Battery

Abstract

To provide a battery that suppresses a short circuit caused by contact between a metal layer and a terminal.SOLUTION: A battery includes an electrode body, a terminal 20 electrically connected to the electrode body, a laminate film 30 covering the entire surface of the electrode body and a portion of the surface of the terminal 20 and having at least a metal layer 34, and a welded resin layer 36 as a resin layer interposed between the terminal 20 and the metal layer 34, and the welded resin layer 36 contains insulating particles 50A.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to batteries. [Background technology]

[0002] Batteries such as lithium ion secondary batteries typically include an electrode assembly having a current collector, a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer. The electrode assembly is sealed in an internal space surrounded by, for example, an exterior material. For example, Patent Document 1 discloses a laminated energy storage element in which an electrode assembly, in which sheet-like positive and negative electrodes are stacked with a separator interposed between them, is sealed together with an electrolyte solution within an outer casing made of a laminate film formed into a flat bag shape, and flat electrode terminal plates for the positive and negative electrodes connected to the positive and negative electrodes, respectively, have electrode terminal portions extending from predetermined edges of the outer casing, and the outer casing is formed by laminating the laminate films facing each other with the same outer shape and welding them to each other at peripheral regions surrounding the flat regions, and the laminate film has insulating resin layers formed on both the front and back sides of a metal foil base material, and an end face of the base material is exposed at the predetermined edges of the outer casing, and the peripheral regions are welded via a tab film in a region along the predetermined edges, and the tab film protrudes outward from the outer casing at a portion of the predetermined edges and has a deformed portion formed in a shape that covers both the front and back sides of the base ends of the electrode terminal portions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6796417 Summary of the Invention [Problem to be solved by the invention]

[0004] In the past, when sealing the electrode body and terminals of a battery with a laminate film, the resin layer interposed between the terminal and the metal layer of the laminate film melts and becomes liquid. If an excessive load is applied to a part of the laminate film at this time, the liquid resin flows from the loaded part, causing contact between the metal layer and the terminal, which can result in a short circuit.

[0005] The present disclosure has been made in view of the above circumstances, and aims to provide a battery that suppresses short circuits caused by contact between a metal layer and a terminal. [Means for solving the problem]

[0006] <1> An electrode body; a terminal electrically connected to the electrode body; a laminate film having at least a metal layer and covering the entire surface of the electrode body and a portion of the surface of the terminal; a resin layer interposed between the terminal and the metal layer, The battery, wherein the resin layer contains insulating particles. <2> As the resin layer, the laminate film has a welding resin layer on the terminal side surface of the metal layer, and the welding resin layer contains the insulating particles. <1> The battery described in <3> The resin layer includes a welding resin film interposed between the terminal and the laminate film, and the welding resin film contains the insulating particles. <1> or <2> The battery described in [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a battery that suppresses short circuits caused by contact between a metal layer and a terminal. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view illustrating a battery according to an embodiment of the present disclosure. [Figure 2]FIG. 2 is a schematic cross-sectional view showing the cross section XX in FIG. [Figure 3] 3 is an enlarged cross-sectional view showing the terminal, the tab film, and the laminate film in FIG. 2. FIG. [Figure 4] 3 is an enlarged cross-sectional view showing a state in which an excessive load is applied to a part of the terminal, tab film, and laminate film in FIG. 2. FIG. [Figure 5] FIG. 2 is an enlarged cross-sectional view showing a terminal, a tab film, and a laminate film of a battery according to another embodiment of the present disclosure. [Figure 6] FIG. 1 is an enlarged cross-sectional view showing a terminal, a tab film, and a laminate film in a conventional battery. DETAILED DESCRIPTION OF THE INVENTION

[0009] The battery according to the present disclosure will be described in detail below with reference to the drawings. The drawings are schematic diagrams, and the size and shape of each part are appropriately exaggerated for ease of understanding.

