Battery and method for manufacturing a battery

Abstract

The present application provides a battery capable of improving the assembly of an outer body and a cover body, and a manufacturing method of the battery. The battery of the present application includes: an outer body having a rectangular flat bottom wall and a pair of main walls integrally erected on the long side of the bottom wall, and a protruding portion protruding toward each other on the end of the pair of main walls opposite to the bottom wall; an electrode body accommodated in the outer body; and a cover body formed in a "convex" shape having a narrow portion and a wide portion when viewed in the direction extending from the long side of the bottom wall, and arranged in a manner that the narrow portion is clamped by the protruding portion, the protruding portion of the outer body and the cover body are welded to each other, and the ratio of the Young's modulus of the electrode body to the rigidity rate of the outer body (the Young's modulus of the electrode body: the rigidity rate of the outer body) is 1:1-1:2 in the direction from the protruding portion side to the bottom wall side.

Description

Technical Field

[0001] This invention relates to a battery and a method for manufacturing the battery. Background Technology

[0002] Patent document 1 discloses a sealed battery in which the cover is sealed to the opening of the upper part of the battery can by welding. At least one of the long side and the short side of the opening end of the battery can has a portion that extends beyond the upper part of the cover when the cover is fitted into the opening end. The portion that extends beyond the upper part of the cover is bent inward and then welded to seal it.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2001-167740 Summary of the Invention

[0004] From the perspective of improving battery productivity, there is a need for batteries that can be assembled efficiently.

[0005] The purpose of this invention is to provide a battery and a method for manufacturing the same, which can improve the assemblability of the outer casing and the cover.

[0006] The inventors have discovered that the above-mentioned problem can be achieved through the following method:

[0007] Method 1

[0008] A battery that has the following features:

[0009] The outer body has a rectangular flat bottom wall and a pair of main body walls integrally erected on the long side of the bottom wall, and protrusions on the ends of the pair of main body walls on the opposite side of the bottom wall that protrude toward each other.

[0010] Electrode bodies, housed within the outer casing; and

[0011] The cover is formed into a "convex" shape having a narrow portion and a wide portion when viewed from the direction extending from the long side of the bottom wall, and is arranged such that the narrow portion is held between the protrusion.

[0012] The protrusion of the outer body is welded to the cover.

[0013] Regarding the direction from the protrusion side toward the bottom wall side, the ratio of the Young's modulus of the electrode body to the rigidity of the outer body (Young's modulus of the electrode body: rigidity of the outer body) is 1:1 to 1:2.

[0014] Method 2

[0015] According to the battery of method 1, the electrode body has a heat-conducting plate on the bottom wall side and / or the cover side.

[0016] The Young's modulus of the electrode body is the Young's modulus including the electrode body and the heat-conducting sheet.

[0017] Method 3

[0018] According to the battery of method 1, the electrode body has a terminal portion capable of closing the opening of the outer body on the short side of the bottom wall.

[0019] Method 4

[0020] A method for manufacturing a battery, which is a method for manufacturing a battery according to any one of methods 1 to 3, comprising:

[0021] The opening process involves moving the protrusions of the outer body in a direction that separates them from each other, thereby opening the ends.

[0022] In the electrode insertion process, the electrode is inserted into the outer casing whose ends are open.

[0023] In the cover insertion process, the cover is inserted into the end of the outer casing into which the electrode body is inserted;

[0024] The clamping process involves moving the protrusions toward each other so that the narrow portion in the cover is clamped by the protrusions.

[0025] The pressurization process involves applying pressure to the outer casing and the electrode body in a direction perpendicular to the bottom wall; and

[0026] In the sealing process, the narrow portion of the cover is welded to the end of the outer body to seal the end of the outer body.

[0027] Method 5

[0028] According to the manufacturing method of method 4, the pressurization process and the sealing process are performed simultaneously.

[0029] Invention Effects

[0030] According to the present invention, a battery and a method for manufacturing the same are provided that can improve the assemblability of the outer casing and the cover. Attached Figure Description

[0031] Figure 1 This is a schematic perspective view of the battery involved in this embodiment.

[0032] Figure 2 This is a schematic perspective view showing the electrode body of the battery according to this embodiment.

[0033] Figure 3This is a schematic perspective view showing the outer casing of the battery according to this embodiment.

[0034] Figure 4 This is a schematic perspective view showing the cover of the battery according to this embodiment.

[0035] Figure 5 This is a schematic cross-sectional view showing the internal structure of the battery involved in this embodiment.

[0036] Figure 6 This is a schematic cross-sectional view showing the internal structure of the battery involved in this embodiment.

[0037] Figure 7 This is a schematic cross-sectional view illustrating the battery manufacturing method according to this embodiment. Detailed Implementation

[0038] The embodiments of the present invention will now be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the spirit of the invention.

