Battery accommodation body, battery module, and battery pack

Abstract

A battery accommodation body 1 comprises: a housing 3 that accommodates a battery cell 2; at least one active gas removal part 4 that is disposed in the housing 3 and that removes active gas generated from the battery cell 2; and a ventilation part 5 that is provided in at least a region in which the at least one active gas removal part 4 faces the battery cell 2 and that has air permeability.

Description

Battery housing, battery module, and battery pack

[0001] The present invention relates to a battery containing body, a battery module, and a battery pack.

[0002] In recent years, development of sulfide-based solid electrolytes exhibiting high ionic conductivity has been progressing as solid electrolytes for use in all-solid-state batteries. However, sulfide-based solid electrolytes may react with water to generate hydrogen sulfide. Therefore, measures to address this hydrogen sulfide are an issue for practical application of all-solid-state batteries using sulfide-based solid electrolytes. Patent Literature 1 describes a technology in which a gas adsorption section communicating with a storage chamber containing a battery cell via at least one communication passage is provided within a housing, thereby reducing the concentration of hydrogen sulfide generated within the storage chamber and discharging it to the outside. Patent Literature 1 also describes a technology in which, in combination with the above technology, an inert gas is introduced into the storage chamber to prevent hydrogen sulfide from accumulating within the storage chamber, thereby reducing the hydrogen sulfide concentration within the storage chamber.

[0003] International Publication No. 2022 / 249671

[0004] However, the technique described in Patent Document 1 may cause the following problems.

[0005] (1) If hydrogen sulfide continues to be generated, and the location of hydrogen sulfide generation is far from the communication paths, the materials of the battery cells and their accessories (such as electrode terminals and electrical circuits) located between them may be corroded by the hydrogen sulfide. While it is possible to increase the number of communication paths, this would mean that only some of the gas adsorption sections close to the communication paths would function. This would rapidly reduce the adsorption performance of the gas adsorption sections as a whole, potentially leading to hydrogen sulfide leaks to the outside.

[0006] (2) Because gas flows only in one direction within the housing, from the storage chamber to the gas adsorption section, if hydrogen sulfide continues to be generated, the hydrogen sulfide concentration in the storage chamber will continue to rise. As a result, there is a concern that hydrogen sulfide, as a flammable gas, may react with oxygen and burn, or, as mentioned above, hydrogen sulfide, as a corrosive gas, may corrode the materials of the battery cells.

[0007] (3) The problem of (2) above can be solved by introducing an inert gas into the storage chamber, but this requires a container to store the inert gas, which leads to an increase in the size and cost of the device. Furthermore, since the inert gas introduced into the storage chamber is released to the outside, there is a risk that nearby workers may suffer from oxygen deficiency, which may increase safety risks.

[0008] Such problems may also occur when other active gases besides hydrogen sulfide are generated, and may also occur when various other active gases are generated in batteries other than all-solid-state batteries containing sulfide-based solid electrolytes. Therefore, a solution that can be applied to such a wide variety of active gases is required.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a battery containing body, a battery module, and a battery pack that are economical, safe, and reliable.

[0010] In order to achieve the above-mentioned object, the battery containing body of the present invention has a housing that contains a battery cell, an active gas removal section that is arranged within the housing and removes active gas generated from the battery cell, and a ventilation section that has breathability and is provided at least in the area where the active gas removal section faces the battery cell.

[0011] A battery module of the present invention includes the battery containing body and battery cells contained in the housing of the battery containing body.

[0012] A battery pack of the present invention includes the above battery module.

[0013] With this battery containing body, battery module, and battery pack, even if active gas is generated from the battery cells, the hydrogen sulfide can be transferred to the active gas removal section via the shortest route through the ventilation section, and gas (e.g., air) can be transferred from the active gas removal section to the space housing the battery cells. This prevents an increase in the concentration of active gas inside the housing and reduces the possibility that the active gas will have adverse effects inside the housing. Furthermore, because the entire area of ​​the active gas removal section facing the ventilation section can come into contact with hydrogen sulfide, its performance is not rapidly degraded. Furthermore, because there is no need to introduce inert gas into the housing, there is no associated increased safety risk.

