Battery, battery module, and battery manufacturing method

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 Art

[0002] A battery such as a lithium-ion secondary battery generally includes 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, for example, in an internal space surrounded by an exterior material. 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 for sealing the exterior material, and in which a first electrode terminal and a second electrode terminal are drawn out to the outside through the first cover and the second cover, respectively. Further, Patent Document 1 describes a laminate film as the exterior material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As shown in FIG. 3 described later, the dimensions of the side member may be smaller than the dimensions of the electrode body. When such a 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 performance of the battery may deteriorate.

[0005]

Means for Solving the Problems

[0006] [1]<000007<strong>0< / strong>A battery comprising an electrode body, a side member disposed on a side surface portion of the electrode body, and a laminate film covering the electrode body, wherein when the battery is viewed from the side member side in a side view, 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, and a fusion part where inner surfaces of the laminate film are fused to each other is disposed on the side member.

[0007] [2] The battery according to [1], wherein when the battery is viewed in a plan view from the thickness direction, the fusion part is continuously disposed from an end position α of the laminate film on the side member side to a position β of the laminate film corresponding to a boundary between the side member and the electrode body.

[0008] [3] The battery according to [1] or [2], wherein when the battery is viewed from the side member side in a side view, in the thickness direction of the battery, a highest position P1 of the fusion part is lower than a highest position P2 of the laminate film disposed on the electrode body.

[0009] [4] The battery according to any one of [1] to [3], wherein when the battery is viewed from the side member side in a side view, in the thickness direction of the battery, a highest position P1 of the fusion part is lower than a highest position P3 of the electrode body.

[0010] [5] The battery according to any one of [1] to [4], wherein the fusion part is disposed at a corner portion constituting 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 member side in a side view, a shape of the side member is a quadrangle.

[0012] [7] The battery according to any one of [1] to [6], wherein a plurality of the fusion parts are arranged on the side 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 the side members, and the pair of the side members are arranged to face the electrode body.

[0015]

[10] The battery according to any one of [1] to [9], wherein when the battery is viewed from the side in the side member side, the ratio (L2 / L1) of the length L2 of the outer edge of the side member to the length L1 of the outer edge of the electrode body 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 the thickness direction.

[0017]

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

[11] .

[0018]

[13] The battery module according to

[12] , wherein the battery module has a restraint jig that restrains a plurality of batteries in the thickness direction.

[0019]

[14] The battery module according to

[12] or

[13] , wherein in a pair of the side members adjacent to each other in the thickness direction, the main surface of the laminate film disposed on one of the side members and the main surface of the laminate film disposed on the other side member do not contact each other.

[0020]

[15] The manufacturing method of 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 constituting the outer edge of the electrode body in the structure with the laminate film; and a second covering step of covering a surface constituting the outer edge of the side member in the structure with the laminate film, wherein in the second covering step, a fusion part is formed using a jig capable of surface contact with the surface constituting the outer edge of the side member.

[0021]

[16] When the battery is viewed from the side member side in side view, the shape of the side member is a quadrilateral having a first side, a second side adjacent to the first side, a third side adjacent to the second side and opposite to the first side, and a fourth side adjacent to the third side and opposite to the second side. The second covering step includes a first adhesion process of pushing a first jig and a third jig into the side member from the first side side and the third side side, respectively, and adhering the laminate film to the first side and the third side, respectively; and a second adhesion process of pushing a second jig and a fourth jig into the side member from the second side side and the fourth side side, respectively, and adhering the laminate film to the second side and the fourth side, respectively, after the first adhesion process. At least one of the first jig and the third jig has an elastic member, and in the second adhesion process, the elastic member is compressed and deformed by pushing the second jig and the fourth jig, thereby forming the fusion part. The manufacturing method of the battery according to

[15] . [Effect of the Invention]

[0022] The battery in the present disclosure has an effect of suppressing a decrease in airtightness. [Brief Description of the Drawings]

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Mode for Carrying Out the Invention

[0024] Hereinafter, the battery in the present disclosure will be described in detail with reference to the drawings. Each of the drawings shown below is schematically illustrated, and the size and shape of each part are exaggerated as appropriate for easy understanding. Also, in this specification, when expressing the manner of arranging one member with respect to another member, when simply described as "above" or "below", unless otherwise specified, it includes both the case where another member is arranged directly above or directly below so as to be in contact with a certain member, and the case where another member is arranged above or below a certain member via another member.

