Battery and method for manufacturing the same

Abstract

The present invention relates to a battery in which reliability is appropriately improved, and a manufacturing method of the battery. The manufacturing method of the battery disclosed herein includes: a fitting step (S1) in which at least a part of an exterior body (12) is brought into abutment with a sealing plate (14), and the exterior body and / or the sealing plate is deformed, thereby fitting the exterior body and the sealing plate; and a joining step (S2) in which the exterior body (12) and the sealing plate (14) are joined.

Description

Technical Field

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

[0002] Lithium-ion rechargeable batteries and similar batteries typically include an electrode body with electrodes and a battery casing that houses the electrode body. The battery casing typically includes an outer body with an opening that houses the electrode body and a sealing plate that seals the opening of the outer body. For example, this type of battery casing is disclosed in Patent Document 1 below.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-093119 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, the battery casing described above is formed, for example, by embedding a sealing plate into the outer casing and joining the periphery of the sealing plate. However, with this embedding alone, there is a tendency for the position of the sealing plate relative to the outer casing to be difficult to fix, and thus the sealing plate sometimes shifts. In such cases, stable joining may be difficult. Furthermore, if a gap is created between the outer casing and the sealing plate due to its shift, tiny metal particles (so-called sputtering) that may be generated during joining can enter the outer casing through this gap, potentially degrading battery performance, and is therefore not preferred.

[0008] This disclosure was made in view of the above circumstances, and its main objective is to provide a battery with appropriately improved reliability and a method for manufacturing the battery.

[0009] Solution for solving the problem

[0010] To achieve this objective, this disclosure provides a method for manufacturing a battery, the battery comprising: one or more electrode bodies, each electrode body including a positive electrode and a negative electrode; and a battery casing housing the electrode bodies, having an outer casing and a sealing plate for sealing an opening of the outer casing. The method for manufacturing the battery includes the following steps: an fitting step, in which at least a portion of the outer casing abuts against the sealing plate, deforming the outer casing and / or the sealing plate to fit the outer casing with the sealing plate; and a joining step, joining the outer casing with the sealing plate.

[0011] In the battery manufacturing method described above, during the fitting process, at least a portion of the outer casing abuts against the sealing plate, deforming either the outer casing or the sealing plate to fit the outer casing and the sealing plate together. This allows for proper fixation of the sealing plate relative to the outer casing, thus enabling stable bonding. Furthermore, this fixation prevents sputtering or other contaminants that may occur during bonding from entering the outer casing, thereby appropriately preventing degradation of battery performance caused by sputtering. Therefore, according to the battery manufacturing method described above, a battery with appropriately improved reliability can be obtained.

[0012] In one technical solution of the battery manufacturing method disclosed herein, the outer casing has a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. The area of ​​the first side walls is larger than that of the second side walls, and the sealing plate is rectangular in shape.

[0013] In a preferred embodiment of the battery manufacturing method, in the fitting process, at least a portion of the sealing plate is disposed within the opening of the outer casing for fitting, and in the joining process, the outer casing is joined to the sealing plate while pressing the pair of first sidewalls toward the interior of the outer casing. Regarding batteries with an outer casing having a first sidewall area larger than the second sidewall area (e.g., an outer casing with a rectangular opening), as an example of a method for obtaining a battery with improved reliability, a method can be described that prevents gaps from forming at the joint between the outer casing and the sealing plate on the long side of the opening. Therefore, in the joining process, pressing the pair of first sidewalls toward the interior of the outer casing while joining the outer casing to the sealing plate is effective from the viewpoint of obtaining a battery with more adequately improved reliability.

[0014] In a preferred embodiment of the battery manufacturing method disclosed herein, during the aforementioned fitting process, the outer casing is fitted to the sealing plate at least on its short side. For example, as described above, when the pair of first sidewalls are pressed towards the interior of the outer casing, the outer casing may deform, creating a gap on the short side of the opening of the outer casing. In this case, sputtering or other contaminants that may occur during joining could enter the outer casing through this gap. On the other hand, as described above, when the outer casing is fitted to the sealing plate at least on its short side, such a gap is less likely to occur on the short side of the outer casing, thus appropriately preventing sputtering from entering the outer casing. Therefore, a battery with improved reliability can be obtained.

[0015] In one technical solution of the battery manufacturing method disclosed herein, at least a portion of the aforementioned abutting outer body and either of the aforementioned sealing plate have an R-surface or a C-surface, and the other abutting body has a corner portion for deforming the aforementioned R-surface or C-surface.

[0016] In one technical solution of the battery manufacturing method, the R-surface or C-surface is present in the portion of the sealing plate opposite to the bottom wall.

[0017] In one embodiment of the battery manufacturing method, a stepped portion with the corner portion is present near the opening of the outer casing.

[0018] In a preferred embodiment of the battery manufacturing method, during the fitting process, at least a portion of the outer casing abuts against the sealing plate such that the acute angle formed by the direction of the bottom wall's extension and the tangent of the portion contacting the R-surface or C-surface and the corner is within the range of 10° to 45°. Details will be described later. According to this battery manufacturing method, a battery with improved reliability can be obtained.

[0019] In a preferred embodiment of the battery manufacturing method, an interlocking portion is formed in the aforementioned interlocking process. This interlocking portion includes a recess with a depth ranging from 0.01 mm to 0.3 mm in the wall thickness direction of the sealing plate, and this recess is formed from the aforementioned corner portion. Details will be described later. According to the battery manufacturing method with this structure, a battery with more appropriately improved reliability can be obtained.

[0020] Additionally, according to other aspects, a battery manufactured by any of the battery manufacturing methods disclosed herein is provided. The battery comprises: one or more electrode bodies, each electrode body including a positive electrode and a negative electrode; and a battery casing housing the electrode bodies, having an outer casing and a sealing plate sealing an opening of the outer casing, wherein at least a portion of the outer casing and at least a portion of the sealing plate are engaged with the other, the outer casing engaging with the sealing plate.

[0021] In one of the battery technical solutions disclosed herein, a thickened portion is present near the engagement portion of at least a portion of the outer casing or at least a portion of the sealing plate into which one of the components is engaged.

[0022] In one of the battery technical solutions disclosed herein, a recess is present in the aforementioned fitting portion, and the acute angle formed by the direction of extension of the aforementioned bottom wall and the tangent of the aforementioned recess is within the range of 10° to 45°.

[0023] In one of the battery technical solutions disclosed herein, the fitting portion has a recess with a depth in the wall thickness direction of the sealing plate ranging from 0.01 mm to 0.3 mm. Attached Figure Description

[0024] Figure 1 This is a perspective view schematically illustrating one embodiment of a battery.

