Batteries and Battery Modules
The battery design addresses stress at collector joints by using a current collecting terminal with stacked connections and protrusions, ensuring bond strength in stacked batteries.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2026-03-10
AI Technical Summary
Stress occurs at the joints between the collector terminal and the collector tab when multiple batteries are stacked, leading to reduced bond strength and potential damage.
A battery design with current collecting tabs having a base, connection, and intermediate portions, and a current collecting terminal with stacked connection portions and protrusions, where the laminate film is arranged on the terminal's inner surface, reducing stress by allowing for surface contact and stress dispersion.
The design minimizes stress at the joint between the current collecting terminal and tab, maintaining bond integrity 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] Batteries such as lithium-ion secondary batteries typically include 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 in an exterior case. Electricity generated in the electrode assembly is conducted from the inside of the exterior case to the outside via 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. Furthermore, FIG. 2 of Patent Document 1 discloses that multiple tabs (e.g., positive electrode tabs 40) are closely coupled and connected to a lead (e.g., positive electrode lead 60). Patent Document 1 also discloses the use of a laminate sheet (laminate film) as the exterior case. Similarly, Patent Documents 2 and 3 also disclose the use of a laminate film as the exterior case. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent No. 5550805 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-108623 [Patent Document 3] Japanese Patent Publication No. 2020-115423 Summary of the Invention [Problem to be solved by the invention]
[0004] When stacking multiple batteries (battery cells) and joining adjacent collector terminals, stress occurs at the joint between the collector terminal and the collector tab, which can 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-described circumstances, 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 surface of the electrode body, current collecting terminals 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 tabs have a base portion that 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 base portion and the connection portion, and the connection portions of the plurality of current collecting tabs each have a stacked 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 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 surface of the current collecting terminal and a main surface of the stacking connection portion is joined to the inner surface, and in a plan view in the stacking direction of the electrode body, the current collecting terminal has a first end portion corresponding to the position of the inner surface and a base portion including a second end portion facing the first end portion, and a protrusion portion protruding from the base portion to the opposite side of 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 are curved to face each other.
[0008] [3] 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, D1 is the opposing direction of the electrode body and the current collecting terminal, D2 is a direction perpendicular to D1, and AX is an axis parallel to D1 and passing through the midpoint of the current collecting terminal at D2, the first protrusion is arranged in one area of the current collecting terminal defined by AX, and the second protrusion is arranged 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 batteries according to any one of [1] to [3].
[0010] [5] a battery module in which a plurality of batteries are stacked, the batteries being the batteries described in [3]; the battery module has battery A, battery B, and battery C as the batteries, the battery A, battery B, and 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 at least partially overlap each other in a planar view 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 at least partially overlap each other in a planar view in the stacking direction of the electrode body; the first protrusion of battery B is joined to the first protrusion of battery A but is not joined to the first protrusion of battery C; and the second protrusion of battery B is not joined to the second protrusion of battery A but is joined to the second protrusion of battery C. [Effects of the Invention]
[0011] The present disclosure has the 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 explanation of the drawings]
[0012] [Figure 1] FIG. 1 is a schematic perspective view illustrating a battery according to the present disclosure. [Figure 2] 1A and 1B are a schematic plan view and a schematic side view illustrating a battery according to the present disclosure. [Figure 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 according to the present disclosure. [Figure 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 INVENTION
[0013] The battery and battery module of the present disclosure will be described in detail below with reference to the drawings. The drawings are schematic, and the size and shape of each part are appropriately exaggerated for ease of understanding. Hatching of each part may also be omitted as appropriate.
[0014] A.Battery Fig. 1 is a schematic perspective view illustrating a battery according to the present disclosure. Fig. 2(a) and Fig. 2(b) are schematic plan views illustrating a battery according to the present disclosure, and Fig. 2(c) is a schematic side view illustrating a battery according to the present disclosure. As shown in Figs. 1 and 2, a battery 100 includes an electrode assembly 10 and a side surface S of the electrode assembly 10. 10 The electrode assembly 10 has a plurality of current collecting tabs 20 extending therefrom, current collecting terminals 30 (first current collecting terminal 30A and second current collecting terminal 30B) connected to the plurality of current collecting tabs 20, and a laminate film 40 that houses the electrode assembly 10 and the plurality of current collecting tabs 20.
