Battery

Abstract

Provided is a battery capable of releasing internal gas to the outside when internal pressure is excessively increased, and capable of improving the volumetric efficiency of a module. A battery according to the present disclosure is provided with an electrode body and a laminated exterior body that accommodates the electrode body therein. The laminated exterior body has a mechanism. The mechanism can be switched between a closed state in which the interior is closed and an open state in which the interior is opened to the outside of the laminated exterior body. The mechanism switches from the closed state to the open state when the pressure inside the laminated exterior body exceeds a threshold value. The mechanism is located in a virtual region surrounded by a pair of first virtual straight lines including a pair of first sides extending in a first direction and a pair of second virtual straight lines including a pair of second sides extending in a second direction when viewed in a plane. In a third direction orthogonal to the first direction and the second direction, the length of the mechanism is shorter than the length of the laminated exterior body.

Description

Technical Field

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

[0002] Japanese Patent Application Laid-Open No. 2023-11650 specifically discloses Figure 6 The battery 900 shown in the figure (hereinafter, also referred to as "battery 900") includes a housing 910 (hereinafter, also referred to as "laminated outer casing 910"), a battery 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 thermal fusion film 960.

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

[0004] The valve device 950 is mounted on the laminated outer casing 910. A specific heat-fusible film 860 is heat-fused between the laminated outer casing 910 and the valve device 950. When the pressure inside the laminated outer casing 910 (hereinafter, also referred to as "internal pressure") reaches a predetermined pressure due to the gas generated inside the laminated outer casing 910 (hereinafter, also referred to as "internal gas"), the valve device 950 discharges the internal gas to the outside of the laminated outer casing 910 to reduce the internal pressure.

[0005] However, the valve device 950 extends from an area surrounded by a pair of long sides 911 and a pair of short sides 912 (hereinafter, also referred to as the "external body area"). Therefore, when a plurality of batteries 900 are housed in a housing to form a module, it is necessary to ensure a space in the housing for accommodating the valve device 950 extending from the external body area (also referred to as the "valve device accommodating space"). The valve device accommodating space does not contribute to the battery reaction. As a result, the volumetric efficiency of the module may be insufficient. The "volume efficiency of the module" indicates the ratio of the volume of the electrode body that performs the battery reaction to the overall volume of the module. Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present disclosure has been completed in view of the above circumstances.

[0008] A 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 that can improve the volume efficiency of the module.

[0009] Means for solving problems

[0010] Means for solving the above-mentioned problems include the following embodiments.

[0011] <1> A battery according to a first aspect of the present disclosure includes:

[0012] an electrode body; and

[0013] A laminated outer package is provided to accommodate the electrode assembly therein.

[0014] The laminated outer casing has a mechanism capable of switching between a closed state in which the interior is sealed and an open state in which the interior is opened to the outside of the laminated outer casing,

[0015] When the pressure inside the laminated outer casing exceeds a threshold value, the mechanism switches from the closed state to the open state.

[0016] The laminated outer casing is in the shape of a rectangular parallelepiped.

[0017] The laminated outer casing 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 when viewed in a plan view.

[0018] 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 when viewed from the plane.

[0019] In a third direction perpendicular to the first direction and the second direction, the length of the mechanism is shorter than the length of the laminated exterior body.

[0020] "Laminated outer casing" means an outer casing made of a laminated sheet. "Laminated sheet" means a sheet having a metal layer, a first resin layer laminated on a main surface of one side of the metal layer, and a second resin layer laminated on a main surface of the other side of the metal layer. "Cuboid" is a concept that includes not only a complete cuboid but also a substantial cuboid (for example, a shape in which a portion of at least one side is chamfered, etc.). "Plane observation" means observation from a direction orthogonal to the main surface of the laminated outer casing (i.e., the third direction).

[0021] When the battery is abnormal, gas (hereinafter, also referred to as "internal gas") is generated inside the laminated outer casing and the pressure inside the laminated outer casing (hereinafter, also referred to as "internal pressure") rises excessively. In the first embodiment, the laminated outer casing has a mechanism. Therefore, the battery of the first embodiment can release the internal gas to the outside when the internal pressure rises excessively. As a result, the occurrence of rupture of the laminated outer casing of the battery of the first embodiment is suppressed. In other words, the battery of the first embodiment has excellent safety.

