Battery and battery module
Patent Information
- Application Number
- JP2024114628
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2025-01-30
- Estimated Expiration
- 2042-06-27
AI Technical Summary
When stacking multiple batteries, stress is generated at the joints of the current collector terminals and current collector tabs, leading to reduced bonding properties and potential damage.
A battery design featuring a current collector terminal with a laminated connection portion and protrusions, which disperses stress and reduces positional change during stacking, using a laminate film to house the electrode body and current collector tabs.
The design minimizes stress at the joints between the current collector terminal and tab, enhancing durability and bonding properties, even when batteries are stacked.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present disclosure relates to batteries and battery modules. [Background technology]
[0002] A battery such as a lithium ion secondary battery usually includes an electrode body 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 body is sealed by an exterior body. Electricity generated in the electrode body is led from the inside of the exterior body to the outside by a current collecting terminal. For example, Patent Document 1 discloses a stacked or stacked / folded electrode assembly having a positive electrode / separator / negative electrode structure. Also, FIG. 2 of Patent Document 1 discloses that a plurality of tabs (e.g., positive electrode tabs 40) are joined in a dense form and connected to a lead (e.g., positive electrode lead 60). Furthermore, Patent Document 1 discloses the use of a laminate sheet (laminate film) as the exterior body. Similarly, Patent Documents 2 and 3 also disclose the use of a laminate film as the exterior body. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent No. 5550805 [Patent Document 2] JP 2011-108623 A [Patent Document 3] JP 2020-115423 A Summary of the Invention [Problem to be solved by the invention]
[0004] When multiple batteries (battery cells) are stacked and adjacent collector terminals are joined, stress is generated at the joint between the collector terminal and the collector tab, which may reduce the bond between the collector terminal and the collector tab or cause damage to the collector tab.
[0005] The present disclosure has been made in consideration of the above-mentioned situation, and has as its main object to provide a battery in which stress is less likely to occur at the joints between the current collecting terminals and the current collecting tabs, even when multiple batteries are stacked and adjacent current collecting terminals are joined. [Means for solving the problem]
[0006] [1] A battery having an electrode body, a plurality of current collecting tabs extending from a side portion of the electrode body, a current collecting terminal connected to the plurality of current collecting tabs, and a laminate film that houses the electrode body and the plurality of current collecting tabs, wherein the current collecting tab has a root portion which is an end portion on the electrode body side, a connection portion for connecting to the current collecting terminal, and an intermediate portion that connects the root portion and the connection portion, and each of the connection portions of the plurality of current collecting tabs has a stacked connection portion in which the connection portions are stacked in a thickness direction, the current collecting terminal has an inner surface facing the side portion of the electrode body and a side surface arranged along the outer edge of the inner surface, the laminate film is arranged on the side of the current collecting terminal and a main surface of the stacking connection portion is joined to the inner surface, and in a planar view in the stacking direction of the electrode body, the current collecting terminal has a first end corresponding to the position of the inner surface and a base including a second end facing the first end, and a protrusion protruding from the base to the opposite side 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 portions have a curved structure in which parts of the intermediate portions face each other.
[0008] [3] The battery according to [1] or [2], wherein the current collecting terminal has a first protrusion and a second protrusion as the protrusion, and when, in a plan view in the stacking direction of the electrode body, a facing direction of the electrode body and the current collecting terminal is defined as D1, a direction perpendicular to D1 is defined as D2, and an axis that is parallel to D1 and passes through a midpoint of the current collecting terminal at D2 is defined as AX, the first protrusion is disposed in one area of the current collecting terminal defined by AX, and the second protrusion is disposed in the other area of the current collecting terminal defined by AX.
[0009] [4] A battery module in which a plurality of batteries are stacked, the batteries being the battery described in any one of [1] to [3].
