Laminated battery and method for manufacturing laminated battery

Abstract

To provide a laminated battery in which the fused portion has superior impact resistance to impacts from the outside.SOLUTION: A laminate type battery 10A includes: an electrode body 2; and a laminate film 4 that covers and seals the electrode body 2 inside. The laminate film 4 includes a fused part 40 formed by superposing end portions of the laminate film and fusing together their inner surfaces. The fused part 40 includes three or more bend parts including two or more fold parts 40a and 40b that are bent in a rectangular shape or an arc shape so as to have an angle of 90° or less, and one tip end-side bend part 40c that is bent in the rectangular shape or the arc shape so as to have an angle that is less than 180° at a position closest to a tip end 400 of the fused part 40. The fused part 40 has a shape in which at least part of the tip end 400 is directed toward the electrode body 2 side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

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

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

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

[0005] In a laminated battery in which the electrode body is covered with a single laminate film, one end of the laminate film is overlapped with the other end and their inner surfaces are fused to form a fused portion, thereby encapsulating the electrode body with the laminate film. In a laminated battery in which the electrode body is covered with multiple laminate films, the ends of multiple laminate films are overlapped with each other and their inner surfaces are fused to form a fused portion, thereby encapsulating the electrode body. To improve the structural efficiency of a laminated battery, these fused portions are, for example, folded to reduce the overall external size of the laminated battery.

[0006] If an impact is applied to the electrode body included in a laminated battery, the electrode body may be damaged, and the battery may not be able to exhibit the required performance. Therefore, laminated batteries are required to have high impact resistance, and the fused portions of the laminate film are also required to have high impact resistance against external impacts.

[0007] The present disclosure has been made in view of the above-described circumstances, and aims to provide a laminated battery having excellent impact resistance at fused portions against external impacts, and a method for manufacturing such a laminated battery. [Means for solving the problem]

[0008] <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 three or more bent portions, including two or more bent portions bent in an angular or arc shape at an angle of 90° or less, and one tip-side bent portion bent in an angular or arc shape at an angle of less than 180° at a position closest to the tip of the fused portion, The fused portion has a shape in which at least a part of the tip faces the electrode body side. <2> The bent portion and the tip-side bent portion are both bent in an arc shape. <1> 2. The laminated battery according to claim 1. <3> The position where the tip side bent portion is arranged is the position closest to the base side bent portion of the fused portion among the two or more bent portions. <1> or <2> 2. The laminated battery according to claim 1. <4> The fused portion has, as the bent portion, one or more right-angle bent portions bent in an angular or arc shape at an angle of 70° or more and 90° or less, and one folded-back bent portion bent in an angular or arc shape at an angle of 20° or less. <1> ~ <3> 10. The laminated battery according to claim 9, wherein the first and second electrodes are electrically connected to each other. <5> The shortest distance between the tip of the fused portion and the laminate film in the area covering the electrode body is 0.5 mm or more and 5 mm or less. <1> ~ <4> 10. The laminated battery according to claim 9, wherein the first and second electrodes are electrically connected to each other. <6> <5> A method for manufacturing the laminated battery according to claim 1, preparing a fused laminated battery having a planar fused portion in which the ends of the laminate film are overlapped and the inner surfaces are fused; a folding-back process for forming a folded-back portion in the fused portion of the laminate-type battery, the folded-back portion being bent in an angular or arc shape at an angle of 20° or less; a right-angle bending process for forming a right-angle bent portion bent in an angular or arc shape at an angle of 70° to 90° in a region closer to the root of the fused portion than the folded-back bent portion; and the right-angle bending step is a step of bending the fused portion in stages by conveying the sheet between roller pairs of a group of roller pairs, the group including at least three bending rollers that contact the surface of the fused portion on the bending side and have different contact angles with the fused portion, and the same number of opposing rollers as the bending rollers that are provided at positions opposing the folding rollers across the fused portion, to form the right-angle bent portion; and the right-angle bending process is a process of contacting an area of ​​the fused portion that is closer to the tip than the folded-back bent portion with at least one bending roller in the roller pair group to form the tip-side bent portion. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a laminated battery in which the fused portion has excellent impact resistance against external impacts, and a method for manufacturing such a laminated battery. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view illustrating a laminated battery according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating a laminated battery according to another aspect of the present embodiment. [Figure 3] FIG. 2 is a schematic cross-sectional view illustrating a laminated battery according to another aspect of the present embodiment. [Figure 4] FIG. 2 is a schematic cross-sectional view illustrating a laminated battery according to another aspect of the present embodiment. [Figure 5] FIG. 1 is a schematic cross-sectional view showing an example of a solid-state battery. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Laminated battery> A laminated battery according to an embodiment of the present disclosure comprises an electrode body and a laminate film that covers the electrode body and encloses it inside, the laminate film having a fused portion where the ends are overlapped and the inner surface is fused, the fused portion having three or more bent portions including two or more bent portions bent into an angular or arc shape at an angle of 90° or less, and one tip-side bent portion bent into an angular or arc shape at an angle of less than 180° at a position closest to the tip of the fused portion, and at least a portion of the tip of the fused portion is shaped so that at least a portion of the tip faces the electrode body.

