Battery module

Abstract

The problem to be solved by the present invention is to provide a battery module which uses a buffer material that can apply uniform pressure to a battery cell, has high heat insulation properties, and is easy to miniaturize. In order to solve the problem, provided is a battery module provided with: a battery cell laminate in which a plurality of battery cells are laminated; a pair of end plates provided at both ends of the battery cell laminate in the lamination direction; and a buffer material disposed between the battery cells and at least one of the battery cells, and between the battery cell laminate and the end plate. Furthermore, the cushioning material has a first bag and a second bag having a larger inner diameter than the first bag, and contains: a gas filled in the internal space of the first bag; and a liquid filled in a space between the first bag and the second bag.

Description

Technical Field

[0001] The present invention relates to a battery module. Background Art

[0002] In recent years, research and development of battery modules, which contribute to improved energy efficiency, has been underway to ensure more people have access to affordable, reliable, sustainable, and advanced energy. A battery module is a modular combination of multiple battery cells, typically consisting of a stack of stacked battery cells and a pair of end plates positioned at either end of the stack. Battery modules are used in applications requiring high current and high voltage, such as driving motors in electric and hybrid electric vehicles.

[0003] In battery modules, the placement of cushioning materials between battery cells or between a battery cell stack and end plates to apply pressure in the stacking direction of the battery cells is being explored. Known cushioning materials include those with a deformable cavity and a system for supplying a fluid to deform the cavity (Patent Document 1), and spring elastic bodies such as leaf springs and liquid springs (Patent Documents 2 and 3).

[0004] [Prior Art Literature]

[0005] (Patent Document)

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-64848

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2021-96974

[0008] Patent Document 3: European Patent Application Publication No. 3886202 Summary of the Invention

[0009] [Problems to be solved by the invention]

[0010] Incidentally, in the technology related to battery modules, improving the electric capacity has become a topic. In order to increase the electric capacity of the battery module, it is effective to apply uniform pressure to each battery cell assembled in the battery module via a buffer material. In addition, if a material with heat dissipation properties that release heat from the battery cell stack to the outside and heat insulation properties that suppress heat transfer between battery cells is used as the buffer material, it can have heat insulation properties in the cell stacking direction of the battery cell stack and heat conductivity in the direction perpendicular to the cell stacking direction, making it easier to control the temperature of the battery cell. However, if the thickness of the battery cell locally changes due to charging and discharging, the pressure applied to the buffer material from the battery cell locally increases or decreases, and it is sometimes difficult to apply uniform pressure from the buffer material to the battery cell. In addition, in order to increase the electric capacity per unit volume of the battery module, it is desired that the buffer material be small. However, if the buffer material is miniaturized, it is difficult to achieve both heat dissipation and heat insulation properties, and it may be difficult to obtain the above-mentioned effect.

[0011] The present invention has been developed in view of the above-mentioned circumstances, and its object is to provide a battery module using a buffer material that can apply uniform pressure to battery cells, has high thermal insulation properties, is easy to miniaturize, and further contributes to improving energy efficiency.

[0012] [Technical means to solve the problem]

[0013] The inventors discovered that the aforementioned issues can be resolved by using the following structure as a cushioning material, leading to the present invention. The structure comprises a double-pack structure comprising a first pack and a second pack with a larger inner diameter than the first pack, both ends of which are sealed; a gas is filled within the first pack; and a liquid is filled between the first and second packs. Therefore, the present invention provides the following solution.

[0014] (1) A battery module comprising: a battery cell stack having a plurality of battery cells stacked thereon; a pair of end plates provided at both ends of the battery cell stack in a stacking direction; and a buffer material disposed between the battery cells and at least one of the battery cells and between the battery cell stack and the end plates; and the buffer material having a first pack and a second pack having an inner diameter larger than that of the first pack, and containing: a gas filled in an inner space of the first pack; and a liquid filled in a space between the first pack and the second pack.

[0015] In the battery module of (1), for example, even if the pressure applied to the buffer material from the battery cell locally increases or decreases, the internal pressure of the buffer material becomes uniform due to the liquid filling the space between the first and second packs, thereby making the pressure applied to the battery cell from the buffer material uniform. In addition, since the interior of the first pack is filled with gas, the thermal insulation properties of the buffer material are improved. Moreover, the buffer material is composed of a double pack structure having the first and second packs, which has a relatively simple structure and is easy to miniaturize.

