Laminated battery and method for manufacturing laminated battery

Abstract

To provide a laminated battery capable of suppressing deterioration in structural efficiency.SOLUTION: A laminated battery includes an electrode body and laminate films that cover the electrode body and seal the electrode body inside. The laminate films include a fused portion in which end portions are superposed to fuse inner surfaces. The fused portion includes: an acute angle bent portion bent in a square shape or an arc shape so as to have an angle less than 90°; and a tip side region extending in a direction opposite to a bending direction at the acute bent portion in a region closer to the tip side of the fused portion than the acute bent 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 laminate film, a fused portion is formed by fusing a portion of the laminate film to enclose the electrode body, and this fused portion is folded to improve the structural efficiency of the battery.

[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] Conventionally, to improve the structural efficiency of laminated batteries, the fused portion of the laminate film has been bent at an angle of 90° or less to form a bent portion, thereby reducing the overall external size of the laminated battery. However, springback occurs at the bent portion, resulting in an angle of less than 90°, which increases the external size of the laminated battery and reduces its volumetric efficiency.

[0006] The present disclosure has been made in view of the above-described circumstances, and aims to provide a laminated battery capable of suppressing a decrease in structural efficiency, and a method for manufacturing such a laminated battery. [Means for solving the problem]

[0007] <1> An electrode body; a laminate film that covers the electrode body and encapsulates it inside, The laminate film has a fused portion where the ends are overlapped and the inner surfaces are fused together, The laminated battery has an acute-angle bent portion in which the fused portion is bent into an angular or arc shape at an angle of less than 90°, and a tip-side region that extends in a direction opposite to the bending direction of the acute-angle bent portion in a region closer to the tip of the fused portion than the acute-angle bent portion. <2> The angle of the acute bent portion is 30° or more and 75° or less. <1> 2. The laminated battery according to claim 1. <3> A method for manufacturing a laminated battery, comprising: an electrode body; and a laminate film that covers and encloses the electrode body, wherein the laminate film has edges that are overlapped with each other and have fused inner surfaces to form a fused portion, a bending step of pressing a rotating disk-shaped fulcrum roll member against the fused portion, and bending the fused portion at an angle of less than 90° around the point where the fulcrum roll member is pressed as a fulcrum to form an acute-angle bent portion, A method for manufacturing a laminated battery, wherein the fulcrum roll member has protrusions arranged circumferentially on the outer peripheral end of the disk-shaped surface that contacts the fused portion. <4> the bending step bends the fused portion while pressing an elastic roll against a portion of the fused portion where the acute-angle bent portion is to be formed from the side opposite to the side where the protrusion of the fulcrum roll member contacts; <3> A method for manufacturing the laminated battery according to claim 1. <5> The angle of the tip of the protrusion is 20° or more and 45° or less. <3> or <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 capable of suppressing a decrease in structural efficiency, and a method for manufacturing the laminated battery. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view illustrating a laminated battery according to an embodiment of the present invention. [Figure 2] 3 is a schematic cross-sectional view showing angles of each part in a fused portion of a laminate film of a laminated battery according to the present embodiment. FIG. [Figure 3] FIG. 2 is a schematic cross-sectional view illustrating another aspect of the laminated battery according to the present embodiment. [Figure 4] 1A to 1C are schematic cross-sectional views illustrating a method for manufacturing a laminated battery according to an embodiment of the present invention. [Figure 5] 3 is a schematic cross-sectional view showing the angles of the various portions of the protrusions of the supporting roll member used in the manufacturing method of the laminated battery according to the embodiment. FIG. [Figure 6] FIG. 1 is a schematic cross-sectional view showing an example of a solid-state battery. 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 encloses the electrode assembly, and the laminate film has a fused portion where edges are overlapped and the inner surfaces are fused together. The fused portion has an acute-angle bent portion that is bent into an angular or arc shape at an angle of less than 90°, and a tip-side region that extends in a direction opposite to the bending direction of the acute-angle bent portion, in a region closer to the tip of the fused portion than the acute-angle bent 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 this embodiment. The laminated battery 10 shown in FIG. 1 includes an electrode assembly 2 and a laminate film 4 that covers and encases the electrode assembly 2. The laminate film 4 has a fused portion 40 formed by overlapping edges of the laminate film 4 and fusing the inner surfaces. The fused portion 40 has an acute-angle bent portion 42 that is bent into a square or arc shape at an angle of less than 90°. Furthermore, the fused portion 40 has a tip-side region 44 that extends in a direction opposite to the bending direction of the acute-angle bent portion 42, in a region closer to the tip 40a of the fused portion 40 than the acute-angle bent portion 42.