[0025] A. Battery FIG. 1 is a schematic perspective view illustrating an electrode body and side members 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 surface portions (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. Further, in FIG. 1(b), a first side member 20A is arranged on the first side surface portion 13 of the electrode body 10, and a second side member 20B is arranged on the third side surface portion 15 of the electrode body 10. For example, the first side member 20A is a positive electrode current collecting terminal, and the second side member 20B is a negative electrode current collecting terminal.

[0026] FIG. 2 is a schematic perspective view illustrating an electrode body, side members, and a laminate film in the present disclosure. As shown in FIG. 2(a), the laminate film 30 is, for example, a single film. Also, as shown in FIGS. 2(a) and 2(b), the laminate film 30 is folded so as to cover the entire 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. On the other hand, in FIG. 2(b), at least a part of the first side member 20A and at least a part of the second side 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 line A-A of 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 member 20 side, the outer edge E2 of the side member 20 is located inside the outer edge E1 of the electrode body 10. That is, the dimensions of the side member 20 are smaller than those of the electrode body 10.

[0028] FIG. 3(c) is a schematic side view illustrating an electrode body, a side member, and a laminate film in the present disclosure, and FIG. 3(d) is a cross-sectional view taken along line A-A of FIG. 3(c). As shown in FIGS. 3(c) and 3(d), when the electrode body 10, the side member 20, and the laminate film 30 are observed from the side member 20 side, a space S is formed 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 performance of the battery may decrease. In contrast, in the battery of the present disclosure, as shown in FIG. 4, a fusion part X where the inner surfaces (the surfaces on the side member 20 side) of the laminate film 30 are fused to each other is disposed on the side member 20.

[0029] According to the present disclosure, since the fusion part is disposed on the side member, the battery has suppressed reduction in sealing performance. As shown in FIG. 3 described above, the dimensions of the side member may be smaller than those of the electrode body. By adopting such a dimensional relationship, for example, when a plurality of batteries are stacked, contact between adjacent side members can be prevented. By preventing contact between adjacent side members, breakage of the battery is less likely to occur. Further, when a 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 performance of the battery may decrease. In the present disclosure, by disposing the fusion part X where the inner surfaces of the laminate film are fused to each other on the side member, even when the dimensions of the side member are smaller than those of the electrode body, the battery has suppressed reduction in sealing performance.

[0030] 1. Configuration of the battery The battery in the present disclosure includes 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 generation element of the battery. The shape of the electrode body is not particularly limited. For example, as shown in Fig. 1(a), it has a top surface portion 11, a bottom surface portion 12 facing the top surface portion 11, and four side surface portions (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. Both the top surface portion 11 and the bottom surface portion 12 correspond to the main surfaces of the electrode body, and the normal direction of the main surface can be defined as the thickness direction. Also, 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. For example, quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram can be mentioned. The shape of the top surface portion 11 in Fig. 1(a) is a rectangle. Also, the shape of the top surface portion may be a polygon other than a quadrilateral, or a shape having a curve such as a circle. Also, 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. For example, quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram can be mentioned.

[0033] (2) Side member The side member in the present disclosure is arranged on the side surface portion of the electrode body. The battery in the present disclosure may include one side member for one electrode body, or may include two or more side members. In the latter case, for example, as shown in Fig. 1(b), a pair of side members 20 (a first side member 20A and a second side member 20B) may be arranged to face each other with respect to the electrode body 10. Also, in Fig. 1(b), the pair of side members 20 are arranged 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 members may be arranged to face each other in the short side direction of the electrode body.

[0034] The shape of the side member is not particularly limited, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The shape of the side member 20 in Fig. 3(a) is a rectangle. In this rectangle, the short side extends along the direction parallel to the thickness direction D T and the long side extends along the direction perpendicular to the thickness direction D T . Further, the shape of the side member may be a polygon other than a quadrilateral, or a shape having a curve such as a circle. Further, the side member may have a corner portion where two sides (straight sides) intersect.

