Battery module

Abstract

The invention relates to a battery module. The plurality of battery cells are arranged in a first direction. The spacers are located between the plurality of battery cells. The spacer includes an elastic body that is elastically deformable in at least a first direction. The elastomer has a first portion. The first portion has a frame shape that extends around an axis in the first direction and defines a sealed space on the inside. In the first direction, the thickness of the first portion in a non-loaded state is 1.30 times or more and 2.87 times or less with respect to the thickness of the first portion in a state of being disposed between the plurality of battery cells and elastically deformed in the compression direction.

Description

Technical Field

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

[0002] As a prior art document that discloses the structure of a buffer sheet for a battery module, there is Japanese Patent Publication No. 2020-4556. The buffer sheet for a battery module described in Japanese Patent Publication No. 2020-4556 has a plate-shaped base and an elastic protrusion. The elastic protrusion is formed to protrude from the base toward the target surface of the battery cell. The elastic protrusion elastically supports the battery cell when the battery cell expands in a curved shape due to charging, and applies a reaction force to the battery cell when the battery cell contracts due to discharging.

[0003] As a prior art document that discloses the structure of a holder for an electric storage element, there is Japanese Patent Publication No. 2010-238554. The holder described in Japanese Patent Publication No. 2010-238554 supports a plurality of electric storage elements. The holder includes an elastic body and an injection portion. The elastic body includes a hollow portion in a sealed state. The injection portion injects gas into the hollow portion. The electric storage element is pressurized in accordance with the increase in pressure in the hollow portion.

[0004] In the buffer sheet for battery module described in Japanese Patent Application Laid-Open No. 2020-4556, as the elastic protrusion is elastically deformed, the load for elastic deformation of the elastic protrusion increases. As a result, the elastic protrusion cannot be elastically deformed sufficiently, and the reaction force of the spacer to the expansion of the battery cell may be reduced.

[0005] In the holder for an electric storage element described in Japanese Patent Application Laid-Open No. 2010-238554, the pressure inside the hollow portion is adjusted by the injection portion, so the structure becomes complicated. Summary of the invention

[0006] The present technology has been made to solve the above-mentioned problems, and an object of the present technology is to provide a battery module capable of suppressing a decrease in the reaction force of a spacer to the expansion of a battery cell with a simple structure.

[0007] The present technology provides the following battery modules. [1]

[0009] A battery module comprising:

[0010] a plurality of battery cells arranged in a first direction; and

[0011] a spacer, the spacer being located between the plurality of battery cells,

[0012] The spacer includes an elastic body capable of elastic deformation at least in the first direction,

[0013] The elastic body has a first portion, the first portion having a frame shape extending around an axis in the first direction and defining a closed space inside.

[0014] In the first direction, a thickness of the first portion in an unloaded state is 1.30 to 2.87 times greater than a thickness of the first portion disposed between the plurality of battery cells and elastically deformed in a compression direction. [2]

[0016] The battery module according to [1],

[0017] The first portion abuts against at least one battery cell among the plurality of battery cells at a first abutting surface in the first direction,

[0018] The first abutting surface has a concavo-convex shape. [3]

[0020] The battery module according to [2],

[0021] The first portion abuts against one of two battery cells sandwiching the spacer among the plurality of battery cells at the first abutting surface.

[0022] The width of the first portion becomes narrower as it moves from the other of the two battery cells toward the one of the two battery cells in the first direction. [4]

[0024] The battery module according to any one of [1] to [3],

[0025] The elastic body further includes a connecting portion, which is located at an end of the first portion in the first direction and connects the peripheral edges of the frame shape of the first portion. [5]

[0027] The battery module according to any one of [1] to [4],

[0028] The elastic body further includes a second portion, the second portion being located outside the first portion when viewed from the first direction and having a frame shape extending around an axis in the first direction,

[0029] The second portion abuts against at least one battery cell among the plurality of battery cells at a second abutting surface in the first direction,

[0030] In the first direction, the thickness of the second portion in contact with the at least one battery cell is substantially the same as the thickness of the first portion disposed between the plurality of battery cells and elastically deformed in the compression direction. [6]

[0032] The battery module according to [5],

[0033] In a direction orthogonal to the first direction, a gap is provided between the first portion and the second portion. [7]

[0035] The battery module according to [1],

[0036] The elastic body further includes a second portion, the second portion being located outside the first portion when viewed from the first direction and having a frame shape extending around an axis in the first direction,

[0037] The first portion abuts against at least one battery cell among the plurality of battery cells at a first abutting surface in the first direction,

[0038] The second portion abuts against the at least one battery cell at a second abutting surface in the first direction,

[0039] The first portion has a first width of a portion of the frame shape in a direction perpendicular to the first direction at an end portion on the side opposite to the side where the first abutting surface is located in the first direction.

[0040] The second portion has a second width of a portion of the frame shape in a direction perpendicular to the first direction at an end portion on the side opposite to the side where the second abutting surface is located in the first direction.

[0041] The second width is wider than the first width. [8]

[0043] The battery module according to [1],

[0044] The elastic body further includes a second portion, the second portion being located outside the first portion when viewed from the first direction and having a frame shape extending around an axis in the first direction,

[0045] The first portion abuts against one of two battery cells sandwiching the spacer among the plurality of battery cells at a first abutting surface.

