Batteries and battery modules

Abstract

To provide a battery in which stress is less likely to occur at the joint between the current collection terminals and current collection tabs, even when adjacent current collection terminals are joined together. [Solution] A battery comprising an electrode body and a plurality of current-collecting tabs extending from its side surface, a current-collecting terminal connected to the current-collecting tabs, and a laminate film housing the electrode body and the plurality of current-collecting tabs, wherein the current-collecting tab has a base portion which is the end on the electrode body side, a connection portion for connecting to the current-collecting terminal, and an intermediate portion connecting the base portion and the connection portion, the plurality of current-collecting tabs each have a laminated connection portion in which the connection portions are stacked in the thickness direction, the current-collecting terminal has an inner surface facing the side surface of the electrode body and a side surface arranged along the outer edge of the inner surface, the laminate film is placed on the side surface of the current-collecting terminal and the main surface of the laminated connection portion is joined to the inner surface, and in a plan view in the stacking direction, the current-collecting terminal has a base portion including a first end corresponding to the position on the inner surface and a second end facing the first end, and a projection portion that protrudes from the base portion on the side opposite to the electrode body.

Description

[Technical Field]

[0001] This disclosure relates to batteries and battery modules. [Background technology]

[0002] Batteries such as lithium-ion secondary batteries typically comprise an electrode assembly having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector. The electrode assembly is sealed by an outer casing. Electricity generated in the electrode assembly is led from the inside of the outer casing to the outside by current collection terminals. For example, Patent Document 1 discloses a stacked or stacked / folded electrode assembly with a positive electrode / separator / negative electrode structure. Figure 2 of Patent Document 1 also discloses the connection of multiple tabs (e.g., positive electrode tabs 40) in a densely packed configuration to a lead (e.g., positive electrode lead 60). Furthermore, Patent Document 1 discloses the use of a laminate sheet (laminate film) as the outer casing. Similarly, Patent Documents 2 and 3 also disclose the use of a laminate film as the outer casing. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 5550805 [Patent Document 2] Japanese Patent Publication No. 2011-108623 [Patent Document 3] Japanese Patent Publication No. 2020-115423 [Overview of the project] [Problems that the invention aims to solve]

[0004] When stacking multiple batteries (battery cells) and joining adjacent current collection terminals, stress is generated at the joint between the current collection terminal and the current collection tab, which may reduce the strength of the joint between the current collection terminal and the current collection tab, or cause damage to the current collection tab.

[0005] This disclosure has been made in view of the above circumstances, and its main purpose is to provide a battery in which stress is less likely to occur at the joint between the current collection terminals and current collection tabs, even when multiple batteries are stacked and adjacent current collection terminals are joined together. [Means for solving the problem]

[0006] [1] A battery comprising an electrode body, a plurality of current-collecting tabs extending from the side portion of the electrode body, a current-collecting terminal connected to the plurality of current-collecting tabs, and a laminate film housing the electrode body and the plurality of current-collecting tabs, wherein the current-collecting tab has a base portion which is the end portion on the electrode body side, a connection portion for connecting to the current-collecting terminal, and an intermediate portion connecting the base portion and the connection portion, and each of the plurality of current-collecting tabs has a laminated connection portion which is stacked in the thickness direction, A battery comprising: a current collector terminal having an inner surface facing the side surface of the electrode body and a side surface arranged along the outer edge of the inner surface, the laminate film being placed on the side surface of the current collector terminal and the main surface of the laminated connection portion being joined to the inner surface, and in a plan view in the lamination direction of the electrode body, the current collector terminal having a base portion including a first end corresponding to the position of the inner surface and a second end facing the first end, and a projection portion protruding from the base portion on the side opposite to the electrode body.

[0007] [2] The battery according to [1], wherein in a cross-sectional view of the electrode body in the stacking direction, the intermediate portion has a curved structure in which parts of the intermediate portion face each other.

[0008] [3] The current collector terminal has, as the protruding portion, a first protruding portion and a second protruding portion. In a plan view in the stacking direction of the electrode body, the direction of opposition between the electrode body and the current collector terminal is defined as D1, the direction orthogonal to D1 is defined as D2, and when an axis that is parallel to D1 and passes through the midpoint of the current collector terminal in D2 is defined as AX, the first protruding portion is disposed in one region of the current collector terminal partitioned by AX, and the second protruding portion is disposed in the other region of the current collector terminal partitioned by AX. The battery according to [1] or [2].

