Battery and module

Abstract

To provide a battery in which the occurrence of a short circuit is suppressed.SOLUTION: A battery of a present disclosure, comprises: a flat-shaped electrode body that is formed by alternately laminating a positive electrode and a negative electrode through a separator; an outer casing body that houses the electrode body; a positive electrode tub that is projected from the outer casing body toward a first direction orthogonal to a thickness direction of the electrode body, and is electrically connected to the electrode body; and a negative electrode tub that is projected from the outer casing body toward the first direction or a direction on the side opposite to the first direction, and is electrically connected to the negative electrode. The outer casing body includes at least one laminated sheet. The electrode body includes a non-contact portion to which the positive electrode and the negative electrode are not in contact with the separator in both end portions in a second direction orthogonal to the thickness direction and the first direction. The outer casing body includes a welding portion to which both the laminate sheets are welded to each other via at least a part of the non-contact portion.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] 2. Description of the Related Art Lithium secondary batteries (hereinafter, also referred to as "batteries") using a non-aqueous electrolyte are used in information and communication technologies (for example, personal computers, smartphones, etc.), in-vehicle applications, power storage, and the like.

[0003] The battery has an electrode assembly in which positive electrodes and negative electrodes are alternately stacked with separators interposed therebetween. Electrode tabs are formed on the electrode assembly. The electrode tabs, through which current passes during charging and discharging of the battery, generate a large amount of heat. The separator is generally a porous film made of resin. Therefore, the portion of the separator adjacent to the electrode tab is prone to shrinkage. If the separator shrinks, the positive electrode and the negative electrode may come into contact with each other, causing a short circuit.

[0004] Patent Document 1 discloses a battery assembly 900 capable of suppressing the shrinkage of a portion of a separator adjacent to an electrode tab. The battery assembly 900 is disposed in a battery case of a battery. As shown in FIG. 6 and FIG. 7, the battery assembly 900 has a plurality of electrode plates 910 (positive or negative electrodes), a separator 920, and an insulation reinforcement portion 930 for suppressing thermal shrinkage of the separator 920. The separator 920 is interposed between each of the plurality of electrode plates 910. An electrode tab 911 is formed on each of the plurality of electrode plates 910. The separator 920 has an excess outer periphery that is larger than the outer periphery of the electrode plate 910. The insulation reinforcement portion 930 is formed in a portion of the excess outer periphery of the separator 920 adjacent to the electrode tab 911. The insulation reinforcement portion 930 has a width W. The insulation reinforcement portion 930 connects the outer periphery of the electrode plate 910 and the excess outer periphery of the separator 920 to each other. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2018 / 0145376 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Patent Document 1 does not disclose anything about the relationship between the battery assembly 900 and the battery case. If the battery assembly 900 is simply housed in a battery case, there is a risk that both edge portions E920 (see FIG. 6) of the separator 920 will shrink when the battery generates abnormal heat, causing a short circuit.

[0007] The present disclosure has been made in consideration of the above circumstances. An object of one embodiment of the present disclosure is to provide a battery and a module in which the occurrence of short circuits is suppressed. [Means for solving the problem]

[0008] Means for solving the above problems include the following embodiments.

[0009] <1> The battery according to the first aspect of the present disclosure comprises: a flat electrode assembly in which positive electrodes and negative electrodes are alternately stacked with separators interposed therebetween; An exterior body that houses the electrode assembly; a positive electrode tab protruding from the exterior body in a first direction perpendicular to a thickness direction of the electrode body and electrically connected to the positive electrode; a negative electrode tab that protrudes from the exterior body toward the first direction or a direction opposite to the first direction and is electrically connected to the negative electrode; Equipped with The exterior body has at least one laminate sheet, the electrode body has uncontacted portions at both edges in a second direction perpendicular to the thickness direction and the first direction, where the positive electrode and the negative electrode are not in contact with a separator, The battery has an exterior body having a welded portion where the laminate sheets are welded to each other via at least a part of the non-contact portion.

