Laminated battery, battery module, and method for manufacturing laminated battery

Abstract

To provide a laminate type battery in which a damage of a metal layer in a laminate exterior package at a position opposite to an approximately right-angled shape part of a battery element is suppressed and the high airtightness of the battery element by the laminate exterior package is achieved.SOLUTION: A laminate type battery 100 includes a battery element and a laminate exterior package 800 in which the battery element is sealed. The laminate exterior package 800 is formed by stacking at least a resin layer and a metal layer. The battery element includes approximately right-angled shape parts K1, K2, K3, and K4, and a horizontal part with a horizontal shape. In a part of the metal layer corresponding to 80% or more of the metal layer of the laminate exterior package opposite to the approximately right-angled shape parts K1, K2, K3, and K4 of the battery element, a thickness T1 of the metal layer and a thickness T2 of the metal layer of the laminate exterior package opposite to the horizontal part of the battery element satisfy the relation of |T1-T2| / T2×100(%)≤10%.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Batteries such as lithium ion secondary batteries typically include an electrode assembly having 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. The electrode assembly is sealed in an internal space surrounded by, for example, an exterior material. Patent Document 1 discloses a lithium polymer secondary battery that includes an electrode assembly, an exterior material surrounding the outside of the electrode assembly, and first and second covers that seal the exterior material, with a first electrode terminal and a second electrode terminal extending to the outside via the first cover and the second cover, respectively. Patent Document 1 also describes a laminate film as the exterior body. Patent Document 2 describes a laminated battery that uses a laminated film that has been embossed in advance to match the shape of the electrode body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-108623 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-174555 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 2 describes the use of a laminate film embossed in advance to match the shape of the electrode body corresponding to the battery element as the laminate exterior body for a laminated battery. However, when embossing is performed, the laminate exterior body stretches at the embossed areas, which reduces the thickness of the metal layer in the laminate exterior body at the position facing the approximately right-angled portion of the battery element, and this thinned area can cause breakage. As a result, the sealing ability of the battery element by the laminate exterior body is reduced.

[0005] The present disclosure has been made in consideration of the above-described situation, and aims to provide a laminated battery that suppresses breakage of the metal layer in the laminated outer casing at a position opposite the approximately right-angled portion of the battery element and achieves high sealing of the battery element by the laminated outer casing, a battery module including the laminated battery, and a method for manufacturing the laminated battery. [Means for solving the problem]

