Battery

Abstract

To provide a battery with suitably improved reliability.SOLUTION: A battery 100 disclosed herein includes an electrode body 20 having a positive electrode 22 and a negative electrode 24, an exterior body 12 having an opening 12h and housing the electrode body 20, and a sealing plate 14 that seals the opening 12h. A gas exhaust hole 17 that is a through hole that exists along the thickness direction Z exists in the sealing plate 14, and a resin member 16 that seals the gas exhaust hole 17 is disposed around the periphery of the gas exhaust hole 17. Here, the resin member 16 is configured to break when the internal pressure of the battery 100 rises above a predetermined value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] In recent years, batteries such as lithium-ion secondary batteries have been suitably used as portable power sources for personal computers, mobile terminals, etc., and as power sources for driving vehicles such as electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). Such batteries have, for example, a safety valve for releasing the internal pressure of the battery when the internal pressure of the battery rises above a predetermined value. For example, Patent Documents 1 and 2 listed below disclose such batteries. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-220508 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-187774 Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the investigations of the present inventors, it has been found that there is still room for improvement in the reliability of the above-mentioned batteries. [Means for solving the problem]

[0005] The battery disclosed herein includes an electrode assembly having a positive electrode and a negative electrode, an exterior body having an opening and housing the electrode assembly, and a sealing plate sealing the opening, the exterior body and / or the sealing plate having a gas exhaust hole that is a through hole extending along the thickness direction, and a resin member sealing the gas exhaust hole disposed on at least a portion of the periphery and / or inner wall of the gas exhaust hole, the resin member being configured to rupture when the internal pressure of the battery rises above a predetermined value. As will be described in detail later, a battery with such a configuration can be obtained with favorably improved reliability. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view schematically illustrating a battery according to an embodiment. [Figure 2] FIG. 2 is a schematic longitudinal sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a schematic vertical cross-sectional view taken along line III-III in FIG. 2. [Figure 4] 3 is a schematic diagram showing the configuration in the vicinity of the gas discharge hole in FIG. 2. FIG. [Figure 5] 5 is an explanatory diagram for explaining the configuration of the resin member in FIG. 4. FIG. [Figure 6] FIG. 10 is a view corresponding to FIG. 4 according to the second embodiment. [Figure 7] FIG. 10 is a view corresponding to FIG. 4 according to the third embodiment. [Figure 8] FIG. 10 is a view corresponding to FIG. 4 according to the fourth embodiment. [Figure 9] FIG. 10 is a view corresponding to FIG. 4 according to the fifth embodiment. [Figure 10] FIG. 11 is a view corresponding to FIG. 1 according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, some preferred embodiments of the technology disclosed herein will be described with reference to the drawings. It should be noted that matters necessary for implementing the present disclosure other than those specifically mentioned in this specification (e.g., the general configuration and manufacturing process of a battery that do not characterize the present disclosure) can be understood as design matters for those skilled in the art based on the prior art in the relevant field. The present disclosure can be implemented based on the contents disclosed in this specification and the technical common sense in the relevant field. Furthermore, the embodiments described herein are, of course, not intended to particularly limit the present disclosure. Furthermore, the expression "A to B" indicating a range in this specification is intended to include the meaning of "greater than A" and "smaller than B" as well as the meaning of "greater than A" and "smaller than B."

[0008] In this specification, the term "battery" refers to any power storage device capable of extracting electrical energy, and is a concept that encompasses primary batteries and secondary batteries. Furthermore, in this specification, the term "secondary battery" refers to any power storage device that can be repeatedly charged and discharged by the movement of charge carriers between a positive electrode and a negative electrode via an electrolyte. The electrolyte may be any of a liquid electrolyte (electrolytic solution), a gel electrolyte, and a solid electrolyte. Such secondary batteries include so-called storage batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, as well as capacitors (physical batteries) such as electric double layer capacitors. Below, an embodiment focusing on a lithium-ion secondary battery will be described.