[0014] As described above, according to the present invention, it is possible to provide a battery containing body, a battery module, and a battery pack that are economical, safe, and reliable.

[0015] Fig. 1 is a schematic configuration diagram of a battery module according to a first embodiment of the present invention; Fig. 2 is a schematic configuration diagram of a battery module according to a second embodiment of the present invention; Fig. 3 is a schematic configuration diagram of a battery module according to a third embodiment of the present invention; Fig. 4 is a schematic configuration diagram of a battery module according to a fourth embodiment of the present invention; and Fig. 5 is a schematic configuration diagram of a battery module according to a fifth embodiment of the present invention.

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Configurations common to each embodiment will be denoted by the same reference numerals in the drawings, and duplicated descriptions will be omitted as appropriate. Furthermore, as may be mentioned again below, characteristic configurations and modifications of each embodiment can also be applied to other embodiments as long as they are not mutually inconsistent.

[0017] In the following embodiments, an all-solid-state battery containing a sulfide-based solid electrolyte is exemplified as a battery cell that can generate an active gas, and hydrogen sulfide, which is flammable and corrosive, is exemplified as an active gas to be removed by the present invention, but the present invention is not limited thereto. In other words, the active gas to be removed by the present invention may be an active gas other than hydrogen sulfide generated by an all-solid-state battery containing a sulfide-based solid electrolyte. In this context, the term "active gas" broadly means a gas that can chemically react with other elements or compounds. Examples of such active gases include sulfur (S, S) and sulfur (S). ２ , S ８ Examples of such active gases include sulfur oxides (sulfur monoxide, sulfur dioxide, sulfur trioxide, etc.), halogens (fluorine, chlorine, bromine, iodine, etc.), oxygen, and carbon dioxide. Alternatively, the active gases may be those generated by other types of batteries, such as hydrogen, carbon dioxide, methane, ethane, ethylene, hydrogen fluoride, and carbon monoxide generated by lithium-ion batteries; fluorine and hydrogen fluoride generated by fluoride batteries; hydrogen and oxygen generated by aqueous batteries such as aqueous lithium-ion batteries and zinc-negative battery batteries; and sulfur dioxide generated by inorganic electrolyte batteries. On the other hand, the active gas targeted for removal by the present invention may be the vaporized gas of an organic solvent used in the nonaqueous electrolyte of a lithium-ion battery. Examples of such organic solvents include ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, and propyl propionate.

[0018] First Embodiment FIG. 1 is a schematic diagram of a battery module according to a first embodiment of the present invention.

[0019] The battery module 1 has a plurality of battery cells 2 and at least one pair of electrode terminals (not shown). The battery cells 2 are electrically connected to one another. The connection configuration is not particularly limited and may be in series, parallel, or a combination of these. At least some of the battery cells 2 may be restrained by a restraining member. At least one pair of electrode terminals is electrically connected to the battery cells 2 by an electrical circuit (not shown) so that power can be extracted from the battery cells 2. Although seven battery cells 2 are shown in FIG. 1 , the number of battery cells 2 included in the battery module 1 is not limited to this. A battery pack is formed by combining a plurality of battery modules 1 and housing them in a case.

[0020] The battery cell 2 is an all-solid-state battery and includes a positive electrode, a negative electrode, and a solid electrolyte layer disposed between the positive electrode and the negative electrode. For example, the positive electrode includes a positive electrode current collector and a positive electrode active material layer, and the negative electrode includes a negative electrode current collector and a negative electrode active material layer. The positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector are stacked in this order to form a laminate, which is housed in a battery case of a laminate type, a cylindrical type, a prismatic type, or the like. A reinforcing layer made of a curable resin may be provided around the laminate, if necessary.

[0021] The positive electrode current collector and the negative electrode current collector can be made of known materials commonly used in all-solid-state batteries. The positive electrode current collector can be made of metal materials such as aluminum, stainless steel, and titanium, and can be in the form of, for example, foil, film, sheet, or mesh. The negative electrode current collector can be made of metal materials such as stainless steel, nickel, and copper, and can be in the form of, for example, foil, film, or sheet.