[0006] Means for solving the above problems include the following aspects. <1> Battery element and a laminated exterior body that encapsulates the battery element, The laminate exterior body is formed by laminating at least a resin layer and a metal layer, the battery element includes a substantially right-angled portion having an angle of 80° or more and 100° or less, and a horizontal portion having a horizontal shape; A laminated battery, wherein in 80% or more of the metal layers of the laminated outer casing that face the approximately rectangular portion of the battery element, the thickness T1 of the metal layers satisfies the following relationship with the thickness T2 of the metal layer of the laminated outer casing that faces the horizontal portion of the battery element: |T1-T2| / T2×100(%)≦10% Formula <2> a ratio (|T3-T2| / T2×100(%)) of the difference between a thickness T3 of the metal layer at a position in the laminate exterior body that faces the horizontal portion of the battery element and that is 1 mm from a position that faces the approximately right-angled portion of the battery element and a thickness T2 of the metal layer of the laminate exterior body that faces the horizontal portion of the battery element is within 10%; <1> 2. The laminated battery according to claim 1. <3> the laminate exterior body has three or more mountain-shaped bent portions and one or more valley-shaped bent portions at positions facing the substantially right-angled portion of the battery element; <1> or <2> 2. The laminated battery according to claim 1. <4> A battery module having a plurality of laminated type batteries stacked in the thickness direction, The laminated battery comprises: <1> ~ <3> 10. A battery module comprising the laminated battery according to any one of claims 1 to 9. <5> a battery element including a substantially right-angled portion having an angle of 80° or more and 100° or less and a horizontal portion having a horizontal shape; a laminated outer casing that encapsulates the battery element and is formed by laminating at least a resin layer and a metal layer, a folding step of forming a folding line by folding molding at a position of the laminate exterior body that faces the substantially rectangular portion of the battery element when the battery element is enclosed; an encapsulation step of encapsulating the battery element in the laminate exterior body having the folding line; A method for manufacturing a laminated battery having the above structure. <6> the battery element includes an electrode body and a side surface member disposed on a side surface of the electrode body, In the folding step, when forming the folding line in the laminate exterior body, the folding line is not formed at a position of the laminate exterior body facing the side member. <5> A method for manufacturing the laminated battery according to claim 1. <7> In the folding process, a mold having an arc-shaped surface on a part of a surface that comes into contact with the laminate exterior body is used, the arc-shaped surface contacts a position of the laminate exterior body that faces the horizontal portion of the battery element when the battery element is enclosed. <5> or <6> A method for manufacturing the laminated battery according to claim 1. <8> the laminated exterior body after the encapsulation step has three or more mountain-shaped folds and one or more valley-shaped folds at positions facing the substantially right-angled portion of the battery element; <5> ~ <7> 10. A method for producing the laminated battery according to claim 9. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a laminated battery that suppresses breakage of the metal layer in the laminated outer casing at a position opposite the approximately right-angled portion of the battery element and achieves high sealing of the battery element by the laminated outer casing, a battery module including the laminated battery, and a method for manufacturing the laminated battery. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view illustrating a battery element according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic perspective view illustrating a battery element enclosed in a laminate exterior body according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic cross-sectional view showing the cross section XX in FIG. 2. [Figure 4] 10A to 10C are schematic cross-sectional views for explaining a bending step in an embodiment of the present disclosure. [Figure 5] 10A to 10C are schematic cross-sectional views for explaining a bending step in an embodiment of the present disclosure. [Figure 6] FIG. 2 is a schematic cross-sectional view showing a mold used in a bending step in an embodiment of the present disclosure. [Figure 7]FIG. 10 is a schematic top view showing a laminate exterior body in which a folded portion is not formed at a position facing a side member. [Figure 8] 10A and 10B are schematic cross-sectional views for explaining a bending step in another embodiment of the present disclosure. [Figure 9] 10A and 10B are schematic cross-sectional views for explaining a bending step in another embodiment of the present disclosure. [Figure 10] 1 is a top view of a laminate film after embossing in Comparative Example 1, a cross-sectional view of the LL cross section in the top view, and a cross-sectional view of the MM cross section in the top view. [Figure 11] FIG. 1 is a schematic cross-sectional view showing an example of a solid-state battery. DETAILED DESCRIPTION OF THE INVENTION

[0009] The battery of the present disclosure will be described in detail below with reference to the drawings. The following drawings are schematic illustrations, and the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, in this specification, when describing an arrangement of another member relative to a certain member, the term "above" or "below" refers to both an arrangement of another member directly above or below the certain member, in contact with the certain member, and an arrangement of another member above or below the certain member via another member, unless otherwise specified.

[0010] A. Laminated battery An embodiment of a laminated battery (hereinafter also simply referred to as "battery") according to the present disclosure will be described with reference to FIGS. 1 to 3. FIG. Fig. 1 is a schematic perspective view illustrating a battery element according to an embodiment of the present disclosure. Fig. 2 is a schematic perspective view illustrating a battery element enclosed in a laminate exterior body according to an embodiment of the present disclosure. Fig. 3 is a schematic cross-sectional view showing the XX cross section in Fig. 2.

[0011] As shown in Fig. 1, a battery 100 according to an embodiment of the present disclosure has, as battery elements, an electrode body 11 and a side member 20 (e.g., a current collecting terminal) arranged on a side surface of the electrode body 11. As shown in Fig. 2, this battery element is encapsulated in a laminate film 800, which is a laminate exterior body. That is, all four surfaces of the electrode body 11 other than the side surface on which the side member 20 is arranged are covered with the laminate film 800, and the side surface of the electrode body 11 is covered by the side member 20 and the laminate film 800, thereby encapsulating the electrode body 11. A partial area of ​​the side surface member 20 on the electrode body 11 side is covered with the laminate film 800.

[0012] The laminate film 800 is made of a single film, and is formed by laminating a resin layer and a metal layer. For example, the laminate film 800 is a three-layer laminate having, in order from the inner surface side facing the electrode body 11, a fusion resin layer, a metal layer, and a protective resin layer. The laminate film 800 has a fusion portion Y where the ends are overlapped and fused together while wrapping the electrode body 11. Although Figures 2 and 3 show an embodiment in which the laminated outer casing is composed of a single laminate film 800, this is not limited to this, and in the present disclosure the laminated outer casing may be composed of multiple laminate films.

