Laminated battery, and method for manufacturing a laminated battery

Abstract

To provide a laminate-type battery with excellent impact resistance of the fused joint against external shocks. [Solution] A laminate-type battery 10A comprising an electrode body 2 and a laminate film 4 that covers the electrode body 2 and seals it inside, wherein the laminate film 4 has a fused portion 40 where the ends are overlapped and the inner surface is fused together, and the fused portion 40 has three or more bent portions, including two or more bent portions 40a, 40b that are bent in an angular or arc shape at an angle of 90° or less, and one tip-side bent portion 40c that is bent in an angular or arc shape at an angle of less than 180° at the position closest to the tip 400 of the fused portion 40, and the fused portion 40 has a shape in which at least a part of the tip 400 faces toward the electrode body 2.

Description

[Technical Field]

[0001] This disclosure relates to laminated batteries and methods for manufacturing laminated batteries. [Background technology]

[0002] In laminate-type batteries, where the electrode body is covered with a laminate film, a portion of the laminate film is fused to form a fused section in order to enclose the electrode body.

[0003] For example, Patent Document 1 discloses a method for manufacturing a secondary battery having a laminated outer casing with a bent portion at at least one end, comprising the steps of: contacting a pressing plate with the base point of the bend at the end of the outer casing; and, after the contact step, sliding the pressing plate and a pressing plate positioned opposite the pressing plate so as to sandwich the end, thereby bending the end around the base point and forming a bent portion by sandwiching the end between the pressing plate and the pressing plate, wherein the surface of the pressing plate that slides with the end has an inclined surface for bending the end and a clamping surface for sandwiching the end, and the inclined surface is inclined in a cross section perpendicular to the width direction of the pressing plate such that the cross-sectional area of ​​the pressing plate narrows in the sliding direction, and the inclined surface is inclined in the width direction. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-200973 [Overview of the project] [Problems that the invention aims to solve]

[0005] In a laminated battery in which an electrode body is covered with a single laminated film, the electrode body is enclosed with the laminated film by overlapping one end side and the other end side of the laminated film and fusing their inner surfaces to form a fused portion. Further, in a laminated battery in which the electrode body is covered with a plurality of laminated films, the enclosure is performed by overlapping the ends of the plurality of laminated films and fusing their inner surfaces to form a fused portion. In order to improve the structural efficiency of the laminated battery, these fused portions are, for example, bent to reduce the size of the outer shape of the entire laminated battery.

[0006] Here, when an impact is applied to the electrode body included in the laminated battery, the electrode body may be damaged and the required battery performance may not be exhibited. Therefore, the laminated battery is required to have impact resistance, and also at the fused portion of the laminated film, it is required to enhance the impact resistance against an impact applied from the outside.

[0007] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a laminated battery excellent in impact resistance of a fused portion against an external impact and a method for manufacturing the laminated battery.

Means for Solving the Problems

[0008] <1> An electrode body, A laminated film that covers the electrode body and encloses it inside, having, The laminated film has a fused portion where the ends are overlapped and the inner surfaces are fused, The fused portion includes two or more bent portions bent in an angular or arc shape so as to have an angle of 90° or less, and one tip-side bent portion bent in an angular or arc shape so as to have an angle of less than 180° at a position from the most tip of the fused portion, and has three or more bent portions, The laminated battery, wherein at least a part of the tip of the fused portion has a shape facing the electrode body side. <2> Both the bent portion and the bent tip portion are bent in an arc shape. <1> Laminated battery as described above. <3> The position where the tip-side bent portion is located is the position closest to the root-side bent portion among the two or more bent portions. <1> or <2> Laminated battery as described above. <4> The fused portion has, as the bent portion, one or more right-angle bends that are bent in an angular or arc shape at an angle of 70° or more and 90° or less, and one folded-back bend that is bent in an angular or arc shape at an angle of 20° or less. <1> ~ <3> A laminated battery as described in any one of the items. <5> The shortest distance between the tip of the fusion portion and the laminate film covering the electrode body is 0.5 mm or more and 5 mm or less. <1> ~ <4> A laminated battery as described in any one of the items. <6> <5> A method for manufacturing a laminated battery as described above, A process for preparing a post-fusion laminated battery having a planar fused portion in which the edges of laminate films are overlapped and their inner surfaces are fused, A folding and bending step is performed to form a folded and bent portion in the fused portion of the fused laminate-type battery, which is bent in an angular or arc shape at an angle of 20° or less. A right-angle bending step is performed to form a right-angle bend in the region of the fused portion closer to the root than the folded-back bend portion, which is bent in an angular or arc shape at an angle of 70° or more and 90° or less. It has, The right-angle bending process is a process of forming the right-angle bend by conveying the fused portion between each pair of rollers in a group of roller pairs, each roller having at least three bending 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 bending rollers that are positioned opposite the bending rollers via the fused portion. A method for manufacturing a laminate-type battery, wherein the right-angle bending step is a step of bringing the region of the fused portion closer to the tip than the folded-back bending portion into contact with at least one bending roller in the group of rollers, thereby forming the tip-side bending portion. [Effects of the Invention]

