Laminate type battery and manufacturing method of the laminate type battery

Abstract

To provide a laminate type battery of which the generation of wrinkle in a laminate sheet is suppressed.SOLUTION: A laminate type battery 10 includes: an electrode body 4; and a laminate sheet 2 that covers the electrode body 4, and includes a fusing part 20 in which a one end side of the laminate sheet 2 that covers the electrode body 4 and the other end side are fused. The fusing part 20 includes a step part of which a thickness in a region near from the electrode body 4 side is thinner than a thickness far from the electrode body 4 side. A ratio (LS1 / LE) of an outer peripheral length LE of the electrode body 4 and an inner peripheral length LS1 of the laminate sheet 2 coating the electrode body 4 is 1.00 or more and 1.05 or less.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a laminated battery 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 exterior 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 material. [Prior art documents] [Patent documents]

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

[0004] Conventionally, laminating devices that laminate electrodes with a laminate sheet have been used to laminate electrodes of various sizes, i.e., electrodes with variations in size. However, when laminating small-sized electrodes, it is not possible to precisely adhere the laminate sheet to the electrode, resulting in excess (i.e., sagging) in the laminate sheet, which can cause wrinkles. Wrinkled areas of the laminate sheet can become scratched or torn, which can reduce the structural durability.

[0005] The present disclosure has been made in view of the above-described circumstances, and aims to provide a laminated battery in which the occurrence of wrinkles in the laminate sheet is suppressed, and a method for manufacturing such a laminated battery. [Means for solving the problem]

[0006] <1> An electrode body; a laminate sheet covering the electrode body, a fused portion at which one end side and the other end side of the laminate sheet covering the electrode body are fused together, the fusion portion has a step portion in which the thickness of a region close to the electrode body side is thinner than the thickness of a region farther from the electrode body side, The outer periphery length L of the electrode body E and the inner periphery length L of the laminate sheet covering the electrode body. S1 Ratio to (L S1 / L E ) is 1.00 or more and 1.05 or less. <2> Said ratio (L S1 / L E ) is 1.00, <1> 2. The laminated battery according to claim 1. <3> In the step portion, the difference (t1-t2) between the thickness t1 at the thickest point in the region close to the electrode body side and the thickness t2 at the thinnest point in the region farther from the electrode body side is 10 μm or more and 150 μm or less. <1> or <2> 2. The laminated battery according to claim 1. <4> An electrode body; a laminate sheet covering the electrode body, A method for manufacturing a laminated battery having a fused portion in which one end side and the other end side of the laminate sheet covering the electrode body are fused, The fused portion is formed by two or more fusion steps performed at different positions, In the first fusion step, a region farther from the electrode body side than the region fused in the second fusion step is fused; In the second fusion process, a region closer to the electrode body side than the region fused in the first fusion process is fused, and the inner periphery length L of the laminate sheet after fusion in the first fusion process and before fusion in the second fusion process is S0 minus twice the length L2 from the end of the electrode body side of the region fused in the first fusion process to the end of the electrode body side of the region fused in the second fusion process, and the circumferential length L of the electrode body E The ratio of ((L S0 -2×L2) / L E ) is 1.00 or more and 1.05 or less. <5> the fused portion after the second fusion step has a step portion in which the thickness of a region close to the electrode body side is thinner than the thickness of a region farther from the electrode body side, In the step portion, the difference (t1-t2) between the thickness t1 at the thickest point in the region close to the electrode body side and the thickness t2 at the thinnest point in the region farther from the electrode body side is 10 μm or more and 150 μm or less. <4> A method for manufacturing the laminated battery according to claim 1. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a laminated battery in which the occurrence of wrinkles in the laminate sheet is suppressed, and a method for manufacturing the laminated battery. [Brief explanation of the drawings]