[0013] 3, the electrode body 11 constituting the battery element has four corners K1, K2, K3, and K4 that correspond to substantially right-angled portions, and all four surfaces sandwiched between two of the corners K1, K2, K3, and K4 form horizontal portions that are horizontal. Furthermore, the positions of the laminate film 800 facing the corners K1, K2, K3, and K4 of the electrode body 11 form bent portions K11, K12, K13, and K14, each of which is substantially right-angled. The bent portions K11, K12, and K13 are mountain folds, while the bent portion K14 is a valley fold that is bent toward the fused portion Y. In other words, the laminate film 800 has three or more mountain folds and one or more valley folds at positions facing the four corners K1, K2, K3, and K4 of the electrode body 11, which correspond to the approximately right-angled portions of the electrode body 11. Although FIG. 3 shows an embodiment in which all of the corners K1, K2, K3, and K4 are right angles, the angle of the substantially right-angled portions may be between 80° and 100°.

[0014] In the battery 100 according to the embodiment of the present disclosure, the ratio (|T1-T2| / T2×100(%)) of the absolute value of the difference between the thickness T1 of the metal layer at the folded portions K11, K12, K13, and K14 of the laminate film 800 and the thickness T2 of the metal layer at the laminate film 800 facing the four horizontal portions of the electrode assembly 11 to T2 is within 10%. Furthermore, in the present disclosure, the ratio of the portions of the metal layer that satisfy the condition that the formula (|T1-T2| / T2×100(%)) is within 10% is 80% or more of all the portions of the metal layer of the laminate exterior body that face the substantially rectangular portions of the battery element. In the battery 100 shown in FIG. 3, T1 at each of the four folded portions K11, K12, K13, and K14 is within 10% of T2. That is, the condition that the formula (|T1-T2| / T2×100(%)) is within 10% is satisfied at 100% of the four bending portions K11, K12, K13, and K14.

[0015] Conventionally, when manufacturing a laminated battery in which a battery element is enclosed in a laminate outer casing, a process is performed to form a shape conforming to the approximately right-angled portion of the battery element at a position of the laminate outer casing opposite the approximately right-angled portion. Embossing has been a conventional method for forming a shape conforming to the approximately right-angled portion. However, when embossing is performed, the laminate outer casing stretches at the processed portion, so that the thickness of the metal layer at the position of the laminate outer casing opposite the approximately right-angled portion of the battery element becomes thinner than in other regions (e.g., the position of the laminate outer casing opposite the horizontal portion of the battery element). As a result, breakage occurs at the position where the metal layer is thinner opposite the approximately right-angled portion of the laminate outer casing, which can reduce the sealing ability of the battery element by the laminate outer casing.

[0016] In contrast, in the battery 100 according to the embodiment of the present disclosure, there is a small difference in the thickness of the metal layer between the folded portions K11, K12, K13, and K14 of the laminate film 800 and the positions facing the horizontal portion of the electrode body 11. This makes it possible to suppress breakage of the laminate film 800 at the folded portions K11, K12, K13, and K14, and to improve the sealing performance of the electrode body 11 by the laminate film 800.

[0017] (Thickness difference) In the present disclosure, there is a small difference between the thickness of the metal layer of the laminate exterior body facing the substantially rectangular portion of the battery element and the thickness of the metal layer of the laminate exterior body facing the horizontal portion of the battery element. Specifically, the ratio of the difference (|T1-T2| / T2×100(%)) between the thickness T1 of the metal layer of the laminate exterior body facing the substantially rectangular portion of the battery element and the thickness T2 of the metal layer of the laminate exterior body facing the horizontal portion of the battery element is 10% or less. From the viewpoint of suppressing damage to the metal layer of the laminate exterior body at the position facing the substantially rectangular portion of the battery element and improving the sealing performance of the battery element by the laminate exterior body, it is preferable that the ratio of the difference (|T1-T2| / T2×100(%)) be 5% or less, and even more preferably 3% or less.

[0018] The thickness T1 of the metal layer of the laminate outer casing facing the substantially right-angled portion of the battery element is determined by measuring the thickness of the metal layer of the laminate outer casing at any five locations at a position facing one of the substantially right-angled portions of the battery element (for example, one of the bending portions K11, K12, K13, and K14 in FIG. 3), and calculating the average value to obtain the thickness T1. This is performed for all positions facing the substantially right-angled portions of the battery element (for example, all of the bending portions K11, K12, K13, and K14 in FIG. 3), to obtain the thickness T1 at each location. Furthermore, the thickness T2 of the metal layer of the laminate exterior body facing the horizontal portion of the battery element is determined by measuring the thickness of the metal layer of the laminate exterior body at any five points at a position facing one horizontal portion of the battery element (for example, in FIG. 3, one horizontal region sandwiched between two of the bent portions K11, K12, K13, and K14).Furthermore, the thickness of the metal layer is similarly measured at any five points at positions facing all horizontal portions of the battery element (for example, in FIG. 3, all horizontal regions sandwiched between two of the bent portions K11, K12, K13, and K14), and the average value of the measurements at all these measurement points is calculated and defined as thickness T2. In the present disclosure, the ratio of the difference between thickness T1 and thickness T2 (|T1-T2| / T2×100(%)) is within the above range at 80% or more of the positions facing all of the substantially right-angled portions in the battery element (for example, all of the bent portions K11, K12, K13, and K14 in FIG. 3). Note that it is preferable that the ratio of the difference between thickness T1 and thickness T2 (|T1-T2| / T2×100(%)) is within the above range at all positions (100% positions) facing the substantially right-angled portions.

