Laminated battery and method for manufacturing laminated battery

Abstract

The laminated battery includes an electrode body and a laminated film covering and sealing the electrode body. The laminated film has a structure in which at least a metal layer and a welded resin layer on the inside of the metal layer are laminated. The laminated film has a welded portion in which end portions overlap each other and the welded resin layers on the inner surfaces are welded to each other, and has a metal adhesion portion in which the metal layers are adhered to each other over the entire region in the longitudinal direction of the welded portion in a portion of the welded portion.

Description

Technical Field

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

[0002] In a laminated battery in which an electrode body is covered with a laminate film, a portion of the laminate film is welded to form a welded portion in order to seal the electrode body.

[0003] For example, Japanese Patent Application Laid-Open No. 2019-200973 discloses a method for manufacturing a secondary battery having a bent portion at at least one end in an outer body subjected to lamination processing. The manufacturing method comprises a process of making a pressing plate abut against the base point of the bend at the end of the outer body, and a process of forming the bent portion. After the abutment process, the pressing plate and a pressing plate arranged at a position opposite to the pressing plate are slid in a manner of clamping the end, the end is bent around the base point, and the end is clamped by the pressing plate and the pressing plate to form a bent portion. The surface of the pressing plate that slides with the end has an inclined surface for bending the end and a clamping surface for clamping the end. The inclined surface is inclined in a cross section orthogonal to the width direction of the pressing plate in such a way that the cross-sectional area of ​​the pressing plate narrows in the sliding direction. The inclined surface is inclined in the width direction. Summary of the invention

[0004] In conventional laminated batteries, the ends of laminated films having at least a metal layer and a welding resin layer overlap and the welding resin layers on the inner surfaces are welded to each other. However, water may penetrate into the electrode body through the welding resin layer at the welding portion, resulting in a decrease in battery performance.

[0005] The present disclosure has been made in view of the above-mentioned actual situation, and an object of the present disclosure is to provide a laminated battery and a method for manufacturing the laminated battery in which a reduction in battery performance due to the intrusion of water into an electrode body is suppressed.

[0006] <1> A laminated battery having: an electrode body; and a laminate film covering and sealing the electrode body, The laminate film has a structure in which at least a metal layer and a fusion resin layer inside the metal layer are stacked. The laminate film has a fusion portion where the ends overlap each other and the fusion resin layers on the inner surfaces are fusion-bonded to each other. A part of the weld portion has a metal close contact portion where the metal layers are in close contact with each other over the entire region in the longitudinal direction of the weld portion. <2> according to <1> The laminated battery described herein, wherein The welded portion has a bent portion that is bent in an angular or arc shape, and the metal close contact portion is arranged in a region other than the bent portion. <3> according to <1> or <2> The laminated battery described herein, wherein The welded portion has a plurality of the metal close contact portions. <4> A method for manufacturing a laminated battery, the laminated battery comprising an electrode body and a laminated film covering and sealing the electrode body, the laminated film having a structure in which at least a metal layer and a welding resin layer inside the metal layer are stacked, the laminated film having a welding portion in which the ends overlap each other and the welding resin layers inside are welded to each other, wherein: The manufacturing method includes a stamping step, that is, the weld portion is clamped from both sides by a pressing member and an opposing member and the weld portion is stamped to form a metal-contacting portion in which the metal layers are in close contact with each other over the entire area in the longitudinal direction of the weld 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 a glass transition temperature of the fusion resin layer. <5> according to <4> The method for producing a laminated battery described herein, wherein: The front end of the pressing member in contact with the welded portion is curved with a curvature radius R of 0.2 mm or more and 1.68 mm or less. The front end of the opposing member in contact with the welded portion has a smooth shape.