[0025] Figure 2 It is along Figure 1 A schematic longitudinal section of line II-II.

[0026] Figure 3 It is along Figure 1 A schematic longitudinal section of line III-III.

[0027] Figure 4 It is along Figure 1 A schematic cross-sectional view of the IV-IV line.

[0028] Figure 5 This is a schematic perspective view of the electrode assembly mounted on the sealing plate.

[0029] Figure 6 It is a schematic three-dimensional view of an electrode body with a positive second collector and a negative second collector installed.

[0030] Figure 7 This is a schematic diagram showing the structure of the wound electrode.

[0031] Figure 8 This is a flowchart illustrating a method for manufacturing a battery according to one embodiment.

[0032] Figure 9 This is a perspective view schematically showing the outer casing used in a battery manufacturing method according to one embodiment.

[0033] Figure 10 It is a perspective view schematically showing a sealing plate with a positive terminal, a negative terminal, a first positive collector, a first negative collector, an internal insulating component for the positive terminal, and an internal insulating component for the negative terminal.

[0034] Figure 11 It is Figure 10 A 3D view of the sealing plate after it has been flipped over.

[0035] Figure 12A This is a schematic cross-sectional view illustrating the contact between a portion of the outer casing and a sealing plate in the fitting process of a battery manufacturing method according to one embodiment. It schematically shows... Figure 12C A longitudinal section view of the shape before fitting.

[0036] Figure 12BThis is a schematic cross-sectional view illustrating the fitting of a portion of the outer casing to a sealing plate in the fitting process of a battery manufacturing method according to one embodiment. It schematically represents... Figure 12C A longitudinal section view of the shape before joining.

[0037] Figure 12C It is along Figure 1 A schematic longitudinal section of line XII-XII.

[0038] Figure 13 This is a schematic diagram used to illustrate the joining process of one embodiment.

[0039] Figure 14A This is the second embodiment. Figure 12A Corresponding diagram.

[0040] Figure 14B This is the second embodiment. Figure 12B Corresponding diagram.

[0041] Figure 15A This is the third embodiment. Figure 12A Corresponding diagram.

[0042] Figure 15B This is the third embodiment. Figure 12B Corresponding diagram.

[0043] Explanation of reference numerals in the attached figures

[0044] 10. Battery casing; 12, 112, 212. Outer casing; 14, 114, 214. Sealing plate; 15. Liquid filling hole; 16. Sealing component; 17. Gas vent valve; 18, 19. Terminal insertion hole; 20. Electrode assembly; 20a-20c. Electrode body; 22. Positive electrode; 24. Negative electrode; 26. Spacer; 30. Positive terminal; 32. Positive external conductive component; 40. Negative terminal; 42. Negative external conductive component; 50. Positive current collector; 60. Negative current collector; 70. Positive internal insulating component; 80. Negative internal insulating component; 90. Gasket; 92. External insulating component; 100. Battery; 200. Pressing component. Detailed Implementation

[0045] Hereinafter, several preferred embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. It should be noted that, apart from matters specifically mentioned in this specification, matters necessary for the implementation of this disclosure (e.g., the general structure and manufacturing process of a battery not characterized by this disclosure) can be understood as design matters based on those skilled in the art. This disclosure can be implemented based on the content disclosed in this specification and common technical knowledge in the art. The following description is not intended to limit the technology disclosed herein to the following embodiments. Furthermore, in this specification, the expression "A to B" indicating a numerical range means A or more and B or less. Therefore, it includes cases exceeding A and below B.

[0046] It should be noted that, in this manual, "battery" refers to all energy storage devices capable of extracting electrical energy, encompassing both primary and secondary batteries. Furthermore, in this manual, "secondary battery" refers to all energy storage devices capable of repeated charging and discharging, including lithium-ion secondary batteries, nickel-metal hydride batteries, and other so-called storage batteries (chemical batteries), as well as capacitors such as double-layer capacitors (physical batteries).

[0047] First, the structure of the battery 100 obtained by the battery manufacturing method of this embodiment will be described. Figure 1 It is a 3D image of battery 100. Figure 2 It is along Figure 1 A schematic longitudinal section of line II-II. Figure 3 It is along Figure 1 A schematic longitudinal section of line III-III. Figure 4 It is along Figure 1 A schematic cross-sectional view of line IV-IV. In the following description, the reference numerals L, R, F, Rr, U, and D in the figures represent left, right, front, back, top, and bottom, respectively, and the reference numerals X, Y, and Z in the figures represent the direction of the short side of battery 100, the direction of the long side orthogonal to the short side, and the up and down direction, respectively. These directions are merely for illustrative purposes and do not limit the arrangement of battery 100 in any way.

[0048] like Figure 2As shown, the battery 100 includes a battery casing 10 and an electrode body 20. In addition to the battery casing 10 and the electrode body 20, the battery 100 of this embodiment also includes a positive terminal 30, a positive external conductive member 32, a negative terminal 40, a negative external conductive member 42, an external insulating member 92, a positive current collector 50, a negative current collector 60, a positive internal insulating member 70, and a negative internal insulating member 80. Furthermore, although not shown in the figures, the secondary battery 100 of this embodiment also includes an electrolyte. Here, the battery 100 is a lithium-ion secondary battery. The internal resistance of the battery 100 can be, for example, approximately 0.2 mΩ to 2.0 mΩ.

[0049] Furthermore, the battery casing 10 includes an outer body 12, a sealing plate 14, and a gas vent valve 17. The outer body 12 is a flat, square container with an opening 12h on one side. Specifically, as... Figure 1 As shown, the outer casing 12 has a generally rectangular bottom wall 12a, a pair of first side walls 12b extending upward U from the short side of the bottom wall 12a and facing each other, and a pair of second side walls 12c extending upward U from the long side of the bottom wall 12a and facing each other. The area of ​​the first side wall 12b is larger than the area of ​​the second side wall 12c. An opening 12h is formed on the upper surface of the outer casing 12 surrounded by the pair of first side walls 12b and the pair of second side walls 12c. The opening 12h has a short side 12d and a long side 12e. A sealing plate 14 is installed on the outer casing 12 to block the opening 12h of the outer casing 12. The sealing plate 14 is a generally rectangular sheet material when viewed from above. The sealing plate 14 has a short side 14d and a long side 14e. The sealing plate 14 faces the bottom wall 12a of the outer casing 12. The battery casing 10 is formed by joining (e.g., welding) a sealing plate 14 around the opening 12h of the outer casing 12. The joining of the sealing plate 14 can be performed, for example, by welding such as laser welding. It should be noted that the structure of the outer casing 12 and the sealing plate 14 of the battery 100 of this embodiment will be described later.