[0046] The first portion has a tapered surface that faces the second portion and inclines from an outer side to an inner side of an axis around the first direction as it moves from the other side to the one side of the plurality of battery cells in a no-load state. [9]

[0048] The battery module according to any one of [1] to [8],

[0049] The spacer also includes a heat insulating material which is disposed in the enclosed space and has an inner space.

[10]

[0051] The battery module according to any one of [1] to [9],

[0052] An adhesive layer is further provided for bonding the elastic body and the plurality of battery cells in the first direction.

[0053] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a perspective view showing the structure of a battery module according to Embodiment 1 of the present technology.

[0055] Figure 2 This is a perspective view showing the internal structure of the battery module according to the first embodiment of the present technology.

[0056] Figure 3 This is a perspective view showing the structure of a battery cell included in the battery module according to the first embodiment of the present technology.

[0057] Figure 4 Observe from the direction of the arrow on line IV-IV Figure 2 A cross-sectional view of a battery module.

[0058] Figure 5 Observe from the direction of the arrow on the VV line Figure 2 A cross-sectional view of a battery module.

[0059] Figure 6 This is a cross-sectional view showing a state in which no load is applied to the spacer included in the battery module according to the first embodiment of the present technology.

[0060] Figure 7 This is a cross-sectional view showing a state in which pressure from a sealed space of a spacer is applied to a battery cell when the battery cell included in the battery module according to the first embodiment of the present technology expands.

[0061] Figure 8 This is a cross-sectional view showing a load required to support the battery cells included in the battery module according to the first embodiment of the present technique using a spacer.

[0062] Fig. 9 This is a graph showing the relationship between the ratio of the thickness after compressive deformation to the thickness before compressive deformation of the separators in the battery modules of Embodiment 1 and Comparative Example and the load.

[0063] Fig.10 This is a cross-sectional view showing the structure of a battery module according to Embodiment 2 of the present technology.

[0064] Fig.11 This is a cross-sectional view showing the structure of a battery module according to Embodiment 3 of the present technique.

[0065] Fig.12 This is a cross-sectional view showing the structure of a battery module according to Embodiment 4 of the present technology.

[0066] Fig.13 This is a cross-sectional view showing the structure of a battery module according to Embodiment 5 of the present technique.

[0067] Fig.14 This is a cross-sectional view showing the structure of a battery module according to Embodiment 6 of the present technology.

[0068] Fig.15 This is a cross-sectional view showing the structure of a battery module according to Embodiment 7 of the present technology.

[0069] Fig.16 This is a cross-sectional view showing the structure of a battery module according to an eighth embodiment of the present technology.

[0070] Fig.17 This is a cross-sectional view showing the structure of a spacer in a battery module according to Embodiment 9 of the present technology when the spacer is in a no-load state.

[0071] Fig.18 Observe from the direction of the arrow on line XVIII-XVIII Fig.17 A cross-sectional view of a battery module.

[0072] Fig.19 This is a cross-sectional view showing a structure of a battery module according to Embodiment 9 of the present technology in a state where a spacer is compressed and deformed.

[0073] Fig. 20 This is a cross-sectional view showing the structure of a spacer in a battery module according to a tenth embodiment of the present technology when it is in a no-load state.

[0074] Fig.21 This is a cross-sectional view showing a structure of a battery module according to a tenth embodiment of the present technology in a state where a spacer is compressed and deformed. DETAILED DESCRIPTION

[0075] Hereinafter, embodiments of the present technology will be described. It should be noted that the same reference numerals may be given to the same or corresponding parts, and description thereof may not be repeated.

[0076] It should be noted that, in the embodiments described below, when the number, amount, etc. are mentioned, except for the cases specifically described, the scope of the present technology is not necessarily limited to the number, amount, etc. In addition, in the following embodiments, except for the cases specifically described, each component is not necessarily essential to the present technology. In addition, the present technology is not necessarily limited to achieving all the effects mentioned in the present embodiment.

[0077] It should be noted that in this specification, the descriptions of “comprise”, “include”, and “have” are open-ended. That is, when a certain structure is included, other structures other than the structure may or may not be included.

[0078] In addition, in this specification, when geometrical terms and terms indicating position / direction relationships, such as "parallel", "orthogonal", "inclined at 45°", "coaxial", "along", etc., are used, these terms allow for manufacturing errors or slight variations. In this specification, when terms such as "upper side" and "lower side" are used to indicate relative positional relationships, these terms are used as terms indicating relative positional relationships in one state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, turning the entire mechanism upside down, etc.).

[0079] In this specification, "battery" is not limited to lithium-ion batteries, and may include other batteries such as nickel-hydrogen batteries and sodium-ion batteries. In this specification, "electrode" may be collectively referred to as positive electrode and negative electrode.

[0080] In addition, the "battery module" can be installed in a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (BEV), etc. However, the use of the "battery module" is not limited to vehicle use.

[0081] It should be noted that in the drawings, the direction in which the positive terminal and the negative terminal of the battery cell are arranged is set to the X direction as the second direction, the direction in which the plurality of battery cells are arranged is set to the Y direction as the first direction, and the direction in which the upper surface and the lower surface of the battery cell are arranged is set to the Z direction as the third direction. In addition, in order to facilitate understanding of the present technology, there are portions in which the dimensions of the various structures in the drawings are changed from the actual dimensions. (Implementation method 1)

[0082] First, the structure of the battery module according to the first embodiment of the present technology will be described. Figure 1This is a perspective view showing the structure of a battery module according to Embodiment 1 of the present technology. Figure 2 This is a perspective view showing the internal structure of the battery module according to the first embodiment of the present technology.

