Battery, battery module, and method for manufacturing battery

Abstract

To provide a battery capable of suppressing deterioration of sealing performance.SOLUTION: A battery includes an electrode body, a side member located on a side surface part of the electrode body, and a laminate film covering the electrode body. An outer edge of the side member is located inside of an outer edge of the electrode body when the battery is side-viewed from the side member side. The laminate film is arranged to cover a surface composing the outer edge of the side member and a surface composing the outer edge of the electrode body when the battery is side-viewed from the side member side.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a battery, a battery module, and a method for manufacturing a battery. [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, with the first electrode terminal and the second electrode terminal being drawn out to the outside through the first cover and the second cover, respectively. Patent Document 1 also describes a laminate film as the exterior material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-108623 A Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in Fig. 3, which will be described later, the dimensions of the side surface member may be made smaller than the dimensions of the electrode body. If a side surface member having such a dimensional relationship is sealed with a laminate film, for example, wrinkles may occur in the laminate film, which may reduce the sealing performance of the battery.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and has as its main object to provide a battery in which deterioration of sealing property is suppressed. [Means for solving the problem]

[0006] [1] A battery comprising an electrode body, a side member arranged on a side portion of the electrode body, and a laminate film covering the electrode body, wherein when the battery is viewed from the side of the side member, the outer edge of the side member 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 side member and a surface constituting the outer edge of the electrode body, and a fused portion in which the inner surfaces of the laminate film are fused to each other is arranged on the side member.

[0007] [2] The battery described in [1], wherein when the battery is viewed in a plane from the thickness direction, the fused portion is continuously arranged from an end position α of the laminate film on the side member side to a position β of the laminate film corresponding to the boundary between the side member and the electrode body.

[0008] [3] When the battery is viewed from the side of the side member, the highest position P of the fusion portion in the thickness direction of the battery 1 is the highest position P of the laminate film arranged on the electrode body. 2 The battery according to [1] or [2],

[0009] [4] When the battery is viewed from the side of the side member, the highest position P of the fusion portion in the thickness direction of the battery 1 The highest position P of the electrode body 3 A battery according to any one of [1] to [3].

[0010] [5] The battery according to any one of [1] to [4], wherein the fused portion is disposed at a corner portion that constitutes the outer edge of the side member.

[0011] [6] The battery according to any one of [1] to [5], wherein when the battery is viewed from the side of the side member, the shape of the side member is rectangular.

[0012] [7] The battery according to any one of [1] to [6], wherein a plurality of the fused portions are arranged on the side surface member.

[0013] [8] The battery according to any one of [1] to [7], wherein the side member is a current collecting terminal.

[0014] [9] The battery according to any one of [1] to [8], wherein the battery includes a pair of side members, the pair of side members being arranged to face each other relative to the electrode body.

[0015]

[10] When the battery is viewed from the side of the side member, the length L of the outer edge of the electrode body 1 The length L of the outer edge of the side member 2 Percentage of (L 2 / L 1 ) is 0.7 or more and less than 1.

[0016]

[11] The battery according to any one of [1] to

[10] , wherein the electrode body 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 a thickness direction.

[0017]

[12] A battery module having a plurality of batteries stacked in a thickness direction, the batteries being the battery according to any one of [1] to

[11] .

[0018]

[13] The battery module according to

[12] , further comprising a restraining jig that restrains the plurality of batteries in the thickness direction.

[0019]

[14] The battery module according to

[12] or

[13] , wherein in a pair of side members adjacent in the thickness direction, a main surface of the laminate film arranged on one of the side members is not in contact with a main surface of the laminate film arranged on the other side member.

[0020]

[15] A method for manufacturing a battery according to any one of [1] to

[11] , comprising: a preparation step of preparing a structure having the electrode body and the side member; 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 side member 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 side member.

