Battery case

Abstract

Provided is a battery case in which cylindrical battery cells can be appropriately contained. A battery case 1 according to the present disclosure comprises a plurality of container portions 11 in each of which one cylindrical battery cell can be contained, the container portions 11 being arrayed in one direction. The container portions 11 each include a wall portion 12 defining a space for containing the cylindrical battery cell. The wall portion 12 in the state before the cylindrical battery cell is contained therein defines an elliptical-columnar space. When the direction in which the container portions 11 are arranged in one direction is the major-axis direction of the elliptical-columnar space, a direction perpendicular to the major-axis direction is the minor-axis direction, and a direction perpendicular to the major-axis direction and the minor-axis direction and parallel to a central axis C of the space of the elliptical-columnar space is the depth direction, the greatest major axis diameter L1 in the major-axis direction of the elliptical-columnar space in the container portion 11 is greater than the diameter of the cylindrical battery cell.

Description

[Technical Field]

[0001] The present disclosure relates to a battery case. [Background technology]

[0002] Patent Document 1 describes a battery holder that holds multiple cylindrical batteries in an aligned state, and has multiple cylindrical battery storage sections that respectively store each battery, with each battery storage section formed by a roughly cylindrical wall section that has spring properties that allow it to expand in diameter when a battery is inserted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-207569 Summary of the Invention [Problem to be solved by the invention]

[0004] It is technically known that cylindrical batteries have dimensional tolerances. Therefore, when a cylindrical battery that is larger than the dimensional tolerance is stored in a battery housing section that can expand in diameter, the battery housing section expands in diameter and deforms in accordance with the size of the cylindrical battery. This expansion and deformation of the battery housing section affects other adjacent battery housing sections. For example, if one battery housing section expands in diameter and deforms due to the storage of a battery, the other battery housing sections adjacent to the first battery housing section will be deformed in shape due to the expansion and deformation of the first battery housing section. Depending on the degree of deformation, there is a risk that the other battery housing sections will not be able to properly store the cylindrical battery.

[0005] Therefore, a primary object of the present disclosure is to provide a battery case that can properly accommodate cylindrical battery cells. [Means for solving the problem]

[0006] The battery case according to the present disclosure comprises: A battery case having a plurality of storage sections each accommodating a single cylindrical battery cell, the storage sections being arranged in a line in one direction, the housing portion has a wall portion that defines a space for housing the cylindrical battery cell; the wall portion defines an elliptical cylindrical space before the cylindrical battery cell is housed therein; The direction in which the storage sections are arranged in one direction is defined as the long axis direction of the elliptical cylindrical space, the direction perpendicular to the long axis direction is defined as the short axis direction, and the direction perpendicular to the long axis direction and the short axis direction and parallel to the central axis of the elliptical cylindrical space is defined as the depth direction, The longest major axis diameter in the major axis direction of the elliptical cylindrical space in the storage section is equal to or greater than the diameter of the cylindrical battery cell. [Effects of the Invention]

[0007] The battery case of the present disclosure can provide a battery case that can properly accommodate cylindrical battery cells. Specifically, in the storage section having an elliptical cylindrical space, the longest major axis diameter of the elliptical cylindrical space in the major axis direction is equal to or greater than the diameter of the cylindrical battery cell, so that the cylindrical battery cell can be properly accommodated in the storage section even if the adjacent storage section experiences radial expansion deformation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically illustrating a first embodiment of a battery case according to the present disclosure. [Figure 2] 1 is a front view of a first embodiment of a battery case according to the present disclosure, viewed from the axial direction. [Figure 3] FIG. 10 is a front view of a battery case according to a modification of the first embodiment, viewed from the axial direction. [Figure 4] FIG. 2 is a perspective view schematically illustrating a second embodiment of a battery case according to the present disclosure. [Figure 5] FIG. 10 is a front view of a second embodiment of a battery case according to the present disclosure, viewed from the axial direction. [Figure 6] FIG. 10 is a perspective view schematically illustrating a third embodiment of a battery case according to the present disclosure. [Figure 7] FIG. 10 is a front view of a third embodiment of a battery case according to the present disclosure, viewed from the axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0009] A battery case according to an embodiment of the present disclosure will be described in more detail below. While the description will be made with reference to drawings as needed, the various elements in the drawings are merely shown schematically and for illustrative purposes to facilitate understanding of the present disclosure, and the appearance and dimensional ratios may differ from those of the actual product.