[0009] FIG. 1 is a perspective view schematically illustrating a battery according to this embodiment. FIG. 2 is a schematic longitudinal cross-sectional view taken along line II-II in FIG. 1. In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom. In addition, the symbol X in the drawings indicates the "short side direction of the battery," the symbol Y indicates the "long side direction of the battery," and the symbol Z indicates the "height direction of the battery." However, these directions are merely used for the convenience of explanation and do not limit the installation form of the battery 100 in any way.

[0010] As shown in Figures 1 and 2, the battery 100 includes a battery case 10, an electrode assembly 20, a positive electrode terminal 30, a negative electrode terminal 40, and an insulating member 50. The positive electrode terminal 30 and / or the negative electrode terminal 40 are examples of electrode terminals. Although not shown, the battery 100 further includes an electrolyte. The battery 100 is preferably a secondary battery, and more preferably a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery.

[0011] The battery case 10 includes an exterior body 12 and a sealing plate 14. The exterior body 12 and the sealing plate 14 are examples of case members that make up the battery case 10. Here, the battery case 10 has a flattened rectangular parallelepiped (square) outer shape. The battery case 10 is integrated, for example, by joining (e.g., welding) the sealing plate 14 to the periphery of an opening 12h (see FIG. 2) of the exterior body 12. The exterior body 12 and the sealing plate 14 are formed, for example, from aluminum or an aluminum alloy.

[0012] The exterior body 12 is a housing that contains the electrode assembly 20 and the electrolyte. The exterior body 12 is a bottomed, square-shaped container having an opening 12h on its top surface. The opening 12h is generally rectangular. As shown in FIG. 2, the exterior body 12 includes a bottom wall 12a, a pair of long side walls 12b extending from the bottom wall 12a and facing each other, and a pair of short side walls 12c extending from the bottom wall 12a and facing each other. The bottom wall 12a is generally rectangular. The bottom wall 12a faces the opening 12h.

[0013] The sealing plate 14 is a plate-shaped member that seals the opening 12h of the exterior body 12. The sealing plate 14 has a substantially rectangular shape in a plan view. The size of the sealing plate is not particularly limited and can be changed appropriately depending on the desired battery capacity, etc. The sealing plate 14 faces the bottom wall 12a of the exterior body 12. As shown in FIG. 2, the sealing plate 14 has an outer surface 14A that faces the outside and is located outside the battery case 10 when the opening 12h is sealed, and an inner surface 14B that faces the inside of the battery 100 and faces the electrode assembly 20. The sealing plate 14 also has terminal mounting holes 18 and 19 that penetrate the outer surface 14A and the inner surface 14B (see FIG. 2). The terminal mounting holes 18 and 19 are provided at both ends of the sealing plate 14 in the long side direction Y. Here, terminal mounting hole 18 is for a positive electrode terminal 30, and terminal mounting hole 19 is for a negative electrode terminal 40. Sealing plate 14 is provided with a gas release valve 17 and an injection hole 13 for injecting the electrolyte. Injection hole 13 is sealed with sealing member 15.

[0014] The battery case 10 can accommodate an electrolyte solution together with the electrode assembly 20 as described above. Any electrolyte solution used in conventionally known batteries can be used without any particular limitation. As an example, a non-aqueous electrolyte solution in which a supporting salt is dissolved in a non-aqueous solvent can be used. Examples of non-aqueous solvents include carbonate-based solvents such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Examples of supporting salts include fluorine-containing lithium salts such as LiPF6.

[0015] As shown in FIG. 2 , the electrode assembly 20 is housed inside the exterior housing 12. The electrode assembly 20 is housed inside the exterior housing 12 while covered, for example, with an insulating film (not shown). Here, the electrode assembly 20 is a wound electrode assembly in which a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked in an insulated state via two strip-shaped separators 70, and wound in the long side direction around the winding axis. However, the electrode assembly 20 may also be a stacked electrode assembly in which rectangular positive electrodes and rectangular negative electrodes are alternately stacked with rectangular separators interposed therebetween. Alternatively, the electrode assembly 20 may be a zigzag-folded stacked electrode assembly formed by sandwiching multiple positive electrodes and multiple negative electrodes between zigzag-folded separators.

