Battery and manufacturing method for battery

Abstract

To provide a battery in which, even in the application of a load on a current collecting terminal, the deformation of a laminate film can be suppressed.SOLUTION: A battery includes an electrode body, a current collecting terminal disposed on a side surface part of the electrode body, and a laminate film covering the electrode body. The electrode body includes a current collecting tab connected to the current collecting terminal. When the battery is viewed in a side view from the current collecting terminal side, an outer edge of the current collecting terminal exists on the inside relative to an outer edge of the electrode body. The laminate film is disposed so as to cover a surface of the current collecting terminal that forms the outer edge and a surface of the electrode body that forms the outer edge. At a corner part of the current collecting terminal, a predetermined welding part in which inner surfaces of the laminate film are welded is disposed. The laminate film has a predetermined inclined surface continuously formed from a first surface at a position adjacent to an end part of the welding part on the electrode body side. The object can be achieved by the provision of such a battery.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to batteries and methods for making batteries. [Background technology]

[0002] Batteries such as lithium ion secondary batteries usually include an electrode body having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector. The electrode body is sealed in an internal space surrounded by an exterior material, for example. Patent Document 1 discloses a lithium polymer secondary battery including an electrode assembly, an exterior material surrounding the outside of the electrode assembly, and first and second covers sealing the exterior material, in which the first electrode terminal and the second electrode terminal are drawn out to the outside through the first cover and the second cover, respectively. Patent Document 1 also discloses a laminate film as the exterior material. Patent Document 2 discloses a battery using an exterior body made of one film, in which a rib structure is provided at the corner of the side perpendicular to the end face on which the current collecting tab lead is extended, in which a plurality of the above films are stacked. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-108623 A [Patent Document 2] Patent Publication No. 2021-190281 Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in FIG. 3 described later, the dimensions of the current collecting terminal may be smaller than the dimensions of the electrode body. If a current collecting terminal having such a dimensional relationship is sealed with a laminate film, wrinkles may occur in the laminate film, for example, and the sealing performance of the battery may be reduced. To solve this problem, the inventors came up with the idea of ​​providing a fused portion on the current collecting terminal, where the inner faces of the laminate film are fused together. By providing the fused portion, the deterioration of the sealing performance can be suppressed.

[0005] On the other hand, the electrode body usually has a current collecting tab for connection to a current collecting terminal. Since the current collecting tab has low rigidity, when a load is applied to the current collecting terminal, the laminate film (especially the laminate film located in the vicinity of the current collecting tab) is likely to deform.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and has as its main object to provide a battery that can suppress deformation of a laminate film even when a load is applied to a current collecting terminal. [Means for solving the problem]

[0007] [1] A battery comprising an electrode body, a current collecting terminal arranged on a side portion of the electrode body, and a laminate film covering the electrode body, wherein the electrode body has a current collecting tab connected to the current collecting terminal, and when the battery is viewed from the side from the current collecting terminal side, an outer edge of the current collecting terminal is located inside the outer edge of the electrode body, the laminate film is arranged to cover a surface constituting the outer edge of the current collecting terminal and a surface constituting the outer edge of the electrode body, and a fused portion in which inner surfaces of the laminate film are fused to each other is arranged at a corner of the current collecting terminal, and the fused portion has a first surface and a second surface facing the first surface and positioned outside the first surface, and a curved surface connecting the first surface and the second surface, wherein a normal direction of the first surface and a normal direction of the second surface are each parallel to a thickness direction of the battery, the fused portion extends from an end position of the laminate film on the current collecting terminal side toward the electrode body side, and the laminate film has an inclined surface formed continuously from the first surface at a position adjacent to the end portion of the fused portion on the electrode body side, and the normal direction of the inclined surface intersects with the thickness direction of the battery.

[0008] [2] The battery according to [1] or [2], wherein the inclined surface has a triangular shape when viewed in a plan view.

[0009] [3] The battery according to [1] or [2], wherein when the battery is viewed from the side of the collector terminal, the shape of the collector terminal is rectangular.

[0010] [4] The battery according to [3], wherein the fused portion is disposed at each of the four corners of the current collecting terminal.

