Laminated battery and method for manufacturing laminated battery

Abstract

The invention relates to a laminated battery and a method for manufacturing the laminated battery. A laminated battery includes an electrode body, and a laminated film covering the electrode body and enclosing the electrode body, the laminated film having a welded portion in which end portions overlap each other and an inner surface is welded. The welded section has an acute-angled curved section that is curved in an angular or arcuate shape so as to have an angle of less than 90 DEG, and a distal-end-side region that extends in a direction opposite to the bending direction of the acute-angled curved section in a region located on the distal-end side of the welded section than the acute-angled curved section.

Description

Technical Field

[0001] The present disclosure relates to a stacked battery and a method for manufacturing the stacked 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, and the welded portion is bent in order to improve the structural efficiency of the battery.

[0003] For example, patent document 1 discloses a method for manufacturing a secondary battery, which is a method for manufacturing a secondary battery having a folded portion at at least one end in an outer packaging body that has undergone a lamination process, the method comprising: a process of making a pressing plate abut against the base point of the folding of the end of the outer packaging body; and after the abutting process, a process of sliding the pressing plate and an extrusion plate arranged at a position opposite to the pressing plate in a manner of clamping the end, bending the end around the base point, and forming the folded portion by clamping the end using the pressing plate and the extrusion plate, wherein the surface sliding relative to the end of the extrusion plate comprises an inclined surface for bending the end and a clamping surface for clamping the end, the inclined surface being inclined in a cross-section orthogonal to the width direction of the extrusion plate in such a manner that the cross-sectional area of ​​the extrusion plate becomes narrower in the sliding direction, and the inclined surface is inclined in the width direction.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-200973 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the past, in order to improve the structural efficiency of the stacked battery, the welded portion of the stacked film was bent to an angle of about 90 degrees to form a curved portion, so that the overall size of the stacked battery was reduced. However, springback occurs at the curved portion, resulting in the curved portion being at an angle shallower than 90 degrees, and sometimes the size of the stacked battery becomes larger, and the volumetric efficiency is reduced.

[0009] 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 stacked battery and a method for manufacturing the stacked battery that can suppress a decrease in structural efficiency.

[0010] Means for solving problems

[0011] <1> A stacked battery comprising an electrode body and a stacked film covering and sealing the electrode body, the stacked film having a welded portion whose ends overlap each other and whose inner surfaces are welded, the welded portion having an acute angled bend bent into an angle of less than 90° to form an angle or an arc, and a top end side region extending in a direction opposite to the bending direction of the acute angled bend in a region located on the top end side of the welded portion relative to the acute angled bend.

[0012] <2> The stacked battery according to <1>, wherein the acute-angle bent portion has an angle of 30° to 75°.

[0013] <3> A method for manufacturing a stacked battery, the stacked battery comprising an electrode body and a stacked film covering and sealing the electrode body, the stacked film having a fusion portion in which ends overlap each other and inner surfaces are fused, the manufacturing method comprising a bending step, wherein a rotating disc-shaped fulcrum roller member is brought into contact with the fusion portion, the fusion portion is bent at an angle of less than 90° using the portion abutted by the fulcrum roller member as a fulcrum to form an acute-angle bend portion, the fulcrum roller member having a circumferentially arranged protrusion on the outer peripheral end of the disc-shaped shape on the side of the surface in contact with the fusion portion.

[0014] <4> The method for manufacturing a stacked battery according to <3>, wherein in the bending step, the weld portion is bent while contacting an elastic roller from a side opposite to a side where the protrusion of the fulcrum roller member contacts a portion of the weld portion where the acute-angle bent portion is formed.

[0015] <5> The method for producing a stacked battery according to <3> or <4>, wherein the angle of the tip of the protrusion is 20° to 45°.

[0016] Effects of the Invention

[0017] According to the present disclosure, it is possible to provide a stacked battery capable of suppressing a decrease in structural efficiency and a method for manufacturing the stacked battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic cross-sectional view illustrating one embodiment of the stacked battery according to the present disclosure.

[0019] Figure 2 It is a schematic cross-sectional view showing the angles of various parts in the welded portion of the laminated film of the above embodiment of the laminated battery according to the present disclosure.

[0020] Figure 3 This is a schematic cross-sectional view illustrating another embodiment of the laminated battery according to the present disclosure.