[0010] In the present disclosure, a "laminate sheet" refers to a sheet having at least a metal layer, a first resin layer laminated on one main surface of the metal layer, and a second resin layer laminated on the other main surface of the metal layer. In this disclosure, when the exterior body has one laminate sheet, "the laminate sheets" refers to the first and second parts of the single laminate sheet. When the exterior body has multiple laminate sheets, "the laminate sheets" refers to the first laminate sheet part and the second laminate sheet part.

[0011] In the first embodiment, the exterior body has a welded portion where the laminate sheets are welded together via at least a part of the non-contact portion. That is, the portions of the separator corresponding to both edge portions in the second direction of the electrode body (hereinafter also referred to as "both edge portions") are sandwiched between the laminate sheets and fixed to the welded portion. Therefore, the both edge portions of the separator in the first embodiment are less likely to shrink when the battery generates abnormal heat than when the both edge portions of the separator are not sandwiched between the laminate sheets. As a result, the occurrence of a short circuit is suppressed in the battery in the first embodiment.

[0012] <2> The battery according to the second aspect of the present disclosure comprises: the positive electrode comprises a plurality of positive electrode sheets; the negative electrode includes a plurality of negative electrode sheets, the separator includes a plurality of separator sheets; the electrode body is formed by stacking the positive electrode sheets and the negative electrode sheets alternately with the separator sheets interposed therebetween along the thickness direction, The uncontacted portion extends along the first direction. <1> The battery is as described in the above.

[0013] The battery of the second embodiment is a so-called stacked type battery.

[0014] <3> The battery according to the third aspect of the present disclosure comprises: When the exterior body is viewed in the thickness direction, a ratio of an area of ​​the non-contact portion in the welded portion (hereinafter, also referred to as "SR10A") to an area of ​​the welded portion (hereinafter, also referred to as "SR20") (hereinafter, also referred to as "ratio (SR10A / SR20)") is 10% or more. <1> or <2> The battery is as described in the above.

[0015] As a result, both edge portions of the separator of the third embodiment are more strongly fixed to the welded portion than when the ratio (SR10A / SR20) is less than 10%. Therefore, both edge portions of the separator of the third embodiment are less likely to shrink when the battery generates abnormal heat. As a result, the occurrence of short circuits is further suppressed in the battery of the third embodiment.

[0016] <4> The battery according to the fourth aspect of the present disclosure comprises: a surface of the non-contact portion (hereinafter also referred to as a "first portion") in the welded portion of the separator is rougher than a surface of a portion (hereinafter also referred to as a "second portion") of the separator that is different from the non-contact portion in the welded portion; <1> ~ <3> 1. The battery according to claim 1 ,

[0017] In the present disclosure, "rough surface" means a surface having a large surface roughness value. The surface roughness can be measured by arithmetic mean roughness (Ra) measured in accordance with JIS B 0601:2013.

[0018] As a result, the contact area of ​​the first portion with the welded portion in the fourth embodiment is larger than when the surface of the first portion is not rougher than the surface of the second portion. As a result, both edge portions of the separator in the fourth embodiment are more strongly fixed to the welded portion. As a result, the occurrence of a short circuit is further suppressed in the battery in the fourth embodiment.

[0019] <5> The battery according to the fifth aspect of the present disclosure comprises: a thickness of the uncontacted portion in the welded portion of the separator is thinner than a thickness of a portion of the separator other than the uncontacted portion in the welded portion; <1> ~ <4> 1. The battery according to claim 1 ,

[0020] As a result, the contact area of ​​the first portion with the welded portion in the fifth embodiment is larger than when the thickness of the first portion is not greater than the thickness of the second portion. As a result, both edge portions of the separator in the fifth embodiment are more strongly fixed to the welded portion. As a result, the occurrence of a short circuit is further suppressed in the battery in the fifth embodiment.