[0011] [5] The battery according to any one of [1] to [4], wherein, when the battery is viewed from the side of the collector terminal, a ratio (L2 / L1) of the length L2 of the outer edge of the collector terminal to the length L1 of the outer edge of the electrode body is 0.7 or more and less than 1.

[0012] [6] A method for manufacturing a battery according to any one of [1] to [5], comprising: a preparation step of preparing a structure having the electrode body and the current collecting terminal; a first covering step of covering a surface of the structure that constitutes the outer edge of the electrode body with the laminate film; and a second covering step of covering a surface of the structure that constitutes the outer edge of the current collecting terminal with the laminate film, wherein in the second covering step, the fused portion is formed using a tool that can come into surface contact with the surface that constitutes the outer edge of the current collecting terminal, and a laminate film having a folding portion for forming the inclined surface is used as the laminate film. Effect of the Invention

[0013] The battery according to the present disclosure has an advantage that deformation of the laminate film can be suppressed even when a load is applied to the current collecting terminal. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic perspective view illustrating an electrode body and a current collecting terminal according to the present disclosure. [Diagram 2] FIG. 2 is a schematic perspective view illustrating an electrode body, a current collecting terminal, and a laminate film according to the present disclosure. [Diagram 3] 1A and 1B are a schematic side view and a schematic cross-sectional view illustrating an electrode body, a current collecting terminal, and a laminate film according to the present disclosure. [Figure 4] FIG. 2 is a schematic side view illustrating a portion of a battery in the present disclosure. [Diagram 5] FIG. 2 is a schematic side view illustrating a portion of a battery in the present disclosure. [Figure 6] FIG. 2 is a schematic plan view illustrating a portion of a battery according to the present disclosure. [Figure 7] FIG. 1 is a schematic perspective view illustrating a portion of a battery according to the present disclosure. [Figure 8] FIG. 1 is a schematic perspective view illustrating a portion of a battery according to the present disclosure. [Figure 9]FIG. 4 is an explanatory diagram illustrating a normal direction of an inclined surface in the present disclosure. [Figure 10] FIG. 2 is a schematic side view illustrating a second coating step in the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Each of the drawings shown below is a schematic illustration, and the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, in this specification, when expressing an aspect in which another member is arranged relative to a certain member, the term "above" or "below" is used, unless otherwise specified, it includes both a case in which another member is arranged directly above or below a certain member so as to be in contact with the certain member, and a case in which another member is arranged above or below a certain member via another member.

[0016] A.Battery FIG. 1 is a schematic perspective view illustrating an electrode body and a current collecting terminal in the present disclosure. The electrode body 10 shown in FIG. 1(a) has a top surface portion 11, a bottom surface portion 12 facing the top surface portion 11, and four side surfaces (a first side surface portion 13, a second side surface portion 14, a third side surface portion 15, and a fourth side surface portion 16) connecting the top surface portion 11 and the bottom surface portion 12. In FIG. 1(b), a first current collecting terminal 20A is disposed on the first side surface portion 13 of the electrode body 10, and a second current collecting terminal 20B is disposed on the third side surface portion 15 of the electrode body 10. For example, the first current collecting terminal 20A is a positive electrode current collecting terminal, and the second current collecting terminal 20B is a negative electrode current collecting terminal.

[0017] 2 is a schematic perspective view illustrating an electrode body, a current collecting terminal, and a laminate film according to the present disclosure. As shown in FIG. 2(a), the laminate film 30 is, for example, a single film. As shown in FIGS. 2(a) and 2(b), the laminate film 30 is folded so as to entirely cover the bottom surface portion 12, the second side surface portion 14, the top surface portion 11, and the fourth side surface portion 16 of the electrode body 10. Meanwhile, in FIG. 2(b), at least a part of the first current collecting terminal 20A and at least a part of the second current collecting terminal 20B are located inside the folded laminate film 30.