[0021] Figure 4 This is a schematic cross-sectional view illustrating one embodiment of a method for producing a laminated battery according to the present disclosure.

[0022] Figure 5 It is a schematic cross-sectional view showing the angles of various parts in the protrusion of the fulcrum roller member used in the above embodiment of the method for manufacturing a laminated battery according to the present disclosure.

[0023] Figure 6 This is a schematic cross-sectional view showing an example of a solid battery.

[0024] Description of Reference Numerals

[0025] 2 electrode body, 4 laminated film (laminated film packaging body), 6 fulcrum roller member, 10, 10A laminated battery, 40, 400 welding portion, 40a top end, 42, 420 acute angle bending portion, 44, 440 top end side region, 460 bending portion, 60 axis, 62 protrusion, 64 elastic roller, 66 opposing roller, 101 negative electrode active material, 103 coated positive electrode active material, 105, 107 conductive aid, 109, 111 binder, 113 negative electrode collector, 115 positive electrode collector, A negative electrode active material layer, B solid electrolyte layer, C positive electrode active material layer DETAILED DESCRIPTION

[0026] <Laminated battery>

[0027] The laminated battery according to the embodiment of the present disclosure comprises an electrode body and a laminated film covering and sealing the electrode body, wherein the laminated film has a welded portion whose ends overlap each other and whose inner surfaces are welded. Furthermore, the welded portion comprises an acute angled portion bent into an angle or an arc shape at an angle less than 90°, and a top end side region extending in a direction opposite to the bending direction of the acute angled portion in a region located on the top end side of the welded portion relative to the acute angled portion.

[0028] Hereinafter, one embodiment of the stacked battery according to the present disclosure will be described with reference to the drawings.

[0029] Each of the following drawings is a schematic diagram, and the size and shape of each part are exaggerated as appropriate for easier understanding.

[0030] Figure 1 This is a schematic cross-sectional view illustrating a stacked battery according to this embodiment.

[0031] Figure 1The stacked battery 10 shown has an electrode body 2, and a stacked film 4 (hereinafter sometimes referred to as a "stacked film package body 4") that covers the electrode body 2 and seals the inside. The stacked film package body 4 has a welded portion 40 whose ends overlap each other and whose inner surfaces are welded. Furthermore, the welded portion 40 has an acute-angled bend 42 that is bent into an angle or arc shape at an angle less than 90°. Furthermore, the welded portion 40 has a top end side region 44 that extends in a direction opposite to the bending direction (bending direction) of the acute-angled bend 42 in an area located on the top end 40a side of the welded portion 40 relative to the acute-angled bend 42. Specifically, the "stacked film package body 4 has a welded portion 40 whose ends overlap each other and whose inner surfaces are welded" means that the stacked film package body 4 has a first stacked film portion ( Figure 1 The second laminated film portion ( Figure 1 The laminated film package body 4 has a welded portion 40 where an end portion of the first laminated film portion overlaps an end portion of the second laminated film portion and the inner surfaces are welded.

[0032] According to the laminated battery 10 having the above-described structure, a decrease in the structural efficiency of the laminated battery 10 due to springback at the acute-angle bent portion 42 of the weld 40 is suppressed. The reason for this effect is presumably as follows.

[0033] First, the phenomenon that occurs in the case of conventional stacked batteries is described. In the past, in order to improve the structural efficiency of stacked batteries, the welded portion of the stacked film was bent to an angle of about 90° to form a bent portion, so that the overall size of the stacked battery was reduced. However, springback occurs in the bent portion, and as a result, the bent portion becomes an angle shallower than 90°, and sometimes the size of the stacked battery becomes larger, and the volumetric efficiency decreases.