[0039] 1. Battery

[0040] The battery of the present invention comprises: an outer body having a rectangular flat bottom wall and a pair of main body walls integrally erected on the long side of the bottom wall, and protrusions protruding from the ends of the pair of main body walls on the side opposite to the bottom wall in a direction approaching each other; an electrode body housed in the outer body; and a cover body formed into a "convex" shape having a narrow portion and a wide portion when viewed from the direction extending from the long side of the bottom wall, provided such that the narrow portion is held by the protrusions, the protrusions of the outer body and the cover body are welded to each other, and the ratio of the Young's modulus of the electrode body to the stiffness of the outer body (Young's modulus of the electrode body: stiffness of the outer body) is 1:1 to 1:2 in the direction from the protrusion side toward the bottom wall side.

[0041] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, for ease of explanation, in each figure, arrow UP is appropriately shown as the upward direction of the battery, arrow FR as the forward direction of the battery, and arrow LH as the left direction of the battery. Therefore, in the following description, unless specifically stated otherwise, up / down, front / back, and left / right directions refer to the up / down, front / back, and left / right directions within the battery, but are not limited to these directions.

[0042] like Figure 1 As shown, the battery 10 involved in this embodiment is an all-solid-state battery, which includes: Figure 2 Electrode body 12 shown; Figure 3 The outer casing 20 shown houses the electrode body 12; and Figure 4The cover 30 shown closes the upper end of the outer casing 20 (the end opposite to the bottom wall 22 described later) that houses the electrode body 12. Furthermore, both the outer casing 20 and the cover 30 are made of a metal such as aluminum alloy.

[0043] 1-1. Electrode body

[0044] like Figure 2 As shown, the electrode body 12 is formed as a rectangular plate with its thickness along the rear-to-rear direction. Metal terminal portions 14 are pre-attached to the left and right sides of the electrode body 12 via welding or the like. The terminal portions 14 are larger than the left and right sides of the electrode body 12 and are large enough to close the opening 18 of the outer casing 20 (described later). Furthermore, on the outer surface of the terminal portions 14, a pair of electrode terminals 16, each with a predetermined protrusion height that appears approximately square when viewed from the left-right direction, are integrally formed at predetermined intervals in the vertical direction.

[0045] 1-2. Exterior body

[0046] like Figure 3 As shown, the outer casing 20 has a rectangular flat bottom wall 22 with its long side facing left and right, and a pair of main body walls 24 integrally formed on the long side of the bottom wall 22. Furthermore, the short side of the bottom wall 22 in the outer casing 20 has an opening 18. And, at the upper ends of the pair of main body walls 24 (the ends opposite to the bottom wall 22), protrusions 26 protruding towards each other are integrally formed.

[0047] Here, the protrusion length L of the protrusions 26 in the direction of approaching each other (reference) Figure 5 The same applies. That is, the narrow portion 32 of the cover 30 at the upper end of the sealing outer body 20, as described later, is a structure disposed at the center of its upper end in the front-rear direction. Furthermore, as... Figure 5 As shown, a thermally conductive sheet 28 of a specified thickness, formed of a silicone resin material, is attached to the inner surface (upper surface) of the bottom wall 22 of the outer casing 20, covering approximately the entire surface.

[0048] 1-3. Cover

[0049] like Figure 4 As shown, the cover 30 is formed into a "convex" shape with narrow upper and lower portions 32 and a wide portion 34 when viewed in a direction extending from the long side of the bottom wall 22 of the outer casing 20. Figure 5 As shown, the width of the lower wide portion 34 constituting the cover 30 in the front-back direction is the same as the spacing between the pair of main body walls 24, and the upper narrow portion 32 constituting the cover 30 is formed at the center of the width direction (front-back direction) of the wide portion 34.

[0050] That is, half the difference between the width of the wide portion 34 and the width of the narrow portion 32 is the same as the protruding length L of the protrusion 26, and the cover 30 is configured such that when it is disposed at the upper end of the outer body 20 (between the upper ends of a pair of main body walls 24), its narrow portion 32 is clamped by the protrusion 26 in the front-rear direction (see reference). Figure 5 ).

[0051] In other words, the opposing end faces 26A of each protrusion 26 (see reference) Figure 3 ) respectively abut against the front and rear facing sides 32A of the narrow portion 32 (reference) Figure 4 The protrusion 26 fits into the stepped portion 36 formed by the narrow portion 32 and the wide portion 34. In this state, the cover 30 is joined to the upper end of the outer body 20 by welding, thus sealing the upper end of the cover.

