Battery

Abstract

To provide a battery capable of improving a volume efficiency of a module while discharging an internal gas to an external part in the case where an internal pressure is excessively increased.SOLUTION: A battery of the present disclosure comprises: an electrode body; and a laminate outer casing body that houses the electrode body into an internal part. The laminate outer casing body includes a mechanism. The mechanism can be switched to a close state for closing the internal part, and an open state of opening the internal part to the external part of the laminate outer casing body. The mechanism is switched from the close state to the open state when a pressure of the internal part of the laminate outer casing body exceeds a threshold value. The mechanism is positioned in a virtual region surrounded by a pair of first virtual straight lines containing a pair of first sides extended in a first direction in a plan view and a pair of second virtual straight lines containing a pair of second sides extended in a second direction. In a third direction that is orthogonal to the first and second directions, a length of the mechanism is shorter than the length of the laminate outer casing body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery.

Background Art

[0002] Patent Document 1 specifically discloses a power storage device 900 (hereinafter also referred to as "battery 900") shown in FIG. 6. The battery 900 includes a container 910 (hereinafter also referred to as "laminated exterior body 910"), a power storage device element 920 (hereinafter also referred to as "electrode body 920"), a pair of tabs 930, a tab film 940, a valve device 950, and a heat-sealing film 960.

[0003] The laminated exterior body 910 houses the electrode body 920. The laminated exterior body 910 has an internal space R910A and a peripheral seal portion R910B. The laminated exterior body 910 is rectangular in plan view. The laminated exterior body 910 has a pair of long sides 911 and a pair of short sides 912 in plan view.

[0004] The valve device 950 is attached to the laminated exterior body 910. A specific heat-sealable film 860 is heat-sealed between the laminated exterior body 910 and the valve device 950. When the pressure (hereinafter also referred to as "internal pressure") inside the laminated exterior body 910 reaches a predetermined pressure due to gas (hereinafter also referred to as "internal gas") generated inside the laminated exterior body 910, the valve device 950 discharges the internal gas to the outside of the laminated exterior body 910 to reduce the internal pressure.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the valve device 950 protrudes from the region surrounded by a pair of long sides 911 and a pair of short sides 912 (hereinafter also referred to as the "outer package region"). Therefore, when a plurality of batteries 900 are accommodated in a case to form a module, it is necessary to secure a space (also referred to as a "valve device accommodation space") for accommodating the valve device 950 that protrudes from the outer package region within the case. The valve device accommodation space does not contribute to the battery reaction. As a result, the volume efficiency of the module may not be sufficient. The "volume efficiency of the module" indicates the ratio of the volume of the electrode body where the battery reaction occurs to the total volume of the module.

[0007] The present disclosure has been made in view of the above circumstances. The problem to be solved by one embodiment of the present disclosure is to provide a battery that can release internal gas to the outside when the internal pressure rises excessively and can improve the volume efficiency of the module.

Means for Solving the Problem

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

[0009] <1>The battery according to the first aspect of the present disclosure is an electrode body, a laminate outer package that houses the electrode body therein, and is provided with the laminate outer package has a mechanism that can be switched between a closed state that closes the inside and an open state that opens the inside to the outside of the laminate outer package, when the pressure inside the laminate outer package exceeds a threshold value, the mechanism switches from the closed state to the open state, the laminate outer package is rectangular parallelepiped, in plan view, the laminate outer package has a pair of first sides extending in a first direction and a pair of second sides extending in a second direction orthogonal to the first direction. In the plan view, the mechanism is located within a virtual region surrounded by a pair of first virtual lines including the pair of first sides and a pair of second virtual lines including the pair of second sides. The battery is such that, in a third direction orthogonal to each of the first direction and the second direction, the length of the mechanism is shorter than the length of the laminate exterior body.

[0010] The "laminate exterior body" refers to a case made of a laminate sheet. The "laminate sheet" refers to a sheet having 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. The "rectangular parallelepiped shape" refers to a concept that includes not only a perfect rectangular parallelepiped but also a substantial rectangular parallelepiped (for example, a shape in which a part of at least one side is chamfered, etc.). The "plan view" refers to viewing from a direction orthogonal to the main surface of the laminate exterior body (that is, the third direction).