[0009] [4] A battery module in which a plurality of batteries are stacked, wherein the battery is the battery according to any one of [1] to [3].

[0010] [5] A battery module in which a plurality of batteries are stacked, wherein the battery is the battery according to [3]. The battery module has, as the battery, battery A, battery B, and battery C. Battery A, battery B, and battery C are stacked continuously. The first protruding portions of battery A, the first protruding portion of battery B, and the first protruding portion of battery C are arranged such that at least a part of each overlaps in a plan view in the stacking direction of the electrode body. The second protruding portions of battery A, the second protruding portion of battery B, and the second protruding portion of battery C are arranged such that at least a part of each overlaps in a plan view in the stacking direction of the electrode body. The first protruding portion of battery B is joined to the first protruding portion of battery A and is not joined to the first protruding portion of battery C. The second protruding portion of battery B is not joined to the second protruding portion of battery A and is joined to the second protruding portion of battery C. Battery module. [Effect of the Invention]

[0011] In the present disclosure, even when a plurality of batteries are stacked, there is an effect that a battery in which stress is unlikely to occur at the joint portion of the current collector terminal and the current collector tab can be provided. [Brief Description of the Drawings]

[0012] [Figure 1] This is a schematic perspective view illustrating a battery in this disclosure. [Figure 2] These are schematic plan and side views illustrating the battery in this disclosure. [Figure 3] This is a cross-sectional view of AA in Figure 2. [Figure 4] This is a schematic plan view illustrating the current collection terminal and its surroundings in this disclosure. [Figure 5] These are schematic perspective and side views illustrating a conventional battery. [Figure 6] These are schematic perspective and side views illustrating the battery described in this disclosure. [Figure 7] This is a schematic plan view illustrating the current collection terminals in this disclosure. [Figure 8] This is a schematic perspective view illustrating the current collection terminal in this disclosure. [Figure 9] This is a schematic cross-sectional view illustrating an example of an electrode body in this disclosure. [Figure 10] This is a schematic perspective view illustrating the battery manufacturing method described in this disclosure. [Figure 11] This is a schematic perspective view illustrating a battery module in this disclosure. [Figure 12] This is a schematic perspective view illustrating a battery module in this disclosure. [Modes for carrying out the invention]

[0013] The batteries and battery modules described herein will be explained in detail below with reference to the drawings. The following figures are schematic representations, and the size and shape of each part have been exaggerated as appropriate for ease of understanding. In addition, hatching of parts may be omitted as appropriate.

[0014] A.Battery Figure 1 is a schematic perspective view illustrating a battery in this disclosure. Figures 2(a) and 2(b) are schematic plan views illustrating a battery in this disclosure, and Figure 2(c) is a schematic side view illustrating a battery in this disclosure. As shown in Figures 1 and 2, the battery 100 comprises an electrode body 10 and a side portion S of the electrode body 10. 10 It comprises a plurality of current collection tabs 20 extending from the electrode body, a current collection terminal 30 (first current collection terminal 30A and second current collection terminal 30B) connected to the plurality of current collection tabs 20, and a laminate film 40 that houses the electrode body 10 and the plurality of current collection tabs 20.

[0015] Figure 3 is a cross-sectional view of AA in Figure 2. As shown in Figure 3, the current collector tab 20 has a base portion X which is the end on the electrode body 10 side, a connection portion Y for connecting to the current collector terminal 30, and an intermediate portion Z connecting the base portion X and the connection portion Y. In addition, each of the multiple current collector tabs 20 has a stacked connection portion W in which the connection portion Y is stacked in the thickness direction (vertical direction in Figure 3). The current collector terminal 30 is on the side portion S of the electrode body 10. 10 It has an inner surface S1 facing the front, an outer surface S2 facing the inner surface S1, and four side surfaces (S3, S4, S5, S6) arranged along the outer edge of the inner surface S1. Note that side surfaces S4 and S6 are not shown in Figure 3. As shown in Figure 2(c), laminate film 40 is arranged on the four side surfaces S3 to S6. As shown in Figure 3, the main surface of the laminated connection part W is joined to the inner surface S1 of the current collection terminal 30.

[0016] Figure 4 is a schematic plan view illustrating the current collector terminal and its surroundings in this disclosure. As shown in Figure 4, the current collector terminal 30 has a base portion 31 including a first end portion T1 corresponding to the position of the inner surface S1 and a second end portion T2 facing the first end portion T1, and a projection portion 32 that protrudes from the base portion 31 on the side opposite to the electrode body 10.