[0021]

[16] When the battery is viewed from the side of the side member, the shape of the side member is quadrangle, the quadrangle having a first side, a second side adjacent to the first side, a third side adjacent to the second side and facing the first side, and a fourth side adjacent to the third side and facing the second side, and the second covering step is a first adhesion treatment in which a first jig and a third jig are pressed from the first side side and the third side side of the side member, respectively, to bring the laminate film into close contact with the first side and the third side, respectively. and after the first adhesion process, a second jig and a fourth jig are pressed into the second side and the fourth side of the side member, respectively, to adhere the laminate film to the second side and the fourth side, respectively, wherein at least one of the first jig and the third jig has an elastic member, and in the second adhesion process, by pressing the second jig and the fourth jig into the side member, the elastic member is compressed and deformed to form the fused portion.

[15] The method for manufacturing a battery described in Effect of the Invention

[0022] The battery according to the present disclosure has an effect of suppressing deterioration of the sealing property. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic perspective view illustrating an electrode body and a side member according to the present disclosure. [Diagram 2] 2 is a schematic perspective view illustrating an electrode body, a side member, and a laminate film in the present disclosure. FIG. [Diagram 3] 1A and 1B are a schematic side view and a schematic cross-sectional view illustrating an electrode body, a side member, and a laminate film in 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] 1A and 1B are a schematic side view and a schematic cross-sectional view illustrating a portion of a battery according to the present disclosure. [Figure 9] FIG. 2 is a schematic cross-sectional view illustrating a portion of a battery according to the present disclosure. [Figure 10] FIG. 2 is a schematic side view illustrating a portion of a battery in the present disclosure. [Figure 11] 1 is a schematic cross-sectional view illustrating an electrode body according to the present disclosure. [Figure 12] FIG. 1 is a schematic perspective view illustrating a battery module according to the present disclosure. [Figure 13] 1 is a schematic cross-sectional view illustrating a battery module according to the present disclosure. [Figure 14] FIG. 2 is a schematic side view illustrating a second coating step in the present disclosure. [Figure 15] FIG. 2 is a schematic side view illustrating a second coating step in the present disclosure. [Figure 16] FIG. 2 is a schematic side view illustrating a second coating step in the present disclosure. [Figure 17] FIG. 2 is a schematic side view illustrating a jig in the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The battery of the present disclosure will be described in detail below 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" simply refers to 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, unless otherwise specified.

[0025] A.Battery FIG. 1 is a schematic perspective view illustrating an electrode body and a side surface member 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 side surface member 20A is disposed on the first side surface portion 13 of the electrode body 10, and a second side surface member 20B is disposed on the third side surface portion 15 of the electrode body 10. For example, the first side surface member 20A is a positive electrode current collector terminal, and the second side surface member 20B is a negative electrode current collector terminal.

[0026] 2 is a schematic perspective view illustrating an electrode body, a side surface member, 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 side surface member 20A and at least a part of the second side surface member 20B are located inside the folded laminate film 30.

[0027] Fig. 3(a) is a schematic side view illustrating an electrode body and a side member in 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 body 10 and the side member 20 are observed from the side of the side member 20, the outer edge E 2 is the outer edge E of the electrode body 10 1 That is, the dimensions of the side member 20 are smaller than the dimensions of the electrode body 10.

[0028] FIG. 3(c) is a schematic side view illustrating the electrode body, side member, and 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 FIG. 3(c) and (d), when the electrode body 10, side member 20, and laminate film 30 are observed from the side member 20 side, a space S is generated between the laminate film 30 and the side member 20. Therefore, when the side member 20 is sealed with the laminate film 30, wrinkles may occur in the laminate film 30 due to the excess portion 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 FIG. 4, a fusion portion X is arranged on the side member 20, where the inner surfaces (surfaces on the side member 20 side) of the laminate film 30 are fused to each other.

[0029] According to the present disclosure, since the fusion portion is disposed on the side member, the battery suppresses the deterioration of the sealing property. As shown in FIG. 3 described above, the size of the side member may be smaller than the size 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 side members from contacting each other. By preventing the contact of adjacent side members, the battery is less likely to be damaged. In addition, when the side member having such a dimensional relationship is 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 side member, the battery suppresses the deterioration of the sealing property even when the size of the side member is smaller than the size of the electrode body.

[0030] 1. Battery configuration The battery according to the present disclosure comprises at least an electrode body, a side member, and a laminate film.

[0031] (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.

