Laminated battery and method for manufacturing laminated battery

Abstract

To provide a laminated battery in which deterioration of battery performance due to the intrusion of moisture into an electrode body is suppressed.SOLUTION: A laminated battery includes an electrode body, and a laminate film that covers and encapsulates the electrode body, the laminate film has a structure in which at least a metal layer and a fusion resin layer are laminated inside the metal layer, the laminate film includes a fusion portion where ends of the laminate film are overlapped and the fusion resin layers on the inner surface are fused together, and a metal adhesion portion in part of the fusion portion where the metal layers are in adhesion to each other over the entire longitudinal area of the fusion portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a laminated battery and a method for manufacturing a laminated battery. [Background technology]

[0002] In a laminated battery in which an electrode body is covered with a laminated film, a fused portion is formed by fusing a portion of the laminated film to enclose the electrode body.

[0003] For example, Patent Document 1 discloses a method for manufacturing a secondary battery having a folded portion at at least one end in a laminated outer casing, the method comprising the steps of: abutting a pressure plate against the base point of the fold at the end of the outer casing; and, after the abutting step, sliding the pressure plate and a pressing plate positioned opposite the pressure plate so as to sandwich the end, bending the end around the base point, and clamping the end between the pressure plate and the pressing plate to form the folded portion. The surface of the pressing plate that slides against the end has an inclined surface that bends the end and a clamping surface that clamps the end, and the inclined surface is inclined so that the cross-sectional area of ​​the pressing plate narrows in the sliding direction in a cross section perpendicular to the width direction of the pressing plate, and the inclined surface is inclined in the width direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-200973 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional laminated batteries, edges of laminate films each having at least a metal layer and a fusion resin layer are overlapped to form a fusion joint where the fusion resin layers on the inner surfaces are fused together. However, moisture can penetrate into the electrode body through the fusion resin layer at the fusion joint, which can degrade battery performance.

[0006] The present disclosure has been made in consideration of the above-described circumstances, and aims to provide a laminated battery in which deterioration of battery performance due to the intrusion of moisture into the electrode body is suppressed, and a method for manufacturing such a laminated battery. [Means for solving the problem]

[0007] <1> An electrode body; a laminate film that covers and encapsulates the electrode body, The laminate film has a structure in which at least a metal layer and a fusion resin layer are laminated on the inner side of the metal layer, The laminate film has a fused portion where the ends are overlapped and the fusion resin layers on the inner surfaces are fused together, A laminated battery, wherein a part of the fused portion has a metal adhesive portion in which the metal layers are in adhesive contact with each other over the entire area in the longitudinal direction of the fused portion. <2> The fusion portion has a bent portion bent in an angular or arc shape, and the metal contact portion is arranged in an area other than the bent portion. <1> 2. The laminated battery according to claim 1. <3> The fusion portion has a plurality of the metal contact portions. <1> or <2> 2. The laminated battery according to claim 1. <4> A method for manufacturing a laminated battery, comprising: an electrode body; and a laminate film that covers and encapsulates the electrode body, the laminate film having a structure in which at least a metal layer and a fusion resin layer are laminated inside the metal layer; and the laminate film has a fusion portion where end portions of the laminate film are overlapped and the fusion resin layers on the inner surfaces are fused together, a pressing step of pressing the fused portion by sandwiching the fused portion from both sides with a pressing member and an opposing member to form a metal adhesive portion in which the metal layers are adhesively attached to each other over the entire longitudinal direction of the fused portion, In the pressing step, at least one of the pressing member and the opposing member is heated to a temperature equal to or higher than the glass transition temperature of the fusion resin layer. <5> The shape of the tip of the pressing member that comes into contact with the fused portion is curved with a curvature radius R of 0.2 mm or more and 1.68 mm or less, The shape of the tip of the opposing member that contacts the fused portion is smooth. <4> A method for manufacturing the laminated battery according to claim 1. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a laminated battery in which deterioration of battery performance due to the intrusion of moisture into the electrode assembly is suppressed, and a method for manufacturing such a laminated battery. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a laminated battery according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating a laminated battery having a bent portion at a fused portion according to an embodiment of the present disclosure. [Figure 3] 1 is a schematic cross-sectional view illustrating one step in a method for manufacturing a laminated battery according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a schematic cross-sectional view illustrating a pressing step using a pressure roll with a curved tip and an opposing roll with a smooth tip in a manufacturing method of a laminated battery according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Laminated battery> A laminated battery according to an embodiment of the present disclosure includes an electrode assembly and a laminate film that covers and encapsulates the electrode assembly. The laminate film has a structure in which at least a metal layer and a fusion resin layer are laminated inside the metal layer, and the laminate film has a fusion portion where the edges of the laminate film are overlapped and the fusion resin layers on the inner surfaces are fused together. A part of the fusion portion has a metal adhesion portion where the metal layers are in contact with each other over the entire longitudinal direction of the fusion portion.

