Monomer laminate and battery module

Abstract

The present invention provides a single cell laminate and a storage battery module that suppress dimensional changes in the stacking direction of battery cells even when the battery cells expand. In a single cell laminate (10) formed by stacking a plurality of battery cells (11), the plurality of battery cells (11) are stacked in the X direction and are stacked offset to one side in the Y direction orthogonal to the X direction. In addition, an elastomer (12) is disposed between adjacent battery cells (11) of the plurality of battery cells (11). The elastomer (12) is configured to displace the battery cell (11) in the X direction and displace it to the other side in the Y direction when the battery cell (11) expands.

Description

Technical Field

[0001] The present invention relates to a single-layer laminate and a battery module including the single-layer laminate. Background Art

[0002] In recent years, as a concrete measure to address global climate change, initiatives to achieve a low-carbon society or a decarbonized society have been very active. In mobile bodies equipped with a drive source such as vehicles, there has also been a strong demand to reduce CO2 emissions, and the electrification of the drive source has been rapidly developing. For example, as vehicles, the development of vehicles such as electric vehicles (EVs) or hybrid electric vehicles (HEVs), which are equipped with an electric motor as a drive source of the vehicle and a storage battery as a secondary battery that can supply power to the electric motor, is being promoted. Such a storage battery generally includes a single-layer laminate formed by stacking a plurality of battery cells.

[0003] However, the battery cells expand or contract according to the usage conditions (e.g., charge state). In particular, in the case of using a so-called all-solid-state battery as the battery cell, the expansion and contraction are more significant. Therefore, the following technique is disclosed in Patent Document 1 below: In a case where a laminate formed of all-solid-state battery cells is housed in a housing, two contact portions that are respectively in contact with both ends in the stacking direction of the laminate and two spring structures that connect the two contact portions are provided. Thus, when the laminate expands, the spring structures are expanded, and the major axis of the housing is elongated to the thickness of the expanded laminate, so that an excessive pressure is not applied to the laminate.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-155356 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] When considering mounting the single-layer laminate on an arbitrary machine such as a vehicle, it is desirable to suppress dimensional changes in the stacking direction of the battery cells even when the battery cells expand. However, in the prior art, there is still room for improvement in this regard.

[0009] The present invention provides a technique capable of suppressing dimensional changes in the stacking direction of the single-layer laminate even when the battery cells expand.

[0010] Means for Solving the Problems

[0011] A first invention provides a single-layer laminate formed by stacking a plurality of battery cells, wherein,

[0012] The plurality of battery cells are stacked in a first direction and are offset and stacked toward one side in a second direction orthogonal to the first direction.

[0013] An elastomer is disposed between adjacent battery cells of the plurality of battery cells.

[0014] The elastomer is configured to displace the battery cell in the first direction and displace it toward the other side in the second direction when the battery cell expands.

[0015] A second invention provides a storage battery module, wherein

[0016] The storage battery module includes:

[0017] The single-cell laminate as described above; and

[0018] A housing that houses the single-cell laminate.

[0019] The housing is configured to have a parallelogram shape when viewed from a third direction, and displace the battery cell in the first direction and displace it toward the other side in the second direction when the battery cell expands.

[0020] Advantageous Effects of the Invention

[0021] According to the present invention, even when the battery cell expands, it is possible to suppress a change in the size of the single-cell laminate in the stacking direction of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is a view of the single-cell laminate 10 viewed from the Z direction.

[0023] Figure 2 FIG. is a view of the single-cell laminate 10 viewed from the Y direction.

[0024] Figure 3 FIG. is an enlarged view of the elastomer 12 of the single-cell laminate 10 viewed from the Z direction.

[0025] Figure 4 FIG. is a view showing an example of displacement of the battery cell 11 accompanying expansion and contraction of the battery cell 11 in the single-cell laminate 10.

[0026] Figure 5 FIG. is a view of the storage battery module 100 including the single-cell laminate 10 viewed from the Z direction.