[0007] According to the present disclosure, it is possible to provide a laminated battery and a method for manufacturing the laminated battery in which a decrease in battery performance due to the intrusion of water into an electrode body is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements. Figure 1 is a schematic cross-sectional view illustrating a laminated battery according to an embodiment of the present disclosure; Figure 2 is a schematic cross-sectional view illustrating a laminated battery having a bent portion at a welded portion according to an embodiment of the present disclosure; Figure 3 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 It is a schematic cross-sectional view illustrating a press step using a pressing roller having a curved tip and a counter roller having a smooth tip in a method for manufacturing a laminated battery according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0009] <Laminated battery> The laminated battery according to the embodiment of the present disclosure includes an electrode body and a laminate film that covers and seals the electrode body. The laminate film has a structure in which at least a metal layer and a welding resin layer inside the metal layer are stacked, and the laminate film has a welding portion in which the ends overlap each other and the welding resin layers inside are welded to each other. In addition, a part of the welding portion has a metal close contact portion in which the metal layers are in close contact with each other over the entire area in the longitudinal direction of the welding portion.

[0010] Hereinafter, one embodiment of the laminated battery according to the present disclosure will be described with reference to the drawings. Each of the drawings shown below is schematically shown, and the size and shape of each part are appropriately exaggerated for easy understanding.

[0011] Figure 1 It is a schematic cross-sectional view illustrating a laminated battery according to an embodiment of the present disclosure. Figure 1 The laminated battery 10 shown has an electrode body 2 and a laminate film 4 that covers and seals the electrode body 2. The laminate film 4 has a structure in which at least a metal layer 42 and a welding resin layer 44 on the inner side of the metal layer 42 are stacked. In addition, the laminate film 4 may also have a structure that further includes a protective resin layer on the outer side of the metal layer 42. The laminate film 4 has a welding portion 40 in which the ends overlap each other and the welding resin layers 44 on the inner surfaces are welded to each other. In addition, a part of the welding portion 40 has a metal-fitting portion 46 in which the metal layers 42 are tightly attached to each other. In the metal-fitting portion 46, the metal layers 42 are in direct contact and tightly attached to each other without passing through the welding resin layer 44. In addition, in the metal-fitting portion 46, the metal layers 42 are tightly attached to each other in the length direction ( Figure 1 The entire area (in the depth direction) is closely attached.

[0012] In conventional laminated batteries, the ends of a laminated film having at least a metal layer and a welding resin layer overlap each other and the welding resin layers on the inner surface are welded to each other. However, there are cases where moisture penetrates the electrode body through the welding resin layer at the welding portion, resulting in a decrease in battery performance. In contrast, the laminated battery 10 according to the present embodiment has a metal close contact portion 46 in which the metal layers 42 are in close contact with each other over the entire region in the longitudinal direction of the weld 40 at a part of the weld 40. Therefore, the metal close contact portion 46 suppresses the intrusion of moisture through the weld resin layer of the weld, and as a result, it is possible to suppress the reduction in battery performance. Number of metal contact parts

[0013] The welded portion of the laminate film preferably has a plurality of (i.e., more than two) metal close-fitting portions. In the plurality of metal close-fitting portions, the metal layers are close-fitting to each other over the entire area in the length direction of the welded portion. By having a plurality of metal close-fitting portions, the reduction in battery performance caused by the intrusion of water into the electrode body can be further suppressed. ·Position of metal contact part

[0014] The laminated battery according to the embodiment of the present disclosure may have a bent portion that is curved in an angular or arc shape at the welded portion. The bent portion can improve the structural efficiency of the laminated battery. Here, an example of a laminated battery having a bent portion at a welded portion is shown. Figure 2 The laminated battery 10B has angled or arcuate bent portions 40a and 40b at the welded portion 40 of the laminate film 4. The bent portion 40a is bent at an angle of approximately 90°, and the bent portion 40b is bent at an angle of approximately 0°.