[0021] <6> The module of the sixth aspect of the present disclosure comprises: The above <1> ~ <5> a plurality of batteries according to any one of claims 1 to 4; a case housing the plurality of batteries; The module includes:

[0022] As a result, in the module of the sixth aspect, the occurrence of a short circuit is suppressed. Effect of the Invention

[0023] According to the present disclosure, a battery and a module are provided in which the occurrence of short circuits is suppressed. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a front view of a battery according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view of the battery shown in FIG. 1 taken along line II-II. [Diagram 3] FIG. 3 is a perspective view of a module according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a top view of a module according to an embodiment of the present disclosure with the case lid removed. [Diagram 5] FIG. 5 is a schematic diagram of a vehicle equipped with a module according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a front view of a battery assembly disposed within a battery case of a conventional battery. [Figure 7] FIG. 7 is a side view of a battery assembly disposed within a battery case of a conventional battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are merely illustrative of the embodiments, and are not intended to limit the scope of the embodiments. In the present disclosure, combinations of two or more preferred embodiments are more preferred embodiments. In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the numerical ranges described in this disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.

[0026] Hereinafter, embodiments of the battery and module of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0027] (1)Battery 1, a battery 1 according to an embodiment of the present disclosure includes a flat electrode assembly 10, an exterior body 20, a positive electrode tab 30, a negative electrode tab 40, and a nonaqueous electrolyte (not shown). The battery 1 is a rectangular parallelepiped.

[0028] In this embodiment, one side of the short side of the main surface of the battery 1 is defined as the X-axis positive direction, and the opposite side is defined as the X-axis negative direction. The positive electrode tab 30 side of the long side of the main surface of the battery 1 is defined as the Y-axis positive direction, and the opposite side is defined as the Y-axis negative direction. One side of the thickness direction of the battery 1 is defined as the Z-axis positive direction, and the opposite side is defined as the Z-axis negative direction. The X-axis, Y-axis, and Z-axis are mutually orthogonal. The Y-axis is an example of a first direction. The X-axis is an example of a second direction. The Z-axis is an example of a thickness direction of the electrode body. Note that these directions do not limit the orientation of the battery of the present disclosure during use.

[0029] The exterior body 20 accommodates the electrode assembly 10 and a non-aqueous electrolyte. The exterior body 20 has two welded portions R20. The positive electrode tab 30 protrudes from the exterior body 20 in the positive direction of the Y axis. The negative electrode tab 40 protrudes from the exterior body 20 in the negative direction of the Y axis.

[0030] The length L1 of the battery 1 in the X-axis direction (see FIG. 1) is, for example, 80 mm to 110 mm. The length L2 of the battery 1 in the Y-axis direction (see FIG. 1) is, for example, 530 mm to 600 mm. The length L3 of the battery 1 in the Z-axis direction (see FIG. 2) is, for example, 7.0 mm to 9.0 mm.

[0031] (1.1) Electrode body The electrode body 10 has a laminated structure. As shown in FIG. 2, the electrode body 10 includes a plurality of positive electrode sheets 11, a plurality of negative electrode sheets 12, and a plurality of separator sheets 13. The electrode body 10 is formed by alternately laminating the positive electrode sheets 11 and the negative electrode sheets 12 with the separator sheets 13 interposed therebetween. The positive electrode sheet 11 is an example of a positive electrode. The negative electrode sheet 12 is an example of a negative electrode. The separator sheet 13 is an example of a separator.

[0032] The number of each of the positive electrode sheets 11, the negative electrode sheets 12, and the separator sheets 13 is not particularly limited and is appropriately selected depending on the application of the battery 1, etc.

[0033] 1, the electrode body 10 has a pair of uncontacted portions R10A and an electrode portion R10B. The pair of uncontacted portions R10A are located at both ends in the X-axis direction of the electrode body 10. The electrode portion R10B is located between the pair of uncontacted portions R10A in the X-axis direction.

[0034] The electrode portion R10B is a portion that generates electricity. In the electrode portion R10B, positive electrode sheets 11 and negative electrode sheets 12 are alternately laminated with separator sheets 13 interposed therebetween. In this embodiment, the outermost layer of the electrode portion R10B is formed of the separator sheet 13. The length L4 (see FIG. 1) of the electrode portion R10B in the X-axis direction is, for example, 60 mm to 105 mm. The length L5 (see FIG. 1) of the electrode portion R10B in the Y-axis direction is, for example, 500 mm to 520 mm.