[0027] Figure 6 FIG. is a view of the storage battery module 100 including the single-cell laminate 10 viewed from the Y direction.

[0028] Figure 7This is a diagram showing a modified example of the battery module 100 that accompanies the expansion and contraction of the battery cell 11.

[0029] Figure 8 This is a diagram showing another modified example of the battery module 100 that accompanies the expansion and contraction of the battery cell 11.

[0030] Explanation of reference numerals:

[0031] 10 Monomer laminate

[0032] 11 Battery cell

[0033] 12 Elastomer

[0034] 12a Bottom edge

[0035] 12b Hypotenuse

[0036] 13 Elastomer block

[0037] 100 Battery module

[0038] 110 Housing. Detailed implementation mode

[0039] Hereinafter, an embodiment of the monomer laminate of the present invention and the battery module including the monomer laminate will be described in detail with reference to the drawings. It should be noted that the drawings are views observed from the direction of the reference numerals.

[0040] [Monomer laminate]

[0041] As Figure 1 and Figure 2 shown, the monomer laminate 10 of the present embodiment includes a plurality of battery cells 11 arranged so as not to contact each other and an elastomer 12 disposed between adjacent battery cells 11 of these plurality of battery cells 11. Among them, the elastomer 12 is provided in a state fixed to the battery cell 11, for example, adhered to the battery cell 11.

[0042] The battery cell 11 is formed using, for example, an all-solid-state battery. The all-solid-state battery includes a positive electrode for an all-solid-state battery, a negative electrode for an all-solid-state battery, and a solid electrolyte disposed between the positive electrode for an all-solid-state battery and the negative electrode for an all-solid-state battery, and illustration thereof is omitted. The all-solid-state battery is charged and discharged by the transfer of lithium ions between the positive electrode for an all-solid-state battery and the negative electrode for an all-solid-state battery via the solid electrolyte. The solid electrolyte is not particularly limited as long as it has lithium ion conductivity and insulation properties, and generally, materials used for all-solid-state lithium ion batteries can be used. For example, as the solid electrolyte, sulfide solid electrolyte materials, oxide solid electrolyte materials, inorganic solid electrolytes such as lithium salt-containing materials, polymer-based solid electrolytes such as polyethylene oxide, and gel-based solid electrolytes containing lithium salt and having lithium ion conductivity ionic liquids can be cited. The form of the solid electrolyte material is not particularly limited, and for example, a particulate form can be cited.

[0043] In the monomer laminate 10, a plurality of battery cells 11 are laminated in a first direction and are laminated offset to one side in a second direction orthogonal to the first direction. That is, the first direction is the lamination direction of the battery cells 11 in the monomer laminate 10. Hereinafter, the first direction will also be referred to as the "X direction", one side in the X direction will also be referred to as the "X1 direction", and the other side in the X direction will also be referred to as the "X2 direction". In addition, the second direction orthogonal to the first direction (i.e., the X direction) will also be referred to as the "Y direction", one side in the Y direction will also be referred to as the "Y1 direction", and the other side in the Y direction will also be referred to as the "Y2 direction". Moreover, the third direction orthogonal to the first direction (i.e., the X direction) and the second direction (i.e., the Y direction) will also be referred to as the "Z direction".

[0044] When viewed from the Z direction, the elastic body 12 is a cushioning material having a parallelogram shape formed by a pair of bottom sides 12a extending in the Y direction and a pair of hypotenuse sides 12b extending in the Y1 direction as it approaches the X1 direction. The elastic body 12 is made of an elastic material such as resin or rubber. As the resin, for example, it is an elastomer of a silicone-based, fluorine-based, urethane-based, amide-based, olefin-based, styrene-based, ester-based, or vinyl chloride-based type. The urethane-based, amide-based, olefin-based, and ester-based types are hard and can easily ensure the load surface pressure. The amide-based, styrene-based, urethane-based, ester-based, and vinyl chloride-based types have a high resilience coefficient. The urethane-based elastomer has a lower cost compared to rubber and other elastomers, can easily ensure the load surface pressure, and also has a relatively high rebound coefficient, and is thus most preferred in this regard. By making the elastic body 12 an elastomer, the expansion or contraction of the battery cell 11 can be appropriately absorbed. In addition, by appropriately selecting the material of the elastomer in consideration of the resilience of the elastic body 12 and the ambient temperature of the environment in which the elastic body 12 is used, an appropriate pressure can be applied to the expanded battery cell 11, and the elastic body 12 can be formed inexpensively and easily.