[0008] [Figure 1] 1A to 1C are schematic cross-sectional views illustrating steps of a method for manufacturing a laminated battery according to an embodiment of the present disclosure. [Figure 2] 1A to 1C are schematic cross-sectional views illustrating steps of a method for manufacturing a laminated battery according to an embodiment of the present disclosure. [Figure 3] 1A to 1C are schematic cross-sectional views illustrating steps of a method for manufacturing a laminated battery according to an embodiment of the present disclosure. [Figure 4] 1A to 1C are schematic cross-sectional views illustrating steps of a method for manufacturing a laminated battery according to an embodiment of the present disclosure. [Figure 5] 1A to 1C are schematic cross-sectional views illustrating steps of a method for manufacturing a laminated battery according to an embodiment of the present disclosure. [Figure 6] 1A and 1B are schematic cross-sectional views showing enlarged fusion sections when a laminated battery according to an embodiment of the present disclosure is manufactured, in which (A) is an enlarged cross-sectional view showing the fusion section before the first fusion process is performed, (B) is an enlarged cross-sectional view showing the fusion section after the first fusion process has been performed and before the second fusion process is performed, and (C) is an enlarged cross-sectional view showing the fusion section after the second fusion process has been performed. [Figure 7] FIG. 1 is a schematic cross-sectional view showing an example of a solid-state battery. DETAILED DESCRIPTION OF THE INVENTION

[0009] The laminated battery and its manufacturing method according to the present disclosure will be described in detail below with reference to the drawings. The drawings shown below are schematic, and the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, in this specification, when describing the arrangement of a certain member relative to another member, the term "above" or "below" simply refers to the arrangement of the other member directly above or below the certain member, unless otherwise specified. This includes both cases where a member is placed above or below another member via another member.

[0010] <Laminated battery manufacturing method> First, a method for manufacturing a laminated battery according to the present disclosure will be described with reference to the drawings. 1 to 5 are schematic cross-sectional views showing the steps of a method for manufacturing a laminated battery according to an embodiment of the present disclosure.

[0011] ·Preparation process First, as shown in Fig. 1, one laminate sheet 2 is folded to cover the electrode body 4, and then one end side and the other end side of the laminate sheet 2 are overlapped. Thereafter, by performing two fusion processes with offset positions in the first and second fusion processes described below, a fused portion 20 is formed in which one end side and the other end side of the laminate sheet 2 are fused, as shown in Fig. 5.

[0012] First fusion process In the first fusion step, a region where one end and the other end of the laminate sheet 2 are overlapped is fused, the region being farther from the electrode body 4 than the region to be fused in the second fusion step. That is, as shown in Fig. 1, fusion member 6B is placed so as to contact one side of the first fusion region, and fusion member 6A is moved from the opposite side in the direction of arrow A, thereby sandwiching the first fusion region between fusion members 6A and 6B, as shown in Fig. 2. Thereafter, fusion members 6A and 6B apply heat and pressure to laminate sheet 2, thereby fusing the first fusion region.

[0013] In this way, in the first fusion process, only the area farther from the electrode body 4 than the area to be fused in the second fusion process is fused first, thereby fixing the area on the tip side of the area that will ultimately become the fused portion 20 where one end side and the other end side of the laminate sheet 2 are fused.

[0014] Second fusion process Next, in the second fusion step, as shown in Fig. 3, a region closer to the electrode body 4 than the region fused in the first fusion step is fused. As shown in Fig. 3, fusion member 6D is placed on one side of the second fusion region, and fusion member 6C is moved from the opposite side in the direction of arrow B, thereby sandwiching the second fusion region between fusion members 6C and 6D, as shown in Fig. 4. Thereafter, the laminate sheet 2 is heated and pressurized by fusion members 6C and 6D, thereby fusing the second fusion region.

[0015] In the second fusion process, the inner periphery L of the laminate sheet 2 after fusion in the first fusion process and before fusion in the second fusion process is S0minus twice the length L2 from the end of the electrode body 4 side of the region fused in the first fusion process to the end of the electrode body 4 side of the region fused in the second fusion process, and the circumferential length L of the electrode body 4 E The ratio of ((L S0 -2×L2) / L E ) is 1.00 or more and 1.05 or less. Here, the inner periphery length L of the laminate sheet after fusion in the first fusion process and before fusion in the second fusion process S0 The length L1 refers to the shortest distance (length in the direction of winding one laminate sheet around the electrode body) of the part of the surface of the laminate sheet facing the electrode body, excluding the area fused in the first fusion process. Also, the length L2 from the electrode body side end of the area fused in the first fusion process to the electrode body side end of the area fused in the second fusion process refers to the length of the area that is not fused in the first fusion process among the areas that will eventually become the fusion part (length in the direction in which the fusion part extends from the electrode body). Also, the perimeter length L of the electrode body E This refers to the total length of the shortest distance between the four sides of a laminate sheet in the direction in which it is rolled up.