[0035] When the battery is viewed from the side member side in a side view, the outer edge of the side member is located inside the outer edge of the electrode body. For example, as shown in Fig. 3(a), the outer edge E2 of the side member 20 is located inside the outer edge E1 of the electrode body 10. In other words, the outer edge E2 of the side member 20 is entirely surrounded by the outer edge E1 of the electrode body 10. Also, the dimensions of the side member 20 are smaller than the dimensions of the electrode body 10.

[0036] For example, in Fig. 3(a), let the length (total peripheral length) of the outer edge E1 of the electrode body 10 be L1, and the length (total peripheral length) of the outer edge E2 of the side member 20 be L2. The ratio of L2 to L1 (L2 / L1) is, for example, 0.7 or more and less than 1, and may be 0.8 or more and 0.95 or less. Also, for example, in Fig. 3(a), let the length of the outer edge E1 in the thickness direction D T be L a , and the length of the outer edge E2 in the thickness direction D T be L b . The ratio of L a to L b (L b / L a ) is, for example, 0.5 or more and less than 1, and may be 0.8 or more and 0.95 or less. Also, for example, in Fig. 3(a), let the length of the outer edge E1 in the direction perpendicular to the thickness direction D T be L c , and the length of the outer edge E2 in the direction perpendicular to the thickness direction D T be L d . The ratio of L c to L d (Ld / L c )(3) is, for example, 0.5 or more and less than 1, and may be 0.8 or more and 0.95 or less. Also, for example, in FIG. 3(a), let the length of the gap between the outer edge E1 and the outer edge E2 be δ. δ is greater than 0 mm, may be 0.3 mm or more, and 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 observing the electrode body 10 and the side member 20 from the side member 20 side, 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 where the inner surfaces of the laminate film 30 are fused to each other is arranged on the side member 20. It is preferable that the fusion surface in the fusion part X has no voids. Also, in FIG. 4, an end contact part Y where the ends of the laminate film 30 are fused to each other is arranged. The end contact part Y may be bent according to the shape of the side member. This is because surplus space can be reduced.

[0038] In FIG. 5, when the battery 100 is viewed from the side from the side member 20 side, the fusion part X is arranged at the corner part constituting the outer edge E2 of the side member 20. Specifically, the corner part constituting the outer edge E2 of the side member 20 coincides with the end t of the fusion surface in the fusion part X. Also, as shown in FIG. 5, let the width of the fusion surface in the fusion part X be w. The width w is, for example, 0.1 mm or more, may be 0.3 mm or more, and 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 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 member 20 side is defined 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 defined as β. The fusion-bonded portion X in FIGS. 6 and 7 is continuously arranged from the end position α to the position β. Further, when the direction in which the side member 20 extends from the electrode body 30 is defined as D1, the fusion-bonded portion X is preferably arranged along the direction D1. Further, the fusion-bonded portion X may be arranged in at least a part of the region from the end position α to the position β in the direction D1. The length of the fusion-bonded portion X in the direction D1 is, for example, 1 mm or more, may be 3 mm or more, and may be 5 mm or more.

[0040] FIG. 8(a) is a schematic side view of a part of the battery 100 viewed from the side member 20 side, and FIG. 8(b) is a cross-sectional view taken along line A-A of FIG. 8(a). As shown in FIGS. 8(a) and 8(b), in the thickness direction D of the battery 100 T the highest position of the fusion-bonded portion X is defined as P1, the highest position of the laminate film 30 arranged on the electrode body 10 is defined as P2, and the highest position of the electrode body 10 is defined as P3. The position P1 in FIGS. 8(a) and 8(b) is lower than the position P2 in the thickness direction D T In addition, the position P1 in FIGS. 8(a) and 8(b) is lower than the position P3 in the thickness direction D T but may be the same as the position P3 or higher than the position P3. Further, the position P1 may be lower than the position of the top surface portion of the electrode body 10 in the thickness direction D T