[0011] Hereinafter, one embodiment of a laminated battery according to the present disclosure will be described with reference to the drawings. The drawings shown below are schematic illustrations, and the size and shape of each part are appropriately exaggerated to facilitate understanding.

[0012] FIG. 1 is a schematic cross-sectional view illustrating a laminated battery according to an embodiment of the present disclosure. The laminated battery 10 shown in FIG. 1 includes an electrode assembly 2 and a laminate film 4 that covers and encapsulates the electrode assembly 2. The laminate film 4 has a structure in which at least a metal layer 42 and a fusion resin layer 44 are laminated inside the metal layer 42. The laminate film 4 may also have a structure in which a protective resin layer is further formed on the outside of the metal layer 42. The laminate film 4 has a fusion section 40 in which the ends of the laminate film 4 are overlapped and the fusion resin layers 44 on the inner surfaces are fused together. A part of the fusion section 40 includes a metal adhesion section 46 in which the metal layers 42 are in close contact with each other. In the metal adhesion section 46, the metal layers 42 are in direct contact with each other without the fusion resin layer 44 interposed therebetween. In the metal adhesion section 46, the metal layers 42 are in close contact with each other across the entire longitudinal direction of the fusion section 40 (the depth direction in FIG. 1).

[0013] In conventional laminated batteries, edges of laminate films each having at least a metal layer and a fusion resin layer are overlapped to form a fusion joint where the fusion resin layers on the inner surfaces are fused together. However, moisture can penetrate into the electrode body through the fusion resin layer in the fusion joint, which can degrade battery performance. In contrast, the laminated battery 10 according to this embodiment has a metal adhesion portion 46 in part of the fused portion 40, in which the metal layers 42 are in close contact with each other over the entire longitudinal area of ​​the fused portion 40. Therefore, the metal adhesion portion 46 prevents moisture from penetrating through the fused resin layer of the fused portion, thereby preventing a decrease in battery performance.

[0014] Number of metal contact areas The fused portion of the laminate film preferably has a plurality of (i.e., two or more) metal adhesive portions. Each of the plurality of metal adhesive portions is formed by adhering the metal layers to each other over the entire longitudinal area of ​​the fused portion. By having a plurality of metal adhesive portions, deterioration of battery performance due to the penetration of moisture into the electrode body can be further suppressed.

[0015] Location of metal contact area The laminated battery according to the embodiment of the present disclosure may have a bent portion bent into an angular or arc shape at the fused portion. By having the bent portion, the structural efficiency of the laminated battery can be improved. An example of a laminated battery having a bent portion at the fused portion is shown in Figure 2. Laminated battery 10B has bent portions 40a and 40b bent into an angular or arc shape at fused portion 40 of laminate film 4. Bent portion 40a is bent at an angle of approximately 90°, and bent portion 40b is bent at an angle of approximately 0°.