[0018] Fig. 3(a) is a schematic side view illustrating an electrode body and a current collecting terminal in the present disclosure, and Fig. 3(b) is a cross-sectional view taken along line AA of Fig. 3(a). As shown in Figs. 3(a) and (b), when the electrode body 10 and the current collecting terminal 20 are observed from the current collecting terminal 20 side, the outer edge E2 of the current collecting terminal 20 is located inside the outer edge E1 of the electrode body 10. In other words, the dimensions of the current collecting terminal 20 are smaller than the dimensions of the electrode body 10. Also, as shown in Fig. 3(b), the electrode body 10 has a side surface SS 10 The current collecting tab T is disposed on the surface facing the current collecting terminal 20 (side surface SS of the electrode body 10). 10 The two surfaces are joined together at the opposite ends of the plate.

[0019] FIG. 3(c) is a schematic side view illustrating the electrode body, the current collecting terminal, and the laminate film in the present disclosure, and FIG. 3(d) is a cross-sectional view taken along the line AA in FIG. 3(c). As shown in FIGS. 3(c) and (d), when the electrode body 10, the current collecting terminal 20, and the laminate film 30 are observed from the current collecting terminal 20 side, a space S is generated between the laminate film 30 and the current collecting terminal 20. Therefore, when the current collecting terminal 20 is sealed with the laminate film 30, wrinkles may occur in the laminate film 30 due to the excess part of the laminate film 30, and the sealing property of the battery may be reduced. In contrast, in the battery in the present disclosure, as shown in FIGS. 4(a) and (b), a fusion part X is arranged at the corner of the current collecting terminal 20, where the inner surfaces (surfaces on the current collecting terminal 20 side) of the laminate film 30 are fused together. By providing the fusion part X, the deterioration of the sealing property due to the wrinkles of the laminate film can be suppressed.

[0020] As shown in FIG. 5, the fused portion X is a And the second side S b And, the first side S a and the second surface S b The surface S that connects c The second surface S b is the first surface S a and in the thickness direction D of the battery T In the first surface S a It is located on the outer side. Also, the first surface S a Normal direction of and second surface S b The normal direction of is the thickness direction of the battery D T is parallel to

[0021] 6 and 7, when the battery 100 is viewed in plan from the thickness direction, the end position of the laminate film 30 on the current collecting terminal 20 side is designated as α. The fused portion X extends from the end position α toward the electrode body 10 side. Also, as shown in FIG. 8, the laminate film 30 has a first surface S at a position adjacent to the end of the fused portion X on the electrode body 10 side (the end opposite to the end position α). a The normal direction of the inclined surface Z is the thickness direction D of the battery. T , and is intersecting with respect to .

[0022] According to the present disclosure, since the fusion portion is disposed on the current collecting terminal, the battery suppresses the deterioration of the sealing property. As shown in FIG. 3 described above, the dimensions of the current collecting terminal may be smaller than the dimensions of the electrode body. By adopting such a dimensional relationship, for example, when a plurality of batteries are stacked, it is possible to prevent adjacent current collecting terminals from contacting each other. By preventing the contact of adjacent current collecting terminals, the battery is less likely to be damaged. In addition, when the current collecting terminals having such a dimensional relationship are sealed with a laminate film, for example, wrinkles may occur in the laminate film, and the sealing property of the battery may be reduced. In the present disclosure, by disposing the fusion portion X in which the inner surfaces of the laminate film are fused to each other on the current collecting terminal, the battery suppresses the deterioration of the sealing property even when the dimensions of the current collecting terminal are made smaller than the dimensions of the electrode body. On the other hand, as described above, the electrode body usually has a current collecting tab for connecting to the current collecting terminal. Since the current collecting tab has low rigidity, when a load is applied to the current collecting terminal, the laminate film located near the current collecting tab is likely to deform. In contrast, according to the present disclosure, by providing a predetermined inclined surface on the laminate film, a battery is obtained in which deformation of the laminate film located near the current collecting tab is suppressed even when a load is applied to the current collecting terminal.

[0023] 1. Battery configuration The battery according to the present disclosure includes at least an electrode body, a current collecting terminal, and a laminate film.

[0024] (1) Electrode body The electrode body in the present disclosure functions as a power generating element of a battery. The shape of the electrode body is not particularly limited, but for example, as shown in FIG. 1(a), the electrode body has a top surface portion 11, a bottom surface portion 12 facing the top surface portion 11, and four side surfaces (a first side surface portion 13, a second side surface portion 14, a third side surface portion 15, and a fourth side surface portion 16) connecting the top surface portion 11 and the bottom surface portion 12. The top surface portion 11 and the bottom surface portion 12 both correspond to the main surface of the electrode body, and the normal direction of the main surface can be defined as the thickness direction. In addition, the first side surface portion 13 and the third side surface portion 15 are arranged to face each other. Similarly, the second side surface portion 14 and the fourth side surface portion 16 are arranged to face each other.