[0011] When an abnormality occurs in the battery, gas (hereinafter also referred to as "internal gas") generated inside the laminate exterior body may be generated, and the pressure inside the laminate exterior body (hereinafter also referred to as "internal pressure") may rise excessively. In the first aspect, the laminate exterior body has a mechanism. Therefore, the battery of the first aspect can release the internal gas to the outside when the internal pressure rises excessively. As a result, the occurrence of rupture of the laminate exterior body of the battery of the first aspect is suppressed. That is, the safety of the battery of the first aspect is excellent. In the first aspect, the mechanism is located within the virtual region in the plan view. Further, in the third direction, the length of the mechanism is shorter than the length of the laminate exterior body. Therefore, when a plurality of batteries of the first aspect are housed in a case to form a module, it is not necessary to secure a conventional valve device housing space in the case. As a result, the battery of the first aspect can improve the volume efficiency of the module.

[0012] <2>The battery of the second aspect of the present disclosure is The laminate exterior body is composed of a laminate sheet, The laminate exterior body is a non-welded area where the laminate sheets are not welded to each other, a welded area that seals the non-welded area and where the laminate sheets are welded to each other, and has the non-welded area being a housing area for housing the electrode body, an intermediate area located between the housing area and the welded area, and includes the intermediate area being at least one through-hole penetrating the laminate sheet, a lid portion welded to the laminate sheet and closing the through-hole, and includes the thickness of the lid portion being thinner than the thickness of the laminate sheet, the mechanism including the lid portion closing the through-hole, the closed state indicating a state where the lid portion is not torn, the open state indicating a state where the lid portion is torn, the battery according to <1>.

[0013] In the second aspect, the mechanism includes a lid portion closing the through-hole. The thickness of the lid portion is thinner than the thickness of the laminate sheet. That is, the strength of the lid portion is relatively low. Therefore, when the internal pressure rises excessively, the lid portion is likely to tear. As a result, the battery of the second aspect can release internal gas to the outside with a simple configuration when the internal pressure rises excessively.

[0014] <3>The battery of the third aspect of the present disclosure the laminate exterior is composed of laminate sheets, the laminate exterior has a non-welded area where the laminate sheets are not welded to each other, a welded area that seals the non-welded area and where the laminate sheets are welded to each other, and has the non-welded area including a housing area for housing the electrode body, the welded area having a main portion with a specific welding width, at least one narrow part having a welding width shorter than the specific width, and having, the mechanism includes the narrow part, the closed state indicates a state where the laminate sheets are welded to each other at the narrow part, the open state indicates a state where the laminate sheets are separated from each other at the narrow part, and the battery according to <1>.

[0015] In the third aspect, the mechanism includes at least one narrow part. That is, the laminate sheets welded at the narrow part are more likely to be separated than the laminate sheets welded at the main part. Therefore, when the internal pressure rises excessively, the laminate sheets welded at the narrow part are likely to be separated. As a result, the battery of the third aspect can release internal gas to the outside with a simple configuration when the internal pressure rises excessively.

[0016] <4>The battery according to the fourth aspect of the present disclosure is the laminate exterior is composed of laminate sheets, the laminate exterior has, a non-welded region where the laminate sheets are not welded to each other, a welded region that seals the non-welded region and where the laminate sheets are welded to each other, and has, the non-welded region includes a housing region that houses the electrode body, the mechanism includes at least one check valve, the check valve has, a main body portion that forms a gas flow path communicating the non-welded region and the outside of the laminate exterior, an on-off valve that opens and closes the gas flow path, and includes, the welded region includes a region where the main body portion is interposed between the laminate sheets, the closed state indicates a state where the on-off valve closes the gas flow path, The battery according to <1>, wherein the open state indicates a state in which the on-off valve opens the gas flow path.

[0017] In the fourth aspect, the mechanism includes at least one check valve. The check valve can return from an open state to a closed state. Thereby, the battery of the fourth aspect can function as a battery even after the internal pressure has risen excessively.

Advantages of the Invention

[0018] According to the present disclosure, there is provided a battery that can release internal gas to the outside when the internal pressure rises excessively and can improve the volume efficiency of the module.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0020] Embodiments of the present disclosure will be described below. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments. In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect. In the present disclosure, a numerical range represented using "~" means a range including the numerical values described before and after "~" as a lower limit value and an upper limit value. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. In the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0021] Hereinafter, embodiments of the battery of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description thereof will not be repeated.

[0022] (1) First Embodiment As shown in FIG. 1, the battery 1A according to the first embodiment includes an electrode body 11, a laminate exterior body 12A, a positive electrode tab 13, a negative electrode tab 14, and a non-aqueous electrolyte (not shown). The battery 1A is a rectangular parallelepiped.