[0010] [5] a battery module in which a plurality of batteries are stacked, the batteries being the battery described in [3]; the battery module has battery A, battery B, and battery C as the batteries, the battery A, the battery B, and the battery C being stacked continuously, the first protrusion of battery A, the first protrusion of battery B, and the first protrusion of battery C being arranged so as to overlap at least partially when viewed in a plane in the stacking direction of the electrode body, the second protrusion of battery A, the second protrusion of battery B, and the second protrusion of battery C being arranged so as to overlap at least partially when viewed in a plane in the stacking direction of the electrode body, the first protrusion of battery B being joined to the first protrusion of battery A and not joined to the first protrusion of battery C, and the second protrusion of battery B being not joined to the second protrusion of battery A and joined to the second protrusion of battery C. Effect of the Invention
[0011] The present disclosure has an effect of providing a battery in which stress is unlikely to occur at the joint between the current collecting terminal and the current collecting tab, even when a plurality of batteries are stacked. [Brief description of the drawings]
[0012] [Figure 1] FIG. 1 is a schematic perspective view illustrating a battery according to the present disclosure. [Diagram 2] 1A and 1B are schematic plan and side views illustrating a battery according to the present disclosure. [Diagram 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 2 is a schematic plan view illustrating a current collecting terminal and its surroundings in the present disclosure. [Diagram 5] 1A and 1B are a schematic perspective view and a schematic side view illustrating a conventional battery. [Figure 6] 1A and 1B are a schematic perspective view and a schematic side view illustrating a battery according to the present disclosure. [Figure 7] FIG. 2 is a schematic plan view illustrating a current collecting terminal according to the present disclosure. [Figure 8] FIG. 2 is a schematic perspective view illustrating a current collecting terminal according to the present disclosure. [Figure 9] 1 is a schematic cross-sectional view illustrating an electrode body according to the present disclosure. [Figure 10] 1 is a schematic perspective view illustrating a method for manufacturing a battery according to the present disclosure. [Figure 11] FIG. 1 is a schematic perspective view illustrating a battery module according to the present disclosure. [Figure 12] FIG. 1 is a schematic perspective view illustrating a battery module according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The battery and battery module of the present disclosure will be described in detail below with reference to the drawings. Each of the drawings shown below is a schematic illustration, and the size and shape of each part are appropriately exaggerated to facilitate understanding. Furthermore, hatching of each part may be omitted as appropriate.
[0014] A.Battery FIG. 1 is a schematic perspective view illustrating a battery in the present disclosure. FIGS. 2(a) and 2(b) are schematic plan views illustrating a battery in the present disclosure, and FIG. 2(c) is a schematic side view illustrating a battery in the present disclosure. As shown in FIGS. 1 and 2, a battery 100 includes an electrode body 10 and a side portion S of the electrode body 10. 10 The electrode body 10 has a plurality of current collecting tabs 20 extending therefrom, a current collecting terminal 30 (a first current collecting terminal 30A and a second current collecting terminal 30B) connected to the plurality of current collecting tabs 20, and a laminate film 40 that houses the electrode body 10 and the plurality of current collecting tabs 20.
[0015] Fig. 3 is a cross-sectional view taken along line AA in Fig. 2. As shown in Fig. 3, the current collecting tab 20 has a root portion X which is the end portion on the electrode body 10 side, a connection portion Y for connecting to the current collecting terminal 30, and an intermediate portion Z which connects the root portion X and the connection portion Y. The current collecting tabs 20 also have a stacked connection portion W in which the connection portions Y are stacked in the thickness direction (the vertical direction in Fig. 3). The current collecting terminal 30 is connected to the side portion S of the electrode body 10. 10 2(c), a laminate film 40 is disposed on the four side surfaces S3 to S6. As shown in FIG. 3, the main surface of the laminated connection part W is joined to the inner surface S1 of the current collecting terminal 30.
[0016] 4 is a schematic plan view illustrating a current collecting terminal and its surroundings in the present disclosure. As shown in FIG. 4, the current collecting terminal 30 has a base 31 including a first end T1 corresponding to the position of the inner surface S1 and a second end T2 facing the first end T1, and a protruding portion 32 protruding from the base 31 to the opposite side to the electrode body 10.