[0022] In the first embodiment, the mechanism is located within the imaginary region when viewed from the plane. Moreover, in the third direction, the length of the mechanism is shorter than the length of the laminated outer casing. Therefore, when a plurality of batteries of the first embodiment are housed in a housing to form a module, it is not necessary to ensure a conventional valve device housing space in the housing. As a result, the battery of the first embodiment can improve the volume efficiency of the module.

[0023] <2> The battery according to the second aspect of the present disclosure is as follows <1> The battery,

[0024] The laminated outer body is composed of a laminated sheet,

[0025] The laminated outer casing has:

[0026] a non-welded region where the laminated sheets are not welded to each other; and

[0027] The non-welded area is sealed and the laminated sheets are welded to each other.

[0028] The non-welding area comprises:

[0029] a receiving area for receiving the electrode body; and

[0030] The middle area is located between the receiving area and the welding area.

[0031] The intermediate region comprises:

[0032] at least one through hole penetrating the laminate; and

[0033] A cover portion is welded to the laminate sheet to block the through hole.

[0034] The thickness of the cover portion is thinner than the thickness of the laminated sheet,

[0035] The mechanism includes the cover portion that blocks the through hole,

[0036] The closed state means that the cover is not torn.

[0037] The open state indicates a state in which the cover portion is torn.

[0038] In the second embodiment, the mechanism includes a cover portion that blocks the through hole. The thickness of the cover portion is thinner than the thickness of the laminate. In other words, the strength of the cover portion is relatively low. Therefore, when the internal pressure rises excessively, the cover portion is easy to rupture. As a result, the battery of the second embodiment can release the internal gas to the outside when the internal pressure rises excessively with a simple structure.

[0039] <3> The battery according to the third aspect of the present disclosure is as follows <1> The battery,

[0040] The laminated outer body is composed of a laminated sheet,

[0041] The laminated outer casing has:

[0042] a non-welded region where the laminated sheets are not welded to each other; and

[0043] The non-welded area is sealed and the laminated sheets are welded to each other.

[0044] The non-welding area includes a receiving area for receiving the electrode body.

[0045] The fusion zone has:

[0046] The main part has a weld width of a specific width; and

[0047] At least one narrow portion has a weld width that is shorter than the specific width.

[0048] The mechanism includes the narrow part,

[0049] The closed state means that the laminated sheets are fused to each other at the narrow portion.

[0050] The open state indicates a state in which the laminated sheets are separated from each other at the narrow portion.

[0051] In the third embodiment, the structure includes at least one narrow portion. That is, the laminated sheets welded in the narrow portion are easier to separate than the laminated sheets welded in the main portion. Therefore, when the internal pressure rises excessively, the laminated sheets welded in the narrow portion are easier to separate. As a result, the battery of the third embodiment can release the internal gas to the outside with a simple structure when the internal pressure rises excessively.

[0052] <4> The battery according to the fourth aspect of the present disclosure is as follows <1> The battery,

[0053] The laminated outer body is composed of a laminated sheet,

[0054] The laminated outer casing has:

[0055] a non-welded region where the laminated sheets are not welded to each other; and

[0056] The non-welded area is sealed and the laminated sheets are welded to each other.

[0057] The non-welding area includes a receiving area for receiving the electrode body.

[0058] The mechanism comprises at least one check valve,

[0059] The check valve comprises:

[0060] a main body portion forming a gas flow path connecting the non-welded region and the outside of the laminated outer casing; and

[0061] The on-off valve is used to open and close the gas flow path.

[0062] The fusion region includes a region where the main body is located between the laminated sheets.

[0063] The closed state indicates a state in which the on-off valve closes the gas flow path.

[0064] The open state indicates a state in which the on-off valve opens the gas flow path.

[0065] In the fourth aspect, the mechanism includes at least one check valve. The check valve can be restored from an open state to a closed state. Thus, the battery of the fourth aspect functions as a battery even after the internal pressure increases excessively.