[0023] In the present embodiment, the longitudinal direction of the main surface of the battery 1A is defined as the X-axis direction, the short-side direction of the main surface of the battery 1A is defined as the Y-axis direction, and the thickness direction of the battery 1A is defined as the Z-axis direction. Each of the X-axis, Y-axis, and Z-axis is orthogonal to each other. The X-axis is an example of the first direction. The Y-axis is an example of the second direction. The Z-axis is an example of the third direction. Note that these directions do not limit the direction of use of the battery of the present disclosure.

[0024] The laminate exterior body 12A houses the electrode body 11 and the non-aqueous electrolyte therein. The positive electrode tab 13 protrudes from the laminate exterior body 12A in the positive X-axis direction. The negative electrode tab 14 protrudes from the laminate exterior body 12A in the negative X-axis direction.

[0025] The length L1 of the battery 1A in the X-axis direction (see FIG. 1) is, for example, 530 mm to 600 mm. The length L2 of the battery 1A in the Y-axis direction (see FIG. 1) is, for example, 80 mm to 110 mm. The length L3 of the battery 1A in the Z-axis direction (see FIG. 2) is, for example, 7.0 mm to 9.0 mm.

[0026] (1.1) Electrode Body The structure of the electrode body 11 is of a laminated type. As shown in FIG. 2, the electrode body 11 includes a plurality of positive electrode sheets 111, a plurality of negative electrode sheets 112, and a plurality of separator sheets 113. In the electrode body 11, the positive electrode sheets 111 and the negative electrode sheets 112 are alternately laminated along the Z-axis direction with the separator sheets 113 interposed therebetween.

[0027] The number of each of the positive electrode sheet 111, the negative electrode sheet 112, and the separator sheet 113 is not particularly limited and is appropriately selected according to the use of the battery 1A or the like.

[0028] (1.1.1) Positive Electrode Sheet The positive electrode sheet 111 has a positive electrode current collector 1111 (for example, aluminum foil or the like) and a positive electrode active material layer 1112 supported on both surfaces of the positive electrode current collector 1111. The positive electrode active material layer 1112 contains a positive electrode active material. The positive electrode active material releases or occludes lithium ions into / from the non-aqueous electrolyte. The positive electrode active material may be a known positive electrode active material (for example, LiNiO 2 、LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 etc.). The positive electrode active material layer 1112 may further contain a known conductive material (for example, carbon black or the like), lithium phosphate, and a known binder (for example, polyvinylidene fluoride or the like).

[0029] (1.1.2) Negative Electrode Sheet The negative electrode sheet 112 has a negative electrode current collector 1121 (for example, copper foil or the like) and a negative electrode active material layer 1122 supported on both surfaces of the negative electrode current collector 1121. The negative electrode active material layer 1122 contains a negative electrode active material. The negative electrode active material occludes lithium ions, which are charge carriers, from the non-aqueous electrolyte during charge and discharges and releases them into the non-aqueous electrolyte. The negative electrode active material may be a known negative electrode active material (artificial graphite, lithium alloy (for example, LiXM, where M is C, Si, Sn, Sb, Al, Mg, Ti, Bi, Ge, Pb, or P, etc., and X is a natural number), etc.). The negative electrode active material layer 1122 may further contain a known binder (for example, styrene-butadiene copolymer or the like).

[0030] (1.1.3) Separator Sheet Separator sheet 113 electrically insulates the positive electrode sheet 111 and the negative electrode sheet 112, and provides a migration path for lithium ions between the positive electrode active material layer 1112 and the negative electrode active material layer 1122. Examples of the separator sheet 113 include a porous film. Examples of the material of the porous film include polyethylene, polypropylene, and the like. The separator sheet 113 may have a single-layer structure or a multilayer structure.

[0031] (1.2) Laminate Exterior Body The laminate exterior body 12A covers the electrode body 11 and seals the electrode body 11 and the non-aqueous electrolyte together with the positive electrode tab 13 and the negative electrode tab 14. The laminate exterior body 12A has a single cup structure (see FIG. 2). The "laminate exterior body with a single cup structure" has a folding line, a single cup portion (recess) capable of accommodating the entire electrode body, and a flat portion, and indicates a single laminate exterior body in which the flat portion covers the recess when bent along the folding line.