[0012] Because at least a portion of the tip of the fused part faces the electrode body, even if an external impact is applied to the fused part, the tip first hits the electrode body (the laminate film covering the electrode body) and is absorbed, making the fused part less likely to deform even if further external impact is applied to the fused part. This improves the impact resistance of the fused part, thereby reducing damage to the electrode body.

[0013] 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.

[0014] (First aspect) FIG. 1 is a schematic cross-sectional view illustrating a laminated battery according to this embodiment. The laminated battery 10A has 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 40 where one end and the other end are overlapped and the inner surfaces are fused together. The electrode assembly 2 has a shape in which the end surface 20 (the end surface on which the fused portion 40 is formed shown in FIG. 1) is an inclined surface. The fused portion 40 is formed on the inclined end surface 20 of the electrode assembly 2 from the end portion that protrudes further outward (the lower end portion of the end surface 20 in FIG. 1) toward the outside. The fused portion 40 has three bent portions in total, from the base side of the fused portion 40 (i.e., the position closest to the electrode body 2) to the tip 400 side: a right-angle bent portion 40a bent in an arc at an angle of approximately 90°, a folded-back bent portion 40b bent in an arc at an angle of approximately 0°, and a tip-side bent portion 40c bent in an arc at an angle of approximately 90° at the position of the fused portion 40 closest to the tip 400. Of all the remaining bent portions (i.e., the right-angle bent portion 40a and the folded-back bent portion 40b), the tip-side bent portion 40c is located in a position closest to the right-angle bent portion 40a, which corresponds to the bent portion closest to the base side of the fused portion 40. Here, the angle of the fused portion in this disclosure refers to the smallest angle formed by the fused portions on both sides of the bent portion.

[0015] The fused part 40 has a shape in which the tip 400 faces the electrode body 2. The fused part 40 shown in Fig. 1 has a shape in which the entire area of ​​the tip 400 faces the electrode body 2 in the longitudinal direction of the fused part 40 (the depth direction in Fig. 1). Here, having a shape in which the tip faces the electrode body side means that the tip of the fused portion is located closer to the electrode body than the tip-side bent portion.

[0016] As such, the laminated battery 10A shown in FIG. 1 has a shape in which the leading edge 400 faces the electrode assembly 2. Assume that an external impact is applied to the fused portion 40, for example, from the right side in FIG. 1. In this case, the fused portion 40 deforms starting from the right-angle bent portion 40a, and the leading edge 400 first hits and is received by the electrode assembly 2 (the laminate film 4 covering the electrode assembly 2). Even if further external impacts are subsequently applied to the fused portion 40 (for example, from the right side in FIG. 1), the fused portion 40 is less likely to deform because the leading edge 400 is in contact with the electrode assembly 2. This improves the impact resistance of the fused portion 40, thereby preventing damage to the electrode assembly 2 due to impacts applied to the fused portion 40.

[0017] Although FIG. 1 shows an embodiment in which three curved portions are bent in an arc shape, the curved portions may be bent in an angular shape, that is, in a shape having corners.

[0018] 1 shows an embodiment in which the entire region of the tip 400 in the longitudinal direction of the fused portion 40 has a shape facing the electrode body 2, but it is sufficient if at least a portion of the tip of the fused portion has a shape facing the electrode body. By having at least a portion of the tip of the fused portion facing the electrode body, even if an external impact is applied to the fused portion, the portion of the tip facing the electrode body first hits and receives the impact, improving the impact resistance of the fused portion and suppressing damage to the electrode body.

