Method of manufacturing a battery, battery and battery intermediate

Abstract

Provided is a battery manufacturing method, a battery, and a battery intermediate, which can suppress hot melt defects. The battery manufacturing method includes: a placement step in which a resin layer is placed along at least one surface of a current collecting terminal in a thickness direction of the current collecting terminal; a housing step in which a power generating element is housed in an outer case; and a sealing step in which the power generating element is sealed inside the outer case. The current collecting terminal has a terminal flat portion and a terminal inclined portion, and the resin layer has a resin layer flat portion and a resin layer inclined portion. In the placement step, the resin layer is placed on the current collecting terminal in such a manner that θ1 and θ2 satisfy θ1 > θ2. In the placement step, θ1 is an angle formed by a straight line obtained by extending the terminal flat portion and the terminal inclined portion, and θ2 is an angle formed by a straight line obtained by extending the resin layer flat portion and the resin layer inclined portion.

Description

Technical Field

[0001] This application relates to a method for manufacturing a battery, a battery, and battery intermediates. Background Technology

[0002] Laminated batteries are known to utilize laminated films to seal power generation elements. These laminated batteries have a structure where current collector terminals connected to the power generation element extend to the outside, and the current collector terminals are held in place by the laminated film and thermally bonded.

[0003] In recent years, research has focused on increasing the thickness of current collector terminals to meet the demands for higher battery performance. However, increasing the thickness of the current collector terminals can lead to gaps between the terminals, particularly at their width, and the laminated film. These gaps compromise the airtightness of the laminated battery, allowing moisture to seep in and degrade the power generation components. Furthermore, in the case of liquid-type batteries, this can result in electrolyte leakage through these gaps. Therefore, it is necessary to prevent such poor heat sealing.

[0004] To address this problem, Japanese Patent Application Publication No. 2006-164784 discloses a laminated battery having current collector terminals whose thickness gradually decreases towards the outer side in the width direction. According to this type of laminated battery, it is difficult to generate gaps between the end of the current collector terminal and the laminated film.

[0005] According to the laminated battery described in Japanese Patent Application Publication No. 2006-164784, it is indeed difficult to create a gap between the end of the current collector terminal and the laminated film. However, due to manufacturing tolerances, a gap may occur between the end of the current collector terminal and the laminated film during heat sealing. Therefore, there is room for improvement in the technology disclosed in Japanese Patent Application Publication No. 2006-164784. Summary of the Invention

[0006] This application provides a method for manufacturing a battery and a battery capable of suppressing poor heat bonding.

[0007] The first aspect of the battery disclosed herein is a method for manufacturing a battery comprising: a power generation element; an outer casing housing the power generation element; and a current collector terminal electrically connected to the power generation element and configured to extend outward from the outer casing. The method further comprises: a placement step in which a resin layer is disposed along at least one surface of the current collector terminal connected to the power generation element in the thickness direction; a housing step in which the power generation element is housed within the outer casing; and a sealing step in which the power generation element is sealed inside the outer casing by heat fusion, wherein the resin layer is heat-fused to the outer casing, and the current collector terminal... The collector terminal has a flat portion with a constant thickness and a sloping portion connected to the flat portion and thinning towards the outside of the width direction of the collector terminal. The sloping portion is provided at at least one end of the collector terminal in the width direction. The resin layer has a flat portion disposed along the surface of the flat portion and a sloping portion connected to the flat portion and disposed along the surface of the sloping portion. In the configuration process, the resin layer is configured on the collector terminal such that θ1 and θ2 satisfy θ1 > θ2. In the configuration process, θ1 is an angle formed by the flat portion and the straight line obtained by extending the sloping portion, and θ2 is an angle formed by the flat portion and the straight line obtained by extending the sloping portion.

[0008] In the battery manufacturing method of the first aspect of this disclosure, the power generation element may be sealed inside the outer casing in a sealing process such that θ3 and θ4 satisfy θ3 > θ4. In the sealing process, θ3 may be an angle formed by a straight line obtained by extending the flat portion of the terminal and the inclined portion of the terminal, and θ4 may be an angle formed by a straight line obtained by extending the flat portion of the resin layer and the inclined portion of the resin layer.

[0009] In the battery manufacturing method of the first aspect of this disclosure, the resin layer and the outer casing may be thermally bonded together using a heating rod in the sealing process. Alternatively, the outer casing may have a portion corresponding to the flat portion of the resin layer (i.e., a flat portion of the outer casing) and a portion corresponding to the inclined portion of the resin layer (i.e., an inclined portion of the outer casing). Alternatively, the heating rod may have a portion corresponding to the flat portion of the outer casing (i.e., a flat portion of the heating rod) and a portion corresponding to the inclined portion of the outer casing (i.e., an inclined portion of the heating rod). Alternatively, the relationship θ1≥θy>θ2 may be satisfied, where θy can be an angle formed by the inner surface of the flat portion of the heating rod and a straight line obtained by extending the inner surface of the inclined portion of the heating rod.

[0010] In the battery manufacturing method of the first aspect of this disclosure, the resin layer may have a first region fused to the outer casing and a second region not fused to the outer casing in the length direction. Alternatively, the first region of the resin layer may have a first region flat portion disposed along the surface of the terminal flat portion and a first region inclined portion disposed along the surface of the terminal inclined portion connected to the first region flat portion. Alternatively, the second region of the resin layer may have a second region flat portion disposed along the surface of the terminal flat portion and a second region inclined portion disposed along the surface of the terminal inclined portion connected to the second region flat portion. Alternatively, in the sealing process, the power generation element may be sealed inside the outer casing such that θ5 and θ6 satisfy θ5 > θ6. In the sealing process, θ5 may be an angle formed by the first region flat portion and a straight line obtained by extending the first region inclined portion, and θ6 may be an angle formed by the second region flat portion and a straight line obtained by extending the second region inclined portion.

[0011] In the battery manufacturing method of the first aspect of this disclosure, θ2 can be an angle formed by the outer surface of the flat portion of the resin layer and a straight line obtained by extending the outer surface of the inclined portion of the resin layer.

[0012] In the battery manufacturing method of the first aspect of this disclosure, the length in the width direction of the flat portion of the terminal may be 20% or more and 90% or less of the length in the width direction of the current collector terminal, or the length in the width direction of the inclined portion of the terminal may be 10% or more and 80% or less of the length in the width direction of the current collector terminal.