[0066] According to the present disclosure, a battery is provided which can release internal gas to the outside when the internal pressure increases excessively and can improve the volume efficiency of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Typical embodiments of the present invention will be described in detail based on the following drawings, in which:

[0068] Figure 1 is a front view of a battery according to a first embodiment of the present disclosure;

[0069] Figure 2 yes Figure 1 II-II line cross-sectional view;

[0070] Figure 3 is a front view of a battery according to a second embodiment of the present disclosure;

[0071] Figure 4 is a front view of a battery according to a third embodiment of the present disclosure;

[0072] Figure 5 yes Figure 4 VV line cross-sectional view;

[0073] Figure 6 This is a front view of a conventional battery. DETAILED DESCRIPTION

[0074] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples illustrate the embodiments and do not limit the scope of the embodiments.

[0075] In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.

[0076] In the present disclosure, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0077] In the numerical range recorded in stages in the present disclosure, the upper limit or lower limit recorded in one numerical range can also be replaced by the upper limit or lower limit of the numerical range recorded in other stages. In the numerical range recorded in the present disclosure, the upper limit or lower limit of the numerical range can also be replaced by the value shown in the embodiment.

[0078] Hereinafter, embodiments of the battery disclosed herein will be described with reference to the accompanying drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

[0079] (1) First Embodiment

[0080] like Figure 1 As shown, the battery 1A according to the first embodiment includes an electrode body 11, a laminated outer casing 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 object.

[0081] In the present embodiment, the long side direction of the main surface of the battery 1A is set as the X-axis direction, the short side direction of the main surface of the battery 1A is set as the Y-axis direction, and the thickness direction of the battery 1A is set as the Z-axis direction. The X-axis, the Y-axis, and the Z-axis are 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. In addition, these directions do not limit the directions of the battery of the present disclosure when it is used.

[0082] The laminated outer casing 12A contains the electrode assembly 11 and the non-aqueous electrolyte. The positive electrode tab 13 protrudes from the laminated outer casing 12A in the positive direction of the X axis. The negative electrode tab 14 protrudes from the laminated outer casing 12A in the negative direction of the X axis.

[0083] The length L1 of the battery 1A in the X-axis direction (see Figure 1 ) is, for example, 530 mm to 600 mm. The length L2 of the battery 1A in the Y-axis direction (see Figure 1 ) is, for example, 80 mm to 110 mm. The length L3 of the battery 1A in the Z-axis direction (see Figure 2 ) For example, 7.0mm to 9.0mm.

[0084] (1.1) Electrode body

[0085] The electrode body 11 has a stacked structure. Figure 2As shown, the electrode body 11 includes a plurality of positive electrode sheets 111, a plurality of negative electrode sheets 112, and a plurality of separators 113. The electrode body 11 is formed by alternately stacking the positive electrode sheets 111 and the negative electrode sheets 112 with the separators 113 interposed therebetween along the Z-axis direction.

[0086] The number of each of the positive electrode sheet 111 , the negative electrode sheet 112 , and the separator 113 is not particularly limited, and is appropriately selected depending on the purpose of the battery 1A and the like.

[0087] (1.1.1) Positive electrode

[0088] The positive electrode sheet 111 has a positive electrode current collector 1111 (for example, aluminum foil, etc.) and a positive electrode active material layer 1112 supported on both sides 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 lithium ions into the non-aqueous electrolyte or absorbs lithium ions from the non-aqueous electrolyte. The positive electrode active material is a known positive electrode active material (for example, LiNiO2, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The positive electrode active material layer 1112 may further contain a known conductive material (for example, carbon black), trilithium phosphate, and a known binder (for example, polyvinylidene fluoride).

[0089] (1.1.2) Negative electrode

[0090] The negative electrode sheet 112 has a negative electrode collector 1121 (for example, copper foil, etc.) and a negative electrode active material layer 1122 supported on both sides of the negative electrode collector 1121. The negative electrode active material layer 1122 contains a negative electrode active material. The negative electrode active material absorbs lithium ions as charge carriers from the non-aqueous electrolyte and releases them into the non-aqueous electrolyte during charging and discharging. The negative electrode active material can be a known negative electrode active material (artificial graphite, lithium alloy (for example, LiXM, M is C, Si, Sn, Sb, Al, Mg, Ti, Bi, Ge, Pb or P, etc., X is a natural number)). The negative electrode active material layer 1122 may also contain a known binder (for example, styrene butadiene copolymer, etc.).

