Battery

Abstract

To provide a highly reliable battery.SOLUTION: A battery 100 disclosed herein includes: electrode bodies 20 each including first electrodes and second electrodes; a battery case 10 which houses the electrode bodies 20; multiple first electrode tabs 22t connected to the first electrodes; a collector member 50 connected to the first electrode tabs 22t; fixing members 70 each of which bundles the first electrode tabs 22t; and an insulation member 80 disposed between a first surface 14 of the battery case 10 and the electrode body 20. The insulation member 80 has through holes 80h. The first electrode tabs 22t penetrate through the through holes 80h of the insulation member 80.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a battery. [Background technology]

[0002] Conventionally, there is known a battery that includes an electrode assembly having an electrode, a battery case that houses the electrode assembly, a current collecting member electrically connected to the electrode inside the battery case, and a terminal that is electrically connected to the current collecting member inside the battery case and extends to the outside of the battery case. In this type of battery, a plurality of electrode tabs for current collection are provided on the electrode, and the electrode and the current collecting member are sometimes electrically connected via the plurality of electrode tabs (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7035348 [Patent Document 2] Patent No. 7027792 [Patent Document 3] International Publication No. 2018 / 021372 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the capacity of batteries mounted on vehicles and the like has been increasing. As the size of the electrodes increases, the number of electrode tabs attached to the electrodes increases from the viewpoint of reducing resistance. According to the study by the present inventor, as a result, there is a problem that the electrode tabs are likely to vary, making it difficult to stably join them to the current collecting member. In addition, as the size of the electrode body increases, the area of ​​the end face of the electrode body (i.e., the stacking surface where the electrodes are stacked) becomes larger. As a result, there is also a problem that foreign matter such as metal powder is likely to enter the electrode body from the end face when joining members together in a manufacturing process, for example. Therefore, even if the number of electrode tabs increases with increasing capacity, it is required to provide a highly reliable battery that ensures the bond between the electrode tabs and the current collecting member and suppresses the intrusion of foreign matter into the electrode body.

[0005] The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a highly reliable battery. [Means for solving the problem]

[0006] The present invention provides a battery comprising one or more electrode assemblies including a first electrode and a second electrode, a battery case housing the electrode assemblies, a plurality of first electrode tabs connected to the first electrode and disposed at an end of the electrode assemblies, a current collecting member connected to the plurality of first electrode tabs, a fixing member bundling the plurality of first electrode tabs between a portion connected to the first electrode and a portion connected to the current collecting member, and one or more insulating members disposed between a first surface of the battery case and the electrode assemblies, the insulating member having a through hole, and the plurality of first electrode tabs penetrating the through hole of the insulating member.

[0007] By bundling the multiple first electrode tabs with a fixing member as described above, it is possible to suppress variation in the multiple first electrode tabs. This allows the multiple first electrode tabs to be stably joined to the current collecting member, improving the reliability of the joint. In addition, an insulating member is disposed between the battery case and the electrode body, and the first electrode tabs pass through the through holes of the insulating member, which effectively prevents foreign matter from entering the electrode body from the end surface. As described above, a highly reliable battery can be realized according to the present invention. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating a battery according to a first embodiment. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a schematic vertical cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a schematic diagram showing the configuration of the electrode body. [Figure 6] FIG. 6 is a schematic diagram illustrating the bonding step. [Figure 7] FIG. 7 is a view corresponding to FIG. 4 according to the second embodiment. [Figure 8] FIG. 8 is a schematic diagram illustrating the bonding step according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, some preferred embodiments of the technology disclosed herein will be described with reference to the drawings. It should be noted that matters other than those specifically mentioned in this specification and necessary for implementing the technology disclosed herein (for example, the general configuration and manufacturing process of a battery that does not characterize the technology disclosed herein) can be understood as design matters of a person skilled in the art based on the conventional technology in the field. The technology disclosed herein can be implemented based on the contents disclosed in this specification and the technical common sense in the field. It should be noted that the expression "A to B" indicating a range in this specification includes the meaning of "A or more and B or less", as well as "greater than A" and "less than B".

[0010] In this specification, the term "battery" refers to any power storage device capable of extracting electric energy, and is a concept that includes primary batteries and secondary batteries. In addition, in this specification, the term "secondary battery" refers to any power storage device that can be repeatedly charged and discharged by the movement of charge carriers between a positive electrode and a negative electrode via an electrolyte. The electrolyte may be any of a liquid electrolyte (electrolytic solution), a gel electrolyte, and a solid electrolyte. Secondary batteries include so-called storage batteries (chemical batteries) such as lithium ion secondary batteries and nickel metal hydride batteries, as well as capacitors (physical batteries) such as electric double layer capacitors.

[0011] First Embodiment FIG. 1 is a perspective view showing a battery 100. FIG. 2 is a schematic longitudinal sectional view taken along line II-II in FIG. 1. FIG. 3 is a schematic transverse sectional view taken along line III-III in FIG. 1. FIG. 4 is a schematic longitudinal 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. In the drawings, the symbol X represents the short side direction (thickness direction) of the battery 100, the symbol Y represents the long side direction of the battery 100 perpendicular to the short side direction, and the symbol Z represents the up-down direction of the battery 100. However, these directions are merely for the convenience of description, and do not limit the installation form of the battery 100 in any way.

[0012] As shown in Fig. 2, the battery 100 includes a battery case 10, a plurality of electrode bodies 20 (see also Figs. 3 and 4), a positive terminal 30, a negative terminal 40, a positive current collecting member 50, a negative current collecting member 60, a plurality of fixing members 70 (see also Fig. 4), and an insulating member 80 (see also Fig. 4). Although not shown, the battery 100 further includes an electrolyte. The battery 100 is a non-aqueous electrolyte secondary battery. The battery 100 is preferably a secondary battery such as a lithium ion secondary battery.