[0013] The battery of the second aspect of this disclosure includes: a power generation element; an outer casing housing the power generation element; a current collector terminal electrically connected to the power generation element and configured to extend outward from the outer casing; and a resin layer disposed along at least one surface of the current collector terminal in the thickness direction and disposed between the current collector terminal and the outer casing, the resin layer and the outer casing being thermally bonded, the current collector terminal having a terminal flat portion of constant thickness and a terminal inclined portion connected to the terminal flat portion and thinning outward in the width direction, the terminal inclined portion being disposed at at least one end in the width direction of the current collector terminal, the resin layer having a resin layer flat portion disposed along the surface of the terminal flat portion and a resin layer inclined portion connected to the resin layer flat portion and disposed along the surface of the terminal inclined portion, θ3 and θ4 satisfying θ3 > θ4, θ3 being an angle formed by the terminal flat portion and a straight line obtained by extending the terminal inclined portion, and θ4 being an angle formed by the resin layer flat portion and a straight line obtained by extending the resin layer inclined portion.

[0014] The battery of the third aspect disclosed herein includes: a power generation element; an outer casing housing the power generation element; a current collector terminal electrically connected to the power generation element and configured to extend outward from the outer casing; and a resin layer disposed along at least one surface of the current collector terminal in the thickness direction and disposed between the current collector terminal and the outer casing, the resin layer being thermally bonded to the outer casing, the current collector terminal having a terminal flat portion of constant thickness and a terminal inclined portion connected to the terminal flat portion and thinning in thickness towards the outer side in the width direction of the current collector terminal, the terminal inclined portion being disposed at at least one end in the width direction of the current collector terminal, and the resin layer having a length direction fused to the outer casing. The first region of the resin layer and the second region not fused to the outer body, the first region of the resin layer has a first region flat portion disposed along the surface of the terminal flat portion and a first region inclined portion disposed along the surface of the terminal inclined portion connected to the first region flat portion, the second region of the resin layer has a second region flat portion disposed along the surface of the terminal flat portion and a second region inclined portion disposed along the surface of the terminal inclined portion connected to the second region flat portion, θ5 and θ6 satisfy θ5>θ6, θ5 is the angle formed by the first region flat portion and the straight line obtained by extending the first region inclined portion, and θ6 is the angle formed by the second region flat portion and the straight line obtained by extending the second region inclined portion.

[0015] The fourth aspect of the battery intermediate disclosed herein includes: a power generation element; a current collector terminal electrically connected to the power generation element; and a resin layer disposed along at least one surface of the current collector terminal in the thickness direction. The current collector terminal has a flat portion of constant thickness and a tilted portion of thinner thickness connected to the flat portion and extending outward in the width direction. The tilted portion is disposed at at least one end of the current collector terminal in the width direction. The resin layer has a flat portion of resin layer disposed along the surface of the flat portion of the terminal and a tilted portion of resin layer disposed along the surface of the tilted portion of the terminal, wherein θ1 and θ2 satisfy θ1 > θ2, θ1 is an angle formed by the flat portion of the terminal and a straight line formed by extending the tilted portion of the terminal, and θ2 is an angle formed by the flat portion of resin layer and a straight line formed by extending the tilted portion of resin layer.

[0016] According to this disclosure, it is possible to suppress the generation of gaps between the current collector terminal and the outer casing, and to suppress poor heat sealing. Attached Figure Description

[0017] The features, advantages, and technical and industrial importance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals denote like parts, and in the drawings:

[0018] Figure 1 This is a flowchart of a battery manufacturing method according to one embodiment.

[0019] Figure 2 This is a perspective view of a battery 100 manufactured by a battery manufacturing method according to one embodiment.

[0020] Figure 3 This is an exploded 3D view of battery 100.

[0021] Figure 4 This is a perspective view that simply shows the arrangement of the resin layer 40 on the current collector terminal 30.

[0022] Figure 5 This is a three-dimensional view of the battery intermediate 90 manufactured through the configuration process S1.

[0023] Figure 6A Is Figure 5 The cross-sectional view obtained by cutting through VIA-VIA.

[0024] Figure 6B yes Figure 6A Anatomical view.

[0025] Figure 7A This is another embodiment of the collector terminal 30.

[0026] Figure 7B This is another embodiment of the collector terminal 30.

[0027] Figure 8A This diagram shows, in chronological order, the application of a heating rod 50 to heat-melt the resin layer 40 onto the current collector terminal 30.

[0028] Figure 8B This diagram shows, in chronological order, the application of a heating rod 50 to heat-melt the resin layer 40 onto the current collector terminal 30.

[0029] Figure 8C This diagram shows, in chronological order, the application of a heating rod 50 to heat-melt the resin layer 40 onto the current collector terminal 30.

[0030] Figure 9A This diagram shows, in chronological order, the process of using a heating rod 60 to thermally bond the resin layer 40 to the outer casing 20.

[0031] Figure 9B This diagram shows, in chronological order, the process of using a heating rod 60 to thermally bond the resin layer 40 to the outer casing 20.

[0032] Figure 9C This diagram shows, in chronological order, the process of using a heating rod 60 to thermally bond the resin layer 40 to the outer casing 20.

[0033] Figure 10A This is a schematic diagram of the sealing process using a battery intermediate with θ1≤θ2.

[0034] Figure 10B This is a cross-sectional view of a battery after the sealing process using a battery intermediate with θ1≤θ2.

[0035] Figure 11 This is a sectional view of the part where the resin layer 40 and the outer casing 20 are thermally bonded.

[0036] Figure 12 This is a 3D view of the area near the collector terminal 30 of battery 100.

[0037] Figure 13A Is Figure 12 Anatomical view of XIIIA-XIIIA cut (anatomical view of first region 40a).

[0038] Figure 13B Is Figure 12 Anatomical view of XIIIB-XIIIB section (anatomical view of region 40b). Detailed Implementation

[0039] [Battery manufacturing method]

[0040] The battery manufacturing method of this disclosure will be described with reference to a battery manufacturing method according to one embodiment. Figure 1 A flowchart of a manufacturing method according to one embodiment is shown. Additionally, in Figure 2 A perspective view of a battery 100 manufactured by a manufacturing method according to one embodiment is shown. Figure 3 An exploded perspective view of battery 100 is shown. Herein, in this specification, Figure 2 The x-direction is defined as the length direction (the length direction of battery 100), the y-direction as the width direction (the width direction of battery 100), and the z-direction as the thickness direction (the thickness direction of battery 100). The x, y, and z directions are orthogonal to each other.

[0041] One embodiment of the manufacturing method is a method for manufacturing a battery 100, the battery 100 comprising: a power generation element 10; an outer casing 20 housing the power generation element 10; and a current collector terminal 30 electrically connected to the power generation element 10 and configured to extend outward from the outer casing 20, wherein, as Figure 1 As described, the manufacturing method includes a configuration step S1, a receiving step S2, and a sealing step S3.