[0017] According to the present disclosure, by using a predetermined current collecting terminal, even when a plurality of batteries are stacked and adjacent current collecting terminals are joined, a battery is obtained in which stress is unlikely to occur at the joint between the current collecting terminal and the current collecting tab. Here, FIG. 5(a) is a schematic perspective view illustrating a conventional battery, and FIG. 5(b) is a schematic side view of the battery shown in FIG. 5(a) observed from the bottom of the drawing. Also, FIG. 6(a) is a schematic perspective view illustrating a battery in the present disclosure, and FIG. 6(b) is a schematic side view of the battery shown in FIG. 6(a) observed from the bottom of the drawing. As shown in FIGS. 5(a) and (b), in the conventional battery, the joint between the current collecting terminal 30 and the current collecting tab 20 was disposed on the main surface of the current collecting terminal 30 (the surface whose normal direction coincides with the thickness direction). Since the thickness of the current collecting terminal 30 is thin, the position of the current collecting terminal 30 in the thickness direction changes significantly when a plurality of batteries are stacked. As a result, a large stress is generated at the joint between the current collecting terminal 30 and the current collecting tab 20, and the joint between the current collecting terminal and the current collecting tab may be reduced, or the current collecting tab may be damaged. In response to this, as shown in Figs. 6(a) and 6(b), in the present disclosure, a current collecting terminal 30 having an inner surface S1 with which the main surface of the stacked joint W can make surface contact is used. That is, since the thickness of the current collecting terminal 30 is large, the position change of the current collecting terminal 30 in the thickness direction is small when stacking multiple batteries. As a result, it is possible to suppress the generation of a large stress at the joint between the current collecting terminal 30 and the current collecting tab 20. Furthermore, since the current collecting terminal 30 has a protrusion 32, there is an advantage that the position change of the current collecting terminal 30 in the thickness direction is small when stacking multiple batteries compared to when the current collecting terminal 30 does not have the protrusion 32. In particular, as described later, when multiple current collecting tabs 20 have a curved structure, even if stress is generated at the joint between the current collecting terminal 30 and the current collecting tab 20, the curved structure makes it easier to disperse the stress.
[0018] 1. Battery configuration The battery of the present disclosure has an electrode body, a plurality of current collecting tabs extending from a side portion of the electrode body, a current collecting terminal connected to the plurality of current collecting tabs, and a laminate film that houses the electrode body and the plurality of current collecting tabs.
[0019] (1) Electrode body The electrode body in the present disclosure usually includes 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 it is preferable that the electrode body has, for example, a top surface portion, a bottom surface portion facing the top surface portion, and four side surfaces connecting the top surface portion and the bottom surface portion. The shape of the top surface portion is not particularly limited, but examples thereof include quadrangles such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram. The shape of the top surface portion may be a polygon other than a quadrangle, or may be a shape having a curve such as a circle. The shape of the bottom surface portion is the same as that of the top surface portion. The shape of the side surface portion is not particularly limited, but examples thereof include quadrangles such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram.
[0020] (2) Multiple current collecting tabs In the present disclosure, the multiple current collecting tabs are arranged to extend from the side surface of the electrode assembly. The "side surface of the electrode assembly" refers to a portion that constitutes the electrode assembly and whose normal direction intersects with the stacking direction of the electrode assembly. For example, in FIG. 3, the side surface S of the electrode assembly 10 10 The normal direction (vertical direction in the drawing) is perpendicular to the stacking direction (horizontal direction in the drawing) of the electrode body 10. Moreover, the "stacking direction of the electrode body" refers to the thickness direction of each layer constituting the electrode body.
[0021] As shown in FIG. 3, the current collecting tab 20 has a root portion X which is an end portion on the electrode body 10 side, a connection portion Y for connecting to the current collecting terminal 30, and an intermediate portion Z which connects the root portion X and the connection portion Y. The root portion X is an end portion (boundary portion) of the current collecting tab 20 on the electrode body 10 side. The connection portion Y is a portion for connecting to the current collecting terminal 30, and is a portion which constitutes a stacked connection portion W described later. The intermediate portion Z is a portion which connects the root portion X and the connection portion Y. In the present disclosure, the multiple current collecting tabs have a stacked connection portion in which the respective connection portions are stacked in the thickness direction. In FIG. 3, each connection portion Y of the multiple current collecting tabs 20 is stacked in the thickness direction of the current collecting tab 20, thereby forming the stacked connection portion W. In the stacked connection portion W, each connection portion Y is joined to each other (fixed to each other).