[0010] Various numerical ranges mentioned in this specification are intended to include the lower and upper limit numerical values ​​themselves, unless otherwise specified, such as "less than" or "more than / greater than." For example, a numerical range such as 1 to 10 can be interpreted as including the lower limit of "1" and the upper limit of "10." Furthermore, terms such as "about" and "approximately" mean that the range may include a variation of a few percent, for example, ±10%.

[0011] As used herein, the term "plan view" refers to the state when an object (e.g., a battery case) is placed and viewed from directly above in the thickness (height) direction, and is synonymous with a plan view. For example, the term "plan view" refers to the state when viewed along the negative direction in the "short axis direction" shown in FIG. 1. Unless otherwise specified, the term "side view" refers to the state when an object (e.g., a battery case) is placed and viewed from the side perpendicular to the thickness (height) direction, and is synonymous with a side view. For example, the term "side view" refers to the state when viewed along the negative direction (or positive direction) in the "long axis direction" shown in FIG. 1. Unless otherwise specified, the term "front view" refers to the state when an object (e.g., a battery case) is placed and viewed from the front perpendicular to the thickness (height) direction, and is synonymous with a front view. For example, the term "front view" refers to the state when viewed along the negative direction in the "depth direction" shown in FIG. 1. The above-mentioned "positive direction" refers to the direction of the arrows in the long axis direction, short axis direction, and depth direction shown in Figures 1 to 7, and the "negative direction" refers to the direction opposite to the direction of the arrows in the long axis direction, short axis direction, and depth direction shown in Figures 1 to 7.

[0012] -First embodiment of the battery case of the present disclosure- A first embodiment of a battery case according to the present disclosure will be described with reference to FIGS. 1 to 3. The battery case 1 includes a plurality of storage sections 11, each of which accommodates a single cylindrical battery cell. In FIG. 2, which shows an example, the number of storage sections 11 is five, but the number is not limited to the above example as long as it is two or more. As an example, the number of storage sections 11 may be two, as shown in FIG. 3. The storage sections 11 are arranged side by side in one direction. In this specification, the direction in which the storage sections 11 are arranged is defined as the long axis direction, and the direction perpendicular to the long axis direction is defined as the short axis direction. The direction perpendicular to the long axis direction and the short axis direction, which is parallel to the central axis of the cylindrical battery cell, is defined as the depth direction.

[0013] The storage section 11 has a wall 12 that defines a space for storing cylindrical battery cells. Before the cylindrical battery cells are stored in the storage section 11, the space is elliptical in front view. However, the shape of the space is not limited to an ellipse because the wall 12 is deformed by the cylindrical battery cells after the cylindrical battery cells are stored in the storage section 11. In FIG. 2 , which shows an example, the elliptical storage section 11 has a major axis diameter L1 and a minor axis diameter L2. In this specification, the "major axis diameter L1" is synonymous with the longest length in the major axis direction of the elliptical storage section 11 before the cylindrical battery cells are stored in the storage section 11, and the "minor axis diameter L2 of the ellipse" is synonymous with the longest length in the minor axis direction of the elliptical storage section 11 before the cylindrical battery cells are stored in the storage section 11. The major axis diameter L1 is longer than the minor axis diameter L2.

[0014] The depth direction length of the storage section 11 may be equal to or greater than the depth direction length of the cylindrical battery cells. By designing the depth direction length of the storage section 11 in this way, the contact area between the cylindrical battery cells stored in the storage section 11 and the wall section 12 of the storage section 11 increases, thereby improving heat transfer efficiency.

[0015] The walls 12 of adjacent storage sections 11 may be connected to each other. In other words, the walls 12 may be integrated as a single member. Designing the walls 12 in this manner makes it easier to handle the walls 12.

[0016] Any elastically deformable material may be used for the wall 12, but a resin material is preferred. The resin material preferably has the following material properties: a tensile strength of 15 MPa or more, a bending strength of 15 MPa or more, or a bending modulus of elasticity of 4000 MPa or less.

[0017] One characteristic feature of the battery pack 100 of the present disclosure is that the major axis diameter L1 of the elliptical cylindrical space provided in the housing section 11 is equal to or greater than the diameter of the cylindrical battery cell.

[0018] In this specification, the term "diameter of a cylindrical battery cell" refers not only to the diameter of the cylindrical battery cell as literally stated, but also to the maximum diameter dimension of the cylindrical battery cell with its dimensional tolerance. In this specification, the dimensional tolerance refers to a tolerance of ±2% of the diameter of the cylindrical battery cell.