[0034] The stacked battery 10 involved in this embodiment has an acute-angle bend portion 42 bent in a manner to form an angle less than 90° in the welding portion 40, and the top side region 44 located on the top end 40a side compared to the acute-angle bend portion 42 is shaped to extend in a direction opposite to the bending direction in the acute-angle bend portion 42. More specifically, the angle less than 90° is formed between the direction in which the welding portion 40 extends from the acute-angle bend portion 42 toward the root of the welding portion 40 (that is, the end of the welding portion 40 on the electrode body 2 side) and the direction in which the region of the welding portion 40 located on the top end 40a side compared to the acute-angle bend portion 42 (hereinafter also referred to as region B) extends from the acute-angle bend portion 42. In addition, the region from the root of the welding portion 40 to the acute-angle bend portion 42 will also be referred to as region A hereinafter. Moreover, the direction in which region B extends from the acute-angle bend portion 42 is the direction in which region A extends from the root of the welding portion 40 ( Figure 1In the case of ( ) counterclockwise rotation of more than 90° to 180°. Region B is connected to the top side region 44. The top side region 44 extends from the base of the region B side in a direction such that the direction in which region B extends from the acute angle bend 42 is in the same direction as the rotation direction in the acute angle bend 42 ( Figure 1 The opposite direction of rotation (counterclockwise in the case of Figure 1 In the case of rotation, it is clockwise. It should be noted that the rotation direction (not the reflex angle) mentioned here refers to the rotation direction of the rotation angle within 180°. Therefore, even if the angle between region A and region B is bent to a smaller angle of less than 90°, the top side region 44 can be prevented from colliding with the electrode body. Therefore, the acute angle bend 42 is fully bent to avoid the occurrence of springback.

[0035] 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 in the acute-angle bent portion of the welded portion.

[0036] ·Angles of each part in the weld

[0037] Here, preferred angles of each portion in the welded portion of the laminate film package in the laminated battery according to the embodiment of the present disclosure will be described.

[0038] The angle of the acute bend that is bent into an angle or an arc ( Figure 2 The angle a) shown in the figure only needs to be less than 90°, and from the viewpoint of suppressing the reduction in the structural efficiency of the stacked battery, it is preferably 75° or less, and more preferably 60° or less. On the other hand, from the viewpoint of suppressing the reduction in the structural efficiency of the stacked battery, the lower limit of the angle of the acute angle bend is preferably 30° or more, and more preferably 40° or more. The angle of the acute angle bend is preferably 30° or more and 75° or less, and more preferably 40° or more and 60° or less.

[0039] Furthermore, the angle of the acute angle bend is Figure 2 That is, it refers to the angle formed by the direction in which the weld 40 extends from the acute-angle bend 42 toward the root of the weld 40 (i.e., the end of the weld 40 on the electrode body 2 side) and the direction in which the region of the weld 40 located on the tip 40a side relative to the acute-angle bend 42 (the region B described above) extends from the acute-angle bend 42.

[0040] The acute angle bent portion has a shape that is bent into an angle or an arc shape. The so-called angle shape refers to a shape having an angle, and the so-called arc shape refers to a curved shape without an angle.

[0041] From the viewpoint of suppressing the decrease in the structural efficiency of the stacked battery, the angle ( Figure 2 The angle b) shown is preferably 95° or less, more preferably 90° or less. On the other hand, from the viewpoint of avoiding collision with the electrode body, the lower limit of the angle of the top side region is preferably 80° or more, more preferably 85° or more. The angle of the top side region is preferably 80° or more and 95° or less, more preferably 85° or more and 90° or less.

[0042] It should be noted that the angle of the tip end region of the weld portion that is bent and extended in the direction opposite to the bending direction of the acute angle bent portion is Figure 2 The angle b shown (the angle of the top end region of the weld extending in the direction opposite to the bending direction of the acute angle bend portion) is Figure 2 That is, it refers to the angle formed by the direction in which the weld 40 extends from the acute-angle bend 42 toward the root of the weld 40 (i.e., the end of the weld 40 on the electrode body 2 side) and the direction in which the top end side region 44 of the weld 40 that is bent and extends in the direction opposite to the bending direction of the acute-angle bend 42 extends.

[0043] Another solution

[0044] The welded portion may have one or more other bent portions in addition to the acute-angle bent portion.

[0045] Figure 3 This is a schematic cross-sectional view illustrating another aspect of the stacked battery according to the present embodiment.