[0022] As shown in FIG. 3, in a cross-sectional view of the electrode body 10 in the stacking direction, the intermediate portion Z preferably has a curved structure (area indicated by a broken line) in which parts of the intermediate portion Z are curved to face each other. In FIG. 3, the intermediate portion Z of the rightmost current collecting tab 20 among the multiple current collecting tabs 20 does not have the above-mentioned curved structure because parts of the intermediate portion Z do not face each other, but the intermediate portions Z of the other multiple current collecting tabs 20 all have a curved structure. In this way, it is preferable that the intermediate portion Z of at least one current collecting tab 20 among the multiple current collecting tabs 20 has a curved structure. In the curved structure, parts of the opposing intermediate portions Z may be arranged to be in direct contact with each other, or may be arranged with a space therebetween. In addition, as shown in FIG. 3, the intermediate portions Z of the multiple current collecting tabs 20 are preferably curved in a U-shape.
[0023] (3) Current collector terminal The current collecting terminal in the present disclosure has an inner surface facing the side portion 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, and examples thereof include quadrangles such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The number of sides is, for example, multiple. The number of sides depends on, for example, the shape of the outer edge of the inner surface. For example, when the shape of the outer edge of the inner surface is a quadrangle, the current collecting terminal may have four sides. The current collecting terminal may 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 protrusion described later may each have an outer surface facing the inner surface. The inner surface, the side surface, and the outer surface may each be flat or curved.
[0024] As shown in FIG. 4, the current collecting terminal 30 has a base portion 31 and a protruding portion 32 in a plan view. The base 31 includes a first end T1 corresponding to the position of the inner surface S1 and a second end T2 opposite to the first end T1. In FIG. 214, the opposing direction of the electrode body 10 and the current collecting terminal 30 is designated as D1, and the direction perpendicular to D1 is designated as D2. The base 31 corresponds to the portion from the position of the first end T1 to the position of the second end T2 in the direction D1. The base 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. The shape of the base 31 may be, for example, a rectangular parallelepiped. Meanwhile, the protruding portion 32 is a portion that protrudes from the base 31 to the opposite side to the electrode body 10 in the direction D1. In FIG. 4, the protruding portion 32 is located on the outer surface S 22 The third end T3 is located outside the second end T2 in the direction D1 (on the opposite side to the electrode body 10). The shape of the protrusion 32 is, for example, a rectangular parallelepiped. The protrusion 32 is preferably formed continuously from the base 31.
[0025] The current collecting terminal in the present disclosure may have a plurality of protrusions. In FIG. 4, the current collecting terminal 30 has a first protrusion 32a and a second protrusion 32b as the protrusions 32. As shown in FIG. 4, an axis AX is parallel to the direction D1 and passes through the midpoint C of the current collecting terminal 30 in the direction D2. It is preferable that the first protrusion 32a is arranged in one region of the current collecting terminal 30 defined by the axis AX, and the second protrusion 32b is arranged in the other region of the current collecting terminal 30 defined by the axis AX. As shown in FIG. 4, the current collecting terminal 30 preferably has a U-shape. Also, as shown in FIG. 7, the current collecting terminal 30 may have one protrusion 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 L1, the length of the current collecting terminal 30 in the direction D2 is L2, and the length of the current collecting terminal 30 in the direction D3 (the direction perpendicular to both D1 and D2) is L3. 11 The length of the protrusion in the direction D1 is L 12 Let us assume that L 11 L for 12Percentage of (L 12 / L 11 ) is, for example, 0.5 or more and 5 or less, and may be 1 or more and 3 or less. 11 and L 12 are, for example, 0.5 cm or more and 5 cm or less, respectively. L2 may be larger than L1. The ratio of L2 to L1 (L2 / L1) is, for example, 2 or more, 5 or more, or 10 or more. L2 may be larger than L3. The ratio of L2 to L3 (L2 / L3) is, for example, 5 or more, 10 or more, or 50 or more. L1 may be larger than L3. The ratio of L1 to L3 (L1 / L3) is, for example, 2 or more, 5 or more, or 10 or more.