[0091] (1.1.3) Separator

[0092] The separator 113 electrically insulates the positive electrode sheet 111 and the negative electrode sheet 112, and provides a path for lithium ions to move between the positive electrode active material layer 1112 and the negative electrode active material layer 1122. As the separator 113, a porous film or the like can be cited. As the material of the porous film, for example, polyethylene, polypropylene, etc. can be cited. The separator 113 can be a single-layer structure or a multi-layer structure.

[0093] (1.2) Laminated outer body

[0094] The laminated outer package 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 laminated outer package 12A has a single cup structure (see Figure 2 ). The “single cup structure laminated outer package” means a laminated outer package having a bending line, a cup portion (recessed portion) capable of accommodating the entire electrode body, and a flat portion, and being bent along the bending line so that the flat portion covers the recessed portion.

[0095] like Figure 2 As shown, the laminated outer package 12A has two structures 2A, a laminate sheet 121, and a plurality of tab films 122. The plurality of tab films 122 are respectively welded to the positive electrode tab 13 or the negative electrode tab 14 and the laminate sheet 121. For details of the structure 2A, refer to Figure 2 And then described.

[0096] like Figure 1 As shown, the laminated outer package 12A has a non-welding region R12a and a welding region R12b. In the non-welding region R12a, the laminated sheets 121 are not welded to each other. In the welding region R12b, the laminated sheets 121 are welded to each other. The welding region R12b seals the non-welding region R12a. The non-welding region R12a has a receiving region R12a1 and an intermediate region R12a2. The receiving region R12a1 receives the electrode body 11. The intermediate region R12a2 is located between the receiving region R12a1 and the welding region R12b.

[0097] The middle region R12a2 includes two through holes TH121 penetrating the laminate sheet 121 and a cover 21 blocking the through holes TH121. The cover 21 is welded to the laminate sheet 121. In the first embodiment, the thickness L4 (the length L4 in the Z-axis direction) of the cover 21 (see Figure 2 ) is greater than the thickness L5 (i.e., the length L5 in the Z-axis direction) of the laminate 121 (refer to Figure 2 )Thin.

[0098] (1.2.1) Institution

[0099] In the first embodiment, the mechanism 2A includes a cover portion 21 that blocks the through hole TH121. If the pressure inside the laminated outer casing 12A exceeds a threshold value, the mechanism 2A switches from a closed state to an open state. The "closed state" indicates a state in which the cover portion 21 is not torn. In other words, the cover portion 21 blocks the through hole TH121. Thus, the interior of the laminated outer casing 12A (i.e., the non-welded region R12a) is closed. The "open state" indicates a state in which the cover portion 21 is torn. In other words, the cover portion 21 does not block the through hole TH121. Thus, the interior of the laminated outer casing 12A is open to the outside of the laminated outer casing 12A.

[0100] The laminated outer package 12A is in the shape of a rectangular parallelepiped. Figure 1As shown, the laminated outer casing 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 in the imaginary area VS12 when viewed in a planar manner. The imaginary area VS12 is an area surrounded by a pair of first imaginary straight lines VS12a and a pair of second imaginary straight lines VS12b. A pair of first imaginary straight lines VS12a includes a pair of first sides S12a. A pair of second imaginary straight lines VS12b includes a pair of second sides S12b. In the Z-axis direction, the length of the mechanism 2A (i.e., the total length of the length L4 and the length L5) is shorter than the length of the laminated outer casing 12A (i.e., the length L3 of the battery 1A in the Z-axis direction).

[0101] The cover 21 includes a thermoplastic resin. Examples of the thermoplastic resin include olefin resins (eg, polypropylene, polyethylene, etc.), polyvinyl chloride, polyvinylidene chloride, etc. The cover 21 may be a resin sheet or may have the same layer structure as the laminate sheet 121 .