[0050] Details will be described later. In this embodiment, the outer body 12 (specifically, the outer body 12' before fitting) is engaged with at least a portion of the sealing plate 14 (specifically, the sealing plate 14' before fitting) by abutting against at least a portion of the sealing plate 14. While not particularly limited to this, in such cases, it is preferable, for example, that the material constituting the outer body 12 is harder than the material constituting the sealing plate 14. Examples of materials constituting the outer body 12 include materials formed by plastically processing and work-hardening aluminum or aluminum alloys (e.g., A1050-H18, A3003-H18, etc.) and aluminum or aluminum alloys (e.g., A1050-O, A3003-O). Examples of materials constituting the sealing plate 14 include aluminum and aluminum alloys (e.g., A1050-O, A3003-O). It should be noted that, from the viewpoint of improving processability, trace elements (such as Fe) can be appropriately added to the constituent materials. Furthermore, the Brinell hardness (HB) of the materials constituting the outer casing 12 and the sealing plate 14 is not particularly limited as long as it achieves the technical effects disclosed herein, and can be set to approximately 10 or more. From the viewpoint of appropriately ensuring the mechanical strength of the battery casing 10, it is preferably 20 or more, more preferably 30 or more, and even more preferably 40 or more. Additionally, from the viewpoint of facilitating the fitting process described later, the Brinell hardness (HB) of the materials constituting the outer casing 12 and the sealing plate 14 is approximately 100 or less, preferably 90 or less. Furthermore, the difference in the Brinell hardness of the materials constituting the outer casing 12 and the sealing plate 14 can be set to approximately 20 to 50 (for example, approximately 25 to 45). However, the Brinell hardness value is not limited to these values. It should be noted that the Brinell hardness can, for example, be based on values ​​from JIS Z 2243.

[0051] Furthermore, there are no particular limitations regarding the thickness (hereinafter also simply referred to as "thickness") of the outer casing 12 and the sealing plate 14 in the wall thickness direction, as long as the technical effects disclosed herein are achieved. From the viewpoint of increasing the internal volume of the battery 100 and seeking to reduce the weight of the battery, it is preferable that the thickness of the outer casing 12 is small. In addition, it is preferable that the side that is forced to deform during the fitting process described later, namely the sealing plate 14, has excellent mechanical strength (in other words, a thicker thickness). Therefore, it is preferable that the thickness of the outer casing 12 is less than the thickness of the sealing plate 14. These thicknesses can be appropriately designed according to the type of materials constituting the outer casing and the sealing plate, the method of use, etc. This design can be implemented through experiments conducted by those skilled in the art.

[0052] like Figure 1 and Figure 2As shown, a gas vent valve 17 is formed on the sealing plate 14. The gas vent valve 17 is configured to open when the pressure inside the battery housing 10 reaches a predetermined value, thereby venting gas from the battery housing 10. In addition to the gas vent valve 17, the sealing plate 14 also has an injection hole 15 and two terminal insertion holes 18 and 19. The injection hole 15 communicates with the internal space of the outer casing 12 and is an opening provided for injecting electrolyte during the manufacturing process of the battery 100. The injection hole 15 is sealed by a sealing member 16. A blind rivet is preferably used as the sealing member 16, for example. This allows the sealing member 16 to be securely fixed inside the battery housing 10.

[0053] Figure 5 This is a perspective view schematically showing the electrode assembly 20 installed on the sealing plate 14' (hereinafter also simply referred to as "sealing plate 14'") before fitting. In this embodiment, a plurality of (here, three) electrode bodies 20a, 20b, and 20c are housed inside the battery casing 10. It should be noted that the number of electrode bodies housed inside a single battery casing 10 is not particularly limited; it can be one or more (multiple). Figure 2 As shown, on one side of the long side direction Y of each electrode body 20 ( Figure 2 A positive current collector 50 is arranged on the left side, and on the other side in the long side direction Y ( Figure 2 A negative current collector 60 is arranged on the right side. Furthermore, electrode bodies 20a, 20b, and 20c are each connected in parallel. However, electrode bodies 20a, 20b, and 20c can also be connected in series. The electrode body 20 here is covered by an electrode body holder 29 made of resin sheet (see reference). Figure 3 The battery casing 10 is housed inside the outer casing 12.

[0054] Figure 6 This is a schematic three-dimensional view of the electrode body 20a. Figure 7 This is a schematic diagram showing the structure of electrode 20a. It should be noted that the following detailed explanation uses electrode 20a as an example, but electrode 20b and 20c can also be designed with the same structure.

[0055] like Figure 7 As shown, the electrode body 20a has a positive electrode 22, a negative electrode 24, and a spacer 26. Here, the electrode body 20a is a wound electrode body formed by stacking strip-shaped positive electrodes 22 and strip-shaped negative electrodes 24 with two strip-shaped spacers 26 between them and winding them around a winding axis WL. However, the structure of the electrode body is not limited to the technology disclosed herein. For example, the electrode body may also be a stacked electrode body formed by stacking multiple square (typically rectangular) positive electrodes and multiple square (typically rectangular) negative electrodes in an insulated state.

[0056] The electrode body 20a has a flat shape. The electrode body 20a is disposed inside the outer casing 12 with its winding axis WL approximately parallel to the long side direction Y. Specifically, as... Figure 3 As shown, the electrode body 20a has a pair of curved portions (R portions) 20r opposite to the bottom wall 12a and the sealing plate 14 of the outer body 12, and a flat portion 20f connecting the pair of curved portions 20r and opposite to the second side wall 12c of the outer body 12. The flat portion 20f extends along the second side wall 12c.

[0057] like Figure 7 As shown, the positive electrode 22 has a positive current collector 22c and a positive active material layer 22a and a positive protective layer 22p fixed to at least one surface of the positive current collector 22c. However, the positive protective layer 22p is not necessary and can be omitted in other embodiments. The positive current collector 22c is strip-shaped. The positive current collector 22c is made of conductive metals such as aluminum, aluminum alloy, nickel, and stainless steel. The positive current collector 22c is a metal foil, specifically an aluminum foil.

[0058] At one end of the long side Y of the positive current collector 22c ( Figure 7 Multiple positive electrode tabs 22t are provided at the left end of the strip. These positive electrode tabs 22t are spaced apart (intermittently) along the long side of the strip-shaped positive electrode 22. The multiple positive electrode tabs 22t face one side of the axial direction of the winding axis WL. Figure 7 The positive electrode tab 22t protrudes to a position further outward than the spacer 26 (on the left side). It should be noted that the positive electrode tab 22t can be located on the opposite side of the axial direction of the winding axis WL ( Figure 7 (As shown on the right side), they can also be respectively provided on both sides of the axial direction of the winding axis WL. The positive electrode tab 22t is part of the positive electrode current collector 22c and is made of metal foil (aluminum foil). However, the positive electrode tab 22t can also be a separate component from the positive electrode current collector 22c. At least a portion of the positive electrode tab 22t does not form the positive electrode active material layer 22a and the positive electrode protective layer 22p, thus exposing the positive electrode current collector 22c.