[0027] Although not shown in the figure, the length of the electrode body in the direction D1 is L X The length of the electrode body in the direction D2 is L Y The length of the electrode body in the direction D3 is L Z Let us assume that L X The ratio of L1 to L X ) is not particularly limited. Y The ratio of L2 to L Y ) is, for example, 0.8 or more, may be 0.9 or more, or may be 0.95 or more. L2 / L Y For example, L is less than or equal to 1.0. Z The ratio of L3 to L Z ) is, for example, 0.8 or more, may be 0.9 or more, or may be 0.95 or more. Z is, for example, less than or equal to 1.0.
[0028] When the battery is viewed from the side of the current collector terminal, the inner surface of the current collector terminal and the side surface of the electrode body are arranged to overlap. The area where the inner surface of the current collector terminal and the side surface of the electrode body overlap is called the overlapping area. The area S of the side surface of the electrode body A The area of the overlapping region S B The ratio (S B / S A) is, for example, 80% or more, may be 90% or more, or may be 95% or more. B / S A is less than 100%.
[0029] 3, the main surface of the laminate connection part W is joined to the inner surface S1 of the current collecting terminal 30. The "main surface of the laminate connection part W" refers to a surface that constitutes the laminate connection part W and whose normal direction coincides with the thickness direction of the connection part Y. The main surface of the laminate connection part W may be joined to the inner surface S1 in direct contact therewith, or may be joined via another member (e.g., a conductive layer). The inner surface S1 of the current collecting terminal 30 and the laminate connection part W are usually joined to each other (fixed to each other).
[0030] (4) Laminate film The laminate film in the present disclosure houses the electrode body and the multiple current collecting tabs. In FIG. 2(b), the laminate film 40 covers the electrode body 10 and the multiple current collecting tabs 20. As shown in FIGS. 2(b) and 2(c), the laminate film 40 covers a part of each of the side surfaces S3 to S6 of the current collecting terminal 30. As shown in FIG. 2(c), the laminate film 40 is disposed on each of the side surfaces S3 to S6. The side surfaces and the laminate film may be in direct contact with each other, or may be disposed via another member (for example, a resin layer for improving adhesion). Meanwhile, as shown in FIG. 1, a seal portion 41 in which the laminate films 40 are fused together is disposed along the opposing direction D1 of the electrode body 10 and the current collecting terminal 30.
[0031] 2. Battery components The battery according to the present disclosure includes at least an electrode body, a current collecting tab, a current collecting terminal, and a laminate film.
[0032] The electrode body in the present disclosure usually includes a generating 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 usually has a plurality of generating units stacked in the thickness direction. For example, the electrode body 10 shown in FIG. 9 has a plurality of generating units U stacked in the thickness direction (direction D3). Each generating 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). Adjacent generating 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. The positive electrode active material is, for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of the active material include oxide active materials such as O2. Examples of the conductive material include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte (electrolytic 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 the binder 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 the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, Li4Ti5O 12 Examples of oxide active materials include oxide active materials such as . The conductive material, electrolyte, and binder are the same as those described above. The electrolyte layer is disposed 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 those described above. The electrolyte layer may have a separator.
[0035] The positive electrode current collector collects the current of the positive electrode active material layer. Examples of the material of the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of the shape of the positive electrode current collector include a foil shape. The negative electrode current collector collects the current of the negative electrode active material layer. Examples of the material of the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include a foil shape.