[0046] Figure 3 The laminated battery 10A shown has an electrode body 2 and a laminated film 4 covering and sealing the electrode body 2. The laminated film 4 has a welded portion 400 in which the ends overlap each other and the inner surfaces are welded. More specifically, the laminated film 4 has a first laminated film portion ( Figure 3 The second laminated film portion ( Figure 3(as shown in the lower middle side), the laminated film 4 has a welded portion 400 in which the end of the first laminated film portion overlaps with the end of the second laminated film portion and the inner surface is welded. The welded portion 400 has an acute-angle bend portion 420 that is bent into an angle or an arc shape in a manner that becomes an angle less than 90°. Furthermore, the welded portion 400 has a top side region 440 that extends in a direction opposite to (divided from, different from) the bending direction of the acute-angle bend portion 420 in an area located on the top side of the welded portion 400 compared to the acute-angle bend portion 420. Furthermore, the welded portion 400 has a bend portion 460 that is bent into an angle or an arc shape in a manner that becomes an angle of approximately 0° in the top side region 440, and has a shape in which the top side region 440 of the welded portion 400 is folded. In this way, Figure 3 The stacked battery 10A shown has two bends (acute bend 420 and bend 460) at the weld 400 of the stacked film 4. The top end region 440 having the folded portion 460 is basically an integral structure, and even if it has such a folded portion, the top end region is included in the category of "top end region extending in the direction opposite to the bending direction of the acute bend".

[0047] <Method for manufacturing laminated battery>

[0048] Next, a method for manufacturing a stacked battery according to an embodiment of the present disclosure will be described.

[0049] A method for manufacturing a laminated battery according to an embodiment of the present disclosure is a method for manufacturing a laminated battery including an electrode body and a laminated film covering and sealing the electrode body, wherein the laminated film has a welded portion in which ends overlap each other and inner surfaces are welded.

[0050] The manufacturing method of the laminated battery includes a bending step, wherein a rotating disk-shaped fulcrum roller member is brought into contact with the welded portion, and the welded portion is bent at an angle less than 90 degrees with the portion where the fulcrum roller member contacts as a fulcrum to form an acute angle bent portion. Furthermore, the fulcrum roller member has protrusions arranged in the circumferential direction (preferably continuously) at the outer peripheral end of the disk-shaped shape of the surface on the side in contact with the welded portion.

[0051] Hereinafter, one embodiment of a method for producing a laminated battery according to the present disclosure will be described with reference to the drawings. Figure 4 This is a schematic cross-sectional view illustrating a method for manufacturing a stacked battery according to the present embodiment.

[0052] Figure 4 The laminated battery 10 shown has an electrode body 2 and a laminate film 4 covering and sealing the electrode body 2. The laminate film 4 has a first laminate film portion and a second laminate film portion, and the laminate film package 4 has a welded portion 40 where the end of the first laminate film portion overlaps the end of the second laminate film portion and the inner surface is welded.

[0053] The method for manufacturing a laminated battery includes a bending step of forming an acute angle bent portion 42 at a welded portion 40 of a laminated film 4. In the bending step, a disc-shaped fulcrum roller member 6 rotating about an axis 60 is brought into contact with the welded portion 40 where an acute angle bent portion has not yet been formed, and the welded portion 40 is bent at an angle less than 90° with the part brought into contact with the fulcrum roller member 6 as a fulcrum, thereby forming an acute angle bent portion 42. The fulcrum roller member 6 has a protrusion 62 at the end of the disc-shaped shape of the surface on the side in contact with the welded portion 40. The protrusion 62 is continuously arranged in the circumferential direction at the outer peripheral end of the disc-shaped shape of the fulcrum roller member 6.

[0054] like Figure 4 As shown, by bending the weld 40 while abutting the fulcrum roller member 6 having the protrusion 62 at the end, an acute angle bend 42 with an angle less than 90° can be formed even when the fulcrum roller member 6 abuts against the weld 40 in an upright state.

[0055] If a fulcrum roller member without a protrusion at the end is used to form an acute angle bend of less than 90° at the welded portion of the laminated film, the fulcrum roller member needs to be tilted so as to abut against the welded portion. In this case, a space is required for tilting the fulcrum roller member, and the distance from the electrode body to the acute angle bend becomes longer, resulting in a decrease in the structural efficiency of the battery.

[0056] However, by using the fulcrum roller member 6 having the protrusion 62 at the end to form the acute angle bent portion 42, it is not necessary to tilt the fulcrum roller member 6, so that the distance from the electrode body 2 to the acute angle bent portion 42 can be shortened. That is, by providing the protrusion 62 on the fulcrum roller member 6 to bend the welded portion 40, the acute angle bent portion 42 with an angle of less than 90° can be formed even in a narrow space. As a result, the structural efficiency of the battery can be improved.