[0022] The positive electrode active material layer contains at least a positive electrode active material, and the negative electrode active material layer contains at least a negative electrode active material. The positive electrode active material is not particularly limited as long as it is a material that absorbs and releases metal ions such as lithium ions, and examples thereof include sulfur, lithium-containing transition metal oxides, transition metal fluorides, polyanion compounds, and transition metal sulfides. The negative electrode active material is not particularly limited as long as it is a material that absorbs and releases metal ions such as lithium ions, and examples thereof include metallic lithium, metals or alloys that can be alloyed with lithium, carbon materials such as graphite and hard carbon, transition metal oxides, transition metal sulfides, and silicon. The positive electrode active material layer and the negative electrode active material layer may each contain a solid electrolyte, a binder, or the like, as appropriate.

[0023] The solid electrolyte layer contains at least a sulfide-based solid electrolyte. The sulfide solid electrolyte may be, for example, Li ２ S-SiS ２ system, Li ２ S-B ２ S ３ system, Li ２ S-P ２ S ３ system, Li ２ S-P ２ S ５ system, Li ２ S-GeS ２ system, Li ２ S-B ２ S ３ system, Li ３ P.O. ４ -P ２ S ５ system, Li ４ SiO ４ -Li ２ S-SiS ２ Glasses or glass ceramics such as Li-based ３．２５ Ge ０．２５ P ０．７５ S ４ , Li １０ GeP ２ S １２ In addition, LiCl, LiBr, LiI, Li ｘ MO ｙ(wherein M is any of P, Si, Ge, B, Al, Ga, and In, and x and y are natural numbers) may be added, and a material that has been further heat-treated may also be used. The solid electrolyte layer may contain a binder or the like as appropriate, and may contain a type of solid electrolyte different from the sulfide-based solid electrolyte. Examples of such solid electrolytes include halide-based solid electrolytes, oxide-based solid electrolytes, polymer-based solid electrolytes, hydride-based solid electrolytes, and nitride-based solid electrolytes.

[0024] The battery module 1 also has a housing 3, a hydrogen sulfide removal section (active gas removal section) 4, and a ventilation section 5, which together form a battery housing body that accommodates a plurality of battery cells 2.

[0025] The housing 3 has the function of housing multiple battery cells 2 while extending at least one pair of electrode terminals (not shown) to the outside. Inside the housing 3, fillers such as elastic materials, heat transfer materials, and heat insulating materials may be appropriately disposed in gaps between the battery cells 2 or between the battery cells 2 and the restraining members described above. While FIG. 1 shows a simplified view, considering heat dissipation from the battery cells 2, it is preferable that the multiple battery cells 2 are housed in the housing 3 with at least a portion of them in direct or indirect contact with the housing 3 (for example, via the restraining members described above). The shape of the housing 3 is not particularly limited and can be set as desired depending on the shape and arrangement of the battery cells 2 to be housed.

[0026] The hydrogen sulfide removal unit 4 is disposed below the battery cell 2 and functions to remove hydrogen sulfide (active gas) generated when the sulfide-based solid electrolyte contained in the battery cell 2 reacts with water. The hydrogen sulfide removal unit 4 is not particularly limited, and any known removal agent commonly used for removing hydrogen sulfide can be used. Examples of such removal agents include ion exchange resins, activated carbon (particularly activated carbon impregnated with a basic compound such as sodium hydroxide or potassium carbonate), activated alumina (particularly activated alumina impregnated with potassium permanganate), zeolites, basic solids such as calcium oxide or calcium carbonate, basic liquids such as aqueous sodium hydroxide or aqueous sodium carbonate, and ionic liquids having a reactive site with acids such as amino groups. Because hydrogen sulfide may reach a temperature higher than room temperature due to heat generation in the battery cell 2, a hydrogen sulfide removal agent that can maintain its hydrogen sulfide removal performance even at high temperatures is preferred, and a removal mechanism based on an irreversible reaction is more preferred. This allows hydrogen sulfide to be reliably removed even at high temperatures and suppresses the re-release of the removed hydrogen sulfide. The remover serving as the hydrogen sulfide remover 4 may be housed in a box-shaped container made of metal such as aluminum or stainless steel, with an open top, as needed.