[0015] Furthermore, when the welded portion is formed with a bent portion, the metal close contact portion is preferably arranged in a region other than the bent portion. By arranging the metal close contact portion in a region other than the bent portion, the bent portion can be formed into a good shape. For example, in Figure 2 In the laminated battery 10B of the embodiment shown in FIG. 1 , the metal close contact portion 46 is arranged between the bent portion 40b and the front end 40c of the welded portion 40, and is arranged in the region other than the bent portion. Figure 2 In the case where the weld has two bends as shown in the embodiment shown in FIG. 1 , the metal contact portion is preferably arranged at (i) the root of the weld (i.e. Figure 2 The end of the electrode body 2 side of the middle weld 40) to the initial bending portion ( Figure 2 (ii) the first bend from the root side ( Figure 2 middle bend 40a) to the second bend ( Figure 2 (iii) between the middle bend 40b) or (iii) the second bend from the root side ( Figure 2 from the middle bending portion 40b) to the front end of the welded portion ( Figure 2 Between the middle and front ends 40c).

[0016] However, from the perspective of ensuring the welding strength of the welded portion, it is preferred to arrange the metal close contact portion closer to the front end ( Figure 2 For example, if there are two bends in the welded portion, it is preferred that the metal contact portion be arranged at the second bend from the root side ( Figure 2 from the middle bending portion 40b) to the front end of the welded portion ( Figure 2 Between the middle and front ends 40c). On the other hand, as long as the welding strength of the welded portion can be ensured, it is preferred to arrange the metal close contact portion closer to the root of the welded portion ( Figure 2For example, if the weld has two bends, the metal contact portion is preferably arranged at (i) the end of the weld 40 on the electrode body 2 side. Figure 2 The end of the electrode body 2 side of the middle weld 40) to the initial bending portion ( Figure 2 (a) between the middle bends 40a, or (ii) the first bend from the root side ( Figure 2 middle bend 40a) to the second bend ( Figure 2 By arranging the metal close contact part closer to the root of the weld part, it is possible to further suppress the moisture from entering the side of the weld part ( Figure 2 In addition, the length of the weld portion may be shortened (that is, the trimming position of the front end side of the weld portion is made closer to the root side of the weld portion) by arranging the metal close contact portion at a position closer to the root side of the weld portion. Method for manufacturing laminated battery

[0017] Next, a method for manufacturing a laminated battery according to an embodiment of the present disclosure will be described.

[0018] The laminated battery according to the embodiment of the present disclosure comprises an electrode body and a laminate film covering and sealing the electrode body. The laminate film has a structure in which at least a metal layer and a welding resin layer inside the metal layer are stacked. The laminate film has a welding portion in which the ends overlap each other and the welding resin layers inside are welded to each other. Furthermore, the manufacturing method of the laminated battery includes a stamping step, that is, the welded portion is clamped from both sides by a pressing member and an opposing member and the welded portion is stamped to form a metal-contacting portion in which the metal layers are in close contact with each other over the entire area in the longitudinal direction of the welded portion. In the stamping step, at least one of the pressing member and the opposing member (preferably both) is heated to a temperature higher than the glass transition temperature of the welded resin layer.

[0019] Here, one embodiment of a method for manufacturing a laminated battery according to the present disclosure will be described with reference to the drawings. Figure 3 2 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. Figure 3 The manufacturing method of the laminated battery shown in the figure can obtain Figure 1 The laminated battery shown.

[0020] Figure 3The laminated battery 10 shown has an electrode body 2 and a laminate film 4 that covers and seals the electrode body 2. The laminate film 4 has a structure in which at least a metal layer 42 and a welding resin layer 44 inside the metal layer 42 are stacked. The laminate film 4 has a welded portion 40 in which the ends overlap each other and the welding resin layers 44 on the inner surfaces are welded to each other. The method for manufacturing a laminated battery includes a pressing step, that is, for the laminated battery 10, a pressing roller 6 as a pressing member and an opposing roller 8 as an opposing member are used to press the laminated battery 10 from both sides ( Figure 3 The welded portion 40 is clamped and pressed. Figure 3 In the stamping process shown, the weld 40 in the laminate film 4 of the laminated battery 10 is passed between a pressing roller 6 and a relative roller 8 that rotate in the same direction (that is, in opposite directions), thereby stamping the weld 40 using the pressing roller 6 and the relative roller 8. At least one (preferably both) of the pressing roller 6 as a pressing member and the relative roller 8 as a relative member is heated to a temperature above the glass transition temperature of the resin constituting the weld resin layer 44. Through this stamping process, the resin of the weld resin layer 44 constituting the weld 40 is melted, and the resin with increased fluidity is pushed away by the pressure from the pressing roller 6 and the relative roller 8, so that the metal layers 42 are in direct contact with each other. As a result, the metal-adhering portions of the metal layers 42 that are in close contact with each other are arranged in the length direction ( Figure 3 It is formed over the entire area (in the depth direction).