[0019] Note that a laminated battery according to an embodiment of the present disclosure may have three or more bent portions, including two or more bent portions in the fused portion that are bent into an angular or arc shape at an angle of 90° or less, and one tip-side bent portion in the fused portion that is bent into an angular or arc shape at an angle of less than 180° at a position closest to the tip. From the viewpoint of improving the structural efficiency of the fused portion, it is preferable that the fused portion have one or more right-angle bent portions that are bent into an angular or arc shape at an angle of 70° to 90°, and one folded-back bent portion that is bent into an angular or arc shape at an angle of 20° or less.

[0020] (Second aspect) FIG. 2 is a schematic cross-sectional view illustrating a laminated battery according to another aspect of the present embodiment. The laminated battery 10B 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 42 where one end and the other end are overlapped and the inner surfaces are fused together. The fused portion 42 has five bent portions extending from the base side of the fused portion 42 (i.e., the position closest to the electrode assembly 2) to the tip 420 side: a right-angle bent portion 42a bent into an arc at an angle of approximately 90°, a right-angle bent portion 42b bent into an arc at an angle of approximately 90°, a folded-back bent portion 42c bent into an arc at an angle of approximately 0°, a right-angle bent portion 42d bent into an arc at an angle of approximately 90°, and a tip-side bent portion 42e bent into an arc at an angle of approximately 90° at the position closest to the tip 420 of the fused portion 42. The tip-side bend 42e is located at the position closest to the right-angle bend 40a, which corresponds to the bend closest to the base of the fused portion 42, among all the remaining bends (i.e., the right-angle bends 40a, 40b, 40d, and the folded bend 40c).

[0021] The fused portion 42 has a shape in which the tip 420 faces the electrode body 2. In other words, the tip 420 of the fused portion 42 is located closer to the electrode body 2 than the tip-side bent portion 42e. The fused portion 42 shown in Fig. 2 has a shape in which the entire area of ​​the tip 420 faces the electrode body 2 in the longitudinal direction of the fused portion 42 (the depth direction in Fig. 2).

[0022] Thus, the laminated battery 10B shown in FIG. 2 has a shape in which the leading edge 420 faces the electrode body 2. Assume that an external impact is applied to the fused portion 42, for example, from the right side in FIG. 2. In this case, the fused portion 42 deforms starting from the right-angle bent portion 42a, and the folded-back bent portion 42c first comes into contact with the electrode body 2 (the laminate film 4 covering the electrode body 2). However, as the impact continues to be applied, it is believed that the folded-back bent portion 42c that has come into contact with the electrode body 2 will slip and shift (shift upward in FIG. 2). If further impacts are subsequently applied to the fused portion 42, the leading edge 420 will then come into contact with the electrode body 2 (the laminate film 4 covering the electrode body 2) and be received. After that, even if further impacts are applied to fused portion 42 from the outside (for example, from the right side in FIG. 2), fused portion 42 is less likely to deform because tip portion 420 is in contact with electrode body 2. This improves the impact resistance of fused portion 42, and as a result, it is possible to prevent damage to electrode body 2 due to impacts applied to fused portion 42.

[0023] Although FIG. 2 shows an embodiment in which there are five curved portions bent in an arc shape, the curved portions may be bent in an angular shape, that is, in a shape having corners. Furthermore, Figure 2 shows an embodiment in which the entire area of ​​the tip 420 in the longitudinal direction of the fused portion 42 has a shape facing the electrode body 2, but it is sufficient if at least a portion of the tip of the fused portion has a shape facing the electrode body.

[0024] (Third aspect) FIG. 3 is a schematic cross-sectional view illustrating a laminated battery according to another aspect of the present embodiment. The laminated battery 10C 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 44 where one end and the other end are overlapped and the inner surfaces are fused together. The fused portion 44 has three bent portions extending from the base side of the fused portion 44 (i.e., the position closest to the electrode assembly 2) toward the tip 440: a right-angle bent portion 44a that is bent in an arc at an angle of approximately 90°, a folded-back bent portion 44b that is bent in an arc at an angle of approximately 0°, and a tip-side bent portion 44c that is bent in an arc at an angle of approximately 90° at the position closest to the tip 440 of the fused portion 44. Furthermore, the tip-side bent portion 44c is positioned closest to the bent portion 44b, which does not correspond to the base-most bent portion of the fused portion 44, among all the remaining bent portions (i.e., the right-angle bent portion 44a and the bent portion 44b).