[0016] (2) In the battery module according to (1), the first pack and the second pack are separated from each other.

[0017] In the battery module of (2), since the heat conductivity between the first pack and the second pack is reduced, the heat insulation performance of the buffer material is improved.

[0018] (3) In the battery module according to (1) or (2), the cushioning material includes a vent pipe connected to the internal space of the first pack.

[0019] In the battery module of (3), the internal pressure of the buffer material can be adjusted by introducing gas into the internal space of the first pack through the vent pipe or exhausting the gas to the outside. Therefore, the pressure applied by the buffer material to the battery cells can be kept constant.

[0020] (4) In the battery module according to any one of (1) to (3), the buffer material includes a liquid supply pipe and a liquid discharge pipe connected to the space between the first pack and the second pack.

[0021] In the battery module (4), the internal pressure of the buffer material can be adjusted by introducing liquid into the space between the first and second packs via the liquid supply pipe or releasing the liquid via the liquid discharge pipe. Therefore, the pressure applied by the buffer material to the battery cells can be made more constant. Furthermore, the temperature of the buffer material can be adjusted by allowing the temperature-adjusted liquid to flow continuously through the space between the first and second packs via the liquid supply pipe and the liquid discharge pipe. Consequently, the thermal insulation properties of the buffer material are further improved.

[0022] (Effects of the Invention)

[0023] According to the present invention, a battery module can be provided that uses a buffer material that can apply uniform pressure to battery cells, has high heat insulation properties, and can be easily miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional view of a battery module according to the first embodiment of the present invention.

[0025] Figure 2 yes Figure 1Cross-sectional view along line II-II.

[0026] Figure 3 This is a cross-sectional view of a battery cell that can be used in the battery module according to the first embodiment of the present invention.

[0027] Figure 4 FIG. 1 is a cross-sectional view showing a battery module according to a second embodiment of the present invention.

[0028] Figure 5 This is a plan view of a buffer material used in a battery module according to a second embodiment of the present invention.

[0029] Figure 6 This is a first modified example of the buffer material used in the battery module of the present invention.

[0030] Figure 7 This is a second modified example of the buffer material used in the battery module of the present invention.

[0031] Figure 8 This is a third modified example of the buffer material used in the battery module of the present invention.

[0032] Figure 9 This is a fourth modified example of the buffer material used in the battery module of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments.

[0034] Figure 1 It is a cross-sectional view of a battery module according to the first embodiment of the present invention. Figure 2 yes Figure 1 Cross-sectional view along line II-II. Figure 3 This is a cross-sectional view of a battery cell that can be used in the battery module according to the first embodiment of the present invention.

[0035] like Figure 1 and Figure 2 As shown, the battery module 1 includes: a battery cell stack 100, which is stacked with a plurality of battery cells 10; a pair of end plates 20, which are provided in the stacking direction ( Figure 1 The module housing 40 includes a positive terminal 51 and a negative terminal 52. The positive terminal 51 and the negative terminal 52 are arranged in one direction (in the Z direction); and a buffer material 30, which is arranged between the battery cells 10 and the battery cells 10 and between the battery cell stack 100 and the end plate 20. The battery cell stack 100, the end plate 20 and the buffer material 30 are housed in the module housing 40. The module housing 40 has a positive terminal 51 and a negative terminal 52. The positive terminal 51 and the negative terminal 52 are arranged in one direction (in the Z direction); and a buffer material 30, which is arranged between the battery cells 10 and the battery cell stack 10 and between the end plate 20. Figure 1The positive electrode terminal 51 is connected to the positive electrode lead 11a of the battery cell 10. The negative electrode terminal 52 is connected to the negative electrode lead 14a of the battery cell 10.

[0036] The battery cell 10 is a battery that uses lithium ions as a charge transfer medium. Figure 3 As shown, the battery cell 10 includes an electrode stack 18 formed by stacking a positive electrode layer 11 and a negative electrode layer 14 via a solid electrolyte layer 17, and an outer casing 19 that houses the electrode stack 18. The positive electrode layer 11 includes a positive electrode current collector 12 and a positive electrode active material layer 13. The negative electrode layer 14 includes a negative electrode current collector 15 and a metal layer 16. When the battery cell 10 is charged, lithium ions released from the positive electrode active material layer 13 pass through the solid electrolyte layer 17 and precipitate on the surface of the metal layer 16 of the negative electrode layer 14, forming a lithium precipitation layer, which increases the thickness of the negative electrode layer 14. The lithium precipitation layer functions as a negative electrode active material layer and disappears when lithium ions are released during discharge. Therefore, the volume of the battery cell 10 changes due to charging and discharging. Therefore, the pressure applied by the battery cell 10 to the buffer material 30 changes due to charging and discharging. The stacking direction of the electrode stack 18 is the same as the stacking direction of the battery cell stack 100. That is, the plurality of battery cells 10 of the battery module 1 are stacked along the stacking direction of the electrode stack 18. Figure 4 In the illustrated battery cell 10 , a single electrode stack 18 is housed in the exterior body 19 . However, a plurality of electrode stacks 18 may be housed in the exterior body 19 .