[0032] As shown in FIG. 2, the laminate exterior body 12A has two mechanisms 2A, a laminate sheet 121, and a plurality of tab films 122. Each of the plurality of tab films 122 is welded to the positive electrode tab 13 or the negative electrode tab 14 and the laminate sheet 121. Details of the mechanism 2A will be described later with reference to FIG. 2.

[0033] As shown in FIG. 1, the laminate exterior body 12A has a non-welded region R12a and a welded region R12b. In the non-welded region R12a, the laminate sheets 121 are not welded to each other. In the welded region R12b, the laminate sheets 121 are welded to each other. The welded region R12b seals the non-welded region R12a. The non-welded region R12a has a housing region R12a1 and an intermediate region R12a2. The housing region R12a1 houses the electrode body 11. The intermediate region R12a2 is located between the housing region R12a1 and the welded region R12b.

[0034] The intermediate region R12a2 includes two through-holes TH121 that penetrate the laminate sheet 121 and a lid portion 21 that closes the through-holes TH121. The lid portion 21 is welded to the laminate sheet 121. In the first embodiment, the thickness L4 (the length L4 in the Z-axis direction) (see FIG. 2) of the lid portion 21 is thinner than the thickness L5 of the laminate sheet 121 (that is, the length L5 in the Z-axis direction) (see FIG. 2).

[0035] (1.2.1) Mechanism In the first embodiment, the mechanism 2A includes a lid portion 21 that closes the through-holes TH121. When the pressure inside the laminate exterior 12A exceeds a threshold value, the mechanism 2A switches from a closed state to an open state. The "closed state" indicates a state where the lid portion 21 is not torn. That is, the lid portion 21 closes the through-holes TH121. As a result, the inside of the laminate exterior 12A (that is, the non-welded region R12a) is closed. The "open state" indicates a state where the lid portion 21 is torn. That is, the lid portion 21 does not close the through-holes TH121. As a result, the inside of the laminate exterior 12A is open to the outside of the laminate exterior 12A.

[0036] The laminate exterior 12A has a rectangular parallelepiped shape. As shown in FIG. 1, the laminate exterior 12A has a pair of first sides S12a extending in the X-axis direction and a pair of second sides S12b extending in the Y-axis direction. The mechanism 2A is located within the virtual region VS12 in a plan view. The virtual region VS12 is a region surrounded by a pair of first virtual straight lines VS12a and a pair of second virtual straight lines VS12b. The pair of first virtual straight lines VS12a includes the pair of first sides S12a. The pair of second virtual straight lines VS12b includes the pair of second sides S12b. In the Z-axis direction, the length of the mechanism 2A (that is, the total length of the length L4 and the length L5) is shorter than the length of the laminate exterior 12A (that is, the length L3 of the battery 1A in the Z-axis direction).

[0037] The lid portion 21 contains a thermoplastic resin. Examples of the thermoplastic resin include olefin resins (e.g., polypropylene, polyethylene, etc.), polyvinyl chloride, polyvinylidene chloride, and the like. The lid portion 21 may be a resin sheet or may have the same layer structure as the laminate sheet 121.

[0038] (1.2.2) Laminate Sheet The laminate exterior body 12A is composed of a laminate sheet 121. The laminate sheet 121 has a metal layer 1211, an inner resin layer 1212, and an outer resin layer 1213. The inner resin layer 1212 is laminated on the surface of the metal layer 1211 on the side of the electrode body 11. The outer resin layer 1213 is laminated on the surface of the metal layer 1211 opposite to the side of the electrode body 11. The metal layer 1211 blocks the entry and exit of gas (e.g., moisture, air, etc.) between the outside and the inside of the battery 1A. The material of the metal layer 1211 is a metal (e.g., aluminum, etc.). The inner resin layer 1212 electrically insulates the electrode body 11, the positive electrode tab 13, and the negative electrode tab 14 from the metal layer 1211. The inner resin layer 1212 may contain a thermoplastic resin. The outer resin layer 1213 improves the durability of the laminate sheet 121. The outer resin layer 1213 may contain a thermoplastic resin. Examples of the thermoplastic resin for each of the inner resin layer 1212 and the outer resin layer 1213 are the same as those exemplified as the thermoplastic resin of the lid portion 21.

[0039] (1.2.3) Tab Film The tab film 122 has a function of electrically insulating the laminate sheet 121 from the positive electrode tab 13 and the negative electrode tab 14, and a function of joining the laminate sheet 121 to the positive electrode tab 13 and the negative electrode tab 14. The tab film 122 contains a thermoplastic resin. Examples of the thermoplastic resin of the tab film 122 are the same as those exemplified as the thermoplastic resin of the lid portion 21.