[0010] <Battery> First embodiment First, a battery according to an embodiment (first embodiment) of the present disclosure will be described. Fig. 1 is a schematic perspective view illustrating a battery according to the present disclosure. Fig. 2 is a schematic cross-sectional view showing the XX cross section in Fig. 1. The battery 100 shown in FIG. 1 is surrounded by a laminate film 30. An electrode assembly is enclosed within the laminate film 30, and the entire surface of the electrode assembly is covered by the laminate film 30. Terminals 20 are provided at one end and the other end of the electrode assembly to be electrically connected to the electrode assembly. As shown in FIGS. 1 and 2, the terminal 20 has a portion covered by the laminate film 30, and a portion exposed at each of the one end and the other end. The laminate film 30 is, for example, a single film, and this single laminate film 30 is folded to cover the electrode assembly and the terminal 20. As shown in FIG. 2, the laminate film 30 has its ends overlapped and welded to form a welded portion Y. A tab film 40, which serves as a weldable resin film, is interposed between the terminal 20 and the laminate film 30.

[0011] Fig. 3 is an enlarged cross-sectional view showing the terminal 20, tab film 40, and laminate film 30 in Fig. 2. The laminate film 30 has, in order from the terminal 20 side, a welding resin layer 36, a metal layer 34, and a protective layer 32. In other words, the battery shown in Fig. 3 has the tab film 40 and welding resin layer 36 as resin layers interposed between the terminal 20 and the metal layer 34. The welding resin layer 36 contains insulating particles 50A.

[0012] Here, a conventional battery will be described. 6 is an enlarged cross-sectional view showing the terminal, tab film, and laminate film of a conventional battery. The conventional battery has an electrode body (not shown), a terminal 200, a laminate film 300 covering the electrode body and terminal 200, and a tab film 400 interposed between the terminal 200 and the laminate film 300. The laminate film 300 has, in order from the terminal 200 side, a welding resin layer 360, a metal layer 340, and a protective layer 320. Note that the tab film 400 and the welding resin layer 360, which are resin layers interposed between the terminal 200 and the metal layer 340, do not contain insulating particles.

[0013] In conventional batteries, when the surface of the terminal 200 is sealed with the laminate film 300, the tab film 400 and the welding resin layer 360, which serve as resin layers, melt and become liquid. If an excessive load is applied to a portion of the laminate film 300, the liquid resin flows from the load-applied area, causing contact between the metal layer 340 of the laminate film 300 and the terminal 200, resulting in a short circuit, as shown in FIG. 6 . Furthermore, if the terminal 200 has even a slight protrusion (so-called burr), even a slight flow of the liquid resin can easily cause a short circuit. Furthermore, if the heating temperature during sealing with the laminate film 300 becomes too high and the viscosity of the molten resin drops too much, the resin easily flows, making a short circuit more likely. For these reasons, even if an attempt is made to apply a load evenly to avoid excessive load being applied to a portion of the laminate film 300 during sealing, it is difficult to prevent a short circuit due to contact between the metal layer 340 and the terminal 200.

[0014] In contrast, the battery shown in Fig. 3 contains insulating particles 50A in the welded resin layer 36. Therefore, even if an excessive load is applied to a portion of the laminate film 30 and the liquefied resin flows from the loaded area, the insulating particles 50A are interposed between the metal layer 34 and the terminal 20 in the laminate film 30, as shown in Fig. 4. This prevents contact between the metal layer 34 and the terminal 20, and suppresses short-circuiting between the metal layer 34 and the terminal 20.

[0015] Furthermore, the inclusion of insulating particles 50A prevents the thickness of the welding resin layer 36 after sealing from becoming smaller than the particle diameter of the insulating particles 50A. This allows the thickness of the welding resin layer 36 to be uniform, and also allows the thickness of the laminate film 30 as a whole to be uniform. Here, the welding portion Y shown in FIG. 1 may be folded to improve the structural efficiency of the battery 100. In this case, since the thickness of the entire laminate film 30 is uniform, the occurrence of defective folding locations is suppressed, and good folding properties are obtained.

[0016] Modifications 2 and 3 show an embodiment in which the tab film 40 is provided between the laminate film 30 and the terminal 20, but the present invention is not limited to this. That is, the laminate film 30 may be in direct contact with the terminal 20 without providing the tab film 40.

[0017] 1 shows an embodiment in which the electrode body and terminal 20 are covered with one laminate film 30, but this is not limited thereto, and the electrode body and terminal may be sealed with multiple laminate films. For example, when sealing the electrode body and terminal with two laminate films, the entire surface of the electrode body and part of the surface of the terminal can be covered with the two laminate films from one side and the other side in the thickness direction of the electrode body, and the ends of the two laminate films can be welded together to achieve sealing.