[0025] The shape of the top surface portion is not particularly limited, and examples thereof include quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, a parallelogram, etc. The shape of the top surface portion 11 in Fig. 1(a) is a rectangle. The shape of the top surface may be a polygon other than a rectangle, or may be a shape having a curve such as a circle. The shape of the bottom surface is the same as that of the top surface. The shape of the side surface is not particularly limited, but examples thereof include quadrangles such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram.

[0026] (2) Current collector terminal The current collecting terminals in the present disclosure are disposed on the side surfaces of the electrode body. The battery in the present disclosure preferably includes two current collecting terminals for one electrode body. For example, as shown in FIG. 1(b), a pair of current collecting terminals 20 (a first current collecting terminal 20A and a second current collecting terminal 20B) may be disposed to face each other with respect to the electrode body 10. Also, in FIG. 1(b), the pair of current collecting terminals 20 are disposed to face each other in the longitudinal direction of the electrode body 10.

[0027] When the battery is viewed from the side of the collector terminal, the shape of the collector terminal is not particularly limited, but examples thereof include quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram. The shape of the collector terminal 20 in FIG. 3(a) is a rectangle. In this rectangle, the thickness direction D T The short side extends along a direction parallel to the thickness direction D T The long side extends along a direction perpendicular to the

[0028] When the battery is viewed from the side of the current collecting terminal, the outer edge of the current collecting terminal is located inside the outer edge of the electrode body. For example, as shown in Fig. 3(a), the outer edge E2 of the current collecting terminal 20 is located inside the outer edge E1 of the electrode body 10. In other words, the outer edge E2 of the current collecting terminal 20 is included in the outer edge E1 of the electrode body 10 over its entire circumference.

[0029] For example, in FIG. 3(a), the length (total circumferential length) of the outer edge E1 of the electrode body 10 is L1, and the length (total circumferential length) of the outer edge E2 of the current collecting terminal 20 is L2. The ratio of L2 to L1 (L2 / L1) may be, for example, 0.7 or more and less than 1, or 0.8 or more and 0.95 or less. T The length of the outer edge E1 at L a and the thickness direction D T The length of the outer edge E2 at L b Let us assume that L a L for b Percentage of (L b / L a ) may be, for example, 0.5 or more and less than 1, or 0.8 or more and 0.95 or less. T The length of the outer edge E1 in the direction perpendicular to L c and the thickness direction D T The length of the outer edge E2 in the direction perpendicular to L d Let us assume that L c L for d Percentage of (L d / L c ) may be, for example, 0.5 or more and less than 1, or 0.8 or more and 0.95 or less. Also, for example, in FIG. 3(a), the length of the gap between the outer edge E1 and the outer edge E2 is δ. δ is greater than 0 mm, and may be 0.3 mm or more, or 0.5 mm or more. On the other hand, δ is, for example, 1.5 mm or less.

[0030] (3) Laminate film The laminate film in the present disclosure covers the electrode body and seals the electrode body together with the current collecting terminal. As shown in FIG. 2, when the electrode body 10 and the current collecting terminal 20 are observed from the current collecting terminal 20 side, the laminate film 30 is arranged so as to cover the surface constituting the above-mentioned outer edge of the current collecting terminal 20 and the surface constituting the above-mentioned outer edge of the electrode body 10. Also, as shown in FIG. 4(a), a fusion part X in which the inner surfaces of the laminate film 30 are fused to each other is arranged at the corner of the current collecting terminal 20. It is preferable that the fusion surface in the fusion part X does not have a gap. The laminate film may have one fusion part X, or may have two or more fusion parts X. Also, the fusion part X may be arranged at each of two corners of the current collecting terminal that are opposed to each other in the thickness direction. Also, in FIG. 4(a), an end adhesion part Y in which the ends of the laminate film 30 are fused to each other is arranged. The end adhesion part Y may be folded to match the shape of the current collecting terminal. This is because it is possible to reduce excess space. Also, as shown in Fig. 4(b), the shape of the current collecting terminal 20 may be a rectangle, and the fused portion X may be disposed at each of the corners. In Fig. 4(b), the end contact portion Y is disposed on the side connecting two corners.