[0042] like Figure 3 As shown, one embodiment of the manufacturing method involves fabricating a battery 100 by depositing a predetermined resin layer 40 on the current collector terminal 30. The following describes each step.

[0043] <Configuration Process S1>

[0044] The configuration step S1 is a process of configuring a resin layer 40 along at least one surface of the current collector terminal 30 connected to the power generation element 10 in the thickness direction. The battery intermediate 90 can be manufactured by the configuration step S1.

[0045] exist Figure 4 A perspective view is shown in the figure, illustrating a simplified depiction of the resin layer 40 disposed on the current collector terminal 30. Figure 5 A perspective view of the battery intermediate 90 is shown. Furthermore, in... Figure 6A The text shows that in Figure 5 The cross-sectional view obtained by cutting VIA-VIA, in Figure 6B It shows Figure 6A Anatomical view.

[0046] (Power generation element 10)

[0047] The power generation element 10 can also be a power generation element of a chemical battery such as a lithium-ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery. Alternatively, the power generation element 10 can also be a power generation element of a physical battery such as a capacitor. Furthermore, the power generation element 10 can be either a stacked type or a wound type. Additionally, the power generation element 10 can be either a solid-state battery or a liquid-state battery. Hereinafter, a stacked type power generation element 10 for a lithium-ion secondary battery is illustrated. However, the power generation element disclosed herein is not limited to this.

[0048] The power generation element 10 consists of a positive electrode current collector foil, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector foil (hereinafter, sometimes collectively referred to as "electrode elements"). The electrode elements are stacked in the thickness direction. The number of each stacked electrode element is not particularly limited. In addition, the electrode elements can be stacked either in series or in parallel.

[0049] The power generation element 10 has a sheet-like shape, which is rectangular when viewed from above. However, the power generation element 10 is not particularly limited as long as it has a shape that can be housed inside the outer casing 20. Additionally, each current collector foil of the power generation element 10 may also have tabs for connection to each current collector terminal 30. Positive tabs are provided on each positive current collector foil and are electrically connected to the positive current collector terminal. Similarly, negative tabs are provided on each negative current collector foil and are electrically connected to the negative current collector terminal.

[0050] The positive and negative current collector foils are sheet-like metal foils. The metals constituting the positive and negative current collector foils are not particularly limited, but examples include Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, and stainless steel. Al can also be used as the metal constituting the positive current collector foil. Cu can also be used as the material constituting the negative current collector foil.

[0051] The positive and negative current collector foils may also have certain coatings (e.g., carbon coatings) on their surfaces for adjusting resistance. The thickness of the positive and negative current collector foils may, for example, be 0.1 μm or more and 1 mm or less.

[0052] The positive electrode active material layer is a sheet-like layer containing positive electrode active material. The positive electrode active material is not particularly limited to any material suitable for use in lithium-ion secondary batteries. Examples include various lithium-containing composite oxides such as lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, and spinel-type lithium compounds.

[0053] The positive electrode active material layer can also arbitrarily include conductive additives and binders. The binder is not particularly limited as long as it can be used in lithium-ion secondary batteries. Examples include butadiene rubber (BR), butyl rubber (IIR), acrylate butadiene rubber (ABR), and polyvinylidene fluoride (PVdF). The conductive additive is also not particularly limited as long as it can be used in lithium-ion secondary batteries. Examples include carbon materials such as acetylene black and Ketjen black, and metallic materials such as nickel, aluminum, and stainless steel.

[0054] In the case of a fully solid-state battery, the positive electrode active material layer can arbitrarily contain a solid electrolyte. The solid electrolyte is not particularly limited as long as it is suitable for use in lithium-ion secondary batteries. For example, it can be either an organic polymer electrolyte or an inorganic solid electrolyte. An inorganic solid electrolyte is preferred because it has higher ionic conductivity and better heat resistance compared to organic polymer electrolytes. The inorganic solid electrolyte can be either an oxide solid electrolyte or a sulfide solid electrolyte. A sulfide solid electrolyte is preferred. Examples of oxide solid electrolytes include lithium zirconium lanthanum oxide, LiPON, and Li... 1+X AlXGe 2-X(PO4)3, Li-SiO glass, Li-Al-SO glass, etc. Examples of sulfide solid electrolytes include Li2S-P2S5, Li2S-SiS2, LiI-Li2S-SiS2, LiI-Si2S-P2S5, Li2S-P2S5-LiI-LiBr, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, and Li2S-P2S5-GeS2.

[0055] The content of each component in the positive electrode active material layer can be appropriately set according to the purpose. Additionally, the surface of the positive electrode active material can also be coated with oxide layers such as lithium niobate, lithium titanate, or lithium phosphate. The thickness of the positive electrode active material layer can be, for example, 0.1 μm or more and 1 mm or less.

[0056] The negative electrode active material layer is a sheet-like layer containing negative electrode active material. The negative electrode active material is not particularly limited to any material suitable for use in lithium-ion secondary batteries. Examples include silicon and Si alloys, silicon-based active materials such as silicon oxide, carbon-based active materials such as graphite and hard carbon, various oxide-based active materials such as lithium titanate, and metallic lithium and lithium alloys.

[0057] The negative electrode active material layer may also arbitrarily contain conductive additives and binders. The conductive additives and binders can be appropriately selected from those suitable for use in the positive electrode active material layer. Furthermore, in the case where the battery 100 is an all-solid-state battery, the negative electrode active material layer may also arbitrarily contain a solid electrolyte. The solid electrolyte can be appropriately selected from those suitable for use in the positive electrode active material layer.

[0058] The content of each component in the negative electrode active material layer can be appropriately set according to the purpose. The thickness of the negative electrode active material layer can be, for example, greater than 0.1 μm and less than 1 mm.

[0059] In the case of an all-solid-state battery, the electrolyte layer is a sheet-like solid electrolyte layer. The solid electrolyte layer contains a solid electrolyte. The solid electrolyte can be appropriately selected from solid electrolytes suitable for use in the positive electrode active material layer. Additionally, the solid electrolyte layer may arbitrarily contain a binder. The binder can be appropriately selected from binders suitable for use in the positive electrode active material layer. The content of each component in the solid electrolyte layer can be appropriately set according to the purpose. The thickness of the solid electrolyte layer can, for example, be 0.1 μm or more and 1 mm or less.