[0017] According to this disclosure, by using a predetermined current collection terminal, even when multiple batteries are stacked and adjacent current collection terminals are joined, a battery is made in which stress is less likely to occur at the joint between the current collection terminal and the current collection tab. Here, Figure 5(a) is a schematic perspective view illustrating a conventional battery, and Figure 5(b) is a schematic side view of the battery shown in Figure 5(a) observed from the bottom of the drawing. Also, Figure 6(a) is a schematic perspective view illustrating a battery in this disclosure, and Figure 6(b) is a schematic side view of the battery shown in Figure 6(a) observed from the bottom of the drawing. As shown in Figures 5(a) and (b), in conventional batteries, the joint between the current collection terminal 30 and the current collection tab 20 was located on the main surface of the current collection terminal 30 (the surface whose normal direction coincides with the thickness direction). Because the thickness of the current collection terminal 30 is thin, when multiple batteries are stacked, the position of the current collection terminal 30 in the thickness direction changes significantly. As a result, large stresses are generated at the joint between the current collector terminal 30 and the current collector tab 20, which may lead to a decrease in the joint strength between the current collector terminal and the current collector tab, or damage to the current collector tab. In contrast, as shown in Figures 6(a) and (b), this disclosure uses a current collector terminal 30 having an inner surface S1 that can make surface contact with the main surface of the stacked connection portion W. That is, because the current collector terminal 30 is thick, the positional change of the current collector terminal 30 in the thickness direction is small when stacking multiple batteries. As a result, the generation of large stresses at the joint between the current collector terminal 30 and the current collector tab 20 can be suppressed. Furthermore, because the current collector terminal 30 has a protrusion 32, there is an advantage that the positional change of the current collector terminal 30 in the thickness direction is small when stacking multiple batteries compared to when there is no protrusion 32. In particular, as will be described later, when multiple current collector tabs 20 have a curved structure, even if stress is generated at the joint between the current collector terminal 30 and the current collector tab 20, the curved structure makes it easier to distribute the stress.

[0018] 1. Battery configuration The battery in this disclosure comprises an electrode body, a plurality of current-collecting tabs extending from the side portion of the electrode body, a current-collecting terminal connected to the plurality of current-collecting tabs, and a laminate film housing the electrode body and the plurality of current-collecting tabs.

[0019] (1) Electrode body The electrode body in this disclosure typically comprises a power generation unit having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector in this order in the thickness direction. The shape of the electrode body is not particularly limited, but preferably it has a top surface, a bottom surface facing the top surface, and four side surfaces connecting the top surface and the bottom surface. The shape of the top surface is not particularly limited, but examples include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The shape of the top surface may also be a polygon other than a quadrilateral, or a curved shape such as a circle. The shape of the bottom surface is the same as the shape of the top surface. The shape of the side surfaces is not particularly limited, but examples include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms.

[0020] (2) Multiple current collection tabs The multiple current-collecting tabs in this disclosure are arranged to extend from the side portion of the electrode body. The "side portion of the electrode body" refers to the portion that constitutes the electrode body and whose normal direction intersects the stacking direction of the electrode body. For example, in Figure 3, the side portion S of the electrode body 10. 10 The normal direction of the electrode (vertical direction in the drawing) is perpendicular to the stacking direction of the electrode body 10 (horizontal direction in the drawing). Furthermore, "stacking direction of the electrode body" refers to the thickness direction of each layer that makes up the electrode body.

[0021] As shown in Figure 3, the current collector tab 20 has a base portion X which is the end on the electrode body 10 side, a connection portion Y for connecting to the current collector terminal 30, and an intermediate portion Z connecting the base portion X and the connection portion Y. The base portion X is the end (boundary portion) of the current collector tab 20 on the electrode body 10 side. The connection portion Y is the part for connecting to the current collector terminal 30 and is the part that constitutes the laminated connection portion W described later. The intermediate portion Z is the part that connects the base portion X and the connection portion Y. In this disclosure, each of the multiple current collector tabs has a laminated connection portion in which the connection portion is stacked in the thickness direction. In Figure 3, each connection portion Y of the multiple current collector tabs 20 is stacked in the thickness direction of the current collector tab 20, thereby forming a laminated connection portion W. In the laminated connection portion W, each connection portion Y is joined to each other (fixed to each other).