[0027] The ventilation section 5 is a plate-like member with air permeability that is disposed between the battery cells 2 and the hydrogen sulfide removal section 4, specifically, between the storage space S in which the battery cells 2 are housed and the hydrogen sulfide removal section 4. The ventilation section 5 is not particularly limited as long as it has an air-permeable structure such as a porous or mesh structure. For example, a synthetic resin nonwoven fabric, a metal screen mesh, a punched metal, a sintered filter, or a combination thereof can be used. Note that the removing agent used in the hydrogen sulfide removal section 4 is a foreign substance and therefore may adversely affect the materials of the battery cells 2 and their accessories (such as electrode terminals and electrical circuits). Therefore, the term "air permeable" as used herein means a property that allows hydrogen sulfide-containing gas to pass through while not allowing the removing agent used in the hydrogen sulfide removal section 4 to pass through.

[0028] With this configuration, the hydrogen sulfide removal unit 4 is located below the battery cells 2 across the ventilation unit 5. Therefore, even if hydrogen sulfide is generated from the battery cells 2, the hydrogen sulfide can be transferred to the hydrogen sulfide removal unit 4 via the shortest vertical path by utilizing the difference in specific gravity between the hydrogen sulfide removal unit 4 and the gas (e.g., air) inside the casing. Accordingly, an amount of gas equivalent to the amount of hydrogen sulfide transferred to the hydrogen sulfide removal unit 4 can be transferred from the hydrogen sulfide removal unit 4 to the storage space S for the battery cells 2. This suppresses an increase in the hydrogen sulfide concentration in the storage space S, thereby reducing the possibility that hydrogen sulfide, as a flammable gas, will react with oxygen in the casing 3 and burn, or that hydrogen sulfide, as a corrosive gas, will corrode the materials of the battery cells 2. Furthermore, the entire area of ​​the hydrogen sulfide removal unit 4 facing the ventilation unit 5 can come into contact with hydrogen sulfide. This prevents the hydrogen sulfide removal unit 4 from functioning only partially, and prevents its performance from rapidly deteriorating. Furthermore, there is no need to introduce an inert gas to suppress an increase in the hydrogen sulfide concentration in the storage space S. Therefore, there is no risk of the device becoming larger or the costs increasing, and there is no risk of increased safety risks due to the emission of inert gas.

[0029] In the illustrated example, the hydrogen sulfide removal unit 4 is disposed below the storage space S for the battery cells 2, but the location of the hydrogen sulfide removal unit 4 is not particularly limited as long as it can remove hydrogen sulfide generated from the battery cells 2. For example, the hydrogen sulfide removal unit 4 may be disposed between the battery cells 2, or may be disposed around (to the side or above) the battery cells 2. In this case, too, diffusion due to concentration differences can be utilized to move hydrogen sulfide to the hydrogen sulfide removal unit 4 via the shortest route. However, it is preferable that the hydrogen sulfide removal unit 4 be disposed below the storage space S for the battery cells 2 as illustrated, because this can utilize not only diffusion due to concentration differences but also sedimentation due to differences in specific gravity with the surrounding area, thereby allowing hydrogen sulfide to reach the hydrogen sulfide removal unit 4 more quickly.

[0030] To further increase the settling rate due to the difference in specific gravity, the interior of the casing 3 may be pre-filled with an inert gas having a lower specific gravity than hydrogen sulfide, such as nitrogen, argon, or helium. Filling the casing 3 with such an inert gas is also preferable because it reduces the moisture and oxygen concentrations within the casing 3. That is, if the moisture concentration within the casing 3 is kept low by filling it with an inert gas, the reaction between the sulfide-based solid electrolyte contained in the battery cells 2 and moisture is suppressed, thereby reducing the amount of hydrogen sulfide generated. Even if hydrogen sulfide is generated from the battery cells 2, the coexistence of hydrogen sulfide and moisture can reduce the risk of accelerated corrosion of the materials of the battery cells 2 and their accessory components. Furthermore, if the oxygen concentration within the casing 3 is kept low by filling it with an inert gas, the possibility of hydrogen sulfide reacting with oxygen and resulting in combustion can be minimized.