[0059] like Figure 4 As shown, multiple positive electrode tabs 22t are located at one end of the axial direction of the winding axis WL. Figure 4 The left end of each electrode is stacked to form a positive electrode tab group 23. Furthermore, the multiple positive electrode tabs 22t are bent with their outer ends aligned. This improves the retractability into the battery casing 10, thereby miniaturizing the battery 100. Figure 2 As shown, the positive electrode tab group 23 is electrically connected to the positive terminal 30 via the positive electrode current collector 50. Specifically, the positive electrode tab group 23 and the second positive electrode current collector 52 are connected at the connection part J (see reference). Figure 4Furthermore, the second positive collector 52 is electrically connected to the positive terminal 30 via the first positive collector 51. It should be noted that the dimensions of the multiple positive electrode tabs 22t (length along the long side direction Y and width orthogonal to the long side direction Y, refer to...) can be appropriately adjusted based on their connection to the positive collector 50, for example, according to their formation position. Figure 7 Here, the dimensions of the multiple positive electrode tabs 22t are different so that the outer ends are aligned when bent.

[0060] like Figure 7 As shown, the positive electrode active material layer 22a is arranged in a strip shape along the long side direction of the strip-shaped positive electrode current collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (e.g., a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide) capable of reversibly absorbing and releasing charge carriers. When the total solids content of the positive electrode active material layer 22a is set to 100% by mass, the positive electrode active material can also account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The positive electrode active material layer 22a can also contain any components other than the positive electrode active material, such as conductive materials, binders, various additives, etc. For example, carbon materials such as acetylene black (AB) can be used as conductive materials. For example, polyvinylidene fluoride (PVdF) can be used as a binder.

[0061] like Figure 7 As shown, the positive electrode protective layer 22p is disposed in the longitudinal direction Y at the boundary between the positive electrode current collector 22c and the positive electrode active material layer 22a. The positive electrode protective layer 22p is located at one end of the positive electrode current collector 22c along the axial direction of the winding axis WL. Figure 7 (The left end). However, the positive electrode protective layer 22p can also be provided at both ends in the axial direction. The positive electrode protective layer 22p is provided in a strip shape along the positive electrode active material layer 22a. The positive electrode protective layer 22p contains inorganic filler (e.g., alumina). When the total solids content of the positive electrode protective layer 22p is set to 100% by mass, the inorganic filler can also account for approximately 50% by mass or more, typically 70% by mass or more, for example, 80% by mass or more. The positive electrode protective layer 22p can also contain any components other than inorganic filler, such as conductive materials, binders, various additives, etc. The conductive materials and binders can also be the same as those exemplified as conductive materials and binders that can be included in the positive electrode active material layer 22a.

[0062] like Figure 7As shown, the negative electrode 24 has a negative electrode current collector 24c and a negative electrode active material layer 24a fixed to at least one surface of the negative electrode current collector 24c. The negative electrode current collector 24c is strip-shaped. The negative electrode current collector 24c is made of conductive metals such as copper, copper alloy, nickel, and stainless steel. The negative electrode current collector 24c is a metal foil, specifically a copper foil.

[0063] At one end of the winding axis WL of the negative current collector 24c ( Figure 7 Multiple negative electrode tabs 24t are provided at the right end of the strip. These multiple negative electrode tabs 24t are spaced apart (intermittently) along the long side of the strip-shaped negative electrode 24. The multiple negative electrode tabs 24t are respectively oriented towards one side of the axial direction. Figure 7 The right side of the negative electrode 24t protrudes to a position further outward than the spacer 26. However, the negative electrode tab 24t can be located at the other end in the axial direction. Figure 7 The negative electrode tab 24t can be located at either end of the negative electrode current collector 24c, or at either end of the negative electrode current collector 24c. The negative electrode tab 24t is part of the negative electrode current collector 24c and is made of metal foil (copper foil). However, the negative electrode tab 24t can also be a separate component from the negative electrode current collector 24c. At least a portion of the negative electrode tab 24t has an area where the negative electrode active material layer 24a is not formed, exposing the negative electrode current collector 24c.

[0064] like Figure 4 As shown, one end of the multiple negative electrode tabs 24t in the axial direction ( Figure 4 The negative electrode tabs 24t are stacked at their right ends to form a negative electrode tab group 25. The negative electrode tab group 25 is preferably positioned symmetrically to the positive electrode tab group 23 in the axial direction. Furthermore, the plurality of negative electrode tabs 24t are bent with their outer ends aligned. This improves the retractability into the battery casing 10, thereby miniaturizing the battery 100. Figure 2 As shown, the negative electrode tab assembly 25 is electrically connected to the negative terminal 40 via the negative electrode current collector 60. Specifically, the negative electrode tab assembly 25 and the second negative electrode current collector 62 are connected at the connection part J (see reference). Figure 4 Furthermore, the second negative collector 62 is electrically connected to the negative terminal 40 via the first negative collector 61. Similar to the plurality of positive electrode tabs 22t, the plurality of negative electrode tabs 24t are each of different sizes so that the outer ends are aligned when bent.

[0065] like Figure 7As shown, the negative electrode active material layer 24a is arranged in a strip shape along the long side of the strip-shaped negative electrode current collector 24c. The negative electrode active material layer 24a contains a negative electrode active material (e.g., carbon materials such as graphite) capable of reversibly absorbing and releasing charge carriers. When the total solids content of the negative electrode active material layer 24a is set to 100% by mass, the negative electrode active material can also account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The negative electrode active material layer 24a can also contain any components other than the negative electrode active material, such as binders, dispersants, various additives, etc. For example, rubbers such as styrene-butadiene rubber (SBR) can be used as binders. For example, cellulose-based materials such as carboxymethyl cellulose (CMC) can be used as dispersants.

[0066] like Figure 7 As shown, spacer 26 is a component used to insulate the positive electrode active material layer 22a of the positive electrode 22 from the negative electrode active material layer 24a of the negative electrode 24. As spacer 26, a porous sheet made of resin such as polyethylene (PE) or polypropylene (PP) is preferably preferred. Spacer 26 may also have a substrate portion made of a porous sheet of resin and a heat resistance layer (HRL) provided on at least one surface of the substrate portion and containing an inorganic filler. As an inorganic filler, alumina, boehmite, aluminum hydroxide, titanium dioxide, etc., can be used, for example.