[0083] like Figure 1 and Figure 2 As shown, the battery module 1 according to the first embodiment of the present technology includes a battery cell 100 , an end plate 200 , a restraint member 300 , and a spacer 400 .

[0084] The plurality of battery cells 100 are arranged in the first direction (Y direction). A spacer 400 described below is disposed between the battery cells 100. The plurality of battery cells 100 sandwiched between the two end plates 200 are pressed by the end plates 200 via the spacer 400 and are constrained between the two end plates 200.

[0085] The end plates 200 are provided at both ends of the plurality of battery cells 100 in the first direction (Y direction). The end plates 200 are fixed to a base such as a frame that accommodates the battery module 1. The end plates 200 are made of, for example, aluminum or iron.

[0086] like Figure 1 As shown, the restraining member 300 is provided at both ends of the plurality of battery cells 100 and the end plate 200 in the X direction. When the compressive force in the Y direction is applied to the stacked plurality of battery cells 100 and the end plate 200, the restraining member 300 is engaged with the end plate 200, and then the compressive force is released, thereby applying a tensile force to the restraining member 300 connecting the two end plates 200. As a reaction, the restraining member 300 presses the two end plates 200 in a direction close to each other. As a result, the restraining member 300 restrains the plurality of battery cells 100 in the Y direction.

[0087] The spacer 400 is disposed between the plurality of battery cells 100. In addition, the spacer 400 is disposed between the battery cells 100 located at the ends in the Y direction among the plurality of battery cells 100 and the end plate 200. The spacer 400 abuts against the long side surfaces of the plurality of battery cells 100 or the long side surfaces of the end plate 200.

[0088] The spacer 400 has insulating properties. Thus, the spacer 400 insulates the plurality of battery cells 100 from each other or from the battery cells 100 and the end plates 200. The spacer 400 will be described in detail later.

[0089] Figure 3 This is a perspective view showing the structure of a battery cell included in the battery module according to the first embodiment of the present technology.

[0090] like Figure 3 As shown, the battery cell 100 includes an electrode terminal 110 , a case 120 , a gas exhaust valve 130 , and an electrode body 140 .

[0091] The electrode terminal 110 is formed on the case 120. The electrode terminal 110 includes a positive electrode terminal 111 and a negative electrode terminal 112. The positive electrode terminal 111 and the negative electrode terminal 112 are arranged side by side in the second direction (X direction).

[0092] The case 120 is a container for accommodating the electrode body 140 and the electrolyte. The case 120 has a substantially rectangular parallelepiped shape. The case 120 is made of aluminum, aluminum alloy, iron, iron alloy, or the like.

[0093] The housing 120 has an upper surface 121 , a lower surface 122 , a pair of long side surfaces 123 , and a pair of short side surfaces 124 .

[0094] The electrode terminal 110 is arranged on the upper surface 121. The lower surface 122 faces the upper surface 121 in the third direction (Z direction).

[0095] A pair of long side surfaces 123 and a pair of short side surfaces 124 constitute the side surfaces of the housing 120. The pair of long side surfaces 123 and the pair of short side surfaces 124 as the side surfaces of the housing 120 intersect with the upper surface 121 and the lower surface 122, respectively. The pair of long side surfaces 123 face each other by sandwiching the electrode body 140 in the first direction (Y direction). The pair of short side surfaces 124 face each other by sandwiching the electrode body 140 in the second direction (X direction). The pair of long side surfaces 123 each have an area larger than the area of ​​each of the pair of short side surfaces 124.

[0096] The gas discharge valve 130 breaks when the pressure in the housing 120 reaches a predetermined value or more. As a result, the gas in the housing 120 is discharged to the outside of the housing 120 .

[0097] The electrode body 140 functions as a power generation element. The electrode body 140 includes a positive electrode and a negative electrode (not shown). The substrate constituting the positive electrode is, for example, an aluminum alloy foil. The substrate constituting the negative electrode is, for example, a copper alloy foil. The electrode body 140 is, for example, a wound electrode body in which a positive electrode and a negative electrode are wound, or a stacked electrode body in which a positive electrode and a negative electrode are alternately stacked.

[0098] Figure 4 Observe from the direction of the arrow on line IV-IV Figure 2 A cross-sectional view of a battery module. Figure 5 Observe from the direction of the arrow on the VV line Figure 2 A cross-sectional view of a battery module.

[0099] like Figure 4 and Figure 5 As shown, the spacer 400 in this embodiment includes an elastic body 410. In addition, the battery module 1 in this embodiment further includes an adhesive layer 500.

[0100] The elastic body 410 is elastically deformable at least in the first direction (Y direction) and in all directions including the first direction (Y direction), the second direction (X direction) and the third direction (Z direction).

[0101] The elastic body 410 may be made of an electrically insulating and elastic material such as silicone rubber, fluororubber, polyurethane rubber, natural rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber (EPM or EPDM), butadiene rubber, isoprene rubber, or norbornene rubber.

