Battery and method for manufacturing the 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 manufacturing batteries. [Background technology]

[0002] Batteries such as lithium-ion secondary batteries typically include an electrode assembly having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector. The electrode assembly is sealed in an 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 exterior of the electrode assembly, and first and second covers sealing the exterior material, with the first electrode terminal and the second electrode terminal extending to the outside through the first cover and the second cover, respectively. Patent Document 1 also describes a laminate film as the exterior material. Patent Document 2 discloses a battery using an exterior material made of a single film, in which a rib structure made of multiple layers of the film is provided at the corners of the side perpendicular to the end face along which the current collecting tab lead extends. [Prior art documents] [Patent documents]

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

[0004] As shown in Figure 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 with such a dimensional relationship is sealed with a laminate film, wrinkles may occur in the laminate film, reducing the sealing performance of the battery. To solve this problem, the inventors came up with the idea of ​​providing a fused portion on the current collecting terminal, where the inner surfaces of the laminate film are fused together. By providing a fused portion, the reduction in sealing performance can be suppressed.

[0005] On the other hand, the electrode body usually has a current collecting tab for connecting to a current collecting terminal. Because 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 near the current collecting tab) is likely to deform.

[0006] The present disclosure has been made in consideration of the above-described 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 surface 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 that constitutes the outer edge of the current collecting terminal and a surface that constitutes the outer edge of the electrode body, and a fused portion where 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 outward of the first surface, and a curved surface connecting the first surface and the second surface, wherein the normal direction of the first surface and the normal direction of the second surface are each parallel to the thickness direction of the battery, the fused portion extends from an end position of the laminate film on the collector 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 of the fused portion on the electrode body side, and the normal direction of the inclined surface intersects the thickness direction of the battery.

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

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

[0010] [4] The battery according to [3], wherein the fused portion is disposed at each of the four corners of the current collector 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, the 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 collector 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 collector terminal with the laminate film, wherein in the second covering step, the fused portion is formed using a jig that can come into surface contact with the surface that constitutes the outer edge of the current collector terminal, and the laminate film is a laminate film that has a folded portion for forming the inclined surface. [Effects of the Invention]

[0013] The battery according to the present disclosure has the advantage of being able to suppress deformation of the laminate film even when a load is applied to the current collecting terminal. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic perspective view illustrating an electrode assembly and a current collecting terminal according to the present disclosure. [Figure 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. [Figure 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. 1 is a schematic side view illustrating a portion of a battery according to the present disclosure. [Figure 5] FIG. 1 is a schematic side view illustrating a portion of a battery according to the present disclosure. [Figure 6] FIG. 1 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. 2 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 INVENTION

[0015] Hereinafter, 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 for ease of understanding. Furthermore, in this specification, when expressing the manner in which another member is disposed relative to a certain member, the term "above" or "below" simply refers to both a case in which another member is disposed directly above or below the certain member so as to be in contact with the certain member, and a case in which another member is disposed above or below the certain member via another member, unless otherwise specified.

[0016] A.Battery Fig. 1 is a schematic perspective view illustrating an electrode assembly and current collecting terminals according to the present disclosure. The electrode assembly 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. Also, in Fig. 1(b), a first current collecting terminal 20A is disposed on the first side surface portion 13 of the electrode assembly 10, and a second current collecting terminal 20B is disposed on the third side surface portion 15 of the electrode assembly 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] 2A and 2B are schematic perspective views illustrating an electrode assembly, current collecting terminals, and laminate film according to the present disclosure. As shown in FIG. 2A, the laminate film 30 is, for example, a single film. As shown in FIGS. 2A and 2B, the laminate film 30 is folded so as to entirely cover the bottom surface 12, second side surface 14, top surface 11, and fourth side surface 16 of the electrode assembly 10. In FIG. 2B, at least a portion of the first current collecting terminal 20A and at least a portion 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 assembly and a current collecting terminal according to the present disclosure, and Fig. 3(b) is a cross-sectional view taken along the line AA in Fig. 3(a). As shown in Figs. 3(a) and 3(b), when the electrode assembly 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 assembly 10. In other words, the dimensions of the current collecting terminal 20 are smaller than the dimensions of the electrode assembly 10. Furthermore, as shown in Fig. 3(b), the electrode assembly 10 has a side surface SS 10 The current collecting tab T is provided on the surface facing the current collecting terminal 20 (the side surface SS of the electrode body 10). 10 The surfaces are joined together.

[0019] FIG. 3(c) is a schematic side view illustrating an electrode assembly, a current collecting terminal, and a laminate film according to the present disclosure, and FIG. 3(d) is a cross-sectional view taken along the line AA of FIG. 3(c). As shown in FIGS. 3(c) and 3(d), when the electrode assembly 10, the current collecting terminal 20, and the laminate film 30 are observed from the current collecting terminal 20 side, a space S is formed 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, excess portions of the laminate film 30 may cause wrinkles in the laminate film 30, which may reduce the sealing performance of the battery. In contrast, as shown in FIGS. 4(a) and 4(b), the battery according to the present disclosure has fused portions X at the corners of the current collecting terminal 20, where the inner surfaces of the laminate film 30 (the surfaces facing the current collecting terminal 20) are fused together. The provision of the fused portions X can prevent deterioration of sealing performance due to wrinkles in the laminate film.