[0040] (1.3) Positive Electrode Tab The positive electrode tab 13 is electrically connected to a plurality of positive electrode current collectors 1111. Examples of the material of the positive electrode tab 13 include metals (such as stainless steel (SUS), etc.). The length L6 of the positive electrode tab 13 in the Y-axis direction (see FIG. 1) is, for example, 40 mm to 50 mm.

[0041] (1.4) Negative electrode tab The negative electrode tab 14 is electrically connected to a plurality of negative electrode current collectors 1121. Examples of the material of the negative electrode tab 14 include metals (such as stainless steel (SUS), etc.). The length L7 of the negative electrode tab 14 in the Y-axis direction (see FIG. 1) is, for example, 40 mm to 50 mm.

[0042] (1.5) Non-aqueous electrolyte The battery 1A includes a non-aqueous electrolyte. The non-aqueous electrolyte is housed together with the electrode body 11 in the laminate exterior body 12A. The non-aqueous electrolyte may be one in which a supporting salt (such as LiPF 6 etc.) as an electrolyte is dissolved or dispersed in a non-aqueous solvent (such as ethyl carbonate, etc.). The non-aqueous electrolyte may contain various additives (such as lithium bis(oxalato)borate, etc.).

[0043] (1.6) Function and effect As described with reference to FIGS. 1 and 2, the battery 1A includes an electrode body 11 and a laminate exterior body 12A. The laminate exterior body 12A has a mechanism 2A. The mechanism 2A is located within the virtual region VS12. In the Z-axis direction, the length of the mechanism 2A (that is, the total length of the length L4 and the length L5) is shorter than the length of the laminate exterior body 12A (that is, the length L3 of the battery 1A in the Z-axis direction). Thereby, when the internal pressure of the battery 1A rises excessively, the battery 1A can discharge the gas inside the battery 1A to the outside. As a result, the occurrence of rupture of the laminate exterior body 12A of the battery 1A is suppressed. The safety of the battery 1A is excellent. When the battery 1A is housed in a case to form a module, it is not necessary to secure a conventional valve device accommodation space in the case. As a result, the battery 1A can improve the volume efficiency of the module.

[0044] As described with reference to FIGS. 1 and 2, in the battery 1A, the thickness L4 (see FIG. 2) of the lid portion 21 is thinner than the thickness L5 (see FIG. 2) of the laminate sheet 121. The mechanism 2A includes the lid portion 21 that closes the through hole TH121. The closed state of the mechanism 2A indicates a state where the lid portion 21 is not torn. The open state of the mechanism 2A indicates a state where the lid portion 21 is torn. Accordingly, the strength of the lid portion 21 is relatively low. Therefore, when the internal pressure of the battery 1A rises excessively, the lid portion 21 is likely to be torn by the internal pressure of the battery 1A. As a result, the battery 1B has a simple configuration and can discharge the gas inside the battery 1B to the outside when the internal pressure of the battery 1B rises excessively.

[0045] (2) Second Embodiment The battery 1B according to the second embodiment of the present disclosure is the same as the battery 1A of the first embodiment except that the configuration of the mechanism is mainly different.

[0046] As shown in FIG. 3, the battery 1B includes an electrode body 11, a laminate exterior body 12B, a positive electrode tab 13, a negative electrode tab 14, and a non-aqueous electrolyte (not shown).

[0047] The laminate exterior body 12B is the same as the laminate exterior body 12A except that it has a mechanism 2B instead of the mechanism 2A.

[0048] The laminate exterior body 12B has four mechanisms 2B, a laminate sheet 121, and a plurality of tab films 122.

[0049] The laminate exterior body 12B has a non-welded region R12a and a welded region R12b. In the second embodiment, the welded region R12b has a main portion R12b1 and four narrow portions R12b2. The main portion R12b1 is a portion having a welding width of a specific width L8 (see FIG. 3). The narrow portion R12b2 has a welding width of a width L9 (see FIG. 3) shorter than the specific width L8. The portion of the welded region R12b that is not the four narrow portions R12b2 is composed of the main portion R12b1.