[0009] This disclosure provides a laminate-type battery with excellent impact resistance of the fused portion against external impacts, and a method for manufacturing the laminate-type battery. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view illustrating a laminate-type battery according to this embodiment. [Figure 2] This is a schematic cross-sectional view illustrating a laminate-type battery according to another embodiment of this model. [Figure 3] This is a schematic cross-sectional view illustrating a laminate-type battery according to another embodiment of this model. [Figure 4] This is a schematic cross-sectional view illustrating a laminate-type battery according to another embodiment of this model. [Figure 5] This is a schematic cross-sectional view showing an example of a solid-state battery. [Modes for carrying out the invention]

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

[0012] Because at least a portion of the tip of the fused portion faces the electrode body, even if an external impact is applied to the fused portion, the tip first hits and absorbs the impact on the electrode body side (the laminate film covering the electrode body), and even if further external impacts are applied to the fused portion afterward, the fused portion becomes less likely to deform. As a result, the impact resistance of the fused portion is improved, and consequently, damage to the electrode body can be suppressed.

[0013] Hereinafter, an embodiment of the laminate-type battery relating to this disclosure will be described with reference to the drawings. The following diagrams are schematic representations, and the size and shape of each part have been exaggerated as appropriate for ease of understanding.

[0014] (First aspect) Figure 1 is a schematic cross-sectional view illustrating a laminated battery according to this embodiment. The laminated battery 10A comprises an electrode body 2 and a laminate film 4 that covers the electrode body 2 and seals it inside. The laminate film 4 has a fused portion 40 where one end and the other end are overlapped and their inner surfaces are fused together. The electrode body 2 has a shape in which the end face 20 (shown in Figure 1 as the end face on which the fused portion 40 is formed) is inclined. The fused portion 40 is formed outward from the end that protrudes more outward on the inclined end face 20 of the electrode body 2 (the lower end of the end face 20 in Figure 1). The fusion portion 40 has a total of three bends: a right-angle bend 40a bent in an arc shape at approximately 90° from the base side of the fusion portion 40 (i.e., the position closest to the electrode body 2) to the tip side 400; a folded-back bend 40b bent in an arc shape at approximately 0°; and a tip-side bend 40c bent in an arc shape at approximately 90° at the position closest to the tip 400 of the fusion portion 40. The tip-side bend 40c is located closest to the right-angle bend 40a, which corresponds to the bend closest to the base of the fusion portion 40, among all the remaining bends (i.e., the right-angle bend 40a and the folded-back bend 40b). Here, the angle of the fused portion in this disclosure refers to the angle at the smallest angle formed by the fused portions on both sides of the bent portion.

[0015] The fusion portion 40 has a shape in which the tip 400 faces the electrode body 2. In the fusion portion 40 shown in Figure 1, the entire area of ​​the tip 400 faces the electrode body 2 in the longitudinal direction of the fusion portion 40 (depth direction in Figure 1). Here, having a shape where the tip faces the electrode body means that the tip in the fusion portion is positioned closer to the electrode body than the bent portion at the tip side.

[0016] As shown in Figure 1, the laminated battery 10A has a shape in which the tip 400 faces the electrode body 2. Let's consider the case where an impact is applied to the fused portion 40 from the outside, for example, from the right side in Figure 1. In that case, the fused portion 40 deforms starting from the right-angle bend portion 40a, and the tip 400 first hits and absorbs the impact on the electrode body 2 side (the laminate film 4 covering the electrode body 2). Subsequently, even if the fused portion 40 continues to be subjected to impact from the outside (for example, from the right side in Figure 1), the fused portion 40 is less likely to deform because the tip 400 is in contact with the electrode body 2 side. As a result, the impact resistance of the fused portion 40 is improved, and damage to the electrode body 2 due to impacts applied to the fused portion 40 can be suppressed.