[0036] The battery of the present disclosure has a positive electrode tab and a negative electrode tab as current collecting tabs. As shown in FIG. 9, the positive electrode tab 4t is connected to the side surface S of the electrode assembly 10. 10 From the electrode assembly 10, the positive electrode tab 4t extends in a direction intersecting the stacking direction (direction D3) of the electrode assembly 10. As shown in FIG. 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 assembly 10, the positive electrode tab 4t is disposed at a position not overlapping with the positive electrode active material layer 1. In FIG. 9, the negative electrode tab 5t extends from the side surface of the electrode assembly 10 in a direction intersecting the stacking direction (direction D3) of the electrode assembly 10. Details of the negative electrode tab are similar to those of the positive electrode tab, so they will not be described here. As shown in FIG. 9, the positive electrode tab 4t may extend from one side surface of the electrode assembly 10, and the negative electrode tab 5t may extend from the other side surface of the electrode assembly 10 (double tab structure). On the other hand, although not particularly shown, the positive electrode tab and the negative electrode tab may extend from the same side surface of the electrode assembly (single tab structure).
[0037] The current collecting terminal in the present disclosure is electrically connected to a current collecting tab of the electrode body. The shape of the current collecting terminal may be, for example, a plate shape. The material of the current collecting terminal may be, for example, a metal such as Al or SUS.
[0038] The laminate film in the present disclosure has at least a structure in which a heat-sealing layer and a metal layer are laminated. The laminate film may have a heat-sealing layer, a metal layer, and a resin layer in this order along the thickness direction. Examples of the material of the heat-sealing layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of the material of the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of the material of the resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the heat-sealing layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.
[0039] The battery in the present disclosure is typically a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, the battery is preferably used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for moving objects other than vehicles (e.g., railways, ships, and aircraft), and may also be used as a power source for electrical products such as information processing devices.
[0040] 3. Battery manufacturing method The method for manufacturing a battery in the present disclosure is not particularly limited as long as it can manufacture the above-mentioned battery. FIG. 10 is a schematic perspective view illustrating a method for manufacturing a battery in the present disclosure. First, as shown in FIG. 10(a), a negative electrode active material layer 2 is formed on each of both sides of a negative electrode current collector 5. As a method for forming the negative electrode active material layer, for example, a method of applying a slurry containing a material for the negative electrode active material layer onto the negative electrode current collector and drying it can be mentioned. Next, as shown in FIG. 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] Then, as shown in FIG. 10(c), the plurality of laminates α are stacked in the stacking direction D L 10(d), the tip of the positive electrode tab 4t is joined to form a laminated joint W, and the main surface of the laminated joint W is joined to the inner surface S1 of the current collecting terminal 30. Examples of a method for forming the laminated joint W include a method using welding such as laser welding and electron beam welding, a method using a conductive paste, and a method using solder. The method for joining the main surface of the laminated joint W to the inner surface S1 of the current collecting terminal 30 is the same as the method for forming the laminated joint W. Next, as shown in FIG. 10(e), the normal direction of the inner surface S1 and the outer surface S2 of the current collecting terminal 30 is aligned in the stacking direction D. L The current collecting terminal 30 is rotated so that it is perpendicular to the current collecting terminal 30. The negative electrode tab (not shown) is then subjected to the same treatment, and the obtained member is covered with a laminate film so that a portion of the two opposing current collecting terminals (at least the outer surfaces of each) is exposed, thereby obtaining a battery.
[0042] B. Battery module 11 is a schematic perspective view illustrating a battery module in the present disclosure. The battery module 200 shown in FIG. 11 includes a plurality of batteries 100 arranged in a stacking direction D of the electrode assembly. L The layers are stacked on top of each other.
[0043] According to the present 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 joints between the current collecting terminals and the current collecting tabs, even when adjacent current collecting terminals are joined.
[0044] The battery module in the present disclosure preferably has three or more batteries. The three batteries stacked in series are referred to as battery A, battery B, and battery C, respectively. For example, the Nth (N≧1) battery from the top can be battery A, the battery directly below it can be battery B, and the battery directly below battery B can be battery C.