[0018] In a battery in which two laminate films cover the electrode assembly and terminals from one side and the other side in the thickness direction of the electrode assembly and the edges of the two laminate films are welded together, the inclusion of insulating particles in the welded resin layer of the laminate films can suppress the occurrence of short circuits throughout the battery. This is because if one of the two laminate films is short-circuited to the positive electrode of the electrode assembly and the other laminate film is short-circuited to the negative electrode, and if the two laminate films are also short-circuited together, an undesirable situation occurs in which the entire battery is short-circuited. However, the inclusion of insulating particles in the welded resin layer of the two laminate films suppresses short circuits between the two laminate films, thereby suppressing the occurrence of short circuits throughout the battery.

[0019] Second embodiment Next, a battery according to another embodiment (second embodiment) of the present disclosure will be described.

[0020] FIG. 5 is an enlarged cross-sectional view showing a terminal, a tab film, and a laminate film of a battery according to another embodiment of the present disclosure. The battery shown in FIG. 5 has an electrode body (not shown), a terminal 20, a laminate film 30 covering the electrode body and terminal 20, and a tab film 40 interposed between the terminal 20 and the laminate film 30. The laminate film 30 has, in order from the terminal 20 side, a welding resin layer 36, a metal layer 34, and a protective layer 32. In other words, the battery shown in FIG. 5 has the tab film 40 and the welding resin layer 36 as resin layers interposed between the terminal 20 and the metal layer 34. The tab film 40 contains insulating particles 50B.

[0021] 5 contains insulating particles 50B in tab film 40, so even if an excessive load is applied to a portion of laminate film 30 and the liquefied resin flows from the loaded portion, insulating particles 50B are interposed between metal layer 34 and terminal 20 in laminate film 30. This prevents contact between metal layer 34 and terminal 20, and suppresses short-circuiting between metal layer 34 and terminal 20.

[0022] In addition, in the battery shown in Figure 5, the tab film 40 provided around the terminal 20 contains insulating particles 50B, so the amount of insulating particles can be reduced compared to when insulating particles are contained in the welded resin layer 36 in the laminate film 30 that covers part of the surface of the terminal 20 and the entire surface of the electrode body.

[0023] <Battery components> Next, each component constituting the battery of the present disclosure will be described.

[0024] Laminating film The laminate film of the present disclosure preferably has at least a metal layer and further has a welding resin layer on the terminal-side surface of the metal layer. The welding resin layer corresponds to a resin layer interposed between the terminal and the metal layer. The laminate film may also have a protective layer on the metal layer on the side opposite the terminal. Examples of materials for the welded resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of materials for the protective layer include polyethylene terephthalate (PET) and nylon. The thickness of the weldable resin layer is, for example, preferably 20 μm to 100 μm, more preferably 20 μm to 60 μm, and even more preferably 40 μm to 60 μm. The thickness of the metal layer is, for example, 30 μm to 60 μm. The thickness of the protective layer is, for example, 20 μm to 60 μm. The thickness of the entire laminate film is, for example, 70 μm to 220 μm.

[0025] Tab film The battery of the present disclosure preferably has a welding resin film (so-called tab film) interposed between the terminal and the laminate film. The welding resin film corresponds to the resin layer interposed between the terminal and the metal layer. The welding resin film is provided so as to cover a portion of the surface of the terminal and be interposed between the terminal and the laminate film. Examples of materials for the welding resin film include olefin resins such as polypropylene (PP), polyethylene (PE), etc. The thickness of the welding resin film is preferably, for example, from 20 μm to 100 μm, more preferably from 20 μm to 60 μm, and even more preferably from 40 μm to 60 μm.

[0026] The thickness of the resin layer interposed between the terminal and the metal layer and containing insulating particles (e.g., a welded resin film, a welded resin layer in a laminate film, etc.) is preferably 20 μm or more and 100 μm or less, more preferably 20 μm or more and 60 μm or less, and even more preferably 40 μm or more and 60 μm or less.

[0027] Here, the thickness of each layer is the average value of measurements taken at 10 arbitrarily selected points.

[0028] Insulating particles The insulating particles are contained in a resin layer (for example, a welded resin film or a welded resin layer in a laminate film) that is interposed between the terminal and the metal layer. The term "insulating" in insulating particles refers to the property of not conducting electricity, specifically, a material with a volume resistivity of 10 14 This means that the volume resistivity of a material is Ω·cm or more. The volume resistivity of a material can be measured using the method specified in JIS C2141:1992.