[0019] In the present disclosure, it is also preferable that the difference between the thickness of the metal layer of the laminate outer casing near the position facing the substantially rectangular portion of the battery element and the thickness of the metal layer of the laminate outer casing facing the horizontal portion of the battery element is small. Specifically, the ratio of the difference (|T3-T2| / T2×100(%)) between the thickness T3 of the metal layer of the laminate outer casing at a position facing the horizontal portion of the battery element and 1 mm from the position facing the substantially rectangular portion of the battery element and the thickness T2 of the metal layer of the laminate outer casing facing the horizontal portion of the battery element is preferably within 10%. Note that, from the viewpoint of suppressing damage to the metal layer of the laminate outer casing at the position facing the substantially rectangular portion of the battery element and its vicinity and improving the sealing performance of the battery element by the laminate outer casing, it is more preferable that the difference ratio (|T3-T2| / T2×100(%)) be within 5%, and even more preferably within 3%.

[0020] The thickness T3 of the metal layer at a position on the laminate outer casing opposite the horizontal portion of the battery element and 1 mm from the position opposite the substantially right-angled portion of the battery element is determined by measuring the thickness of the metal layer at any five positions on the laminate outer casing at the above-mentioned distance from the position opposite one of the substantially right-angled portions of the battery element (for example, one of the bends K11, K12, K13, and K14 in FIG. 3), and calculating the average value to obtain the thickness T3. This is performed for all positions opposite the substantially right-angled portions of the battery element (for example, all of the bends K11, K12, K13, and K14 in FIG. 3), to obtain the thickness T3 at each position.

[0021] B. Manufacturing method of laminated battery The method for manufacturing a laminated battery according to the present disclosure is a method for manufacturing a laminated battery having a battery element including a substantially rectangular portion and a horizontal portion, and a laminated exterior body that encapsulates the battery element and is formed by laminating at least a resin layer and a metal layer. The method for manufacturing a laminated battery includes a folding step of forming a fold line by folding molding in a position of the laminated exterior body that faces the substantially rectangular portion of the battery element when the battery element is encapsulated, and an encapsulation step of encapsulating the battery element in the laminated exterior body having the fold line.

[0022] Here, one embodiment of the folding step in the method for manufacturing a laminated battery according to the present disclosure will be described with reference to FIGS. 4 and 5 are schematic cross-sectional views for explaining the bending process in the embodiment of the present disclosure.

[0023] As shown in Fig. 4, the folding process in the embodiment of the present disclosure uses a mold including an upper mold 2 and a lower mold having a left core 41, a right core 42, and a base 6. The film 8 to be formed into the laminate outer casing is placed on the left core 41 and the right core 42 of the lower mold before folding. Next, the upper mold 2 is lowered in the direction of arrow A relative to the film 8. Furthermore, as shown in Fig. 5, the film 8 is folded by applying pressure from the left core 41 to the film 8 in the direction of arrow B1, and from the right core 42 to the film 8 in the direction of arrow B2, thereby obtaining a laminate film 80 having the shape shown in Fig. 5.

[0024] After the folding process, the laminate film 80 has four folding portions 82a, 82b, 82c, and 82d and five surfaces 81a, 81b, 81c, 81d, and 81e. After the electrode body 11 is enclosed, the folding portion 82a of the laminate film 80 corresponds to the folding portion K13 in Fig. 3, the folding portion 82b corresponds to the folding portion K12 in Fig. 3, the folding portion 82c corresponds to the folding portion K11 in Fig. 3, and the folding portion 82d corresponds to the folding portion K14 in Fig. 3. Furthermore, the surfaces 81a, 81b, 81c, and 81d become surfaces that form the horizontal portion, and the surface 81e overlaps with the end of the surface 81a to form the fused portion Y.

