Laminated battery and method for manufacturing laminated 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 Art

[0002] A battery such as a lithium-ion secondary battery generally includes an electrode body 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 body is sealed, for example, in an internal space surrounded by an exterior material. Patent Document 1 discloses a lithium polymer secondary battery including an electrode assembly, an exterior material surrounding the outside of the electrode assembly, and first and second covers for sealing the exterior material, wherein a first electrode terminal and a second electrode terminal are respectively drawn out to the outside through the first cover and the second cover. Further, Patent Document 1 describes a laminate film as an exterior material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in a laminating apparatus for laminating an electrode with a laminate sheet, electrodes of various sizes, that is, electrodes with size variations, have been laminated. However, when laminating an electrode with a small size, the laminate sheet and the electrode cannot be accurately adhered, and an excess portion (i.e., slack) is generated in the laminate sheet, and wrinkles may occur in the excess portion. In the portion where wrinkles occur in the laminate sheet, scratches and tears may occur, and the structural durability is likely to decrease.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a laminated battery in which the generation of wrinkles in a laminated sheet is suppressed, and a method for manufacturing the laminated battery.

Means for Solving the Problems

[0006] <1> An electrode body, a laminated sheet covering the electrode body, and having, a fused portion where one end side and the other end side of the laminated sheet covering the electrode body are fused, the fused portion having a stepped portion where 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, the outer peripheral length L of the electrode body E and the inner peripheral length L of the laminated sheet covering the electrode body S1 and the ratio (L S1 / L E ) is 1.00 or more and 1.05 or less, a laminated battery. <2> The laminated battery according to <1>, wherein the ratio (L S1 / L E ) is 1.00. <3> In the stepped portion, the difference (t1 - t2) between the thickness t1 at the thickest portion in the region closer to the electrode body side and the thickness t2 at the thinnest portion in the region farther from the electrode body side is 10 μm or more and 150 μm or less, the laminated battery according to <1> or <2>. <4> An electrode body, a laminated sheet covering the electrode body, and having, a method for manufacturing a laminated battery having a fused portion where one end side and the other end side of the laminated sheet covering the electrode body are fused, the fused portion is formed by two or more fusing steps performed with a shift in position, in the first fusing step, a region farther from the electrode body side than the region to be fused in the second fusing step is fused, In the second fusion step, a region closer to the electrode body than the region fused in the first fusion step is fused, and the inner peripheral length L of the laminate sheet after fusion in the first fusion step and before fusion in the second fusion step S0 is such that the length obtained by subtracting twice the value of the length L2 from the end on the electrode body side of the region fused in the first fusion step to the end on the electrode body side of the region fused in the second fusion step, and the outer peripheral length L E of the electrode body S0 results in a ratio ((L E - 2×L2) / L <5> of 1.00 or more and 1.05 or less, and the fusion in the second fusion step is performed. A method for manufacturing a laminated battery After the second fusion step, the fused portion has a stepped portion where the thickness of the region closer to the electrode body is thinner than the thickness of the region farther from the electrode body, In the stepped portion, the difference (t1 - t2) between the thickness t1 at the thickest point in the region closer to the electrode body and the thickness t2 at the thinnest point in the region farther from the electrode body is 10 μm or more and 150 μm or less. The method for manufacturing a laminated battery according to <4>

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

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the laminated battery and its manufacturing method in the present disclosure will be described in detail with reference to the drawings. Each of the drawings shown below is schematically illustrated, and the size and shape of each part are exaggerated as appropriate for easy understanding. Also, in this specification, when expressing the manner of arranging one member with respect to another member, when simply described as "above" or "below", unless otherwise specified, it includes both the case where another member is arranged directly above or directly below so as to be in contact with a certain member, and the case where another member is arranged above or below a certain member via another member.

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

[0011] · Preparation step First, as shown in FIG. 1, an electrode body 4 is covered by folding a single laminate sheet 2, and then one end side and the other end side of the laminate sheet 2 are overlapped. Thereafter, by performing two fusions with a shift in position through the first fusion step and the second fusion step shown below, as shown in FIG. 5, a fusion part 20 in which one end side and the other end side of the laminate sheet 2 are fused is formed.