[0020] As shown in FIG. 5, the fused portion X is a And, the second side S b And, first page S a and the second surface S b The surface S connecting 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. 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] As shown in Figures 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 collector 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 Figure 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 It intersects with.

[0022] According to the present disclosure, a fused portion is disposed on the current collecting terminal, resulting in a battery in which deterioration of sealing performance is suppressed. As shown in FIG. 3 above, the dimensions of the current collecting terminal may be smaller than the dimensions of the electrode assembly. By adopting such a dimensional relationship, for example, when multiple batteries are stacked, contact between adjacent current collecting terminals can be prevented. Preventing contact between adjacent current collecting terminals reduces the likelihood of battery damage. Furthermore, if current collecting terminals having such a dimensional relationship are sealed with a laminate film, wrinkles may occur in the laminate film, for example, which may reduce the sealing performance of the battery. In the present disclosure, by disposing a fused portion X, in which the inner surfaces of the laminate film are fused together, on the current collecting terminal, a battery in which deterioration of sealing performance is suppressed even when the dimensions of the current collecting terminal are smaller than the dimensions of the electrode assembly is obtained. Meanwhile, as described above, the electrode assembly typically has a current collecting tab for connection to the current collecting terminal. Because 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 surfaces of the electrode body, and the normal direction to the main surfaces can be defined as the thickness direction. 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 squares, rectangles, rhombuses, trapezoids, parallelograms, etc. The shape of the top surface portion 11 in Fig. 1(a) is rectangular. The shape of the top surface may be a polygon other than a rectangle, or may be a curved shape 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 quadrilaterals such as a square, rectangle, rhombus, trapezoid, and parallelogram.

[0026] (2) Current collector terminal The current collecting terminals in the present disclosure are disposed on the side surfaces of the electrode assembly. The battery in the present disclosure preferably includes two current collecting terminals for one electrode assembly. 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 on the electrode assembly 10. In FIG. 1(b), the pair of current collecting terminals 20 are disposed to face each other in the longitudinal direction of the electrode assembly 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 squares, rectangles, rhombuses, trapezoids, and parallelograms. The shape of the collector terminal 20 in FIG. 3(a) is rectangular. In this rectangle, the thickness direction D T The short side extends along the direction parallel to the thickness direction D T The long side extends along a direction perpendicular to the plane of the arrow.

[0028] When the battery is viewed from the side from the collector terminal side, the outer edge of the collector 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 collector terminal 20 is located inside the outer edge E1 of the electrode body 10. In other words, the outer edge E2 of the collector terminal 20 is encompassed by the outer edge E1 of the electrode body 10 over its entire periphery.

[0029] For example, in FIG. 3(a), the length (total circumference) of the outer edge E1 of the electrode body 10 is L1, and the length (total circumference) 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. Also, in FIG. 3(a), for example, 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's say. L a L for b The ratio (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 c and the thickness direction D T The length of the outer edge E2 in the direction perpendicular to L d Let's say. L c L for d The ratio (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, in FIG. 3(a), for example, the length of the gap between the outer edge E1 and the outer edge E2 is δ. δ may be greater than 0 mm, and may be 0.3 mm or more, or may be 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 assembly and seals the electrode assembly together with the current collecting terminal. As shown in FIG. 2, when the electrode assembly 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 that forms the outer edge of the current collecting terminal 20 and the surface that forms the outer edge of the electrode assembly 10. Also, as shown in FIG. 4(a), a fused portion X, where the inner surfaces of the laminate film 30 are fused together, is arranged at the corner of the current collecting terminal 20. It is preferable that the fused surface at the fused portion X does not have a gap. The laminate film may have one fused portion X, or two or more fused portions X. Furthermore, a fused portion X may be arranged at each of two corners of the current collecting terminal that are opposite in the thickness direction. Also, in FIG. 4(a), an end adhesion portion Y, where the ends of the laminate film 30 are fused together, is arranged. The end adhesion portion Y may be bent to fit the shape of the current collecting terminal. This is because excess space can be reduced. Also, as shown in Fig. 4(b), the shape of the current collecting terminal 20 may be a rectangle, and fused portions X may be disposed at all 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, first page S a and the second surface S b The surface S connecting 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. 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 collector terminal 20, the fused portion X is disposed at a corner that constitutes the outer edge E2 of the current collector terminal 20. Specifically, the corner that constitutes the outer edge E2 of the current collector terminal 20 coincides with the 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 defined as w. The width w is, for example, 0.1 mm or more, and may be 0.3 mm or more, or even 0.6 mm or more. On the other hand, 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 from above in the thickness direction, the end position of the laminate film 30 on the current collector terminal 20 side is designated as α, and the position of the laminate film 30 corresponding to the boundary between the current collector terminal 20 and the electrode assembly 10 is designated as β. The fused portion X in FIGS. 6 and 7 is continuously disposed from the end position α to position β. Furthermore, when the direction in which the current collector terminal 20 extends from the electrode assembly 30 (axial direction) is designated as D1, the fused portion X is preferably disposed along D1. Furthermore, the fused portion X may be disposed in at least a portion of the region from the end position α to position β at D1. The length of the fused portion X at D1 is, for example, 1 mm or more, or 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 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 The inclined surface Z intersects with the electrode assembly 30. 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 refers to 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 assembly 30 (axial direction) is defined as D1, and the thickness direction of the battery is defined as D2. T The direction corresponding to D1 and D3 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 direction of the inclined plane Z is the outer side (-D2 side) of the collector terminal. As shown in FIG. 9(b), when the inclined plane Z is viewed from D2, the normal direction D Z It is preferable that the normal direction D Z It is preferable that the height component (D3 component) of the inclined surface Z2 points to the inside of the battery. Although not specifically 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 conductive materials 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 binders include rubber-based binders and fluoride-based binders.