[0025] In the mold shown in FIGS. 4 and 5, part of the surface of the right core 42 in the lower mold that comes into contact with the laminate film 80, specifically the area that forms the surface 81c, is an arc-shaped surface. The mold used in the bending process has an arc-shaped surface in the area of ​​the laminate exterior body that faces the horizontal portion of the battery element when the battery element is sealed, which enables the bending process to be performed all at once. Furthermore, the presence of the arc-shaped surface allows for higher accuracy in the position of the bent portion compared to a mold without an arc-shaped surface. The mold may have two or more arc-shaped surfaces in the region of the laminate exterior body that faces the horizontal portion of the battery element when the battery element is enclosed.

[0026] 4 and 5, the clearance (i.e., the gap between the molds) when bending is performed by lowering upper mold 2 in the direction of arrow A relative to film 8, and then applying pressure from left core 41 to film 8 in the direction of arrow B1 and from right core 42 to film 8 in the direction of arrow B2 to perform the bending process will be described below. To explain the clearance in the molds, Fig. 6 is a schematic cross-sectional view showing only upper mold 2, left core 41, right core 42, and a lower mold having a base 6, without showing the laminate film.

[0027] The widths of the clearances C1, C2, and C3 shown in FIG. 6 are preferably 0 μm. That is, at the position of the clearance C1, the upper mold 2 and the left core 41 preferably contact each other when no laminate film is present. Similarly, at the position of the clearance C2, the upper mold 2 and the base 6 preferably contact each other when no laminate film is present, and at the position of the clearance C3, the upper mold 2 and the right core 42 preferably contact each other when no laminate film is present. When encapsulating the battery elements (e.g., the electrode body 11 and the side member 20 in FIG. 2) with a laminate film, it is desirable that the laminate film 80 be folded firmly at two points, 82a and 82b, in FIG. 5. By setting the widths of the clearances C1, C2, and C3 to 0 μm, the folding of the two points, 82a and 82b, can be performed well.

[0028] 6 is preferably greater than or equal to (laminate film thickness + 10 μm) and less than or equal to (laminate film thickness + 100 μm), and more preferably greater than or equal to (laminate film thickness + 30 μm) and less than or equal to (laminate film thickness + 70 μm). By keeping the widths of clearances C4, C5, and C6 within the above ranges, damage to the laminate film due to pressure from the mold at bending portions 82c, 82d, and 82e can be suppressed.

[0029] When forming folding portions 82a, 82b, 82c, and 82d in the laminate film 80 in the folding step, it is preferable not to form folding portions in positions of the laminate film 80 that face the side surface member 20. That is, as shown in Fig. 7, folding lines B are formed in positions of the laminate film 80 that face the four corners K1, K2, K3, and K4 that correspond to the approximately right-angled portions of the electrode body 11 (positions that will become folding portions K11, K12, K13, and K14), while a region NB where no folding lines are formed is preferably formed in a position facing the side surface member 20. Here, the position of the laminate film 80 that faces the side surface member corresponds to a region of the laminate film 800 that covers a portion of the side surface member 20 on the electrode body 11 side in the battery 100 in which the electrode body 11 is covered by the laminate film 800 shown in Fig. 2. In the folding process, a folding portion (e.g., folding line B) is formed at a position facing the approximately rectangular portion of the battery element, and a folding line can also be formed at a position facing the side member on the extension of that folding line. However, the side member (e.g., current collector terminal) is generally smaller in size than the electrode body constituting the battery element. Therefore, the folding line formed at a position facing the side member does not face the corner of the side member, and fold marks remain at positions that do not face the corners of the side member. These fold marks can cause damage to the laminate exterior body. Therefore, in the folding process, it is preferable not to form a folding line at a position facing the side member of the laminate exterior body. This can prevent damage to the laminate film due to fold marks.

[0030] In addition, as a method for not forming a folded portion at the position of laminate film 80 facing side surface member 20 in the folding process, there is a method of using a mold that is narrower than the width of film 8 before folding. In other words, by using a mold that is the same width as the length of folding line B shown in Fig. 7 and film 8 that is wider than this mold, folding can be performed without forming a folded portion at the position of laminate film 80 facing side surface member 20.

[0031] Next, another embodiment of the folding step in the method for manufacturing a laminated battery according to the present disclosure will be described with reference to FIGS. 8 and 9 are schematic cross-sectional views for explaining a bending step in another embodiment of the present disclosure.