[0016] The positive electrode 22 includes a strip-shaped positive electrode current collector 22c and a positive electrode active material layer 22a fixed to at least one surface of the positive electrode current collector 22c. The components constituting the positive electrode 22 may be made of conventionally known materials that can be used in general batteries (e.g., lithium-ion secondary batteries) without any particular restrictions. For example, the positive electrode current collector 22c is preferably made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The positive electrode active material layer 22a contains a positive electrode active material (e.g., a lithium transition metal composite oxide such as a lithium-nickel-cobalt-manganese composite oxide) that can reversibly store and release charge carriers. The positive electrode active material layer 22a may also contain optional components other than the positive electrode active material, such as a conductive material, a binder, or various additives.

[0017] The negative electrode 24 includes a strip-shaped negative electrode current collector 24c and a negative electrode active material layer 24a fixed to at least one surface of the negative electrode current collector 24c. The components constituting the negative electrode 24 may be made of conventionally known materials that can be used in general batteries (e.g., lithium-ion secondary batteries) without any particular restrictions. For example, the negative electrode current collector 24c is preferably made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel. The negative electrode active material layer 24a contains a negative electrode active material (e.g., a carbon material such as graphite) that can reversibly store and release charge carriers. The negative electrode active material layer 24a may also contain optional components other than the negative electrode active material, such as a conductive material, a binder, a dispersant, or various additives.

[0018] The separator 70 is an insulating sheet having a plurality of fine through-holes formed therein through which charge carriers can pass. The separator 70 is made of, for example, a porous resin substrate. Examples of the resin substrate include sheets (films) made of resins such as polyolefins such as polyethylene (PE) and polypropylene (PP), polyesters, polyamides, and cellulose. The separator 70 may have a single-layer structure, or may have a laminated structure of two or more porous resin sheets having different properties and characteristics (thickness, porosity, etc.) (for example, a three-layer structure in which PP layers are laminated on both sides of a PE layer). The separator 70 may also have a heat-resistant layer (HRL) made of ceramic particles or the like on its surface.

[0019] As shown in FIG. 2, the electrode assembly 20 housed inside the exterior housing 12 is arranged so that one end of the positive electrode current collector 22c is near the left end of the battery 100 in the long side direction Y, and one end of the negative electrode current collector 24c is near the right end of the battery 100 in the long side direction Y. The positive electrode terminal 30 is attached to one end of the sealing plate 14 in the long side direction Y (the left end in FIG. 2). The negative electrode terminal 40 is attached to the other end of the sealing plate 14 in the long side direction Y (the right end in FIG. 2). In the battery 100, one end of the positive electrode terminal 30 and the negative electrode terminal 40 is electrically connected to the electrode assembly 20 inside the battery case 10 as described above, and the other end is inserted into the terminal mounting holes 18, 19 and exposed to the outside of the sealing plate 14. The positive electrode terminal 30 is preferably formed of a metal with excellent conductivity, such as aluminum or an aluminum alloy. The negative electrode terminal 40 is preferably made of a metal with excellent electrical conductivity, such as copper or a copper alloy.

[0020] Fig. 3 is a schematic longitudinal cross-sectional view taken along line III-III in Fig. 1. As shown in Fig. 3, the negative electrode terminal 40 has a negative electrode external connection portion 41, an electrode assembly connection portion 42, and a shaft portion 43. Here, the negative electrode terminal 40 further has a seat portion 44 between the electrode assembly connection portion 42 and the shaft portion 43. However, the negative electrode external connection member 41 is not essential and may be omitted in other embodiments.

[0021] The insulating member 50 is disposed between the sealing plate 14 and the negative electrode terminal 40 and prevents electrical conduction between the sealing plate 14 and the negative electrode terminal 40. The insulating member 50 is typically made of a resin material. Examples of the resin material include fluorinated resins such as perfluoroalkoxy fluorine resin (PFA), polyphenylene sulfide resin (PPS), and aliphatic polyamide. In addition to the resin material such as PPS, an inorganic filler may be added to the insulating member 50. The insulating member 50 includes an external insulating member 51 that insulates the negative electrode external connection portion 41 from the sealing plate 14, and an internal insulating member 52 that insulates the electrode assembly connection portion 42 and the base portion 44 from the sealing plate 14.