[0057] In addition, an elastic roller 64 whose surface in contact with the welded portion is made of an elastic member (e.g., rubber) is brought into contact with the portion of the welded portion 40 where the acute-angle bent portion 42 is formed, from the side opposite to the side where the protrusion 62 of the fulcrum roller member 6 is in contact. By bending the portion of the welded portion 40 where the acute-angle bent portion 42 is formed while bringing the elastic roller 64 into contact at a position facing the protrusion 62 of the fulcrum roller member 6 while the portion is sandwiched between the elastic roller 64 and the protrusion 62, the acute-angle bent portion 42 can be formed while applying a high pressure, and the occurrence of springback in the acute-angle bent portion 42 after formation can be further suppressed.

[0058] Furthermore, on the root side of the weld 40 where the acute-angle bent portion 42 is formed (ie, on the electrode body 2 side of the weld 40 ), the opposing roller 66 abuts against the fulcrum roller member 6 while sandwiching the weld 40 .

[0059] ·Angles of each part of the protrusion

[0060] Here, preferred angles of various portions of the protrusion of the fulcrum roller member used in the method for producing a laminated battery according to an embodiment of the present disclosure will be described.

[0061] From the viewpoint of suppressing the decrease in the structural efficiency of the stacked battery, the angle of the top of the protrusion ( Figure 5 The angle c) shown is preferably 45° or less, more preferably 40° or less. On the other hand, from the viewpoint of suppressing the reduction in the structural efficiency of the stacked battery, the lower limit of the angle of the top of the protrusion is preferably 20° or more, more preferably 25° or more. The angle of the top of the protrusion is preferably 20° or more and 45° or less, more preferably 25° or more and 40° or less.

[0062] It should be noted that the angle of the top of the protrusion refers to Figure 5 The angle c shown is, that is, the angle of the pointed tip portion of the protrusion 62 of the fulcrum roller member 6 .

[0063] From the viewpoint of suppressing the decrease in the structural efficiency of the stacked battery, the angle ( Figure 5 The angle d) shown is preferably 45° or less, more preferably 40° or less. On the other hand, from the viewpoint of suppressing the reduction in the structural efficiency of the stacked battery, the lower limit of the angle in the direction from the end of the disc shape toward the top of the protrusion in the fulcrum roller member is preferably 20° or more, more preferably 25° or more. The angle is preferably 20° or more and 45° or less, more preferably 25° or more and 40° or less.

[0064] The angle of the fulcrum roller member in the direction from the end of the disk shape toward the tip of the protrusion is Figure 5 That is, it refers to the angle formed by the direction from the disk-shaped end 6e of the fulcrum roller member 6 toward the tip of the protrusion 62 and the direction perpendicular to the disk surface of the disk-shaped fulcrum roller member 6.

[0065] (Battery components)

[0066] Next, the electrode body and the laminated film laminated film package constituting the laminated battery according to the present embodiment will be described.

[0067] (1) Laminated film

[0068] The laminate film (including the first laminate film portion and the second laminate film portion) in the laminate film package uses, for example, a three-layer structure film having a metal layer, a protective resin layer outside the metal layer, and a fusion resin layer inside the metal layer.

[0069] As the material of the welding resin layer, for example, olefin resins such as polypropylene (PP) and polyethylene (PE) can be listed. As the material of the metal layer, for example, aluminum, aluminum alloy, and stainless steel can be listed. As the material of the protective resin layer, for example, polyethylene terephthalate (PET) and nylon can be listed. 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. As the thickness of the protective resin layer, 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.

[0070] (2) Electrode body

[0071] 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.

[0072] 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 shape of the positive electrode active material is, for example, a particle shape. As the positive electrode active material, for example, an oxide active material can be cited. In addition, sulfur (S) can be used as the positive electrode active material.

[0073] As the positive electrode active material, preferably a lithium composite oxide is included. The lithium composite oxide may contain at least one selected from F, Cl, N, S, Br and I. In addition, the lithium composite oxide may 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 main arrangement of transition metals, oxygen and lithium in the lithium composite oxide may be an O2 type structure.

[0074] 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 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, and satisfies 0.5≤x≤1.5, 0.5≤y≤1.0, 1≤α<2, 0<β≤1.) A compound represented by.