[0067] The electrolyte can be the same as before, without any particular limitations. For example, the electrolyte may be a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt. Non-aqueous solvents may include carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Supporting salts may include fluorinated lithium salts such as LiPF6. However, the electrolyte may also be in solid form (solid electrolyte) and integrated with the electrode body 20.

[0068] like Figure 2 As shown, the positive terminal 30 is inserted into one end of the sealing plate 14 in the Y direction along its long side. Figure 2 The positive terminal 30 is preferably made of metal, more preferably of, for example, aluminum or an aluminum alloy. The negative terminal 40 is inserted into the other end of the sealing plate 14 in the Y direction along its long side. Figure 2The terminal insertion hole 19 is formed at the right end of the battery casing 10. It should be noted that the negative terminal 40 is preferably made of metal, more preferably of, for example, copper or a copper alloy. Here, these electrode terminals (positive terminal 30, negative terminal 40) protrude from the same side of the battery casing 10 (specifically, the sealing plate 14). However, the positive terminal 30 and the negative terminal 40 may also protrude from different sides of the battery casing 10. Furthermore, the electrode terminals (positive terminal 30, negative terminal 40) inserted into the terminal insertion holes 18, 19 are preferably fixed to the sealing plate 14 by riveting or the like.

[0069] As mentioned above, such as Figure 2 As shown, the positive terminal 30 is located inside the outer casing 12 and connects to the positive terminals 22 of each electrode body 20 (see reference 22) via the positive current collector 50 (positive first current collector 51, positive second current collector 52). Figure 7 Electrical connection. The positive terminal 30 is insulated from the sealing plate 14 by the positive internal insulating member 70 and the gasket 90. It should be noted that the positive internal insulating member 70 has a base 70a and a protrusion 70b located between the first current collector 51 of the positive electrode and the sealing plate 14. Furthermore, the positive terminal 30, which protrudes to the outside of the battery housing 10 through the terminal insertion hole 18, is connected to the positive external conductive member 32 outside the sealing plate 14. On the other hand, as Figure 2 As shown, the negative terminal 40 is connected inside the outer casing 12 via the negative current collector 60 (the first negative current collector 61 and the second negative current collector 62) to the negative terminals 24 of each electrode body 20 (see reference). Figure 7 Electrical connection. The negative terminal 40 is insulated from the sealing plate 14 by the negative internal insulating member 80 and the gasket 90. It should be noted that, similar to the positive internal insulating member 70, the negative internal insulating member 80 also has a base 80a and a protrusion 80b located between the first negative current collector 61 and the sealing plate 14. Furthermore, the negative terminal 40, which protrudes to the outside of the battery casing 10 through the terminal insertion hole 19, is connected to the negative external conductive member 42 outside the sealing plate 14. Furthermore, the external insulating member 92 is located between the aforementioned external conductive members (positive external conductive member 32, negative external conductive member 42) and the sealing plate 14. The external insulating member 92 can be used to insulate the external conductive members 32 and 42 from the sealing plate 14.

[0070] Next, the method for manufacturing the battery according to this embodiment will be described. However, it is not intended to limit the battery manufacturing method disclosed herein to the method described below. The battery manufacturing method disclosed herein may further include other steps as needed. In addition, the order of the steps may be appropriately changed as long as the technical effects disclosed herein can be achieved.

[0071] Figure 8This is a flowchart used to explain the manufacturing method of the battery according to this embodiment. For example... Figure 8 As shown, the battery manufacturing method of this embodiment includes an inserting process (step S1) and a bonding process (step S2). Each process will be described below.

[0072] First, prepare the sealing plate 14' on which the electrode body (here, electrode body assembly 20) is installed (refer to...). Figure 5 ) and outer casing 12' (refer to) Figure 9 Here, Figure 5 The complex (hereinafter, also referred to as "complex 2") was produced by... Figure 10 After the first compound (hereinafter also referred to as "the first compound") is installed, Figure 6 The electrode body, as shown, is manufactured with a positive second collector and a negative second collector installed.

[0073] In the fabrication of the first composite, firstly, the positive terminal 30, the first positive current collector 51, the positive internal insulating member 70, the negative terminal 40, the first negative current collector 61, and the negative internal insulating member 80 (see reference) are installed on the sealing plate 14'. Figure 10 and Figure 11 Furthermore, the positive terminal 30, the first positive current collector 51, and the internal positive insulating member 70 are fixed to the sealing plate 14', for example, by riveting. The riveting is performed by clamping a gasket 90 between the outer surface of the sealing plate 14' and the positive terminal 30, and then clamping the internal positive insulating member 70 between the inner surface of the sealing plate 14' and the first positive current collector 51. It should be noted that the material of the gasket 90 can also be the same as that of the internal positive insulating member 70. Specifically, before riveting, the positive terminal 30 is inserted sequentially from above the sealing plate 14' into the through hole of the gasket 90, the terminal insertion hole 18 of the sealing plate 14', the through hole of the internal positive insulating member 70, and the through hole 51h of the first positive current collector 51, and protrudes downwards from the sealing plate 14'. Then, the portion of the positive terminal 30 that protrudes further downward than the sealing plate 14' is riveted by applying a compressive force in the vertical direction Z. Thus, at the front end of the positive terminal 30 ( Figure 2 A riveting portion is formed at the lower end of the plate. Through this riveting process, the gasket 90, the positive electrode internal insulation member 70, and the positive electrode first collector 51 are integrally fixed to the sealing plate 14', and the terminal insertion hole 18 is sealed. It should be noted that the riveting portion can also be welded to the positive electrode first collector 51. This can further improve the conductivity reliability.

[0074] The fixing of the negative terminal 40, the first negative current collector 61, and the internal insulating member 80 can be performed in the same manner as the positive terminal side described above. That is, before riveting, the negative terminal 40 is inserted sequentially from above the sealing plate 14' into the through hole of the gasket, the terminal insertion hole 19 of the sealing plate 14', the through hole of the internal insulating member 80, and the through hole 61h of the first negative current collector 61, causing it to protrude downwards from the sealing plate 14'. Then, the portion of the negative terminal 40 that protrudes downwards from the sealing plate 14' is riveted by applying a compressive force in the vertical direction Z. Thus, at the front end of the negative terminal 40 ( Figure 2 A riveting part is formed at the lower end of the component. In this way, the first composite can be obtained.