[0032] As shown in Fig. 8, a folding process in another embodiment of the present disclosure uses a mold including an upper mold 12 and a lower mold 16. First, film 18, which will become the laminated outer casing, before folding is placed on lower mold 16. Next, upper mold 12 is lowered in the direction of arrow D onto film 18 to apply pressure, thereby folding film 18 and obtaining laminated film 180 having the shape shown in Fig. 9.

[0033] After the folding process, laminate film 180 has four folding portions 182a, 182b, 182c, and 182d and five surfaces 181a, 181b, 181c, 181d, and 181e. After the electrode body 11 is enclosed, folding portion 182a of laminate film 180 corresponds to folding portion K13 in Fig. 3, folding portion 182b corresponds to folding portion K12 in Fig. 3, folding portion 182c corresponds to folding portion K11 in Fig. 3, and folding portion 182d corresponds to folding portion K14 in Fig. 3. Furthermore, surfaces 181a, 181b, 181c, and 181d become surfaces that form the horizontal portion, and surface 181e is overlapped with the end of surface 181a to form fusion portion Y.

[0034] C. Battery components (1) Battery element The battery element in the present disclosure includes, for example, an electrode assembly, which typically includes 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.

[0035] 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.

[0036] 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.

[0037] 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.)

[0038] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 2(1.5≦x1≦2.3, M 1 contains at least one selected from the group consisting of Ni, Co, Mn, Cu and Fe, and A 1 contains at least oxygen, and A 1 The ratio of oxygen in the oxide is 85 atomic % or more.x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0 ≦ x2 ≦ 0.5, 0 ≦ y ≦ 0.3, and at least one of x2 and y is not zero, and M 1A represents at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, and M 1B represents at least one selected from the group consisting of Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta, and W, and A2 represents at least one selected from the group consisting of F, Cl, Br, S, and P.) Examples include composite oxides represented by the following formula.

[0039] 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 x + y satisfies 0 < x + y ≦ 2.) Examples include composite oxides represented by the following formula.

[0040] 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 < 0.33, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi.) Examples include composite oxides represented by the following formula, and specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 and the like.

[0041] 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, and 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.

[0042] 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.

[0043] 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 active material is, for example, particulate or foil-like. The conductive material, electrolyte, and binder are the same as described above.

[0044] 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.

[0045] 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.

[0046] 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 with 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 with 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 with at least one selected from the group consisting of Na, K, Mg, Ca, and Zn. A part of S may be substituted with a halogen. The halogen is at least one of F, Cl, Br, and I.

[0047] 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 , 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 substituted with N), and examples of the Li-B-O-based solid electrolyte include Li3BO3, a compound in which a part of O in Li3BO3 is substituted with C, etc.

[0048] 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 oxidative decomposition of the sulfide solid electrolyte, etc.

[0049] The positive electrode current collector conducts current collection for the positive electrode active material layer. Examples of the material of the positive electrode current collector include metals such as aluminum, SUS, nickel, iron, titanium, etc., and 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. Examples of the shape of the positive electrode current collector include a foil shape and a mesh shape. The positive electrode current collector may have a positive electrode tab for connecting to the positive electrode current collection terminal.

[0050] The negative electrode current collector conducts current collection for 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 a foil shape and a mesh shape. The negative electrode current collector may have a negative electrode tab for connecting to the negative electrode current collection terminal.

[0051] The battery element in the present disclosure may have, for example, a side member. The side member is disposed on the side surface portion of the electrode body. The side member is not particularly limited as long as it is a member disposed on the side surface portion of the electrode body, but it is preferably a current collection terminal. The current collection terminal refers to a terminal having a current collection portion at least partially. The current collection portion is, for example, electrically connected to the tab in the electrode body. The current collection terminal may be entirely a current collection portion or partially a current collection portion. Further, the side member may be an exterior member having no current collection function.

[0052] Examples of the material of the side member include metals such as SUS, etc. Further, an aspect in which the side member has a coating resin layer on the surface in contact with the laminate film is exemplified. Examples of the material of the coating resin layer include olefin resins such as polypropylene (PP), polyethylene (PE), etc. The thickness of the coating resin layer is, for example, 40 μm or more and 150 μm or less.

[0053] (3) Laminate exterior body An example of the laminate exterior body in the present disclosure is a laminate film. The laminate film has a structure having at least a resin layer and a metal layer, and for example, has a structure in which a fusion resin layer (heat-sealing layer) is provided on one surface of the metal layer (the inner surface side forming the fusion portion). The laminate film may also have a fusion resin layer (heat-sealing layer), a metal layer, and a protective resin layer in this order along the thickness direction. Examples of materials for the fusion resin layer (heat-sealing layer) include olefin-based 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 (heat-sealing 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 total thickness of the laminate film is, for example, 70 μm or more and 220 μm or less.