[0102] The elastic body 410 has a frame-shaped first portion 411 extending around an axis in a first direction (Y direction). In addition, the first portion 411 in this embodiment is composed of one member, but is not limited to this structure. The first portion 411 may also be composed of two or more members. In the case where the first portion 411 is composed of two or more members, the members are bonded to each other by bonding or the like.

[0103] The first portion 411 contacts at least one of the plurality of battery cells 100 at the first contact surface 412 in the first direction (Y direction). In the present embodiment, the first portion 411 contacts at the first contact surface 412 one of the two battery cells 100 sandwiching the spacer 400.

[0104] The adhesive layer 500 bonds the elastic body 410 to the plurality of battery cells 100 in the first direction (Y direction). In the present embodiment, the adhesive layer 500 bonds the first portion 411 to the other of the two battery cells 100b sandwiching the spacer 400 at the end portion of the first portion 411 on the side opposite to the side where the first abutting surface 412 is located in the first direction (Y direction). In addition, the adhesive layer 500 does not necessarily need to be provided in the battery module 1.

[0105] The first portion 411 is sandwiched between the plurality of battery cells 100 in the first direction (Y direction) and elastically deforms in the compression direction. The first portion 411 elastically deformed in the compression direction has a thickness T.

[0106] The thickness T of the first portion 411 can be calculated, for example, by subtracting the thickness of the end plate 200 and the thickness of each of the plurality of battery cells 100 from the entire length of the battery module 1 in the first direction (Y direction) and dividing the result by the number of spacers 400 .

[0107] The first portion 411 defines the enclosed space 10 inside. “Defining the enclosed space 10” includes the case where the enclosed space 10 is formed by the elastic body 410 alone and the case where the enclosed space 10 is formed by the elastic body 410 and other members. The other members may be the battery cell 100 or other elastic members.

[0108] The sealed space 10 in the present embodiment is formed by being surrounded by two battery cells 100 among the plurality of battery cells 100 in the first direction (Y direction) and by being surrounded by the first portion 411 around the axis in the first direction (Y direction).

[0109] Figure 6 This is a cross-sectional view showing a state in which no load is applied to the spacer included in the battery module according to the first embodiment of the present technology.

[0110] like Figure 6 As shown, before assembling the components of the battery module 1, the spacer 400 is in an unloaded state without being pressed by the battery cell 100. The first portion 411 of the spacer 400 in the unloaded state has a thickness T0 in the first direction (Y direction).

[0111] The first portion 411 is sandwiched between the battery cells 100 and pressed from a no-load state, whereby the first portion 411 is elastically deformed in the compression direction. Figure 5 and Figure 6 As shown, the first portion 411 is elastically deformed so that the thickness T0 of the first portion 411 becomes the thickness T.

[0112] When the first portion 411 is elastically deformed so that the thickness T0 of the first portion 411 becomes the thickness T, the sealed space 11 of the first portion 411 in the unloaded state is compressed. As a result, the compressed sealed space 10 has a higher pressure than the sealed space 11 in the unloaded state. The pressure P of the sealed space 10 is applied to the battery cell 100.

[0113] Figure 7 This is a cross-sectional view showing a state in which pressure from a sealed space of a spacer is applied to a battery cell when the battery cell included in the battery module according to the first embodiment of the present technology expands.

[0114] like Figure 7 As shown, the battery cell 100 may expand due to charging of the battery module 1, etc. In this case, the pressure P in the sealed space 10 of the first portion 411 becomes a reaction force to the expansion of the battery cell 100. Therefore, it is required to set an appropriate pressure P to the expansion of the battery cell 100.

[0115] The pressure P of the enclosed space 10 can be adjusted according to the degree of volume change of the enclosed space 10 before and after the compression deformation. In this embodiment, the pressure P of the enclosed space 10 is set by adjusting the ratio (T0 / T) of the thickness of the first portion 411 before and after the compression deformation related to the volume change of the enclosed space 10.

[0116] Figure 8 This is a cross-sectional view showing a load required to support the battery cells included in the battery module according to the first embodiment of the present technique using a spacer.

[0117] If no load is applied to constrain the battery cell 100, when the battery cell 100 vibrates, the position of the electrode body 140 may be shifted inside the housing 120, and the electrode body 140 may be damaged. Figure 8 As shown, it is necessary to apply a load F to constrain the battery cell 100 to prevent the electrode from shifting due to friction between the case 120 and the electrode body 140 during vibration. The ratio (T0 / T) of the thickness of the first portion 411 before and after the compression deformation is defined as the pressure P for applying the load F.

[0118] The ratio (T0 / T) of the thickness of the first portion 411 before and after the compressive deformation can be calculated using the load F according to Boyle's law by T0 / T=(load F+atmospheric pressure) / atmospheric pressure (Formula 1).

[0119] In addition, when calculating the load F, the temperature change is added to the calculation formula of the load F as a parameter of the environmental change after the battery cell 100 is completed. Specifically, the ambient temperature of the no-load state during the assembly of the battery cell 100 is assumed to be 25°C, and the ambient temperature after the battery cell 100 is completed is assumed to be -30°C. In this way, the load F can be calculated by load F = density of the electrode body × thickness of the battery cell × gravitational acceleration × acceleration of vibration / friction coefficient between the electrode body and the shell / number of contact surfaces between the electrode body and the shell × ((273+25°C) / (273-30°C))... (Formula 2).