[0017] Although Figure 1 shows an embodiment with three curved bends, the bends may also be angular, i.e., have corners.

[0018] Furthermore, Figure 1 shows an embodiment in which the entire area of ​​the tip 400 of the fusion portion 40 faces the electrode body 2 in the longitudinal direction, but it is sufficient for at least a portion of the tip of the fusion portion to face the electrode body. If at least a portion of the tip of the fusion portion faces the electrode body, even if an impact is applied to the fusion portion from the outside, the portion of the tip facing the electrode body will first hit and absorb the impact, thereby improving the impact resistance of the fusion portion and suppressing damage to the electrode body.

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

[0020] (Second aspect) Figure 2 is a schematic cross-sectional view illustrating a laminate-type battery according to another embodiment of this model. The laminated battery 10B comprises an electrode body 2 and a laminate film 4 that covers the electrode body 2 and seals it inside. The laminate film 4 has a fused portion 42 where one end and the other end are overlapped and their inner surfaces are fused together. The fused portion 42 has a total of five bent portions, from the base of the fused portion 42 (i.e., the position closest to the electrode body 2) to the tip 420 side, which are curved in an arc shape at an angle of approximately 90°: a right-angle bent portion 42a, curved in an arc shape at an angle of approximately 90°: a right-angle bent portion 42b, curved in an arc shape at an angle of approximately 90°: a folded-back bent portion 42c, curved in an arc shape at an angle of approximately 0°: a right-angle bent portion 42d, curved in an arc shape at an angle of approximately 90°: and a tip-side bent portion 42e, which is curved in an arc shape 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 positioned closest to the right-angle bend 40a, which corresponds to the most root-side bend of the fused portion 42, among all the remaining bends (i.e., the right-angle bends 40a, 40b, 40d, and the folded-back bend 40c).

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

[0022] As shown in Figure 2, the laminated battery 10B has a shape in which the tip 420 faces the electrode body 2. When an impact is applied to the fused portion 42 from the outside, for example, when an impact is applied to the fused portion 42 from the right side in Figure 2, the fused portion 42 deforms starting from the right-angle bend portion 42a, and the folded bend portion 42c first hits the electrode body 2 side (the laminate film 4 covering the electrode body 2). However, if the impact continues to be applied, it is thought that the folded bend portion 42c that has come into contact with the electrode body 2 side will slide and shift (shift upward in Figure 2). Subsequently, if the impact continues to be applied to the fused portion 42, the tip 420 will then hit and be caught by the electrode body 2 side (the laminate film 4 covering the electrode body 2). Subsequently, even if the fused portion 42 is subjected to further external impact (for example, from the right side in Figure 2), the tip portion 420 remains in contact with the electrode body 2, making the fused portion 42 less susceptible to deformation. This improves the impact resistance of the fused portion 42, and as a result, damage to the electrode body 2 due to impacts applied to the fused portion 42 can be suppressed.

[0023] Although Figure 2 shows an embodiment with five curved bends, the bends may also be angular, i.e., have corners. Furthermore, Figure 2 shows an embodiment in which the entire area of ​​the tip 420 of the fusion portion 42 faces the electrode body 2 in the longitudinal direction, but it is sufficient that at least a portion of the tip of the fusion portion faces the electrode body.

[0024] (Third aspect) Figure 3 is a schematic cross-sectional view illustrating a laminated battery according to another embodiment of this model. The laminated battery 10C comprises an electrode body 2 and a laminate film 4 that covers the electrode body 2 and seals it inside. The laminate film 4 has a fused portion 44 where one end and the other end are overlapped and their inner surfaces are fused together. The fused portion 44 has a total of three bent portions: a right-angle bent portion 44a that is bent in an arc shape at an angle of approximately 90° from the base of the fused portion 44 (i.e., the position closest to the electrode body 2) to the tip 440; a folded-back bent portion 44b that is bent in an arc shape at an angle of approximately 0°; and a tip-side bent portion 44c that is bent in an arc shape 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 folded-back bent portion 44b, which does not correspond to the bent portion closest to the root of the fused portion 44, among all the remaining bent portions (i.e., the right-angle bent portion 44a and the folded-back bent portion 44b).

[0025] The fused portion 44 has a shape in which its tip 440 faces the electrode body 2. In other words, the tip 440 of the fused portion 44 is positioned 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 (depth direction in Figure 3).