[0025] The fused portion 44 has a shape in which the tip 440 faces the electrode body 2. In other words, the tip 440 of the fused portion 44 is located closer to the electrode body 2 than the tip-side bent portion 44e. The fused portion 44 shown in Figure 3 has a shape in which the entire area of ​​the tip 440 faces the electrode body 2 in the longitudinal direction of the fused portion 44 (the depth direction in Figure 3).

[0026] Thus, the laminated battery 10C shown in FIG. 3 has a shape in which the leading end 440 faces the electrode assembly 2. Assume that an external impact is applied to the fused portion 44, for example, from the right side in FIG. 3. In this case, the fused portion 44 deforms starting from the right-angle bent portion 44a, and the leading end 440 first hits and is received by the electrode assembly 2 (the laminate film 4 covering the electrode assembly 2). Even if further external impacts are subsequently applied to the fused portion 44 (for example, from the right side in FIG. 3), the fused portion 44 is less likely to deform because the leading end 440 is in contact with the electrode assembly 2. This improves the impact resistance of the fused portion 44, thereby preventing damage to the electrode assembly 2 due to impacts applied to the fused portion 44.

[0027] Although FIG. 3 shows an embodiment in which three curved portions are bent in an arc shape, the curved portions may be bent in an angular shape, that is, in a shape having corners. Furthermore, Figure 3 shows an embodiment in which the entire area of ​​the tip 440 in the longitudinal direction of the fused portion 44 has a shape facing the electrode body 2, but it is sufficient if at least a portion of the tip of the fused portion has a shape facing the electrode body.

[0028] 1 to 3 show the electrode body having an inclined end face, the shape of the electrode body is not limited to this. For example, as shown in Fig. 4, an electrode body 2D having a rectangular parallelepiped shape can also be used.

[0029] In the laminated battery according to the embodiment of the present disclosure, the tip of the fused portion faces the electrode assembly. The shortest distance between the tip of the fused portion and the laminate film covering the electrode assembly is preferably 0.5 mm to 5 mm, more preferably 0.5 mm to 1 mm, from the viewpoint of improving the impact resistance of the fused portion against external impacts. The shortest distance between the tip of the fused portion and the laminate film covering the electrode assembly is, for example, distance a1 in FIG. 1 , distance a2 in FIG. 2 , distance a3 in FIG. 3 , and distance a4 in FIG. 4 .

[0030] 1 to 3 show a laminated battery in which the electrode body is covered with a single laminate film. However, the present disclosure is not limited to this, and a laminated battery in which the electrode body is covered with multiple laminate films may also be used. For example, a laminated battery in which the electrode body is covered with two laminate films may be used, in which the edges of the two laminate films are overlapped and fused together at their inner surfaces to form a fused portion, thereby encapsulating the battery.

[0031] <Laminated battery manufacturing method> Next, a method for manufacturing a laminated battery according to an embodiment of the present disclosure will be described. The method for manufacturing a laminated battery includes an electrode body and a laminate film that covers and encloses the electrode body, the laminate film having a fused portion where the ends are overlapped and the inner surfaces are fused together, the fused portion having three or more bent portions, including two or more folded portions bent into an angular or arc shape at an angle of 90° or less, and one tip-side bent portion bent into an angular or arc shape at an angle of less than 180° at a position closest to the tip of the fused portion, the fused portion having a shape with at least a portion of its tip facing the electrode body, and the fused portion having, as a bent portion, one folded-back bent portion bent into an angular or arc shape at an angle of 20° or less, and one or more right-angle bent portions formed closer to the base of the fused portion than the folded-back bent portion and bent into an angular or arc shape at an angle of 70° to 90°.