[0031] 1, for convenience, the battery cells 2 and the ventilation section 5 are shown separated, but in reality, the battery cells 2 are placed on the ventilation section 5. In this case, the weight of the battery cells 2 may damage the hydrogen sulfide removal section 4, reducing its performance, or the battery cells 2 may not be sufficiently fixed, resulting in breakage of the electrode terminals or electrical circuits. Therefore, it is preferable that the ventilation section 5 have sufficient mechanical strength so that it can function as a support section that supports the battery cells 2 from below.

[0032] Second Embodiment Fig. 2 is a schematic diagram of a battery module according to a second embodiment of the present invention. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals in the drawing and their description will be omitted, and only the components different from those in the first embodiment will be described.

[0033] This embodiment is a modification of the first embodiment and differs from the first embodiment in that the configuration of the ventilation section 5 has been changed. Specifically, the ventilation section 5 is formed in a box or bag shape that surrounds and houses the hydrogen sulfide removal section 4. This allows the hydrogen sulfide removal section 4 and the ventilation section 5 to be handled as a single unit, facilitating installation of the hydrogen sulfide removal section 4 in the housing 3 during manufacture of the battery module 1 (or battery containing body) and facilitating replacement of the hydrogen sulfide removal section 4 after use. The other configurations of this embodiment are the same as those of the first embodiment, and the resulting effects, such as the ventilation section 5 functioning as a support for the battery cells 2, are also the same as those of the first embodiment.

[0034] 3 is a schematic diagram of a battery module according to a third embodiment of the present invention. Hereinafter, the same components as those in the above-described embodiments will be denoted by the same reference numerals in the drawings, and their description will be omitted. Only the components different from those in the above-described embodiments will be described.

[0035] This embodiment is a modification of the second embodiment and differs from the second embodiment in that multiple hydrogen sulfide removal units 4 and multiple ventilation units 5 are provided. This allows the size of each hydrogen sulfide removal unit 4 to be smaller than in the second embodiment, making it easier to manufacture the hydrogen sulfide removal units 4 when attempting to increase the size of the battery module 1 or to complicate the structure of the housing 3. Furthermore, compared to the second embodiment, which requires handling a single large hydrogen sulfide removal unit 4, installation and replacement of the hydrogen sulfide removal unit 4 are also easier. Furthermore, the provision of multiple ventilation units 5 allows the weight of the battery cells 2 to be shared among the multiple ventilation units 5, which is advantageous in that it increases the flexibility in selecting materials for the ventilation units 5 and ultimately increases the flexibility in design.

[0036] 4 is a schematic diagram of a battery module according to a fourth embodiment of the present invention. Hereinafter, the same components as those in the above-described embodiments will be denoted by the same reference numerals in the drawings, and their description will be omitted. Only the components different from those in the above-described embodiments will be described.

[0037] This embodiment is a modification of the second embodiment and differs from the second embodiment in that a support section 6 is newly provided. The support section 6 is located between the battery cell 2 storage space S and the hydrogen sulfide removal section 4, i.e., above the hydrogen sulfide removal section 4, and functions to support the battery cells 2 from below. The support section 6 is not particularly limited as long as it has a structure with sufficient mechanical strength and high breathability to support the battery cells 2. For example, a synthetic resin or metal plate-shaped member with multiple holes of any geometric shape, such as circular, elliptical, rectangular, or polygonal, can be used. The support section 6 may be formed integrally with the housing 3, or may be formed separately from the housing 3 and fixed to the housing 3. In either case, the weight of the battery cells 2 is not applied to the ventilation section 5, thereby increasing the flexibility in material selection for the ventilation section 5 and increasing the flexibility in design.

[0038] It goes without saying that the support portion 6 of this embodiment can also be applied to the third embodiment.

[0039] 5 is a schematic diagram of a battery module according to a fifth embodiment of the present invention. Hereinafter, the same components as those in the above-described embodiments will be denoted by the same reference numerals in the drawings, and their description will be omitted. Only components different from those in the above-described embodiments will be described.