[0016] In the second fusion step, before the second fusion region of the laminate sheet 2 is sandwiched between fusion members 6C and 6D, a gap 8 exists between the electrode assembly 4 and the laminate sheet 2, as shown in Fig. 3. However, by fixing the tip side of the region that will ultimately become the fusion part in the first fusion step and sandwiching a region closer to the electrode assembly 4 than the first fusion region between fusion members 6C and 6D, the region of the laminate sheet 2 that covers the electrode assembly 4 is pulled toward the second fusion region. This allows the electrode assembly 4 and the laminate sheet 2 to be closely attached, as shown in Fig. 4, and the gap 8 between the electrode assembly 4 and the laminate sheet 2 is eliminated. The inner periphery length L of the laminate sheet 2 after the first fusion step and before the second fusion step S0 minus twice the length L2 of the region that is to be fused in the second fusion process and is not fused in the first fusion process, and the circumferential length L of the electrode body 4 E The ratio of ((LS0 -2×L2) / L E The second fusion is performed so that the axial length L of the electrode assembly 4 is 1.00 or more and 1.05 or less. This allows the laminate sheet 2 in the area covering the electrode assembly 4 to be sufficiently pulled in toward the second fusion area, effectively eliminating the gap 8 between the electrode assembly 4 and the laminate sheet 2. As a result, in the manufactured battery, the circumferential length L of the electrode assembly 4 is E and the inner periphery length L of the laminate sheet 2 covering the electrode body 4. S1 Ratio to (L S1 / L E ) can be controlled in the range of 1.00 to 1.05.

[0017] By laminating the electrode body 4 with the laminate sheet 2 through the first and second fusion processes described above, a laminated battery 10 is obtained in which the electrode body 4 and the laminate sheet 2 are well adhered to each other, as shown in Figure 5.

[0018] Conventionally, laminating devices that laminate electrodes with a laminate sheet have been used to laminate electrodes of various sizes, i.e., electrodes with variations in size. However, when laminating small-sized electrodes, it is not possible to precisely adhere the laminate sheet to the electrode, resulting in excess (i.e., sagging) in the laminate sheet, which can cause wrinkles. Wrinkled areas of the laminate sheet can become scratched or torn, which can reduce the structural durability.

[0019] In contrast, the method for manufacturing a laminated battery according to the present disclosure provides a laminated battery in which the electrode assembly and the laminated sheet are well adhered to each other, thereby suppressing the occurrence of wrinkles in the laminated sheet and achieving high structural durability.

[0020] In the present disclosure, the region fused in the second fusion step may partially overlap with the region fused in the first fusion step, as shown in Figures 3 and 4. The second fusion region and the first fusion region may not overlap, but in this case, it is preferable that the position of the end of the first fusion region on the electrode side coincides with the position of the end of the second fusion region on the opposite side from the electrode. The fusion members 6C and 6D used in the second fusion step may be the same as the fusion members 6A and 6B used in the first fusion step.

[0021] <Laminated battery> Next, the laminated battery according to the present disclosure will be described with reference to the drawings. FIG. 6 is a schematic cross-sectional view showing the fused portion when a laminated battery according to an embodiment of the present disclosure is manufactured, where (A) is an enlarged cross-sectional view showing the fused portion before the first fusion step is performed, (B) is an enlarged cross-sectional view showing the fused portion after the first fusion step has been performed and before the second fusion step is performed, and (C) is an enlarged cross-sectional view showing the fused portion after the second fusion step has been performed.

[0022] In the laminated battery according to the embodiment of the present disclosure, one end side 2A and the other end side 2B of the laminate sheet are fused together at a fused portion 20, as shown in FIG. 20 has a step portion in which the thickness N of a region closer to the electrode body side (left side in FIG. 6) is thinner than the thickness M of a region further from the electrode body side. This step portion is formed by first fusing a first fusion region X1 of a laminate sheet in which one end side 2A and the other end side 2B are overlapped as shown in FIG. 6(A), and then by second fusing a second fusion region X2 of the laminate sheet as shown in FIG. 6(B). In other words, the thickness M of the region further from the electrode body side is thicker than the region where the first fusion region X1 and the second fusion region X2 overlap, and the thickness N of the second fusion region X2 is thinner than the thickness M. Note that the thickness L of a region further from the electrode body side than the thickness M is thinner than the thickness M. As described above, the fusion portion 20 has a step portion in which the thickness N of the region closer to the electrode body side is thinner than the thickness M of the region further from the electrode body side, which means that the fusion portion is formed by two or more fusion processes performed at shifted positions, and in the first fusion process, an area farther from the electrode body side than the area fused in the second fusion process is fused, and in the second fusion process, an area closer to the electrode body side than the area fused in the first fusion process is fused.