[0012] ·First fusion step In the first fusion step, among the regions where one end side and the other end side of the laminate sheet 2 are overlapped, the region farther from the electrode body 4 than the region to be fused in the second fusion step is fused. That is, as shown in FIG. 1, a fusion member 6B is arranged so as to be in contact with one side of the first fusion region, and the fusion member 6A is moved in the direction of arrow A from the opposite side, whereby the first fusion region is sandwiched between the fusion members 6A and 6B as shown in FIG. 2. Thereafter, by heating and pressurizing the laminate sheet 2 with the fusion members 6A and 6B, the first fusion region is fused.

[0013] In this way, by first fusing only the region farther from the electrode body 4 than the region to be fused in the second fusion step through the first fusion step, the tip-side region is fixed among the regions that finally become the fusion part 20 where one end side and the other end side of the laminate sheet 2 are fused.

[0014] ·Second fusion step Next, in the second fusion step, as shown in FIG. 3, the region closer to the electrode body 4 than the region fused in the first fusion step is fused. As shown in FIG. 3, a fusion member 6D is applied to one side of the second fusion region, and the fusion member 6C is moved in the direction of arrow B from the opposite side, whereby the second fusion region is sandwiched between the fusion members 6C and 6D as shown in FIG. 4. Thereafter, by heating and pressurizing the laminate sheet 2 with the fusion members 6C and 6D, the second fusion region is fused.

[0015] Note that in the second fusion step, the inner peripheral length L of the laminate sheet 2 after the fusion in the first fusion step and before the fusion in the second fusion step S0From the length of the electrode body 4 side end of the region fused in the first fusion step to the length of the electrode body 4 side end of the region fused in the second fusion step, subtract twice the value of the length L2, and then calculate the ratio with the outer peripheral length L of the electrode body 4 E ((L S0 - 2×L2) / L E ) is made to be 1.00 or more and 1.05 or less, and then fusion is performed. Here, the inner peripheral length L of the laminate sheet after fusion in the first fusion step and before fusion in the second fusion step S0 refers to the length of the shortest distance of the portion excluding the region fused in the first fusion step on the electrode body side surface of the laminate sheet (the length in the direction of winding a single laminate sheet around the electrode body). Also, the length L2 from the electrode body side end of the region fused in the first fusion step to the electrode body side end of the region fused in the second fusion step refers to the length of the region not fused in the first fusion step among the regions that finally become the fusion part (the length in the direction in which the fusion part extends from the electrode body). Further, the outer peripheral length L of the electrode body E refers to the total length of the shortest distances of the four surfaces in the direction of winding a single laminate sheet.

[0016] In the second fusion step, until the second fusion region in the laminate sheet 2 is sandwiched by the fusion members 6C and 6D, as shown in FIG. 3, there is a gap 8 between the electrode body 4 and the laminate sheet 2. However, with the state where the tip side of the region that finally becomes the fusion part is fixed by the first fusion step, by sandwiching the region closer to the electrode body 4 side than the first fusion region with the fusion members 6C and 6D, the laminate sheet 2 in the region covering the electrode body 4 is pulled in the direction of the second fusion region. As a result, as shown in FIG. 4, the electrode body 4 and the laminate sheet 2 can be brought into close contact, and the gap 8 between the electrode body 4 and the laminate sheet 2 is eliminated. Note that from the inner peripheral length L of the laminate sheet 2 after fusion in the first fusion step and before fusion in the second fusion step S0 subtract twice the value of the length L2 of the region not fused in the first fusion step among the regions fused in the second fusion step, and then calculate the ratio with the outer peripheral length L of the electrode body 4 E ((LS0 -2×L2) / L E ) is 1.00 or more and 1.05 or less, the second heat fusion is performed. As a result, the laminate sheet 2 in the region covering the electrode body 4 can be sufficiently pulled into the direction of the second heat fusion region, and the gap 8 between the electrode body 4 and the laminate sheet 2 can be favorably eliminated. As a result, in the manufactured battery, the outer peripheral length L of the electrode body 4 E and the inner peripheral length L of the laminate sheet 2 covering the electrode body 4 S1 and the ratio (L S1 / L E ) can be controlled within a range of 1.00 or more and 1.05 or less.