[0019] According to the battery pack 100 of the present disclosure, when a cylindrical battery cell is accommodated in the accommodation section 11, the wall section 12 elastically deforms. Furthermore, because the major axis diameter L1 of the elliptical cylindrical space is equal to or greater than the diameter of the cylindrical battery cell, even if one cylindrical battery cell is accommodated in the accommodation section 11 and another cylindrical battery cell is accommodated in an adjacent accommodation section 11, deformation in the major axis direction of the accommodation section 11 accommodating the one cylindrical battery cell and deformation in the major axis direction of the accommodation sections 11 accommodating the other cylindrical battery cells can be suppressed. Therefore, the cylindrical battery cells can be accommodated appropriately in the accommodation sections 11.

[0020] The wall 12 may have a slit 13 formed parallel to the central axis C of the elliptical cylindrical space. Note that the "central axis of the elliptical cylindrical space" in this specification refers to an axis that passes through the center of the elliptical cylindrical space and extends parallel to the depth direction. In other words, the slit 13 is formed parallel to the depth direction. By providing the slit 13 in the wall 12, when a cylindrical battery cell is housed in the housing section 11, the minor axis diameter L2 is shorter than the major axis diameter L1, so the elliptical cylindrical space elastically deforms mainly in the minor axis direction. The elastic deformation generates an elastic force in the minor axis direction, and the cylindrical battery cell is sandwiched between the wall 12 in the minor axis direction. In other words, elastic deformation of the wall 12 in the major axis direction is suppressed.

[0021] In the present embodiment shown in FIG. 2 , the slits 13 are provided in the boundary region A between adjacent storage sections 11. In this specification, the term "boundary region" refers to the boundary position Ap between adjacent storage sections 11 and the region ranging from the boundary position Ap to a length ΔA that is ±10% of the major axis diameter L1. In the present embodiment shown in FIG. 2 , the slits 13 are provided in the boundary region A between adjacent storage sections 11 in storage sections 11 other than the central storage section 11, so that the entire area above the cylindrical battery cells can be covered by the wall section 12. Therefore, by providing the slits 13 in the boundary region A, the cylindrical battery cells can be properly brought into close contact with the wall section 12.

[0022] In addition, in the present embodiment shown in Figure 2, the slits 13 provided in the centrally located storage section 11 are positioned so as to overlap the central axis C of the storage section 11 in a plan view of the battery case 1. As mentioned above, the plan view refers to the state when viewed along the negative direction in the minor axis direction shown in Figure 1. Providing the slits 13 in this manner makes it easy to accommodate cylindrical battery cells in the centrally located storage section 11.

[0023] In the present embodiment shown in FIG. 2 , the slits 13 formed in the multiple housing sections 11 are plane-symmetrical with respect to a bisecting plane P of the battery case 1, which is parallel to the minor axis diameter L2 of the elliptical cylindrical space. The term "bisecting plane" used herein refers to a plane that includes a perpendicular bisector that bisects the length D (see FIG. 2 ) parallel to the major axis direction of the battery case 1 and is perpendicular to the major axis direction of the battery case 1. The term "plane-symmetrical" used herein refers to an object that, when cut along the bisecting plane P, has two halves that have substantially the same shape. By providing the slits 13 with plane symmetry, the elastic deformation of the wall sections 12 is symmetrical in the direction in which the housing sections 11 are arranged, thereby further improving the adhesion between the wall sections 12 and the cylindrical battery cells. This facilitates the transfer of heat generated by the cylindrical battery cells to the battery case 1, thereby further improving the heat dissipation of the cylindrical battery cells.

[0024] 2, the slits 13 formed in the plurality of housing portions 11 are positioned above the major axis diameter L1 of the ellipse in a front view (in the positive direction of the minor axis in FIG. 2). In other words, the slits 13 are positioned in the same direction (upper side) as the positive direction of the minor axis. By providing the slits 13 in this manner, the elastic deformation of the wall portions 12 can be aligned in the same direction, thereby generating appropriate elastic deformation.