[0022] The electrode assembly connection portion 42 is disposed inside the battery case 10 and is electrically connected to the electrode assembly 20. As shown in FIG. 3, the electrode assembly connection portion 42 is formed in a plate shape, bent at a substantially right angle from the rear end of the base portion 44, and extends downward. The electrode assembly connection portion 42 extends toward the bottom wall 12a. The electrode assembly connection portion 42 also bends toward the front side at its middle portion. Below the bent portion, the electrode assembly connection portion 42 extends again toward the bottom wall 12a. Due to this bending, the tip of the electrode assembly connection portion 42 is located in the center of the base portion 44 in the direction of the short side.

[0023] The shaft portion 43 is located between the external connection portion 41 and the electrode body connection portion 42 and is inserted into the terminal mounting hole 19. The shaft portion 43 extends upward from the base portion 44. As shown in FIG. 3 , the shaft portion 43 is located approximately in the center of the base portion 44 in the short side direction X. The length of the shaft portion 43 in the short side direction X is shorter than the lengths of the base portion 44 and the terminal mounting hole 19 in the short side direction X. Although not shown, the length of the shaft portion 43 in the long side direction Y is shorter than the lengths of the base portion 44 and the terminal mounting hole 19 in the long side direction Y. Therefore, the shaft portion 43 is spaced apart from the inner circumferential surface of the terminal mounting hole 19. Due to the difference in size between the external connection portion 41, the shaft portion 43, and the base portion 44, the shaft portion 43 is constricted relative to the external connection portion 41 and the base portion 44.

[0024] The base portion 44 is located between the electrode assembly connecting portion 42 and the shaft portion 43. The base portion 44 is a plate-shaped member extending horizontally along the inner surface 14B of the sealing plate 14. As shown in FIG. 3, the length of the base portion 44 in the short side direction X is longer than the length of the terminal mounting hole 19 in the short side direction X. Although not shown, the length of the base portion 44 in the long side direction Y is longer than the length of the terminal mounting hole 19 in the long side direction Y. The base portion 44 has a larger radial size than the terminal mounting hole 19. Although not described here, the positive electrode side has a similar configuration. In addition, 32 in FIG. 2 denotes the electrode assembly connecting portion.

[0025] Next, the vicinity of the gas exhaust hole 17, which characterizes the battery 100 according to this embodiment, will be described. Here, FIG. 4 is a schematic diagram showing the configuration of the vicinity of the gas exhaust hole in FIG. 2. As described above, the battery 100 includes an electrode assembly 20 having a positive electrode 22 and a negative electrode 24, an exterior body 12 having an opening 12h and housing the electrode assembly 20, and a sealing plate 14 that seals the opening 12h. In this embodiment, the sealing plate 14 has a gas exhaust hole 17, which is a through-hole extending along the thickness direction Z. As shown in FIG. 4, in this embodiment, a resin member 16 that seals the gas exhaust hole 17 is disposed around the periphery of the gas exhaust hole 17 (here, the periphery of the gas exhaust hole 17 on the inner surface 14B side of the sealing plate 14). The resin member 16 is configured to rupture when the internal pressure of the battery 100 exceeds a predetermined value.

[0026] For example, using a metal safety valve is undesirable because it has the same heat resistance as parts other than the safety valve (specifically, the metal sealing plate and exterior body), which could lead to unexpected side ruptures in the event of a battery malfunction. In contrast, the battery 100 disclosed herein has a resin safety valve that is more likely to become embrittled at high temperatures than a metal safety valve, allowing it to rupture preferentially in the event of a battery malfunction. Furthermore, for example, a metal safety valve may develop unintended protrusions (burrs) during molding, which could cause a short circuit if the burrs come into contact with the internal electrode. In contrast, the battery 100, for example, has a resin safety valve that is less likely to develop burrs during molding, and even if burrs do develop, the aforementioned short circuit does not occur. Therefore, a battery 100 with favorably improved reliability can be obtained.