[0120] Table 1 shows various conditions such as the density of the electrode body assumed in order to define the ratio of the thickness of the elastic body before and after the compression deformation.

[0121] [Table 1]

[0122] The conditions of the battery cell 100 are shown in Table 1. The load F varies depending on the specifications of the battery cell. As shown in Table 1, in this embodiment, the density of the electrode body 140 is 2.1 g / cm 3 Above and 2.6g / cm 3the following.

[0123] In addition, the vibration acceleration is assumed to be 12 G. Regarding the vibration acceleration, in the vibration characteristic evaluation of the United Nations Recommendations on Transport (UN test) for lithium-ion batteries, the maximum vibration acceleration is set to 12 G with a safety factor of 1.5 from 8 G. In addition, the friction coefficient between the electrode body and the shell is assumed to be 0.05.

[0124] By substituting the density of the electrode body 140 and the like into the above-mentioned Formula 2, the load F can be calculated to be 0.030 MPa or more and 0.187 MPa or less.

[0125] Substituting the calculated load F into the above formula 1, T0 / T is calculated to be 1.30 times or more and 2.87 times or less. That is, in the first direction (Y direction), the thickness T0 of the first portion 411 in the unloaded state is 1.30 times or more and 2.87 times or less relative to the thickness T of the first portion 411 in the state of being arranged between the plurality of battery cells 100 and elastically deformed in the compression direction. Thus, the appropriate pressure P of the enclosed space 10 is set.

[0126] Fig. 9 This is a graph showing the relationship between the ratio of the thickness after compressive deformation to the thickness before compressive deformation of the separators in the battery modules of Embodiment 1 and Comparative Example and the load.

[0127] The battery module of the comparative example is different from the battery module of the present embodiment in that the structure of the spacer is a solid elastic body without a closed space. Fig. 9 As shown, when the elastomer is solid, as the compression deformation increases, the load for changing the thickness increases, and the elastomer of the comparative example is difficult to deform elastically. Therefore, the expansion generated during the use of the battery cell is not easily absorbed by the spacer. Therefore, the reaction force of the battery cell applied to the end plate and the restraining member becomes larger. Therefore, it is necessary to make the end plate and the restraining member firm, resulting in the problem of increased mass of the battery module.

[0128] On the other hand, in this embodiment, air is compressed in the sealed space 11 inside the elastic body 410. Compared with the spacer of the comparative example, air can be compressed and deformed more easily than the elastic body, so the load for compression and deformation is small. As described in detail later, the weight of the battery module can be reduced.

[0129] As a method for manufacturing the battery module 1 of the present embodiment, first, the spacer 400 is prepared. The spacer 400 is formed by, for example, injection molding or the like.

[0130] Next, a plurality of battery cells 100 are arranged in a first direction (Y direction). Next, an adhesive layer 500 is applied to one side of the spacer 400. Next, the spacer 400 is arranged between the plurality of battery cells 100. Next, the spacer 400 is bonded to one of the two battery cells 100 sandwiching the spacer 400 using the adhesive layer 500. Then, the spacer 400 is pressed from the first direction (Y direction) together with the end plate to elastically deform the first portion 411. Thus, the spacer 400 is compressed and deformed in the first direction (Y direction), and the battery module 1 having the enclosed space 10 with the pressure P is completed.

[0131] In the battery module 1 of the first embodiment of the present technology, the spacer 400 is formed by an elastic body 410 including a first portion 411 having a frame shape, and the pressure P in the enclosed space 10 inside the first portion 411 is set to the reaction force of the expansion of the spacer 400 relative to the battery cell 100. The thickness T of the elastic body 410 after compression deformation in the stacking direction of the battery cell 100 is set to a ratio of 1.30 times or more and 2.87 times or less relative to the thickness T0 when there is no load. Thus, it is possible to ensure that the required pressure P is maintained without the electrode body being deviated and damaged during vibration. In addition, compared with the case where the spacer is composed of a solid elastic body, the load increase is small even if it is compressed, so even if the battery cell expands during the use of the battery cell, the increase in the reaction force can be suppressed. As a result, the strength of the end plate and the restraining member can be reduced, so the weight of these members can be reduced. In addition, by defining the thickness T of the elastic body 410 after compression deformation according to the thickness T0 in the unloaded state, the pressure P required for the reaction force against the battery cell 100 can be obtained in the closed space 10 of the elastic body 410, so that the spacer 400 can be made into a simple structure compared with the case where the closed space is provided in the spacer and the internal pressure of the closed space is adjusted by a separate structure for adjusting the pressure. As a result, the reaction force of the spacer 400 against the expansion of the battery cell 100 can be suppressed by a simple structure.

[0132] In the battery module 1 according to the first embodiment of the present technique, the battery cell 100 and the elastic body 410 are bonded together by the adhesive layer 500 , so that the spacer 400 can be easily positioned with respect to the battery cell 100 . Therefore, the battery module 1 can be easily assembled.