[0013] The laminated battery 10 having the above configuration suppresses a decrease in the structural efficiency of the laminated battery 10 due to springback at the acute-angle bent portion 42 of the fused portion 40. The reason for this effect is presumed to be as follows.

[0014] First, we will explain conventional laminated batteries. Conventionally, to improve the structural efficiency of laminated batteries, the fused portion of the laminate film is folded at an angle of 90° or less to form a bent portion, thereby reducing the overall external size of the laminated battery. However, springback occurs at the bent portion, resulting in an angle of less than 90°, which increases the external size of the laminated battery and reduces its volumetric efficiency.

[0015] In contrast, the laminated battery 10 according to this embodiment has an acute-angle bent portion 42 bent at an angle of less than 90° in the fused portion 40, and a tip region 44 located closer to the tip 40a than the acute-angle bent portion 42 is shaped to extend in a direction opposite to the bending direction of the acute-angle bent portion 42. This allows the amount of springback to be generated at the acute-angle bent portion 42 to be taken into consideration when determining the angle of warping of the tip region 44, i.e., the angle at which the tip region 44 extends in a direction opposite to the bending direction of the acute-angle bent portion 42. Therefore, even if springback occurs at the acute-angle bent portion 42, adjusting the angle of warping of the tip region 44 can suppress a decrease in the volumetric efficiency of the laminated battery 10.

[0016] As described above, according to the laminated battery according to the embodiment of the present disclosure, it is possible to suppress a decrease in the structural efficiency of the laminated battery due to springback at the acute angle bends of the fused portions.

[0017] -Angles of each part in the fused area Here, preferred angles of each portion in the fused portion of the laminate film in the laminated battery according to the embodiment of the present disclosure will be described. The angle of the acute bent portion bent into a square or arc (angle a shown in FIG. 2) may be less than 90°, and is preferably 75° or less, and more preferably 60° or less, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. On the other hand, the lower limit of the angle of the acute bent portion is preferably 30° or more, and more preferably 40° or more, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. The angle of the acute bent portion is preferably 30° or more and 75° or less, and more preferably 40° or more and 60° or less. The angle of the acute-angle bent portion refers to angle a shown in Fig. 2. In other words, it refers to the angle formed by the direction in which the fused portion 40 extends from the base of the fused portion 40 (i.e., the end of the fused portion 40 on the electrode body 2 side) and the direction in which the region of the fused portion 40 on the tip 40a side of the acute-angle bent portion 42 extends from the acute-angle bent portion 42. An acute bend has a shape that is bent in an angular or arc shape, where angular means a shape with a corner and arc means a curved shape without a corner.

[0018] The angle of the tip region (angle b shown in FIG. 2 ), which extends in a direction opposite to the bending direction of the acute-angle bent portion in the region closer to the tip of the fused portion than the acute-angle bent portion, is preferably 95° or less, and more preferably 90° or less, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. On the other hand, the lower limit of the angle of the tip region is preferably 80° or more, and more preferably 85° or more, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. The angle of the tip region is preferably 80° or more and 95° or less, and more preferably 85° or more and 90° or less. The angle of the tip region that extends in a direction opposite to the bending direction at the acute-angle bent portion of the fused portion refers to angle b shown in Fig. 2. In other words, it refers to the angle formed by the direction in which the fused portion 40 extends from the base of the fused portion 40 (i.e., the end of the fused portion 40 on the electrode body 2 side) and the direction in which the tip region 44 that extends in a direction opposite to the bending direction at the acute-angle bent portion 42 of the fused portion 40 extends.

[0019] Other aspects The fused portion may have one or more other bent portions in addition to the acute angle bent portion. FIG. 3 is a schematic cross-sectional view illustrating another aspect of the laminated battery according to this embodiment. The laminated battery 10A shown in FIG. 3 includes an electrode assembly 2 and a laminate film 4 that covers and encloses the electrode assembly 2. The laminate film 4 has a fused portion 400 formed by overlapping edges of the laminate film 4 and fusing the inner surfaces. The fused portion 400 has an acute-angle bent portion 420 that is bent into a square or arc shape at an angle of less than 90°. Furthermore, the fused portion 400 has a tip region 440 that extends in a direction opposite to the bending direction of the acute-angle bent portion 420, in a region closer to the tip of the fused portion 400 than the acute-angle bent portion 420. Furthermore, the fused portion 400 has a bent portion 460 that is bent into a square or arc shape at an angle of approximately 0° in the tip region 440, and the tip region 440 of the fused portion 400 has a folded-back shape. As described above, the laminated battery 10A shown in FIG. 3 has two bent portions (acute-angle bent portion 420 and bent portion 460) in the fused portion 400 of the laminated film 4.