[0102] (1.2.2) Laminated Sheet

[0103] The laminated outer 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 electrode body 11 side. The outer resin layer 1213 is laminated on the surface of the metal layer 1211 on the side opposite to the electrode body 11 side. The metal layer 1211 cuts off the entry and exit of gas (for example, moisture, air, etc.) between the outside of the battery 1A and the inside of the battery 1A. The material of the metal layer 1211 is metal (for example, 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 include a thermoplastic resin. Examples of the thermoplastic resins of each of the inner resin layer 1212 and the outer resin layer 1213 include the same resins as those exemplified as the thermoplastic resin of the lid portion 21 .

[0104] (1.2.3) Ear membrane

[0105] The tab film 122 has the function of electrically insulating the laminate sheet 121 from the positive electrode tab 13 and the negative electrode tab 14, and the function of bonding the laminate sheet 121 to the positive electrode tab 13 and the negative electrode tab 14. The tab film 122 contains a thermoplastic resin. As the thermoplastic resin of the tab film 122, the same resin as the resin exemplified as the thermoplastic resin of the cover 21 can be cited.

[0106] (1.3) Positive electrode tab

[0107] The positive electrode tab 13 is electrically connected to the plurality of positive electrode current collectors 1111. The material of the positive electrode tab 13 may be metal (for example, stainless steel (SUS)). The length L6 of the positive electrode tab 13 in the Y-axis direction (see Figure 1 ) For example, 40mm~50mm.

[0108] (1.4) Negative electrode tab

[0109] The negative electrode tab 14 is electrically connected to the plurality of negative electrode current collectors 1121. The negative electrode tab 14 may be made of metal (for example, stainless steel (SUS)). The length L7 of the negative electrode tab 14 in the Y-axis direction (see Figure 1 ) For example, 40mm~50mm.

[0110] (1.5) Non-aqueous electrolyte

[0111] The battery 1A includes a non-aqueous electrolyte. The non-aqueous electrolyte is contained in the laminated outer package 12A together with the electrode body 11. The non-aqueous electrolyte is an electrolyte obtained by dissolving or dispersing a supporting salt (e.g., LiPF6, etc.) as an electrolyte in a non-aqueous solvent (e.g., ethyl carbonate, etc.). The non-aqueous electrolyte may also contain various additives (e.g., lithium bis(oxalatoborate, etc.).

[0112] (1.6) Effects

[0113] As reference Figure 1 and Figure 2 As described above, the battery 1A includes an electrode body 11 and a laminated outer body 12A. The laminated outer body 12A includes a mechanism 2A. The mechanism 2A is located in the imaginary area VS12. In the Z-axis direction, the length of the mechanism 2A (i.e., the total length of the length L4 and the length L5) is shorter than the length of the laminated outer body 12A (i.e., the length L3 of the battery 1A in the Z-axis direction).

[0114] Thus, the battery 1A can release the gas inside the battery 1A to the outside when the internal pressure of the battery 1A rises excessively. As a result, the occurrence of rupture of the laminated outer casing 12A of the battery 1A is suppressed. The battery 1A has excellent safety. When the battery 1A is housed in a housing to form a module, it is not necessary to ensure the conventional valve device housing space in the housing. As a result, the battery 1A can improve the volume efficiency of the module.

[0115] As reference Figure 1 and Figure 2 As described above, in the battery 1A, the thickness L4 of the cover portion 21 (see Figure 2 ) is greater than the thickness L5 of the laminate 121 (refer to Figure 2) is thin. The mechanism 2A includes a cover 21 that blocks the through hole TH121. The closed state of the mechanism 2A indicates a state in which the cover 21 is not torn. The open state of the mechanism 2A indicates a state in which the cover 21 is torn.

[0116] As a result, the strength of the cover 21 is relatively low. Therefore, when the internal pressure of the battery 1A rises excessively, the cover 21 is easily ruptured by the internal pressure of the battery 1A. As a result, the battery 1B can release the gas inside the battery 1B to the outside when the internal pressure of the battery 1B rises excessively with a simple structure.

[0117] (2) Second Embodiment

[0118] The battery 1B according to the second embodiment of the present disclosure is different mainly in the mechanical configuration, and is otherwise the same as the battery 1A according to the first embodiment.

[0119] like Figure 3 As shown, the battery 1B includes an electrode body 11 , a laminated outer casing 12B, a positive electrode tab 13 , a negative electrode tab 14 , and a non-aqueous electrolyte (not shown).