[0026] As shown in Figure 3, the laminated battery 10C has a shape in which the tip 440 faces the electrode body 2. Let's consider the case where an impact is applied to the fused portion 44 from the outside, for example, from the right side in Figure 3. In that case, the fused portion 44 deforms starting from the right-angle bend portion 44a, and the tip 440 first hits and absorbs the impact on the electrode body 2 side (the laminate film 4 covering the electrode body 2). Subsequently, even if the fused portion 44 continues to be subjected to impact from the outside (for example, from the right side in Figure 3), the fused portion 44 is less likely to deform because the tip 440 is in contact with the electrode body 2 side. As a result, the impact resistance of the fused portion 44 is improved, and damage to the electrode body 2 due to impacts applied to the fused portion 44 can be suppressed.

[0027] Although Figure 3 shows an embodiment with three curved bends, the bends may also be angular, i.e., have corners. Furthermore, Figure 3 shows an embodiment in which the entire area of ​​the tip 440 of the fusion portion 44 faces the electrode body 2 in the longitudinal direction, but it is sufficient that at least a portion of the tip of the fusion portion faces the electrode body.

[0028] In the first to third embodiments shown in Figures 1 to 3, the end faces of the electrode bodies are inclined surfaces, but the shape of the electrode bodies is not limited to this. For example, as shown in Figure 4, a rectangular parallelepiped electrode body 2D can also be used.

[0029] In the laminate-type battery according to the embodiment of this disclosure, the tip of the fused portion has a shape that faces the electrode body. The shortest distance between the tip of this fused portion and the laminate film covering the electrode body is preferably 0.5 mm to 5 mm, and 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 body refers, for example, to distance a1 in Figure 1, distance a2 in Figure 2, distance a3 in Figure 3, and distance a4 in Figure 4.

[0030] Figures 1 to 3 show the first to third embodiments of a laminated battery in which the electrode body is covered with a single laminate film. However, the disclosure is not limited thereto, and a laminated battery in which the electrode body is covered with multiple laminate films may also be present. For example, a laminated battery in which the electrode body is covered with two laminate films may be present, in which the ends of the two laminate films are overlapped and their inner surfaces are fused together to form a fused portion and then sealed.

[0031] <Manufacturing method for laminated batteries> Next, a method for manufacturing a laminated battery according to the embodiment of this disclosure will be described. The method for manufacturing a laminated battery comprises an electrode body and a laminate film that covers the electrode body and seals it inside, wherein the laminate film has a fused portion where the ends are overlapped and the inner surface is fused together, and the fused portion has three or more bent portions, including two or more bent portions that are bent in an angular or arc shape at an angle of 90° or less, and one tip-side bent portion that is bent in an angular or arc shape at an angle of less than 180° at the position closest to the tip of the fused portion, and the fused portion has a shape in which at least a part of the tip faces the electrode body, and the fused portion has one folded-back bent portion that is 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-back bent portion and bent in an angular or arc shape at an angle of 70° or more and less than 90°.

[0032] Then, the process involves preparing a post-fused laminate battery having a planar fused portion in which the edges of the laminate film are overlapped and their inner surfaces are fused together, A folding and bending process is performed to form a folded and bent portion in the fused portion of a fused laminate-type battery, which is bent in an angular or arc shape at an angle of 20° or less. A right-angle bending process in which a right-angle bend is formed in the region of the fusion joint closer to the root than the folded-over bend, with the bend being at an angle of 70° or more and 90° or less, in an angular or arc shape, It has, The right-angle bending process is a process in which the fused portion is bent in stages to form a right-angle bend by conveying it between each pair of rollers in a group of rollers, each roller having at least three bending 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 bending rollers that are positioned opposite the bending rollers via the fused portion. Furthermore, the right-angle bending process involves bringing the tip-side bending portion of the fused portion into contact with at least one bending roller in the roller pair group, rather than the folded-back bending portion, in order to form the tip-side bending portion.

[0033] • Manufacturing example of a laminated battery according to the first embodiment First, we will explain using the manufacturing method of the laminated battery according to the first embodiment shown in Figure 1 as an example. In the laminated battery 10A according to the first embodiment, the right-angle bend portion 40a, the folded-back bend portion 40b, and the tip-side bend portion 40c can be formed, for example, by performing the folded-back bending process and the right-angle bending process shown below.