[0075] Next, the second composite material is fabricated. That is, the electrode assembly 20 is fabricated and integrated with the sealing plate 14'. Specifically, firstly, as... Figure 6 As shown, three electrode bodies 20a, each equipped with a positive second collector 52 and a negative second collector 62, are prepared and arranged as electrode bodies 20a, 20b, and 20c in the short-side direction X. At this time, electrode bodies 20a, 20b, and 20c can all be positioned with their positive second collector 52 on one side in the long-side direction Y. Figure 5 The left side), the second negative collector 62 is disposed on the other side in the long side direction Y ( Figure 5 They are arranged in parallel on the right side.

[0076] Next, as Figure 4 As shown, with the multiple positive electrode tabs 22t bent, the first positive electrode current collector 51 fixed to the sealing plate 14' and the second positive electrode current collector 52 of the electrode bodies 20a, 20b, and 20c are respectively joined. Similarly, with the multiple negative electrode tabs 24t bent, the first negative electrode current collector 61 fixed to the sealing plate 14' and the second negative electrode current collector 62 of the electrode bodies 20a, 20b, and 20c are respectively joined. As a joining method, welding methods such as ultrasonic welding, resistance welding, and laser welding can be used. Welding based on high-energy rays such as lasers is particularly preferred. Through this welding process, joints are formed in the recesses of the second positive electrode current collector 52 and the second negative electrode current collector 62. In this way, a second composite material can be obtained.

[0077] Here, the structure of the outer body 12' (hereinafter also referred to as "outer body 12'") and the sealing plate 14' before fitting will be described. Figure 9 Showing the outer casing 12', Figure 10 The sealing plate 14' is shown. (See attached image.) Figure 9As shown, the outer body 12' has a stepped portion 12s' with a corner portion 12t' near the opening 12h of the second sidewall 12c' (hereinafter also simply referred to as "second sidewall 12c'") before fitting. Additionally, as... Figure 10 As shown, the sealing plate 14' has a pair of R-side walls 14r' with curved surfaces (R-surfaces) and a pair of other side walls 14f' in the portion opposite to the bottom wall 12a. The R-side walls 14r' are present on the short side 14d side of the sealing plate 14'. The outer body 12' and sealing plate 14' described above can be manufactured, for example, by molding (the same applies to the following outer bodies 112', 212', and sealing plates 114', 214'). It should be noted that in this embodiment, the angle θ' formed by the corner 12t' is set to about 90°, but it is not limited to this. The angle formed by the corner can be set to about 75° to 105°, for example. There is no particular limitation on the angle formed by the corner as long as it can achieve the technical effect disclosed herein. In addition, the thickness in the wall thickness direction of the stepped portion 12s' (i.e., Figure 12A The width in the Y direction can be appropriately designed according to the type of material constituting the outer casing, the method of use, etc. This design can be implemented through experiments conducted by those skilled in the art.

[0078] (Matching process: S1)

[0079] In the fitting process (step S1) of this embodiment, at least a portion of the outer body 12' abuts against the sealing plate 14', and the sealing plate 14' is deformed, thereby fitting the outer body 12' and the sealing plate 14' together. In addition, in this fitting process, at least a portion of the sealing plate 14' is placed within the opening 12h of the outer body 12' for fitting.

[0080] Figure 12A This is a schematic cross-sectional view illustrating the contact between the outer casing 12' and the sealing plate 14'. More specifically, it shows the contact along... Figure 1 A schematic longitudinal section view of the morphology of the section before fitting along line XII-XII. (See attached image.) Figure 12A As shown, in the fitting step S1 of the battery manufacturing method of this embodiment, at least a portion of the outer casing 12' abuts against the sealing plate 14'. Here, Figure 12A In this context, θ1 represents the direction of extension toward the bottom wall 12a (i.e., Figure 1The acute angle θ1 is the angle formed by the line S drawn from the Y direction and the tangent T of the portion in contact with the corner 12t' of the R sidewall 14r' and the step portion 12s'. The value of the acute angle θ1 is not particularly limited as long as it achieves the technical effect disclosed herein. From the viewpoint of appropriately suppressing stress concentration at the contact portion during fitting, the acute angle θ1 is preferably 5° or more, more preferably 10° or more, and even more preferably 20° or more. From the viewpoint of appropriately suppressing sputtering caused by friction between the contact portions during fitting, the upper limit of the acute angle θ is preferably 50° or less, more preferably 45° or less, and even more preferably 40° or less. The acute angle θ1 can, for example, be set within the range of 10° to 45°.

[0081] Figure 12B This is a schematic cross-sectional view illustrating the fitting of the outer casing 12' and the sealing plate 14'. More specifically, it shows the fit along... Figure 1 A schematic longitudinal cross-sectional view of the cross-section of line XII-XII before and after fitting. In the fitting process of this embodiment, the outer body 12' and the sealing plate 14' are fitted together by deforming the sealing plate 14'. Figure 12A As shown, this deformation is performed, for example, by pressing the sealing plate 14' into the outer casing 12' in the direction of the hollow arrow. This pressing can be performed, for example, by a pressing device. The pressing load during pressing is not particularly limited as long as it achieves the technical effects disclosed herein. The pressing load also depends on the materials constituting the outer casing and the sealing plate; for example, when using the outer casing 12' and sealing plate 14' with the structure described above, it can be set to approximately 50N to 300N (e.g., approximately 100N to 200N). It should be noted that when using materials other than those listed above as the materials constituting the outer casing 12' and sealing plate 14', those skilled in the art can appropriately determine the pressing load by conducting preliminary tests.

[0082] In addition, such as Figure 12B As shown, after the fitting process in this embodiment, the fitting portion P is formed. Here, the fitting portion P includes a recess O formed by the corner portion 12t' of the stepped portion 12s'. The depth Q of the recess O in the wall thickness direction of the sealing plate 14 (in other words, Figure 12BThe depth of engagement (in the Z direction) is not particularly limited as long as the technical effects disclosed herein are achieved. From the viewpoint of properly fixing the sealing plate 14 to the outer casing 12, the depth Q is preferably 0.01 mm or more, more preferably 0.05 mm or more, and even more preferably 0.1 mm or more. From the viewpoint of ensuring appropriate stress applied to the sealing plate 14 and appropriately suppressing the deterioration of the joint V described later, the depth Q is preferably 0.5 mm or less, more preferably 0.4 mm or less, and even more preferably 0.3 mm or less. For example, the depth Q can be set in the range of 0.01 mm to 0.3 mm. It should be noted that the thickness of the sealing plate 14 in this embodiment is approximately 2.8 mm.

[0083] (Jointing process: S2)

[0084] In the joining process (step S2) of this embodiment, the outer casing 12 is joined to the sealing plate 14. More specifically, the sealing plate 14 is joined to the edge of the opening 12h of the outer casing 12 to seal the opening 12h. The welding joint between the outer casing 12 and the sealing plate 14 can be performed, for example, by laser welding.