[0021] In addition, the direction in which the pressing member (for example, a pressing roller) and the opposing member (for example, an opposing roller) are pressed toward the welded portion of the laminated film may be the same as that of the pressing member (for example, a pressing roller). Figure 3 In the opposite direction, that is, from Figure 3 The pressing member is pressed from the lower side and the opposing member is pressed from the upper side. Stamping temperature

[0022] At least one (preferably both) of the pressing member and the opposing member in the stamping process is heated to a temperature higher than the glass transition temperature of the resin constituting the welding resin layer. In addition, the heating temperature is preferably lower than the melting point of the material constituting the layer other than the welding resin layer in the laminated film (for example, the material constituting the metal layer and the protective resin layer). The heating temperature in the stamping process is preferably, for example, 120°C to 220°C, and from the perspective of instantaneously melting the resin constituting the welding resin layer, it is preferably 160°C to 220°C. ·gap

[0023] The gap between the pressing member and the opposing member in the punching process (the shortest distance at the position where the pressing member and the opposing member are opposite) is preferably greater than the total thickness of the metal layer in the laminated film constituting the weld. In addition, when the thickness of the metal layers of the laminated films overlapped at the weld are equal, the total thickness of the metal layers is twice the thickness of the metal layers. By making the gap greater than the total thickness of the metal layers at the weld, the reduction in the thickness of the metal layers can be suppressed.

[0024] In addition, in the case where the laminate film has a structure that further includes a protective resin layer on the outside of the metal layer 42, the gap between the pressing member and the opposing member is preferably less than the total thickness of the metal layer and the protective resin layer in the laminate film constituting the welded portion. In addition, in the case where the thickness of the metal layer and the protective resin layer of the laminate films overlapped at the welded portion are equal, the total thickness of the metal layer and the protective resin layer is twice the sum of the thickness of the metal layer and the thickness of the protective resin layer. By making the gap less than the total thickness of the metal layer and the protective resin layer at the welded portion, the welded portion can be punched well. As a result, the metal close contact portion can be formed well.

[0025] Here, the thickness of the metal layer and the thickness of the protective resin layer represent the average thickness of one metal layer and the average thickness of one protective resin layer at the punched portion of the laminated film. Regarding the average thickness, 5 locations are randomly selected from the punched portion of the laminated film to measure the thickness of the metal layer or the protective resin layer, and the thickness is set as the arithmetic mean of the thicknesses at the 5 locations. In addition, the total thickness of the metal layer represents the sum of the average thickness of the metal layer in the laminated film on one side and the average thickness of the metal layer in the laminated film on the other side at the punched portion of the welded portion where the ends overlap each other. The total thickness of the metal layer and the protective resin layer represents the sum of the average thickness of the metal layer and the average thickness of the protective resin layer in the laminated film on one side and the average thickness of the metal layer and the protective resin layer in the laminated film on the other side at the punched portion of the welded portion. ·The shape of the front end of the pressing member and the opposing member

[0026] The shape of the front end of the relative member (e.g., relative roller) in contact with the weld is preferably smooth or V-shaped. By making the front end of the relative member smooth, the deformation of the laminated film at the metal-contacting portion is suppressed. As a result, the influence on the bending property when the weld of the laminated film forms a curved portion can be suppressed. By making the front end of the relative member V-shaped, the close contact between the metal layers at the metal-contacting portion can be further improved. From the perspective of the influence on the bending property when the weld forms a curved portion, the shape of the front end of the relative member is more preferably smooth.