[0013] The battery case 10 is a housing that houses the electrode body 20. As shown in FIG. 1, the battery case 10 has a flat, bottomed rectangular parallelepiped (square) outer shape. The battery 100 is preferably a square battery having a square battery case 10. The material of the battery case 10 may be the same as that used conventionally, and is not particularly limited. The battery case 10 is preferably made of metal, and more preferably made of, for example, aluminum, aluminum alloy, iron, iron alloy, or the like. As shown in FIG. 2, the battery case 10 includes an exterior body 12 having an opening 12h, and a sealing plate (lid body) 14 that seals the opening 12h. The battery case 10 preferably includes an exterior body 12 and a sealing plate 14. The exterior body 12 and the sealing plate 14 have sizes according to the size of the electrode body 20, the number of the electrodes to be housed (one or more; here, more than one), and the like.

[0014] The exterior body 12 is a bottomed, rectangular container having an opening 12h on the upper surface. As shown in FIG. 1, the exterior body 12 includes a bottom wall 12a, a pair of long side walls 12b extending from the long side of the bottom wall 12a and facing each other, and a pair of short side walls 12c extending from the short side of the bottom wall 12a and facing each other. The bottom wall 12a is substantially rectangular. The bottom wall 12a faces the opening 12h (see FIG. 2). The long side walls 12b have a larger area than the short side walls 12c. The sealing plate 14 is a plate-like member attached to the exterior body 12 so as to close the opening 12h of the exterior body 12. The sealing plate 14 faces the bottom wall 12a of the exterior body 12. The sealing plate 14 is substantially rectangular. The sealing plate 14 is an example of a "first surface". The battery case 10 is integrated by joining (for example, welding) a sealing plate 14 to the periphery of the opening 12h of the exterior body 12. This makes the battery case 10 airtightly sealed (sealed).

[0015] As shown in FIG. 2, the sealing plate 14 is provided with a liquid inlet 15, a gas exhaust valve 17, and terminal outlet holes 18 and 19. The liquid inlet 15 is a through hole for injecting an electrolyte into the battery case 10 after the sealing plate 14 is assembled to the exterior body 12. The liquid inlet 15 is sealed by a sealing member 16 after the electrolyte is injected. The gas exhaust valve 17 is a thin-walled portion configured to break when the pressure inside the battery case 10 reaches or exceeds a predetermined value, thereby discharging the gas inside the battery case 10 to the outside. The terminal outlet holes 18 and 19 are formed at both ends of the sealing plate 14 in the long side direction Y. The terminal outlet holes 18 and 19 penetrate the sealing plate 14 in the up-down direction Z.

[0016] The positive electrode terminal 30 is attached to one end of the sealing plate 14 in the long side direction Y (the left end in Figs. 1 and 2). The negative electrode terminal 40 is attached to the other end of the sealing plate 14 in the long side direction Y (the right end in Figs. 1 and 2). The positive electrode terminal 30 and the negative electrode terminal 40 are preferably attached to the sealing plate 14. The positive electrode terminal 30 and the negative electrode terminal 40 are inserted into the terminal pull-out holes 18, 19, and are partially exposed on the surface of the sealing plate 14. The positive electrode terminal 30 and the negative electrode terminal 40 are connected to other secondary batteries or external devices via external connection members such as bus bars.

[0017] As shown in Fig. 2, the positive electrode terminal 30 is electrically connected to the positive electrode 22 (see Fig. 5) of the electrode body 20 inside the battery case 10 via a positive electrode current collecting member 50 and a positive electrode tab group 25. The positive electrode terminal 30 is preferably made of metal, and more preferably made of aluminum or an aluminum alloy, for example. The positive electrode terminal 30 is insulated from the sealing plate 14 by a gasket 92. The gasket 92 is preferably made of resin.

[0018] The negative electrode terminal 40 is electrically connected to the negative electrode 24 (see FIG. 5) of the electrode body 20 inside the battery case 10 via the negative electrode current collecting member 60 and the negative electrode tab group 27. The negative electrode terminal 40 is preferably made of a metal, and more preferably made of copper or a copper alloy, for example. The negative electrode terminal 40 is insulated from the sealing plate 14 by a gasket 92.

[0019] As shown in Figs. 3 and 4, in the battery 100 of this embodiment, a plurality of electrode bodies 20 (specifically, two) are accommodated in the battery case 10. However, the number of electrode bodies 20 arranged in one battery case 10 is not particularly limited, and may be three or more, or may be one. The plurality of electrode bodies 20 are arranged inside the battery case 10 in a state where they are covered with an electrode body holder 29 made of a resin sheet. This prevents the electrode bodies 20 from coming into direct contact with the exterior body 12.

[0020] The material of the electrode body holder 29 is not particularly limited as long as it has a predetermined insulating property. Examples of such materials include synthetic resin materials such as polyolefin resins such as polypropylene (PP) and polyethylene (PE), and fluorine-based resins such as perfluoroalkoxyalkane and polytetrafluoroethylene (PTFE). As shown in Fig. 4, it is preferable that the upper end of the electrode body holder 29 is approximately aligned with the lower end of a fixing member 70 described later in the vertical direction Z.

[0021] 5 is a schematic diagram showing the configuration of the electrode assembly 20. In FIG. 5 and other figures, the symbol LD indicates the longitudinal direction (i.e., the transport direction) of the electrode assembly 20 manufactured in a strip shape. The symbol WD indicates the direction substantially perpendicular to the longitudinal direction LD and the winding axis direction of the electrode assembly 20. The winding axis direction WD is substantially parallel to the up-down direction Z of the battery 100.

[0022] As shown in FIG. 5, the electrode body 20 is a wound electrode body in which a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked in an insulated state via two strip-shaped separators 26, and wound in the longitudinal direction around the winding axis WL. However, the electrode body 20 may be a laminated electrode body in which a plurality of square-shaped (typically rectangular) positive electrodes and a plurality of square-shaped (typically rectangular) negative electrodes are stacked in an insulated state. As shown in FIG. 2, the end faces of the electrode body 20 (i.e., the lamination surface where the positive electrode 22 and the negative electrode 24 are stacked, both ends in the winding axis direction WD in FIG. 5) face the bottom wall 12a and the sealing plate 14. A positive electrode tab group 25 and a negative electrode tab group 27, which will be described later, protrude from the upper part of the wound electrode body 20. The battery 100 has a so-called upper tab structure in which a positive electrode tab group 25 and a negative electrode tab group 27 are located above the wound electrode body 20. One of the positive electrode 22 and the negative electrode 24 is an example of a first electrode, and the other of the positive electrode 22 and the negative electrode 24 is an example of a second electrode.