[0023] The laminated battery according to the embodiment of the present disclosure has a circumferential length L E and the inner periphery L of the laminate sheet covering the electrode body. S1 Ratio to (L S1 / L E ) is 1.0 or more and 1.05 or less. In other words, as shown in Fig. 5, the electrode body 4 and the laminate sheet 2 are well adhered to each other, and the gap 8 between the electrode body 4 and the laminate sheet 2 is reduced. Electrode body perimeter L E This refers to the total length of the shortest distance between the four sides of a laminate sheet in the direction in which it is rolled up. Inner circumference L of the laminate sheet covering the electrode body S1 The inner perimeter L is the length of the surface of the laminate sheet that contacts the electrode body in the direction in which it is wound around the electrode body. S1When there is a gap between the laminate sheet and the electrode body, or when wrinkles occur in the area with the gap, the length of the inner peripheral surface of the laminate sheet in the gap area and the length of the inner peripheral surface of the laminate sheet in the wrinkled area are also included.

[0024] In this way, the fused portion has a step portion in which the thickness N of the region close to the electrode body side is thinner than the thickness M of the region farther from the electrode body side, and the ratio (L S1 / L E In the laminated battery according to the embodiment of the present disclosure, in which the thickness of the laminated sheet is controlled within the above range, the occurrence of wrinkles in the laminated sheet is suppressed, and high structural durability can be obtained.

[0025] In addition, the ratio (L S1 / L E ) is more preferably 1.0 or more and 1.03 or less, and is 1.0 (i.e., the circumferential length L E and the inner periphery L of the laminate sheet covering the electrode body. S1 It is more preferable that

[0026] The difference (t1-t2) between the thickness t1 at the thickest point in the region close to the electrode body and the thickness t2 at the thinnest point in the region farther from the electrode body is preferably 10 μm or more in minimum, and the upper limit is preferably 50% or less of the thickness of two laminate films (thickness at the non-welded portion).More preferably, the difference (t1-t2) is 10 μm or more and 150 μm or less.

[0027] <Battery components> Next, each component constituting the laminated battery according to the present disclosure will be described.

[0028] (1) Electrode body The electrode assembly 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.

[0029] The positive electrode active material layer contains at least a positive electrode active material. and a binder. The positive electrode active material may be, 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.

[0030] 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.

[0031] 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.)

[0032] 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 1The ratio of oxygen it occupies is 85 atomic % or more. ) composite oxide represented by (specific example is 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, 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. ) composite oxides are exemplified.

[0033] Examples of the lithium composite oxide having a crystal structure belonging to P63 - mmc include, for example, M1 x M2 y O2 (M1 represents an alkali metal (at least one of Na and K is preferable), M2 represents a transition metal (at least one selected from the group consisting of Mn, Ni, Co, and Fe is preferable), and x + y satisfies 0 < x + y ≦ 2. ) composite oxides are exemplified. <000026G> Examples of the lithium composite oxide having an O2 - type structure include, for example, Li x [Li α (Mn a Co b M c ) 1-α O2 (0.5 < x < 1.1, 0.1 < α < 0.33, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi. ) composite oxides are exemplified, and specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni<00G0070>O2 etc. are exemplified.

[0035] Further, the positive electrode preferably contains a solid electrolyte selected from the group of solid electrolytes consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte in addition to the positive electrode active material, 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 for coating at least a part of the surface of the positive electrode active material, Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≤ 1.5) [LTAF electrolyte] is preferable.

[0036] 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 a rubber-based binder and a fluoride-based binder.

[0037] 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 4-x etc. 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.

[0038] 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. <00002

[0039] It is preferable to include at least one type of solid electrolyte selected from the group of solid electrolytes consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes as the solid electrolyte.

[0040] 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. [[ID=​​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 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.

[0042] 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 )b F6 (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.

[0043] The positive electrode current collector conducts the current collection of the positive electrode active material layer. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, iron, titanium, carbon, etc., and an aluminum alloy foil or an aluminum foil is preferable. The aluminum alloy foil and the aluminum foil may be manufactured using powder. The shape of the positive electrode current collector is, for example, foil-like or mesh-like. The positive electrode current collector may have a positive electrode tab for connecting to the positive electrode current collection terminal.