[0054] (4)Battery The battery in the present disclosure is typically a lithium ion secondary battery, and is preferably a solid-state battery, including so-called all-solid-state batteries that use an inorganic solid electrolyte as the electrolyte.

[0055] The solid-state battery has a laminated structure of a positive electrode, a solid electrolyte layer, and a negative electrode. 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. 11, and the solid electrolyte layer B may have a two-layer structure as shown in FIG. 11. FIG. 11 is a schematic cross-sectional view showing an example of a solid-state battery. The solid-state battery shown in FIG. 11 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.

[0056] 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 vehicles, and diesel-powered vehicles. It is particularly preferable for the battery to be used as a driving power source for HEVs, PHEVs, or BEVs. The battery of 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.

[0057] D. Battery module The battery module according to the present disclosure includes a plurality of batteries stacked in the thickness direction, the batteries being the same as those described above in "A. Laminated Battery."

[0058] The battery in the present disclosure is similar to that described above in "A. Battery," and therefore will not be described here. The battery module in the present disclosure may also have a restraining jig that restrains multiple batteries in the thickness direction. The type of restraining jig is not particularly limited, but examples include a jig that applies restraining torque using a bolt. The restraining pressure applied by the restraining jig is, for example, 1 MPa or more and 50 MPa or less.

[0059] 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. [Example]

[0060] The present disclosure will be explained in more detail below with reference to examples.

[0061] [Example 1] As a laminate film, a laminate was prepared having, from the inner surface side that will be the electrode body side when the electrode body is encapsulated, a fusion resin layer consisting of a 40 μm polypropylene (PP) layer and a 40 μm acid-modified polypropylene (PPa) layer, a metal layer consisting of a 40 μm aluminum (Al) layer, and a protective resin layer consisting of a 15 μm oriented nylon (ONy) layer, a 1 μm adhesive layer, and a 12 μm polyethylene terephthalate (PET) layer.

[0062] The laminate film was folded using the molds shown in Figures 4 and 5. That is, the laminate film was placed on the left core 41 and right core 42 of the lower mold, and then the upper mold 2 was lowered in the direction of arrow A. Furthermore, as shown in Figure 5, the left core 41 applied pressure in the direction of arrow B1, and the right core 42 applied pressure in the direction of arrow B2, thereby folding the laminate film, and obtaining the laminate film with the shape shown in Figure 5. After folding, the laminate film had four folded portions 82a, 82b, 82c, and 82d and five faces 81a, 81b, 81c, 81d, and 81e. Next, the folded laminate film was used to encapsulate the electrode body 11 having current collector terminals as side members 20 on the side surfaces, thereby obtaining a battery.

[0063] In this battery, the thickness of the metal layer (Al layer) at each of the bent portions K11, K12, K13, and K14 in Figure 3 was measured at five random locations, and the average value was calculated to be the thickness T1 of the metal layer at each of the bent portions K11, K12, K13, and K14. In addition, for each of the four horizontal regions sandwiched between two of the folding portions K11, K12, K13, and K14 in Figure 3, the thickness of the metal layer of the laminate film was measured at five arbitrary locations, and the average of the measurements at all 20 locations (5 measurement points x 4 horizontal regions) was calculated to obtain the thickness T2 of the metal layer at the horizontal portion. The results are shown in Table 1.

[0064] [Comparative Example 1] The same laminate film as in Example 1 was used and embossed to form the shape shown in Fig. 10. Fig. 10 shows a top view of laminate film 280 after embossing in Comparative Example 1, a cross-sectional view of the LL section in the top view (the upper view in Fig. 10), and a cross-sectional view of the MM section in the top view (the left view in Fig. 10). Laminate film 280 in the shape shown in Fig. 10 is folded at a central fold N to enclose electrode bodies in opposing recesses, and the edges are laminated to form a laminated battery.

[0065] The laminate film 280 has an embossed portion 282. The thickness of the metal layer (Al layer) at each of points P1, P2, and P3, which correspond to the folded portions, was measured at three arbitrary locations, and the average value was calculated to be the thickness T1 of the metal layer at points P1, P2, and P3. In addition, in Figure 10, the thickness of the metal layer of the laminate film 280 near the center of the horizontal portion (i.e., near the central position farthest from all embossed portions in the horizontal portion surrounded by embossed portions) was measured at three random locations, and the average value was calculated to be the thickness T2 of the metal layer in the horizontal portion. The results are shown in Table 2.