[0034] First, a laminate-type battery having an unfolded, flat fused portion 40 (a laminate-type battery after fusion) is subjected to a bending operation to form a folded-back bent portion 40b (fold-back bending process). One example of a bending operation in the fold-back bending process is to transport the fused portion 40 in stages by conveying it between each pair of rollers in a group of roller pairs, each roller having multiple bending rollers that contact the surface of the fused portion 40 on the bent side (i.e., the valley fold side in the folded-back bent portion 40b) and have different contact angles with respect to the fused portion 40, and the same number of opposing rollers as the bending rollers that are positioned opposite the bending rollers via the fused portion 40.

[0035] Next, a bending operation is performed on the fused portion 40 in the region of the fused portion 40 closer to the root than the folded portion 40b to form a right-angle bend portion 40a (right-angle bending process). One example of a bending operation in the right-angle bending process is to transport the fused portion 40 between each pair of rollers in a group of rollers, each roller having at least three bending rollers that contact the surface of the fused portion 40 on the bending side (i.e., the valley fold side of the right-angle bend portion 40a) and have different contact angles with respect to the fused portion 40, and the same number of opposing rollers as the bending rollers, which are positioned opposite the bending rollers via the fused portion 40, thereby bending the fused portion 40 in stages.

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

[0037] In the right-angle bending process, the right-angle bent portion 40a is formed using the above-mentioned group of rollers having at least three bending rollers with different contact angles, and the tip-side bent portion 40c is formed by bringing at least one bending roller in the group of rollers into contact with the region on the tip side 400 of the fused portion 40, 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, thereby improving the impact resistance of the fused portion 40.

[0038] • Manufacturing example of a laminated battery according to the second embodiment As a method for manufacturing a laminated battery according to the second embodiment shown in Figure 2, a method is to perform a second right-angle bending step after the folding and bending step and before the right-angle bending step, or after the right-angle bending step, in addition to the manufacturing example of the laminated battery according to the first embodiment described above.

[0039] In other words, the folded-back bend portion 42c is formed in the same manner as in the manufacturing example of the laminated battery of the first embodiment (folding-back bending process), and then the right-angle bend portion 42a and the tip-side bend portion 42e are formed in the same manner as in the manufacturing example of the laminated battery of the first embodiment (right-angle bending process). After that, right-angle bend portions 42b and 42d are formed in the region between the folded-back bend portion 42c and the tip-side bend portion 42e, and in the region between the folded-back bend portion 42c and the right-angle bend portion 42a, respectively (second right-angle bending process). The bending operation in the second right-angle bending process can be described as a method of bending the fused portion 42 in stages by transporting it between each pair of rollers in a group of roller pairs having a plurality of bending rollers that contact the surface of the fused portion 42 on the bending side (i.e., the valley-fold side in the right-angle bend portion 42d) and have different contact angles with respect to the fused portion 42, and the same number of opposing rollers as the bending rollers that are provided at a position facing the bending roller via the fused portion 42. The second right-angle bending process may be performed after the folding bending process and before the right-angle bending process.

[0040] According to the manufacturing example of the laminated battery of the second embodiment shown above, the occurrence of springback in the fused portion 42 can be suppressed. In addition, at least a portion 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 embodiments of this disclosure is not limited to the method described above. For example, a method for manufacturing the laminated battery according to the third embodiment shown in Figure 3 is to form the right-angle bent portion 44a, the folded-back bent portion 44b, and the tip-side bent portion 44c by separate bending processes.

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

[0043] (1) Laminating film Examples of laminate films include films having a metal layer, and further, films with a three-layer structure having resin layers on both sides of the metal layer. In the three-layer film, the inner resin layer on the electrode side (i.e., the resin layer to be fused) is designated as the fusion resin layer, and the resin layer on the outer surface opposite the electrode side is designated as 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 to 100 μm. The thickness of the metal layer is, for example, 30 μm to 60 μm. The thickness of the protective resin layer is, for example, 20 μm to 60 μm. The overall thickness of the laminate film is, for example, 70 μm to 220 μm.

[0045] (2) Electrode body The electrode body functions as a power generation element of the battery. The shape of the electrode body is not particularly limited, but examples include a rectangular parallelepiped shape, a shape with inclined end faces, etc. The electrode body usually 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.

[0046] The positive electrode active material layer contains at least one 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, particulate. Examples of positive electrode active materials include oxide active materials. Sulfur (S) may also be used as the positive electrode active material.

[0047] Preferably, the positive electrode active material contains a lithium composite oxide. The lithium composite oxide may contain at least one selected from the group consisting of F, Cl, N, S, Br, and I. Further, 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 and P6 / mmc). Further, the main arrangement of transition metal, oxygen, and lithium in the lithium composite oxide may be an O2-type structure.