[0027] On the other hand, from the perspective of suppressing cracking of the metal layer (or the protective resin layer if there is also a protective resin layer) in the laminate film, the tip of the pressing member (eg, pressing roller) in contact with the welded portion is preferably curved. Here, a diagram illustrating a press process using a pressing roller having a curved tip and a counter roller having a smooth tip is shown in FIG. Figure 4 .exist Figure 4 In the process, by pressing the roller 6 from Figure 4 The metal contact portion is formed by pressing the metal layers 42A and 42B and the welding resin layer 44A, which are melted and welded, against the counter roller 8 from the bottom. In addition, the resin of the welding resin 44A is melted by the heating and pressure from the pressing roller 6 and the counter roller 8, and is pushed toward the front end side and the root side ( Figure 4 Thus, the pushed resin forms a raised portion 48 around the metal close contact portion. Therefore, in a pressing member (such as a pressing roller) having a curved front end, the curvature radius R of the front end is preferably 1.68 mm or less. By setting the curvature radius R of the front end within this range, the amount of the welding resin pushed away will not be excessive, and the ridge ( Figure 4 As a result, the influence on the bending property when the fusion bonded portion of the laminated film forms a curved portion can be suppressed.

[0028] In addition, use Figure 4 , explaining why it is preferred that the radius of curvature R of the front end of the pressing member having a curved front end be 1.68 mm or less. It is assumed that the conditions that can suppress the influence on the bendability when the welded portion of the laminated film forms a curved portion are as shown in the following formula (1). In addition, X in formula (1) represents the length X at the height of the surface of the metal layer 42A before stamping at the location that is recessed due to the stamping of the pressing roller 6. Formula (1) X≤L1 / 2 Here, L1 represents the distance from the front end of the welded portion of the laminate film to the location where the bent portion is formed. The value of X is represented by the following formula (2). Formula (2) X=2√(R 2 -(R-2t3) 2 ) Here, R represents the radius of curvature of the front end of the pressing member, and t3 represents the average thickness of a metal layer at the punched portion of the laminate film. 1 / 2 ”. The following equation (3) is derived from equation (1) and equation (2). Formula (3) R≤(L12 ) / (64t3)-t3 Furthermore, when L1=3 mm and t3=0.08 mm are substituted into L1 and t3, the following formula (4) is derived. Formula (4) R≤1.68

[0029] From the above, from the viewpoint of suppressing the influence on the bendability when a curved portion is formed at the welded portion of the laminate film, the curvature radius R of the tip of the curved pressing member (eg, pressing roller) is preferably 1.68 mm or less.

[0030] On the other hand, from the perspective of suppressing the rupture of the metal layer in the laminated film (or the protective resin layer if there is also a protective resin layer), the lower limit of the curvature radius R of the front end of the pressing member (such as a pressing roller) with a curved front end is preferably greater than 0.2 mm. Based on the above, the curvature radius R of the front end of the pressing member is preferably greater than or equal to 0.2 mm and less than or equal to 1.68 mm.

[0031] In addition, the length of the region where the metal layers are in close contact with each other at the metal close contact portion (the length in the direction perpendicular to the length direction and the thickness direction of the weld portion ( Figure 4 The length a) in the left-right direction is preferably 50 μm or more and 300 μm or less, and more preferably 80 μm or more and 200 μm or less. By making the length of the region where the metal layers are in close contact with each other less than the above upper limit, the amount of the welding resin pushed away will not be too much. Therefore, the influence on the bending property when the welding portion of the laminated film forms a curved portion can be suppressed. By making the length of the region where the metal layers are in close contact with each other more than the above lower limit, the intrusion of moisture into the electrode body can be more effectively suppressed.