[0025] Furthermore, in the present embodiment shown in FIG. 2, the minor axis diameter L2 is preferably a length that is 90% or more of the diameter of the cylindrical battery cell accommodated in the accommodation section 11. More preferably, it is preferably no more than 100% of the diameter of the cylindrical battery cell accommodated in the accommodation section 11. Having the minor axis diameter L2 as described above provides the following advantageous effects. The accommodation section 11 has a slit 13, and the minor axis diameter L2 is the above length. This allows the accommodation section 11 (wall 12) to elastically deform when the cylindrical battery cell is accommodated so that the space for accommodating the cylindrical battery cell expands to an extent that prevents the cylindrical battery cell from cracking. This prevents the battery case 1 (wall 12) from cracking when the cylindrical battery cell is accommodated in the accommodation section 11.

[0026] Furthermore, by setting the minor axis diameter L2 as described above, the contact area between the wall portion 12 and the surface of the cylindrical battery cell can be increased. First, as a comparative example, a case will be described in which the minor axis diameter L2 is a length that is less than 90% of the diameter of the cylindrical battery cell accommodated in the accommodation portion 11. In this case, when a cylindrical battery cell is accommodated in the accommodation portion 11, the width (length in the major axis direction) of the slit 13 is further expanded compared to this embodiment. In other words, the contact area between the wall portion 12 and the cylindrical battery cell is reduced. This makes it more difficult for heat generated from the cylindrical battery cell to be transferred to the battery case 1.

[0027] In contrast, in this embodiment, by setting the minor axis diameter L2 as described above, it is possible to minimize the expansion of the width (length in the major axis direction) of the slit 13 when a cylindrical battery cell is accommodated in the accommodation section 11. In other words, it is possible to increase the contact area between the wall section 12 and the surface of the cylindrical battery cell compared to the comparative example. This makes it easier to transfer heat generated from the cylindrical battery cell to the battery case 1, further improving the heat dissipation performance of the cylindrical battery cell.

[0028] -Second embodiment of the battery case of the present disclosure- A second embodiment of the battery case of the present disclosure will be described with reference to Figures 4 and 5. The second embodiment differs from the first embodiment described above in the position of the slit 13 provided in the wall portion 12. The other configurations are basically the same as those of the first embodiment described above. The different configurations will be described below.

[0029] In this embodiment, the slit 13 (13a) provided in the outermost storage section 11 (hereinafter referred to as the outermost storage section 11a) among the multiple storage sections 11 is arranged to overlap with the central axis C1 of the elliptical cylindrical space in the storage section 11a when viewed from the side of the battery pack 100.

[0030] By positioning the slits 13a of the outermost housing portion 11a in the above position, it is possible to suppress fluctuations in the position of the outermost housing portion 11a in the minor axis direction before and after housing the cylindrical battery cell in the outermost housing portion 11a.

[0031] In this embodiment, the slits 13 (13b, 13c) provided in the housing sections 11 (11b, 11c) located inside the outermost housing section 11a among the multiple housing sections 11 are provided at positions overlapping with the central axes C (C2, C3) of the elliptical cylindrical spaces of the housing sections 11 (11b, 11c) in a plan view of the battery case 1. In FIG. 5 showing an example, the slit 13b of the housing section 11b located at the center (hereinafter referred to as the central housing section 11b) is provided below the central housing section 11b (in the negative direction of the minor axis in FIG. 5). In contrast, the slit 13c of the housing section 11c between the central housing section 11b and the outermost housing section 11a (hereinafter referred to as the intermediate housing section 11c) is provided above the intermediate housing section 11c (in the positive direction of the minor axis in FIG. 5).

[0032] The effects of the above configuration will be explained with reference to Figure 5. First, when a cylindrical battery cell is placed in the central storage section 11b, the slit 13b expands. As a result, the intermediate storage section 11c and the outermost storage section 11a move in the positive direction of the minor axis in Figure 5. In other words, the storage sections 11a-11c of the battery case 1 are arranged in a V-shape when viewed from the direction of the central axes C1-C3 (not shown).

[0033] Subsequently, when a cylindrical battery cell is accommodated in the intermediate accommodation section 11c, the slits 13c expand, causing the outermost accommodation section 11a to move in the negative direction in the minor axis direction in Figure 5 (not shown).

[0034] Finally, even if cylindrical battery cells are accommodated in the outermost housing section 11a, as explained above, fluctuations in the position of the outermost housing section 11a (fluctuations in the minor axis direction in FIG. 5) are suppressed. Note that the order in which cylindrical battery cells are accommodated in the housing sections 11a is not limited to the above-mentioned order of central housing section 11b, intermediate housing section 11c, and outermost housing section 11a. For example, cylindrical battery cells may be accommodated in the outermost housing section 11a first, or cylindrical battery cells may be accommodated in the intermediate housing section 11b first.