[0035] The uncontacted portion R10A is a portion that does not generate electricity. The uncontacted portion R10A is a portion of the electrode body 10 where the positive electrode sheet 11 and the negative electrode sheet 12 are not in contact with the separator sheet 13. In other words, the uncontacted portion R10A is composed of only a plurality of separator sheets 13. The uncontacted portion R10A extends along the Y-axis direction. The length L6 of the uncontacted portion R10A in the X-axis direction (see FIG. 1) is, for example, 1 mm to 20 mm. The length of the uncontacted portion R10A in the Y-axis direction is the same as the length L5 of the electrode portion R10B in the Y-axis direction (see FIG. 1).

[0036] (1.1.1) Positive electrode sheet The positive electrode sheet 11 has a positive electrode current collector (e.g., aluminum foil, etc.) and a positive electrode active material layer supported by the positive electrode current collector. The positive electrode active material layer contains a positive electrode active material. The positive electrode active material releases lithium ions to the non-aqueous electrolyte or absorbs lithium ions from the non-aqueous electrolyte. The positive electrode active material may be a known positive electrode active material (e.g., LiNiO2, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The positive electrode active material layer may further contain a known conductive material (for example, carbon black, etc.), trilithium phosphate, and a known binder (for example, polyvinylidene fluoride, etc.).

[0037] (1.1.2) Negative electrode sheet The negative electrode sheet 12 has a negative electrode current collector (e.g., copper foil, etc.) and a negative electrode active material layer supported by the negative electrode current collector. The negative electrode active material layer contains a negative electrode active material. The negative electrode active material absorbs lithium ions, which are charge carriers, from a non-aqueous electrolyte solution during charging and discharging, and releases them to the non-aqueous electrolyte solution. The negative electrode active material may be a known negative electrode active material (artificial graphite, lithium alloy (e.g., LiXM, where M is C, Si, Sn, Sb, Al, Mg, Ti, Bi, Ge, Pb, P, etc., and X is a natural number), etc.). The negative electrode active material layer may further contain a known binder (e.g., styrene-butadiene copolymer, etc.).

[0038] (1.1.3) Separator Sheet The separator sheet 13 electrically insulates the positive electrode from the negative electrode, and provides a path for lithium ions to move between the positive electrode active material layer and the negative electrode active material layer. The separator sheet 13 may be a porous membrane or the like. Examples of the material for the porous membrane include polyethylene and polypropylene. The separator sheet 13 may have a single-layer structure or a multi-layer structure.

[0039] The surface of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 is rougher than the surface of a portion of the separator sheet 13 other than the uncontacted portion R10A in the welded portion R20 (i.e., the electrode portion R10B). The welded portion R20 is usually formed by heat pressing. When the heat pressing is performed, creep occurs in the uncontacted portion R10A of the separator sheet 13. "Creep" refers to a phenomenon in which strain increases over time for a constant stress when an external force is applied to an object. In other words, the surface of the uncontacted portion R10A of the separator sheet 13 is more stretched than the surface before the heat pressing (i.e., a surface equivalent to the surface of the electrode portion R10B). Therefore, the surface of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 becomes rougher than the surface of the electrode portion R10B.

[0040] The thickness of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 is thinner than the thickness of a portion of the separator sheet 13 other than the uncontacted portion R10A in the welded portion R20 (i.e., the electrode portion R10B). The welded portion R20 is usually formed by heat pressing. Therefore, the thickness of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 is thinner than the thickness of the electrode portion R10B.

[0041] (1.2) Exterior body The exterior body 20 covers the electrode assembly 10 and seals the electrode assembly 10 and the non-aqueous electrolyte together with the positive electrode tab 30 and the negative electrode tab 40.

[0042] In this embodiment, the exterior body 20 has one laminate sheet 200. One laminate sheet 200 has two embossed portions 210 (see FIG. 2) for accommodating the electrode body 10. The exterior body 20 is obtained by folding one laminate sheet 200 and sandwiching and sealing the electrode body 10 between the two embossed portions 210.

[0043] The exterior body 20 has two welded portions R20. In this embodiment, in the welded portion R20, the laminate sheets 200 are welded to each other via the entire non-contact portion R10A.

[0044] In this embodiment, when the outer casing 20 is viewed from the Z-axis direction, the ratio of the area SR10A (see Figure 1) of the uncontacted portion R10A in the welded portion R20 to the area SR20 (see Figure 1) of the welded portion R20 (hereinafter also referred to as the "ratio (SR10A / SR20)") is 10% or more.