[0032] and preparing a fused laminated battery having a planar fused portion in which the ends of the laminate films are overlapped and the inner surfaces are fused together. a folding-back process for forming a folded-back portion in the fused portion of the laminated battery, the folded-back portion being bent in an angular or arc shape at an angle of 20° or less; a right-angle bending process for forming a right-angle bent portion bent in an angular or arc shape at an angle of 70° to 90° in a region closer to the root of the fused portion than the folded-back bent portion; and The right-angle bending step is a step of bending the fused portion in stages to form a right-angle bent portion by conveying the sheet between roller pairs of a group of roller pairs, the group including at least three folding rollers that contact the bent side surface of the fused portion and have different contact angles with respect to the fused portion, and the same number of opposing rollers as the folding rollers that are provided at positions opposing the folding rollers across the fused portion, The right-angle bending step is a step of bringing an area of ​​the fused portion closer to the tip than the folded-back bent portion into contact with at least one bending roller in the roller pair group, thereby forming a tip-side bent portion.

[0033] Example of manufacturing the laminated battery of the first embodiment First, a method for manufacturing the laminated battery of the first embodiment shown in Fig. 1 will be described. The right-angle bent portion 40a, the folded-back bent portion 40b, and the tip-side bent portion 40c in the laminated battery 10A of the first embodiment can be formed, for example, by carrying out the folding-back bending process and the right-angle bending process described below.

[0034] First, a laminated battery (a fused laminated battery) having an unfolded, planar fused portion 40 is folded to form folded portion 40b (folding step). The folding operation in the folding step can be performed, for example, by conveying the battery between pairs of rollers in a group of roller pairs, which includes a plurality of folding rollers that contact the folded side of fused portion 40 (i.e., the valley fold side of folded portion 40b) and have different contact angles with fused portion 40, and the same number of opposing rollers as the folding rollers that are positioned opposite the folding rollers across fused portion 40, thereby folding fused portion 40 in stages.

[0035] Next, a bending operation is performed on the fused portion 40 having the folded-back bent portion 40b formed therein, in a region closer to the base of the fused portion 40 than the folded-back bent portion 40b, to form a right-angle bent portion 40a (right-angle bending step). The bending operation in the right-angle bending step may be performed, for example, by conveying the fused portion 40 between pairs of rollers in a group of pairs of rollers, the group having at least three folding rollers that contact the surface of the folding side of the fused portion 40 (i.e., the valley fold side of the right-angle bent portion 40a) and have different contact angles with the fused portion 40, and the same number of opposing rollers as the folding rollers that are provided in positions opposing the folding rollers across the fused portion 40, thereby folding the fused portion 40 in stages.

[0036] In the right-angle bending step, a tip-side bent portion 40c can be formed by contacting at least one bending roller in the group of roller pairs with a region of the fused portion 40 closer to the tip 400 than the folded-back bent portion 40b. When at least one bending roller in the group of roller pairs is contacted with the region of the fused portion 40 closer to the tip 400, the roller may contact the entire region of the tip 400 in the longitudinal direction of the fused portion 40, or may contact only a part of the tip 400 of the fused portion 40.

[0037] In the right-angle bending step, the right-angle bent portion 40a is formed using the above-mentioned roller pair group having at least three bending rollers with different contact angles, and at least one bending roller in the above-mentioned roller pair group is brought into contact with a region on the tip 400 side of the fused portion 40 to form the tip-side bent portion 40c, thereby suppressing the occurrence of springback in the fused portion 40. Furthermore, at least a portion of the tip 400 of the fused portion 40 can be shaped to face the electrode body 2 side, thereby improving the impact resistance of the fused portion 40.

[0038] Example of manufacturing a laminated battery according to the second embodiment A method for manufacturing the laminated battery of the second embodiment shown in FIG. 2 may be a method in which, in the manufacturing example of the laminated battery of the first embodiment described above, a second right-angle bending step is further performed after the folding step and before the right-angle bending step, or after the right-angle bending step.

