pressure can be applied from the upper surface 72a of the protruding portion 72, thereby tightly adhering the lower surface of the first current collecting member 70 to the lower die. This prevents the molten resin of the insulating member 80 from penetrating the lower surface of the first current collecting member 70. The through-hole 82a of the first insulating portion 82 of the insulating member 80 may be a mark left by the placement of such a support portion. The sealing plate 14 is positioned so that at least a portion of the protruding portion 72 of the first current collecting member 70 is placed inside the first through-hole 18.

[0088] In the upper mold setting step, after the first current collecting member 70 and the sealing plate 14 are positioned, the upper mold is positioned on the outer surface 14a of the sealing plate 14. At this time, it is preferable that the upper mold be in contact with the outer surface 14a of the sealing plate 14 around the periphery of the portion where the third insulating portion 86 is formed, so that the molten resin does not flow onto the outer surface 14a of the sealing plate 14. It is also preferable that the upper mold be in contact with the upper surface 72a of the protruding portion 72. This prevents the insulating material from being placed on the upper surface 72a of the protruding portion 72. Furthermore, because both sides of the upper surface 72a of the protruding portion 72 can be sandwiched between the support portions of the lower mold and the upper mold, pressure can be applied to the protruding portion 72 stably.

[0089] In the injection molding process, molten resin, which is the resin that constitutes the insulating member 80, is injected from the gate portion of the upper mold. The injected molten resin is poured into the interior of the upper mold, passes through the first through-holes 18, and fills the interior of the lower mold. It is preferable that the molding die is preheated before the molten resin is filled. The heating temperature is not limited and can be, for example, 100°C to 200°C.

[0090] In the component removal process, first, the filled molten resin is cooled. This solidifies the molten resin, producing the insulating member 80. Then, the upper mold is separated from the lower mold, and an integrally molded product in which the sealing plate 14 and the first current collecting member 70 are molded with the insulating member 80 is removed. Thereafter, gate portions and molding burrs may be removed as necessary.

[0091] If the battery 100 includes a positive electrode terminal member 30, the first current collecting member 70 and the positive electrode terminal member 30 may be connected in advance and placed in the lower mold in the parts setting step. This allows the positive electrode terminal member 30, the first current collecting member 70, the sealing plate 14, and the insulating member 80 to be integrally molded. Furthermore, although the above description of the integral molding step has been given for the periphery of the first through hole 18, a similar step can also be performed for the second through hole 19.

[0092] In the sealing process, the prepared integrally molded product is first connected to the electrode assembly 20a. The integrally molded first current collecting member 70 is directly connected to the electrode tab of the electrode assembly 20a. Alternatively, the first current collecting member 70 may be connected to the electrode assembly 20a via the positive electrode second current collecting portion 52 or the negative electrode second current collecting portion 62. Next, the electrode assembly 20a is inserted through the opening 12h of the exterior body 12, and the integrally molded sealing plate 14 is joined to the periphery of the opening 12h of the exterior body 12 by laser welding or the like. An electrode assembly holder 29 may be interposed between the exterior body 12 and the electrode assembly 20a. Next, electrolyte is injected through the liquid inlet 15, which is then sealed with a sealing member to hermetically seal the case 10. In this manner, the battery 100 can be manufactured.

[0093] Battery 100 can be used for a variety of purposes, but can be suitably used, for example, as a power source (driving power source) for motors mounted on vehicles such as passenger cars and trucks. The type of vehicle is not particularly limited, and examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). Battery 100 can also be suitably used as a single cell that constitutes a battery pack.

[0094] Although several embodiments of the present technology have been described above, the above embodiments are merely examples. The present technology can be implemented in various other forms. The technology described in the claims includes various modifications and alterations of the above-exemplified embodiments. For example, it is possible to replace part of the above-described embodiments with other embodiments, and it is also possible to add other embodiments to the above-described embodiments. Furthermore, if a technical feature is not described as essential, it can also be deleted as appropriate.

[0095] FIG. 13 is a diagram corresponding to FIG. 12 of a battery 200 according to another embodiment. Here, a recess 30c is provided on the lower surface 30b of the positive terminal member 30. A protrusion 72c is provided on the upper surface 72a of the protrusion 72 of the first current collecting member 70. A recess 72d is provided on the lower surface 72b of the protrusion 72. The recess 72d is located behind the protrusion 72c and may be a structure formed when the plate-shaped first current collecting member 70 is deformed to provide the protrusion 72c. The recess 30c on the lower surface 30b of the positive terminal member 30 is fitted with the protrusion 72c on the upper surface 72a of the protrusion 72 of the first current collecting member 70. This facilitates positioning of the positive terminal member 30. Furthermore, the bonding strength between the positive terminal member 30 and the first current collecting member 70 can be improved. Note that other configurations may be similar to those of the battery 100.

[0096] Alternatively, a protrusion may be provided on the lower surface 30b of the positive terminal member 30 instead of the recess 30c, and a recess may be provided on the upper surface 72a of the protruding portion 72 of the first current collecting member 70 instead of the protrusion 72c, with the protrusion and recess mating with each other.