[0050] (2.1) Mechanism In the second embodiment, the mechanism 2B includes the narrow portion R12b2. The mechanism 2B switches from the closed state to the open state when the pressure inside the laminate exterior 12B exceeds the threshold value. The "closed state" indicates a state in which the laminate sheets 121 are welded to each other at the narrow portion R12b2. That is, the inside of the laminate exterior 12B (i.e., the non-welded region R12a) is closed. The "open state" indicates a state in which the laminate sheets 121 are separated from each other at the narrow portion R12b2. That is, the inside of the laminate exterior 12B is open to the outside of the laminate exterior 12B.

[0051] The laminate exterior 12B has a rectangular parallelepiped shape. The laminate exterior 12B has a pair of first sides S12a extending in the X-axis direction and a pair of second sides S12b extending in the Y-axis direction. As shown in FIG. 3, the mechanism 2B is located within the virtual region VS12 in a plan view. The virtual region VS12 is a region surrounded by a pair of first virtual straight lines VS12a and a pair of second virtual straight lines VS12b. The pair of first virtual straight lines VS12a includes the pair of first sides S12a. The pair of second virtual straight lines VS12b includes the pair of second sides S12b. In the Z-axis direction, the length of the mechanism 2B is shorter than the length of the laminate exterior 12B (i.e., the length L3 of the battery 1B in the Z-axis direction).

[0052] (2.2) Operational Effects As described with reference to FIG. 3, the battery 1B includes the electrode body 11 and the laminate exterior 12B. The laminate exterior 12B has the mechanism 2B. The mechanism 2B is located within the virtual region VS12. In the Z-axis direction, the length of the mechanism 2B is shorter than the length of the laminate exterior 12B (i.e., the length L3 of the battery 1B in the Z-axis direction). As a result, when the internal pressure of the battery 1B rises excessively, the battery 1B can release the gas inside the battery 1B to the outside. As a result, the occurrence of rupture of the laminate exterior body 12B of the battery 1B is suppressed. The safety of the battery 1B is excellent. When the battery 1B is housed in a case to form a module, it is not necessary to secure the conventional valve device housing space in the case. As a result, the battery 1B can improve the volume efficiency of the module.

[0053] As described with reference to FIG. 3, in the battery 1B, the welded region R12b has a main portion R12b1 and four narrow portions R12b2. The mechanism 2B includes the narrow portion R12b2. The closed state indicates a state in which the laminate sheets 121 are welded to each other at the narrow portion R12b2. The open state indicates a state in which the laminate sheets 121 are separated from each other at the narrow portion R12b2. As a result, the welded laminate sheets 121 at the narrow portion R12b2 are more likely to separate than the welded laminate sheets 121 at the main portion R12b1. Therefore, when the internal pressure of the battery 1B rises excessively, the welded laminate sheets 121 at the narrow portion R12b2 are likely to separate due to the internal pressure of the battery 1B. As a result, the battery 1B can release the gas inside the battery 1B to the outside with a simple configuration when the internal pressure of the battery 1B rises excessively.

[0054] (3) Third Embodiment The battery 1C of the third embodiment of the present disclosure is the same as the battery 1A of the first embodiment except that the configuration of the mechanism is mainly different.

[0055] As shown in FIG. 4, the battery 1C includes an electrode body 11, a laminate exterior body 12C, a positive electrode tab 13, a negative electrode tab 14, and a non-aqueous electrolyte (not shown).

[0056] The laminate exterior body 12C is the same as the laminate exterior body 12A except that it has a mechanism 2C instead of the mechanism 2A.

[0057] The laminated exterior body 12C has two mechanisms 2C, a laminated sheet 121, and a plurality of tab films 122.

[0058] (3.1) Mechanism In the third embodiment, the mechanism 2C includes two check valves 22. The check valve 22 is a known disk-type check valve. As shown in FIG. 5, the check valve 22 includes a main body portion 221 and an on-off valve 222. The on-off valve 222 is disposed inside the main body portion 221. The main body portion 221 is a cylindrical object. The main body portion 221 forms a gas flow path R21. The gas flow path R21 communicates the non-welded region R12a with the outside of the laminated exterior body 12C. The on-off valve 222 opens and closes the gas flow path R21. The on-off valve 222 has a lid portion 2221 and a spring 2222.

[0059] When the pressure inside the laminated exterior body 12C exceeds a threshold value, the mechanism 2C switches from the closed state to the open state. The "closed state" indicates a state where the on-off valve 222 closes the gas flow path R21. The main body portion 221 has a partition inner wall 2210. Specifically, the closed state is a state where the lid portion 2221 of the on-off valve 222 and the partition inner wall 2210 of the main body portion 221 are in contact. The "open state" indicates a state where the on-off valve 222 opens the gas flow path R21. Specifically, the open state is a state where the lid portion 2221 of the on-off valve 222 and the partition inner wall 2210 of the main body portion 221 are in contact.