[0023] As shown in FIG. 3, the electrode body 20 has a flat outer shape. The electrode body 20 is preferably flat. The flat electrode body 20 has a pair of curved portions 20r with curved outer surfaces and a pair of flat portions 20f with flat outer surfaces that connect the pair of curved portions 20r. The electrode body 20 is accommodated inside the battery case 10 so that the winding axis direction WD substantially coincides with the up-down direction Z. The pair of curved portions 20r face a pair of short side walls 12c of the exterior body 12. The pair of flat portions 20f face a pair of long side walls 12b of the exterior body 12.

[0024] As shown in Fig. 5, the positive electrode 22 is a strip-shaped member. The positive electrode 22 includes a strip-shaped positive electrode collector 22c, and a positive electrode active material layer 22a and a positive electrode protective layer 22p fixed on at least one surface of the positive electrode collector 22c. From the viewpoint of battery performance, the positive electrode active material layer 22a is preferably formed on both sides of the positive electrode collector 22c. However, the positive electrode protective layer 22p is not essential and may be omitted in other embodiments.

[0025] Any conventionally known material that can be used in a general battery (e.g., a lithium ion secondary battery) can be used without particular limitation for each member constituting the positive electrode 22. For example, the positive electrode current collector 22c is preferably made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel, and is a metal foil, specifically an aluminum foil, in this embodiment.

[0026] In the electrode body 20, as shown in FIG. 5, a plurality of positive electrode tabs 22t protrude from a base connected to one end side in the winding axis direction WD toward the outside (the left side in FIG. 5). The "base" is a boundary between the end side of the positive electrode 22 and the positive electrode tab 22t. The plurality of positive electrode tabs 22t are provided at a predetermined interval (intermittently) along the longitudinal direction LD. The number of positive electrode tabs 22t attached to one electrode body 20 can be approximately several tens of sheets or more, for example, about 40 to 60 sheets. The plurality of positive electrode tabs 22t are each connected to the positive electrode 22. Here, the positive electrode tab 22t is a part of the positive electrode 22. The positive electrode tab 22t is a region where the positive electrode active material layer 22a is not formed. The positive electrode current collector 22c is exposed to at least a part of the positive electrode tab 22t. However, the positive electrode tab 22t may be a member separate from the positive electrode 22. Providing a plurality of positive electrode tabs 22t makes it possible to reduce unevenness in resistance and potential within the positive electrode 22. The positive electrode tab 22t is an example of a first electrode tab.

[0027] The positive electrode tab 22t here is substantially rectangular. The protruding length of the positive electrode tab 22t (the vertical length protruding from the base in the winding axis direction WD) may be longer than the electrode tabs disclosed in Patent Documents 1 to 3, for example, and may be approximately 3 mm or more, typically 4 to 10 mm, for example, about 5 to 8 mm. The width of the positive electrode tab 22t (the length in the longitudinal direction LD) is typically shorter than the protruding length of the positive electrode tab 22t, and may be approximately 15 mm or more, for example, 20 to 40 mm. The multiple positive electrode tabs 22t may have different sizes and shapes.

[0028] The positive electrode tabs 22t are stacked at one end of the electrode body 20 in the winding axis direction WD and bundled by a fixing member 70 described later to form a positive electrode tab group 25 (see FIGS. 2 and 4). The positive electrode tabs 22t are bent and curved. The tips of the positive electrode tabs 22t are joined to the positive electrode current collecting member 50. The positive electrode tabs 22t are preferably joined to the positive electrode current collecting member 50 in a bent and curved state. The positive electrode tabs 22t (positive electrode tab group 25) are electrically connected to the positive electrode terminal 30 via the positive electrode current collecting member 50.

[0029] As shown in Fig. 5, the positive electrode active material layer 22a is provided in a strip shape along the longitudinal direction LD of the positive electrode current collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (for example, a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide) that can reversibly store and release charge carriers. The positive electrode active material layer 22a may contain any component other than the positive electrode active material, such as a conductive material, a binder, various additive components, etc. As the conductive material, for example, a carbon material such as acetylene black (AB) can be used. As the binder, for example, polyvinylidene fluoride (PVdF) can be used.

[0030] The positive electrode protective layer 22p is a layer configured to have lower electrical conductivity than the positive electrode active material layer 22a. As shown in FIG. 5, the positive electrode protective layer 22p is provided in a strip shape along the longitudinal direction LD of the positive electrode collector 22c. 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 winding axis direction WD. Here, the positive electrode protective layer 22p is provided at one end of the positive electrode collector 22c in the winding axis direction WD, specifically, at the end on the side where the positive electrode tab 22t is located (the left end in FIG. 5). By providing the positive electrode protective layer 22p, it is possible to prevent the positive electrode 22 from directly contacting the negative electrode active material layer 24a when the separator 26 is damaged, and thus prevent the battery 100 from being internally short-circuited.

[0031] The positive electrode protective layer 22p contains an insulating inorganic filler. An example of the inorganic filler is ceramic particles such as alumina. The positive electrode protective layer 22p may contain any component other than the inorganic filler, such as a binder, a conductive material, and various additive components. The binder and the conductive material may be the same as those exemplified as those that may be contained in the positive electrode active material layer 22a.

[0032] The negative electrode 24 is a strip-shaped member as shown in Fig. 5. The negative electrode 24 includes a strip-shaped negative electrode current collector 24c and a negative electrode active material layer 24a fixed onto at least one surface of the negative electrode current collector 24c. From the viewpoint of battery performance, the negative electrode active material layer 24a is preferably formed on both sides of the negative electrode current collector 24c.

[0033] Any conventionally known material that can be used in a general battery (e.g., a lithium ion secondary battery) can be used without particular limitation for each member constituting the negative electrode 24. For example, the negative electrode current collector 24c is preferably made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel, and is a metal foil, specifically a copper foil, in this embodiment.