[0045] Specifically, as Figure 3 shown, the elastomer 12 is formed by laminating a plurality of parallelogram-shaped elastomer blocks 13 having a pair of bottom sides 13a extending in the Y direction and a pair of hypotenuse sides 13b extending in the Y1 direction as approaching the X1 direction in the Y direction. Thereby, the elastomer 12 having the aforementioned parallelogram shape can be easily formed. It should be noted that, for example, the aforementioned elastic polymer can be used for the elastomer block 13. Thereby, the elastomer block 13 can be formed inexpensively and easily, and the manufacturing cost of the monomer laminate 10 can be reduced.

[0046] According to the monomer laminate 10 configured as described above, as Figure 4 shown, when the battery cell 11 expands, the battery cell 11 is displaced in the X direction and also displaced in the Y2 direction (refer to the arrow of reference numeral 400 in Figure 4 ).

[0047] Specifically, for example, restraint members (such as end plates, side walls of a housing that houses the monomer laminate 10) (not shown) are provided on both sides in the X direction of the monomer laminate 10, and when the monomer laminate 10 expands in the X direction, a reaction force is received from the restraint members. Therefore, when the battery cell 11 expands, correspondingly, the elastomer 12 disposed between the battery cells 11 is flattened. Thereby, even when the battery cell 11 expands, an excessive pressure can be prevented from being applied to the battery cell 11. In addition, by the restoring force of the elastomer 12, an appropriate pressure can be applied to the battery cell 11 to restrain the battery cell 11.

[0048] Moreover, by flattening the elastomer 12 in this way, the battery cell 11 is displaced in the X direction and also displaced in the Y2 direction. That is, the elastomer 12 deforms as the battery cell 11 expands, and thus functions as a displacement direction guiding portion that guides the battery cell 11 to be displaced in the Y2 direction.

[0049] Moreover, as Figure 4 shown, the monomer laminate 10 is configured such that when the battery cells 11 are at maximum expansion, the offset in the Y direction between the battery cells 11 is substantially zero, and each battery cell 11 is arranged straight in the X direction. In other words, the monomer laminate 10 is configured such that when the battery cells 11 are not at maximum expansion, the battery cells 11 are offset from each other in the Y direction.

[0050] As described above, according to the single-layer laminate 10, due to the deformation of the elastic body 12 caused by the expansion of the battery cell 11, the battery cell 11 is displaced in the X direction and in the Y2 direction. Thereby, compared with the case where the non-expanding battery cell 11 is not displaced in the Y2 direction, the displacement of the battery cell 11 in the X direction can be reduced. Therefore, even if the battery cell 11 expands according to the usage condition (e.g., charge state), the dimensional change of the single-layer laminate 10 in the stacking direction of the battery cells 11 (i.e., the X direction) can be suppressed. Moreover, by suppressing the dimensional change of the single-layer laminate 10 in the stacking direction of the battery cells 11, it is easy to mount the single-layer laminate 10 on any machine such as a vehicle.

[0051] In addition, according to the single-layer laminate 10, even if the battery cell 11 expands and contracts, its displacement can be efficiently absorbed through the deformation of the elastic body 12. Therefore, the volume (dead space) occupied by components other than the battery cell 11 in the single-layer laminate 10 can be reduced, and the energy density of the single-layer laminate 10 can also be increased.

[0052] [Battery module]

[0053] Next, an example of a battery module including the above single-layer laminate 10 will be described. It should be noted that hereinafter, the same reference numerals will be given to the same parts as those described above, and their descriptions will be appropriately omitted or simplified.