[0037] The positive electrode current collector 12 is not particularly limited in material or shape as long as it has the function of collecting current from the positive electrode layer 11. Examples of materials for the positive electrode current collector 12 include aluminum, aluminum alloys, stainless steel, nickel, iron, and titanium, with aluminum, aluminum alloys, and stainless steel being preferred. Examples of the shape of the positive electrode current collector 12 include foil and plate.

[0038] The positive electrode active material layer 13 contains at least one positive electrode active material. There is no particular limitation on the positive electrode active material, and materials used in the positive electrode layer of a general solid secondary battery can be used. As the positive electrode active material, for example, a layered active material containing lithium, a spinel type active material, an olivine type active material, etc. can be used. Specific examples of positive electrode active materials include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), LiNiO2, etc. p Mn q Co r O2(p+q+r=1), LiNi p Al q Co r O2(p+q+r=1), lithium manganate (LiMn2O4), Li 1+x Mn2-x-y Heterogeneous element-substituted Li-Mn spinel represented by MO4 (x+y=2, M=at least one selected from Al, Mg, Co, Fe, Ni and Zn), lithium titanate (an oxide containing Li and Ti), lithium metal phosphate (LiMPO4, M=at least one selected from Fe, Mn, Co and Ni), etc.

[0039] From the perspective of improving lithium ion conductivity, the positive electrode active material layer 13 may optionally contain a solid electrolyte. Furthermore, to improve conductivity, a conductive additive may optionally be included. Furthermore, from the perspective of enhancing flexibility, a binder may optionally be included. The solid electrolyte, conductive additive, and binder are not particularly limited, and materials commonly used in the positive electrode layer of solid secondary batteries may be used.

[0040] The material of the positive electrode lead 11 a may be the same as or different from the material of the positive electrode current collector 12 . The positive electrode lead 11 a may be integrally connected to the positive electrode current collector 12 .

[0041] The negative electrode current collector 15 is not particularly limited in material or shape as long as it has the function of collecting current from the negative electrode layer 14. Examples of materials for the negative electrode current collector 15 include nickel, copper, and stainless steel. Examples of shapes for the negative electrode current collector 15 include foil and plate.

[0042] As long as the metal layer 16 has the function of densely precipitating lithium ions, there is no particular limitation on the material or shape. As the metal layer 16, a metallic lithium layer or a layer of a metal that forms an alloy with lithium can be used. Examples of metals that form alloys with lithium include Mg, Si, Au, Ag, In, Ge, Sn, Pb, Al, and Zn. The metal forming the metal layer 16 can be in powder form or in a thin film form. By using the negative electrode layer 14 having this metal layer 16, a uniform lithium precipitation layer can be generated on the surface of the metal layer 16.

[0043] The material of the negative electrode lead 14a may be the same as or different from the material of the negative electrode current collector 15. The negative electrode lead 14a may be integrally connected to the negative electrode current collector 15.

[0044] The solid electrolyte layer 17 contains at least one solid electrolyte. The solid electrolyte is not particularly limited as long as it has lithium ion conductivity, and for example, a sulfide solid electrolyte, an oxide solid electrolyte, a nitride solid electrolyte, a halide solid electrolyte, etc. can be used.

[0045] Examples of sulfide solid electrolytes include Li2S-P2S5, Li2S-P2S5-LiI, etc. The sulfide solid electrolyte may have an argyrodite-type crystal structure.

[0046] Examples of oxide solid electrolytes include NASICON type oxides, garnet type oxides, and perovskite type oxides. Examples of NASICON type oxides include oxides containing Li, Al, Ti, P, and O (e.g., Li 1.5 Al 0.5 Ti 1.5 (PO4)3). Examples of garnet-type oxides include oxides containing Li, La, Zr, and O (e.g., Li7La3Zr2O 12 Examples of perovskite-type oxides include oxides containing Li, La, Ti, and O (eg, LiLaTiO 3 ).