[0035] These actions make it possible to suppress deformation of the battery case 1 before and after the cylindrical battery cells are housed (in other words, deformation of the battery case 1 as a whole in the up-and-down direction (short axis direction)).

[0036] Furthermore, in this embodiment, among the multiple storage sections 11, the storage sections 11b and 11c are located inside the outermost storage section 11a, and the slits 13 of the adjacent storage sections 11 are staggered when viewed from the front of the battery case 1. In this specification, "staggered" refers to the slit positions overlapping when the adjacent storage sections 11 are rotated 180° around the center of the storage sections 11. This configuration can distribute the stress on the cylindrical battery cells generated by the wall sections 12, allowing all the cylindrical battery cells to be more closely attached to the battery case 1. Furthermore, since the left and right battery cases 1 can be made to deform similarly around the central storage section 11b, deformation of the battery case 1 in the up-down direction (the minor axis direction in FIG. 5 ) can be suppressed.

[0037] 5, which shows an example of this embodiment, the slits 13c of the intermediate storage portions 11c are formed on the upper side (positive direction in the minor axis direction) and the slits 13b of the central storage portion 11b are formed on the lower side (negative direction in the minor axis direction), but this is not limiting. For example, the same effect can be achieved by forming the slits 13c of the intermediate storage portions 11c on the lower side (negative direction in the minor axis direction) and the slits 13b of the central storage portion 11b on the upper side (positive direction in the minor axis direction).

[0038] -Third embodiment of the battery case of the present disclosure- A third embodiment of the battery case of the present disclosure will be described with reference to Figures 6 and 7. The third embodiment differs from the first and second embodiments described above in that a connecting member is provided to connect the walls of the outermost housing sections. The other configurations are basically the same as those of the first and second embodiments described above. The different configurations will be described below.

[0039] Connection parts The connecting member 40 of this embodiment connects the wall portions 12 of the outermost housing portions 11 together. Providing the connecting member 40 can improve the strength of the battery case 1. Furthermore, by connecting the wall portions 12 of the outermost housing portions 11 together using the connecting member 40, deformation of the battery case 1 in the longitudinal direction can be reduced. In other words, deformation of the entire battery case 1 can be suppressed.

[0040] The material of the connecting member 40 is preferably the same resin material as that of the wall portion 12 described above, but a material different from that of the wall portion 12 may also be used.

[0041] The connection member 40 may also be provided with a control circuit for controlling the power of the cylindrical battery cells. In other words, the connection member 40 can also function as a member for mounting the control circuit. Therefore, by providing the connection member 40 as in this embodiment, the surface area can be effectively utilized.

[0042] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments, but should be defined based on the claims. The technical scope of the present disclosure also includes all modifications within the scope and meaning equivalent to the claims.