[0027] Furthermore, as the capacity of batteries increases, the thickness of the sealing plate and the exterior body tends to increase to ensure strength, but in such cases, it may become difficult to process thin-film portions such as safety valves, which is undesirable. In contrast, with battery 100, for example, resin member 16 can be disposed on either the inside or outside of sealing plate 14 or exterior body 12, allowing for greater flexibility in molding. Therefore, battery 100 can be obtained with excellent processability.

[0028] FIG. 5 is an explanatory diagram illustrating the configuration of the resin member of FIG. 4. As can be seen from FIG. 5, in this embodiment, the shape of the resin member 16 in a plan view is elliptical. For example, if the resin member 16 is elliptical or circular, it is preferable because force is more easily applied uniformly and the breaking strength of the resin member 16 is stable. However, in other embodiments, the shape of the resin member 16 may be various shapes such as rectangular, triangular, or star-shaped. Alternatively, the resin member 16 may be provided so as to cover the entire surface of the sealing plate 14. In such a case, it is preferable because short-circuiting between the sealing plate 14 and the electrode body 20 can be effectively prevented.

[0029] The size of the resin member 16 is not particularly limited as long as the effects of the technology disclosed herein are achieved. The lower limit of the thickness P of the resin member 16 is, for example, 1 / 5 or more, or even 1 / 4 or more, of the thickness of the sealing plate 14 (when the resin member 16 is disposed in the exterior body 12, the thickness of the exterior body 12). The upper limit of the thickness P of the resin member 16 is, for example, 1 or less, or 1 / 2 or less, or 1 / 3 or less, of the thickness of the sealing plate 14 (when the resin member 16 is disposed in the exterior body 12, the thickness of the exterior body 12). The thickness P of the resin member 16 can be within a range of 5 mm to 10 mm (e.g., 6 mm to 8 mm). However, it is not intended to be limited to this range. The thickness P of the resin member 16 is preferably determined appropriately depending on the type of resin material constituting the resin member 16, etc.

[0030] As shown in FIG. 4 , in this embodiment, the resin member 16 has multiple (here, two) notches 16 a on the outer surface side of the battery 100. The notches 16 a can also be referred to as cuts, notches, or grooves. This configuration provides a partially weakened portion in the resin member 16, thereby enabling the break strength of the resin member 16 to be suitably adjusted. The number of notches may be one, or three or more. In this embodiment, the shape of the notch 16 a is V-shaped, but this is not limited thereto. In other embodiments, the shape of the notch 16 a may be U-shaped or various other shapes. The notch 16 a can be formed in advance in the resin member 16 using a tool such as a file. For example, when integral molding is performed as described below, the notch 16 a can also be formed using a mold.

[0031] The size (depth) Q of the notch 16a in the Z direction is not particularly limited as long as the effects of the technology disclosed herein are achieved. The lower limit of the depth Q of the notch 16a is, for example, 1 / 10 or more, 1 / 5 or more, or 1 / 4 or more of the thickness P of the resin member 16, from the viewpoint of making the resin member 16 easier to break. The upper limit of the depth Q of the notch 16a is, for example, 1 / 2 or less, or 1 / 3 or less of the thickness P of the resin member 16, from the viewpoint of suitably ensuring the strength of the resin member 16. The depth Q of the notch 16a can be within a range of 1 mm to 5 mm (e.g., 2 mm to 4 mm). However, this is not intended to be a limitation. The depth Q of the notch 16a is preferably determined appropriately depending on the type of resin material constituting the resin member 16.

[0032] The resin material constituting the resin member 16 is not particularly limited as long as it exhibits the effects of the technology disclosed herein. Suitable examples of such resin materials include fluorine-based resins such as PFA resin (perfluoroalkoxy fluororesin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer) resin, ETFE (ethylene-tetrafluoroethylene copolymer) resin, and PTFE (polytetrafluoroethylene) resin; PP (polypropylene) resin; and PPS (polyphenylene sulfide) resin. Such resin materials are preferred because they provide a good balance between heat resistance and chemical resistance (e.g., chemical resistance to electrolyte). The resin member 16 may be made of one or a combination of two or more of these resins.