[0075] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 2(satisfying 1.5≤x1≤2.3, M 1 Contains at least one selected from Ni, Co, Mn, Cu and Fe, A 1 Contains at least oxygen, A 1 The ratio of oxygen in the mixture is 85 atomic % or more. A composite oxide represented by (as a specific example, Li2NiO2) or a composite oxide represented by Li x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0≤x2≤0.5, 0≤y≤0.3, at least one of x2 and y is not 0, M 1A represents at least one selected from Ni, Co, Mn, Cu and Fe, M 1B A represents at least one selected from Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta and W, and A2 represents at least one selected from F, Cl, Br, S and P. ) represents a composite oxide.

[0076] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include: x M2 y A composite oxide represented by O2 (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), and x+y satisfies 0<x+y≤2.).

[0077] Examples of lithium composite oxides having an O2 type structure include Li x [Li α (Mn a Co b M c ) 1-α ]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.) A composite oxide represented by, as a specific example, Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni0.115 ]O2, etc.

[0078] In addition, the positive electrode preferably includes a solid electrolyte selected from the solid electrolyte group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte in addition to the positive electrode active material, and more preferably at least a portion 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 that covers at least a portion 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].

[0079] As the conductive material, for example, carbon materials can be listed. The electrolyte can be a solid electrolyte or a liquid electrolyte. The solid electrolyte can 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. In addition, the liquid electrolyte (electrolyte) contains, for example, a supporting salt such as LiPF6, and a solvent such as a carbonate solvent. In addition, as the adhesive, for example, a rubber adhesive and a fluoride adhesive can be listed.

[0080] 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 negative electrode active materials include metal active materials such as Li and Si; carbon active materials such as graphite; Li4Ti5O 12 The negative electrode current collector may be in the form of a foil or a mesh. The conductive material, electrolyte, and binder are the same as those described above.

[0081] 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. As the electrolyte layer, a solid electrolyte layer is preferred. The electrolyte layer may have a separator (diaphragm).

[0082] As the solid electrolyte, it is preferable to contain at least one solid electrolyte selected from the solid electrolyte group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte.

[0083] As a sulfide solid electrolyte, it is preferred to contain sulfur (S) as the main component of the anion element, and more preferably contain, for example, Li element, A element, and S element. The A element is at least one selected from P, As, Sb, Si, Ge, Sn, B, Al, Ga and In. The sulfide solid electrolyte may further contain at least one of O and a halogen element. As a halogen element (X), for example, F, Cl, Br, I, etc. can be listed. There is no particular limitation on the composition of the sulfide solid electrolyte, for example, xLi2S·(100-x)P2S5(70≤x≤80), yLiI·zLiBr·(100-yz)(xLi2S·(1-x)P2S5)(0.7≤x≤0.8, 0≤y≤30, 0≤z≤30) can be listed. The sulfide solid electrolyte may have a composition represented by the following general formula (1).

[0084] Li 4-x Ge 1-x P x S4(0<x<1)···Formula (1)

[0085] In formula (1), at least a portion of Ge may be replaced by at least one selected from Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V and Nb. In addition, at least a portion of P may be replaced by at least one selected from Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V and Nb. A portion of Li may be replaced by at least one selected from Na, K, Mg, Ca and Zn. A portion of S may be replaced by a halogen. The halogen is at least one selected from F, Cl, Br and I.

[0086] As an oxide solid electrolyte, it is preferred to contain oxygen (O) as the main component of the anion element, 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. As oxide solid electrolytes, garnet-type solid electrolytes, perovskite-type solid electrolytes, NASICON-type solid electrolytes, Li-PO-based solid electrolytes, Li-BO-based solid electrolytes, etc. can be listed. As garnet-type solid electrolytes, for example, Li7La3Zr2O 12 , Li 7-x La3(Zr 2-x Nb x ) 12 (0≤x≤2), Li5La3Nb2O 12Etc. As perovskite-type solid electrolytes, for example, (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, etc. can be listed. As NASICON-type solid electrolytes, for example, Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, etc. can be listed. As Li-PO-based solid electrolytes, Li3PO4 and LIPON (compounds in which a part of O of Li3PO4 is replaced by N) can be listed. As Li-BO-based solid electrolytes, Li3BO3 and compounds in which a part of O of Li3BO3 is replaced by C can be listed.