[0085] In addition, in this embodiment, the following is used: Figure 13 The pressing component 200 shown is engaged. It should be noted that, in Figure 13 For ease of explanation, only the outer casing 12 is described here. For example, regarding a battery with an outer casing having a first sidewall area larger than the second sidewall area (e.g., an outer casing with a rectangular opening), as an example of a method to obtain a battery with improved reliability, a method can be cited where a gap is prevented from forming at the joint between the outer casing and the sealing plate on the long side of the opening. Therefore, in this embodiment, by pressing the pair of first sidewalls 12b toward the interior of the outer casing 12 (refer to arrow a), the formation of the gap at the joint is suppressed, and the outer casing 12 is joined to the sealing plate 14. However, when pressed toward arrow a, sometimes the outer casing 12 deforms in the direction of arrow b, creating a gap W on the short side 12d of the outer casing (refer to arrow a). Figure 13 The outer casing 12”). In such a case, sputtering or other contaminants that may occur during joining could potentially enter the outer casing 12” through the gap W. On the other hand, in this embodiment, since the outer casing 12 is fitted to the sealing plate 14 at least on the short side 14d side, it is difficult for a gap W to be generated on the short side 12d side of the outer casing, thus effectively preventing sputtering from entering the outer casing.

[0086] Figure 12C This is a schematic cross-sectional view showing the shape after the outer body 12 and the sealing plate 14 are joined. Figure 12C It can also be said to be along Figure 1A schematic longitudinal section view of line XII-XII. Here, the depth of joint V (in other words, the depth of joint V) is shown. Figure 12C The depth in the Z direction is not particularly limited as long as the technical effects disclosed herein are achieved. The depth of the aforementioned joint V is preferably formed, for example, between the surface of the sealing plate 14 and the fitting portion P. For example, when the distance from the surface of the sealing plate 14 to the fitting portion P is set to 100%, the depth of the aforementioned joint V can be formed in the range of approximately 30% to 70% (e.g., 40% to 60%) of the distance from the surface of the sealing plate.

[0087] After the above-described bonding process, electrolyte is injected through the injection hole 15, and the injection hole 15 is blocked with the sealing member 16, thereby sealing the battery 100. As described above, the battery 100 can be manufactured. In addition, the battery 100 obtained by the battery manufacturing method of this embodiment has, for example, the following characteristics.

[0088] As described above, the battery 100 obtained by the battery manufacturing method of this embodiment has a fitting portion P formed by at least a portion of the sealing plate 14 engaging with at least a portion of the outer casing 12 (see reference). Figure 12C Additionally, a recess O exists at the fitting portion P. Here, Figure 12C In this context, θ1' represents the direction of extension toward the bottom wall 12a (i.e., Figure 1 The acute angle formed by the line S' drawn from the Y direction and the tangent T' of the recess O. For example, when the outer body 12' and the sealing plate 14' are brought together with an acute angle θ1 in the range of 10° to 45°, the acute angle θ1' in the fitting part P formed after the fitting process can be in the range of 10° to 45°.

[0089] Additionally, for example, when the outer body 12' and the sealing plate 14' are fitted together with a depth Q in the range of 0.01 mm to 0.3 mm, a recess O in the wall thickness direction of the sealing plate 14 can be formed in the fitting portion P.

[0090] Furthermore, in this embodiment, when the sealing plate 14' is pressed into the outer body 12' in the direction of the hollow arrow, it is pressed in such a way that it is easier to press in the portion closer to the center than the two ends of the short side 12d of the outer body 12' (typically, when the length of the short side 12d is set to 100%, this means an area about 10% to 20% from the center of the short side). Therefore, in this embodiment, a deeper engagement can be observed in the fitting portion P formed on the short side 12d than in the portion closer to the center than the two ends.

[0091] The above description illustrates several embodiments of this disclosure, but these embodiments are merely examples. Furthermore, this disclosure can be implemented in various other ways. This disclosure can be implemented based on the content disclosed in this specification and common technical knowledge in the field. The technology described in the claims includes various modifications and alterations to the embodiments illustrated above. For example, a portion of the above embodiments can be replaced with other modifications, or other modifications can be added to the above embodiments. Additionally, if a technical feature is not described as essential, it can be appropriately deleted.

[0092] For example, in the above embodiment, the case of a square battery casing with a rectangular opening has been described, but it is not limited to this. The technology disclosed herein may also include, for example, a square battery casing with a square opening, a cylindrical battery casing, or various other battery casings.

[0093] For example, in the above embodiment, the case where the sealing plate and the outer body are fitted only on the short side has been described, but this is not a limitation. The technology disclosed herein may also fit only one of the short sides (a pair of short sides) of the sealing plate and the outer body. Furthermore, the technology disclosed herein may fit only on the long side of the sealing plate and the outer body, or it may fit on both the short and long sides of the sealing plate and the outer body.

[0094] For example, in the above embodiment, an R-surface (R-sidewall) is formed integrally on one or both short sides of the sealing plate, but this is not a limitation. As long as the technical effects disclosed herein are utilized, the R-surface (R-sidewall) can also be formed on a portion of the short sides of the sealing plate, for example. When the length of the short side of the sealing plate (the length of one short side) is set to 100%, the R-surface (R-sidewall) can be formed on one short side in the range of approximately 20% or more, preferably 30% or more, 40% or more, 50% or more, 60% or more, or 70% or more. The same can be done for the other short side. Furthermore, when the entire circumference of the sealing plate is set to 100%, it is preferable to form the R-surface (R-sidewall) in an area of ​​approximately 5% to 20%. It should be noted that the proportion of the R-sidewall formed on one short side (or, one long side) and the other short side (or, the other long side) can be the same or different. The same applies to the formation of the C-surface and corners of the sealing plate. In addition, in the above embodiment, it is set that a deeper engagement is found on the short side of the outer body, especially in the central part, but it is not limited to this, and the engagement can also be uniform on the short side.

[0095] Figure 14A This is the second embodiment. Figure 12A Corresponding diagram, Figure 14B This is the second embodiment. Figure 12BCorresponding diagram. (See image below) Figure 14A As shown, in the fitting process of the second embodiment, at least a portion of the second sidewall 112c' (hereinafter also simply referred to as "second sidewall 112c'") of the outer body 112' (hereinafter also simply referred to as "outer body 112'") before fitting is brought into contact with the sealing plate 114' (hereinafter also simply referred to as "sealing plate 114'") before fitting. Here, the second sidewall 112c' has a sidewall 112u' with a C-surface and an angle. In addition, the sealing plate 114' has a corner portion 114t'. Here, Figure 14A In this context, θ2 represents the direction extending toward the bottom wall 12a (i.e., Figure 1 The acute angle θ2 is the angle formed by the line S” drawn from the Y direction and the tangent T” of the portion that contacts the sidewall 112u' and the corner 114t'. The value of the acute angle θ2 is not particularly limited as long as the technical effect disclosed herein is achieved; for example, it can be set within the range described in the explanation of the acute angle θ1.