[0052] Furthermore, the upper surface (outer surface) of the narrow portion 32 and the upper surface (outer surface) of the protrusion 26 form a surface-to-surface structure (see reference). Figure 5 That is, the thickness (height) H1 of the narrow portion 32 is the same as the plate thickness of the protrusion 26 (outer body 20). Furthermore, the thickness (height) H2 of the wide portion 34 is formed to be thicker than the thickness H1 of the narrow portion 32 (let's say H2 > H1). And, as... Figure 5 As shown, a thermally conductive sheet 38 of a predetermined thickness, formed of a silicone resin material, is attached to the lower surface of the width portion 34 (the inner surface of the cover 30), covering approximately the entire surface.

[0053] In the above-described structure, the battery of the present invention, as follows: Figure 6 As shown, the outer body protrusion is welded to the cover, and the ratio of the Young's modulus of the electrode body to the rigidity of the outer body (Young's modulus of the electrode body: rigidity of the outer body) is 1:1 to 1:2 in the direction from the protrusion side to the bottom wall side. Here, the direction from the protrusion side to the bottom wall side can also be described as a direction perpendicular to the bottom wall of the outer body.

[0054] The battery of the present invention begins by sealing the electrode body within an outer casing, with the protrusion of the outer casing welded to the cover. Depending on the physical properties of the material of the electrode body or the manufacturing method, during this welding process, the electrode body is less prone to deformation than the outer casing, and thus the outer casing may deform due to bending or other reasons. This deformation can lead to insufficient contact between the protrusion of the outer casing and the cover, resulting in difficulties in these welds at times.

[0055] In the battery of the present invention, the ratio of Young's modulus of the electrode body to the rigidity of the outer casing (Young's modulus of the electrode body: rigidity of the outer casing) is 1:1 to 1:2 in the direction from the protrusion side to the bottom wall side. Therefore, the outer casing is less prone to deformation than the battery. Thus, after the battery is housed in the outer casing, the outer casing is less prone to bending or other deformation. As a result, the contact between the protrusion of the outer casing and the cover body becomes good, and these welding processes become easier.

[0056] Furthermore, in this invention, from the viewpoint of ensuring battery heat dissipation, the electrode body can have heat-conducting sheets on the bottom wall side and / or the cover side. Moreover, since resin-based heat-conducting sheets are relatively soft, they can mitigate the hardness of the electrode body, thereby reducing Young's modulus when the electrode body and the heat-conducting sheet are considered as a single unit. In this case, the Young's modulus of the electrode body is defined as the Young's modulus including both the electrode body and the heat-conducting sheet.

[0057] like Figure 6 As shown, Young's modulus can be determined from the stress of the longitudinal strain generated when a force k0 is applied to press the electrode body 10 against the bottom wall 22 side. Furthermore, the stiffness ratio can be determined from the stress generated when a force k1 is applied to bend the protrusion 26 of the outer casing 20 from the protrusion side toward the bottom wall side. Here, when calculating the stiffness ratio, the stress can be calculated based on the following formula:

[0058] Stress σ = Deflection δ1 caused by load + Deflection δ2 caused by the self-weight of the protrusion

[0059] Here,

[0060] Deflection caused by load δ1=(F×L) 3 ) / (3×E×I)

[0061] Deflection caused by its own weight δ2=(w×L) 4 ) / (8×E×I)

[0062] F is the load, L is the length of the protrusion, and E is Young's modulus.

[0063] Furthermore, I (second moment of section) = b × h 3 / 12, w=ρ×g×A.

[0064] Additionally, b is the width of the protrusion, h is the height of the protrusion, A is the cross-sectional area of ​​the section perpendicular to the long side of the protrusion, ρ is the density of the protrusion, and g is the acceleration due to gravity.

[0065] Here, stress σ = (F × L) / Z, Z (section modulus) = b × h 2 / 6, therefore, together with the above formula, we can calculate the stiffness (Young's modulus).

[0066] 2. Battery manufacturing method

[0067] First, such as Figure 7 As shown in (A), a heat-conducting sheet 28 is attached to the inner surface of the bottom wall 22 of the outer casing 20. Then, as... Figure 7 As shown in (B), the protrusions 26 of the outer casing 20 are moved in a direction separating from each other, causing the upper end of the outer casing 20 to open (opening process), and the electrode body 12 is inserted from above into the outer casing 20 whose upper end has opened (electrode body insertion process). Figure 7 (C) shows the state in which the electrode body 12 is inserted (accommodated) in the outer body 20.

[0068] Next, as Figure 7 As shown in (D), the cover 30 is inserted into the upper end of the outer casing 20, which houses the electrode body 12 (cover insertion process). Additionally, a heat-conducting sheet 38 is pre-attached to the lower surface of the wide portion 34 of the cover 30. Furthermore, although not shown in the diagram, this is similar to... Figure 7 As shown in (B), the protrusions 26 of the outer body 20 are moved in a direction that separates them from each other, thereby opening the upper end of the outer body 20 and inserting it into the cover 30.