[0015] 3 is a cross-sectional view taken along the line AA in FIG. 2. As shown in FIG. 3, the current collecting tab 20 has a base 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 connecting the base 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 according to 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 protrusion 32 protruding from the base 31 in the opposite direction from the electrode body 10.
[0017] According to the present disclosure, by using a predetermined current collecting terminal, even when multiple batteries are stacked and adjacent current collecting terminals are joined, stress is less likely 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) viewed from below. Also, FIG. 6(a) is a schematic perspective view illustrating a battery according to the present disclosure, and FIG. 6(b) is a schematic side view of the battery shown in FIG. 6(a) viewed from below. As shown in FIGS. 5(a) and 5(b), in conventional batteries, the joint between the current collecting terminal 30 and the current collecting tab 20 is located on the main surface of the current collecting terminal 30 (the surface whose normal direction coincides with the thickness direction). Because the current collecting terminal 30 is thin, the position of the current collecting terminal 30 in the thickness direction changes significantly when multiple batteries are stacked. As a result, large stress is generated at the joint between the current collecting terminal 30 and the current collecting tab 20, which may reduce the bond between the current collecting terminal and the current collecting tab or cause damage to the current collecting tab. In response to this, as shown in FIGS. 6( a) and 6(b), the present disclosure uses a current collecting terminal 30 having an inner surface S1 with which the main surface of the stack joint W can make surface contact. That is, because the current collecting terminal 30 is thick, the positional change of the current collecting terminal 30 in the thickness direction is small when multiple batteries are stacked. As a result, the generation of large stress at the joint between the current collecting terminal 30 and the current collecting tab 20 can be suppressed. Furthermore, the current collecting terminal 30 has a protrusion 32, which has the advantage that the positional change of the current collecting terminal 30 in the thickness direction is small when multiple batteries are stacked, compared to a case without the protrusion 32. In particular, as described below, 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 facilitates stress dispersion.
[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, current collecting terminals 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 assembly of the present disclosure typically 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 assembly is not particularly limited, but preferably includes, for example, 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 polygonal other than a quadrilateral, or may have a curved shape such as a circle. The shape of the bottom surface is similar to that 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 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) of the electrode assembly 10 is perpendicular to the stacking direction (horizontal direction in the drawing) of the electrode assembly 10. The "stacking direction of the electrode assembly" refers to the thickness direction of each layer that constitutes the electrode assembly.
[0021] 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 connection to the current collecting terminal 30, and an intermediate portion Z connecting the root portion X and the connection portion Y. The root portion X is the end (boundary portion) of the current collecting tab 20 on the electrode body 10 side. The connection portion Y is a portion for connection to the current collecting terminal 30 and is a portion that constitutes a stacked connection portion W, which will be described later. The intermediate portion Z is a portion that connects the root portion X and the connection portion Y. In the present disclosure, multiple current collecting tabs have a stacked connection portion in which their respective connection portions are stacked in the thickness direction. In FIG. 3, the connection portions Y of the multiple current collecting tabs 20 are stacked in the thickness direction of the current collecting tab 20, thereby forming the stacked connection portion W. In the stacked connection portion W, the connection portions Y are joined to each other (fixed to each other).
[0022] As shown in FIG. 3, in a cross-sectional view of the electrode assembly 10 in the stacking direction, the intermediate portions Z preferably have a curved structure (regions indicated by dashed lines) in which portions of the intermediate portions Z 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 portions of the intermediate portions Z do not face each other, but the intermediate portions Z of the other multiple current collecting tabs 20 all have a curved structure. As such, it is preferable that the intermediate portion Z of at least one of the multiple current collecting tabs 20 has a curved structure. In the curved structure, portions of the opposing intermediate portions Z may be arranged so as to be in direct contact with each other or may be arranged with a space between them. Furthermore, 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 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 outer edge of the inner surface is quadrilateral, the current collecting terminal may have four side surfaces. The current collecting terminal may also have an outer surface facing the inner surface. The inner surface typically corresponds to the surface within the area sealed by the laminate film. The outer surface typically corresponds to the surface outside the area sealed by the laminate film. The base and protrusions described below may each have an outer surface facing the inner surface. The inner surface, side surface, and 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 can be, for example, a rectangular parallelepiped. Meanwhile, the protruding portion 32 is a portion that protrudes from the base 31 in the opposite direction to the electrode body 10 in the direction D1. In FIG. 4, the protruding portion 32 is located on the outer surface S2. 22 The third end T3 is located further outward than the second end T2 in the direction D1 (on the opposite side from the electrode body 10). The shape of the protrusion 32 may be, for example, a rectangular parallelepiped. It is preferable that the protrusion 32 is formed continuously from the base 31.