[0039] That is, the folded portion 42c is formed in the same manner as in the laminated battery manufacturing example of the first embodiment (folding step), and then the right-angle bent portion 42a and the leading-end bent portion 42e are formed in the same manner as in the laminated battery manufacturing example of the first embodiment (right-angle bending step). Then, right-angle bent portions 42b and 42d are formed in the region between the folded portion 42c and the leading-end bent portion 42e, and in the region between the folded portion 42c and the right-angle bent portion 42a, respectively (second right-angle bending step). The folding operation in the second right-angle bending step can be performed, for example, by conveying the sheet between pairs of rollers in a group of roller pairs, which includes multiple folding rollers that contact the folding side of the fused portion 42 (i.e., the valley fold side of the right-angle bent portion 42d) and have different contact angles with the fused portion 42, and an equal number of opposing rollers that are positioned opposite the folding rollers across the fused portion 42, thereby folding the fused portion 42 in stages. The second right-angle bending step may be performed after the back bending step and before the right-angle bending step.

[0040] According to the manufacturing example of the laminated battery of the second embodiment described above, it is possible to suppress the occurrence of springback in the fused portion 42. Furthermore, at least a part of the tip 420 of the fused portion 42 can be shaped to face the electrode body 2, thereby improving the impact resistance of the fused portion 42.

[0041] The method for manufacturing the laminated battery according to the embodiment of the present disclosure is not limited to the above-described method. For example, a method for manufacturing the laminated battery according to the third embodiment shown in Fig. 3 may include forming the right-angle bent portion 44a, the folded-back bent portion 44b, and the tip-side bent portion 44c in separate bending steps.

[0042] (Battery components) Next, the electrode body and laminate film that constitute the laminate battery according to this embodiment will be described.

[0043] (1) Laminate film Examples of laminate films include films having a metal layer, and films with a three-layer structure having a resin layer on each side of the metal layer. In the three-layer structure film, the inner resin layer on the electrode body side (i.e., the resin layer that fuses) is the fusion resin layer, and the resin layer on the outer peripheral surface side opposite the electrode body side is the protective resin layer.

[0044] 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.

[0045] (2) Electrode body The electrode body functions as a power generating element of the battery. The shape of the electrode body is not particularly limited, but examples thereof include a rectangular parallelepiped shape and a shape with inclined end faces. The electrode body 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, arranged in this order in the thickness direction.

[0046] 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.

[0047] 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.

[0048] 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.)

[0049] 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 oxygen ratio 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, and M 1Arepresents 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.). Examples thereof include composite oxides represented by

[0050] Examples of the lithium composite oxide having a crystal structure belonging to P63 - mmc include, for example, M1 x M2 y O2 (where M1 represents an alkali metal (at least one of Na and K is preferred), M2 represents a transition metal (at least one selected from the group consisting of Mn, Ni, Co, and Fe is preferred), and 0 < x + y ≦ 2 is satisfied). Examples thereof include composite oxides represented by

[0051] Examples of the lithium composite oxide having an O2-type structure include, for example, 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, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi). Specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 and the like.

[0052] In addition, the positive electrode preferably contains a solid electrolyte selected from the group of solid electrolytes consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte, 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 that coats 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.

[0053] Examples of the conductive material include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Further, the liquid electrolyte (electrolyte solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. Examples of the binder include rubber-based binders and fluoride-based binders.

[0054] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and oxide active materials such as Li4Ti5O 12 and the like. The shape of the negative electrode current collector is, for example, foil-shaped or mesh-shaped. The conductive material, electrolyte, and binder are the same as those described above.

[0055] 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.

[0056] Preferably, the solid electrolyte contains at least one solid electrolyte species selected from the group of solid electrolytes consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes.

[0057] As the 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.

[0058] As the oxide solid electrolyte, it is preferable 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. 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(Zr 2-x Nb x )O 12 (0 ≦ x ≦ 2), Li5La3Nb2O 12 and the like. Examples of the perovskite-type solid electrolyte include, for example, (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, etc. Examples of the NASICON-type solid electrolyte include, for example, Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, etc. Examples of the Li-P-O-based solid electrolyte include Li3PO4, LIPON (a compound in which a part of O in Li3PO4 is replaced by N), and examples of the Li-B-O-based solid electrolyte include Li3BO3, a compound in which a part of O in Li3BO3 is replaced by C, etc.

[0059] As the 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 preferable. Among Li 6-3z Y z X6, Li3YX6 (X represents Cl or Br) is more preferable in terms of excellent lithium ion conductivity, and further Li3YCl6 is preferable. Also, Li 6-(4-x)b (Ti 1-x Al x ) bF6 (0 < x < 1, 0 < b ≤ 1.5) is preferably included together with a solid electrolyte such as a sulfide solid electrolyte from the viewpoint of, for example, suppressing the oxidative decomposition of the sulfide solid electrolyte.