[0020] <Laminated battery manufacturing method> Next, a method for manufacturing a laminated battery according to an embodiment of the present disclosure will be described.

[0021] A manufacturing method of 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 the electrode body and encloses it inside, and the laminate film has its ends overlapped and its inner surface fused to form a fused portion. This method for manufacturing a laminated battery includes a bending step in which a rotating disk-shaped fulcrum roll member is pressed against the fused portion, and the fused portion is bent at an angle of less than 90° using the point where the fulcrum roll member is pressed as a fulcrum to form an acute-angle bent portion. The fulcrum roll member has protrusions arranged circumferentially (preferably continuously) on the outer peripheral edge of the disk-shaped surface that contacts the fused portion.

[0022] An embodiment of a method for manufacturing a laminated battery according to the present disclosure will now be described with reference to the drawings. Figure 4 is a schematic cross-sectional view illustrating the method for manufacturing a laminated battery according to this embodiment. The laminated battery 10 shown in Fig. 4 has an electrode body 2 and a laminate film 4 that covers and encloses the electrode body 2. The laminated film 4 has a fused portion 40 where the ends are overlapped and the inner surfaces are fused together.

[0023] The manufacturing method for a laminated battery includes a bending step of forming an acute-angle bent portion 42 in the fused portion 40 of the laminate film 4. In the bending step, a disk-shaped fulcrum roll member 6 that rotates around an axis 60 is pressed against the fused portion 40 where no acute-angle bent portion is formed, and the fused portion 40 is bent at an angle of less than 90° using the point where the fulcrum roll member 6 is pressed as a fulcrum, thereby forming the acute-angle bent portion 42. The fulcrum roll member 6 has protrusions 62 at the end of its disk-like shape on the surface that contacts the fused portion 40. The protrusions 62 are continuously arranged in the circumferential direction on the outer peripheral end of the disk-like shape of the fulcrum roll member 6.

[0024] As shown in Figure 4, by bending the fused portion 40 while pressing a fulcrum roll member 6 having a protrusion 62 at its end, it is possible to form an acute-angle bent portion 42 with an angle of less than 90° even when the fulcrum roll member 6 is pressed against the fused portion 40 in an upright position. If an attempt is made to form an acute-angle bend of less than 90° in the fused portion of the laminate film using a fulcrum roll member without protrusions on its end, the fulcrum roll member must be pressed against the fused portion at an angle, which requires space to tilt the fulcrum roll member, thereby increasing the distance from the electrode assembly to the acute-angle bend, thereby reducing the structural efficiency of the battery. However, by forming the acute-angle bent portion 42 using a fulcrum roll member 6 having protrusions 62 at its end, it is not necessary to tilt the fulcrum roll member 6, and therefore the distance from the electrode body 2 to the acute-angle bent portion 42 can be shortened. In other words, by providing the protrusions 62 on the fulcrum roll member 6 and bending the fused portion 40, it is possible to form the acute-angle bent portion 42 with an angle of less than 90° even in a narrow space. As a result, the structural efficiency of the battery can be improved.

[0025] Additionally, an elastic roll 64, the surface of which contacts the fused portion being made of an elastic material (e.g., rubber), is pressed against the portion of the fused portion 40 where the acute-angle bent portion 42 is to be formed, from the side opposite to the side where the protrusion 62 of the fulcrum roll member 6 contacts. By performing bending while pressing the elastic roll 64 against a position facing the protrusion 42 of the fulcrum roll member 6 across the portion of the fused portion 40 where the acute-angle bent portion 42 is to be formed, the acute-angle bent portion 42 can be formed while applying high pressure, and the occurrence of springback in the acute-angle bent portion 42 after formation can be further suppressed.

[0026] Furthermore, an opposing roll 66 is pressed against the fused portion 40 at a position opposite the fulcrum roll member 6, sandwiching the fused portion 40, on the base side of the fused portion 40 from the point where the acute angle bend 42 is formed (i.e., the electrode body 2 side of the fused portion 40).