[0032] The shape of the top surface portion 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 top surface portion 11 in FIG. 1(a) is a rectangle. The shape of the top surface portion may be a polygon other than a quadrilateral, or may be a shape having a curve such as a circle. The shape of the bottom surface portion is the same as that of the top surface portion. The shape of the side surface portion is not particularly limited, but examples thereof include quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram.

[0033] (2) Side members The side surface member in the present disclosure is disposed on the side surface of the electrode body. The battery in the present disclosure may have one side surface member for one electrode body, or may have two or more side surface members. In the latter case, for example, as shown in FIG. 1(b), a pair of side surface members 20 (a first side surface member 20A and a second side surface member 20B) may be disposed to face the electrode body 10. Also, in FIG. 1(b), the pair of side surface members 20 are disposed to face each other in the longitudinal direction of the electrode body 10. On the other hand, although not particularly shown, the pair of side surface members may be disposed to face each other in the lateral direction of the electrode body.

[0034] The shape of the side member is not particularly limited, but examples thereof include quadrilaterals such as squares, rectangles, rhombus, trapezoids, and parallelograms. The shape of the side member 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 . The shape of the side surface member may be a polygon other than a rectangle, or may be a shape having a curve such as a circle. The side surface member may have a corner where two sides (straight sides) intersect.

[0035] When the battery is viewed from the side of the side member, the outer edge of the side member is located inside the outer edge of the electrode body. 2 is the outer edge E of the electrode body 10 1 In other words, the outer edge E of the side member 20 is located on the inner side. 2 The outer edge E of the electrode body 10 is 1 The dimensions of the side member 20 are smaller than the dimensions of the electrode body 10.

[0036] For example, in FIG. 3(a), the outer edge E 1 The length (total circumference) of L 1 The outer edge E of the side member 20 2 The length (total circumference) of L 2 Let us assume that L 1 L for 2 Percentage of (L 2 / L 1 ) may be, for example, 0.7 or more and less than 1, or 0.8 or more and 0.95 or less. T Outer edge E 1 The length of L a and the thickness direction D T Outer edge E 2 The length of 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 outer edge E in the direction perpendicular to 1 The length of L c and the thickness direction D T The outer edge E in the direction perpendicular to 2 The length of 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. 1 and outer edge E 2 The length of the gap between the first and second electrodes is defined as δ. δ is 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.

[0037] (3) Laminate film The laminate film in the present disclosure covers the electrode body and seals the electrode body together with the side member. As shown in FIG. 2, when the electrode body 10 and the side member 20 are observed from the side of the side member 20, the laminate film 30 is arranged so as to cover the surface constituting the outer edge of the side member 20 and the surface constituting the outer edge of the electrode body 10. Also, as shown in FIG. 4, a fusion part X in which the inner surfaces of the laminate film 30 are fused together is arranged on the side member 20. It is preferable that the fusion surface in the fusion part X does not have a gap. Also, in FIG. 4, an end adhesion part Y in which the ends of the laminate film 30 are fused together is arranged. The end adhesion part Y may be folded to match the shape of the side member. This is because excess space can be reduced.

[0038] In FIG. 5, when the battery 100 is viewed from the side of the side member 20, the fused portion X is located at the outer edge E 2 Specifically, the side member 20 is disposed at a corner portion that constitutes the outer edge E 2The corners constituting the fusion surface coincide with the end t of the fusion surface of the fusion portion X. As shown in Fig. 5, the width of the fusion surface of the fusion 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. On the other hand, the width w is, for example, 1.2 mm or less.

[0039] 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 side of the side member 20 is designated as α, and the position of the laminate film 30 corresponding to the boundary between the side member 20 and the electrode body 10 is designated as β. The fused portion X in Figures 6 and 7 is continuously disposed from the end position α to position β. The direction in which the side member 20 extends from the electrode body 30 is designated as D. 1 In this case, the fusion part X is in the direction D 1 It is preferable that the fused portion X is arranged along the direction D. 1 The direction D may be located in at least a part of the region from the end position α to the position β. 1 The length of the fused portion X in is, for example, 1 mm or more, may be 3 mm or more, or may be 5 mm or more.