[0060] The positive electrode current collector conducts the current collection of the positive electrode active material layer. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, iron, titanium, carbon, etc., and an aluminum alloy foil or an aluminum foil is preferable. The aluminum alloy foil and the aluminum foil may be manufactured using powder. The shape of the positive electrode current collector is, for example, foil-shaped or mesh-shaped.

[0061] The negative electrode current collector conducts the current collection of the negative electrode active material layer. Examples of the material of the negative electrode current collector include metals such as copper, SUS, nickel, etc. Examples of the shape of the negative electrode current collector include foil-shaped and mesh-shaped.

[0062] · Battery structure The structure of the solid battery has a laminated structure of a positive electrode / solid electrolyte layer / negative electrode. The solid battery includes a so-called all-solid battery using a solid electrolyte as the electrolyte, and the solid electrolyte may contain an electrolytic solution of less than 10% by mass with respect to the total amount of the electrolyte. Note that the solid electrolyte may be a composite solid electrolyte containing an inorganic solid electrolyte and a polymer electrolyte.

[0063] 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. 5, and the solid electrolyte layer B may have a two-layer structure as shown in FIG. 5. FIG. 5 is a schematic cross-sectional view showing an example of a solid-state battery. The solid-state battery shown in FIG. 5 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.

[0064] ·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.

[0065] 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]

[0066] 2 Electrode body 4. Laminating film 10A, 10B, 10C laminated batteries 20 End face 40a, 42a, 42b, 42d, 44a Right-angle bends 40b, 42c, 44b Folded section 40c, 42e, 44c Tip bend 400, 420, 440 tip 101 Negative electrode active material 103 Coated cathode active material 105, 107 Conductive additives 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 three or more bent portions, including two or more bent portions bent in an angular or arc shape at an angle of 90° or less, and one tip-side bent portion bent in an angular or arc shape at an angle of less than 180° at a position closest to the tip of the fused portion, The fused portion has a shape in which at least a part of a tip thereof faces the electrode body side, A laminated battery, wherein the shortest distance between the tip of the fused portion and the laminate film in the area covering the electrode body is 0.5 mm or more and 5 mm or less.

2. 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 three or more bent portions, including two or more bent portions bent in an angular or arc shape at an angle of 90° or less, and one tip-side bent portion bent in an angular or arc shape at an angle of less than 180° at a position closest to the tip of the fused portion, The fused portion has a shape in which at least a part of a tip thereof faces the electrode body side, A laminated battery, wherein the position where the tip-side bent portion is arranged is the position of the two or more bent portions that is closest to the bent portion closest to the base side of the fused portion.

3. 3. The laminated battery according to claim 1, wherein the bent portion and the tip-side bent portion are both bent in an arc shape.

4. 3. The laminated battery according to claim 1, wherein the fused portion has, as the bent portion, one folded portion bent in an angular or arc shape at an angle of 20° or less, and one or more right-angle bent portions formed closer to the base of the fused portion than the folded portion and bent in an angular or arc shape at an angle of 70° or more and 90° or less.

5. 5. A method for manufacturing a laminated battery according to claim 4, preparing a fused laminated battery having a planar fused portion in which the ends of the laminate film are overlapped and the inner surfaces are fused; a folding-back process of forming a folded-back portion in the fused portion of the laminate-type battery, the folded-back portion being bent in an angular or arc shape at an angle of 20° or less; a right-angle bending process for forming a right-angle bent portion bent in an angular or arc shape at an angle of 70° to 90° in a region closer to the root of the fused portion than the folded-back bent portion; and the right-angle bending step is a step of bending the fused portion in stages by conveying the sheet between roller pairs of a group of roller pairs, the group including at least three folding rollers that contact the surface of the fused portion on the folding side and have different contact angles with the fused portion, and opposing rollers, the number of which is the same as the folding rollers, that are provided at positions opposing the folding rollers across the fused portion, to form the right-angle bent portion; and the right-angle bending process is a process of contacting an area of ​​the fused portion that is closer to the tip than the folded-back bent portion with at least one bending roller in the roller pair group to form the tip-side bent portion.

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