[0045] (1.2.1) Laminate sheet 2, the laminate sheet 200 has a metal layer 201, an inner resin layer 202, and an outer resin layer 203. The inner resin layer 202 is laminated on a surface S201A of the metal layer 201 facing the electrode body 10. The outer resin layer 203 is laminated on a surface S201B of the metal layer 201 opposite the electrode body 10 side.

[0046] Metal layer 201 blocks the passage of gas (for example, moisture, air, etc.) between the outside and the inside of battery 1. Metal layer 201 is made of a metal (for example, aluminum, etc.).

[0047] The inner resin layer 202 constitutes the welded portion R20. In addition, the inner resin layer 202 electrically insulates the electrode body 10, the positive electrode tab 30, and the negative electrode tab 40 from the metal layer 201. The inner resin layer 202 may contain a thermoplastic resin. Examples of the thermoplastic resin include olefin-based resins (e.g., polypropylene, polyethylene, etc.), polyvinyl chloride, polyvinylidene chloride, polystyrene-based resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, polyester-based resins, poly(meth)acrylic-based resins, polyvinyl alcohol, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polyacetal-based resins, fluorine-based resins, polysulfone-based resins, polyphenylene sulfide resins, and polyketone-based resins.

[0048] In particular, the thermoplastic resin preferably contains a resin compatible with the separator sheet 13. This improves the adhesion between the welded portion R20 and the separator sheet 13. "Having compatibility" means that the first resin and the second resin are mixed together without being separated in an atmosphere in which the first resin and the second resin are melted. The resin compatible with the separator sheet 13 is appropriately selected according to the material of the separator sheet 13. When the separator sheet 13 contains polyethylene, the inner resin layer 202 preferably contains polyethylene. When the separator sheet 13 contains polypropylene, the inner resin layer 202 preferably contains polypropylene.

[0049] The inner resin layer 202 may contain additives as necessary, such as heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, release agents, and antistatic agents.

[0050] The outer resin layer 203 improves the durability of the laminate sheet 200. The outer resin layer 203 may contain a thermoplastic resin. The thermoplastic resin of the outer resin layer 203 is not particularly limited, and may be the same as the thermoplastic resin exemplified for the inner resin layer 202. The thermoplastic resin of the outer resin layer 203 may be the same as or different from the thermoplastic resin of the inner resin layer 202. The outer resin layer 203 may contain a compounding agent as necessary. Examples of the compounding agent include a heat stabilizer, an antioxidant, a pigment, a weathering agent, a flame retardant, a plasticizer, a dispersant, a lubricant, a release agent, and an antistatic agent.

[0051] (1.3) Positive electrode tab The positive electrode tab 30 is electrically connected to a plurality of positive electrode sheets 11 .

[0052] The positive electrode current collector has a positive electrode lead portion extending in the positive direction of the Y axis. No positive electrode active material layer is formed on the positive electrode lead portion. The positive electrode tab 30 may be composed of only a plurality of positive electrode lead portions. The positive electrode tab 30 may include a plurality of positive electrode lead portions and a positive electrode lead connected to the plurality of positive electrode lead portions. The length L7 (see FIG. 1) of the positive electrode tab 30 in the X axis direction is, for example, 40 mm to 50 mm.

[0053] (1.4) Negative electrode tab The negative electrode tab 40 is electrically connected to the multiple negative electrode sheets 12 .

[0054] The negative electrode current collector has a negative electrode lead portion extending in the negative direction of the Y axis. No negative electrode active material layer is formed on the negative electrode lead portion. The negative electrode tab 40 may be composed of only a plurality of negative electrode lead portions. The negative electrode tab 40 may include a plurality of negative electrode lead portions and a negative electrode lead connected to the plurality of negative electrode lead portions. The length L7 (see FIG. 1) of the negative electrode tab 40 in the X axis direction is, for example, 40 mm to 50 mm.