[0033] In this embodiment, the resin member 16 and the sealing plate 14 are provided in the battery 100 as an integrally molded product (also referred to as an insert-molded product). In other words, the resin member 16 and the sealing plate 14 are integrally molded. This configuration is preferable from the standpoint of cost, etc. As will be described in detail later, in this embodiment, in addition to the resin member 16, the positive electrode terminal 30, the negative electrode terminal 40, and the insulating member 50 are integrally molded with the sealing plate 14. Furthermore, as shown in FIG. 4 , to further enhance the bonding strength between the resin member 16 and the sealing plate 14, at least a portion of the bonding portion of the sealing plate 14 with the resin member 16 may be roughened in advance. Such roughening can be performed, for example, by filing or laser etching. The cross in FIG. 4 indicates the roughened portion of the sealing plate 14. Note that such roughening is not essential, and in other embodiments, roughening may not be performed.

[0034] The breaking strength of resin member 16 can be adjusted, for example, by changing the size of gas exhaust holes 17 in sealing plate 14. It can also be adjusted, for example, by changing the configuration of resin member 16 (e.g., the type and thickness of the resin material) or the number of notches 16a. Alternatively, when sealing plate 14 is roughened in advance, it can also be adjusted by changing the roughened area, etc. Those skilled in the art can easily adjust the breaking strength of resin member 16 by, for example, conducting preliminary experiments based on this information.

[0035] <Battery manufacturing method> The battery 100 as described above can be manufactured by a manufacturing method including, for example, (1) a preparation step and (2) a laser welding step. Here, the preparation step further includes (1A) an insert molding step.

[0036] (1) In the preparation step, the battery case 10 and the sealing plate 14 are prepared. In addition, the other necessary components as described above are prepared.

[0037] (1A) In the insert molding process, the sealing plate 14 is integrated with the positive electrode terminal 30, the negative electrode terminal 40, the insulating member 50, and the resin member 16 having a plurality of (here, two) notches 16a to produce an assembly part (hereinafter also referred to as "sealing plate assembly"). The sealing plate assembly can be produced by insert molding the sealing plate 4, the positive electrode terminal 30, the negative electrode terminal 40, the insulating member 50, and the resin member 16. This reduces the number of parts and is easier to manufacture than conventional methods. The conductive path can be formed more easily than with insert molding. Insert molding can be performed according to a conventionally known method, as described in, for example, JP 2021-086813 A, JP 2021-086814 A, Japanese Patent No. 3986368 A, Japanese Patent No. 6648671 A, etc. For example, the insert molding can be performed using a molding die having a lower die and an upper die, by a method including a part setting step, a positioning step, an upper die setting step, an injection molding step, an upper die release step, and a part removal step.

[0038] In the component setting process, the positive electrode terminal 30 and the negative electrode terminal 40 are inserted into the terminal mounting holes 18, 19 of the sealing plate 4, and then the sealing plate 4 is attached to the lower mold. In the positioning process, the positive electrode terminal 30 and the negative electrode terminal 40 are positioned and fixed. In the upper mold setting process, the upper mold is attached together with the lower mold so that the sealing plate 14 and the positive electrode terminal 30 and the negative electrode terminal 40 are sandwiched between them in the vertical direction. In the injection molding process, first, the molding die is heated. Next, molten resin is injected into the molding die. The molten resin flows from the upper mold through the terminal mounting holes 18, 19 and into the lower mold. The molten resin also flows from the upper mold through the gas exhaust hole 17 and into the lower mold. Then, the molding die and the molded product are cooled. This integrates the insulating member 50, the sealing plate 14, the positive electrode terminal 30, the negative electrode terminal 40, and the resin member 16. In the upper die release step, the upper die is separated from the lower die, and in the part removal step, the molded product is removed from the lower die.

[0039] (2) In the laser welding process, after the electrode body 20 is housed inside the battery case 10, the sealing plate 14 is fitted into the opening 12h of the battery case 10. Next, the seam (fitting portion) between the battery case 10 and the sealing plate 14 is welded with a laser. The type of laser beam used for laser welding and the laser welding conditions may be the same as conventional ones and are not particularly limited. By welding the fitting portion around the entire periphery, the sealing plate 14 and the battery case 10 are welded without any gaps. Then, electrolyte is injected through the liquid inlet 13, and the liquid inlet 13 is closed with a sealing member to hermetically seal the battery 100. In this manner, the battery 100 can be manufactured.