[0087] As the halide solid electrolyte, a solid electrolyte containing Li, M and X is preferred (M represents at least one of Ti, Al and Y, and X represents F, Cl or Br). Specifically, Li 6-3z Y z X6 (X represents Cl or Br, z satisfies 0<z<2.), Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0<x<1, 0<b≤1.5). 6-3z Y z Among X6, Li3YX6 (X represents Cl or Br) is more preferred from the viewpoint of excellent lithium ion conductivity, and Li3YCl6 is further preferred. In addition, for example, from the viewpoint of suppressing oxidative decomposition of sulfide solid electrolytes, it is preferred to contain Li3YX6 together with solid electrolytes such as sulfide solid electrolytes. 6-(4-x)b (Ti 1-x Al x ) b F6 (0<x<1, 0<b≤1.5).

[0088] 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-shaped or mesh-shaped.

[0089] 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.

[0090] Battery structure

[0091] The structure of a solid battery has a stacked structure of positive electrode / solid electrolyte layer / negative electrode. Solid batteries include so-called all-solid batteries using a solid electrolyte as an electrolyte, and the solid electrolyte may contain less than 10% by mass of an electrolyte relative to the total amount of the electrolyte. Furthermore, the solid electrolyte may be a composite solid electrolyte comprising an inorganic solid electrolyte and a polymer electrolyte.

[0092] 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.

[0093] The solid electrolyte layer may have a single-layer structure or a multi-layer structure of two or more layers.

[0094] Solid state batteries may have, for example, Figure 6 The cross-sectional structure shown in Figure 6 As shown, the solid electrolyte layer B may be a two-layer structure. Figure 6 This is a schematic cross-sectional view showing an example of a solid battery.

[0095] Figure 6 The solid battery shown has a negative electrode including a negative electrode collector 113 and a negative electrode active material layer A, a solid electrolyte layer B, and a positive electrode including a positive electrode 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 auxiliary agent 105, and a binder 109. The positive electrode active material layer C includes a coated positive electrode active material 103, a conductive auxiliary agent 107, and a binder 111, and the surface of the positive electrode active material coated with the positive electrode active material 103 is coated with an LTAF electrolyte or a LiNbO3 electrolyte.

[0096] In addition, the solid battery can be formed by sealing the stacked end faces (side faces) of the stacked structure of the positive electrode / solid electrolyte layer / negative electrode with resin. The current collector of the electrode can be configured with a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer on the surface.

[0097] ·Battery

[0098] The laminated battery in the present disclosure is typically a lithium ion secondary battery. As the purpose of the battery, for example, the power supply of vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles can be listed. It is particularly preferably used as a driving power supply for hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) or electric vehicles (BEV). In addition, the battery of the present disclosure can be used as a power supply for mobile bodies (such as railways, ships, and aircraft) other than vehicles, and can also be used as a power supply for electrical products such as information processing devices.

[0099] The present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are illustrative only, and any technical solution having substantially the same configuration and having the same function and effect as the technical concept described in the patent 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 laminated film covering and sealing the electrode body. The laminated film has a welded portion where the ends overlap each other and the inner surfaces are welded, The weld portion includes an acute angle bent portion bent into an angle or arc shape at an angle less than 90°, and a distal end side region extending in a direction opposite to a bending direction of the acute angle bent portion in a region located on a distal end side of the weld portion relative to the acute angle bent portion.

2. The stacked battery according to claim 1, wherein: The angle of the acute-angle bent portion is greater than or equal to 30° and less than or equal to 75°.

3. 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 welded portion in which the ends overlap each other and the inner surface is welded, The manufacturing method comprises a bending step, wherein: The rotating disk-shaped fulcrum roller member is brought into contact with the welded portion, and the welded portion is bent at an angle less than 90 degrees with the portion where the fulcrum roller member is brought into contact as a fulcrum to form an acute angle bent portion. The fulcrum roller member has a protrusion arranged in the circumferential direction at an outer peripheral end portion of the disk-like shape on a surface on a side in contact with the welded portion.

4. The method for manufacturing a stacked battery according to claim 3, wherein: In the bending step, the weld portion is bent while being brought into contact with an elastic roller from a side opposite to a side where the projection of the fulcrum roller member contacts a portion of the weld portion where the acute-angle bent portion is formed.

5. The method for manufacturing a stacked battery according to claim 3 or 4, wherein: The angle of the tip of the protrusion is greater than or equal to 20° and less than or equal to 45°.

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