[0027] -Angles of each part of the protrusion Here, preferred angles of each portion of the protrusion of the supporting roll member used in the manufacturing method of a laminated battery according to an embodiment of the present disclosure will be described. The angle of the tip of the projection (angle c shown in FIG. 5) is preferably 45° or less, and more preferably 40° or less, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. On the other hand, the lower limit of the angle of the tip of the projection is preferably 20° or more, and more preferably 25° or more, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. The angle of the tip of the projection is preferably 20° or more and 45° or less, and more preferably 25° or more and 40° or less. The angle of the tip of the projection means angle c shown in Fig. 5. In other words, it means the angle of the pointed tip of the projection 62 of the supporting roll member 6.

[0028] The angle from the end of the disk shape of the fulcrum roll member toward the tip of the protrusion (angle d shown in FIG. 5) is preferably 45° or less, and more preferably 40° or less, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. On the other hand, the lower limit of the angle from the end of the disk shape of the fulcrum roll member toward the tip of the protrusion is preferably 20° or more, and more preferably 25° or more, from the viewpoint of suppressing a decrease in the structural efficiency of the laminated battery. The angle is preferably 20° or more and 45° or less, and more preferably 25° or more and 40° or less. The angle in the direction from the end of the disk shape of the fulcrum roll member toward the tip of the protrusion means angle d shown in Fig. 5. In other words, it means the angle formed by the direction from the end 6e of the disk shape of the fulcrum roll member 6 toward the tip of the protrusion 62 and the planar direction of the disk-shaped fulcrum roll member 6.

[0029] (Battery components) Next, the electrode body and laminate film that constitute the laminate battery according to this embodiment will be described.

[0030] (1) Laminate film The laminate film used is, for example, a film having a three-layer structure including a metal layer, a protective resin layer on the outside of the metal layer, and a fusion resin layer on the inside of the metal layer.

[0031] 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.

[0032] (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.

[0033] 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.

[0034] 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.

[0035] 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 satisfy the conditions 0.5≦x≦1.5, 0.5≦y≦1.0, 1≦α<2, and 0<β≦1.)

[0036] 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.

[0037] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include M1 x M2 yO2 (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 0 < x + y ≦ 2). Examples include composite oxides represented by this formula.

[0038] 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 include composite oxides represented by this formula, and specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2, etc.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] As a sulfide solid electrolyte, it is preferable to contain sulfur (S) as the main component of the anion element, and further preferably contain, for example, Li element, A element, and S element. The A element is at least one selected from the group consisting of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In. The sulfide solid electrolyte may further contain at least one of O and halogen elements. Examples of the halogen element (X) include F, Cl, Br, I, etc. The composition of the sulfide solid electrolyte is not particularly limited, and examples include xLi2S·(100 - x)P2S5 (70 ≤ x ≤ 80), yLiI·zLiBr·(100 - y - z)(xLi2S·(1 - x)P2S5) (0.7 ≤ x ≤ 0.8, 0 ≤ y ≤ 30, 0 ≤ z ≤ 30). The sulfide solid electrolyte may have a composition represented by the following general formula (1). Li 4-x Ge 1-x P x S4(0 < x < 1) ··· Formula (1) In Formula (1), at least a part of Ge may be substituted by at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. Also, at least a part of P may be substituted by at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. A part of Li may be substituted by at least one selected from the group consisting of Na, K, Mg, Ca, and Zn. A part of S may be substituted by a halogen. The halogen is at least one of F, Cl, Br, and I.

[0045] As an oxide solid electrolyte, it is preferable to contain oxygen (O) as the main component of the anion element, and for example, it may contain Li, Q element (Q represents at least one of Nb, B, Al, Si, P, Ti, Zr, Mo, W, and S), and O. Examples of the oxide solid electrolyte include garnet-type solid electrolyte, perovskite-type solid electrolyte, NASICON-type solid electrolyte, Li-P-O-based solid electrolyte, Li-B-O-based solid electrolyte, etc. Examples of the garnet-type solid electrolyte include, for example, Li7La3Zr2O 12 、Li 7-x La3(Zr2-x Nb x )O 12 (0 ≦ x ≦ 2), Li5La3Nb2O 12 etc. Examples of perovskite-type solid electrolytes include (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, etc. Examples of NASICON-type solid electrolytes include Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, etc. Examples of Li-P-O-based solid electrolytes include Li3PO4, LIPON (a compound in which part of the O in Li3PO4 is replaced by N), and examples of Li-B-O-based solid electrolytes include Li3BO3, a compound in which part of the O in Li3BO3 is replaced by C, etc.