[0016] When a bent portion is formed in the fused portion, it is preferable that the metal adhesion portion is disposed in an area other than the bent portion. By disposing the metal adhesion portion in an area other than the bent portion, the bent portion can be formed into a good shape. For example, in the laminated battery 10B of the embodiment shown in Fig. 2, the metal contact portion 46 is disposed between the bent portion 40b and the tip 40c of the fused portion 40, that is, in an area other than the bent portion. When the fused portion has two bent portions as in the embodiment shown in Fig. 2, the metal contact portion is preferably disposed between the base of the fused portion (i.e., the end of the fused portion 40 on the electrode body 2 side in Fig. 2) and the first bent portion (bent portion 40a in Fig. 2), between the base side and the first bent portion (bent portion 40a in Fig. 2) and the second bent portion (bent portion 40b in Fig. 2), or between the base side and the second bent portion (bent portion 40b in Fig. 2) and the tip of the fused portion (tip 40c in Fig. 2).

[0017] However, from the viewpoint of ensuring the fusion strength of the fused portion, it is preferable to place the metal adhesion portion closer to the tip of the fused portion (tip 40c in FIG. 2). For example, if the fused portion has two bent portions, it is preferable to place the metal adhesion portion between the second bent portion from the base side (bent portion 40b in FIG. 2) and the tip of the fused portion (tip 40c in FIG. 2). On the other hand, if the fusion strength of the fusion portion can be ensured, it is preferable to position the metal contact portion closer to the base of the fusion portion (the end of the fusion portion 40 on the electrode body 2 side in FIG. 2). For example, if the fusion portion has two bends, it is preferable to position the metal contact portion between the base of the fusion portion (the end of the fusion portion 40 on the electrode body 2 side in FIG. 2) and the first bend (bend 40a in FIG. 2), or between the base side and the first bend (bend 40a in FIG. 2) and the second bend (bend 40b in FIG. 2). By positioning the metal contact portion closer to the base of the fusion portion, it is possible to further suppress the intrusion of moisture from the side of the fusion portion (the side of the fusion portion 40 on the far and near sides in FIG. 2). Alternatively, the length of the fusion portion may be shortened after positioning the metal contact portion closer to the base of the fusion portion (i.e., the trimming position on the tip side of the fusion portion may be positioned closer to the base of the fusion portion).

[0018] <Laminated battery manufacturing method> Next, a method for manufacturing a laminated battery according to an embodiment of the present disclosure will be described.

[0019] A method for manufacturing a laminated battery according to an embodiment of the present disclosure is a method for manufacturing a laminated battery having an electrode body and a laminate film that covers and encapsulates the electrode body, the laminate film having a structure in which at least a metal layer and a fusion resin layer are stacked inside the metal layer, and the laminate film has a fusion portion where the ends of the laminate film are overlapped and the fusion resin layers on the inner surfaces are fused together. The method for manufacturing a laminated battery includes a pressing step in which the fused portion is sandwiched between a pressing member and an opposing member from both sides to press the fused portion, thereby forming a metal adhesive portion in which the metal layers are adhered to each other over the entire longitudinal direction of the fused portion. In this pressing step, at least one of the pressing member and the opposing member (preferably both) is heated to a temperature equal to or higher than the glass transition temperature of the fused resin layer.

[0020] Here, one embodiment of a method for manufacturing a laminated battery according to the present disclosure will be described with reference to the drawings. Fig. 3 is a schematic cross-sectional view illustrating one step in the method for manufacturing a laminated battery according to an embodiment of the present disclosure. The laminated battery shown in Fig. 1 can be obtained by the method for manufacturing a laminated battery shown in Fig. 3.