[0017] By laminating the electrode body 4 with the laminate sheet 2 through the first and second heat fusion steps shown above, as shown in FIG. 5, a laminated battery 10 in which the electrode body 4 and the laminate sheet 2 are favorably adhered to each other can be obtained.

[0018] Conventionally, in a laminating device for laminating an electrode with a laminate sheet, electrodes of various sizes, that is, electrodes with size variations, have been laminated. However, when laminating an electrode with a small size, the laminate sheet and the electrode cannot be accurately adhered to each other, and an excess portion (that is, slack) is generated in the laminate sheet, and wrinkles may occur in the excess portion. In the portion where wrinkles occur in the laminate sheet, scratches or tears may occur, and the structural durability is likely to decrease.

[0019] On the other hand, according to the method for manufacturing a laminated battery according to the present disclosure, a laminated battery in which the electrode body and the laminate sheet are favorably adhered to each other can be obtained. Therefore, the occurrence of wrinkles in the laminate sheet is suppressed, and high structural durability can be obtained.

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

[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 a fused portion when the laminated battery according to the embodiment of the present disclosure is manufactured. (A) is an enlarged cross-sectional view showing the fused portion before the first fusing step is performed, (B) is an enlarged cross-sectional view showing the fused portion after the first fusing step is performed and before the second fusing step is performed, and (C) is an enlarged cross-sectional view showing the fused portion after the second fusing step is performed.

[0022] As shown in FIG. 6(C), in the laminate type battery according to an embodiment of the present disclosure, one end side 2A and the other end side 2B of the laminate sheet are fused at the fusion part 20. And the fusion part 20 has a stepped part where the thickness N of the region closer to the electrode body side (the left side in FIG. 6) is thinner than the thickness M of the region farther from the electrode body side. This stepped part is formed by first performing the first fusion on the first fusion region X1 in the laminate sheet where the one end side 2A and the other end side 2B are overlapped as shown in FIG. 6(A), and then performing the second fusion on the second fusion region X2 in the laminate sheet as shown in FIG. 6(B). That is, the thickness M of the region farther 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 the region farther from the electrode body side than the thickness M is thinner than the thickness M. As described above, the fact that the fusion part 20 has a stepped part where the thickness N of the region closer to the electrode body side is thinner than the thickness M of the region farther from the electrode body side means that the formation of the fusion part is performed by two or more fusion steps with the positions shifted, and in the first fusion step, the region farther from the electrode body side than the region fused in the second fusion step is fused, and in the second fusion step, the region closer to the electrode body side than the region fused in the first fusion step is fused, which indicates that it is formed.

[0023] And the laminate type battery according to an embodiment of the present disclosure has an outer peripheral length L of the electrode body E and an inner peripheral length L of the laminate sheet covering the electrode body S1 The ratio (L S1 / L E ) is 1.0 or more and 1.05 or less. In other words, as shown in FIG. 5, it means that the electrode body 4 and the laminate sheet 2 are in good contact, and the gap 8 between the electrode body 4 and the laminate sheet 2 is reduced. The outer peripheral length L of the electrode body E refers to the total length of the shortest distances of the four surfaces in the direction of winding a single laminate sheet. The inner peripheral length L of the laminate sheet covering the electrode body S1It refers to the length of a single laminate sheet on the surface in contact with the electrode body in the direction of winding around the electrode body. Note that the inner peripheral length L S1 When the laminate sheet has a gap with the electrode body, or when wrinkles occur in the portion having the gap, the length of the inner peripheral side surface of the laminate sheet in the gap portion and the length of the inner peripheral side surface of the laminate sheet in the portion where wrinkles occur are also included in L

[0024] In this way, the fusion part has a stepped part where the thickness N of the region closer 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 ) is controlled within the above range. The laminate battery according to the embodiment of the present disclosure can suppress the generation of wrinkles in the laminate sheet and obtain high structural durability.

[0025] Note that the ratio (L S1 / L E ) is more preferably 1.0 or more and 1.03 or less, and more preferably 1.0 (that is, the outer peripheral length L E of the electrode body is equal to the inner peripheral length L S1 of the laminate sheet covering the electrode body).