[0031] As shown in FIG. 5, the fused portion X is a And the second side S b And, the first side S a and the second surface S b The surface S that connects c The second surface S b is the first surface S a and in the thickness direction D of the battery T In the first surface S a It is located on the outer side. Also, the first surface S a Normal direction of and second surface S b The normal direction of is the thickness direction of the battery D T "Parallel" means that the angle between them is 20 degrees or less.

[0032] In Fig. 5, when the battery 100 is viewed from the side of the current collecting terminal 20, the fused portion X is disposed at a corner that constitutes the outer edge E2 of the current collecting terminal 20. Specifically, the corner that constitutes the outer edge E2 of the current collecting terminal 20 coincides with an end t of the fused surface of the fused portion X. Also, as shown in Fig. 5, the width of the fused surface of the fused portion X is w. The width w is, for example, 0.1 mm or more, may be 0.3 mm or more, or may be 0.6 mm or more. Meanwhile, the width w is, for example, 1.2 mm or less.

[0033] As shown in Figs. 6 and 7, when the battery 100 is viewed in plan from the thickness direction, the end position of the laminate film 30 on the side of the current collector terminal 20 is α, and the position of the laminate film 30 corresponding to the boundary between the current collector terminal 20 and the electrode body 10 is β. The fusion part X in Figs. 6 and 7 is continuously arranged from the end position α to the position β. In addition, when the direction (axial direction) in which the current collector terminal 20 extends from the electrode body 30 is D1, it is preferable that the fusion part X is arranged along D1. In addition, the fusion part X may be arranged in at least a part of the region from the end position α to the position β in D1. The length of the fusion part X in D1 is, for example, 1 mm or more, may be 3 mm or more, or may be 5 mm or more.

[0034] As shown in FIG. 8, the laminate film 30 has a first surface S at a position adjacent to the end of the fusion portion X on the electrode body 10 side (the end opposite to the end position α). a The normal direction of the inclined surface Z is the thickness direction D of the battery. T 8, the direction in which the current collecting terminal 20 extends from the electrode body 30 (axial direction) is defined as D1, and the thickness direction of the battery is defined as D2. The term "intersect" means that the angle between the two is greater than 20°. The inclined surface Z may be a flat surface or a curved surface. The normal direction of the inclined surface Z means the normal direction at the center of gravity of the inclined surface Z. As shown in FIG. 8, the direction in which the current collecting terminal 20 extends from the electrode body 30 (axial direction) is defined as D1, and the thickness direction of the battery is defined as D2. T The direction corresponding to D1 is defined as D3, and the direction perpendicular to D1 and D3 is defined as D2. FIG. 9 is an explanatory diagram for explaining the normal direction of the inclined surface Z1 in FIG. 8. As shown in FIG. 9(a), when the inclined surface Z is viewed from D1, the normal direction DZ It is preferable that the inclined surface Z is directed toward the outside (-D2 side) of the collector terminal. Also, as shown in FIG. 9(b), when the inclined surface Z is viewed from D2, the normal direction D Z It is preferable that the normal direction D1 points to the collector terminal side (+D1 side). Z It is preferable that the height component (D3 component) of the inclined surface Z2 in FIG. 8 points to the inside of the battery. Although not shown, in the case of the inclined surface Z2 in FIG. 8, the -D3 side corresponds to the inside of the battery, and the +D3 side corresponds to the outside of the battery. It is also preferable that the shape of the inclined surface in a plan view is triangular. A triangular shape does not only mean a strict triangle, but also includes a triangle in which at least one of the sides constituting the triangle is curved.

[0035] 2. Battery components The battery according to the present disclosure comprises an electrode body, a current collecting terminal, and a laminate film.

[0036] (1) Electrode body The electrode assembly in the present disclosure typically has a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector, in this order in the thickness direction.