[0021] 3 has an electrode body 2 and a laminate film 4 that covers and encapsulates the electrode body 2, and the laminate film 4 has a structure in which at least a metal layer 42 and a fusion resin layer 44 are laminated on the inside of the metal layer 42. The laminate film 4 has a fusion part 40 where the ends are overlapped and the fusion resin layers 44 on the inner surfaces are fused together. The manufacturing method of a laminated battery includes a pressing step in which the laminated battery 10 is sandwiched between a pressing roll 6 as a pressing member and an opposing roll 8 as an opposing member from both sides of the fused portion 40 (top and bottom in FIG. 3 ) to press the fused portion 40. In the pressing step shown in FIG. 3 , the fused portion 40 of the laminate film 4 of the laminated battery 10 is passed between the pressing roll 6 and the opposing roll 8, which rotate in the same direction (i.e., rotate in opposite directions), so that the fused portion 40 is pressed by the pressing roll 6 and the opposing roll 8. At least one (preferably both) of the pressing roll 6 as a pressing member and the opposing roll 8 as an opposing member is heated to a temperature equal to or higher than the glass transition temperature of the resin constituting the fused resin layer 44. This pressing process melts the resin that makes up the fused resin layer 44 of the fused portion 40, and the resin with increased fluidity is pushed aside by the pressure from the pressure roll 6 and the opposing roll 8, bringing the metal layers 42 into direct contact with each other. As a result, a metal adhesion portion in which the metal layers 42 are adhered to each other is formed over the entire area of ​​the fused portion 40 in the longitudinal direction (depth direction in FIG. 3).

[0022] The direction in which the pressing member (e.g., a pressing roll) and the opposing member (e.g., an opposing roll) are pressed against the fused portion of the laminate film may be the opposite to that shown in Figure 3, i.e., the pressing member may be pressed from below in Figure 3 and the opposing member may be pressed from above.

[0023] Pressing temperature In the pressing step, at least one of the pressing member and the opposing member (preferably both) is heated to a temperature equal to or higher than the glass transition temperature of the resin constituting the fusion resin layer. This heating temperature is preferably equal to or lower than the melting point of the materials constituting the layers other than the fusion resin layer in the laminate film (e.g., materials constituting the metal layer and protective resin layer, etc.). The heating temperature in the pressing step is preferably, for example, 120°C or higher and 220°C or lower, and more preferably 160°C or higher and 220°C or lower, from the viewpoint of instantaneously melting the resin constituting the fusion resin layer.

[0024] ·clearance The clearance between the pressing member and the opposing member during the pressing process (the shortest distance where the pressing member and the opposing member face each other) is preferably equal to or greater than the total thickness of the metal layers in the laminate film that constitutes the fused portion. When the thicknesses of the metal layers in the laminate films overlapped in the fused portion are equal, the total thickness of the metal layers is twice the thickness of the metal layers. By ensuring that the clearance is equal to or greater than the total thickness of the metal layers in the fused portion, it is possible to prevent the thickness of the metal layers from decreasing.

[0025] Furthermore, when the laminate film further has a protective resin layer on the outside of the metal layer 42, the clearance between the pressing member and the opposing member is preferably equal to or less than the total thickness of the metal layer and protective resin layer in the laminate film constituting the fused portion. When the thicknesses of the metal layer and protective resin layer in the laminate films overlapped at the fused portion are equal, the total thickness of the metal layer and protective resin layer is twice the sum of the thicknesses of the metal layer and the protective resin layer. Having a clearance equal to or less than the total thickness of the metal layer and protective resin layer in the fused portion allows for smooth pressing of the fused portion, resulting in a smooth metal adhesion portion.

[0026] Here, the thickness of the metal layer and the thickness of the protective resin layer refer to the average thickness of one metal layer and one protective resin layer at the location where the laminate film is pressed. The average thickness is determined by measuring the thickness of the metal layer or protective resin layer at five randomly selected locations from the location where the laminate film is pressed, and calculating the arithmetic mean value of the thicknesses at those five locations. The total thickness of the metal layer refers to the sum of the average thickness of the metal layer in one laminate film and the average thickness of the metal layer in the other laminate film at the location where the fused portion where the ends are overlapped is pressed. The total thickness of the metal layer and the protective resin layer refers to the sum of the average thickness of the metal layer and the protective resin layer in one laminate film and the average thickness of the metal layer and the protective resin layer in the other laminate film at the location where the fused portion is pressed.