[0034] In the electrode body 20, as shown in FIG. 5, a plurality of negative electrode tabs 24t protrude from a base connected to one end side in the winding axis direction WD toward the outside (left side in FIG. 5). The plurality of negative electrode tabs 24t are provided (intermittently) at a predetermined interval along the longitudinal direction LD. In the winding axis direction WD, the negative electrode tabs 24t are provided at the end on the same side (left side in FIG. 5) as the positive electrode tabs 22t. The number of negative electrode tabs 24t attached to one electrode body 20 is approximately equal to the number of positive electrode tabs 22t, and may be approximately several tens of sheets or more, for example, about 40 to 60 sheets. The plurality of negative electrode tabs 24t are each connected to the negative electrode 24. Here, the negative electrode tab 24t is a part of the negative electrode 24. Here, the negative electrode tab 24t is a region where the negative electrode active material layer 24a is not formed and the negative electrode current collector 24c is exposed. However, the negative electrode tab 24t may be a member separate from the negative electrode 24. By providing a plurality of negative electrode tabs 24t, unevenness in resistance and potential within the negative electrode 24 can be reduced.

[0035] The negative electrode tab 24t here is substantially rectangular. The protruding length of the negative electrode tab 24t (the vertical length protruding from the base in the winding axis direction WD) may be longer than the electrode tabs disclosed in Patent Documents 1 to 3, for example, and may be approximately 3 mm or more, typically 4 to 10 mm, for example, about 5 to 8 mm. The width of the negative electrode tab 24t (the length in the longitudinal direction LD) is typically shorter than the protruding length of the negative electrode tab 24t, and may be approximately 15 mm or more, for example, 20 to 40 mm. The multiple negative electrode tabs 24t may have different sizes and shapes.

[0036] The negative electrode tabs 24t are stacked at one end of the electrode body 20 in the winding axis direction WD and bundled by a fixing member 70 described later to form a negative electrode tab group 27 (see Figs. 2 and 4). Although not shown, the negative electrode tabs 24t are bent and curved, similar to the positive electrode tabs 22t. The tip portions of the negative electrode tabs 24t are joined to the negative electrode current collecting member 60. The negative electrode tabs 24t are preferably joined to the negative electrode current collecting member 60 in a bent and curved state. The negative electrode tabs 24t (negative electrode tab group 27) are electrically connected to the positive electrode terminal 30 via the negative electrode current collecting member 60.

[0037] As shown in Fig. 5, the negative electrode active material layer 24a is provided in a strip shape along the longitudinal direction LD of the 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. The negative electrode active material layer 24a may contain any component other than the negative electrode active material, such as a binder, a dispersant, and various additive components. As the binder, for example, rubbers such as styrene butadiene rubber (SBR) can be used. As the dispersant, for example, celluloses such as carboxymethyl cellulose (CMC) can be used.

[0038] As shown in FIG. 5, the separator 26 is a strip-shaped member. 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. The separator 26 constitutes the outer surface of the electrode body 20 here. The separator 26 is preferably a resin porous sheet made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP). The separator 26 may have a substrate part made of a resin porous sheet and a heat resistance layer (HRL) formed on at least one surface of the substrate part. The heat resistance layer is a layer containing an inorganic filler. Examples of the inorganic filler that can be used include alumina, boehmite, aluminum hydroxide, and titania.

[0039] The electrolyte may be any electrolyte used in a general battery (e.g., lithium ion secondary battery) without any particular limitation. An example of the electrolyte is a non-aqueous electrolyte in which a supporting salt is dissolved in a non-aqueous solvent. An example of the non-aqueous solvent is a carbonate-based solvent such as ethylene carbonate, dimethyl carbonate, or ethyl methyl carbonate. An example of the supporting salt is a fluorine-containing lithium salt such as LiPF6. The electrolyte may contain an additive as necessary. However, the electrolyte may be in a solid state (solid electrolyte) and integrated with the electrode body 20.

[0040] The positive electrode current collecting member 50 is a conductive member and constitutes a current path. The positive electrode current collecting member 50 is attached to the sealing plate 14 here. The positive electrode current collecting member 50 electrically connects the positive electrode tab group 25 of the electrode body 20 and the positive electrode terminal 30. As shown in FIG. 2, the positive electrode current collecting member 50 has a plate-shaped first region extending in the long side direction Y along the inner side surface of the sealing plate 14. The positive electrode current collecting member 50 is composed of the first region here. It is preferable that the positive electrode current collecting member 50 has the first region arranged along the surface of the sealing plate 14 on the electrode body 20 side (the lower surface in FIG. 2). This makes it possible to effectively suppress the intrusion of foreign matter into the electrode body 20 described later. One end (the right side in FIG. 2) of the positive electrode current collecting member 50 (specifically the first region) in the long side direction Y is electrically connected to the positive electrode tab group 25, i.e., the stacked multiple positive electrode tabs 22t. The positive electrode current collecting member 50 and the positive electrode tab group 25 are preferably joined (for example, by ultrasonic welding).

[0041] The other end (left side in FIG. 2) of the positive current collecting member 50 (specifically, the first region) in the long side direction Y is electrically connected to the lower end 30c of the positive terminal 30. The positive current collecting member 50 is preferably made of a metal having excellent electrical conductivity, such as aluminum or an aluminum alloy. The positive current collecting member 50 may be made of the same type of metal as the positive tab 22t and / or the positive terminal 30.

[0042] The negative current collecting member 60 is a conductive member and constitutes a current path. Here, the negative current collecting member 60 is attached to the sealing plate 14. The negative current collecting member 60 electrically connects the negative electrode tab group 27 of the electrode body 20 and the negative electrode terminal 40. As shown in FIG. 2, the negative current collecting member 60 has a plate-shaped first region extending in the long side direction Y along the inner side surface of the sealing plate 14. Here, the negative current collecting member 60 is composed of the first region. It is preferable that the negative current collecting member 60 has the first region arranged along the surface of the sealing plate 14 on the electrode body 20 side (the lower surface in FIG. 2). One end (the left side in FIG. 2) of the negative current collecting member 60 (specifically the first region) in the long side direction Y is electrically connected to the negative electrode tab group 27, i.e., the stacked multiple negative electrode tabs 24t. It is preferable that the negative current collecting member 60 and the negative electrode tab group 27 are joined (for example, ultrasonically welded).

[0043] The other end (the right side in FIG. 2) of the negative current collecting member 60 (specifically, the first region) in the long side direction Y is electrically connected to the lower end 40c of the negative terminal 40. The negative current collecting member 60 is preferably made of a metal having excellent electrical conductivity, for example, copper or a copper alloy. The negative current collecting member 60 may be made of the same type of metal as the negative tab 24t and / or the negative terminal 40.