[0060] The laminated exterior body 12C is in the shape of a rectangular parallelepiped. The laminated exterior body 12C has a pair of first sides S12a extending in the X-axis direction and a pair of second sides S12b extending in the Y-axis direction. The welding region R12b includes a region where the main body portion 221 is interposed between the laminated sheets 121. As shown in FIG. 4, the mechanism 2C is located within the virtual region VS12 in a plan view. The virtual region VS12 is a region surrounded by a pair of first virtual lines VS12a and a pair of second virtual lines VS12b. The pair of first virtual lines VS12a includes the pair of first sides S12a. The pair of second virtual lines VS12b includes the pair of second sides S12b. As shown in FIG. 5, in the Z-axis direction, the length L10 (see FIG. 5) of the mechanism 2C is shorter than the length L3 (see FIG. 5) of the laminated exterior body 12C.

[0061] (3.2) Function and effect As described with reference to FIGS. 4 and 5, the battery 1C includes an electrode body 11 and a laminated exterior body 12C. The laminated exterior body 12C has a mechanism 2C. The mechanism 2C is located within the virtual region VS12. In the Z-axis direction, the length L10 (see FIG. 5) of the mechanism 2C is shorter than the length L3 (see FIG. 5) of the laminated exterior body 12C. Thereby, when the internal pressure of the battery 1C rises excessively, the gas inside the battery 1C can be discharged to the outside. As a result, the occurrence of rupture of the laminated exterior body 12C of the battery 1C is suppressed. The safety of the battery 1C is excellent. When the battery 1C is housed in a case to form a module, it is not necessary to secure the conventional valve device housing space in the case. As a result, the battery 1C can improve the volume efficiency of the module.

[0062] As described with reference to FIGS. 4 and 5, the mechanism 2C includes two check valves 22. The check valve 22 includes a main body portion 221 and an on-off valve 222. The welding region R12b includes a region where the main body portion 221 is interposed between the laminated sheets 121. The closed state indicates a state where the on-off valve 222 closes the gas flow path R21. The open state indicates a state where the on-off valve 222 opens the gas flow path R21. The check valve 22 can return from the open state to the closed state. As a result, the battery 1C can be reused even if the internal pressure of the battery 1C has risen excessively two or more times.

[0063] (4) Modification In the battery 1A, the laminated exterior body 12A has two mechanisms 2A (i.e., the lid portion 21 that closes the through hole TH121), but the present disclosure is not limited thereto. The laminated exterior body 12A may have one mechanism 2A, or may have three or more mechanisms 2A. In addition to the mechanism 2A, the laminated exterior body 12A may have at least one of one or more mechanisms 2B and one or more mechanisms 2C.

[0064] In the battery 1B, the laminated exterior body 12B has four mechanisms 2B (i.e., the narrow portion R12b2), but the present disclosure is not limited thereto. The laminated exterior body 12B may have 1 to 3 mechanisms 2A, or may have 5 or more mechanisms 2A. In addition to the mechanism 2B, the laminated exterior body 12B may have at least one of one or more mechanisms 2A and one or more mechanisms 2C.

[0065] In the battery 1C, the laminated exterior body 12C has two mechanisms 2C (i.e., the check valve), but the present disclosure is not limited thereto. The laminated exterior body 12B may have one mechanism 2C, or may have three or more mechanisms 2A. In addition to the mechanism 2C, the laminated exterior body 12C may have at least one of one or more mechanisms 2A and one or more mechanisms 2B.

[0066] In the batteries 1A to 1C, the structure of the electrode body 11 is of a stacked type, but the present disclosure is not limited thereto. The structure of the electrode body of the present disclosure may be of a wound type.

[0067] The laminate exterior bodies 12A to 12C have a single cup structure (see FIG. 2), but the present disclosure is not limited thereto. In the present disclosure, the laminate exterior bodies 12A to 12C may have a double cup structure. The "double cup structure" means a laminate exterior body having a folding line, one first cup portion (recess) capable of accommodating a part of the electrode body, and one second cup portion (recess) capable of accommodating a part of the electrode body, and when bent along the folding line, the entire electrode body can be accommodated in the space formed by the overlapping of the first cup portion and the second cup.