[0027] - Shape of the tip of the pressing member and the opposing member The shape of the tip of the opposing member (e.g., opposing roll) that contacts the fused portion is preferably smooth or V-shaped. When the tip of the opposing member is smooth, the amount of deformation of the laminate film at the metal contact portion is suppressed, and as a result, the influence on the bendability when forming a bent portion at the fused portion of the laminate film can be suppressed. When the tip of the opposing member is V-shaped, the adhesion between the metal layers at the metal contact portion can be further improved. It is more preferable that the shape of the tip of the opposing member is smooth from the viewpoint of the influence on the bendability when forming a bent portion at the fused portion.

[0028] On the other hand, the shape of the tip of the pressing member (e.g., pressing roll) that comes into contact with the fused portion is preferably curved from the viewpoint of preventing tearing of the metal layer in the laminate film (and the protective resin layer if further provided). FIG. 4 shows an example of a pressing process using a pressure roll with a curved tip and an opposing roll with a smooth tip. In FIG. 4, a metal adhesive portion is formed by pressing a pressure roll 6 against an opposing roll 8 from below against a fusion portion having metal layers 42A and 42B and fusion resin 44A formed by melting and fusing fusion resin layers together, based on the information in FIG. 4. The heat and pressure from the pressure roll 6 and the opposing roll 8 melts the resin of fusion resin 44A and pushes it toward the tip and base of the fusion portion (left and right in FIG. 4). As a result, the pushed-out resin forms a raised portion 48 around the metal adhesive portion. Therefore, in a pressing member (e.g., a pressing roll) with a curved tip, it is preferable that the radius of curvature R of the tip is 1.68 mm or less. By keeping the radius of curvature R of the tip within this range, the amount of fusion resin pushed aside is not too large, and the raised portion (raised portion 48 in FIG. 4) formed around the metal adhesion portion does not become too large. As a result, the influence on bendability when forming a bend in the fusion portion of the laminate film can be suppressed.

[0029] The reason why the radius of curvature R of the tip of the pressing member having a curved tip is preferably set to 1.68 mm or less will be explained with reference to FIG. The conditions under which the influence on foldability when forming a bent portion in the fused portion of the laminate film can be suppressed are assumed to be as shown in the following formula (1): X in formula (1) represents the length X of the part recessed by pressing with the pressure roll 6 at the height of the surface of the metal layer 42A before pressing. Formula (1) X≦L1 / 2 Here, L1 represents the distance from the tip of the fused portion of the laminate film to the point where the bent portion is formed. The value of X is expressed by the following formula (2). Equation (2) X=2√(R 2 -(R-2t3) 2 ) Here, R represents the radius of curvature of the tip of the pressing member, and t3 represents the average thickness of one metal layer at the location where the laminate film is pressed. 1 / 2 " represents. The following formula (3) is derived from formulas (1) and (2). Equation (3) R≦(L1 2 ) / (64t3)-t3 Furthermore, when the general values ​​of L1=3 mm and t3=0.08 mm are applied to L1 and t3, the following formula (4) is derived. Formula (4) R≦1.68

[0030] From the above, in order to suppress the influence on the bendability when forming a bent portion in the fused portion of the laminate film, it is preferable that the radius of curvature R of the tip of a pressing member (e.g., a pressing roll) having a curved tip is 1.68 mm or less.

[0031] On the other hand, the lower limit of the radius of curvature R of the tip of a pressing member (e.g., a pressing roll) having a curved tip is preferably 0.2 mm or more, from the viewpoint of preventing tearing of the metal layer in the laminate film (and the protective resin layer if further provided). From the above, it is preferable that the radius of curvature R of the tip of the pressing member is 0.2 mm or more and 1.68 mm or less.