[0060] In the case of a liquid-type battery, the electrolyte layer comprises an electrolyte and a separator. The electrolyte and separator are not particularly limited, as long as they are suitable for use in lithium-ion secondary batteries. Examples of separators include porous sheets (membranes) made of polyolefins such as polyethylene (PE) and polypropylene (PP). The thickness of the separator can be, for example, 0.1 μm or more and 1 mm or less. The electrolyte typically contains a non-aqueous solvent and a supporting salt. Examples of non-aqueous solvents include carbonates, ethers, esters, nitriles, sulfones, and lactones. Examples of supporting salts include LiPF6, LiBF4, lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(trifluoromethane)sulfonylimide (LiTFSI). The concentration of the supporting salt in the electrolyte is not particularly limited, but can be, for example, 0.5 mol / L or more and 5 mol / L or less. Additionally, any components such as gas generators, film-forming agents, dispersants, and thickeners can be added to the electrolyte.

[0061] (Collector 30)

[0062] The collector terminal 30 is electrically connected to the power generation element 10 and is configured to extend outward from the outer casing 20. The collector terminal 30 has a positive collector terminal and a negative collector terminal; the positive collector terminal is connected to a positive collector foil, and the negative collector terminal is connected to a negative collector foil. The configuration of the positive and negative collector terminals is not particularly limited; it can be as follows: Figure 2 The current collector terminals 30 can be arranged on the opposite side of the power generation element 10, or on the same side. The material of the current collector terminals 30 is not particularly limited and can be appropriately selected from the metals used for each current collector foil. For example, the current collector terminals 30 can also be made of the same metal as each current collector foil. The metal constituting the positive current collector terminal can also be Al. The metal constituting the negative current collector terminal can also be Cu.

[0063] The current collector terminal 30 has a flat terminal portion 31 of constant thickness and a sloped terminal portion 32 connected to the flat terminal portion 31 and thinning towards the outer side in the width direction. The sloped terminal portion 32 is formed at the width-direction end of at least one of the current collector terminals 30. Therefore, in the manufactured battery 100, it is difficult for a gap to be generated between the current collector terminal 30 and the outer casing 20. From the viewpoint of further improving the effect, the current collector terminal 30 may also have sloped terminal portions 32 at both ends in the width direction. Figure 6B The diagram shows a current collector terminal 30 with terminal inclined portions 32 at both ends in the width direction. Other embodiments of the current collector terminal 30 with terminal inclined portions 32 at both ends in the width direction can be listed. Figure 7A , Figure 7B The shape shown. Thus, the collector terminal 30 can have both Figure 6B A hexagonal cross-section as shown can also have Figure 7A The trapezoidal cross-section shown can also have Figure 7B An octagonal cross-section as shown. Alternatively, it can be as follows: Figure 6B , Figure 7B Thus, the two surfaces at the end of the current collector terminal 30 in the thickness direction have terminal inclined portions 32. As a result, the generation of voids can be further suppressed.

[0064] The length of the collector terminal 30 in the longitudinal direction is not particularly limited, as long as it is set appropriately. Similarly, the length of the collector terminal 30 in the width direction is not particularly limited, as long as it is set appropriately. The length of the flat portion 31 in the width direction can be 20% or more, or 90% or less, of the length of the collector terminal 30 in the width direction. The length of the inclined portion 32 in the width direction can be 10% or more, or 80% or less, of the length of the collector terminal 30 in the width direction. By ensuring that the lengths of the flat portion 31 and the inclined portion 32 in the width direction are within the above-mentioned ranges, the generation of voids can be further suppressed.

[0065] The thickness of the current collector terminal 30 (the thickness of the flat portion 31) is not particularly limited and can be relatively thick. For example, it can be 1 mm or more, or 5 mm or less. If the current collector terminal 30 is thick, a gap is more likely to be generated between the current collector terminal 30 and the outer casing 20. However, since the current collector terminal 30 has the aforementioned terminal tilt portion 32, the generation of gaps can be suppressed. In addition, combined with the effect of the resin layer 40 described later, the generation of gaps can be further suppressed.

[0066] (Resin layer 40)

[0067] The resin layer 40 is disposed along at least one surface of the current collector terminal 30 in the thickness direction. For example... Figure 5 , Figure 6A , Figure 6B As shown, the resin layer 40 can also be disposed on both surfaces along the thickness direction of the current collector terminal 30. Since the resin layer 40 is a component that is heat-fused to the outer casing 20, it is made of a thermoplastic resin. Examples include crystalline resins such as polyethylene (PE) and polypropylene (PP), polyesters such as polyethylene terephthalate (PET), and non-crystalline resins such as polystyrene and polyvinyl chloride. The length of the resin layer 40 in the width direction only needs to be longer than the length of the current collector terminal 30 in the width direction. Furthermore, the length of the resin layer 40 in the length direction only needs to be longer than the length of the area to be heat-fused.

[0068] The resin layer 40 has a resin layer flat portion 41 disposed along the surface of the terminal flat portion 31 and a resin layer inclined portion 42 disposed along the surface of the terminal inclined portion 32 and connected to the resin layer flat portion 41. Alternatively, the resin layer 40 may also have a resin layer end portion 43 connected to the resin layer inclined portion 42.

[0069] The thickness of the resin layer 40 is not particularly limited, and a resin layer thicker than approximately 100 μm is used. For example, the thickness of the resin layer 40 can be 250 μm or more, or 400 μm or less. The reason for making the resin layer 40 relatively thick is to ensure that θ1 and θ2, described later, satisfy θ1 > θ2. In other words, it is to make the inclination of the inclined portion 42 of the resin layer gentler than the inclination of the inclined portion 32 of the terminal. As a result, the thickness of the inclined portion 42 of the resin layer increases towards the outer side in the width direction.

[0070] (Configuration process S1)

[0071] like Figure 6B As shown, the configuration step S1 is characterized in that: when the angle formed by the straight line obtained by extending the terminal flat portion 31 and the terminal inclined portion 32 is set as θ1, and the angle formed by the straight line obtained by extending the resin layer flat portion 41 and the resin layer inclined portion 42 is set as θ2, the resin layer 40 is configured on the current collector terminal 30 such that θ1 and θ2 satisfy θ1 > θ2. θ2 is the angle of the outer surface of the resin layer 40. When θ1 and θ2 are θ1 ≤ θ2, in the sealing step S3 described later, due to manufacturing tolerances, a gap may occur between the current collector terminal 30 and the outer casing 20. Manufacturing tolerances refer to tolerances such as the positional offset of the heating rod, the size of the heating rod, and the size of the current collector terminal in the sealing step S3. In contrast, by ensuring that θ1 and θ2 satisfy θ1 > θ2 after the configuration step S1, the generation of gaps can be suppressed even if manufacturing tolerances occur in the sealing step S3. This effect will be explained in detail in the sealing step S3 described later.