[0026] The size of the step in the stepped part is preferably such that the lower limit value of the difference (t1 - t2) between the thickness t1 at the thickest part in the region closer to the electrode body side and the thickness t2 at the thinnest part in the region farther from the electrode body side is 10 μm or more, and the upper limit value is 50% or less of the thickness of two laminate films (the thickness at a location other than the fusion part). Further, the difference (t1 - t2) is more preferably 10 μm or more and 150 μm or less.

[0027] <Members of the battery> Next, each member constituting the laminate battery according to the present disclosure will be described.

[0028] (1) Electrode body The electrode body usually has a positive current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative current collector in this order in the thickness direction.

[0029] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. The shape of the positive electrode active material is, for example, particulate. Examples of the positive electrode active material include oxide active materials. Also, sulfur (S) may be used as the positive electrode active material.

[0030] Preferably, the positive electrode active material contains a lithium composite oxide. The lithium composite oxide may contain at least one selected from the group consisting of F, Cl, N, S, Br, and I. Also, the lithium composite oxide may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc (also referred to as P63mc and P6 / mmc). Further, the main arrangement of transition metal, oxygen, and lithium in the lithium composite oxide may be an O2-type structure.

[0031] Examples of the lithium composite oxide having a crystal structure belonging to R-3m include, for example, Li x Me y O α X β (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, satisfying 0.5 ≦ x ≦ 1.5, 0.5 ≦ y ≦ 1.0, 1 ≦ α < 2, and 0 < β ≦ 1). Compounds represented thereby are included.

[0032] Examples of the lithium composite oxide having a crystal structure belonging to Immm include, for example, Li x1 M 1 A 1 2 (satisfying 1.5 ≦ x1 ≦ 2.3, and M 1 includes at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, and A1 contains at least oxygen, and A 1 the ratio of oxygen in it is 85 atomic % or more. The composite oxide represented by ) (specific example: Li2NiO2), Li x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0 ≦ x2 ≦ 0.5, 0 ≦ y ≦ 0.3, and at least one of x2 and y is not 0. M 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. A2 represents at least one selected from the group consisting of F, Cl, Br, S, and P.). Examples of the composite oxide include those represented by

[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 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 of the composite oxide represented by

[0034] 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). Examples of the composite oxide represented by 0.744 [Li 0.145 Mn 0.625 Co0.115 Ni 0.115 Examples include O2 etc.

[0035] In addition, the positive electrode preferably contains a solid electrolyte selected from the group of solid electrolytes consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte in addition to the positive electrode active material. An embodiment 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.

[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 etc. The shape of the negative electrode active material is, for example, particulate or foil-like. Regarding the conductive material, electrolyte, and binder, the above-described content is the same.

[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. Preferably, the electrolyte layer is a solid electrolyte layer. The electrolyte layer may have a separator.

[0039] 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.

[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.

[0041] 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 electrolytes, perovskite-type solid electrolytes, NASICON-type solid electrolytes, Li-P-O-based solid electrolytes, Li-B-O-based solid electrolytes, and the like. Examples of the garnet-type solid electrolyte include, for example, Li7La3Zr2O 12 、Li 7-x La3(Zr 2-x Nb x )O 12 (0 ≦ x ≦ 2), Li5La3Nb2O 12 and the like. Examples of the perovskite-type solid electrolyte include, for example, (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, and the like. Examples of the NASICON-type solid electrolyte include, for example, Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, and the like. 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, and the like.

[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 Alx ) 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 preferred. The aluminum alloy foil and the aluminum foil may be manufactured using powder. The shape of the positive electrode current collector is, for example, foil-shaped or mesh-shaped. The positive electrode current collector may have a positive electrode tab for connection 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, and nickel. Examples of the shape of the negative electrode current collector include foil-shaped and mesh-shaped. The negative electrode current collector may have a negative electrode tab for connection 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 of the electrode body. The side member is not particularly limited as long as it is a member disposed on the side surface of the electrode body, but 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 exemplified. 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 The laminate sheet in the present disclosure includes, for example, a laminate film. The laminate film has at least a structure having a resin layer and a metal layer, and has, for example, a structure provided with a fusion resin layer (thermal fusion layer) on one surface of the metal layer (the inner surface side where the fusion part is formed). Further, the laminate film may have a fusion resin layer (thermal fusion layer), a metal layer, and a protective resin layer in this order along the thickness direction. Examples of the material of the fusion resin layer (thermal fusion layer) include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of the material of the metal layer include aluminum, aluminum alloy, and stainless steel. Examples of the material of the protective resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the fusion resin layer (thermal fusion layer) is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the protective resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the entire laminate film is, for example, 70 μm or more and 220 μm or less.