[0120] The laminated external package 12B is the same as the laminated external package 12A except that the laminated external package 12B includes the mechanism 2B instead of the mechanism 2A.

[0121] The laminated outer casing 12B includes four structures 2B, a laminated sheet 121 , and a plurality of tab films 122 .

[0122] The laminated outer casing 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 has a specific width L8 (see Figure 3 ) of the weld width. The narrow portion R12b2 has a width L9 shorter than the specific width L8 (see Figure 3 The portions of the weld region R12b other than the four narrow portions R12b2 are composed of the main portion R12b1.

[0123] (2.1) Institution

[0124] In the second embodiment, the mechanism 2B includes a narrow portion R12b2. If the pressure inside the laminated outer casing 12B exceeds a threshold value, the mechanism 2B switches from a closed state to an open state. The "closed state" indicates a state in which the laminated sheets 121 are fused to each other at the narrow portion R12b2. In other words, the interior of the laminated outer casing 12B (i.e., the non-fused region R12a) is closed. The "open state" indicates a state in which the laminated sheets 121 are separated from each other at the narrow portion R12b2. In other words, the interior of the laminated outer casing 12B is open to the outside of the laminated outer casing 12B.

[0125] The laminated outer casing 12B is in the shape of a rectangular parallelepiped. The laminated outer casing 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. Figure 3 As shown, the mechanism 2B is located in the imaginary area VS12 when viewed in a plan view. The imaginary area VS12 is an area surrounded by a pair of first imaginary straight lines VS12a and a pair of second imaginary straight lines VS12b. The pair of first imaginary straight lines VS12a includes a pair of first sides S12a. The pair of second imaginary straight lines VS12b includes a pair of second sides S12b. In the Z-axis direction, the length of the mechanism 2B is shorter than the length of the laminated outer casing 12B (i.e., the length L3 of the battery 1B in the Z-axis direction).

[0126] (2.2) Effects

[0127] As reference Figure 3 As described above, the battery 1B includes the electrode body 11 and the laminated outer body 12B. The laminated outer body 12B includes the mechanism 2B. The mechanism 2B is located in the virtual area VS12. In the Z-axis direction, the length of the mechanism 2B is shorter than the length of the laminated outer body 12B (i.e., the length L3 of the battery 1B in the Z-axis direction).

[0128] Thus, the battery 1B can release the gas inside the battery 1B to the outside when the internal pressure of the battery 1B rises excessively. As a result, the occurrence of rupture of the laminated outer casing 12B of the battery 1B is suppressed. The battery 1B has excellent safety. When the battery 1B is housed in the outer casing to form a module, it is not necessary to ensure the conventional valve device housing space in the outer casing. As a result, the battery 1B can improve the volume efficiency of the module.

[0129] As reference Figure 3 As described above, in the battery 1B, the welded region R12b has a main portion R12b1 and four narrow portions R12b2. The mechanism 2B includes the narrow portions R12b2. The closed state indicates that the laminated sheets 121 are welded to each other at the narrow portions R12b2. The open state indicates that the laminated sheets 121 are separated from each other at the narrow portions R12b2.

[0130] As a result, the laminated sheets 121 welded in the narrow portion R12b2 are easier to separate than the laminated sheets 121 welded in the main portion R12b1. Therefore, when the internal pressure of the battery 1B rises excessively, the laminated sheets 121 welded in the narrow portion R12b2 are easier 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 structure when the internal pressure of the battery 1B rises excessively.

[0131] (3) Third Embodiment

[0132] The battery 1C according to the third embodiment of the present disclosure is different mainly in the mechanical configuration, and is otherwise the same as the battery 1A according to the first embodiment.

[0133] like Figure 4 As shown, the battery 1C includes an electrode body 11 , a laminated outer casing 12C, a positive electrode tab 13 , a negative electrode tab 14 , and a non-aqueous electrolyte (not shown).

[0134] The laminated external housing 12C is the same as the laminated external housing 12A except that the laminated external housing 12C includes a mechanism 2C instead of the mechanism 2A.

[0135] The laminated outer casing 12C includes two structures 2C, a laminate sheet 121 , and a plurality of tab films 122 .