[0037] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the positive electrode active material include oxide active materials. Examples of the oxide active material include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of the positive electrode active material include rock salt layer type active materials such as O2, spinel type active materials such as LiMn2O4, and olivine type active materials such as LiFePO4. Sulfur (S) may also be used as the positive electrode active material. The positive electrode active material may be, for example, in the form of particles.

[0038] Examples of the conductive material include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. The liquid electrolyte (electrolytic solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. Examples of the binder include a rubber-based binder and a fluoride-based binder.

[0039] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, Li4Ti5O 12 The oxide active material may be in the form of, for example, particles or foil. The conductive material, electrolyte and binder are the same as those described above.

[0040] The electrolyte layer is disposed between the positive electrode active material layer and the negative electrode active material layer, and contains at least an electrolyte. The electrolyte may be a solid electrolyte or a liquid electrolyte. The electrolyte is the same as that described above. The electrolyte layer may have a separator.

[0041] The positive electrode current collector collects the current from the positive electrode active material layer. Examples of the material of the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of the shape of the positive electrode current collector include a foil shape and a mesh shape. The positive electrode current collector may have a positive electrode tab for connecting to a positive electrode current collector terminal.

[0042] The negative electrode current collector collects the current from the negative electrode active material layer. Examples of the material for the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include a foil shape and a mesh shape. The negative electrode current collector may have a negative electrode tab for connecting to a negative electrode current collector terminal.

[0043] (2) Current collector terminal The current collecting terminal in the present disclosure is disposed on the side of the electrode body. The current collecting terminal refers to a terminal having a current collecting portion at least in a portion thereof. The current collecting portion is, for example, electrically connected to a tab in the electrode body. The current collecting terminal may be entirely the current collecting portion, or may be partially the current collecting portion. Examples of materials for the current collecting terminal include metals such as aluminum and SUS.

[0044] (3) Laminate film The laminate film in the present disclosure has at least a structure in which a heat-sealing layer and a metal layer are laminated. The laminate film may have a heat-sealing layer, a metal layer, and a resin layer in this order along the thickness direction. Examples of the material of the heat-sealing layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of the material of the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of the material of the resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the heat-sealing layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.

[0045] (4)Battery The battery in the present disclosure is typically a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, the battery is preferably used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for moving objects other than vehicles (e.g., railways, ships, and aircraft), or as a power source for electrical products such as information processing devices. The present disclosure may also provide a battery module in which a plurality of the above-mentioned batteries are stacked in the thickness direction.

[0046] B. Battery manufacturing method The manufacturing method of the battery in the present disclosure is a manufacturing method of the battery described above, which includes a preparation step of preparing a structure having the electrode body and the collector terminal, a first covering step of covering the surface that constitutes the outer edge of the electrode body in the structure with the laminate film, and a second covering step of covering the surface that constitutes the outer edge of the collector terminal in the structure with the laminate film, in which the fusion portion is formed using a jig that can make surface contact with the surface that constitutes the outer edge of the collector terminal, and a laminate film having a folding portion for forming the inclined surface is used as the laminate film.

[0047] According to the present disclosure, by forming a fused portion, a battery in which deterioration of sealing performance is suppressed can be obtained. Furthermore, by using a laminate film having a folded portion, it becomes easy to form an inclined surface.

[0048] 1. Preparation process The preparation step in the present disclosure is a step of preparing a structure having the electrode body and the current collector terminal. The electrode body and the current collector terminal are the same as those described in "A. Battery" above, so a description thereof will be omitted here.

[0049] 2. First coating process The first covering step in the present disclosure is a step of covering the outer edge of the electrode body in the structure with the laminate film. For example, as shown in Figs. 2(a) and (b), in the first covering step, the surfaces constituting the outer edge of the electrode body 10 (for example, the bottom surface portion 12, the second side surface portion 14, the top surface portion 11, and the fourth side surface portion 16) are covered with the laminate film 30. At this time, the electrode body 10 and the laminate film 30 may or may not be welded. In addition, as shown in Fig. 2(b), the end overlap portion Z where the ends of the laminate film 30 overlap is heated. As a result, an end adhesion portion Y where the ends of the laminate film 30 are fused together is formed. The laminate film may be previously folded to match the shape of the electrode body.