[0022] As shown in Figure 3, in a cross-sectional view of the electrode body 10 in the stacking direction, it is preferable that the intermediate portion Z has a curved structure (area shown by dashed lines) in which parts of the intermediate portion Z face each other. In Figure 3, the intermediate portion Z of the rightmost current collector tab 20 among the multiple current collector tabs 20 does not have the curved structure because parts of the intermediate portion Z do not face each other, but the intermediate portions Z of the other multiple current collector tabs 20 all have the curved structure. Thus, it is preferable that the intermediate portion Z of at least one of the multiple current collector tabs 20 has the curved structure. In the curved structure, the parts of the opposing intermediate portions Z may be arranged to be in direct contact with each other, or they may be arranged with a space between them. Also, as shown in Figure 3, it is preferable that the intermediate portions Z of the multiple current collector tabs 20 are curved in a U-shape.

[0023] (3) Current collector terminal The current collector terminal in this disclosure has an inner surface facing the side surface of the electrode body and a side surface arranged along the outer edge of the inner surface. The shape of the inner surface is not particularly limited, but examples include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The number of side surfaces is, for example, multiple. The number of side surfaces depends, for example, on the shape of the outer edge of the inner surface. For example, if the shape of the outer edge of the inner surface is quadrilateral, the current collector terminal may have four side surfaces. The current collector terminal may also have an outer surface facing the inner surface. The inner surface usually corresponds to a surface within the area sealed by the laminate film. The outer surface usually corresponds to a surface outside the area sealed by the laminate film. The base and protrusions described later may each have an outer surface facing the inner surface. The inner surface, side surfaces, and outer surface may each be planar or curved.

[0024] As shown in Figure 4, in plan view, the current collector terminal 30 has a base portion 31 and a projection portion 32. The base portion 31 includes a first end portion T1 corresponding to the position of the inner surface S1 and a second end portion T2 facing the first end portion T1. In Figure 4, the second end portion T2 is on the outer surface S 21corresponds to the position. Further, as shown in FIG. 4, the facing direction of the electrode body 10 and the current collecting terminal 30 is defined as D1, and the direction orthogonal to D1 is defined as D2. The base portion 31 corresponds to the portion from the position of the first end portion T1 to the position of the second end portion T2 in the direction D1. The base portion 31 of the current collecting terminal 30 may have an inner surface S1, an outer surface S2 facing the inner surface S1, and four side surfaces (S3, S4, S5, S6) arranged along the outer edge of the inner surface S1. Examples of the shape of the base portion 31 include a rectangular parallelepiped. On the other hand, in the direction D1, the protruding portion 32 is a portion that protrudes from the base portion 31 to the side opposite to the electrode body 10. In FIG. 4, the protruding portion 32 has a third end portion T3 corresponding to the position of 22 The third end portion T3 is located outside (on the side opposite to the electrode body 10) the second end portion T2 in the direction D1. Examples of the shape of the protruding portion 32 include a rectangular parallelepiped. The protruding portion 32 is preferably formed continuously from the base portion 31.

[0025] The current collecting terminal in the present disclosure may have a plurality of protruding portions. In FIG. 4, the current collecting terminal 30 has a first protruding portion 32a and a second protruding portion 32b as the protruding portions 32. As shown in FIG. 4, an axis parallel to the direction D1 and passing through the midpoint C of the current collecting terminal 30 in the direction D2 is defined as AX. It is preferable that the first protruding portion 32a is arranged in one region of the current collecting terminal 30 partitioned by the axis AX, and the second protruding portion 32b is arranged in the other region of the current collecting terminal 30 partitioned by the axis AX. As shown in FIG. 4, the current collecting terminal 30 preferably has a U shape. Further, as shown in FIG. 7, the current collecting terminal 30 may have one protruding portion 32. The current collecting terminal 30 shown in FIG. 7 has a T shape.