[0040] Fig. 8(a) is a schematic side view of a part of the battery 100 seen from the side of the side member 20, and Fig. 8(b) is a cross-sectional view taken along the line AA in Fig. 8(a). T The highest point of the fusion part X is P 1 The highest position of the laminate film 30 placed on the electrode body 10 is P 2 The highest position of the electrode body 10 is P 3 Position P in Fig. 8(a) and (b) 1 is the thickness direction D T At position P 2 Also, at position P in Fig. 8(a) and (b), 1 is the thickness direction D T At position P 3 Lower, but at position P 3 and the position P 3 Also, position P1 is the thickness direction D T , it may be lower than the position of the top surface of the electrode body 10.

[0041] 8(c) is a schematic side view of a part of the battery 100 viewed from the side member 20 side, and FIG. 8(d) is a cross-sectional view taken along line AA in FIG. 8(c). The fused parts X in FIG. 8(a) and (b) are disposed at corners of the side member 20. On the other hand, as shown in FIG. 8(c) and (d), the fused parts X are disposed at the corners of the sides constituting the outer edge of the side member 20 in the thickness direction D. T 8(c) and (d) is disposed on a long side (long side on the top surface side of the electrode body) that constitutes the outer edge of the side member 20. Even when the fusion part X is disposed in such a position, the position P 1 is the thickness direction D T At position P 2 It is preferable that the position P 1 is the thickness direction D T At position P 3 Higher, but at position P 3 and the position P 3 Also, position P 1 is the thickness direction D T , it may be lower than the position of the top surface of the electrode body 10.

[0042] As shown in FIG. 9(a), the end position α of the laminate film 30 on the side of the side member 20 may be closer to the electrode body 10 than the end position γ of the side member 20 opposite the electrode body 10. That is, when the battery is viewed in plan from the thickness direction, the laminate film 30 may cover a part of the side member 20. In this case, a part of the side member 20 (a part not covered by the laminate film 30) is exposed. On the other hand, as shown in FIG. 9(b), the end position α may coincide with the end position γ. That is, when the battery is viewed in plan from the thickness direction, the laminate film 30 may cover the entire side member 20.

[0043] 10(a) to (d) are schematic side views of a part of the battery 100 viewed from the side of the side member 20. As shown in FIG. 10(a), the fusion part X is disposed at a corner portion constituting the outer edge of the side member 20. Although two fusion parts X are shown in FIG. 10(a), one fusion part X may be disposed for one side member 20, or three or more fusion parts X may be disposed. Among them, it is preferable that a plurality of fusion parts X are disposed for the side member 20. This is because the surplus part of the laminate film 30 can be dispersed and absorbed. Moreover, the end contact part Y in FIG. 10(a) is fused by contacting the inner surfaces of the ends of the laminate film 30 with each other.

[0044] As shown in FIG. 10(a), the two fusion parts X may be disposed at two corners of one short side constituting the outer edge of the side member 20. As shown in FIG. 10(b), the two fusion parts X may be disposed at two corners of one long side constituting the outer edge of the side member 20. As shown in FIG. 10(c), four fusion parts X may be disposed at four corners constituting the outer edge (rectangle) of the side member 20. The end contact part Y in FIG. 10(c) is in contact with the end parts of the laminate film 30 by contacting the inner surface of one side with the outer surface of the other side. As shown in FIG. 10(d), the fusion part X may be disposed at the middle part (part other than the corner part) of the side constituting the outer edge of the side member 20.

[0045] 2. Battery components The battery according to the present disclosure comprises an electrode body, a side member, and a laminate film.

[0046] (1) Electrode body The electrode assembly in the present disclosure usually 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. For example, the electrode assembly 10 shown in Fig. 11 has a positive electrode current collector 4, a positive electrode active material layer 1, an electrolyte layer 3, a negative electrode active material layer 2, and a negative electrode current collector 5, in this order in the thickness direction.

[0047] 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 O 2 Rock salt layered active materials such as LiMn 2 O 4 Spinel-type active materials such as LiFePO 4 Examples of the positive electrode active material include olivine type active materials such as those mentioned above. Sulfur (S) may also be used as the positive electrode active material. The positive electrode active material may be in the form of particles, for example.