[0096] In addition, such as Figure 14A As shown, in the second embodiment, the outer body 112' (specifically, the second sidewall 112c') is deformed to fit into the sealing plate 114'. This deformation is performed, for example, by pressing the sealing plate 114' toward the direction of the hollow arrow relative to the outer body 112'. This pressing can be performed, for example, by a pressing device or the like. The pressing load during pressing can be determined, for example, with reference to the above description. Furthermore, as... Figure 14B As shown, the fitting portion P' formed after the fitting process has a recess O', the depth Q' of which in the wall thickness direction of the sealing plate 114 (in other words, Figure 14B The engagement depth in the Z direction can be the same as that of Q described above. Then, by performing the same joining as in the above embodiment, a battery in which the outer body 112 (specifically, the second sidewall 112c) and the sealing plate 114 are fitted together can be obtained.

[0097] Figure 15A This is the third embodiment. Figure 12A Corresponding diagram, Figure 15B This is the third embodiment. Figure 12B Corresponding diagram. (See image below) Figure 15A As shown, in the fitting process of the third embodiment, at least a portion of the second sidewall 212c' (hereinafter also simply referred to as "second sidewall 212c'") of the outer body 212' (hereinafter also simply referred to as "outer body 212'") before fitting is brought into contact with the sealing plate 214' (hereinafter also simply referred to as "sealing plate 214'") before fitting. Here, the second sidewall 212c' has a corner portion 212t', and the outer body 212' has a corner portion 214t'.

[0098] In addition, such as Figure 15AAs shown, in the third embodiment, the outer body 212' is fitted into the sealing plate 214' by deforming the corner 212t' of the sealing plate 214'. This deformation is performed, for example, by pressing the sealing plate 214' into the direction of the hollow arrow relative to the outer body 212'. This pressing can be performed, for example, by a pressing device or the like. The pressing load during pressing can be determined, for example, with reference to the above description. Furthermore, as... Figure 15B As shown, the fitting portion P formed after the fitting process has a recess O, and the depth Q of the recess in the wall thickness direction of the sealing plate 214 is (in other words, Figure 15B The engagement depth in the Z direction can be the same as Q as described above. It should be noted that in the third embodiment, there is a thickened portion R near the fitting portion P” of the engaging party (here, the sealing plate 214). Then, by performing the same joining as in the above embodiment, a battery in which the outer body 212 (specifically, the second sidewall 212c) and the sealing plate 214 are fitted together can be obtained.

Claims

1. A method for manufacturing a battery, wherein, This battery has the following features: One or more electrode bodies, each electrode body comprising a positive electrode and a negative electrode; and The battery casing, which houses the electrode body, has an outer body and a sealing plate that seals the opening of the outer body, wherein... The method for manufacturing the battery includes the following steps: The fitting process involves bringing at least a portion of the outer casing into contact with the sealing plate, deforming the outer casing and / or the sealing plate, thereby fitting the outer casing into the sealing plate; and In the joining process, the outer casing is joined to the sealing plate. Near the opening of the outer casing, there is a stepped portion with corners. During the fitting process, the corners are engaged with the sealing plate by pressing the sealing plate toward the outer casing in the thickness direction, thereby deforming the sealing plate and fitting the outer casing with the sealing plate. The sealing plate has an R-surface or a C-surface, and the corner of the outer body deforms the R-surface or C-surface. The angle formed by the direction of the bottom wall of the outer body extending and the tangent of the part of the R-surface or C-surface that contacts the corner is an acute angle.

2. The method for manufacturing a battery according to claim 1, wherein, The outer casing has a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall. The area of ​​the first side walls is larger than that of the second side walls, and the sealing plate is rectangular.

3. The method for manufacturing a battery according to claim 2, wherein, In the fitting process, at least a portion of the sealing plate is disposed within the opening of the outer casing to perform the fitting, and... In the joining process, the outer body is joined to the sealing plate while the pair of first sidewalls are pressed toward the inside of the outer body.

4. The method for manufacturing a battery according to claim 2, wherein, In the fitting process, the outer body is fitted to the sealing plate on at least the short side of the rectangular sealing plate.

5. The method for manufacturing a battery according to claim 3, wherein, In the fitting process, the outer body is fitted to the sealing plate on at least the short side of the rectangular sealing plate.

6. The method for manufacturing a battery according to claim 1, wherein, The R-surface or C-surface exists on the portion of the sealing plate opposite to the bottom wall.

7. The method for manufacturing a battery according to claim 1, wherein, In the fitting process, at least a portion of the outer casing abuts against the sealing plate in such a manner that the acute angle formed by the direction of the bottom wall extension and the tangent of the portion of the R-surface or C-surface that contacts the corner is within the range of 10° to 45°.

8. The method for manufacturing a battery according to claim 1, wherein, In the fitting process, a fitting portion is formed, which includes a recess in the wall thickness direction of the sealing plate with a depth in the range of 0.01 mm to 0.3 mm, and the recess is formed by the corner portion.

9. A battery, wherein, This battery has the following features: One or more electrode bodies, each electrode body comprising a positive electrode and a negative electrode; and The battery casing houses the electrode body and includes an outer casing and a sealing plate that seals the opening of the outer casing. The battery has at least one portion of the outer casing and at least one portion of the sealing plate engaged with the other in a fitting portion. The outer casing is joined to the sealing plate. Near the opening of the outer casing, there is a stepped portion with corners. In the fitting portion, by pressing the sealing plate toward the outer casing in the thickness direction of the sealing plate, the corners are engaged with the sealing plate, thereby deforming the sealing plate. The sealing plate has an R-side or a C-side, and the corner of the outer body deforms the R-side or C-side. The fitting portion includes a recess formed by the corner, and the angle between the direction of the bottom wall of the outer body extending and the tangent of the recess is an acute angle.

10. The battery according to claim 9, wherein, A thickened portion exists near the engagement portion of at least a portion of the outer casing or at least a portion of the sealing plate of the one into which the casing is engaged.

11. The battery according to claim 9 or 10, wherein, The acute angle between the direction of the bottom wall extension and the tangent of the recess is within the range of 10° to 45°.

12. The battery according to claim 9 or 10, wherein, The depth of the recess in the wall thickness direction of the sealing plate is in the range of 0.01mm to 0.3mm.

Images