[0029] The insulating particles include, for example, inorganic particles and metal oxide particles, and it is preferable to include one or more types of particles selected from these groups. The shape of the insulating particles is not particularly limited, but from the viewpoint of efficiently suppressing short circuits between the metal layer and the terminal, it is preferable that the insulating particles have a spherical shape.

[0030] From the viewpoint of efficiently suppressing short circuits between the metal layer and the terminal, the insulating particles preferably have an average particle size of 30 μm or more and 50 μm or less, and more preferably 35 μm or more and 45 μm or less. Here, the average particle diameter of the insulating particles is determined by taking an SEM image of the cross section of the resin layer containing the insulating particles, measuring the maximum diameter of 50 randomly selected insulating particles, and calculating the average value.

[0031] The average spacing between the insulating particles contained in the resin layer is preferably 100 μm or more and 1000 μm or less, and more preferably 200 μm or more and 500 μm or less, from the viewpoint of efficiently suppressing short circuits between the metal layer and the terminal. Here, the average spacing of insulating particles is determined by taking an SEM image of the cross section of the resin layer containing insulating particles, measuring the spacing (i.e., the shortest distance) between 50 arbitrarily selected pairs of adjacent insulating particles, and calculating the average value.

[0032] For example, it is preferable that the resin layer interposed between the terminal and the metal layer contains insulating particles and has an average thickness of 20 μm or more and 60 μm or less, an average particle diameter of the insulating particles of 30 μm or more and 50 μm or less, and an average distance between the insulating particles of 100 μm or more and 1000 μm or less.

[0033] ·Electrode body The electrode assembly in the present disclosure typically has a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector, in this order in the thickness direction.

[0034] 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.

[0035] 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.

[0036] 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.)

[0037] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 2(1.5≦x1≦2.3, M 1 contains at least one selected from the group consisting of Ni, Co, Mn, Cu and Fe, and A 1 contains at least oxygen, and A 1 The oxygen ratio is 85 atomic % or more. x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0≦x2≦0.5, 0≦y≦0.3, and at least one of x2 and y is not 0, and M 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.

[0038] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include M1 x M2 yO2 (where M1 represents an alkali metal (preferably at least one of Na and K), M2 represents a transition metal (preferably at least one selected from the group consisting of Mn, Ni, Co, and Fe), and 0 < x + y ≦ 2). Examples include composite oxides represented by this formula.

[0039] As the lithium composite oxide having an O2-type structure, 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 this formula, and specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 and the like.

[0040] 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 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.

[0041] Examples of conductive materials 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. The liquid electrolyte (electrolytic solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. Examples of binders include rubber-based binders and fluoride-based binders.

[0042] 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 Li4Ti5O 12 The negative electrode active material may be in the form of particles or foil, for example. The conductive material, electrolyte, and binder are the same as those described above.

[0043] 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.

[0044] The solid electrolyte preferably contains at least one solid electrolyte species selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes.

[0045] As a sulfide solid electrolyte, it is preferable to contain sulfur (S) as the main component of the anion element, and more preferably, for example, to contain 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.

[0046] As an 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(Zr2-x Nb x )O 12 (0 ≦ x ≦ 2), Li5La3Nb2O 12 etc. Examples of perovskite-type solid electrolytes include, for example, (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, etc. Examples of NASICON-type solid electrolytes include, for example, Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, etc. Examples of Li-P-O-based solid electrolytes include Li3PO4, LIPON (a compound in which a part of O in Li3PO4 is replaced by N), and examples of Li-B-O-based solid electrolytes include Li3BO3, a compound in which a part of O in Li3BO3 is replaced by C, etc.

[0047] As a 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 preferred. Among Li 6-3z Y z X6, Li3YX6 (X represents Cl or Br) is more preferred in terms of excellent lithium ion conductivity, and further, Li3YCl6 is preferred. 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 oxidative decomposition of the sulfide solid electrolyte, etc.

[0048] The positive electrode current collector collects current from the positive electrode active material layer. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, iron, titanium, and carbon, and aluminum alloy foil or aluminum foil is preferred. The aluminum alloy foil and aluminum foil may be manufactured using powder. The positive electrode current collector may have a foil or mesh shape, for example. The positive electrode current collector may have a positive electrode tab for connection to a positive electrode current collector terminal.