[0044] 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. The negative electrode current collector may have a negative electrode tab for connecting to the negative electrode current collection terminal.

[0045] The electrode body in the present disclosure may, for example, have 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. Also, the side member may be an exterior member having no current collection function.

[0046] Examples of the material of the side member include metals such as SUS. Also, an aspect in which the side member has a coating resin layer on the surface in contact with the laminate film is included. Examples of the material of the coating resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE). The thickness of the coating resin layer is, for example, 40 μm or more and 150 μm or less.

[0047] (2) Laminate sheet An example of the laminate sheet 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 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.

[0048] (3)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.

[0049] 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. 7, and the solid electrolyte layer B may have a two-layer structure as shown in FIG. 7. FIG. 7 is a schematic cross-sectional view showing an example of a solid-state battery. The solid-state battery shown in FIG. 7 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.

[0050] 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.

[0051] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Explanation of symbols]

[0052] 2 Laminated Sheet 2A One end of the laminate sheet 2B Other end of laminate sheet 4 Electrode body 6A, 6B Fusing member 8. Gap 10 Laminated battery 20 Fusion part 101 Negative electrode active material 103 Coated cathode active material 105, 107 Conductive additives 109, 111 Binder 113 Negative electrode current collector 115 Positive electrode current collector A negative electrode active material layer B Solid electrolyte layer C positive electrode active material layer

Claims

1. An electrode body; a laminate sheet covering the electrode body; a fused portion formed by fusing one end side and the other end side of the laminate sheet covering the electrode body; The fused portion has a stepped portion in which the thickness of a region closer to the electrode body side is thinner than the thickness of a region farther from the electrode body side.

2. A laminated battery as described in claim 1, wherein the electrode body has a solid electrolyte layer.

3. The laminated battery according to claim 1, wherein the ratio (L S1 / L E ) of the outer periphery length L E of the electrode body to the inner periphery length L S1 of the laminate sheet covering the electrode body is 1.00 or more and 1.05 or less.

4. The ratio (L Ｓ１ / L Ｅ 2. The laminated battery according to claim 1, wherein the ρ is 1.

00.

5. 2. The laminated battery according to claim 1, wherein the difference (t1-t2) between the thickness t1 at the thickest point in the region close to the electrode body side and the thickness t2 at the thinnest point in the region farther from the electrode body side in the step portion is 10 μm or more and 150 μm or less.

6. An electrode body; a laminate sheet covering the electrode body; A method for manufacturing a laminated battery having a fused portion in which one end side and the other end side of the laminate sheet covering the electrode body are fused, the fused portion is formed by two or more fusion steps performed at different positions, In the first fusion step, a region farther from the electrode body side than a region to be fused in the second fusion step is fused; A method for manufacturing a laminated battery, wherein in the second fusion step, a region closer to the electrode body side than the region fused in the first fusion step is fused.

7. A method for manufacturing a laminated battery as described in Claim 6, wherein the electrode body has a solid electrolyte layer.

8. A method for manufacturing a laminated battery as described in claim 6, wherein the thickness of the region farther from the electrode body than the region where the region fused in the first fusion process and the region fused in the second fusion process overlap is defined as M, the thickness of the region fused in the first fusion process is defined as L, and the thickness of the region fused in the second fusion process is defined as N, and thickness N and thickness L are thinner than thickness M.

9. A method for manufacturing a laminated battery as described in claim 6, wherein fusion is performed in the second fusion process so that the ratio ((L S0 - 2 × L 2 ) / L E ) of the length obtained by subtracting twice the length L 2 from the end of the electrode body side of the area fused in the first fusion process to the end of the electrode body side of the area fused in the second fusion process from the inner periphery L S0 of the laminate sheet after fusion in the first fusion process and before fusion in the second fusion process, to the outer periphery L E of the electrode body, is 1.00 or more and 1.05 or less.

10. the fused portion after the second fusion step has a step portion in which the thickness of a region close to the electrode body side is thinner than the thickness of a region farther from the electrode body side, 7. The method for manufacturing a laminated battery according to claim 6, wherein the difference (t1-t2) between the thickness t1 at the thickest point in the region close to the electrode body side and the thickness t2 at the thinnest point in the region farther from the electrode body side in the step portion is 10 μm or more and 150 μm or less.

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