[0066] [Table 1]

[0067] [Table 2]

[0068] (Metal layer thickness at horizontal part near bend) Next, the thickness of the metal layer was measured at the horizontal portion near the folded portion of the laminate film. First, in Comparative Example 1, for the laminate film 280, the thickness T3 of the metal layer (Al layer) was measured at each of points P11, P12, P13, P14, P15, and P16, which correspond to the horizontal portion of the valley portion formed near the central folding portion N, i.e., points located midway between the bottom folding portion and the peak folding portion of the valley portion.

[0069] In Example 1, the thickness T3 of the metal layer (Al layer) of the laminate film was measured at one location on each side of the folded portions K11, K12, K13, and K14, at horizontal portions 1 mm apart, for a total of eight measurement locations, which correspond to a, b, c, d, e, f, g, and h in Figure 3. The results are shown in Tables 3 and 4.

[0070] [Table 3]

[0071] [Table 4]

[0072] As shown in Tables 1 and 2, in Example 1, in which a folded portion was formed in the laminate film by folding processing, the thickness of the metal layer at the folded portion was prevented from becoming thinner than in Comparative Example 1, in which the folded portion was formed by embossing processing. Furthermore, as shown in Tables 3 and 4, in Example 1, in which the folded portion was formed in the laminate film by folding processing, the thickness of the metal layer in the horizontal portion near the folded portion was also suppressed from becoming thinner than in Comparative Example 1, in which the folded portion was formed by embossing processing. From the above results, it is presumed that in Example 1, damage to the metal layer at the folded portion of the laminate film is suppressed compared to Comparative Example 1. [Explanation of symbols]

[0073] 2, 12 upper mold 41 Left Core 42 Right Core 6. Foundation 8, 18 film 80, 180, 800 Laminate Film 11 electrodes 16 Lower mold 20 Side member 100 batteries 101 Negative electrode active material 103 Coated cathode 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 Y fusion part

Claims

1. Battery element and a laminated exterior body that encapsulates the battery element, The laminate exterior body is formed by laminating at least a resin layer and a metal layer, the battery element includes a substantially right-angled portion having an angle of 80° or more and 100° or less, and a horizontal portion having a horizontal shape; In the metal layer of the laminate exterior body that faces the substantially rectangular portion of the battery element, a thickness T1 of the metal layer at 80% or more of the metal layer satisfies the relationship of the following formula with respect to a thickness T2 of the metal layer of the laminate exterior body that faces the horizontal portion of the battery element, |T1-T2| / T2×100(%)≦10% Formula a ratio (|T3-T2| / T2×100(%)) of a difference between a thickness T3 of the metal layer at a position in the laminate exterior body that faces the horizontal portion of the battery element and that is 1 mm from a position that faces the substantially right-angled portion of the battery element and a thickness T2 of the metal layer of the laminate exterior body that faces the horizontal portion of the battery element is within 10%; Laminated battery.

2. 2. The laminated battery according to claim 1, wherein the laminated outer casing has three mountain-shaped folds and one valley-shaped fold at a position opposite the substantially rectangular portion of the battery element.

3. A battery module having a plurality of laminated type batteries stacked in the thickness direction, The battery module, wherein the laminated battery is the laminated battery according to claim 1 .

4. a battery element including a substantially right-angled portion having an angle of 80° or more and 100° or less and a horizontal portion having a horizontal shape; a laminated outer casing that encapsulates the battery element and is formed by laminating at least a resin layer and a metal layer, a folding step of forming a folding line by folding molding at a position of the laminate exterior body that faces the substantially rectangular portion of the battery element when the battery element is enclosed; an encapsulation step of encapsulating the battery element in the laminate exterior body having the folding line; and the battery element includes an electrode body and a side surface member disposed on a side surface of the electrode body, In the folding step, when forming the folding line in the laminate exterior body, the folding line is not formed at a position of the laminate exterior body facing the side member. Manufacturing method for laminated batteries.

5. In the folding process, a mold having an arc-shaped surface on a part of a surface that comes into contact with the laminate exterior body is used, 5. The method for manufacturing a laminated battery according to claim 4, wherein the arc-shaped surface contacts a position of the laminated exterior body that faces the horizontal portion of the battery element when the battery element is enclosed.

6. 5. The method for manufacturing a laminated battery according to claim 4, wherein the laminated outer casing after the encapsulation process has three mountain folds and one valley fold at a position opposite the approximately right-angled portion of the battery element.

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