[0047] The outer casing 19 is capable of expanding and contracting in response to changes in the volume of the battery cell 10 caused by charge and discharge. A laminated film can be used as the material for the outer casing 19. A laminated film having a three-layer structure, in which an inner resin layer, a metal layer, and an outer resin layer are sequentially stacked from the inside, can be used. The outer resin layer can be, for example, a polyamide (nylon) layer or a polyethylene terephthalate (PET) layer, the metal layer can be, for example, an aluminum layer, and the inner resin layer can be, for example, a polyethylene layer or a polypropylene layer.

[0048] The end plate 20 constrains the battery cell stack 100 in the stacking direction. The constraining force of the end plate 20 adjusts the surface pressure applied by the buffer material 30 to the battery cell stack. The material of the end plate 20 is not particularly limited; various materials used for end plates in battery modules can be used.

[0049] The buffer material 30 has a function of making the surface pressure applied to the battery cell 10 uniform. The surface pressure applied to the battery cell 10 may be, for example, 1 MPa or more.

[0050] The cushioning material 30 includes a double pack structure 33 having a first pack 31 and a second pack 32 having a larger inner diameter than the first pack 31. The first pack 31 and the second pack 32 are separated from each other. A first space 35 inside the first pack 31 is filled with gas. A second space 36 between the first pack 31 and the second pack 32 is filled with liquid.

[0051] The area ratio of the first space 35 to the second space 36 in a cross-section perpendicular to the axial direction of the cushioning material 30 can also be set based on the thermal insulation and thermal conductivity of the cushioning material 30. From the perspective of thermal insulation, the ratio of the cross-sectional area of ​​the first space 35 to the total cross-sectional area of ​​the cushioning material 30 is preferably within a range of, for example, 20% to 50%. From the perspective of thermal conductivity, it is preferably within a range of, for example, 50% to 80% or less. For example, nitrogen can be used as the gas filling the first space. For example, mineral hydraulic oil, phosphate ester hydraulic oil, water, or a glycol solvent can be used as the liquid filling the second space 36.

[0052] The cushioning material 30 can be manufactured, for example, by accommodating a first tubular component containing gas in a second tubular component having an inner diameter larger than that of the first tubular component, injecting liquid between the first tubular component and the second tubular component, and then sealing the second tubular component. As the material of the first tubular component and the second tubular component, for example, a laminated film can be used.

[0053] The module case 40 houses the battery cell stack 100 and the end plate 20. The material of the module case 40 is not particularly limited; various materials used for battery module cases can be used. The material of the positive electrode terminal 51 can be the same as or different from the material of the positive electrode lead 11a. The material of the negative electrode terminal 52 can be the same as or different from the material of the negative electrode lead 14a.

[0054] In the battery module 1 of the present embodiment constructed as described above, even if the volume of the battery cells 10 increases due to charging, and the pressure applied by the battery cells 10 to the buffer material 30 increases locally, or even if the volume of the battery cells 10 decreases due to discharging, and the pressure applied by the battery cells 10 to the buffer material 30 decreases locally, the internal pressure of the buffer material 30 is made uniform by the liquid filling the second space 36 between the first pack 31 and the second pack 32. Therefore, the pressure applied by the buffer material 30 to the battery cells can be made uniform. In addition, since the first space 35 inside the first pack 31 is filled with gas, the thermal insulation performance of the buffer material 30 is improved. In addition, the buffer material 30 is composed of a double pack structure 33 having the first pack 31 and the second pack 32, which has a relatively simple structure and can be easily miniaturized. In addition, the first pack 31 and the second pack 32 are separated from each other, and the heat transfer between the first pack 31 and the second pack 32 is reduced, thereby improving the thermal insulation performance of the buffer material 30.

[0055] Figure 4 It is a cross-sectional view of a battery module according to a second embodiment of the present invention. Figure 5 This is a plan view of a buffer material used in a battery module according to a second embodiment.

[0056] like Figure 4 and Figure 5 As shown, the battery module 2 of the second embodiment includes a vent pipe 37 connected to the first space 35 of the buffer material 30, and includes a liquid supply pipe 38 and a liquid discharge pipe 39 connected to the second space 36. The structure otherwise is the same as that of the battery module 1 described above. Therefore, the same reference numerals are assigned to the components common to the battery module 1 described above, and their description will be omitted.