[0044] The positive current collecting member 50 and the negative current collecting member 60 are each insulated from the inner surface of the sealing plate 14 by an internal insulating member 94. The internal insulating member 94 is preferably made of resin. The resin internal insulating member 94 is preferably disposed between the positive current collecting member 50 and the sealing plate 14. The resin internal insulating member 94 is preferably disposed between the negative current collecting member 60 and the sealing plate 14.

[0045] The fixing members 70 are for bundling the positive electrode tabs 22t and the negative electrode tabs 24t. As shown in FIG. 2, the fixing members 70 are attached to the positive electrode tab group 25 (the positive electrode tabs 22t) and the negative electrode tab group 27 (the negative electrode tabs 24t) of the electrode body 20, respectively. As shown in FIG. 4, the fixing members 70 are attached to each electrode body 20. The number of fixing members 70 is typically the number of electrode bodies 20×2 (for the positive electrode tabs 22t and the negative electrode tabs 24t). The number of fixing members 70 is four here. In the following, the positive electrode tabs 22t will be described in detail as an example, but the fixing members 70 can also be attached to the negative electrode tabs 24t in the same manner. The technology disclosed herein is preferably applied to the positive electrode tabs 22t and the negative electrode tabs 24t, respectively.

[0046] As shown in FIG. 4, the multiple positive electrode tabs 22t are maintained in an integrated state by bundling the portion (root portion) connected to the positive electrode 22 and the portion connected to the positive electrode current collecting member 50 with a fixing member 70. According to the study by the present inventor, if the number of positive electrode tabs 22t is about several sheets, it is easy to directly join (typically weld) them to the positive electrode current collecting member 50. However, in a high-capacity battery 100, if the number of positive electrode tabs 22t is several tens or more, the positive electrode tabs 22t are likely to be uneven, and it becomes difficult to stably ensure the joining property with the positive electrode current collecting member 50. Therefore, in the technology disclosed herein, the multiple positive electrode tabs 22t are bundled using the fixing member 70 to form a positive electrode tab group 25. This allows the multiple positive electrode tabs 22t to be stably joined to the positive electrode current collecting member 50, and the joining property (typically weldability) can be improved. As a result, the conduction reliability of the battery 100 can be improved.

[0047] The number of positive electrode tabs 22t bound by the fixing member 70 may be more than one (two or more). From the viewpoint of better exerting the effects of the technology disclosed herein, it is preferable that more than half of the total number of positive electrode tabs 22t attached to one electrode body 20 be bound by one fixing member 70. As shown in FIG. 4, here, all of the positive electrode tabs 22t attached to one electrode body 20 are bound by one fixing member 70. The fixing member 70 may be a conductive member and may constitute a current path from the positive electrode 22 to the positive electrode current collecting member 50. The fixing member 70 is preferably made of a metal having high electrical conductivity.

[0048] The fixing member 70 is preferably a clamping member that holds the positive electrode tabs 22t by clamping them. When the fixing member 70 is a clamping member, the positive electrode tabs 22t are easily folded in a bundled state, and workability can be improved. In addition, welding is not required, and the generation of foreign matter such as metal powder can be suppressed when the positive electrode tabs 22t are fixed to the fixing member 70. In the long side direction Y, the width of the fixing member 70 is preferably larger than the width of the positive electrode tabs 22t. The width of the fixing member 70 in the long side direction Y is larger than the width of the positive electrode tabs 22t, and can be, for example, 15 mm or more, about 20 to 40 mm. The fixing member 70 is preferably one that can stack the positive electrode tabs 22t and maintain a state parallel to the upper end of the electrode body 20 in the long side direction Y.

[0049] 2, an example of the fixing member 70 is a part having a YZ plane portion extending in the long side direction Y and the up-down direction Z, for example, a hollow cylindrical oval sleeve having a tunnel-shaped through hole in the up-down direction Z. When an oval sleeve is used as the fixing member 70, the multiple positive electrode tabs 22t can be fixed to the oval sleeve by inserting the tips of the multiple positive electrode tabs 22t into the through holes of the oval sleeve and then crimping the sleeve. Another example of the fixing member 70 is a plate-shaped clip member having a fixing portion on one or both sides in the long side direction Y, for example, a clip it.

[0050] As shown in FIG. 4, the fixing member 70 is preferably located at the center M of the electrode body 20 in the short side direction X. This ensures that even if the electrode body 20 swells with charging and discharging, electrical continuity with the positive electrode tab 22t located at the outer edge of the electrode body 20 can be reliably maintained. The multiple positive electrode tabs 22t are preferably bundled together at their portions that are substantially perpendicular to the sealing plate 14 by the fixing member 70. This effectively prevents foreign matter from entering the electrode body 20, which will be described later. In this specification, "substantially perpendicular" refers to approximately 92±15° (75 to 105°), preferably 92±10° (80 to 100°), for example 92±5° (85 to 95°).

[0051] The positive electrode tabs 22t are preferably connected to the positive electrode current collecting member 50 in a state where the side (tip e side) closer to the positive electrode current collecting member 50 than the part bundled by the fixing member 70 is bent. This can increase the storage space of the electrode body 20, thereby increasing the energy density of the battery 100. The positive electrode tabs 22t protruding from the upper end of the fixing member 70 are preferably bent (curved) into a substantially L-shape in the state where they are bundled by the fixing member 70. That is, the positive electrode tabs 22t preferably have a curved portion 25b on the side (tip e side) closer to the positive electrode current collecting member 50 than the part bundled by the fixing member 70. This makes it easier for the positive electrode tabs 22t to be bundled together, and can further improve the bondability (typically weldability) with the positive electrode current collecting member 50 attached to the sealing plate 14. It is preferable that the root parts of the positive electrode tabs 22t that are bundled and bent are parallel to each other.

[0052] The insulating member 80 is a cover that covers at least a part of the end face of the electrode body 20. As shown in Fig. 2, the insulating member 80 is disposed between the inner surface of the sealing plate 14 (the lower surface in Fig. 2) and the electrode body 20. More specifically, the insulating member 80 is disposed between the electrode body 20 and the positive electrode current collecting member 50 attached to the sealing plate 14. Here, there is one insulating member 80. However, as in a second embodiment described later, one battery 100 may be provided with a plurality of insulating members 80.