[0041] FIG. 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 A-A of FIG. 8(c). The fusion-bonded portion X in FIGS. 8(a) and 8(b) described above is arranged at the corner of the side member 20. On the other hand, as shown in FIGS. 8(c) and 8(d), the fusion-bonded portion X is one of the sides constituting the outer edge of the side member 20, and in the thickness direction D T ​It may be arranged on a side extending in a direction intersecting with [it]. Further, the fusion part X in FIGS. 8(c) and 8(d) is arranged on the long side (the long side on the top surface part side of the electrode body) constituting the outer edge of the side member 20. Even when the fusion part X is arranged at such a position, the position P1 is in the thickness direction D T Preferably, it is lower than the position P2. Also, the position P1 in FIGS. 8(c) and 8(d) is in the thickness direction D T It is higher than the position P3, but may be the same as the position P3 or lower than the position P3. Also, the position P1 is in the thickness direction D T It may be lower than the position of the top surface part of the electrode body 10.

[0042] As shown in FIG. 9(a), the end position α of the laminate film 30 on the side member 20 side may be on the electrode body 10 side from the end position γ on the side opposite to the electrode body 10 of the side member 20. 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 (the 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] FIGS. 10(a) to 10(d) are schematic side views of a part of the battery 100 viewed from the side member 20 side, respectively. As shown in FIG. 10(a), the fusion part X is arranged at the corner part constituting the outer edge of the side member 20. Two fusion parts X are shown in FIG. 10(a), but for one side member 20, one fusion part X may be arranged, or three or more fusion parts X may be arranged. Among them, it is preferable that a plurality of fusion parts X are arranged for the side member 20. This is because the surplus parts of the laminate film 30 can be absorbed dispersedly. Also, in the end adhesion part Y in FIG. 10(a), the ends of the laminate film 30 are fused by bringing their inner surfaces into contact with each other.

[0044] As shown in FIG. 10(a), the two fusion parts X may be respectively arranged at two corners on one short side that constitutes the outer edge of the side member 20. Further, as shown in FIG. 10(b), the two fusion parts X may be respectively arranged at two corners on one long side that constitutes the outer edge of the side member 20. Further, as shown in FIG. 10(c), four fusion parts X may be respectively arranged at the four corners that constitute the outer edge (quadrilateral) of the side member 20. In the end contact part Y in FIG. 10(c), the ends of the laminate film 30 are in close contact by bringing one inner surface into contact with the other outer surface. Further, as shown in FIG. 10(d), the fusion part X may be arranged at the middle part (a part that is not a corner) of the side that constitutes the outer edge of the side member 20.

[0045] 2. Battery members The battery in the present disclosure includes an electrode body, a side member, and a laminate film.

[0046] (1) Electrode body The electrode body 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 body 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 rock salt layer-structured active materials such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 and other rock salt layer-structured active materials, spinel-type active materials such as LiMn2O4, olivine-type active materials such as LiFePO4. Further, sulfur (S) may be used as the positive electrode active material. The shape of the positive electrode active material is, for example, particulate.

[0048] 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. Further, the liquid electrolyte (electrolyte 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.

[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 oxide active materials such as Li4Ti5O 12 and the like. The shape of the negative electrode active material is, for example, particulate or foil-like. 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 conducts current collection for 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 foil-like and mesh-like. The positive electrode current collector may have a positive electrode tab for connecting to a positive electrode current collection terminal.

[0052] The negative electrode current collector conducts current collection for the negative electrode active material layer. Examples of the material of 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-like and mesh-like. The negative electrode current collector may have a negative electrode tab for connecting to a negative electrode current collection terminal.

[0053] (2) Side member 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 partially. The current collecting portion is electrically connected to, for example, a tab in the electrode body. The current collecting terminal may be entirely a current collecting portion or partially a current collecting portion. Further, the side member may be an exterior member having no current collecting function. Further, examples of the material of 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. Further, 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 alloy, 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 the use of the battery include power sources for vehicles such as hybrid vehicles (HEV), plug-in hybrid vehicles (PHEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles. In particular, it is preferably used as a driving power source for a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), or an electric vehicle (BEV). Further, the battery in the present disclosure may be used as a power source for a moving body other than a vehicle (for example, a railway, a ship, an aircraft), or may be used as a power source for an electric product such as an information processing device.