[0026] As shown in FIG. 8, the length of the current collecting terminal 30 in the direction D1 is defined as L1, the length of the current collecting terminal 30 in the direction D2 is defined as L2, and the length of the current collecting terminal 30 in the direction D3 (a direction orthogonal to both D1 and D2) is defined as L3. Also, the length of the base portion in the direction D1 is L 11 and the length of the protruding portion in the direction D1 is L 12 Let it be. L 11 With respect to L 12The ratio (L 12 / L 11 For example, ) is between 0.5 and 5, and may be between 1 and 3. 11 and L 12 These are, for example, 0.5 cm or more and 5 cm or less, respectively. L2 may be greater than L1. The ratio of L2 to L1 (L2 / L1) is, for example, 2 or more, may be 5 or more, or may be 10 or more. L2 may be greater than L3. The ratio of L2 to L3 (L2 / L3) is, for example, 5 or more, may be 10 or more, or may be 50 or more. L1 may be greater than L3. The ratio of L1 to L3 (L1 / L3) is, for example, 2 or more, may be 5 or more, or may be 10 or more.

[0027] Although not specifically shown in the diagram, the length of the electrode body in direction D1 is L. X Let L be the length of the electrode body in direction D2. Y Let L be the length of the electrode body in direction D3. Z Let's assume that. L X The ratio of L1 to (L1 / L X ) is not particularly limited to L Y The ratio of L2 to (L2 / L Y For example, L2 / L is 0.8 or higher, may be 0.9 or higher, or may be 0.95 or higher. Y For example, L is less than or equal to 1.0. Z The ratio of L3 to (L3 / L Z For example, it may be 0.8 or higher, 0.9 or higher, or 0.95 or higher. L3 / L Z For example, it is 1.0 or less.

[0028] When the battery is viewed from the side, from the current collection terminal side, the inner surface of the current collection terminal and the side surface of the electrode body are arranged to overlap. The area where the inner surface of the current collection terminal and the side surface of the electrode body overlap is called the overlapping area. Area S of the side surface of the electrode body. A The area S of the overlapping region B The proportion (S B / S A) is, for example, 80% or more, may be 90% or more, or may be 95% or more. On the other hand, S B / S A It is less than 100%.

[0029] As shown in Figure 3, the main surface of the laminated connection portion W is joined to the inner surface S1 of the current collection terminal 30. The "main surface of the laminated connection portion W" refers to the surface that constitutes the laminated connection portion W and whose normal direction coincides with the thickness direction of the connection portion Y. The main surface of the laminated connection portion W may be joined to the inner surface S1 by direct contact, or it may be joined via another member (for example, a conductive layer). The inner surface S1 of the current collection terminal 30 and the laminated connection portion W are usually joined to each other (fixed to each other).

[0030] (4) Laminating film The laminate film in this disclosure houses an electrode body and a plurality of current-collecting tabs. In Figure 2(b), the laminate film 40 covers the electrode body 10 and the plurality of current-collecting tabs 20. As shown in Figures 2(b) and (c), the laminate film 40 covers a portion of each side surface S3 to S6 of the current-collecting terminal 30. As shown in Figure 2(c), the laminate film 40 is arranged on each of the side surfaces S3 to S6. Each side surface and the laminate film may be in direct contact, or they may be arranged via other components (for example, a resin layer to improve adhesion). On the other hand, as shown in Figure 1, a seal portion 41 formed by fusing the laminate films 40 together is arranged along the opposing direction D1 of the electrode body 10 and the current-collecting terminal 30.

[0031] 2. Battery components The battery in this disclosure comprises at least an electrode body, a current collector tab, a current collector terminal, and a laminate film.

[0032] The electrode body in this disclosure typically comprises a power generation unit having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector in this order in the thickness direction. The electrode body typically has multiple power generation units stacked in the thickness direction. For example, the electrode body 10 shown in Figure 9 has multiple power generation units U stacked in the thickness direction (direction D3). Each power generation unit U has a positive electrode current collector 4, a positive electrode active material layer 1, an electrolyte layer 3, a negative electrode active material layer 2, and a negative electrode current collector 5 in this order in the thickness direction (direction D3). Also, adjacent power generation units U share one negative electrode current collector 5.

[0033] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of positive electrode active materials include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of oxide active materials include O2. Examples of conductive materials include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte (electrolyte solution). The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Examples of binders include rubber-based binders and fluoride-based binders.

[0034] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of negative electrode active materials include metallic active materials such as Li and Si, carbon active materials such as graphite, and Li4Ti5O 12 Examples of oxide active materials include the following. The conductive material, electrolyte, and binder are the same as described above. The electrolyte layer is placed between the positive electrode active material layer and the negative electrode active material layer and contains at least an electrolyte. The electrolyte may be a solid electrolyte or a liquid electrolyte. The electrolyte is the same as described above. The electrolyte layer may have a separator.