[0049] The negative electrode current collector collects current from the negative electrode active material layer. Examples of materials for 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 and mesh. The negative electrode current collector may have a negative electrode tab for connection to a negative electrode current collector terminal.

[0050] Terminals The terminals in the present disclosure are disposed on the side surfaces of the electrode body. Examples of the terminals include current collecting terminals. The current collecting terminals refer to terminals having current collecting portions at least in part. The current collecting portions are electrically connected to tabs on the electrode body, for example. The current collecting terminals may be entirely current collecting portions, or may only be partially current collecting portions. Examples of materials for the terminals include metals such as SUS.

[0051] ·battery The battery in the present disclosure is typically a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferred that the battery be used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0052] 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.

[0053] Here, the effects of the battery according to the present disclosure were confirmed through experiments.

[0054] In Experimental Example 1, a battery having the configuration shown in Fig. 3 was prepared. That is, a battery was prepared that had an electrode body, a terminal 20, a laminate film 30 covering the electrode body and terminal 20, and a tab film 40 interposed between the terminal 20 and the laminate film 30, and the laminate film 30 had, in order from the terminal 20 side, a welding resin layer 36, a metal layer 34, and a protective layer 32. The welding resin layer 36 contained insulating particles 50A.

[0055] In Experimental Example 2, a battery having the configuration shown in Fig. 5 was prepared. That is, a battery having the same layer configuration as the battery shown in Fig. 3 was prepared, but containing insulating particles in the tab film 40 instead of the welding resin layer 36.

[0056] On the other hand, as a comparative example, a battery having the configuration shown in Fig. 6 was prepared. That is, a battery having the same layer configuration as the battery shown in Fig. 3 was prepared, but containing no insulating particles in either the welding resin layer 36 or the tab film 40.

[0057] For the batteries of Experimental Example 1, Experimental Example 2, and Comparative Example, we checked whether or not a short circuit occurred due to contact between the terminal and the metal layer when welding (sealing) the laminate film around the terminal. We also measured the thickness of the area where the tab film and laminate film were welded around the terminal (especially if a short circuit occurred, the thickness at the area where the short circuit occurred, the seal thickness). The results are shown in Table 1.

[0058] [Table 1]

[0059] As shown in Table 1, in Experimental Examples 1 and 2, in which insulating particles are contained in the adhesive resin layer 36 or tab film, which is a resin layer interposed between the terminal and the metal layer, the occurrence of short circuits is suppressed. [Explanation of symbols]

[0060] 20, 200 terminals 30, 300 Laminate Film 32, 320 protective layer 34, 340 metal layer 36, 360 welding resin layer 40, 400 tab film 50A, 50B insulating particles 100 batteries

Claims

1. An electrode body; a terminal electrically connected to the electrode body; a laminate film having at least a metal layer and a welding resin layer on the terminal-side surface of the metal layer, the laminate film covering the entire surface of the electrode body and a part of the surface of the terminal; a welding resin film interposed between the terminal and the laminate film, The battery, wherein the welding resin layer and the welding resin film contain insulating particles.

2. The battery according to claim 1 , wherein the terminals include a first terminal arranged at one end side of the electrode body in the first direction, and a second terminal arranged at the other end side of the electrode body in the first direction.

3. The laminate film has a welded portion where inner surfaces of the laminate film are overlapped and welded together, a cross-sectional shape of each of the first terminal and the second terminal when the battery is cut along a plane perpendicular to the first direction is a rectangular shape including a pair of long sides extending in the second direction and a pair of short sides extending in a third direction perpendicular to the second direction, 3. The battery according to claim 2, wherein the length of the first terminal in the second direction and the length of the second terminal in the second direction are each 0.5 to 1.0 times the length of the electrode body in the second direction.

4. The laminate film has a welded portion where inner surfaces of the laminate film are overlapped and welded together, a cross-sectional shape of each of the first terminal and the second terminal when the battery is cut along a plane perpendicular to the first direction is a rectangular shape including a pair of long sides extending in the second direction and a pair of short sides extending in a third direction perpendicular to the second direction, 3. The battery of claim 2, wherein when the battery is viewed from the first direction, the welded portions have four first welded portions extending from each of the four corners of the first terminal toward the opposite side of the first terminal, and four second welded portions extending from each of the four corners of the second terminal toward the opposite side of the second terminal.

Images