[0072] θ1 and θ2 only need to satisfy θ1 > θ2, and are not specifically limited. For example, θ1 can be greater than 30° or less than 60°. θ2 can be greater than 10° or less than 40°. In addition, the difference between θ1 and θ2 can be greater than 10° or less than 30°.

[0073] The method of disposing the resin layer 40 on the current collector terminal 30 such that θ1 > θ2 is not particularly limited, and for example, the following configurations can be listed. The following method can be listed: First, the current collector terminal 30 and the resin layer 40 are formed such that θ1 > θ2, and then... Figure 4 A resin layer 40 is disposed along the surface of the collector terminal 30 as shown.

[0074] Alternatively, a method can be described using a heating rod 50 to thermally melt the resin layer 40 onto the current collector terminal 30. Figures 8A to 8C The image shows, in chronological order, the application of a heating rod 50 to heat-melt the resin layer 40 onto the current collector terminal 30. For example... Figure 8A As shown, a resin layer 40 is disposed on the outside of the current collector terminal 30, and a heating rod 50 is disposed on the outside of the resin layer 40. Next, as... Figure 8B As shown, two heating rods 50 are used to clamp and heat the current collector terminal 30 and the resin layer 40. This allows the resin layer 40 to be tightly disposed on the current collector terminal 30. Furthermore, the ends 43 of the resin layers are heat-fused together, fixing the resin layer 40 to the current collector terminal 30. Then, as... Figure 8C As shown, the heating rod 50 is removed from the resin layer 40. In this way, by further clamping the current collector terminal 30 held by the resin layer 40 with the heating rod 50, the resin layer 40 can be disposed on the current collector terminal 30.

[0075] Here, the shape of the heating rod 50 is set such that θ2 of the resin layer 40 is a predetermined angle. The heating rod 50 has a flat portion 51 of constant thickness and a tilted portion 52 connected to the flat portion 51. The flat portion 51 corresponds to the flat portion 41 of the resin layer, and the tilted portion 52 corresponds to the tilted portion 42 of the resin layer. Furthermore, when the angle formed by the straight line obtained by extending the flat portion 51 and the tilted portion 52 is defined as θx, the shape of the heating rod 50 is set such that θx = θ2. θx is the angle of the inner surface of the heating rod 50. By using such a heating rod 50, it is possible to shape θ2 of the resin layer 40 into a predetermined angle and place the resin layer 40 on the current collector terminal 30. In addition, the heating rod 50 may also have a heating rod end 53 connected to the tilted portion 52. The heating rod end 53 corresponds to the resin layer end 43.

[0076] In addition, Figures 8A to 8C In this process, a pre-formed resin layer 40 is used, but the resin layer 40 that can be used in the preparation step S1 is not limited to this; a flat resin layer can also be used. This is because even if a flat, sheet-like resin layer is used, it can be shaped into the desired shape using the heating rod 50.

[0077] The temperature of the heating rod 50 is not particularly limited and can be appropriately set according to the melting temperature of the resin layer 40. For example, it can be above 150°C or below 200°C. Furthermore, the pressure of the heating rod 50 when clamping the current collector terminal 30 and the resin layer 40 is not particularly limited, as long as the current collector terminal 30 and the resin layer 40 can be properly heat-fused together. Additionally, it can be as long as the resin layer 40 can be shaped into the desired form. For example, it can be above 0.1 MPa or below 1 MPa. The heating rod 50 can be, for example, a known heating rod made of silicone rubber.

[0078] <Containment Procedure S2>

[0079] The housing process S2 is the process of housing the power generation element 10, on which the resin layer 40 is disposed, within the outer casing 20. At this time, the power generation element 10 is housed within the outer casing 20 such that the current collector terminal 30 extends outward from the outer casing 20. Furthermore, the outer casing 20 is positioned such that the resin layer 40 is disposed between the current collector terminal 30 and the outer casing 20. This is so that the resin layer 40 and the outer casing 20 can be thermally bonded together in the sealing process S3, which will be described later.

[0080] (outer body 20)

[0081] The outer casing 20 uses an outer casing with a heat-sealed layer. For example, a metal laminate can be cited. Generally, a metal laminate has a metal layer and a resin layer covering the metal layer.

[0082] The metal layer of the metal laminate functions as a gas barrier layer. The gas barrier layer is a layer that prevents moisture, air, or gases generated inside the battery 100 from entering or exiting. The metal layer can be made of metal materials such as aluminum, iron, or stainless steel.

[0083] A resin layer is provided on both sides of the metal layer, but the function of the resin layer differs depending on the side of the metal layer. For example, a heat-melting layer is used in the resin layer provided on the side where heat fusion is performed (usually the inner surface). The heat-melting layer contains a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene (PE) and polypropylene (PP), crystalline resins such as polyesters such as polyethylene terephthalate (PET), and non-crystalline resins such as polystyrene and polyvinyl chloride. On the other hand, a protective layer is used in the resin layer provided on the side where heat fusion is not performed (usually the outer surface). A resin that functions as a protective layer is appropriately used in the protective layer. Examples of resins include polyesters such as PET and polyamides (nylon).

[0084] When using a metal laminate as the outer casing 20, such as Figure 2 , Figure 3As shown, the power generation element 10 is held between two metal laminates. Alternatively, a single metal laminate is bent and the power generation element 10 is sandwiched between it. In this case, the metal laminates are arranged so that the heat-sealed layers overlap each other. Furthermore, the metal laminates may also have protrusions for housing the power generation element 10. These protrusions can be provided on both metal laminates or on one of them. This method allows the power generation element 10 to be housed within the outer casing 20.

[0085] The end of the outer casing 20 on the collector terminal 30 side can also be like... Figure 9A The outer casing is shaped as shown. In this case, the end of the outer casing 20 on the side of the current collector terminal 30 may also have an outer casing flat portion 21 and an outer casing inclined portion 22 connected to the outer casing flat portion 21. The outer casing flat portion 21 is the portion corresponding to the resin layer flat portion 41, and the outer casing inclined portion 22 is the portion corresponding to the resin layer inclined portion 42. In addition, the end of the outer casing 20 on the side of the current collector terminal 30 may also have an outer casing end portion 23 connected to the outer casing inclined portion 22. The outer casing end portion 23 is the portion corresponding to the resin layer end portion 43.

[0086] (Sealing process S3)

[0087] Sealing process S3 is a process of sealing the power generation element 10 inside the outer casing 20 by heat fusion. Specifically, it is a process of heat fusion bonding the ends of the outer casing 20 to seal the power generation element 10 inside the outer casing 20. At this time, since the resin layer 40 is disposed between the current collector terminal 30 and the outer casing 20, the resin layer 40 and the outer casing 20 are heat fused together in sealing process S3.