[0045] For example, among the multiple batteries 100 shown in Fig. 11, the uppermost battery 100 is battery A, the battery 100 immediately below it is battery B, and the battery 100 immediately below battery B is battery C. In Fig. 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 assembly. L 11, the second protrusions 32b of the battery A, the second protrusions 32b of the battery B, and the second protrusions 32b of the battery C are arranged so as to overlap at least partially with each other in the stacking direction D of the electrode assembly. L are arranged so as to overlap at least partially with each other in a plan view.
[0046] In FIG. 11, battery B (the second battery 100 from the top) is used as a 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) and is 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) and is joined to the second protrusion 32b of battery C (the third battery 100 from the top). In this way, the stacking direction D of the electrode body L In this embodiment, deformation of the current collecting terminal can be effectively suppressed by: (i) arranging the joints of adjacent first protrusions 32a alternately with the non-joints of adjacent first protrusions 32a; (ii) arranging the joints of adjacent second protrusions 32b alternately 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 from the period of the joints and non-joints in the second protrusions 32b.
[0047] In addition, in FIG. 11, the stacking direction D of the electrode body L In this case, the first current collecting terminals 30A are arranged so as to overlap each other. In this case, the batteries 100 are connected in parallel. On the other hand, as shown in FIG. LIn the battery pack, the first current collecting terminals 30A and the second current collecting terminals 30B may be arranged to overlap each other. In this case, the battery group joined by the first current collecting terminals 30A and the battery group joined by the second current collecting terminals 30B are connected in series.
[0048] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included in the technical scope of the present 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 collecting tab 30...Current collector terminal 40...Laminate film 100...battery 200…Battery module
Claims
1. An electrode body; a plurality of current collecting tabs extending from a side portion of the electrode body; a current collecting terminal connected to the plurality of current collecting tabs; a laminate film that houses the electrode body and the multiple current collecting tabs; A battery having the current collecting tab has a root portion which is an end portion on the electrode body side, a connection portion for connecting to the current collecting terminal, and an intermediate portion connecting the root portion and the connection portion, The connection portions of each of the current collecting tabs have a laminated connection portion in which the connection portions are laminated in a thickness direction, the current collecting terminal has an inner surface facing the side surface portion of the electrode body and a side surface disposed along an outer edge of the inner surface, The laminate film is disposed on the side surface of the current collecting terminal, A main surface of the laminated joint portion is joined to the inner surface, In a plan view in a stacking direction of the electrode assembly, the current collecting terminal has a protrusion that protrudes to an opposite side to the electrode assembly.
2. A battery as described in claim 1, wherein, when viewed in a cross-sectional view in the stacking direction of the electrode body, the intermediate portions have a curved structure in which parts of the intermediate portions face each other.
3. The current collecting terminal has a first protrusion and a second protrusion as the protrusion, In a plan view of the stacking direction of the electrode body, a facing direction of the electrode body and the current collecting terminal is defined as D1, a direction perpendicular to D1 is defined as D2, and an axis that is parallel to D1 and passes through a midpoint of the current collecting terminal at D2 is defined as AX. The first protrusion is disposed in one region of the current collecting terminal defined by the AX, The battery according to claim 1 or 2, wherein the second protrusion is disposed in the other region of the current collector terminal partitioned by the AX.
4. A battery module comprising a plurality of stacked batteries, A battery module, wherein the battery is the battery according to claim 1 or 2.
5. A battery module in which a plurality of batteries are stacked, The battery is the battery according to claim 3 , the battery module includes, as the batteries, a battery A, a battery B, and a battery C; the battery A, the battery B, and the battery C are stacked in series, the first protruding portion of the battery A, the first protruding portion of the battery B, and the first protruding portion of the battery C are arranged so as to at least partially overlap each other in a plan view in the stacking direction of the electrode body, the second protruding portion of the battery A, the second protruding portion of the battery B, and the second protruding portion of the battery C are arranged so as to at least partially overlap each other in a plan view in the stacking direction of the electrode body, the first protruding portion of the battery B is joined to the first protruding portion of the battery A and is not joined to the first protruding portion of the battery C; A battery module, wherein the second protrusion of the battery B is not joined to the second protrusion of the battery A and is joined to the second protrusion of the battery C.