[0025] The current collecting terminal in the present disclosure may have multiple 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 defined as being parallel to direction D1 and passing through a midpoint C of the current collecting terminal 30 in direction D2. Preferably, the first protrusion 32a is disposed in one region of the current collecting terminal 30 defined by the axis AX, and the second protrusion 32b is disposed 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. Alternatively, as shown in FIG. 7, the current collecting terminal 30 may have a single 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's say. L 11 L for 12The ratio (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 greater than L1. The ratio of L2 to L1 (L2 / L1) is, for example, 2 or more, optionally 5 or more, or 10 or more. L2 may be greater than L3. The ratio of L2 to L3 (L2 / L3) is, for example, 5 or more, optionally 10 or more, or 50 or more. L1 may be greater than L3. The ratio of L1 to L3 (L1 / L3) is, for example, 2 or more, optionally 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's say. 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 1.0 or less. Z The ratio of L3 to L Z ) is, for example, 0.8 or more, or may be 0.9 or more, or may be 0.95 or more. Z is, for example, 1.0 or less.
[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] As shown in Fig. 3, the main surface of the stack connection part W is joined to the inner surface S1 of the current collecting terminal 30. The "main surface of the stack connection part W" refers to a surface that constitutes the stack connection part W and whose normal direction coincides with the thickness direction of the connection part Y. The main surface of the stack connection part W may be joined to the inner surface S1 in direct contact with the inner surface S1, or may be joined via another member (for example, a conductive layer). The inner surface S1 of the current collecting terminal 30 and the stack 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 assembly and multiple current collecting tabs. In FIG. 2(b), the laminate film 40 covers the electrode assembly 10 and multiple current collecting tabs 20. As shown in FIGS. 2(b) and 2(c), the laminate film 40 covers a portion of each of the side surfaces S3 to S6 of the current collecting terminal 30. As shown in FIG. 2(c), a 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 (e.g., a resin layer for improving adhesion). Meanwhile, as shown in FIG. 1, a seal portion 41, where the laminate films 40 are fused together, is disposed along the opposing direction D1 of the electrode assembly 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 assembly in the present disclosure typically 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 electrode assembly typically has multiple power generation units stacked in the thickness direction. For example, the electrode assembly 10 shown in FIG. 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). 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. The positive electrode active material may be, for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of the conductive 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 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 the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and Li4Ti5O 12 Examples of oxide active materials include the above. 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 current from the positive electrode active material layer. Examples of materials for the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of shapes for the positive electrode current collector include 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, SUS, and nickel. Examples of shapes for the negative electrode current collector include foil.
[0036] The battery according to 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 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 disposed at a position where it does not overlap with the positive electrode active material layer 1. In addition, in FIG. 9, the negative electrode tab 5t extends from a side surface of the electrode body 10 in a direction intersecting with the stacking direction (direction D3) of the electrode body 10. Details of the negative electrode tab are similar to those of the positive electrode tab, and therefore will not be described here. As shown in FIG. 9, the positive electrode tab 4t may extend from one side surface of the electrode body 10, and the negative electrode tab 5t may extend from the other side surface of the electrode body 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 body (single-tab structure).
[0037] The current collecting terminal in the present disclosure is electrically connected to the current collecting tab of the electrode assembly. The current collecting terminal may have, for example, a plate shape. The current collecting terminal may be made of, for example, a metal such as aluminum or stainless steel.
[0038] The laminate film of the present disclosure has at least a structure in which a heat-sealing layer and a metal layer are laminated. The laminate film may also have a heat-sealing layer, a metal layer, and a resin layer in this order along the thickness direction. Examples of materials for the heat-sealing layer include olefin-based 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-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. It is particularly preferred that the battery be 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 mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.