[0046] As a halide solid electrolyte, a solid electrolyte containing Li, M, and X (M represents at least one of Ti, Al, and Y, and X represents F, Cl, or Br) is suitable. Specifically, Li 6-3z Y z X6 (X represents Cl or Br, and z satisfies 0 < z < 2), Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≦ 1.5) is preferred. Among Li 6-3z Y z X6, Li3YX6 (X represents Cl or Br) is more preferred in terms of excellent lithium ion conductivity, and further Li3YCl6 is preferred. Also, Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≦ 1.5) is preferably included together with a solid electrolyte such as a sulfide solid electrolyte from viewpoints such as suppressing oxidative decomposition of the sulfide solid electrolyte.

[0047] 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.

[0048] 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.

[0049] ·Battery structure The structure of a solid-state battery is a laminated structure of a positive electrode, a solid electrolyte layer, and a negative electrode. The solid-state battery includes so-called all-solid-state batteries that use a solid electrolyte as the electrolyte, and the solid electrolyte may contain an electrolytic solution in an amount of less than 10 mass % relative to the total amount of the electrolyte. The solid electrolyte may also be a composite solid electrolyte containing an inorganic solid electrolyte and a polymer electrolyte.

[0050] The positive electrode has a positive electrode active material layer and a current collector, and the negative electrode has a negative electrode active material layer and a current collector. The solid electrolyte layer may have a single layer structure or a multi-layer structure of two or more layers. The solid-state battery may have, for example, a cross-sectional structure shown in FIG. 6, and the solid electrolyte layer B may have a two-layer structure as shown in FIG. 6. FIG. 6 is a schematic cross-sectional view showing an example of a solid-state battery. The solid-state battery shown in FIG. 6 has a negative electrode including a negative electrode current collector 113 and a negative electrode active material layer A, a solid electrolyte layer B, and a positive electrode including a positive electrode current collector 115 and a positive electrode active material layer C. The negative electrode active material layer A includes a negative electrode active material 101, a conductive additive 105, and a binder 109. The positive electrode active material layer C includes a coated positive electrode active material 103, a conductive additive 107, and a binder 111, and the surface of the coated positive electrode active material 103 is coated with an LTAF electrolyte or a LiNbO electrolyte. The solid-state battery may be configured by sealing the end faces (side faces) of the laminated structure of the positive electrode / solid electrolyte layer / negative electrode with a resin. The current collector of the electrode may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on the surface.

[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 automobiles, and diesel-powered automobiles. 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 supporting roll member, 10, 10A laminated battery, 40, 400 fused portion, 40a tip, 42, 420 acute angle bent portion, 44, 440 tip side region, 460 bent portion, 60 shaft, 62 protrusion, 64 elastic roll, 66 opposing roll, 101 negative electrode active material, 103 coated positive electrode active material, 105, 107 conductive additive, 109, 111 binder, 113 negative electrode current collector, 115 positive electrode current collector, A negative electrode active material layer, B solid electrolyte layer, C positive electrode active material layer

Claims

1. An electrode body; a laminate film that covers the electrode body and encapsulates it inside, The laminate film has a fused portion where the ends are overlapped and the inner surfaces are fused together, the fused portion has an acute-angle bent portion bent in an angular or arc shape at an angle of 30° or more and 75° or less, and a tip-side region extending in a direction opposite to the bending direction of the acute-angle bent portion in a region on the tip side of the fused portion relative to the acute-angle bent portion, The fused portion has a tip portion located closer to the electrode body than the acute-angle bent portion in a region closer to the tip of the fused portion than the acute-angle bent portion.

2. A method for manufacturing a laminated battery comprising: an electrode body; and a laminate film that covers and encloses the electrode body, the laminate film having a fused portion where end portions of the laminate film are overlapped and inner surfaces are fused, a bending step of pressing a rotating disk-shaped fulcrum roll member against the fused portion, and bending the fused portion at an angle of 30° to 75° with the point where the fulcrum roll member is pressed as a fulcrum to form an acute-angle bent portion, the support roll member has protrusions arranged in a circumferential direction at an outer peripheral end of the disk-shaped surface that contacts the fused portion, The bending step includes bending the fused portion so that the fused portion has a tip portion that is located closer to the electrode body than the acute-angle bend portion in a region closer to the tip of the fused portion than the acute-angle bend portion.

3. 3. The method for manufacturing a laminated battery according to claim 2, wherein the bending step involves bending the fused portion while pressing an elastic roll against the portion where the acute angle bend is to be formed on the fused portion from the side opposite to the side where the protrusion of the fulcrum roll member contacts.

4. 4. The method for manufacturing a laminated battery according to claim 2, wherein the angle of the tip of the projection is 20 degrees or more and 45 degrees or less.

Images