[0048] The conductive material may be, for example, a carbon material. 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) may be, for example, LiPF 6 and a solvent such as a carbonate-based solvent. Examples of the binder include a rubber-based binder and a fluoride-based binder.

[0049] 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 Li 4 Ti 5 O 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] (2) Side members The side member in the present disclosure is disposed on the side surface of the electrode body. The side member is not particularly limited as long as it is a member disposed on the side surface of the electrode body, but is preferably a current collecting terminal. 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 the current collecting portion in its entirety, or may be a current collecting portion in its entirety. The side member may also be an exterior member that does not have a current collecting function. Examples of materials for the side member include metals such as SUS.

[0054] (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 also 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 exterior body is, for example, 80 μm or more and 250 μm or less.

[0055] (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), and may also be used as a power source for electrical products such as information processing devices.

[0056] B. Battery module 12 is a schematic perspective view illustrating a battery module according to the present disclosure. T The battery 100 has a plurality of batteries 100 stacked in a stacked manner. The batteries 100 are the batteries described above in "A. Battery."

[0057] According to the present disclosure, by using the above-described battery, a battery module is obtained in which deterioration of the sealing property is suppressed.

[0058] The battery in the present disclosure is similar to that described in "A. Battery" above, and therefore the description here is omitted. The battery module in the present disclosure may also have a restraining jig that restrains multiple batteries in the thickness direction. The type of restraining jig is not particularly limited, but examples include a jig that applies restraining torque by a bolt. The restraining pressure applied by the restraining jig is, for example, 1 MPa or more and 50 MPa or less.

[0059] As shown in Fig. 13, the laminate film 30 arranged on the side member 20 has a main surface portion 31 and a wall portion 32. The wall portion 32 is located between the main surface portion 31 and a position β of the laminate film 30 that corresponds to the boundary between the side member 20 and the electrode body 10. When a restraining pressure is applied to the battery by the restraining jig, the battery is compressed in the thickness direction. In such a state, the thickness direction D T In a pair of side members 20 (20C, 20D) adjacent to each other in the side surface member 20, it is preferable that the main surface portion 31 of the laminate film 30 arranged on one side member 20C is not in contact with the main surface portion 31 of the laminate film 30 arranged on the other side member 20D. This is because damage due to contact can be prevented. Furthermore, when a fusion portion is arranged on the main surface portion of the laminate film, the fusion portion is included in the main surface portion of the laminate film. In other words, it is preferable that the fusion portion arranged on the main surface portion of the laminate film is not in contact with the main surface portion of the laminate film arranged on the other side member. Furthermore, when a restraining pressure is applied to the battery by the restraining jig, at the above-mentioned position P 1 is the above-mentioned position P 2 It may be lower than the above-mentioned position P 3 It may be lower.

[0060] C. Battery manufacturing method The manufacturing method of a 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 side member, a first covering step of covering the outer edge of the electrode body in the structure with the laminate film, and a second covering step of covering the outer edge of the side member in the structure with the laminate film, and in the second covering step, the fusion portion is formed using a jig that can make surface contact with the surface that constitutes the outer edge of the side member.

[0061] According to the present disclosure, by forming a fused portion, a battery in which deterioration of sealing performance is suppressed can be obtained.

[0062] 1. Preparation process The preparation step in the present disclosure is a step of preparing a structure having the electrode body and the side member. The electrode body and the side member are the same as those described in "A. Battery" above, so a description thereof will be omitted here.

[0063] 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 be adhered to each other. Also, 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 to each other is formed. The laminate film may be previously folded to match the shape of the electrode body.

[0064] In the first covering step, a space S is usually formed between the laminate film 30 and the side member 20, as shown in Fig. 3(c) and (d). This space S disappears in the second covering step described below, and a fused portion is formed instead.

[0065] 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 side surface member with the laminate film. Also, in the second covering step, a fused portion is formed.