[0069] Thus, if the cover 30 is inserted into the upper end of the outer casing 20 (the side above the electrode body 12), then as... Figure 7 As shown in (E), the protrusions 26 are moved closer to each other, thereby clamping the narrow portion 32 in the cover 30 and sealing the upper end of the outer casing 20 (sealing process). That is, at the end face 26A of each protrusion 26 (refer to...) Figure 3 ) abuts against each side 32A of the narrow portion 32 (see reference) Figure 4 In the state of being sealed, the cover 30 is joined to the upper end of the outer body 20 by welding.

[0070] In the manufacturing method of the present invention, a pressurizing step is performed before or simultaneously with the sealing step, in which the outer body 20 and the electrode body 10 are pressurized in a direction perpendicular to the bottom wall 22. The pressure is applied until the cover 30 contacts the upper end of the outer body 20. During the welding (sealing step) after the electrode body 10 is inserted, if the electrode body 10 is hard, the outer body 20 will bend and fail to maintain its shape, thus opening. Therefore, by suppressing the deformation of the outer body 20 through the pressurizing step, and matching the ratio of the Young's modulus of the electrode body to the rigidity of the outer body to be 1:1 to 1:2, the sealing step can be performed more easily.

[0071] The battery 10 of this embodiment has been described above with reference to the accompanying drawings. However, the battery 10 of this embodiment is not limited to the one shown in the drawings, and appropriate design changes can be made without departing from the spirit of the present invention.

[0072] Example

[0073] 3. Examples 1-11 and Comparative Examples 1-14

[0074] 3-1. Fabrication of Electrode Body and External Components

[0075] Formed as Figures 2-4 The electrode bodies A1-A5, outer casings B1-B5, and cover are shown. The Young's modulus and stiffness of the electrode bodies are shown in Table 1 below.

[0076] 3-2. Battery Assembly

[0077] pass Figure 6 The method shown describes assembling the battery by combining electrode bodies A1-A5 and outer casings B1-B5 as shown in Table 2. The welding of the outer casing to the cover is performed by applying pressure in a direction perpendicular to the bottom wall of the outer casing, with the outer casing in contact with the electrode bodies and the cover with the upper end of the outer casing.

[0078] 3-3. Results

[0079] The results are shown in Table 1 and Table 2.

[0080] [Table 1]

[0081]

[0082] [Table 2]

[0083]

[0084] As shown in Table 1, successful welding was achieved in combinations where the ratio of Young's modulus of the electrode body to the rigidity of the outer casing (Young's modulus of the electrode body: rigidity of the outer casing) was 1:1 to 1:2 (each embodiment). In other combinations (each comparative example), welding was not sufficiently performed, and leaks were observed.

[0085] Symbol Explanation

[0086] 10-Battery, 12-Electrode body, 20-Outer body, 22-Bottom wall, 24-Main body wall, 26-Protrusion, 30-Cover body, 32-Narrow part, 34-Wide part.

Claims

1. A battery, characterized in that, have: The outer body has a rectangular flat bottom wall and a pair of main body walls integrally erected on the long side of the bottom wall, and protrusions on the ends of the pair of main body walls on the opposite side of the bottom wall that protrude toward each other. Electrode body, which is housed within the outer casing; and The cover is formed into a "convex" shape having a narrow portion and a wide portion when viewed from the direction extending from the long side of the bottom wall, and is arranged such that the narrow portion is held between the protrusion. The protrusion of the outer body is welded to the cover. Regarding the direction from the protrusion side toward the bottom wall side, the ratio of the Young's modulus of the electrode body to the rigidity of the outer body (Young's modulus of the electrode body: rigidity of the outer body) is 1:1 to 1:

2.

2. The battery according to claim 1, characterized in that, The electrode body has heat-conducting plates on the bottom wall side and / or the cover side. The Young's modulus of the electrode body is the Young's modulus including the electrode body and the heat-conducting sheet.

3. The battery according to claim 1, characterized in that, The electrode body has a terminal portion capable of closing the opening of the outer body on the short side of the bottom wall.

4. A method for manufacturing a battery, comprising the method for manufacturing a battery according to any one of claims 1 to 3, characterized in that, include: The opening process involves moving the protrusions of the outer body in a direction that separates them from each other, thereby opening the ends. The electrode insertion process involves inserting the electrode into the outer casing whose ends are open. The cover insertion process involves inserting the cover into the end of the outer casing into which the electrode body is inserted. The clamping process involves moving the protrusions toward each other so that the narrow portion in the cover is clamped by the protrusions. The pressurization process applies pressure to the outer casing and the electrode body in a direction perpendicular to the bottom wall; and The sealing process involves welding the narrow portion of the cover to the end of the outer body to seal the end of the outer body.

5. The manufacturing method according to claim 4, characterized in that, The pressurization process and the sealing process are performed simultaneously.

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