[0088] The heat fusion of the outer casing 20 can be carried out by known methods, but the heat fusion of the resin layer 40 and the outer casing 20, that is, the heat fusion of the end of the outer casing 20 on the side of the current collector terminal 30, uses a heating rod 60 with an angle.

[0089] exist Figures 9A to 9C The image shows, in chronological order, the application of a heating rod 60 to thermally fuse the resin layer 40 to the outer casing 20. For example... Figure 9A As shown, an outer casing 20 is disposed on the outside of the current collector terminal 30, on which the resin layer 40 is disposed, and a heating rod 60 is disposed on the outside of the outer casing 20. Next, as... Figure 9B As shown, two heating rods 60 are used to clamp and heat the end of the outer casing 20 on the side of the current collector terminal 30. This heat-fuses the resin layer 40 disposed on the current collector terminal 30 to the outer casing 20. Furthermore, the portion of the outer casing 20 disposed on the outer side in the width direction compared to the end of the resin layer 40 is heat-fuses to each other. Then, as... Figure 9CAs shown, the heating rod 60 is removed from the outer casing 20. In this way, by using the heating rod 60 to clamp the end of the outer casing 20 on which the current collector terminal 30 is disposed, the resin layer 40 is thermally bonded to the outer casing 20.

[0090] Similar to heating rod 50, heating rod 60 includes a flat portion 61 of constant thickness and a tilted portion 62 connected to the flat portion 61. The flat portion 61 corresponds to the flat portion 21 of the outer casing, and the tilted portion 62 corresponds to the tilted portion 22 of the outer casing. Furthermore, when the angle formed by the straight line extending from the flat portion 61 and the tilted portion 62 is defined as θy, the shape of heating rod 60 is set such that θ1 ≥ θy > θ2. θy is the angle of the inner surface of heating rod 60. By setting the angle to satisfy this relationship, it is difficult for a gap to be generated between the current collector 30 (resin layer 40) and the outer casing 20.

[0091] exist Figure 10A , Figure 10B The diagram shows a schematic of the sealing process using a battery intermediate with θ1≤θ2. Figure 10A Is with Figure 9A The corresponding diagram. (For example...) Figure 10A As shown, the position of the upper heating rod is offset from the specified position, resulting in a manufacturing tolerance d. When heat fusion is performed in this state, as... Figure 10B As shown by dashed line A, at the upper part of the inclined portion of the resin layer, the resin layer melts due to the heat from the heating rod and flows outward in the width direction, thus achieving thermal bonding with the outer casing. However, as shown by dashed line B, at the lower part of the inclined portion of the resin layer, a gap C is generated between the resin layer and the outer casing. Thus, when θ1≤θ2, gaps may occur due to manufacturing tolerances.

[0092] On the other hand, when θ1 > θ2, the resin layer inclined portion 42 has a structure in which the thickness increases towards the outer side in the width direction. Therefore, even if the manufacturing tolerances described above occur, the generation of voids can be suppressed in the portion of the resin layer inclined portion 42 on the outer side in the width direction.

[0093] Alternatively, the heating rod 60 may also have a heating rod end 63 connected to the heating rod inclined portion 62. This allows for the thermal fusion of the resin layer end 43 and the outer casing end 23, and also allows for the thermal fusion of the outer casing end 23 located at a position further outward than the resin layer end 43.

[0094] In addition, Figures 9A to 9CIn this process, an outer casing 20 with the end of the current collector terminal 30 side already formed is used. However, the end shape of the outer casing 20 that can be used in the sealing process S3 is not limited to this. An outer casing with a flat end can also be used. This is because even if such an outer casing is used, it can be shaped into the desired shape using the heating rod 60.

[0095] The temperature of the heating rod 60 is not particularly limited and can be appropriately set according to the heat-fusion temperature of the outer casing 20 and the resin layer 40. For example, it can be above 150°C or below 200°C. Furthermore, the pressure of the heating rod 60 when clamping the current collector terminal 30, the resin layer 40, and the outer casing 20 is not particularly limited, as long as the outer casing 20 and the resin layer 40 can be properly heat-fused. Additionally, it can be as long as the outer casing 20 can be formed into the desired shape. For example, it can be above 0.1 MPa or below 1 MPa. The heating rod 60 can be, for example, a known heating rod made of silicone rubber.

[0096] (Battery 100)

[0097] The battery 100 can be manufactured through the sealing process S3. As described above, the battery 100 suppresses the generation of voids. Such a battery 100 has the following structural features.

[0098] exist Figure 11 The diagram shows an exploded view of the portion where the resin layer 40 is thermally bonded to the outer casing 20 during the sealing process S3 of the battery 100. Additionally, only the internal metal layer 20a is shown in the outer casing 20 located on the upper side. Figure 11 As shown, the angle formed by the straight line obtained by extending the flat portion 31 of the terminal and the inclined portion 32 of the terminal is defined as θ3, and the angle formed by the straight line obtained by extending the flat portion 41 of the resin layer and the inclined portion 42 of the resin layer is defined as θ4. The relationship between θ3 and θ4 may vary depending on the conditions of the sealing process S3. This is because, in the sealing process S3, when the resin layer 40 is heat-fused to the resin layer disposed on the inner surface of the outer casing 20, the boundary between the resin layer 40 and the resin layer of the outer casing 20 is often unclear in the manufactured battery 100. Therefore, the angle of the inner surface of the metal layer 20a of the outer casing 20 can also be considered as θ4. Specifically, as... Figure 11 As shown, the angle of the inner surface of the metal layer 20a of the outer body 20, that is, the angle formed by the straight line obtained by extending the inner surface of the metal layer 20a of the flat portion 21 of the outer body and the inner surface of the metal layer 20a of the inclined portion 22 of the outer body, can also be regarded as θ4.

[0099] In the sealing process S3, when θy of the heating rod 60 satisfies θ1 > θy > θ2, θ3 and θ4 of the battery 100 satisfy θ3 > θ4. This is the same as the relationship between θ1 and θ2. However, there is a situation where, although θ1 and θ3 are approximately the same value, the values ​​of θ2 and θ4 are completely different. This is because, by using the heat-sealing of the heating rod 60, the resin layer 40 melts, and the angle formed by the straight line obtained by extending the flat portion 41 of the resin layer and the inclined portion 42 of the resin layer may change. Therefore, θ1 and θ3 are θ1 ≈ θ3, and θ2 and θ4 are θ4 ≥ θ2. In the case where the angle formed by the straight line obtained by extending the flat portion 41 of the resin layer and the inclined portion 42 of the resin layer changes, θ2 and θ4 are θ4 > θ2. Furthermore, when θ4 > θ2, the battery 100 has the following structural characteristics.