[0040] 3. Battery manufacturing method The method for manufacturing a battery according to the present disclosure is not particularly limited as long as it can manufacture the above-described battery. FIG. 10 is a schematic perspective view illustrating a method for manufacturing a battery according to the present disclosure. First, as shown in FIG. 10(a), a negative electrode active material layer 2 is formed on each side of a negative electrode current collector 5. One method for forming the negative electrode active material layer is to apply a slurry containing materials for the negative electrode active material layer onto the negative electrode current collector and dry it. 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 disposed 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 laminated bodies α are stacked in the stacking direction D L 10(d), the tip of the positive electrode tab 4t is joined to form a laminate connection W, and the main surface of the laminate connection W is joined to the inner surface S1 of the current collecting terminal 30. Examples of methods for forming the laminate connection W include a method using welding such as laser welding or electron beam welding, a method using a conductive paste, and a method using solder. The method for joining the main surface of the laminate connection W to the inner surface S1 of the current collecting terminal 30 is the same as the method for forming the laminate connection 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 arrows. Thereafter, the negative electrode tab (not shown) is also subjected to the same treatment, and the obtained member is covered with a single laminate film to cover the electrode body so that a portion (at least the outer surfaces of each) of the two opposing current collecting terminals is exposed, thereby obtaining a battery.
[0042] B. Battery module 11 is a schematic perspective view illustrating a battery module according to 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 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 of the present disclosure preferably has three or more batteries. The three consecutively stacked batteries 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 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 case, by satisfying the following requirements, deformation of the collecting terminal can be effectively suppressed: (i) the joint portions of adjacent first protrusions 32a and the non-joint portions of adjacent first protrusions 32a are alternately arranged, (ii) the joint portions of adjacent second protrusions 32b and the non-joint portions of adjacent second protrusions 32b are alternately arranged, and (iii) the period of the joint portions and non-joint portions in the first protrusions 32a is shifted from the period of the joint portions and non-joint portions in the second protrusions 32b.
[0047] In addition, in FIG. 11, the stacking direction D of the electrode body L 12, 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. 12, LIn the battery pack, the plurality of first current collecting terminals 30A and the plurality of second current collecting terminals 30B may be arranged to overlap each other. In this case, the battery group joined by the plurality of first current collecting terminals 30A and the battery group joined by the plurality of 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 any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within 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 the side surfaces 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 plurality of 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 which connects the root portion and the connection portion, The plurality of current collecting tabs each have a stacked connection portion in which the connection portion is stacked in the 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 connection portion is joined to the inner surface, When viewed from above in the stacking direction of the electrode body, the current collecting terminal has a protruding portion that protrudes to an opposite side to the electrode body, The inner surface of the current collecting terminal is formed of a single flat surface.
2. An electrode body; a plurality of current collecting tabs extending from the side surfaces 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 plurality of 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 which connects the root portion and the connection portion, The plurality of current collecting tabs each have a stacked connection portion in which the connection portion is stacked in the 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 connection portion is joined to the inner surface, When viewed from above in the stacking direction of the electrode body, the current collecting terminal has a protruding portion that protrudes to an opposite side to the electrode body, a battery in which the entire main surface of the stacked connection portion is joined to the inner surface of the current collecting terminal.
3. A battery as described in claim 1 or claim 2, wherein a sealing portion where the laminate films are fused together is arranged along the opposing direction of the electrode body and the collector terminal.
4. The battery according to claim 1 or 2, 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 are curved to face each other.
5. An electrode body; a plurality of current collecting tabs extending from the side surfaces 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 plurality of 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 which connects the root portion and the connection portion, The plurality of current collecting tabs each have a stacked connection portion in which the connection portion is stacked in the 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 connection portion is joined to the inner surface, When viewed from above in the stacking direction of the electrode body, the current collecting terminal has a protruding portion that protrudes to an opposite side to the electrode body, The current collecting terminal has a first protruding portion and a second protruding portion as the protruding portion, In a plan view of the stacking direction of the electrode body, the opposing direction of the electrode body and the current collecting terminal is D １ and the D １ The direction perpendicular to ２ and the D １ and the D ２ When an axis passing through the midpoint of the current collecting terminal is defined as AX, the first protrusion is disposed in one region of the current collecting terminal partitioned by the AX, The battery, wherein the second protrusion is disposed in the other region of the current collecting terminal partitioned by the AX.
6. A battery module in which a plurality of batteries are stacked, A battery module, wherein the battery is the battery according to claim 1 or 2.
7. A battery module in which a plurality of batteries are stacked, The battery is the battery according to claim 5 , the battery module includes a battery A, a battery B, and a battery C as the batteries, the battery A, the battery B, and the battery C are stacked in succession, 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.
Citation Information
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