[0054] As Figure 5 and Figure 6 shown, the battery module 100 includes a single-layer laminate 10 and a housing 110 that houses the single-layer laminate 10. When viewed from the Z direction, the housing 110 has a parallelogram shape formed by a pair of bottom edges 110a extending in the Y direction and a pair of oblique edges 110b extending in the Y2 direction as it approaches the X1 direction. Thereby, as Figure 5 shown, the shape of the housing 110 when viewed from the Z direction can be made to coincide with the shape of the single-layer laminate 10, and the dead space generated when the housing 110 houses the single-layer laminate 10 can be reduced.

[0055] In addition, the housing 110 is made of, for example, a laminated film in which a resin layer and a metal layer are laminated, and it deforms as the battery cell 11 of the single-layer laminate 10 housed therein is displaced. In other words, the housing 110 does not hinder the displacement of the battery cell 11 of the single-layer laminate 10 housed therein.

[0056] Therefore, as Figure 7As shown, in the battery module 100 that houses the monomer laminate 10 in the housing 110, when the battery cell 11 expands, the battery cell 11 also displaces in the X direction and in the Y2 direction. Thereby, compared with the case where the expanding battery cell 11 does not displace in the Y2 direction, the displacement of the battery cell 11 in the X direction can be reduced. Therefore, even if the battery cell 11 expands according to the usage condition (e.g., charge state), the dimensional change of the battery module 100 in the stacking direction (i.e., X direction) of the battery cells 11 can be suppressed. Moreover, by suppressing the dimensional change of the battery module 100 in the stacking direction of the battery cells 11, it is easy to mount the battery module 100 on any machine such as a vehicle.

[0057] In addition, as Figure 8 shown, for example, if control is performed on the basis of arranging a plurality of battery modules 100 in the Y direction so that the usage conditions and the like of each battery module 100 are the same, each battery module 100 (each monomer laminate 10) can be deformed in the same way. Therefore, it is possible to effectively use the limited space to arrange a plurality of battery modules 100. Thereby, for example, an increase in the energy density of a battery pack or the like formed by arranging a plurality of battery modules 100 in the Y direction can be achieved.

[0058] Of course, although one embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the described embodiment. Obviously, those skilled in the art can conceive various modification examples or correction examples within the scope described in the technical solution, and it should be understood that these modification examples and correction examples also belong to the technical scope of the present invention. In addition, within the scope not departing from the gist of the invention, the constituent elements in the above-described embodiments can be arbitrarily combined.

[0059] For example, in the above-described embodiment, an example in which the elastic body 12 is formed by stacking a plurality of elastic body blocks 13 in the Y direction has been described, but the present invention is not limited thereto. For example, the elastic body 12 can be constituted by one cushioning material having a parallelogram shape, or the elastic body 12 can be constituted by a plate material formed in a substantially Z shape, and the substantially Z shape has a pair of bottom sides extending in the Y direction when viewed from the Z direction and one side connecting the pair of bottom sides to each other and extending in the Y1 direction as it approaches the X1 direction.

[0060] In addition, in the above-described embodiment, an example in which the battery cell 11 is constituted by a all-solid-state battery has been described, but the present invention is not limited thereto. The battery cell 11 can also be constituted by any type of secondary battery that expands and contracts according to the usage condition, such as a lithium-ion battery.

[0061] The following matters are at least described in this specification. In parentheses, corresponding components, etc. in the above-described embodiments are shown as an example, but the present invention is not limited thereto.

[0062] (1) A monomer laminate (monomer laminate 10) formed by laminating a plurality of battery monomers (battery monomer 11), wherein

[0063] the plurality of battery monomers are laminated in a first direction (X direction), and are laminated with an offset to one side in a second direction (Y direction) orthogonal to the first direction,

[0064] an elastomer (elastomer 12) is disposed between adjacent battery monomers of the plurality of battery monomers,

[0065] the elastomer is configured to displace the battery monomer in the first direction and displace to the other side in the second direction when the battery monomer expands.