[0055] (1.5) Non-aqueous electrolyte The battery 1 includes a non-aqueous electrolyte. The non-aqueous electrolyte is accommodated in an exterior body 20 together with the electrode assembly 10. The non-aqueous electrolyte may be a non-aqueous solvent (e.g., ethyl carbonate) in which a supporting salt (e.g., LiPF6, etc.) is dissolved or dispersed as an electrolyte. The non-aqueous electrolyte may contain various additives (e.g., lithium bis(oxalato)borate, etc.).

[0056] (1.6) Application The use of the battery 1 is not particularly limited, and examples thereof include a power source for vehicles, a power source for information processing devices (for example, personal computers, smartphones, etc.), a power source for storing electricity, and the like.

[0057] (1.7) Effects 1 and 2, the battery 1 includes an electrode assembly 10, an exterior body 20, a positive electrode tab 30, and a negative electrode tab 40. The exterior body 20 has one laminate sheet 200. The electrode assembly 10 has uncontacted portions R10A at both edges in the X-axis direction. The exterior body 20 has a welded portion R20 via the uncontacted portions R10A. That is, the portions of the separator sheet 13 corresponding to both edge portions in the X-axis direction of the electrode body 10 (hereinafter also referred to as "both edge portions") are sandwiched between the laminate sheets 200 and fixed to the welded portion R20. Therefore, when the battery 1 generates abnormal heat, the both edge portions of the separator sheet 13 are less likely to shrink than if the both edge portions of the separator sheet 13 were not sandwiched between the laminate sheets 200. As a result, the occurrence of short circuits in the battery 1 is suppressed.

[0058] 1 and 2, in the battery 1, the electrode body 10 includes a plurality of positive electrode sheets 11, a plurality of negative electrode sheets 12, and a plurality of separator sheets 13. The electrode body 10 is formed by stacking the positive electrode sheets 11 and the negative electrode sheets 12 alternately along the Z-axis direction with the separator sheets 13 interposed therebetween. The uncontacted portion R10A extends along the Y-axis direction. In other words, the battery 1 is a so-called stacked type battery.

[0059] As described with reference to FIGS. 1 and 2, in the battery 1, when the exterior body 20 is viewed from the Z-axis direction, the ratio (SR10A / SR20) is 10% or more. As a result, both edge portions in the X-axis direction of the separator sheet 13 are fixed to the welded portion R20 more strongly than when the ratio (SR10A / SR20) is less than 10%. Therefore, both edge portions in the X direction of the separator sheet 13 are less likely to shrink when the battery 1 generates abnormal heat. As a result, the occurrence of short circuits in the battery 1 is further suppressed.

[0060] As described with reference to Figures 1 and 2, in battery 1, the surface of uncontacted portion R10A in welded portion R20 of separator sheet 13 is rougher than the surface of a portion of separator sheet 13 other than uncontacted portion R10A in welded portion R20 (i.e., electrode portion R10B). As a result, the contact area between the uncontacted portion R10A of the separator sheet 13 and the welded portion R20 is larger than when the surface of the uncontacted portion R10A is not rougher than the surface of the electrode portion R10B. As a result, both edge portions of the separator sheet 13 are more strongly fixed to the welded portion R20. As a result, the occurrence of a short circuit in the battery 1 is further suppressed.

[0061] As explained with reference to Figures 1 and 2, in battery 1, the thickness of uncontacted portion R10A in welded portion R20 of separator sheet 13 is thinner than the thickness of a portion of separator sheet 13 other than uncontacted portion R10A in welded portion R20 (i.e., electrode portion R10B). As a result, the contact area between the uncontacted portion R10A of the separator sheet 13 and the welded portion R20 is larger than when the thickness of the uncontacted portion R10A is not thinner than the thickness of the electrode portion R10B. As a result, both edge portions of the separator sheet 13 are more strongly fixed to the welded portion R20. As a result, the occurrence of a short circuit in the battery 1 is further suppressed.

[0062] (2) Module 3 and 4, a module 2 according to an embodiment of the present disclosure includes a plurality of batteries 1 and a case 50. The case 50 houses the plurality of batteries 1.

[0063] The module 2 is a rectangular parallelepiped object as shown in Fig. 2. The length L10 of the module 2 in the Y-axis direction is, for example, 350 mm to 600 mm. The length L11 of the module 2 in the Z-axis direction is, for example, 150 mm to 250 mm. The length L12 of the module 2 in the X-axis direction is, for example, 80 mm to 110 mm.