[0032] The length of the region where the metal layers are in close contact with each other in the metal contact portion (the length in the direction perpendicular to the longitudinal and thickness directions of the fused portion (length a in the left-right direction in Figure 4)) is preferably 50 μm or more and 300 μm or less, and more preferably 80 μm or more and 200 μm or less. When the length of the region where the metal layers are in close contact with each other is equal to or less than the upper limit, the amount of fusion resin displaced is not too large, and the influence on the bendability when forming a bend in the fusion portion of the laminate film can be suppressed.When the length of the region where the metal layers are in close contact with each other is equal to or greater than the lower limit, the penetration of moisture into the electrode body can be more effectively suppressed.

[0033] The height of the raised portion (raised portion 48 in FIG. 4) formed around the metal adhesion portion is preferably 150 μm or less, and more preferably 100 μm or less. The lower the height of the raised portion, the better. When the height of the raised portion is equal to or less than the upper limit, the influence on the foldability when forming a bent portion in the fused portion of the laminate film can be suppressed. The height of the raised portion refers to the average value of the distance (height b in FIG. 4) from the surface of the metal layer in the metal adhesion portion and in the portion where the raised portion is not formed (the surface of metal layer 42A in FIG. 4) to the apex of the raised portion. The average height of the raised portion is determined by selecting five locations where the raised portion is formed, measuring the height of the raised portion, and calculating the arithmetic mean value of the heights at the five locations.

[0034] (Battery components) Next, the electrode body and laminate film that constitute the laminate battery according to this embodiment will be described.

[0035] (1) Laminate film The laminate film has at least a metal layer and a protective resin layer on the outside of the metal layer. The laminate film may be a three-layer film further having a fusion resin layer on the inside of the metal layer.

[0036] Examples of materials for the fusion resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of materials for the protective resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the fusion resin 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 protective resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the entire laminate film is, for example, 70 μm or more and 220 μm or less.

[0037] (2) Electrode body The electrode assembly functions as a power generating element of the battery. The electrode assembly typically has a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector, in this order in the thickness direction.

[0038] 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. The positive electrode active material is, for example, in the form of particles. Examples of the positive electrode active material include oxide active materials. Sulfur (S) may also be used as the positive electrode active material.

[0039] The positive electrode active material preferably contains a lithium composite oxide. The lithium composite oxide may contain at least one element selected from the group consisting of F, Cl, N, S, Br, and I. The lithium composite oxide may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc (also referred to as P63mc or P6 / mmc). The lithium composite oxide may have an O2-type structure in which the transition metal, oxygen, and lithium are primarily arranged.

[0040] Examples of lithium composite oxides having a crystal structure belonging to R-3m include Li x Me y O α X β (Me represents at least one selected from the group consisting of Mn, Co, Ni, Fe, Al, Cu, V, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, W, B, Si, and P, and X represents at least one selected from the group consisting of F, Cl, N, S, Br, and I, and the relationships 0.5≦x≦1.5, 0.5≦y≦1.0, 1≦α<2, and 0<β≦1 are satisfied.)

[0041] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 2(1.5≦x1≦2.3, M 1 contains at least one selected from the group consisting of Ni, Co, Mn, Cu and Fe, and A 1 contains at least oxygen, and A 1 The ratio of oxygen in the oxide is 85 atomic % or more. x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0≦x2≦0.5, 0≦y≦0.3, and at least one of x2 and y is not 0, M 1A represents at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, and M 1B represents at least one selected from the group consisting of Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta and W, and A2 represents at least one selected from the group consisting of F, Cl, Br, S and P.

[0042] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include M1 x M2y O2 (where M1 represents an alkali metal (preferably at least one of Na and K), M2 represents a transition metal (preferably at least one selected from the group consisting of Mn, Ni, Co, and Fe), and x + y satisfies 0 < x + y ≤ 2). Examples include composite oxides represented by this formula.