[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, and Li4Ti5O 12 The negative electrode active material may be in the form of particles or foil, for example. 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 described above. The electrolyte layer may have a separator.

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

[0042] The negative electrode current collector collects current from the negative electrode active material layer. Examples of materials for the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include foil and mesh. The negative electrode current collector may have a negative electrode tab for connection 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 surface of the electrode body. The current collecting terminal refers to a terminal having a current collecting portion at least in part. The current collecting portion is electrically connected to, for example, a tab on the electrode body. The current collecting terminal may be entirely or partially a 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 of the present disclosure has at least a structure in which a heat-sealing layer and a metal layer are laminated. The laminate film may also have a heat-sealing layer, a metal layer, and a resin layer in this order along the thickness direction. Examples of materials for the heat-sealing layer include olefin-based resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of materials for the resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the heat-sealing layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.

[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. It is particularly preferable for the battery to be used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices. The present disclosure may also provide a battery module in which a plurality of the above-described batteries are stacked in the thickness direction.

[0046] B. Battery manufacturing method The battery manufacturing method of the present disclosure is the battery manufacturing method described above, and 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, wherein in the second covering step, the fused portion is formed using a jig that can come into 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 can be obtained in which deterioration of sealing performance is suppressed. 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 assembly and the current collecting terminal. The electrode assembly and the current collecting terminal are the same as those described above in "A. Battery," and therefore, 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 2(b), in the first covering step, the surfaces constituting the outer edge of the electrode body 10 (e.g., 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 together. Also, as shown in FIG. 2(b), an end overlap portion Z where the ends of the laminate film 30 overlap is heated. This forms an end contact portion Y where the ends of the laminate film 30 are fused together. The laminate film may be previously folded to fit the shape of the electrode body.

[0050] 3(c) and 3(d), a space S is usually formed between the laminate film 30 and the current collecting terminal 20. 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. The second covering step also forms a fused portion. The laminate film used has a folded portion for forming an inclined surface.

[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 that forms 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 first covering step described above. Furthermore, an end contact portion Y is formed by the first covering step described above. Next, as shown in FIG. 10(b), jigs 41, 42, 43, and 44 are pressed against 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 example, the length (vertical length in the drawing) of jigs 42 and 44 is shorter than the length (vertical length in the drawing) of current collecting terminal 20. As a result, a gap is formed between jigs 41 and 42, and excess portions of laminate film 30 gather in the gap. As a result, fused portion X is formed, as shown in FIG. 10(c). In addition, in the present disclosure, by using a laminate film 30 having a folded portion for forming an inclined surface, the inclined surface is stably formed.

[0053] 4.Battery The battery obtained by the above-described steps is the same as 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 any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Explanation of symbols]

[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 collector terminal, an outer edge of the current collector 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; When the battery is viewed from the side of the current collecting terminal, the shape of the current collecting terminal is rectangular, a fused portion where inner surfaces of the laminate film are fused to each other is disposed at a corner of the current collecting terminal, the fused portion has a first surface, a second surface facing the first surface and positioned outward from the first surface, and a curved surface connecting the first surface and the second surface, the fused portion extends from an end position of the laminate film on the collector 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-bonded 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. The battery according to claim 1 , wherein the inclined surface has a triangular shape in a plan view.

3. The battery according to claim 1 or 2, wherein the fused portion is disposed at each of four corners of the current collector terminal.

4. When the battery is viewed from the side of the current collecting terminal, the length L of the outer edge of the electrode body １ The length L of the outer edge of the current collecting terminal ２ The ratio (L ２ / L １ 3. The battery according to claim 1, wherein the ratio of the total mass of the battery to the total mass of the electrolyte is 0.7 or more and less than 1.

5. A method for manufacturing the battery according to claim 1 or 2, 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 constituting the outer edge of the electrode body in the structure with the laminate film; a second covering step of covering a surface of the structure that forms the outer edge of the current collecting terminal with the laminate film, In the second covering step, the fused portion is formed using a jig that can come into surface contact with a surface that constitutes the outer edge of the current collecting terminal, The method for manufacturing a battery uses a laminate film having a folded portion for forming the inclined surface as the laminate film.

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