[0066] According to (1), due to the deformation of the elastomer generated by the expansion of the battery monomer, the battery monomer can be displaced in the second direction. Therefore, compared with the case where the expanded battery monomer is not displaced in the second direction, the displacement of the battery monomer in the first direction can be reduced. Thus, even when the battery monomer expands, the dimensional change of the monomer laminate in the lamination direction of the battery monomers can be suppressed.

[0067] (2) The monomer laminate according to (1), wherein

[0068] when viewed from a third direction orthogonal to the first direction and the second direction, the elastomer has a parallelogram shape formed by a pair of bottom sides (bottom side 12a) extending in the second direction and a pair of hypotenuse sides (hypotenuse side 12b) extending to the one side in the second direction as it approaches the first direction.

[0069] According to (2), due to the deformation of the elastomer generated by the expansion of the battery monomer, the battery monomer can be displaced in the second direction.

[0070] (3) The monomer laminate according to (2), wherein

[0071] the elastomer is formed by laminating a plurality of elastomer blocks (elastomer block 13) having the parallelogram shape in the second direction.

[0072] According to (3), an elastomer having a parallelogram shape can be easily formed.

[0073] (4) The monomer laminate according to (2), wherein

[0074] The elastomer is made of a cushioning material.

[0075] According to (4), the elastomer can be formed inexpensively and easily, and the manufacturing cost of the single-layer laminate can be reduced.

[0076] (5) The single-layer laminate according to (4), wherein

[0077] The cushioning material is an elastic polymer.

[0078] According to (5), the expansion or contraction of the battery cell can be appropriately absorbed.

[0079] (6) The single-layer laminate according to (5), wherein

[0080] The elastic polymer is any one of silicone-based, fluorine-based, urethane-based, amide-based, olefin-based, styrene-based, ester-based, and vinyl chloride-based elastic polymers.

[0081] According to (6), the expansion or contraction of the battery cell can be absorbed more appropriately.

[0082] (7) A storage battery module (storage battery module 100), wherein

[0083] The storage battery module includes:

[0084] (2) to (6) any one of the single-layer laminates described above; and

[0085] A housing (housing 110) that houses the single-layer laminate,

[0086] The housing is configured to have the parallelogram shape when viewed from the third direction, and when the battery cell expands, the battery cell is displaced in the first direction and displaced to the other side in the second direction.

[0087] According to (7), even if the battery cell expands, the dimensional change of the storage battery module in the stacking direction of the battery cells can be suppressed.

Claims

1. A single - cell laminate formed by laminating a plurality of battery cells, wherein, the plurality of battery cells are laminated in a first direction and are laminated with an offset to one side in a second direction orthogonal to the first direction, an elastomer is disposed between adjacent battery cells of the plurality of battery cells, the elastomer is configured to displace the battery cell in the first direction and displace the battery cell to the other side in the second direction when the battery cell expands.

2. The single - cell laminate according to claim 1, wherein, when viewed from a third direction orthogonal to the first direction and the second direction, the elastomer has a parallelogram shape formed by a pair of bottom sides extending in the second direction and a pair of oblique sides extending in the second direction toward the one side as it approaches the first direction.

3. The single - cell laminate according to claim 2, wherein, the elastomer is formed by laminating a plurality of elastomer blocks having the parallelogram shape in the second direction.

4. The single - cell laminate according to claim 2, wherein, the elastomer is made of a cushioning material.

5. The single - cell laminate according to claim 4, wherein, the cushioning material is an elastic polymer.

6. The single - cell laminate according to claim 5, wherein, the elastic polymer is any one of silicone - based, fluorine - based, urethane - based, amide - based, olefin - based, styrene - based, ester - based, and vinyl chloride - based elastic polymers.

7. A storage battery module, wherein, the storage battery module includes: the single - cell laminate according to any one of claims 2 to 6; and a housing that houses the single - cell laminate, the housing is configured to have the parallelogram shape when viewed from the third direction, and displace the battery cell in the first direction and displace the battery cell to the other side in the second direction when the battery cell expands.

Images