[0048] Examples of the lithium composite oxide having a crystal structure belonging to R-3m include, for example, Li x Me y O α X β (where 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, X represents at least one selected from the group consisting of F, Cl, N, S, Br, and I, and 0.5 ≦ x ≦ 1.5, 0.5 ≦ y ≦ 1.0, 1 ≦ α < 2, 0 < β ≦ 1 are satisfied). Compounds represented by this are exemplified.

[0049] Examples of the lithium composite oxide having a crystal structure belonging to Immm include, for example, Li x1 M 1 A 1 2 (satisfying 1.5 ≦ x1 ≦ 2.3, M 1 includes at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, A 1 includes at least oxygen, and the ratio of oxygen in A 1 is 85 atomic% or more). Composite oxides represented by this (specific example: Li2NiO2), Li 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 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 include composite oxides represented by the following formula.

[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 of the composite oxide represented by this formula are as follows.

[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 (where 0.5 < x < 1.1, 0.1 < α < 0.3, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi).) Examples of the composite oxide represented by this formula include, specifically, Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Niy 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 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 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[[ID=**5**]] 2-x Nb x )O 12 (0≦x≦2), Li5La3Nb2O 12 etc. 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 suppressing, for example, 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 preferred. 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-like or mesh-like.

[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-like and mesh-like.

[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-state 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. A solid-state battery may have, for example, the cross-sectional structure shown in Figure 5, and the solid electrolyte layer B may have a two-layer structure as shown in Figure 5. Figure 5 is a schematic cross-sectional view showing an example of a solid-state battery. The solid-state battery shown in Figure 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 LiNbO3 electrolyte. Furthermore, the solid-state battery may be constructed by sealing the laminated end faces (sides) of the positive electrode / solid electrolyte layer / negative electrode laminated structure with resin. The current collector of the electrode may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer arranged on its surface.

[0064] ·battery The laminated battery in this disclosure is typically a lithium-ion secondary battery. Applications of the battery include, for example, powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline cars, and diesel cars. It is particularly preferable for the battery to be used as a power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). Furthermore, the battery in this disclosure may be used as a power source for mobile devices other than vehicles (e.g., railways, ships, aircraft), or as a power source for electrical products such as information processing devices.

[0065] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this 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 and bent section 40c, 42e, 44c Tip-side bend 400, 420, 440 tip 101 Negative electrode active material 103 Coated positive electrode active material 105, 107 Conductive additives 109, 111 Binders 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. Electrode body and It comprises a laminate film that covers the electrode body and seals it inside, The laminate film has a fused portion where the edges are overlapped and the inner surfaces are fused together. The fused portion has three or more bent portions, including two or more bent portions that are bent in an angular or arc shape at an angle of 90° or less, and one tip-side bent portion that is bent in an angular or arc shape at an angle of less than 180° at the position closest to the tip of the fused portion. The fused portion has a shape in which at least a portion of its tip faces the electrode body side, in a laminate-type battery.

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

3. The laminated battery according to claim 1, wherein the position where the tip-side bent portion is located is the position closest to the base-side bent portion among the two or more bent portions.

4. The laminate battery according to claim 1, wherein the shortest distance between the tip of the fusion portion and the laminate film covering the electrode body is 0.5 mm or more and 5 mm or less.

5. The laminated battery according to claim 1, wherein the fused portion has, as the bent portion, one folded-back bent portion that is 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-back bent portion and bent in an angular or arc shape at an angle of 70° or more and 90° or less.

6. A method for manufacturing a laminated battery according to claim 5, A process for preparing a post-fusion laminated battery having a planar fused portion in which the edges of laminate films are overlapped and their inner surfaces are fused, A folding and bending step is performed to form a folded and bent portion in the fused portion of the fused laminate-type battery, which is bent in an angular or arc shape at an angle of 20° or less. A right-angle bending step is performed to form a right-angle bend in the region of the fused portion closer to the root than the folded-back bend, which is bent in an angular or arc shape at an angle of 70° or more and 90° or less. It has, The right-angle bending process is a process of forming the right-angle bend by conveying the fused portion between each pair of rollers in a group of roller pairs, each roller having at least three bending 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 bending rollers that are positioned opposite the bending rollers via the fused portion. A method for manufacturing a laminate-type battery, wherein the right-angle bending step is a step of bringing the region of the fused portion closer to the tip than the folded-back bending portion into contact with at least one bending roller in the group of rollers, thereby forming the tip-side bending portion.

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