[0136] (3.1) Institution

[0137] In the third embodiment, the mechanism 2C includes two check valves 22. The check valves 22 are known disk check valves. Figure 5 As shown, the check valve 22 includes a main body 221 and an opening and closing valve 222. The opening and closing valve 222 is arranged inside the main body 221. The main body 221 is a cylindrical object. The main body 221 forms a gas flow path R21. The gas flow path R21 connects the non-welded area R12a and the outside of the laminated outer body 12C. The opening and closing valve 222 opens and closes the gas flow path R21. The opening and closing valve 222 has a cover 2221 and a spring 2222.

[0138] If the pressure inside the laminated outer casing 12C exceeds the threshold value, the mechanism 2C switches from the closed state to the open state. The "closed state" indicates a state in which the on-off valve 222 closes the gas flow path R21. The main body 221 has a partition inner wall 2210. Specifically, the closed state is a state in which the cover 2221 of the on-off valve 222 and the partition inner wall 2210 of the main body 221 are in contact. The "open state" indicates a state in which the on-off valve 222 opens the gas flow path R21. Specifically, the open state is a state in which the cover 2221 of the on-off valve 222 and the partition inner wall 2210 of the main body 221 are not in contact.

[0139] The laminated outer casing 12C is in the shape of a rectangular parallelepiped. The laminated outer casing 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 welded region R12b includes a region where the main body 221 is located between the laminated sheets 121. Figure 4As shown, the mechanism 2C is located in the imaginary area VS12 when viewed from a plane. The imaginary area VS12 is an area surrounded by a pair of first imaginary straight lines VS12a and a pair of second imaginary straight lines VS12b. The pair of first imaginary straight lines VS12a includes a pair of first sides S12a. The pair of second imaginary straight lines VS12b includes a pair of second sides S12b. Figure 5 As shown, in the Z-axis direction, the length L10 of the mechanism 2C (refer to Figure 5 ) is longer than the length L3 of the laminated outer casing 12C (refer to Figure 5 )short.

[0140] (3.2) Effects

[0141] As reference Figure 4 and Figure 5 As described above, the battery 1C includes the electrode body 11 and the laminated outer body 12C. The laminated outer body 12C includes the mechanism 2C. The mechanism 2C is located in the virtual area VS12. In the Z-axis direction, the length L10 of the mechanism 2C (see Figure 5 ) is longer than the length L3 of the laminated outer casing 12C (refer to Figure 5 )short.

[0142] Thus, the battery 1C can release the gas inside the battery 1C to the outside when the internal pressure of the battery 1C rises excessively. As a result, the occurrence of rupture of the laminated outer casing 12C of the battery 1C is suppressed. The battery 1C has excellent safety. When the battery 1C is housed in a housing to form a module, it is not necessary to ensure the conventional valve device housing space in the housing. As a result, the battery 1C can improve the volume efficiency of the module.

[0143] As reference Figure 4 and Figure 5 As described above, the mechanism 2C includes two check valves 22. The check valve 22 includes a main body 221 and an opening and closing valve 222. The welding area R12b includes an area where the main body 221 is located between the laminated sheets 121. The closed state indicates a state where the opening and closing valve 222 closes the gas flow path R21. The open state indicates a state where the opening and closing valve 222 opens the gas flow path R21.

[0144] The check valve 22 can be restored from the open state to the closed state. Therefore, even if the internal pressure of the battery 1C rises excessively two or more times, the battery 1C can be reused.

[0145] (4) Modification

[0146] In the battery 1A, the laminated outer casing 12A has two mechanisms 2A (i.e., the cover 21 that blocks the through hole TH121), but the present disclosure is not limited thereto. The laminated outer casing 12A may have one mechanism 2A, or may have three or more mechanisms 2A. The laminated outer casing 12A may also have at least one of one or more mechanisms 2B and one or more mechanisms 2C in addition to the mechanism 2A.

[0147] In the battery 1B, the laminated outer casing 12B has four mechanisms 2B (i.e., the narrow area R12b2), but the present disclosure is not limited thereto. The laminated outer casing 12B may also have 1 to 3 mechanisms 2B, or may have 5 or more mechanisms 2B. The laminated outer casing 12B may also have at least one of one or more mechanisms 2A and one or more mechanisms 2C in addition to the mechanism 2B.