[0048] (3) Battery The battery in the present disclosure is typically a lithium-ion secondary battery, and a solid battery is preferred. The solid battery includes a so-called all-solid battery using an inorganic solid electrolyte as an electrolyte.

[0049] The structure of the solid battery has a laminated structure of a positive electrode / solid electrolyte layer / 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, for example, have a cross-sectional structure as 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 the 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 contains a negative electrode active material 101, a conductive assistant 105, and a binder 109. The positive electrode active material layer C contains a coated positive electrode active material 103, a conductive assistant 107, and a binder 111, and the surface of the positive electrode active material of the coated positive electrode active material 103 is coated with an LTAF electrolyte or a LiNbO3 electrolyte. Alternatively, the solid-state battery may be configured by sealing the laminated end face (side face) of the laminated structure of the positive electrode / solid electrolyte layer / negative electrode with resin. The current collector of the electrode may have a configuration in which a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer is disposed on the surface.

[0050] Examples of the applications of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline vehicles, and diesel vehicles. In particular, it is preferably used as a driving power source for HEVs, PHEVs, or BEVs. Further, the battery in the present disclosure may be used as a power source for moving bodies other than vehicles (e.g., railways, ships, airplanes), and may also be used as a power source for electric products such as information processing devices.

[0051] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are examples, and any configuration that has a configuration substantially the same as the technical idea described in the claims of the present disclosure and exhibits the same operational effects is included in the technical scope of the present disclosure.

Description of Reference Numerals

[0052] 2 Laminated Sheet 2A One End Side of the Laminated Sheet 2B The Other End Side of the Laminated Sheet 4 Electrode Body 6A and 6B Fusing Members 8 Gap 10 Laminate-Type Battery 20 Fusing Portion 101 Negative Electrode Active Material 103 Coated Positive Electrode Active Material 105 and 107 Conductive Auxiliary Agent 109 and 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 including a solid electrolyte layer, and a single laminate sheet covering the electrode body, having a fused portion where one end side and the other end side of the single laminate sheet covering the electrode body are fused, wherein the fused portion has a stepped portion where 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, The outer peripheral length L of the electrode body Ｅ and the inner peripheral length L of the laminate sheet covering the electrode body Ｓ１ The ratio (L Ｓ１ / L Ｅ ) is 1.00 or more and 1.05 or less, a laminated battery.

2. The ratio (L Ｓ１ / L Ｅ ) is 1.00, and the laminated battery according to claim 1.

3. In the stepped portion, the difference (t1 - t2) between the thickness t1 at the thickest point in the region closer 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. The laminate type battery according to Claim 1 or Claim 2.

4. An electrode body including a solid electrolyte layer, and a single laminate sheet covering the electrode body, A method for manufacturing a laminate type battery having a fused portion where one end side and the other end side of the single laminate sheet covering the electrode body are fused, wherein the fused portion is formed by two or more fusing steps performed with a shift in position, In the first fusing step, a region farther from the electrode body side than the region to be fused in the second fusing step is fused, In the second fusing step, a region closer to the electrode body side than the region fused in the first fusing step is fused, and the inner peripheral length L of the laminate sheet after fusing in the first fusing step and before fusing in the second fusing step Ｓ０ From the end on the electrode body side of the region fused in the first fusing step to the end on the electrode body side of the region fused in the second fusing step, the length L ２ Subtract twice the value of, and the outer peripheral length L of the electrode body Ｅ The ratio ((L Ｓ０ - 2 × L ２ ) / L Ｅ ) is 1.00 or more and 1.05 or less, and the fusing in the second fusing step is performed. A method for manufacturing a laminated battery

5. After the second fusing step, the fused portion has a stepped portion where 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, In the stepped portion, the difference (t1 - t2) between the thickness t1 at the thickest point in the region closer 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. The method for manufacturing a laminate type battery according to Claim 4.

Images