[0133] The battery modules of embodiments 2 to 10 of the present technology are described below. The structure of the spacer of the battery modules of embodiments 2 to 10 of the present technology is different from that of the battery module 1 of embodiment 1 of the present technology, so the same structure as that of the battery module 1 of embodiment 1 of the present technology is not repeated. In addition, in the following embodiments, the case where an adhesive layer is configured and the case where no adhesive layer is configured are illustrated, but the adhesive layer is not required. In addition, matching the description of each embodiment, at least one state of the spacer before and after the compression deformation is shown. (Implementation method 2)

[0134] Fig.10 2 is a cross-sectional view showing the structure of a battery module according to Embodiment 2 of the present technology. Fig.10 As shown, the battery module according to the second embodiment of the present technology includes a battery cell 100, an end plate, a restraint member, a spacer 400A, and an adhesive layer 500. The spacer 400A includes an elastic body 410A.

[0135] The first portion 411A of the elastic body 410A abuts against at least one battery cell 100a among the plurality of battery cells 100 at a first abutting surface 412A in the first direction (Y direction). The first abutting surface 412A has a concavo-convex shape.

[0136] In the battery module of embodiment 2 of the present technology, the elastomer 410A is brought into contact with the battery cell 100a by the convex portion of the concave-convex shape of the first abutting surface 412A. Compared with the case of abutting with a plane, the abutting pressure can be increased, thereby achieving a structure in which the internal pressure of the enclosed space 11 is not easily released from the abutting position to the outside. (Implementation method 3)

[0137] Fig.11 2 is a cross-sectional view showing the structure of a battery module according to Embodiment 3 of the present technology. Fig.11 As shown, the battery module according to the third embodiment of the present technology includes a battery cell 100, an end plate, a restraining member, a spacer 400B, a first adhesive layer 501B, and a second adhesive layer 502B. The spacer 400B includes an elastic body 410B.

[0138] The first portion 411B of the elastic body 410B abuts against at least one battery cell 100a among the plurality of battery cells 100 at a first abutting surface 412B in the first direction (Y direction). The first abutting surface 412B has a concavo-convex shape.

[0139] The first portion 411B is bonded to the other of the two battery cells 100b via the first adhesive layer 501B at the end opposite to the first abutting surface 412B. The first portion 411B is bonded to one of the battery cells 100a via the second adhesive layer 502B at the first abutting surface 412B.

[0140] In the battery module of embodiment 3 of the present technology, the elastomer 410B is brought into contact with the battery cell 100 by the convex portion of the concave-convex shape of the first abutting surface 412B, so that the abutting pressure can be increased compared to the case of abutting with a plane, and the first abutting surface 412B is firmly fixed to the battery cell 100 by the second adhesive layer 502B, thereby achieving a structure in which the internal pressure of the enclosed space is not easily released from the abutting position to the outside. (Implementation method 4)

[0141] Fig.12 2 is a cross-sectional view showing the structure of a battery module according to a fourth embodiment of the present technology. Fig.12 As shown, the battery module according to the fourth embodiment of the present technology includes the battery cells 100, end plates, restraint members, and a spacer 400C. The spacer 400C includes an elastic body 410C.

[0142] The first portion 411C of the elastic body 410C abuts against at least one battery cell 100a among the plurality of battery cells 100 at a first abutting surface 412C in the first direction (Y direction). The first abutting surface 412C has a convex shape.

[0143] In the battery module of embodiment 4 of the present technology, by making the elastomer 410C abut against the battery cell 100 in the convex shape of the first abutting surface 412C, the abutting pressure can be increased compared to the case of a flat abutment, thereby achieving a structure in which the internal pressure of the enclosed space 11 is not easily released to the outside from the abutment position. (Implementation method 5)

[0144] Fig.13 2 is a cross-sectional view showing the structure of a battery module according to Embodiment 5 of the present technology. Fig.13 As shown, the battery module according to the fifth embodiment of the present technology includes the battery cells 100, end plates, restraint members, and a spacer 400D. The spacer 400D includes an elastic body 410D.

[0145] The first portion 411D of the elastic body 410D abuts against one of the two battery cells 100 sandwiching the spacer 400D among the plurality of battery cells 100 at the first abutting surface 412D.

[0146] The width of the first portion 411D becomes narrower as it extends from the other one 100 b toward the one one 100 a of the two battery cells in the first direction (Y direction).

[0147] In the battery module of embodiment 5 of the present technology, by narrowing the width of the elastic body 410D from one end in the first direction (Y direction) toward the other end, it is possible to obtain a structure that is easy to elastically deform and to increase the pressure in the enclosed space at the beginning of the elastic deformation of the elastic body 410D. (Implementation method 6)

[0148] Fig.14 2 is a cross-sectional view showing the structure of a battery module according to Embodiment 6 of the present technology. Fig.14 As shown, the battery module according to the sixth embodiment of the present technology includes the battery cells 100, end plates, restraint members, and a spacer 400E. The spacer 400E includes an elastic body 410E.

[0149] The first portion 411E of the elastic body 410E has a main portion 413E and a tapered portion 414E. The width of the main portion 413E in a direction orthogonal to the first direction (Y direction) is wider than that of the tapered portion 414E. In addition, the first portion 411E may be narrowed in multiple stages from one side to the other side in the first direction (Y direction).

[0150] In the battery module of the sixth embodiment of the present technology, the first portion 411E has the tapered portion 414E narrower than the main portion 413E, so that the elastic body 410E can be easily elastically deformed at the start of elastic deformation and the pressure of the closed space can be easily increased. (Implementation method 7)

[0151] Fig.15 2 is a cross-sectional view showing the structure of a battery module according to Embodiment 7 of the present technology. Fig.15 As shown, the battery module according to the seventh embodiment of the present technology includes a battery cell 100, an end plate, a restraint member, and a spacer 400F. The spacer 400F includes an elastic body 410F.