[0032] The raised portion ( Figure 4 The height of the raised portion 48 in the embodiment is preferably 150 μm or less, and more preferably 100 μm or less. The lower the height of the raised portion, the better. By setting the height of the raised portion to be equal to or less than the above upper limit, it is possible to suppress the influence on the bendability when the bent portion is formed at the welded portion of the laminate film. The height of the raised portion indicates the height of the surface of the metal layer at a location where the metal close contact portion and the raised portion are not formed ( Figure 4 The distance from the surface of the metal layer 42A in the middle to the top of the protrusion ( Figure 4 The average value of the height of the protrusion b). As for the average value of the height of the protrusion, five locations where the protrusion is formed are selected, the height of the protrusion is measured, and the height is set as the arithmetic mean of the heights at the five locations.

[0033] (Battery components) Next, the electrode body and the laminate film constituting the laminated battery according to the present embodiment will be described. (1) Laminated film

[0034] The laminate film has at least a metal layer and a protective resin layer outside the metal layer. The laminate film may also be a three-layer structure film further having a fusion resin layer inside the metal layer.

[0035] As the material of the welding resin layer, for example, olefin resins such as polypropylene (PP) and polyethylene (PE) can be cited. As the material of the metal layer, for example, aluminum, aluminum alloy, and stainless steel can be cited. As the material of the protective resin layer, for example, polyethylene terephthalate (PET) and nylon can be cited. The thickness of the welding resin layer is, for example, greater than 40 μm and less than 100 μm. The thickness of the metal layer is, for example, greater than 30 μm and less than 60 μm. The thickness of the protective resin layer is, for example, greater than 20 μm and less than 60 μm. The thickness of the entire laminated film is, for example, greater than 70 μm and less than 220 μm. (2) Electrode body

[0036] The electrode body functions as a power generation element of the battery and generally has a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector in this order in the thickness direction.

[0037] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may also contain at least one of a conductive material, an electrolyte, and a binder. The shape of the positive electrode active material is, for example, a particle. Examples of the positive electrode active material include oxide active materials. In addition, sulfur (S) may also be used as the positive electrode active material.

[0038] As the positive electrode active material, preferably a lithium composite oxide is included. The lithium composite oxide may also contain at least one selected from F, Cl, N, S, Br and I. In addition, the lithium composite oxide may also have a crystal structure belonging to at least one space group selected from space groups R-3m, Immm and P63-mmc (also referred to as P63mc, P6 / mmc). In addition, the lithium composite oxide may also be a transition metal, oxygen and lithium mainly arranged in an O2 type structure.

[0039] Examples of lithium composite oxides having a crystal structure belonging to R-3m include Li x Me y O α X βMe represents at least one selected from 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. X represents at least one selected from F, Cl, N, S, Br and I. 0.5≤x≤1.5, 0.5≤y≤1.0, 1≤α<2, 0<β≤1 are satisfied.

[0040] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 A composite oxide represented by 2. Satisfying 1.5≤x1≤2.3. M 1 Contains at least one selected from Ni, Co, Mn, Cu and Fe. 1 At least oxygen. 1 The proportion of the total amount of the lithium ions is 85 atomic % or more. As a specific example, Li2NiO2 can be cited. In addition, as a lithium composite oxide having a crystal structure belonging to Immm, for example, Li x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y A composite oxide represented by 0≤x2≤0.5, 0≤y≤0.3. At least one of x2 and y is not 0. M 1A M represents at least one selected from Ni, Co, Mn, Cu and Fe. 1B represents at least one selected from Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta and W. A2 represents at least one selected from F, Cl, Br, S and P.

[0041] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include: x M2 y O2 represents a composite oxide. M1 represents an alkali metal (preferably at least one of Na and K). M2 represents a transition metal (preferably at least one selected from Mn, Ni, Co and Fe). x+y satisfies 0 <x+y≤2。

[0042] Examples of lithium composite oxides having an O2 type structure include Li x [Li α (Mn a Co b M c ) 1-αComposite oxides represented by O2. 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. M represents at least one selected from Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi. As a specific example, Li can be cited. 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 etc.