[0064] A pair of voltage terminals 61 and a connector 62 are provided at both ends of the module 2 in the Y-axis direction. A flexible printed circuit board 63, which will be described later, is connected to the connector 62. Bus bars (not shown) are welded to both ends of the module 2 in the Y-axis direction.

[0065] The case 50 has a case body 51 and a case lid 52. The case 50 is made of an aluminum alloy. For example, the case 50 is formed by joining aluminum die-casting to both ends of an aluminum alloy extrusion material by laser welding or the like.

[0066] As shown in Fig. 3, a plurality of batteries 1 are housed in an array inside the module 2. In this embodiment, 24 batteries 1 are arranged along the Z-axis direction. Adjacent batteries 1 are adhered to each other.

[0067] A flexible printed circuit board (FPC: Flexible Printed Circuit) 63 is disposed on the battery 1. The flexible printed circuit board 63 is formed in a strip shape with the X-axis direction as the longitudinal direction, and a thermistor 64 is provided on each of both ends of the flexible printed circuit board 63. In the module 2, the thermistor 64 is not adhered to the battery 1, and is pressed towards the battery 1 by the case lid 52.

[0068] One or more cushioning materials (not shown) are housed inside the module 2. For example, the cushioning materials are elastically deformable thin plate-like members, and are arranged between adjacent batteries 1 with the arrangement direction of the batteries 1 being the thickness direction. In this embodiment, as an example, cushioning materials are arranged at both ends of the module 2 in the longitudinal direction and in the central portion in the longitudinal direction.

[0069] (2.2) Usage example The module 2 is suitable for use as a battery pack 310 that is a power source for a vehicle 300. As shown in Fig. 5, the vehicle 300 is a battery electric vehicle (BEV) in which a battery pack 310 is mounted under the floor.

[0070] In this embodiment, the positive X-axis direction, the positive Z-axis direction, and the positive Y-axis direction respectively indicate the upper side in the vehicle vertical direction, the front side in the vehicle longitudinal direction, and the left side in the vehicle width direction.

[0071] In the vehicle 300 of this embodiment, as an example, a DC / DC converter 301, an electric compressor 302, and a PTC (Positive Temperature Coefficient) heater 303 are arranged on the vehicle front side of a battery pack 310. In addition, a motor 304, a gear box 305, an inverter 306, and a charger 307 are arranged on the vehicle rear side of the battery pack 310.

[0072] The direct current output from the battery pack 310 is adjusted in voltage by a DC / DC converter 301, and then supplied to an electric compressor 302, a PTC heater 303, an inverter 306, etc. In addition, power is supplied to a motor 304 via the inverter 306, causing the rear wheels to rotate and causing the vehicle 300 to run.

[0073] A charging port 308 is provided on the right side at the rear of vehicle 300, and by connecting a charging plug of an external charging device (not shown) to charging port 308, electricity can be stored in battery pack 310 via charger 307.

[0074] The arrangement and structure of each component constituting the vehicle 300 are not limited to the above-mentioned configuration. For example, the present invention may be applied to a hybrid vehicle (HV: Hybrid Vehicle) equipped with an engine or a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle). In this embodiment, the vehicle is a rear-wheel drive vehicle in which the motor 304 is mounted at the rear of the vehicle, but the present invention is not limited to this. The vehicle may be a front-wheel drive vehicle in which the motor 304 is mounted at the front of the vehicle, or a pair of motors 304 may be mounted at the front and rear of the vehicle. Furthermore, the vehicle may be equipped with an in-wheel motor on each wheel.

[0075] The battery pack 310 includes a plurality of modules 2. In this embodiment, ten modules 2 are provided. Specifically, five modules 2 are arranged in the vehicle front-rear direction on the right side of the vehicle 300, and five modules 2 are arranged in the vehicle front-rear direction on the left side of the vehicle 300. Each of the plurality of modules 2 is electrically connected to each other.

[0076] (2.3) Effects As described with reference to FIGS. 1 to 4, the module 2 includes a plurality of batteries 1 and a case 50. As a result, the occurrence of a short circuit in module 2 is suppressed.