[0068] In the batteries 1A to 1C, the positive electrode tab 13 protrudes from the laminate exterior bodies 12A to 12C in the positive Y-axis direction, and the negative electrode tab 14 protrudes from the laminate exterior bodies 12A to 12C in the negative Y-axis direction, but the present disclosure is not limited thereto. In the present disclosure, the positive electrode tab 13 and the negative electrode tab 14 may protrude from the laminate exterior bodies 12A to 12C in the positive Y-axis direction or the negative Y-axis direction.

Description of Reference Numerals

[0069] 1A to 1C: Batteries, 11: Electrode body, 111: Positive electrode sheet, 1111: Positive electrode current collector, 1112: Positive electrode active material layer, 112: Negative electrode sheet, 1121: Negative electrode current collector, 1122: Negative electrode active material layer, 113: Separator sheet, 12A to 12C: Laminate exterior bodies, 121: Laminate sheet, 1211: Metal layer, 1212: Inner resin layer, 1213: Outer resin layer, 122: Tab film, 13: Positive electrode tab, 14: Negative electrode tab, 2A to 2C: Mechanisms, 21: Cover portion, TH121: Through hole, 22: Check valve, 221: Body portion, 222: Opening and closing valve, 2210: Inner wall, 2221: Cover portion, 2222: Spring, R12a: Non-welded region, R12a1: Accommodation region, R12a2: Intermediate region, R12b: Welded region, R12b1: Main portion, R12b2: Narrow portion, R21: Gas flow path, S12a: Side, S12b: Side, VS12: Virtual region, VS12a: Virtual straight line, VS12b: Virtual straight line

Claims

1. An electrode body, A laminated exterior body that houses the electrode body inside, Comprising, The laminated exterior body has a mechanism that can be switched between a closed state that closes the interior and an open state that opens the interior to the outside of the laminated exterior body, When the pressure inside the laminated exterior body exceeds a threshold value, the mechanism switches from the closed state to the open state, The laminated exterior body is in the shape of a rectangular parallelepiped, In plan view, the laminated exterior body has a pair of first sides extending in a first direction and a pair of second sides extending in a second direction orthogonal to the first direction, In the plan view, the mechanism is located within a virtual region surrounded by a pair of first virtual straight lines including the pair of first sides and a pair of second virtual straight lines including the pair of second sides, A battery in which, in a third direction orthogonal to each of the first direction and the second direction, the length of the mechanism is shorter than the length of the laminated exterior body.

2. The laminated exterior body is composed of laminated sheets, The laminated exterior body has, A non-welded region where the laminated sheets are not welded together, A welded region that seals the non-welded region and where the laminated sheets are welded together, Having, The non-welded region includes, A housing region that houses the electrode body, An intermediate region located between the housing region and the welded region, Including, The intermediate region has, At least one through-hole penetrating the laminated sheet, A lid portion welded to the laminated sheet and closing the through-hole, Including, The thickness of the lid portion is thinner than the thickness of the laminated sheet, The mechanism includes the lid portion that closes the through-hole, The closed state indicates a state where the lid portion is not torn, The open state indicates a state where the lid portion is torn. The battery according to claim 1.

3. The laminated exterior body is composed of laminated sheets, The laminated exterior body has, A non-welded region where the laminated sheets are not welded together, A welded region that seals the non-welded region and where the laminated sheets are welded together, Having, The non-welded region includes a housing region that houses the electrode body, The welded region has, A main portion having a welding width of a specific width, At least one narrow portion having a welding width shorter than the specific width, Having, The mechanism includes the narrow portion, The closed state indicates a state where the laminated sheets are welded together at the narrow portion. The battery according to claim 1, wherein the open state indicates a state in which the laminate sheets are separated from each other in the narrow portion.

4. The laminate exterior body is composed of laminate sheets, The laminate exterior body, a non-welded region where the laminate sheets are not welded to each other, a welded region that seals the non-welded region and where the laminate sheets are welded to each other, has, the non-welded region includes a housing region that houses the electrode body, the mechanism includes at least one check valve, the check valve, a main body portion that forms a gas flow path communicating the non-welded region with the outside of the laminate exterior body, an opening / closing valve that opens and closes the gas flow path, includes, the welded region includes a region where the main body portion is interposed between the laminate sheets, the closed state indicates a state in which the opening / closing valve closes the gas flow path, the open state indicates a state in which the opening / closing valve opens the gas flow path, the battery according to claim 1.

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