[0066] In the second covering step, the side member and the laminate film are brought into close contact with a jig capable of surface contact with the surface constituting the outer edge of the side member. FIG. 14 is a schematic side view illustrating the second covering step in the present disclosure. As shown in FIG. 14(a), a space S is formed between the laminate film 30 and the side member 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. 14(b), jigs 41, 42, 43, and 44 are pressed into the laminate film 30 and the side member 20. It is preferable that the jigs 41 to 44 are heated. In the thickness direction D, T In this figure, the length of the jig 42 (the length in the vertical direction in the drawing) is shorter than the length of the side member 20 (the length in the vertical direction in the drawing). Therefore, a gap is generated between the jig 41 and the jig 42, and the excess portion of the laminate film 30 gathers in the gap. As a result, a fused portion X is formed as shown in FIG. 14(c).

[0067] In addition, when the shape of the side surface member 20 is a rectangle in side view, the second covering step may include a first adhesion process and a second adhesion process described later. For example, as shown in FIG. 15(a), the shape of the side surface member 20 is a rectangle in side view. This rectangle has a first side s1, a second side s2 adjacent to the first side s1, a third side s3 adjacent to the second side s2 and facing the first side s1, and a fourth side s4 adjacent to the third side s3 and facing the second side s2. In FIG. 15(a), the first side s1 and the third side s3 correspond to the short sides constituting the outer edge of the side surface member 20, and the second side s2 and the fourth side s4 correspond to the long sides constituting the outer edge of the side surface member 20.

[0068] Next, as shown in Fig. 15(b), a first jig 41 and a third jig 43 are pressed in from the first side s1 and the third side s3 of the side member 20, respectively. This causes the laminate film 30 to adhere to the first side s1 and the third side s3, respectively (first adhesion process). In Fig. 15(b), the first jig 41 and the third jig 43 have a first elastic member 51 and a third elastic member 53, respectively. Examples of materials for the elastic members include silicone rubber and fluororubber.

[0069] Next, as shown in Figures 15(c) and (d), the second jig 42 and the fourth jig 44 are pressed in from the second side s2 and the fourth side s4 of the side member 20, respectively. This causes the laminate film 30 to adhere to the second side s2 and the fourth side s4, respectively (second adhesion process). At this time, by pressing in the second jig 42 and the fourth jig 44, the first elastic member 51 and the third elastic member 53 are compressed and deformed. This forms a fused portion X, as shown in Figure 15(e).

[0070] The circumstances under which the fused portion X is formed will be described with reference to Fig. 16. As shown in Fig. 16(a), in the first adhesion process, a jig 45 having an elastic member 55 is pressed into the side member 20. While maintaining this state, as shown in Fig. 16(b), in the second adhesion process, the elastic member 55 is compressively deformed by a jig 46. At this time, since the elastic member 55 is softer than the side member 20, the jig 45, and the jig 46, it is preferentially compressed and deformed, and following this compressive deformation, the excess portion of the laminate film 30 is folded, forming the fused portion X.

[0071] In the present disclosure, it is preferable that the first side and the third side correspond to the short sides constituting the outer edge of the side member 20, and the second side and the fourth side correspond to the long sides constituting the outer edge of the side member 20. In this case, the first and third jigs, which are not heated, may be pressed in during the first adhesion process, and the second and fourth jigs, which are heated, may be pressed in during the second adhesion process. By heating the entire outer edge of the side member 20 only with heat input from the jigs on the long side (the second and fourth jigs), the structure of the sealing machine can be simplified.

[0072] As shown in FIG. 17(a), in a state where a jig 45 having an elastic member 55 is pressed, T In the figure, the position P of the apex of the end of the elastic member 55 on the side of the side member 20 5 is the apex position P of the end portion of the side member 20 on the elastic member 55 side. 6 Higher is preferable. Position P 5 >Position P 6 By satisfying the above relationship, the inner faces of the laminate film 30 are strongly compressed with each other, and a fused portion with better sealing properties is formed. T The length of the elastic member 55 and the jig 45 in the thickness direction D T It is preferable that the length of the elastic member 55 is longer than the length of the side member 20 in FIG. 17(a). In addition, in FIG. 17(a), a part of the elastic member 55 is disposed between the jig 45 and the side member 20. On the other hand, as shown in FIG. 17(b), the elastic member 55 does not have to be disposed between the jig 45 and the side member 20. In addition, as shown in FIG. 17(c), a notch 55a may be disposed at the end t5 of the elastic member 55 on the side member 20 side. By disposing the notch 55a, the fusion portion can be stably formed.