[0077] (3) Variations In this embodiment, the structure of the electrode assembly 10 is a laminated type, but the present disclosure is not limited to this. The structure of the electrode assembly of the present disclosure may be a wound type.

[0078] In this embodiment, the ratio (SR10A / SR20) is 10% or more, but the present disclosure is not limited thereto. The ratio (SR10A / SR20) in the present disclosure may be less than 10%.

[0079] In this embodiment, the surface of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 is rougher than the surface of the electrode portion R10B, but the present disclosure is not limited thereto. In the present disclosure, the surface of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 does not have to be rougher than the surface of the electrode portion R10B.

[0080] In this embodiment, the thickness of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 is thinner than the thickness of the electrode portion R10B, but the present disclosure is not limited thereto. In the present disclosure, the thickness of the uncontacted portion R10A in the welded portion R20 of the separator sheet 13 does not have to be thinner than the thickness of the electrode portion R10B.

[0081] In this embodiment, the exterior body 20 is composed of one laminate sheet 200, but the present disclosure is not limited to this. The exterior body 20 may be composed of a plurality of laminate sheets 200.

[0082] In this embodiment, the laminate sheets 200 are welded to each other at the welded portion R20 through the entire non-contact portion R10A, but the present disclosure is not limited thereto. The laminate sheets 200 may be welded to each other at the welded portion R20 through a part of the non-contact portion R10A.

[0083] In this embodiment, the exterior body 20 has a double cup embossed structure, but the present disclosure is not limited thereto. The exterior body 20 may have a single cup embossed structure. [Explanation of symbols]

[0084] 1 battery, 2 module, 10 electrode body, 11 positive electrode sheet, 12 negative electrode sheet, 13 separator sheet, 20 exterior body, 30 positive electrode tab, 40 negative electrode tab, 50 case, 51 case body, 52 case cover, 61 voltage terminal, 62 connector, 63 flexible printed circuit board, 64 thermistor, 200 laminate sheet, 201 metal layer, 202 inner resin layer, 203 outer resin layer, 210 embossed portion, 300 vehicle, 301 converter, 302 electric compressor, 303 heater, 304 motor, 305 gear box, 306 inverter, 307 charger, 308 charging port, 310 battery pack, R10A non-contact portion, R10B electrode portion, R20 welded portion

Claims

1. a flat electrode assembly in which positive electrodes and negative electrodes are alternately stacked with separators interposed therebetween; An exterior body that houses the electrode assembly; a positive electrode tab protruding from the exterior body in a first direction perpendicular to a thickness direction of the electrode body and electrically connected to the positive electrode; a negative electrode tab protruding from the exterior body in the first direction or in a direction opposite to the first direction and electrically connected to the negative electrode; Equipped with The exterior body has at least one laminate sheet, the electrode body has uncontacted portions at both edges in a second direction perpendicular to the thickness direction and the first direction, where the positive electrode and the negative electrode are not in contact with a separator, The battery, wherein the exterior body has a welded portion where the laminate sheets are welded to each other via at least a part of the uncontacted portion.

2. the positive electrode comprises a plurality of positive electrode sheets; the negative electrode includes a plurality of negative electrode sheets, the separator includes a plurality of separator sheets; the electrode body is formed by stacking the positive electrode sheets and the negative electrode sheets alternately with the separator sheets interposed therebetween along the thickness direction, The battery of claim 1 , wherein the uncontacted portion extends along the first direction.

3. The battery according to claim 1 , wherein when the exterior body is viewed in the thickness direction, a ratio of an area of ​​the uncontacted portion in the welded portion to an area of ​​the welded portion is 10% or more.

4. 2. The battery of claim 1, wherein a surface of the uncontacted portion in the welded portion of the separator is rougher than a surface of a portion of the separator other than the uncontacted portion in the welded portion.

5. The battery according to claim 1 , wherein a thickness of the uncontacted portion in the welded portion of the separator is thinner than a thickness of a portion of the separator other than the uncontacted portion in the welded portion.

6. A plurality of batteries according to any one of claims 1 to 5; a case housing the plurality of batteries; A module comprising:

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