[0057] The vent tube 37 functions as an inlet and outlet for gas within the first space 35. For example, when the volume of the battery cell 10 increases during charging, the pressure exerted by the battery cell 10 on the buffer material 30 increases locally, and the internal pressure of the buffer material 30 rises. By discharging the gas within the first space 35 to the outside through the vent tube 37, the internal pressure of the buffer material 30 can be reduced. Furthermore, when the volume of the battery cell 10 decreases during discharge, and the pressure exerted by the battery cell 10 on the buffer material 30 decreases locally, the internal pressure of the buffer material 30 can be increased by introducing gas from the outside into the first space 35 through the vent tube 37. Furthermore, by introducing or exhausting gas from the first space 35 through the vent tube 37 during both charging and discharging, the pressure exerted by the buffer material 30 on the battery cell 10 can be adjusted.

[0058] The liquid supply tube 38 serves as an inlet for the liquid in the second space 36, and the liquid discharge tube 39 serves as an outlet for the liquid in the second space 36. For example, when the volume of the battery cell 10 decreases due to discharge and the pressure exerted on the buffer material 30 by the battery cell 10 decreases locally, the internal pressure of the buffer material 30 can be increased by introducing liquid from the outside into the second space 36 through the liquid supply tube 38. Furthermore, when the volume of the battery cell 10 increases due to charging and the pressure exerted on the buffer material 30 by the battery cell 10 increases locally, causing the internal pressure of the buffer material 30 to increase, the internal pressure of the buffer material 30 can be reduced by discharging the liquid in the second space 36 to the outside through the liquid discharge tube 39. Furthermore, by adjusting the internal pressure in the first space 35 via the buffer material 30, the pressure exerted on the battery cell 10 can also be adjusted during both charging and discharging. Furthermore, during both charging and discharging, the pressure exerted by the buffer material 30 on the battery cell 10 can be adjusted by introducing liquid into the second space 36 via the liquid supply pipe 38 or by releasing the liquid via the liquid discharge pipe 39. Furthermore, the internal temperature of the buffer material 30 can be adjusted by supplying liquid, whose temperature has been adjusted, into the second space 36 via the liquid supply pipe 38 and by releasing the liquid to the outside via the liquid discharge pipe 39.

[0059] Similar to the battery module 1, the battery module 2 of the second embodiment comprises a double-pack structure 33 comprising a first pack 31 and a second pack 32, a gas filling the first space 35, and a liquid filling the second space 36. Therefore, it exhibits the same effects as the battery module 1. Furthermore, the battery module 2 of the second embodiment adjusts the internal pressure of the buffer material 30 by introducing gas or exhausting the gas into the first space 35 via the vent pipe 37, thereby maintaining a constant pressure applied by the buffer material 30 to the battery cells 10. Furthermore, the battery module 2 of the second embodiment adjusts the internal pressure of the buffer material 30 by introducing liquid into the second space 36 via the liquid supply pipe 38 or discharging the liquid via the liquid discharge pipe 39, thereby maintaining a more constant pressure applied by the buffer material 30 to the battery cells 10. Furthermore, by continuously flowing the temperature-adjusted liquid into the second space 36 via the liquid supply pipe 38 and the liquid discharge pipe 39, the temperature of the buffer material 30 can be adjusted, further enhancing the thermal insulation properties of the buffer material 30.

[0060] In the battery modules 1 of the first embodiment and the battery modules 2 of the second embodiment, the cushioning material 30 is a double pack structure 33 having a first pack 31 inside a second pack 32. However, the structure of the cushioning material 30 is not limited thereto. For example, two or more first packs 31 may be inside the second pack 32. Figures 6 to 9 A modified example of the cushioning material 30 is shown.

[0061] Figure 6 It is a first variation of the buffer material used in the battery module of the present invention. The buffer material 30a of the first variation has two first packages 31a and 31b inside the second package 32. The first package 31a and the first package 31b are respectively configured to be arranged on the end side of the second package 32. The first space 35 of the first package 31a and 31b is filled with gas, and the second space 36 between the first package 31a and 31b and the second package 32 is filled with liquid. The first space 35 filled with gas has higher thermal insulation performance than the second space 36 filled with liquid. The second space 36 filled with liquid has higher cooling performance than the first space 35 filled with gas. Therefore, the buffer material 30a of the first variation has higher thermal insulation performance on the end side of the second package 32 and higher cooling performance in the center part of the second package 32 than the buffer material 30.