[0073] 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.

[0074] 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]

[0075] 1...Cathode active material layer 2...Negative electrode active material layer 3...Electrolyte layer 4...Positive electrode current collector 5...Negative electrode current collector 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...Side member 30...Laminating film 100...battery 200…Battery module

Claims

1. An electrode body; A side surface member disposed on a side surface portion of the electrode body; A laminate film covering the electrode body; A battery comprising: When the battery is viewed from the side of the side member, an outer edge of the side member 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 side member 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 side surface member, When the battery is viewed from the side of the side member, the side member has a rectangular shape, The fused portions are disposed at four corners that form an outer edge of the side member.

2. 2. The battery according to claim 1, wherein, when the battery is viewed in a plane from the thickness direction, the fusion portion is continuously arranged from an end position α of the laminate film on the side member side to a position β of the laminate film corresponding to the boundary between the side member and the electrode body.

3. When the battery is viewed from the side of the side member, the highest position P of the fusion portion in the thickness direction of the battery １ is the highest position P of the laminate film arranged on the electrode body. ２ The battery of claim 1 .

4. When the battery is viewed from the side of the side member, the highest position P of the fusion portion in the thickness direction of the battery １ The highest position P of the electrode body ３ The battery of claim 1 .

5. The battery of claim 1 , wherein the side member is a current collecting terminal.

6. The battery includes a pair of the side members, The battery according to claim 1 , wherein the pair of side members are disposed so as to face each other relative to the electrode body.

7. When the battery is viewed from the side of the side member, the length L of the outer edge of the electrode body １ The length L of the outer edge of the side member ２ The ratio (L ２ / L １ 2. The battery of claim 1 , wherein R is greater than or equal to 0.7 and less than 1.

8. 2. The battery according to claim 1, wherein the electrode body 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 a thickness direction.

9. A battery module having a plurality of batteries stacked in a thickness direction, A battery module, wherein the battery is a battery according to any one of claims 1 to 8.

10. The battery module according to claim 9 , further comprising a restraining jig that restrains the batteries in a thickness direction.

11. 11. The battery module according to claim 10, wherein in a pair of side members adjacent in the thickness direction, a main surface of the laminate film arranged on one of the side members is not in contact with a main surface of the laminate film arranged on the other of the side members.

12. A method for producing a battery according to any one of claims 1 to 8, comprising the steps of: a preparation step of preparing a structure having the electrode body and the side member; 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 side member in the structure with the laminate film; having A battery manufacturing method, wherein in the second covering step, the fused portion is formed using a jig capable of surface-to-surface contact with a surface that constitutes the outer edge of the side member.

13. A method for manufacturing a battery, comprising the steps of: The battery comprises: An electrode body; A side surface member disposed on a side surface portion of the electrode body; A laminate film covering the electrode body; Equipped with When the battery is viewed from the side of the side member, an outer edge of the side member 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 side member 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 side surface member, The manufacturing method includes: a preparation step of preparing a structure having the electrode body and the side member; 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 side member in the structure with the laminate film; having 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 side member, When the battery is viewed from the side of the side member, the side member has a rectangular shape, the rectangle has a first side, a second side adjacent to the first side, a third side adjacent to the second side and facing the first side, and a fourth side adjacent to the third side and facing the second side, The second covering step includes: a first adhesion process in which a first jig and a third jig are pressed into the first side and the third side of the side member, respectively, to adhere the laminate film to the first side and the third side, respectively; a second adhesion process in which a second jig and a fourth jig are pressed into the second side and the fourth side of the side member, respectively, after the first adhesion process, to adhere the laminate film to the second side and the fourth side, respectively; having At least one of the first jig and the third jig has an elastic member, and in a second adhesion process, the elastic member is compressed and deformed by pushing in the second jig and the fourth jig, thereby forming the fused portion.

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