[0050] In the first covering step, a space S is usually formed between the laminate film 30 and the current collecting terminal 20, as shown in Fig. 3(c) and (d). This space S disappears in the second covering step described later, and a fused portion is formed instead.

[0051] 3. Second coating process The second covering step in the present disclosure is a step of covering the surface constituting the outer edge of the current collector terminal with the laminate film. In addition, in the second covering step, a fusion portion is formed. In addition, as the laminate film, a laminate film having a folding processing portion for forming an inclined surface is used.

[0052] In the second covering step, the current collecting terminal and the laminate film are welded together using a jig capable of surface contact with the surface constituting the outer edge of the current collecting terminal. FIG. 10 is a schematic side view illustrating the second covering step in the present disclosure. As shown in FIG. 10(a), a space S is formed between the laminate film 30 and the current collecting terminal 20 by the above-mentioned first covering step. In addition, an end contact portion Y is formed by the above-mentioned first covering step. Next, as shown in FIG. 10(b), jigs 41, 42, 43, and 44 are pressed into the laminate film 30 and the current collecting terminal 20. It is preferable that the jigs 41 to 44 are heated. In the thickness direction D, T In this case, the length of jigs 42 and 44 (the length in the vertical direction in the drawing) is shorter than the length of current collecting terminal 20 (the length in the vertical direction in the drawing). Therefore, a gap is generated between jigs 41 and 42, and the excess portion of laminate film 30 gathers in the gap. As a result, fused portion X is formed as shown in Fig. 10(c). In addition, in the present disclosure, the laminate film 30 having a folding part for forming the inclined surface is used, so that the inclined surface is stably formed.

[0053] 4.Battery The battery obtained by the above-mentioned steps is similar to that described above in "A. Battery," and therefore will not be described here.

[0054] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included in the technical scope of the present disclosure. [Explanation of symbols]

[0055] 10...Electrode body 11...Top part 12…Bottom part 13...First side part 14…Second side part 15…Third side part 16…Fourth side part 20...Current collector terminal 30...Laminating film 100...battery

Claims

1. An electrode body; A current collecting terminal disposed on a side surface of the electrode body; A laminate film covering the electrode body; A battery comprising: The electrode body has a current collecting tab connected to the current collecting terminal, When the battery is viewed from the side of the current collecting terminal, an outer edge of the current collecting terminal is located inside an outer edge of the electrode body, the laminate film is disposed so as to cover a surface constituting the outer edge of the current collecting terminal and a surface constituting the outer edge of the electrode body; A fusion portion in which inner surfaces of the laminate film are fused to each other is disposed on the current collecting terminal, the fusion portion has a first surface, a second surface facing the first surface and positioned outside the first surface, and a curved surface connecting the first surface and the second surface, the fusion portion extends from an end position of the laminate film on the current collecting terminal side toward the electrode body side, the laminate film has an inclined surface formed continuously from the first surface at a position adjacent to an end of the fusion portion on the electrode body side, A battery, wherein a normal direction of the inclined surface intersects with a thickness direction of the battery.

2. A battery as described in claim 1, wherein the planar shape of the inclined surface is triangular.

3. A battery as described in claim 1 or claim 2, wherein when the battery is viewed from the side from the collecting terminal side, the shape of the collecting terminal is rectangular.

4. A battery as described in claim 3, wherein the fused portion is disposed at each of the four corners of the collecting terminal.

5. The battery according to claim 1 or claim 2, wherein, when the battery is viewed from the side from the collecting terminal side, the ratio (L2 / L1) of the length L2 of the outer edge of the collecting terminal to the length L1 of the outer edge of the electrode body is 0.7 or more and less than 1.

6. A method for manufacturing a battery according to claim 1 or claim 2, comprising the steps of: a preparation step of preparing a structure having the electrode body and the current collecting terminal; a first covering step of covering a surface constituting the outer edge of the electrode body in the structure with the laminate film; A second covering step of covering a surface constituting the outer edge of the current collecting terminal in the structure with the laminate film, In the second covering step, the fusion portion is formed using a jig capable of surface-to-surface contact with a surface constituting the outer edge of the current collector terminal, The method for manufacturing a battery, wherein the laminate film has a folded portion for forming the inclined surface.

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