[0100] exist Figure 12 The image shows a perspective view obtained by cropping near a current collector terminal 30 of the battery 100. (See image for details.) Figure 12 As shown, the resin layer 40 has a first region 40a that is fused to the outer casing 20 and a second region 40b that is not fused to the outer casing 20 along its length. In other words, the first region 40a is the portion where the resin layer 40 is thermally fused to the outer casing 20 using the heating rod 60. In other words, the second region 40b is the portion where the resin layer 40 is not thermally fused to the outer casing 20 due to the absence of the heating rod 60.

[0101] Next, in Figure 13A The text shows that in Figure 12 Anatomical views of XIIIA-XIIIA sections (anatomical views of region 40a, first region), in Figure 13B The text shows that in Figure 12 Anatomical view of XIIIB-XIIIB section (anatomical view of region 40b).

[0102] like Figure 13A As shown, the first region 40a of the resin layer 40 includes a first region flat portion 41a disposed along the surface of the terminal flat portion 31 and a first region inclined portion 42a disposed along the surface of the terminal inclined portion 32 and connected to the first region flat portion 41a. Additionally, the first region 40a may also include a first region end portion 43a connected to the first region inclined portion 42a. Furthermore, as... Figure 13BAs shown, the second region 40b of the resin layer 40 includes a second region flat portion 41b disposed along the surface of the terminal flat portion 31 and a second region inclined portion 42b connected to the second region flat portion 41b and disposed along the surface of the terminal inclined portion 32. Additionally, the second region 40b may also include a second region end portion 43b connected to the second region inclined portion 42b. The first region flat portion 41a and the second region flat portion 41b correspond to the resin layer flat portion 41, the first region inclined portion 42a and the second region inclined portion 42b correspond to the resin layer inclined portion 42, and the first region end portion 43a and the second region end portion 43b correspond to the resin layer end portion 43.

[0103] Furthermore, when the angle formed by the straight line obtained by extending the first region flat portion 41a and the first region inclined portion 42a is defined as θ5, and the angle formed by the straight line obtained by extending the second region flat portion 41b and the second region inclined portion 42b is defined as θ6, θ5 and θ6 satisfy θ5 > θ6. In this case, θ5 corresponds to θ4, and θ6 corresponds to θ2. However, as described above, in the manufactured battery 100, the boundary between the resin layer 40 and the resin layer of the outer casing 20 is often unclear due to heat bonding. Therefore, the angle of the inner surface of the metal layer 20a of the outer casing 20 can also be considered as θ5. Specifically, as Figure 13A As shown, the angle of the inner surface of the metal layer 20a of the outer body 20 (shown only in the upper outer body 20) can also be regarded as θ5, that is, the angle formed by the inner surface of the metal layer 20a of the outer body flat portion 21 corresponding to the first region flat portion 41a and the inner surface of the metal layer 20a of the outer body inclined portion 22 corresponding to the first region inclined portion 42a.

[0104] On the other hand, in the sealing process S3, when the θy of the heating rod 60 satisfies θ1=θy>θ2, the θ3 and θ4 of the battery 100 sometimes become θ3=θ4. Even in such a case, θ5 and θ6 satisfy θ5>θ6.

[0105] Thus, the battery 100 manufactured by the sealing process S3 has a prescribed structural feature at the angle of the resin layer 40.

[0106] Here, θ3 can be, for example, greater than 30° or less than 60°. θ4 and θ5 can be greater than 10° or greater than 20°, less than 40° or less than 30°. θ6 can be greater than 10° or less than 40°. Furthermore, the difference between θ3 and θ4 can be greater than 10° or greater than 15°, less than 30° or less than 25°. The difference between θ5 and θ6 can be greater than 10° or greater than 15°, less than 30° or less than 25°.

[0107] In summary, when the θy of the heating rod 60 satisfies θ1 > θy > θ2, the power generation element 10 can be sealed to the outer casing 20 in the sealing process S3 such that θ3 and θ4 satisfy θ3 > θ4. On the other hand, when the θy of the heating rod 60 satisfies θ1 = θy > θ2, the power generation element 10 can be sealed to the outer casing 20 in the sealing process S3 such that θ5 and θ6 satisfy θ5 > θ6. However, other conditions of the heating rod 60 need to be set appropriately.

[0108] The battery manufacturing method of the present disclosure has been described above using one embodiment. According to the battery manufacturing method of the present disclosure, it is possible to minimize the generation of gaps between the current collector terminals and the outer casing.

[0109] [Battery Intermediate]

[0110] This disclosure provides a battery intermediate comprising: a power generation element; a current collector terminal electrically connected to the power generation element; and a resin layer disposed along at least one surface of the current collector terminal in the thickness direction. The current collector terminal has a flat portion of constant thickness and a sloped portion of thinner thickness connected to the flat portion and extending outward in the width direction. The sloped portion is formed at at least one end of the current collector terminal. The resin layer has a flat portion of resin layer disposed along the surface of the flat portion of the terminal and a sloped portion of resin layer disposed along the surface of the sloped portion of the terminal. When the angle formed by the flat portion of the terminal and the straight line obtained by extending the sloped portion of the terminal is defined as θ1, and the angle formed by the flat portion of the resin and the straight line obtained by extending the sloped portion of the resin is defined as θ2, θ1 and θ2 satisfy θ1 > θ2.

[0111] The battery intermediate disclosed herein can be manufactured using the configuration step in the battery manufacturing method of this disclosure. According to the battery intermediate of this disclosure, gaps between the current collector and the outer casing can be suppressed when the battery intermediate is sealed to the outer casing, and poor heat sealing can be suppressed. Since a detailed description of the battery intermediate of this disclosure has been described above, it is omitted here.

[0112] [Battery]

[0113] This disclosure provides a battery comprising: a power generation element; an outer casing housing the power generation element; a current collector terminal electrically connected to the power generation element and configured to extend outward from the outer casing; and a resin layer disposed along at least one surface of the current collector terminal in the thickness direction and disposed between the current collector terminal and the outer casing, the resin layer and the outer casing being thermally bonded together, the current collector terminal having a terminal flat portion of constant thickness and a terminal inclined portion connected to the terminal flat portion and thinning outward in the width direction, the terminal inclined portion being formed at at least one end of the current collector terminal, the resin layer having a resin layer flat portion disposed along the surface of the terminal flat portion and a resin layer inclined portion connected to the resin layer flat portion and disposed along the surface of the terminal inclined portion, wherein when the angle formed by the straight line obtained by extending the terminal flat portion and the terminal inclined portion is defined as θ3, and the angle formed by the straight line obtained by extending the resin layer flat portion and the resin layer inclined portion is defined as θ4, θ3 and θ4 satisfy θ3 > θ4.