[0056] B. Battery Module FIG. 12 is a schematic perspective view illustrating a battery module according to the present disclosure. The battery module 200 shown in FIG. 12 has a plurality of batteries 100 stacked in the thickness direction D T and includes the batteries described in the above “A. Battery”.

[0057] According to the present disclosure, by using the above-described battery, a battery module with suppressed reduction in sealing performance can be obtained.

[0058] The battery in the present disclosure is the same as that described in the above “A. Battery”, and thus the description thereof is omitted here. Further, the battery module in the present disclosure may have a restraining jig for restraining a plurality of batteries in the thickness direction. The type of the restraining jig is not particularly limited, and examples thereof include a jig that applies a restraining torque by bolts. 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 disposed 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 the position β of the laminate film 30 corresponding to the boundary between the side member 20 and the electrode body 10. Further, 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, in the thickness direction D TIn a pair of side members 20 (20C, 20D) that are adjacent to each other, it is preferable that the main surface 31 of the laminate film 30 disposed on one side member 20C and the main surface 31 of the laminate film 30 disposed on the other side member 20D do not contact each other. This is because damage due to contact can be prevented. Further, when a fusion part is disposed on the main surface of the laminate film, the fusion part is included in the main surface of the laminate film. That is, it is preferable that the fusion part disposed on the main surface of the laminate film does not contact the main surface of the laminate film disposed on the other side member. Further, in a state where a restraint pressure is applied to the battery by a restraint jig, the above-described position P1 may be lower than the above-described position P2 and may also be lower than the above-described position P3.

[0060] C. Method for manufacturing battery The method for manufacturing a battery according to the present disclosure is the method for manufacturing a battery described above, and includes a preparation step of preparing a structure having the above-described electrode body and the above-described side member, and 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. In the second covering step, the fusion part is formed using a jig that can be in surface contact with the surface constituting the outer edge of the side member.

[0061] According to the present disclosure, by forming the fusion part, a battery with suppressed reduction in sealing performance can be obtained.

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

[0063] 2. First covering step The first covering step in the present disclosure is a step of covering the outer edge of the electrode body in the above-described 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 (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 brought into close contact with each other. Further, as shown in FIG. 2(b), the end overlapping portion Z where the ends of the laminate film 30 overlap each other is heated. Thereby, an end contact portion Y in which the ends of the laminate film 30 are fused is formed. The laminate film may be pre-bent in accordance with the shape of the electrode body.

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

[0065] 3. Second covering step The second covering step in the present disclosure is a step of covering the surface constituting the outer edge of the side 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 each other using a jig that can be in 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), due to the first covering step described above, a space S is formed between the laminate film 30 and the side member 20. Also, due to the first covering step described above, an end contact portion Y is formed. Next, as shown in FIG. 14(b), jigs 41, 42, 43, and 44 are pushed into the laminate film 30 and the side member 20. The jigs 41 to 44 are preferably heated. Thickness direction D TIn this case, the length of the jig 42 (the length in the vertical direction of the drawing) is shorter than the length of the side member 20 (the length in the vertical direction of the drawing). Therefore, a gap is formed between the jig 41 and the jig 42, and the surplus portion of the laminate film 30 gathers in this gap. As a result, as shown in FIG. 14(c), the fusion part X is formed.

[0067] Also, when the side view shape of the side member is a quadrilateral, 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 side view shape of the side member 20 is a quadrilateral. This quadrilateral 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 member 20, and the second side s2 and the fourth side s4 correspond to the long sides constituting the outer edge of the side member 20.

[0068] Next, as shown in FIG. 15(b), the first jig 41 and the third jig 43 are respectively pushed into the side member 20 from the first side s1 side and the third side s3 side. Thereby, the laminate film 30 is adhered 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 respectively have a first elastic member 51 and a third elastic member 53. Examples of the material of the elastic member include silicone rubber and fluorine rubber.