[0097] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Section 1: an electrode assembly including a first electrode and a second electrode; a case for accommodating the electrode assembly; a first current collecting member electrically connected to the first electrode; a terminal member connected to the first current collecting member; an insulating member that insulates the first current collecting member and the terminal member from the case; An electricity storage device comprising: the case having a first wall; the first wall has a first through hole; the first current collecting member has a first region disposed along an inner surface of the first wall; the first region is provided with a protruding portion that protrudes toward the first wall, At least a portion of the protrusion is disposed within the first through hole; The terminal member is connected to the protrusion, The insulating member is an integral part having an insulating portion disposed between the first wall and the first current collecting member, and an insulating portion disposed between the first wall and the terminal member. Item 2: The electricity storage device according to item 1, wherein the insulating member is disposed on the electrode body side of the protrusion. Item 3: The electricity storage device according to item 1 or 2, wherein an upper surface of the protrusion and the terminal member are connected inside the first through hole. Section 4: the first current collecting member has a second region on a side of the first region, a first slit is formed between the first region and the second region; the second region is disposed along an inner surface of the first wall; the second region faces the first wall via the insulating member; Item 4. The electricity storage device according to any one of items 1 to 3. Item 5: The electricity storage device according to item 4, wherein the insulating member is disposed in the first slit. Item 6: the first current collecting member has a third region on an opposite side of the second region with respect to the first region; a second slit is formed between the first region and the third region; the third region is disposed along an inner surface of the first wall; the third region faces the first wall via the insulating member; Item 6. The electricity storage device according to item 4 or 5. Item 7: The electricity storage device according to item 6, wherein the insulating member is disposed in the second slit. Item 8: The electricity storage device according to any one of Items 1 to 7, wherein a first surface treatment portion is provided on the inner surface of the first wall near the periphery of the first through hole, and the first surface treatment portion is in contact with the insulating member. Item 9: The electricity storage device according to item 8, wherein the arithmetic mean roughness of the first surface treatment portion is at least twice as large as the arithmetic mean roughness of the portion of the inner surface of the first wall that is not in contact with the insulating member. Item 10: The electricity storage device according to any one of Items 1 to 9, wherein a second surface treatment portion is provided on at least a portion of the surface of the terminal member that faces the first current collecting member, and the second surface treatment portion is in contact with the insulating member. Item 11: The electricity storage device according to claim 10, wherein the arithmetic mean roughness of the second surface treatment portion is at least twice as large as the arithmetic mean roughness of the untreated portion of the terminal member. Item 12: The electricity storage device according to any one of items 1 to 11, wherein the area of ​​the surface of the terminal member facing the first current collecting member is larger than the area of ​​the upper surface of the protrusion. [Explanation of symbols]

[0098] 10 cases 12 Exterior body 14 1st wall (sealing board) 15 Liquid injection hole 16 Sealing member 17 Gas exhaust valve 18 First through hole 19 Second through hole 20 Electrode group 20a, 20b, 20c electrode body 22 First electrode (positive electrode) 24 2nd electrode (negative electrode) 26 Separator 30 Positive electrode terminal member 40 Negative electrode terminal member 50 Positive electrode current collector 51 Positive electrode first current collecting part 52 Positive electrode second current collecting part 60 Negative electrode current collector 61 Negative electrode first current collecting part 62 Negative electrode second current collecting part 70 First current collecting member 71 First area 72 Protrusion 73 Second area 74 First slit 75 Third area 76 Second slit 77 4th area 78 5th area 80 Insulating material 82 First insulation section 84 Second insulation section 86 Third insulation section 92 First Surface Treatment Section 94 Second Surface Treatment Section 100 Energy storage devices (batteries)

Claims

1. an electrode assembly including a first electrode and a second electrode; a case for accommodating the electrode assembly; a first current collecting member electrically connected to the first electrode; a terminal member connected to the first current collecting member; an insulating member that insulates the first current collecting member and the terminal member from the case; An electricity storage device comprising: the case having a first wall; the first wall has a first through hole; the first current collecting member has a first region disposed along an inner surface of the first wall; The first region is provided with a protruding portion that protrudes toward the first wall, At least a portion of the protrusion is disposed within the first through hole, The terminal member is connected to the protrusion, the insulating member is an integral member having an insulating portion disposed between the first wall and the first current collecting member, and an insulating portion disposed between the first wall and the terminal member. Energy storage device.

2. The power storage device according to claim 1 , wherein the insulating member is disposed on the electrode body side of the protrusion.

3. The power storage device according to claim 1 , wherein an upper surface of the protrusion and the terminal member are connected inside the first through hole.

4. the first current collecting member has a second region on a side of the first region, a first slit is formed between the first region and the second region; the second region is disposed along an inner surface of the first wall; the second region faces the first wall via the insulating member; The electricity storage device according to claim 1 or 2.

5. The power storage device according to claim 4 , wherein the insulating member is disposed in the first slit.

6. the first current collecting member has a third region on the opposite side of the second region with respect to the first region; a second slit is formed between the first region and the third region; the third region is disposed along an inner surface of the first wall; the third region faces the first wall via the insulating member; The electricity storage device according to claim 5 .

7. The power storage device according to claim 6 , wherein the insulating member is disposed in the second slit.

8. The power storage device according to claim 1 , wherein a first surface treatment portion is provided on the inner surface of the first wall near a periphery of the first through hole, and the first surface treatment portion is in contact with the insulating member.

9. The power storage device according to claim 8 , wherein the arithmetic mean roughness of the first surface treated portion is at least twice as large as the arithmetic mean roughness of a portion of the inner surface of the first wall that is not in contact with the insulating member.

10. 3. The electric storage device according to claim 1, wherein a second surface treatment portion is provided on at least a portion of a surface of the terminal member facing the first current collecting member, and the second surface treatment portion is in contact with the insulating member.

11. The electricity storage device according to claim 10 , wherein the arithmetic mean roughness of the second surface treatment portion is at least twice as large as the arithmetic mean roughness of the untreated portion of the terminal member.

12. The electricity storage device according to claim 1 , wherein an area of ​​a surface of the terminal member facing the first current collecting member is larger than an area of ​​an upper surface of the protrusion.

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