[0035] The positive electrode current collector collects current from the positive electrode active material layer. Examples of materials for the positive electrode current collector include metals such as aluminum, stainless steel (SUS), and nickel. The positive electrode current collector can take the form of a foil. The negative electrode current collector collects current from the negative electrode active material layer. Examples of materials for the negative electrode current collector include metals such as copper, stainless steel (SUS), and nickel. The negative electrode current collector can take the form of a foil.

[0036] The battery in this disclosure has a positive electrode tab and a negative electrode tab as current collecting tabs. As shown in Figure 9, the positive electrode tab 4t is on the side portion S of the electrode body 10. 10 The positive electrode tab 4t extends in a direction intersecting the stacking direction (direction D3) of the electrode body 10. Also, as shown in Figure 9, the positive electrode tab 4t may be formed continuously from the positive electrode active material layer 1. When observed from the stacking direction (direction D3) of the electrode body 10, the positive electrode tab 4t is positioned so as not to overlap with the positive electrode active material layer 1. Also, in Figure 9, the negative electrode tab 5t extends from the side of the electrode body 10 in a direction intersecting the stacking direction (direction D3) of the electrode body 10. Details of the negative electrode tab are the same as those of the positive electrode tab, so they are omitted here. As shown in Figure 9, the positive electrode tab 4t may extend from one side of the electrode body 10, and the negative electrode tab 5t may extend from the other side of the electrode body 10 (double-tab structure). On the other hand, although not specifically shown, the positive electrode tab and the negative electrode tab may extend from the same side of the electrode body (single-tab structure).

[0037] The current collector terminal in this disclosure is electrically connected to the current collector tab in the electrode body. The shape of the current collector terminal can be, for example, a plate shape. The material of the current collector terminal can be, for example, a metal such as Al or SUS.

[0038] The laminate film in this disclosure has at least a structure in which a heat-sealable layer and a metal layer are laminated. The laminate film may also have the heat-sealable layer, metal layer and resin layer in this order along the thickness direction. Examples of materials for the heat-sealable layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys and stainless steel. Examples of materials for the resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the heat-sealable layer is, for example, 40 μm to 100 μm. The thickness of the metal layer is, for example, 30 μm to 60 μm. The thickness of the resin layer is, for example, 20 μm to 60 μm. The thickness of the laminate film is, for example, 80 μm to 250 μm.

[0039] The battery in this disclosure is typically a lithium-ion secondary battery. Applications of the battery include, for example, powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferable for the battery to be used as a power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). Furthermore, the battery in this disclosure may be used as a power source for mobile devices other than vehicles (e.g., railways, ships, aircraft), or as a power source for electrical products such as information processing devices.

[0040] 3. Battery manufacturing method The method for manufacturing a battery in this disclosure is not particularly limited as long as it is a method that can manufacture the battery described above. Figure 10 is a schematic perspective view illustrating the method for manufacturing a battery in this disclosure. First, as shown in Figure 10(a), negative electrode active material layers 2 are formed on both sides of the negative electrode current collector 5. One method for forming the negative electrode active material layers is to apply a slurry containing the material for the negative electrode active material layer onto the negative electrode current collector and dry it. Next, as shown in Figure 10(b), an electrolyte layer (not shown), a positive electrode active material layer (not shown), and a positive electrode current collector 4 are arranged on the two negative electrode active material layers 2, respectively, to obtain a laminate α.

[0041] Subsequently, as shown in Figure 10(c), multiple laminates α are stacked in the stacking direction D L The materials are stacked to create a laminated body β. Next, as shown in Figure 10(d), the tip of the positive electrode tab 4t is joined to create a laminated connection part W, and the main surface of the laminated connection part W is joined to the inner surface S1 of the current collector terminal 30. Methods for creating the laminated connection part W include, for example, welding methods such as laser welding and electron beam welding, methods using conductive paste, and methods using solder. The method for joining the main surface of the laminated connection part W to the inner surface S1 of the current collector terminal 30 is the same as the method for creating the laminated connection part W. Next, as shown in Figure 10(e), the normal direction of the inner surface S1 and outer surface S2 of the current collector terminal 30 is the stacking direction D. L The current collection terminal 30 is rotated so that it is perpendicular to the direction. Then, the same process is performed on the negative electrode tab (not shown), and the resulting components are covered with a single laminate film so that a portion of the two opposing current collection terminals (at least the outer surface of each) is exposed, thereby obtaining a battery.