[0040] Battery 100 can be used for a variety of purposes, but can be suitably used, for example, as a power source (driving power source) for motors mounted on vehicles such as passenger cars and trucks. The type of vehicle is not particularly limited, but examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). Battery 100 can also be used as a battery pack having a plurality of batteries 100.

[0041] Although one embodiment of the present disclosure has been described above, the above embodiment is merely an example. The present disclosure can be implemented in various other forms. The present disclosure can be implemented based on the contents disclosed in this specification and the common general technical knowledge in the relevant field. The technology described in the claims includes various modifications and alterations of the above-exemplified embodiment. For example, it is possible to replace part of the above-described embodiment with other modified embodiments, and it is also possible to add other modified embodiments to the above-described embodiment. Furthermore, if a technical feature is not described as essential, it can be deleted as appropriate.

[0042] For example, Fig. 6 is a view corresponding to Fig. 4 according to the second embodiment. As shown in Fig. 6, in the second embodiment, a resin member 116 that seals the gas exhaust hole 117 is disposed on the periphery and inner wall of the gas exhaust hole 117 of the sealing plate 114. The battery according to the second embodiment may be similar to the battery 100 described above, except that the arrangement of the resin member 116 is changed from that of the resin member 16.

[0043] For example, Fig. 7 is a view corresponding to Fig. 4 according to the third embodiment. As shown in Fig. 7, in the third embodiment, a resin member 316 that seals gas discharge hole 317 is arranged around the periphery of gas discharge hole 317 in sealing plate 314 (here, around the periphery of gas discharge hole 317 on the inner surface side of sealing plate 314). The battery according to the third embodiment may be similar to battery 100 described above, except that the arrangement of resin member 316 is changed from that of resin member 16.

[0044] For example, Fig. 8 is a view corresponding to Fig. 4 according to the fourth embodiment. As shown in Fig. 8, in the fourth embodiment, a resin member 416 that seals a gas exhaust hole 417 is disposed on the inner wall of the gas exhaust hole 417 of a sealing plate 414. The battery according to the fourth embodiment may be similar to the battery 100 described above, except that the arrangement of the resin member 416 is changed from that of the resin member 16.

[0045] For example, Fig. 9 is a view corresponding to Fig. 4 according to a fifth embodiment. As shown in Fig. 9, in the fifth embodiment, a resin member 516 that seals a gas discharge hole 517 is disposed around the periphery of a gas discharge hole 517 in a sealing plate 514 (here, the periphery of the gas discharge hole 517 on the outer surface side of the sealing plate 514). The battery according to the fifth embodiment may be similar to the battery 100 described above, except that the arrangement of the resin member 516 is changed from that of the resin member 16.

[0046] For example, FIG. 10 is a view corresponding to FIG. 1 according to a sixth embodiment. As shown in FIG. 10, in the sixth embodiment, gas exhaust holes 217A and 217B, which are through-holes extending along the thickness direction X, are present in the exterior body 212 of the battery 200. Although not shown in detail, in the sixth embodiment, resin members 216A and 216B that seal the gas exhaust holes 217A and 217B are disposed on the inner walls of the gas exhaust holes 217A and 217B. The battery 200 according to the sixth embodiment may be similar to the battery 100 described above, except that the arrangement of the resin members 216A and 216B is changed from the resin member 16. The arrangement of the resin members 216A and 216B can be changed as described in the first to third and fifth embodiments. In the sixth embodiment, the resin member 216A is disposed above the second side wall 212c, and the resin member 217B is disposed at the center of the first side wall 212b. However, the positions of the resin members 216A and 216B are not limited to these. The positions of the resin members 216A and 216B can be changed as long as the effects of the technology disclosed herein are achieved. In addition, although the resin members are formed on both the first side wall 212b and the second side wall 212c of the exterior body 12, the resin member is not limited to this. In other embodiments, the resin member may be formed only on the first side wall 212b of the exterior body 212, or may be formed only on the second side wall 212c. Furthermore, the resin member may be formed on the first side wall 212b and / or the second side wall 212c, and further, the resin member may be formed on the sealing plate. Here, 210, 213, 214, 215, 230, and 240 in FIG. 10 correspond to 10, 13, 14, 15, 30, and 40 in FIG. 1, respectively.