[0053] As shown in Fig. 4, the insulating member 80 has through holes 80h. The number of through holes 80h in the insulating member 80 is typically the number of electrode bodies 20 × 2 (for positive electrode tabs 22t and negative electrode tabs 24t). The number of through holes 80h can be the same as the number of fixing members 70. The number of through holes 80h is four here. The multiple positive electrode tabs 22t pass through the through holes 80h in the insulating member 80 in a state where they are bundled by the fixing members 70 and organized as a positive electrode tab group 25.

[0054] The insulating member 80 is disposed between the sealing plate 14 and the electrode body 20, and the multiple positive electrode tabs 22t penetrate through the through holes 80h provided in the insulating member 80, thereby making it possible to prevent conductive foreign matter that may lead to a decrease in battery performance, such as a voltage drop, from entering the inside of the electrode body 20 from the upper end surface of the electrode body 20. Even if the electrode body 20 moves toward the sealing plate 14 due to the application of an external force, such as vibration or impact, during use of the battery 100, the load on the positive electrode tab group 25 can be reduced. Furthermore, it is possible to prevent the electrode body 20 from coming into contact with a member (e.g., the positive electrode current collecting member 50) attached to the sealing plate 14 and being damaged.

[0055] The insulating member 80 is preferably sized to cover the entire upper end surface of the electrode body 20 in the XY plane view. In the XY plane view, the outer edge of the insulating member 80 is preferably larger than the outer edge of the electrode body holder 29. This can prevent the electrode body 20 and the electrode body holder 29 from directly contacting each other. The insulating member 80 may be disposed inside the electrode body holder 29 or outside the electrode body holder 29. In other words, in the vertical direction Z, the upper end of the electrode body holder 29 may be located below the insulating member 80 or may be located above the insulating member 80. The insulating member 80 may be fixed to the electrode body 20 or the electrode body holder 29 by a fixing means such as a tape. The insulating member 80 may be integral with the electrode body holder 29 and may be a part of the electrode body holder 29.

[0056] The insulating member 80 is preferably made of resin. The material of the insulating member 80 may be the same as the material exemplified for the electrode body holder 29. The material of the insulating member 80 may be the same as the material of the electrode body holder 29, or may be different. The insulating member 80 is preferably made of a material and has a thickness such that the ends in the short side direction X and / or long side direction Y do not bend or curl due to their own weight, and the XY plane can be stably maintained in a flat shape. Therefore, as shown in FIG. 4 and the like, the insulating member 80 is preferably thicker than the electrode body holder 29.

[0057] As shown in FIG. 4, in the thickness direction of the battery 100, in other words, in the direction in which the multiple positive electrode tabs 22t are stacked (short side direction X in FIG. 4), when the width of the through hole 80h of the insulating member 80 is W1 and the total thickness of the bundled portion of the multiple positive electrode tabs 22t is T1, it is preferable that the above W1 and the above T1 satisfy the following formula (1): (W1 / T1)<10;. By minimizing the size of the through hole 80h, it is possible to effectively prevent foreign matter from passing through the through hole 80h and entering the electrode body 20. The above formula (1) is typically 1<(W1 / T1). It is more preferable that the above formula (1) satisfies (W1 / T1)<5.

[0058] As shown in FIG. 4, at least a part of the fixing member 70 is preferably disposed inside the through hole 80h. This can more effectively prevent foreign matter from passing through the through hole 80h and entering the electrode body 20. In this case, when the width of the through hole 80h of the insulating member 80 is W1 and the width of the fixing member 70 is W2 in the thickness direction of the battery 100, in other words, in the direction in which the multiple positive electrode tabs 22t are stacked (short side direction X in FIG. 4), it is preferable that the above W1 and the above W2 satisfy the following formula (2): (W1 / W2)<5;. This can further suppress the intrusion of foreign matter into the electrode body 20 at a higher level. The above formula (2) is typically 1<(W1 / W2). It is more preferable that the above formula (2) satisfies (W1 / W2)<3;.

[0059] The battery 100 can be manufactured, for example, by a method including the following steps, typically in this order: (Step 1) electrode preparation step; (Step 2) electrode assembly fabrication step; (Step 3) tab fixing step; (Step 4) electrode assembly housing step; (Step 5) bonding step; and (Step 6) sealing step. The manufacturing method disclosed herein may further include other steps at any stage.

[0060] In (Step 1) an electrode preparation process, a strip-shaped positive electrode 22 having a plurality of positive electrode tabs 22t and a strip-shaped negative electrode 24 having a plurality of negative electrode tabs 24t are prepared. In (Step 2) an electrode body preparation process, first, the strip-shaped positive electrode 22 and the strip-shaped negative electrode 24 are stacked with a strip-shaped separator 26 interposed therebetween, and then wound in the longitudinal direction around the winding axis WL to form a cylindrical shape. At this time, the plurality of positive electrode tabs 22t and the plurality of negative electrode tabs 24t are adjusted so that they protrude from the same end side and are stacked at different positions. Next, the electrode body (cylindrical body) wound into a cylindrical shape is, for example, press-molded into a flat shape to produce a flat-shaped electrode body 20 (see FIG. 5).

[0061] (Step 3) In the tab fixing process, the multiple positive electrode tabs 22t and the multiple negative electrode tabs 24t are bundled with the fixing member 70, respectively, and the collected foil state is fixed. Note that this process is preferably performed simultaneously when the electrode body 20 is molded. The fixing position of the fixing member 70 is preferably as close as possible to the electrode body 20, from the viewpoint of expanding the accommodation space of the electrode body 20, etc. The multiple positive electrode tabs 22t are bundled with the fixing member 70 and integrated into a positive electrode tab group 25. Similarly, the multiple negative electrode tabs 24t are bundled with the fixing member 70 and integrated into a negative electrode tab group 27.