[0152] The elastic body 410F has a first portion 411F and a connecting portion 420F. The connecting portion 420F is located at an end of the first portion 411F in the first direction (Y direction). In the present embodiment, the connecting portion 420F contacts the battery cell 100 .

[0153] The connecting portion 420F connects the peripheries of the frame shape of the first portion 411F. In the present embodiment, the connecting portion 420F connects the entire periphery of the frame shape of the first portion 411F. In addition, the connecting portion 420F is not limited to this structure. For example, the connecting portion 420F may be a mesh shape when viewed from the first direction (Y direction) in a manner that connects a portion of the periphery of the frame shape.

[0154] In the battery module of embodiment 7 of the present technology, the frame shape of the first part 411F is connected to the periphery of the frame shape by using the connecting portion 420F. When the spacer 400 is arranged between the battery cells 100 by holding the spacer 400, the frame shape of the first part 411F is not easily deformed, so the spacer 400 can be easily handled. (Implementation method 8)

[0155] Fig.16 2 is a cross-sectional view showing the structure of a battery module according to an eighth embodiment of the present technology. Fig.16 As shown, the battery module according to the eighth embodiment of the present technology includes the battery cell 100, the end plate, the restraint member, and the spacer 400G. The spacer 400G includes an elastic body 410G and a heat insulating material 430G.

[0156] The heat insulating material 430G is arranged in the closed space 10 of the elastic body 410G. The heat insulating material 430G contains air inside and exerts a high heat insulating function. The heat insulating material 430G is composed of, for example, a porous body or glass fiber. In addition, the heat insulating material 430G can also be composed of an inorganic filler (for example, ceramics such as alumina) and a polymer material.

[0157] In the battery module of embodiment 8 of the present technology, by configuring the insulating material 430G in the enclosed space 10 of the elastomer 410G, compared with the case where the elastomer 410G and the insulating material 430G are configured to overlap in the first direction (Y direction), the spacer 400G can be given a reaction force relative to the battery cell 100 and a heat insulation function without increasing the thickness of the spacer 400G. (Implementation method 9)

[0158] Fig.17 This is a cross-sectional view showing the structure of a spacer in a battery module according to Embodiment 9 of the present technology when the spacer is in a no-load state. Fig.18 Observe from the direction of the arrow on line XVIII-XVIII Fig.17 A cross-sectional view of a battery module. Fig.19 This is a cross-sectional view showing a structure of a battery module according to Embodiment 9 of the present technology in a state where a spacer is compressed and deformed.

[0159] like Figure 17~Figure 19As shown, the battery module according to the ninth embodiment of the present technology includes a battery cell 100, an end plate, a restraining member, and a spacer 400H. The spacer 400H includes an elastic body 410H.

[0160] The elastic body 410H has a first portion 440H and a second portion 450H. The first portion 440H abuts against at least one battery cell 100 a among the plurality of battery cells 100 at a first abutting surface 441H in the first direction (Y direction).

[0161] The second portion 450H is located outside the first portion 440H when viewed from the first direction (Y direction) and has a frame shape extending around the axis of the first direction (Y direction).

[0162] The second portion 450H abuts against at least one battery cell 100 a among the plurality of battery cells 100 at the second abutting surface 451H in the first direction (Y direction).

[0163] A gap G is provided between the first portion 440H and the second portion 450H in a direction perpendicular to the first direction (Y direction). In the present embodiment, a gap G is provided between the first portion 440H and the second portion 450H over the entire circumference in the axial direction of the first direction (Y direction).

[0164] The first portion 440H has a first width W1 of a portion of the frame shape in a direction perpendicular to the first direction at an end portion on the opposite side to the first contact surface 441H in the first direction (Y direction).

[0165] The second portion 450H has a second width W2 of a portion of the frame shape in a direction perpendicular to the first direction at an end portion on the opposite side to the second contact surface 451H in the first direction (Y direction). The second width W2 is wider than the first width W1.

[0166] like Fig.19 As shown, in the first direction (Y direction), the thickness t of the second portion 450H in contact with at least one battery cell 100 is substantially the same as the thickness T of the first portion 440H disposed between the plurality of battery cells 100 and elastically deformed in the compression direction.

[0167] In the battery module according to the ninth embodiment of the present technology, since the elastic body 410H has the first portion 440H and the second portion 450H, the sealed space 10 can be defined by the first portion 440H and the battery cell 100 can be supported by the second portion 450H.

[0168] In the battery module of embodiment 9 of the present technology, by setting a gap G between the first part 440H and the second part 450H, when the first part 440H tilts toward the second part 450H when the elastic body 410H is compressed and deformed, the first part 440H can be structured so that it is not easy for the first part 440H to interfere with the second part 450H.