[0042] B. Battery Olive Figure 11 is a schematic perspective view illustrating a battery module in this disclosure. The battery module 200 shown in Figure 11 has multiple batteries 100 arranged in the stacking direction D of the electrode bodies. L It is stacked on top of each other.

[0043] According to this disclosure, by using the battery described in "A. Battery" above, a battery module is obtained in which stress is less likely to occur at the joint between the current collection terminals and current collection tabs, even when adjacent current collection terminals are joined together.

[0044] The battery module in this disclosure preferably has three or more batteries. Three batteries stacked in a continuous manner are referred to as battery A, battery B, and battery C, respectively. For example, the Nth battery from the top (N≧1) can be called battery A, the battery directly below it can be called battery B, and the battery directly below battery B can be called battery C.

[0045] For example, among the multiple batteries 100 shown in Figure 11, the uppermost battery 100 is designated as battery A, the battery 100 directly below it is designated as battery B, and the battery 100 directly below battery B is designated as battery C. In Figure 11, the first protrusion 32a of battery A, the first protrusion 32a of battery B, and the first protrusion 32a of battery C are aligned in the stacking direction D of the electrode bodies. L In a plan view, they are arranged so that at least a portion of each overlaps. Similarly, in Figure 11, the second protrusion 32b of battery A, the second protrusion 32b of battery B, and the second protrusion 32b of battery C are in the stacking direction D of the electrode bodies. L In a plan view, they are arranged so that at least a portion of each overlaps.

[0046] In Figure 11, battery B (the second battery 100 from the top) is used as the reference. It is preferable that the first protrusion 32a of battery B is joined to the first protrusion 32a of battery A (the topmost battery 100), but not joined to the first protrusion 32a of battery C (the third battery 100 from the top). Furthermore, it is preferable that the second protrusion 32b of battery B is not joined to the second protrusion 32b of battery A (the topmost battery 100), but is joined to the second protrusion 32b of battery C (the third battery 100 from the top). Thus, the stacking direction D of the electrode bodies L In this configuration, by satisfying the following conditions, deformation of the current collection terminal can be effectively suppressed: (i) alternating the joints of adjacent first protrusions 32a with the non-joints of adjacent first protrusions 32a; (ii) alternating the joints of adjacent second protrusions 32b with the non-joints of adjacent second protrusions 32b; and (iii) shifting the period of the joints and non-joints in the first protrusions 32a with the period of the joints and non-joints in the second protrusions 32b.

[0047] Furthermore, in Figure 11, the stacking direction D of the electrode body is shown. L In this configuration, multiple first current collection terminals 30A are arranged to overlap. In this case, each battery 100 is connected in parallel. On the other hand, as shown in Figure 12, the stacking direction D of the electrode bodies LIn this configuration, multiple first current collection terminals 30A and multiple second current collection terminals 30B may be arranged in an overlapping manner. In this case, the battery group connected by multiple first current collection terminals 30A and the battery group connected by multiple second current collection terminals 30B are connected in series.

[0048] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Explanation of symbols]

[0049] 1...Cathode active material layer 2...Negative electrode active material layer 3...Electrolyte layer 4...Positive electrode current collector 5...Negative electrode current collector 10...Electrode body 20... Current collection tab 30...Current collector terminal 40... Laminating film 100...battery 200... Battery Module

Claims

[Claim 1] Electrode body and Multiple current-collecting tabs extending from the side surface of the electrode body, The current collection terminal connected to the aforementioned multiple current collection tabs, A laminate film that houses the electrode body and the plurality of current collecting tabs, A battery having, The current collector tab has a base portion which is the end on the electrode body side, a connecting portion for connecting to the current collector terminal, and an intermediate portion connecting the base portion and the connecting portion. Each of the plurality of current-collecting tabs has a laminated connection portion which is stacked in the thickness direction, The current collection terminal has an inner surface facing the side surface of the electrode body and a side surface arranged along the outer edge of the inner surface, The laminate film is placed on the side surface of the current collection terminal. The main surface of the laminated connection portion is joined to the inner surface. A battery in which, in a plan view in the stacking direction of the electrode bodies, the current collector terminal has a base portion including a first end portion corresponding to the inner surface position and a second end portion facing the first end portion, and a projection portion projecting from the base portion toward the side opposite to the electrode bodies.

Images