[0062] (Step 4) In the electrode assembly accommodating step, the electrode assembly 20 is inserted into the electrode assembly holder 29, and then the electrode assembly 20 wrapped in the electrode assembly holder 29 is accommodated in the exterior body 12 so that the positive electrode tab group 25 and the negative electrode tab group 27 face upward. Next, an insulating member 80 having a plurality of through holes 80h is prepared, and the positive electrode tab group 25 and the negative electrode tab group 27 are inserted into the plurality of through holes 80h of the insulating member 80, respectively. As a result, the insulating member 80 is arranged to cover the upper end surface of the electrode assembly 20.

[0063] (Step 5) In the joining process, the tip side of the positive electrode tab group 25 and the tip side of the negative electrode tab group 27 protruding from the upper end of the fixing member 70 are each bent into a substantially L-shape with respect to the fixing member 70. In addition, the positive electrode terminal 30, the negative electrode terminal 40, the positive electrode current collecting member 50, and the negative electrode current collecting member 60 are attached to the sealing plate 14. Next, as shown in FIG. 6, the tip portion of the positive electrode tab group 25 is joined (for example, welded joint) to the positive electrode current collecting member 50 attached to the sealing plate 14. In addition, the tip portion of the negative electrode tab group 27 is joined to the negative electrode current collecting member 60 attached to the sealing plate 14. As a result, a joint (for example, a welded joint) J between the positive electrode current collecting member 50 and the positive electrode tab group 25 is formed, and a joint (for example, a welded joint) J between the negative electrode current collecting member 60 and the negative electrode tab group 27 is formed.

[0064] (Step 6) In the sealing process, the leading ends of the positive electrode tab group 25 and the leading ends of the negative electrode tab group 27 are each bent and curved into a substantially U-shape, and the sealing plate 14 is fitted into the opening 12h of the exterior body 12, and the periphery of the opening 12h of the exterior body 12 and the sealing plate 14 are joined (for example, welded) to each other. This hermetically seals the battery case 10. In this manner, the battery 100 can be manufactured.

[0065] <Second embodiment> FIG. 7 is a view corresponding to FIG. 4 according to the second embodiment. As shown in FIG. 7, the battery 200 of this embodiment includes a plurality of electrode bodies and a plurality of insulating members. The plurality of electrode bodies includes a first electrode body 20a and a second electrode body 20b. The plurality of insulating members includes a first insulating member 80a and a second insulating member 80b. The first insulating member 80a and the second insulating member 80b are separate members (separate members). The number of insulating members 80 provided in one battery 200 is typically the same as the number of electrode bodies 20. The number of insulating members 80 is two here. The plurality of positive electrode tabs 22t connected to the first electrode body 20a are bundled with a fixing member 70 and pass through the through hole 80h of the first insulating member 80a. The plurality of positive electrode tabs 22t connected to the second electrode body 20b are bundled with a fixing member 70 and pass through the through hole 80h of the second insulating member 80b. This improves assembly and allows efficient manufacture of the battery 200. Also, intrusion of foreign matter into the electrode body 20 can be effectively prevented.

[0066] The battery 200 can be manufactured, for example, by a manufacturing method including, in this order, (Step 4A) a bonding step and (Step 5A) an electrode assembly accommodating step, instead of Steps 4 and 5 of the first embodiment.

[0067] In the joining step (Step 4A), as shown in FIG. 8, a plurality of positive electrode tabs 22t and a plurality of negative electrode tabs 24t are inserted into the through holes 80h of the first insulating member 80a and the second insulating member 80b, respectively. As a result, the first insulating member 80a is placed so as to cover the upper end surface of the first electrode body 20a, and the second insulating member 80b is placed so as to cover the upper end surface of the second electrode body 20b. Next, the positive electrode terminal 30, the negative electrode terminal 40, the positive electrode current collector 50, and the negative electrode current collector 60 are attached to the sealing plate 14. Next, the tip portions of the plurality of positive electrode tabs 22t of the first electrode body 20a and the second electrode body 20b are joined (for example, welded) to the positive electrode current collector 50 attached to the sealing plate 14. Furthermore, the tip portions of the multiple negative electrode tabs 24t of the first electrode body 20a and the second electrode body 20b are joined (e.g., welded) to the negative electrode current collecting member 60 attached to the sealing plate 14. This forms a joint (e.g., welded joint) J between the positive electrode current collecting member 50 and the multiple positive electrode tabs 22t, and a joint (e.g., welded joint) J between the negative electrode current collecting member 60 and the multiple negative electrode tabs 24t.

[0068] (Step 5A) In the electrode body accommodating process, the tip e side of the positive electrode tab group 25 and the tip e side of the negative electrode tab group 27 protruding from the upper end of the fixing member 70 are each bent into a substantially L shape with respect to the fixing member 70. Next, the electrode body 20 is inserted into the electrode body holder 29, and then the electrode body 20 wrapped in the electrode body holder 29 is accommodated in the exterior body 12.

[0069] <Battery uses> Although the battery 100 can be used for various purposes, it is suitable for use in applications requiring high capacity or applications in which external forces such as vibrations and shocks may be applied during use, such as a power source (driving power source) for a motor mounted on a moving body (typically a vehicle such as a passenger car or truck). The type of vehicle is not particularly limited, and examples include a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), and a battery electric vehicle (BEV).

[0070] Although several embodiments of the present invention have been described above, the above embodiments are merely examples. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in the field. The technology described in the claims includes various modifications and changes to the above-exemplified embodiments. For example, it is possible to replace a part of the above-mentioned embodiment with another modified form, and it is also possible to add another modified form to the above-mentioned embodiment. Furthermore, if a technical feature is not described as essential, it is also possible to delete it as appropriate.