[0062] Figure 7 This is a second variation of the cushioning material used in the battery module of the present invention. The cushioning material 30b of the second variation is configured such that the first pack 31c is positioned between the first pack 31a and the first pack 31b of the first variation. Therefore, the cushioning material 30b of the second variation has higher uniformity in thermal insulation and cooling performance than the cushioning material 30a of the first variation.

[0063] Figure 8 This is a third modification of the cushioning material used in the battery module of the present invention. The cushioning material 30c of the third modification is configured such that the first packing 31c located in the center of the second packing 32 of the cushioning material 30b of the second modification is replaced with a flattened, oval-shaped first packing 31d, and the second space 36 is widened. Therefore, the cushioning material 30c of the third modification has improved cooling performance in the center of the second packing 32 compared to the cushioning material 30b of the second modification.

[0064] Figure 9 This is a fourth variation of the cushioning material used in the battery module of the present invention. The cushioning material 30d of the fourth variation is configured such that flat, circular first packings 31e and 31f are arranged parallel to the center of the second packing 32 in a direction perpendicular to the thickness of the second packing 32. Therefore, compared to the cushioning material 30, the cushioning material 30d of the fourth variation has higher cooling performance at the ends of the second packing 32 and higher thermal insulation performance at the center of the second packing 32.

[0065] As shown in the first packs 31 a to 31 f of the cushioning materials 30 a to 30 d , the balance between the cooling performance and the heat insulating performance of the cushioning materials can be adjusted by the shape or arrangement of the first packs.

[0066] Preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments and can be modified as appropriate.

[0067] For example, in the above embodiment, the first pack 31 and the second pack 32 of the cushioning material 30 are separated from each other, but the arrangement of the first pack 31 and the second pack 32 is not limited thereto. The first pack 31 and the second pack 32 may be partially in contact with each other.

[0068] In the above embodiment, the battery cell 10 is described as a solid battery having a solid electrolyte layer 17 , but the battery cell 10 is not limited thereto. The battery cell 10 may be, for example, a non-aqueous battery using an organic electrolyte solution as an electrolyte or a polymer battery using a high molecular gel (polymer).

[0069] In the above embodiment, the buffer materials 30 and 130 are disposed between the battery cells 10 and between the battery cells 10 and the end plates 20. However, the locations of the buffer materials 30 and 130 are not limited to this. The buffer materials 30 and 130 only need to be disposed at least one of the locations between the battery cells 10 and the end plates 20.

[0070] Reference numerals

[0071] 1, 2: Battery module

[0072] 10: Battery cells

[0073] 11: Positive electrode layer

[0074] 11a: Positive lead

[0075] 12: Positive electrode collector

[0076] 13: Positive electrode active material layer

[0077] 14: Negative electrode layer

[0078] 14a: Negative lead

[0079] 15: Negative electrode collector

[0080] 16: Metal layer

[0081] 17: Solid electrolyte layer

[0082] 18: Electrode stack

[0083] 19: Exterior body

[0084] 20: End plate

[0085] 30, 30a, 30b, 30c, 30d: Cushioning material

[0086] 31, 31a, 31b, 31c, 31d, 31e, 31f: First package

[0087] 32: Second pack

[0088] 33: Double package structure

[0089] 35: First Space

[0090] 36: Second Space

[0091] 37: Ventilation tube

[0092] 38: Liquid supply pipe

[0093] 39: Drain pipe

[0094] 40: Module housing

[0095] 51: Positive terminal

[0096] 52: Negative terminal

Claims

1. A battery module comprising: A battery cell stack having a plurality of battery cells stacked thereon; a pair of end plates provided at both ends of the battery cell stack in the stacking direction; and A buffer material is disposed between the battery cells and at least one of the battery cells and between the battery cell stack and the end plate; and The cushioning material comprises a first package and a second package having an inner diameter larger than that of the first package, and includes: The gas is filled in the inner space of the first bag; and the liquid is filled in the space between the first bag and the second bag.

2. The battery module according to claim 1, wherein: The first package and the second package are separated from each other.

3. The battery module according to claim 1 or 2, wherein: The cushioning material includes a vent pipe connected to the inner space of the first pack.

4. The battery module according to claim 1 or 2, wherein: The cushioning material includes a liquid supply tube and a liquid discharge tube connected to the space between the first pack and the second pack.

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