[0069] Next, as shown in FIGS. 15(c) and (d), the second jig 42 and the fourth jig 44 are respectively pushed into the side member 20 from the second side s2 side and the fourth side s4 side. Thereby, the laminate film 30 is adhered to the second side s2 and the fourth side s4 respectively (second adhesion process). At this time, by pushing 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. As a result, as shown in FIG. 15(e), the fusion part X is formed.

[0070] The situation where the fusion part X is formed will be described with reference to FIG. 16. As shown in FIG. 16(a), in the first adhesion process, the jig 45 having the elastic member 55 is pushed 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 compressed and deformed by the 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. Following the compression deformation, the surplus portion of the laminate film 30 is folded, and the fusion part X is formed.

[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, in the first adhesion process, the unheated first jig and third jig may be pushed in, and in the second adhesion process, the heated second jig and fourth jig may be pushed in. By heating the entire outer periphery of the side member 20 only with the heat input from the jigs on the long side (the second jig and the fourth jig), the structure of the sealing machine can be simplified.

[0072] As shown in FIG. 17(a), in the state where the jig 45 having the elastic member 55 is pushed in, in the thickness direction D T it is preferable that the position P5 of the apex of the end portion of the elastic member 55 on the side member 20 side is higher than the position P6 of the apex of the end portion of the side member 20 on the elastic member 55 side. By satisfying the relationship of position P5 > position P6, the inner surfaces of the laminate film 30 are strongly compressed, and a fusion part with better sealing performance is formed. That is, in the thickness direction D T the lengths of the elastic member 55 and the jig 45 are preferably longer than the length of the side member 20 in the thickness direction D T 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 may not be disposed between the jig 45 and the side member 20. Further, as shown in FIG. 17(c), a notch 55a may be disposed at the end portion t5 of the elastic member 55 on the side member 20 side. By disposing the notch 55a, the fusion part can be formed stably.

[0073] 4. Battery Regarding the battery obtained by the above-described process, since it is the same as the content described in the above "A. Battery", the description here is omitted.

[0074] The present disclosure is not limited to the above embodiments. The above embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits the same effects is included in the technical scope of the present disclosure.

Explanation of Reference Numerals

[0075] 1... Positive electrode 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 surface portion 12... Bottom surface portion 13... First side surface portion 14... Second side surface portion 15... Third side surface portion 16... Fourth side surface portion 20... Side surface member 30... Laminate film 100... Battery 200... Battery module

Claims

1. An electrode body, A side member disposed on a side surface portion of the electrode body, A single laminate film covering the electrode body, A battery comprising: When the battery is viewed from the side in the side member side, 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, On the side member, three fusion portions where inner surfaces of the laminate film are fused to each other are disposed, When the battery is viewed from the side in the side member side, a shape of the side member is a quadrangle, Each of the three fusion portions is disposed at three of four corner portions constituting the outer edge of the side member, An end contact portion where ends of the laminate film are fused to each other is disposed at a corner portion of the four corner portions of the side member where the three fusion portions are not disposed. A battery.

2. When the battery is viewed in plan from the thickness direction, the fusion portions are continuously disposed from an end position α of the laminate film on the side member side to a position β of the laminate film corresponding to a boundary between the side member and the electrode body. The battery according to claim 1.

3. When the battery is viewed from the side member side in a side view, in the thickness direction of the battery, the highest position P of the fusion part １ is lower than the highest position P of the laminate film disposed on the electrode body. The battery according to claim 1. ２ ​

4. When the battery is viewed from the side member side in a side view, in the thickness direction of the battery, the highest position P of the fusion part １ is lower than the highest position P of the electrode body ３ The battery according to claim 1, wherein the battery is lower.

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

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

7. When the battery is viewed from the side member side in a side view, the length L of the outer edge in the electrode body １ with respect to the length L of the outer edge in the side member ２ The ratio (L ２ / L １ ) is 0.7 or more and less than 1. The battery according to claim 1

8. 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 the thickness direction. The battery according to claim 1.

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

10. The battery module has a restraining jig for restraining a plurality of batteries in the thickness direction. The battery module according to claim 9.

11. In a pair of the side members adjacent to each other in the thickness direction, a main surface of the laminate film disposed on one of the side members and a main surface of the laminate film disposed on the other side member do not contact each other. The battery module according to claim 10.

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