[0043] In addition, preferably, in addition to the positive electrode active material, the positive electrode further contains a solid electrolyte selected from the group of solid electrolytes consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. More preferably, 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. As the halide solid electrolyte 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].

[0044] As the conductive material, for example, carbon materials can be cited. The electrolyte can be either a solid electrolyte or a liquid electrolyte. The solid electrolyte can be either 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. In addition, the liquid electrolyte (electrolyte solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. In addition, as the binder, for example, a rubber-based binder or a fluoride-based binder can be cited.

[0045] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may also contain at least one of a conductive material, an electrolyte, and a binder. As the negative electrode active material, for example, metal active materials such as Li and Si, carbon active materials such as graphite, and oxide active materials such as Li4Ti5O 12 etc. The shape of the negative electrode current collector is, for example, foil-shaped or mesh-shaped. Regarding the conductive material, electrolyte, and binder, it is the same as the above content.

[0046] 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 can be either a solid electrolyte or a liquid electrolyte. As the electrolyte layer, a solid electrolyte layer is preferred. The electrolyte layer may also have a spacer.

[0047] The solid electrolyte preferably contains at least one solid electrolyte selected from the group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte.

[0048] 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, carbon, etc., preferably aluminum alloy foil or aluminum foil. Aluminum alloy foil and aluminum foil can be manufactured using powder. The shape of the positive electrode current collector is, for example, foil-like or mesh-like.

[0049] The negative electrode current collector collects current from 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 and mesh. ·Battery

[0050] The laminated battery in the present disclosure is typically a lithium-ion secondary battery. As the purpose of the battery, for example, power sources of vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), pure electric vehicles (BEV), gasoline vehicles, and diesel vehicles can be cited. It is particularly preferred to be used as a driving power source for hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) or pure electric vehicles (BEV). In addition, the battery in the present disclosure can also be used as a power source for mobile bodies other than vehicles (such as railways, ships, and aircraft), and can also be used as a power source for electrical products such as information processing devices.

[0051] The present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any scheme having substantially the same configuration and exerting the same function and effect as the technical concept described in the claims of the present disclosure is included in the technical scope of the present disclosure.

Claims

1. A laminated battery comprising: an electrode body; and a laminate film covering and sealing the electrode body, The laminate film has a structure in which at least a metal layer and a fusion resin layer inside the metal layer are stacked. The laminate film has a fusion portion where the ends overlap each other and the fusion resin layers on the inner surfaces are fusion-bonded to each other. A part of the weld portion has a metal close contact portion where the metal layers are in close contact with each other over the entire region in the longitudinal direction of the weld portion.

2. The laminated battery according to claim 1, wherein The welded portion has a bent portion that is bent in an angular or arc shape, and the metal close contact portion is arranged in a region other than the bent portion.

3. The laminated battery according to claim 1 or 2, wherein: The welded portion has a plurality of the metal close contact portions.

4. A method for manufacturing a laminated battery, the laminated battery comprising an electrode body and a laminated film covering and sealing the electrode body, the laminated film having a structure in which at least a metal layer and a welding resin layer inside the metal layer are stacked, the laminated film having a welding portion in which the ends overlap each other and the welding resin layers inside are welded to each other, wherein: The manufacturing method includes a stamping step, that is, the weld portion is clamped from both sides by a pressing member and an opposing member and the weld portion is stamped to form a metal-contacting portion in which the metal layers are in close contact with each other over the entire area in the longitudinal direction of the weld 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 a glass transition temperature of the fusion resin layer.

5. The method for manufacturing a laminated battery according to claim 4, wherein: The front end of the pressing member in contact with the welded portion is curved with a curvature radius R of 0.2 mm or more and 1.68 mm or less. The front end of the opposing member in contact with the welded portion has a smooth shape.

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