[0040] This embodiment is a modification of the third embodiment and differs from the third embodiment in that multiple support sections 7 are newly provided. The multiple support sections 7 are arranged between the multiple hydrogen sulfide removal sections 4 and function to support the multiple battery cells 2 from below. The support sections 7 are not particularly limited as long as they have sufficient mechanical strength to support the battery cells 2. For example, a synthetic resin or metal member having a top plate 7a on which the battery cells 2 are placed and legs 7b supporting the top plate 7a can be used. The number of legs 7b per top plate 7a is not particularly limited and may be one or more. The support sections 7 may be formed integrally with the housing 3 or may be formed separately from the housing 3 and fixed to the housing 3. In either case, the weight of the battery cells 2 is not applied to the ventilation section 5, which allows for greater freedom in material selection for the ventilation section 5 and greater design freedom compared to the third embodiment. It is preferable that the support section 7 has high breathability, and therefore, it is preferable that a plurality of holes having any geometric shape, such as circular, elliptical, rectangular, or polygonal, be formed in the support section 7 to the extent that the mechanical strength is not reduced. In the example shown, the same number of support sections 7 as the number of battery cells 2 are provided, but the number of support sections 7 does not necessarily have to be the same as the number of battery cells 2, and may be changed to an appropriate number depending on various conditions.

[0041] This embodiment has the following advantage over the fourth embodiment, which has only one support part 6. Specifically, the size of each support part 7 can be reduced, which makes it easier to manufacture the support parts 7 even when attempting to increase the size of the battery module 1 or to complicate the structure of the housing 3. Furthermore, the provision of multiple support parts 7 means that the load of the battery cells 2 is shared among the multiple support parts 7, which increases the degree of freedom in selecting materials for the support parts 7 and therefore increases the degree of freedom in design.

[0042] In the above-described embodiment, the battery containing body of the present invention is exemplified as a battery module containing battery cells, but the present invention is not limited to this. For example, a battery pack may be formed by containing a battery module (i.e., modularized battery cells) in the battery containing body of the present invention, or a battery pack may be formed by containing non-modularized battery cells. In this sense, the battery modules exemplified in this specification can also be said to be moduleless battery packs. Note that the battery module contained in the battery containing body of the present invention is not limited to a battery module simply containing battery cells in a housing, but may also be a battery module containing battery cells in the battery containing body of the present invention. In this case, the provision of a dual hydrogen sulfide removal section (active gas removal section) further enhances the safety of the battery pack.

[0043] REFERENCE SIGNS LIST 1 Battery module 2 Battery cell 3 Housing 4 Hydrogen sulfide removal section (active gas removal section) 5 Ventilation section 6, 7 Support section S Storage space

Claims

1. A battery container having: a housing that houses battery cells; at least one active gas removal section that is disposed within the housing and removes active gas generated from the battery cells; and at least one ventilation section that is air-permeable and is provided at least in an area where the at least one active gas removal section faces the battery cells.

2. The battery housing according to claim 1, wherein the at least one active gas removal section is disposed below the space in which the battery cell is housed.

3. The battery housing according to claim 2, wherein the at least one ventilation section is a plate-shaped member disposed between the space and the at least one active gas removal section.

4. The battery housing according to claim 2, wherein the at least one ventilation section is a box-shaped or bag-shaped member that houses the at least one active gas removal section.

5. The battery containing body according to claim 3 or 4, wherein the at least one ventilation section functions as a support section that supports the battery cell from below.

6. The battery container according to claim 4, further comprising a support portion disposed above the at least one active gas removal portion and supporting the battery cell from below.

7. The battery containing body according to claim 4, wherein the at least one active gas removal section includes a plurality of active gas removal sections, and the at least one ventilation section includes a plurality of ventilation sections.

8. The battery containing body according to claim 7, further comprising a support portion disposed above the plurality of active gas removal portions and supporting the battery cell from below.

9. The battery container according to claim 7, further comprising a plurality of support sections arranged between the plurality of active gas removal sections and supporting the battery cells from below.

10. A battery module comprising: a battery housing according to any one of claims 1 to 4; and a battery cell housed in the housing of the battery housing.

11. A battery pack comprising the battery module according to claim 10.

12. A battery container comprising: a housing for housing a battery module; at least one active gas removal section disposed within the housing for removing active gas generated from the battery module; and at least one ventilation section having breathability, provided at least in an area where the at least one active gas removal section faces the battery module.

13. A battery pack comprising: the battery containing body according to claim 12; and a battery module contained in the housing of the battery containing body.

14. The battery pack according to claim 13, wherein the battery module is the battery module according to claim 10.

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