[0114] Additionally, this disclosure provides a battery comprising: a power generation element; an outer casing housing the power generation element; a current collector terminal electrically connected to the power generation element and configured to extend outward from the outer casing; and a resin layer disposed along at least one surface of the current collector terminal in the thickness direction and disposed between the current collector terminal and the outer casing, the resin layer being thermally bonded to the outer casing, the current collector terminal having a terminal flat portion of constant thickness and a terminal inclined portion connected to the terminal flat portion and thinning outward in the width direction, the terminal inclined portion being formed at at least one end of the current collector terminal, and the resin layer having a first region fused to the outer casing in the length direction. The first region of the resin layer includes a first region flat portion disposed along the surface of the terminal flat portion and a first region inclined portion disposed along the surface of the terminal inclined portion connected to the first region flat portion. The second region of the resin layer includes a second region flat portion disposed along the surface of the terminal flat portion and a second region inclined portion disposed along the surface of the terminal inclined portion connected to the second region flat portion. When the angle formed by the first region flat portion and the straight line obtained by extending the first region inclined portion is set as θ5, and the angle formed by the second region flat portion and the straight line obtained by extending the second region inclined portion is set as θ6, θ5 and θ6 satisfy θ5 > θ6.

[0115] The battery disclosed herein can be manufactured using the battery manufacturing method of the disclosed invention. According to the battery of the disclosed invention, gaps generated between the current collector terminal and the outer casing can be suppressed, and poor heat sealing can be suppressed. Since the detailed description of the battery of the disclosed invention has been described above, it is omitted here.

Claims

1. A method of manufacturing a battery, the battery comprising: a power generation element; an outer casing housing the power generation element; and a current collector terminal electrically connected to the power generation element and configured to extend outward from the outer casing, characterized in that, The method for manufacturing the battery includes: In the configuration process, a resin layer is disposed along at least one surface of the current collector terminal connected to the power generation element in the thickness direction; The housing process, in which the power generation element is housed within the outer casing; and In the sealing process, the power generation element is sealed inside the outer casing by heat fusion. In the sealing process, the resin layer is heat-fused to the outer casing. The current collector terminal has a flat portion with a constant thickness and an inclined portion connected to the flat portion and thinning outward in the width direction of the current collector terminal. The inclined portion of the terminal is disposed at at least one end in the width direction of the current collector terminal. The resin layer has a resin layer flat portion disposed along the surface of the terminal flat portion and a resin layer inclined portion disposed along the surface of the terminal inclined portion and connected to the resin layer flat portion. In the configuration process, the thickness of the inclined portion of the resin layer increases outward toward the width direction of the current collector terminal, and the resin layer is configured on the current collector terminal such that θ1 and θ2 satisfy θ1 > θ2. In the configuration process, θ1 is the angle formed by the outer surface of the flat portion of the terminal and the straight line obtained by extending the outer surface of the inclined portion of the terminal, and θ2 is the angle formed by the straight line obtained by extending the outer surface of the flat portion of the resin layer and the straight line obtained by extending the outer surface of the inclined portion of the resin layer. The resin layer has a first region fused to the outer casing and a second region not fused to the outer casing along its length. The first region of the resin layer includes a first region flat portion disposed along the surface of the terminal flat portion and a first region inclined portion disposed connected to the first region flat portion and disposed along the surface of the terminal inclined portion. The second region of the resin layer includes a second region flat portion disposed along the surface of the terminal flat portion and a second region inclined portion connected to the second region flat portion and disposed along the surface of the terminal inclined portion. In the sealing process, the power generation element is sealed inside the outer casing such that θ5 > θ6. In the sealing process, θ5 is the angle formed by the outer surface of the flat portion of the first region and the straight line obtained by extending the outer surface of the inclined portion of the first region, and θ6 is the angle formed by the outer surface of the flat portion of the second region and the straight line obtained by extending the outer surface of the inclined portion of the second region.

2. The method for manufacturing a battery according to claim 1, characterized in that, In the sealing process, the power generation element is sealed inside the outer casing such that θ3 > θ4. In the sealing process, θ3 is the angle formed by the outer surface of the flat portion of the terminal and the straight line obtained by extending the outer surface of the inclined portion of the terminal, and θ4 is the angle formed by the straight line obtained by extending the outer surface of the flat portion of the resin layer and the straight line obtained by extending the outer surface of the inclined portion of the resin layer.

3. The method for manufacturing a battery according to claim 1, characterized in that, In the sealing process, a heating rod is used to heat-melt the resin layer to the outer casing. The outer casing has a portion corresponding to the flat portion of the resin layer, namely the flat portion of the outer casing, and a portion corresponding to the inclined portion of the resin layer, namely the inclined portion of the outer casing. The heating rod has a portion corresponding to the flat portion of the outer casing, namely the flat portion of the heating rod, and a portion corresponding to the inclined portion of the outer casing, namely the inclined portion of the heating rod. The relationship θ1≥θy>θ2 must be satisfied. θy is the angle formed by the inner surface of the flat portion of the heating rod and the straight line obtained by extending the inner surface of the inclined portion of the heating rod.

4. The method for manufacturing a battery according to claim 2, characterized in that, In the sealing process, a heating rod is used to heat-melt the resin layer to the outer casing. The outer casing has a portion corresponding to the flat portion of the resin layer, namely the flat portion of the outer casing, and a portion corresponding to the inclined portion of the resin layer, namely the inclined portion of the outer casing. The heating rod has a portion corresponding to the flat portion of the outer casing, namely the flat portion of the heating rod, and a portion corresponding to the inclined portion of the outer casing, namely the inclined portion of the heating rod. The relationship θ1≥θy>θ2 must be satisfied. θy is the angle formed by the inner surface of the flat portion of the heating rod and the straight line obtained by extending the inner surface of the inclined portion of the heating rod.

5. The method for manufacturing a battery according to any one of claims 1 to 4, characterized in that, The length of the flat portion of the terminal in the width direction is more than 20% and less than 90% of the length of the current collector terminal in the width direction. The length of the inclined portion of the terminal in the width direction is more than 10% and less than 80% of the length of the collector terminal in the width direction.

6. A battery, characterized in that, The battery is manufactured by the battery manufacturing method according to any one of claims 1 to 5.

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