[0047] With regard to the second to sixth embodiments, the description of the resin member 16 above can be referred to for the configuration (e.g., type, size, shape, etc. of the resin material) and formation method of the resin members 117, 216A, 216B, 316, 416, and 516. Appropriate notches can also be formed in the resin members according to the second to sixth embodiments. The description of the notch 16a above can be referred to for such notches. The sealing plates according to the second to fifth embodiments and the exterior body according to the sixth embodiment may also be subjected to a surface roughening treatment in advance, in order to suitably improve the bonding strength, as in the above-described embodiments.

[0048] For example, in the above embodiment, the resin member 16 and the sealing plate 14 are integrally molded, but this is not limiting. For example, in other embodiments, the resin member 16 can be joined to the sealing plate 14 by heat welding. Conventionally known methods can be used as the heat welding method. In such a case, the sealing plate 14 may be subjected to a surface roughening treatment in advance in order to suitably improve the bonding strength.

[0049] As described above, specific aspects of the technology disclosed herein include those described in the following items. Item 1: A battery comprising an electrode assembly having a positive electrode and a negative electrode, an exterior body having an opening and housing the electrode assembly, and a sealing plate that seals the opening, wherein the exterior body and / or the sealing plate have a gas discharge hole that is a through-hole that runs along the thickness direction, and a resin member that seals the gas discharge hole is disposed on at least a portion of the periphery and / or inner wall of the gas discharge hole, and wherein the resin member is configured to rupture when the internal pressure of the battery rises above a predetermined value. Item 2: The battery according to item 1, wherein the resin member has a circular or elliptical shape in a plan view. Item 3: The battery according to item 1 or 2, wherein the resin member has one or more notches on the outer surface side of the battery. Item 4: The battery according to any one of items 1 to 3, wherein the resin member includes at least one selected from the group consisting of a fluorine-based resin, a polypropylene resin, and a polyphenylene sulfide resin. Item 5: The battery according to any one of items 1 to 4, wherein the resin member, the exterior body, and / or the sealing plate are provided as an integrally molded product. [Explanation of symbols]

[0050] 10 Battery case 12 Exterior body 12h opening 13 Liquid injection hole 14 Sealing plate 15 Sealing member 16 Resin parts 16a notch 17 Gas exhaust hole 18, 19 Terminal mounting holes 20 Electrode body 22 Positive electrode 24 Negative electrode 30 Positive terminal 31 Positive electrode current collecting member 32 Positive external connection 40 Negative terminal 41 Negative electrode current collecting member 42 Negative external connection 50 Insulating material 70 Separator 100 batteries

Claims

1. an electrode assembly having a positive electrode and a negative electrode; an exterior body having an opening and accommodating the electrode body; a sealing plate that seals the opening; A battery comprising: a gas exhaust hole, which is a through hole extending along a thickness direction, is provided in the exterior body and / or the sealing plate; a resin member that seals the gas discharge hole is disposed on at least a portion of the periphery and / or inner wall of the gas discharge hole, wherein the resin member has one or a plurality of linear notches independent of each other on an outer surface side of the battery, and is configured to rupture when the internal pressure of the battery rises above a predetermined value; The depth of the linear notch is equal to or greater than 1 / 10 and equal to or less than 1 / 2 of the thickness of the resin member.

2. The battery according to claim 1 , wherein the resin member has a circular or elliptical shape in a plan view.

3. 3. The battery according to claim 1, wherein the resin member comprises at least one selected from the group consisting of a fluorine-based resin, a polypropylene resin, and a polyphenylene sulfide resin.

4. The battery according to claim 1 , wherein the resin member, the exterior body, and / or the sealing plate are provided as an integrally molded product.

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