[0071] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Item 1: A battery comprising: one or more electrode assemblies including a first electrode and a second electrode; a battery case accommodating the electrode assemblies; a plurality of first electrode tabs connected to the first electrode and arranged at an end of the electrode assembly; a current collecting member connected to the plurality of first electrode tabs; a fixing member bundling the plurality of first electrode tabs between a portion connected to the first electrode and a portion connected to the current collecting member; and one or more insulating members arranged between a first surface of the battery case and the electrode assembly, wherein the insulating member has a through hole, and the plurality of first electrode tabs pass through the through hole of the insulating member. Item 2: The battery according to item 1, wherein, in a direction in which the plurality of first electrode tabs are stacked, when a width of the through hole of the insulating member is W1 and a total thickness of a bundled portion of the plurality of first electrode tabs is T1, W1 and T1 satisfy the following formula: (W1 / T1)<10. Item 3: The battery described in item 1 or 2, wherein the electrode body includes a first electrode body and a second electrode body, the insulating member includes a first insulating member and a second insulating member, the plurality of first electrode tabs connected to the first electrode body pass through the through holes of the first insulating member, and the plurality of first electrode tabs connected to the second electrode body pass through the through holes of the second insulating member. Item 4: The battery according to any one of items 1 to 3, wherein at least a portion of the fixing member is disposed inside the through hole. Item 5: The battery according to item 4, wherein, in a direction in which the plurality of first electrode tabs are stacked, when the width of the through hole of the insulating member is W1 and the width of the fixing member is W2, W1 and W2 satisfy the following formula: (W1 / W2)<5. Item 6: The battery according to any one of items 1 to 5, wherein the first electrode tabs are bundled together by the fixing member at portions that are approximately perpendicular to the first surface of the battery case. Item 7: The battery according to any one of items 1 to 6, wherein the first electrode tabs are connected to the current collecting member in a bent state on a side closer to the current collecting member than the portion bundled by the fixing member. Item 8: The battery described in any one of items 1 to 7, wherein the current collecting member has a first region arranged along the first surface of the battery case, and a plurality of the first electrode tabs are stacked and connected to the first region. [Explanation of symbols]

[0072] 10 Battery case 12 Exterior body 14 Sealing plate 20, 20a, 20b electrode body 22 Positive electrode 22t Positive electrode tab 24 Negative electrode 24t negative electrode tab 70 Fixing member 80, 80a, 80b Insulating member 100, 200 batteries

Claims

1. a first electrode body and a second electrode body each including a first electrode and a second electrode; a battery case that accommodates the first electrode body and the second electrode body; a plurality of first electrode tabs of the first electrode body connected to the first electrodes and disposed at ends of the first electrode body; a plurality of first electrode tabs of the second electrode body connected to the first electrodes and disposed at ends of the second electrode body; a current collecting member connected to the first electrode tabs of the first electrode body and the first electrode tabs of the second electrode body; a first fixing member that bundles the first electrode tabs of the first electrode body between a portion connected to the first electrode and a portion connected to the current collecting member; a second fixing member that bundles the first electrode tabs of the second electrode body between a portion connected to the first electrode and a portion connected to the current collecting member; a first insulating member disposed between the first surface of the battery case and the first electrode body, the first insulating member having a first through hole; a second insulating member disposed between the first surface of the battery case and the second electrode body, the second insulating member having a second through hole; Equipped with the first insulating member and the second insulating member are separate parts, the first electrode tabs of the first electrode body pass through the first through holes of the first insulating member; The first electrode tabs of the second electrode body pass through the second through holes of the second insulating member. battery.

2. In a direction in which the multiple first electrode tabs of the first electrode body are stacked, when the width of the first through hole of the first insulating member is W1 and the total thickness of the bundled portion of the multiple first electrode tabs of the first electrode body is T1, W1 and T1 satisfy the following formula: (W1 / T1)<10; 10. The battery of claim 1.

3. At least a portion of the first fixing member is disposed inside the first through hole.

3. The battery of claim 1 or 2.

4. In a direction in which the multiple first electrode tabs of the first electrode body are stacked, when the width of the first through hole of the first insulating member is W1 and the width of the first fixing member is W2, W1 and W2 satisfy the following formula: (W1 / W2)<5; 4. The battery of claim 3.

5. The first electrode tabs of the first electrode body are bundled by the first fixing member at portions that are approximately perpendicular to the first surface of the battery case.

3. The battery of claim 1 or 2.

6. The first electrode tabs of the first electrode body are connected to the current collecting member in a state in which the side closer to the current collecting member than the portion bundled by the first fixing member is bent.

3. The battery of claim 1 or 2.

7. the current collecting member has a first region disposed along the first surface of the battery case, The first electrode tabs of the first electrode body are stacked and connected to the first region.

3. The battery of claim 1 or 2.

8. one or more electrode bodies including a first electrode and a second electrode; A battery case that houses the electrode assembly; a plurality of first electrode tabs connected to the first electrodes and disposed at ends of the electrode body; a current collecting member connected to a plurality of the first electrode tabs; a fixing member that bundles the first electrode tabs between a portion connected to the first electrode and a portion connected to the current collecting member; One or more insulating members disposed between the first surface of the battery case and the electrode body; Equipped with The insulating member has a through hole, the first electrode tabs pass through the through holes of the insulating member; At least a portion of the fixing member is disposed inside the through hole. battery.

9. The fixing member is a conductive member.

9. The battery of claim 8.

10. one or more electrode bodies including a first electrode and a second electrode; A battery case that houses the electrode assembly; a plurality of first electrode tabs connected to the first electrodes and disposed at ends of the electrode body; a current collecting member connected to a plurality of the first electrode tabs; a fixing member that bundles the first electrode tabs between a portion connected to the first electrode and a portion connected to the current collecting member; One or more insulating members disposed between the first surface of the battery case and the electrode body; Equipped with The insulating member has a through hole, the first electrode tabs pass through the through holes of the insulating member; the first electrode tabs are connected to the current collecting member in a bent state at a side closer to the current collecting member than the portion bundled by the fixing member; battery.

11. The fixing member is a conductive member. The battery of claim 10.

12. one or more electrode bodies including a first electrode and a second electrode; A battery case that houses the electrode assembly; a plurality of first electrode tabs connected to the first electrodes and disposed at ends of the electrode body; a current collecting member connected to a plurality of the first electrode tabs; a fixing member that bundles the first electrode tabs between a portion connected to the first electrode and a portion connected to the current collecting member; One or more insulating members disposed between the first surface of the battery case and the electrode body; Equipped with The insulating member has a through hole, the first electrode tabs pass through the through holes of the insulating member; The electrode body includes a first electrode body and a second electrode body, the insulating member has a first through hole and a second through hole formed at a position spaced apart from the first through hole, The first electrode tabs connected to the first electrode body pass through the first through holes, The first electrode tabs connected to the second electrode body pass through the second through holes, The first electrode tabs connected to the first electrode body and the second electrode tabs connected to the second electrode body are overlapped and joined to the current collecting member. battery.

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