[0043] As the lithium composite oxide having an O2-type structure, for example, Li x [Li α (Mn a Co b M c ) 1-α O2 (where 0.5 < x < 1.1, 0.1 < α < 0.33, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi). Examples of such composite oxides include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2, etc.

[0044] In addition, the positive electrode preferably contains a solid electrolyte selected from the group of solid electrolytes consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes in addition to the positive electrode active material. A mode in which at least a part of the surface of the positive electrode active material is coated with a sulfide solid electrolyte, an oxide solid electrolyte, or a halide solid electrolyte is more preferable. As the halide solid electrolyte for coating at least a part of the surface of the positive electrode active material, Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≤ 1.5) [LTAF electrolyte] is preferable.

[0045] Examples of conductive materials include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. The liquid electrolyte (electrolytic solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. Examples of binders include rubber-based binders and fluoride-based binders.

[0046] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and Li4Ti5O 12 The negative electrode current collector may be in the form of, for example, a foil or a mesh. The conductive material, electrolyte, and binder are the same as those described above.

[0047] 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 layer is preferably a solid electrolyte layer. The electrolyte layer may have a separator.

[0048] The solid electrolyte preferably contains at least one solid electrolyte species selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes.

[0049] The positive electrode current collector collects current from the positive electrode active material layer. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, iron, titanium, and carbon, and aluminum alloy foil or aluminum foil is preferred. Aluminum alloy foil and aluminum foil may be manufactured using powder. The positive electrode current collector may have a foil or mesh shape, for example.

[0050] The negative electrode current collector collects 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 foil and mesh.

[0051] ·battery The laminated battery in the present disclosure is typically a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferred that the battery be used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0052] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Explanation of symbols]

[0053] 2 electrode body, 4 laminate film, 6 pressure roll, 8 opposing roll, 10, 10B laminated battery, 40 fused portion, 40a, 40b bent portion, 40c tip, 42, 42A, 42B metal layer, 44 fused resin layer, 44A fused resin, 46 metal contact portion, 48 raised portion

Claims

1. An electrode body; a laminate film that covers and encapsulates the electrode body, The laminate film has a structure in which at least a metal layer and a fusion resin layer are laminated on the inner side of the metal layer, The laminate film has a fused portion where the ends are overlapped and the fusion resin layers on the inner surfaces are fused together, a metal adhesion portion in which the metal layers are in close contact with each other over the entire longitudinal direction of the fusion portion is provided in a part of the fusion portion, A laminated battery in which the fused portion has a first bent portion and a second bent portion from the end portion on the electrode body side that is bent into an angular or arc shape, and the metal adhesion portion is arranged between the second bent portion and the tip of the fused portion.

2. The laminated battery according to claim 1 , wherein the fused portion has a plurality of the metal contact portions.

3. A method for manufacturing a laminated battery, comprising: an electrode body; and a laminate film that covers and encapsulates the electrode body, the laminate film having a structure in which at least a metal layer and a fusion resin layer are laminated inside the metal layer; and the laminate film has a fusion portion where end portions of the laminate film are overlapped and the fusion resin layers on the inner surfaces are fused together, a pressing step of pressing the fused portion by sandwiching the fused portion from both sides with a pressing member and an opposing member to form a metal adhesive portion in which the metal layers are adhesively attached to each other over the entire longitudinal direction of the fused portion, In the pressing step, at least one of the pressing member and the opposing member is heated to a temperature equal to or higher than the glass transition temperature of the fusion resin layer, A method for manufacturing a laminated battery, in which a first bent portion and a second bent portion are formed in the fused portion from the end portion on the electrode body side that is bent into an angular or arc shape, and the metal adhesion portion is positioned between the second bent portion and the tip of the fused portion.

4. The shape of the tip of the pressing member that comes into contact with the fused portion is curved with a curvature radius R of 0.2 mm or more and 1.68 mm or less, The method for manufacturing a laminated battery according to claim 3 , wherein the tip of the opposing member that contacts the fused portion has a smooth shape.

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