[0169] In the battery module of embodiment 9 of the present technology, by making the second width W2 of the second part wider than the first width W1 of the first part 440H, the first part 440H for sealing the interior of the elastomer 410H is easily deformed and the second part 450H for maintaining the compressed pressure is not easy to topple over, thereby easily ensuring the pressure of the enclosed space 10 of the elastomer 410H. (Implementation 10)

[0170] Fig. 20 This is a cross-sectional view showing the structure of a spacer in a battery module according to a tenth embodiment of the present technology when it is in a no-load state. Fig.21 This is a cross-sectional view showing a structure of a battery module according to a tenth embodiment of the present technology in a state where a spacer is compressed and deformed.

[0171] like Fig. 20 and 21 As shown, the battery module according to the tenth embodiment of the present technology includes a battery cell 100, an end plate, a restraint member, and a spacer 400I. The spacer 400I includes an elastic body 410I.

[0172] The elastic body 410I includes a first portion 440I and a second portion 450I. The first portion 440I contacts one of two battery cells 100a sandwiching the spacer 400I among the plurality of battery cells 100 at a first contact surface 441I in the first direction (Y direction).

[0173] The second portion 450I is located outside the first portion 440I when viewed from the first direction (Y direction) and has a frame shape extending around the axis of the first direction (Y direction).

[0174] The second portion 450I abuts against at least one battery cell 100 a among the plurality of battery cells 100 at the second abutting surface 451I in the first direction (Y direction).

[0175] The first portion 440I has a tapered surface 442I. The tapered surface 442I faces the second portion 450I and, in a no-load state, tilts from the outside to the inside of the axis around the first direction (Y direction) as it moves from the other side 100b to the one side 100a of the plurality of battery cells 100. When a load is applied to the first portion 440I, the load is applied obliquely, so that it is easy to tilt inward.

[0176] In the battery module of embodiment 10 of the present technology, a conical surface 442I is provided on the side of the first part 440I facing the second part 450I, so that when the elastomer 410I is compressed and deformed, the first part 440I can be easily tilted inward, thereby achieving a structure in which the first part 440I and the second part 450I are not easily interfered with.

[0177] In addition, in each embodiment, the spacer disposed between the plurality of battery cells is described, but the spacer disposed between the battery cell and the end plate can also be applied with the same structure as the above-mentioned spacer. In addition, in this specification, the same size means the same size of the design value without including the manufacturing tolerance.

[0178] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A battery module, wherein: The battery module comprises: a plurality of battery cells arranged in a first direction; and a spacer, the spacer being located between the plurality of battery cells, The spacer includes an elastic body capable of elastic deformation at least in the first direction, The elastic body has a first portion, the first portion having a frame shape extending around an axis in the first direction and defining a closed space inside. In the first direction, a thickness of the first portion in an unloaded state is 1.30 to 2.87 times greater than a thickness of the first portion disposed between the plurality of battery cells and elastically deformed in a compression direction.

2. The battery module according to claim 1, wherein: The first portion abuts against at least one battery cell among the plurality of battery cells at a first abutting surface in the first direction, The first abutting surface has a concavo-convex shape.

3. The battery module according to claim 2, wherein: The first portion abuts against one of two battery cells sandwiching the spacer among the plurality of battery cells at the first abutting surface. The width of the first portion becomes narrower as it moves from the other of the two battery cells toward the one of the two battery cells in the first direction.

4. The battery module according to any one of claims 1 to 3, wherein: The elastic body further includes a connecting portion, which is located at an end of the first portion in the first direction and connects the peripheral edges of the frame shape of the first portion.

5. The battery module according to claim 1 or 2, wherein: The elastic body further includes a second portion, the second portion being located outside the first portion when viewed from the first direction and having a frame shape extending around an axis in the first direction, The second portion abuts against at least one battery cell among the plurality of battery cells at a second abutting surface in the first direction, In the first direction, the thickness of the second portion in contact with the at least one battery cell is substantially the same as the thickness of the first portion disposed between the plurality of battery cells and elastically deformed in the compression direction.

6. The battery module according to claim 5, wherein: In a direction orthogonal to the first direction, a gap is provided between the first portion and the second portion.

7. The battery module according to claim 1, wherein: The elastic body further includes a second portion, the second portion being located outside the first portion when viewed from the first direction and having a frame shape extending around an axis in the first direction, The first portion abuts against at least one battery cell among the plurality of battery cells at a first abutting surface in the first direction, The second portion abuts against the at least one battery cell at a second abutting surface in the first direction, The first portion has a first width of a portion of the frame shape in a direction perpendicular to the first direction at an end portion on the side opposite to the side where the first abutting surface is located in the first direction. The second portion has a second width of a portion of the frame shape in a direction perpendicular to the first direction at an end portion on the side opposite to the side where the second abutting surface is located in the first direction. The second width is wider than the first width.

8. The battery module according to claim 1, wherein: The elastic body further includes a second portion, the second portion being located outside the first portion when viewed from the first direction and having a frame shape extending around an axis in the first direction, The first portion abuts against one of two battery cells sandwiching the spacer among the plurality of battery cells at a first abutting surface. The first portion has a tapered surface that faces the second portion and inclines from an outer side to an inner side of an axis around the first direction as it moves from the other side to the one side of the plurality of battery cells in a no-load state.

9. The battery module according to claim 1 or 2, wherein: The spacer also includes a heat insulating material which is disposed in the enclosed space and has an inner space.

10. The battery module according to claim 1 or 2, wherein: The battery module further includes an adhesive layer that bonds the elastic body and the plurality of battery cells in the first direction.

Images