[0148] In the battery 1C, the laminated outer casing 12C has two mechanisms 2C (i.e., check valves), but the present disclosure is not limited thereto. The laminated outer casing 12B may also have one mechanism 2C, or may have three or more mechanisms 2C. The laminated outer casing 12C may also have at least one of one or more mechanisms 2A and one or more mechanisms 2B in addition to the mechanism 2C.

[0149] In batteries 1A to 1C, the electrode body 11 has a stacked structure, but the present disclosure is not limited thereto. The electrode body of the present disclosure may also have a wound structure.

[0150] The laminated outer casings 12A to 12C are of a single cup structure (see Figure 2 ), but the present disclosure is not limited to this. In the present disclosure, the laminated outer casing 12A to 12C may also be a double cup structure. "Double cup structure" means a laminated outer casing having a bending line, a first cup portion (recessed portion) capable of accommodating a portion of the electrode body, and a second cup portion (recessed portion) capable of accommodating a portion of the electrode body, and being able to accommodate the entire electrode body in a space formed by the first cup portion and the second cup portion overlapping each other by bending along the bending line.

[0151] In the batteries 1A to 1C, the positive electrode tab 13 protrudes from the laminated outer casings 12A to 12C in the positive direction of the Y axis, and the negative electrode tab 14 protrudes from the laminated outer casings 12A to 12C in the negative direction of the Y axis, but the present disclosure is not limited thereto. In the present disclosure, the positive electrode tab 13 and the negative electrode tab 14 may also protrude from the laminated outer casings 12A to 12C in the positive direction of the Y axis or the negative direction of the Y axis.

Claims

1. A battery having: an electrode body; and A laminated outer package is provided to accommodate the electrode assembly therein. The laminated outer casing has a mechanism capable of switching between a closed state in which the interior is sealed and an open state in which the interior is opened to the outside of the laminated outer casing, When the pressure inside the laminated outer casing exceeds a threshold value, the mechanism switches from the closed state to the open state. The laminated outer body is in the shape of a rectangular parallelepiped, The laminated outer casing 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 when viewed in a 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 when viewed from the plane. In a third direction perpendicular to the first direction and the second direction, the length of the mechanism is shorter than the length of the laminated exterior body.

2. The battery according to claim 1, The laminated outer body is composed of a laminated sheet, The laminated outer casing has: a non-welded region where the laminated sheets are not welded to each other; and The non-welded area is sealed and the laminated sheets are welded to each other. The non-welding area comprises: a receiving area for receiving the electrode body; and The middle area is located between the receiving area and the welding area. The intermediate region comprises: at least one through hole penetrating the laminate; and A cover portion is welded to the laminate sheet to block the through hole. The thickness of the cover portion is thinner than the thickness of the laminated sheet, The mechanism includes the cover portion that blocks the through hole, The closed state means that the cover is not torn. The open state indicates a state in which the cover portion is torn.

3. The battery according to claim 1, The laminated outer body is composed of a laminated sheet, The laminated outer casing has: a non-welded region where the laminated sheets are not welded to each other; and The non-welded area is sealed and the laminated sheets are welded to each other. The non-welding area includes a receiving area for receiving the electrode body. The fusion zone has: The main part has a weld width of a specific width; and At least one narrow portion has a weld width that is shorter than the specific width. The mechanism includes the narrow part, The closed state means that the laminated sheets are fused to each other at the narrow portion. The open state indicates a state in which the laminated sheets are separated from each other at the narrow portion.

4. The battery according to claim 1, The laminated outer body is composed of a laminated sheet, The laminated outer casing has: a non-welded region where the laminated sheets are not welded to each other; and The non-welded area is sealed and the laminated sheets are welded to each other. The non-welding area includes a receiving area for receiving the electrode body. The mechanism comprises at least one check valve, The check valve comprises: a main body portion forming a gas flow path connecting the non-welded region and the outside of the laminated outer casing; and The on-off valve is used to open and close the gas flow path. The fusion region includes a region where the main body is located between the laminated sheets. The closed state indicates a state in which the on-off valve closes the gas flow path. The open state indicates a state in which the on-off valve opens the gas flow path.

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