[0043] The battery case of the present disclosure includes the following aspects. <1> A battery case having a plurality of storage sections each accommodating a single cylindrical battery cell, the storage sections being arranged in a line in one direction, the housing portion has a wall portion that defines a space for housing the cylindrical battery cell; the wall portion defines an elliptical cylindrical space before the cylindrical battery cell is housed therein; The direction in which the storage sections are arranged in one direction is defined as the long axis direction of the elliptical cylindrical space, the direction perpendicular to the long axis direction is defined as the short axis direction, and the direction perpendicular to the long axis direction and the short axis direction and parallel to the central axis of the elliptical cylindrical space is defined as the depth direction, The battery case has a longest major axis diameter in the major axis direction of the elliptical cylindrical space in the storage portion that is equal to or greater than the diameter of the cylindrical battery cell. <2> <1> The battery case according to claim 1, The wall portion has a slit formed therein parallel to the central axis of the elliptical cylindrical space. <3> <1> or <2> The battery case according to claim 1, a battery case in which the slits formed in the plurality of storage sections are plane-symmetrical with respect to a bisecting plane of the battery case that is parallel to the longest minor axis diameter in the minor axis direction of the elliptical cylindrical space. <4> <2> or <3> The battery case according to claim 1, The slit is provided in a boundary region between the adjacent storage sections. <5> <1> ~ <4> The battery case according to any one of the above items, A battery case, wherein the slit formed in the central storage portion is positioned so as to overlap with the central axis of the elliptical cylindrical space in the storage portion when viewed from above. <6> <1> ~ <5> The battery case according to any one of the above items, A battery case, wherein a slit provided in the outermost storage section among the plurality of storage sections is provided at a position that overlaps with the central axis of the elliptical cylindrical space in the storage section when viewed from the side of the battery case. <7> <1> ~ <6> The battery case according to any one of the above items, A battery case, wherein a slit provided in a storage section located more inward than the outermost storage section among the plurality of storage sections is provided at a position that overlaps with the central axis of the elliptical cylindrical space in the storage section when viewed in a plane of the battery case. <8> <1> ~ <7> The battery case according to any one of the above items, In a battery case, in a storage section located more inward than an outermost storage section among the plurality of storage sections, the slits of adjacent storage sections are staggered when viewed from the front of the battery case. <9> <1> ~ <8> The battery case according to any one of the above items, A battery case having a connecting member that connects the walls of the outermost storage section. <10> <1> ~ <9> The battery case according to any one of the above items, The battery case, wherein the length of the storage section in the depth direction is equal to or greater than the length of the cylindrical battery cell stored therein in the depth direction. <11> <1> ~ <10> The battery case according to any one of the above items, The battery case has walls of adjacent storage sections connected to each other. <12> <1> ~ <11> The battery case according to any one of the above items, The battery case, wherein the longest minor axis diameter in the minor axis direction of the elliptical cylindrical space in the storage portion is a length that is 90% or more of the diameter of the cylindrical battery cell. [Industrial Applicability]

[0044] The present disclosure can be used for a battery case that can appropriately accommodate cylindrical battery cells. [Explanation of symbols]

[0045] 1 Battery case 11, 11a to 11c Storage section 12 Wall 13, 13a~13c Slit 40 Connecting member 100 battery packs A boundary area Ap Boundary position C1~C3 center axis L1 major axis diameter L2 short axis diameter P bisector

Claims

1. A battery case including a plurality of storage sections each accommodating a single cylindrical battery cell, the storage sections being arranged in a line in one direction, the housing portion has a wall portion that defines a space for housing the cylindrical battery cell; the wall portion defines an elliptical cylindrical space before the cylindrical battery cell is housed therein; The direction in which the storage sections are arranged in one direction is defined as the long axis direction of the elliptical cylindrical space, the direction perpendicular to the long axis direction is defined as the short axis direction, and the direction perpendicular to the long axis direction and the short axis direction and parallel to the central axis of the elliptical cylindrical space is defined as the depth direction, the longest major axis diameter in the major axis direction of the elliptical cylindrical space in the housing portion is equal to or greater than the diameter of the cylindrical battery cell; The wall portion has a slit formed therein parallel to the central axis of the elliptical cylindrical space.

2. The battery case according to claim 1, a battery case in which the slits formed in the plurality of storage sections are plane-symmetrical with respect to a bisecting plane of the battery case that is parallel to the longest minor axis diameter in the minor axis direction of the elliptical cylindrical space.

3. The battery case according to claim 1, The slit is provided in a boundary region between the adjacent storage sections.

4. The battery case according to claim 1, A battery case, wherein the slit formed in the central storage portion is positioned so as to overlap with the central axis of the elliptical cylindrical space in the storage portion when viewed from above.

5. The battery case according to claim 1, A battery case, wherein a slit provided in the outermost storage section among the plurality of storage sections is provided at a position that overlaps with the central axis of the elliptical cylindrical space in the storage section when viewed from the side of the battery case.

6. The battery case according to claim 1, A battery case, wherein a slit provided in a storage section located more inward than the outermost storage section among the plurality of storage sections is provided at a position that overlaps with the central axis of the elliptical cylindrical space in the storage section when viewed in a plane of the battery case.

7. The battery case according to claim 1, In a battery case, in a storage section located more inward than an outermost storage section among the plurality of storage sections, the slits of adjacent storage sections are staggered when viewed from the front of the battery case.

8. The battery case according to claim 1, A battery case having a connecting member that connects the walls of the outermost storage section.

9. The battery case according to claim 1, The battery case, wherein the length of the storage section in the depth direction is equal to or greater than the length of the cylindrical battery cell stored therein in the depth direction.

10. The battery case according to claim 1, The battery case has walls of adjacent storage sections connected to each other.

11. The battery case according to claim 1, The battery case, wherein the longest minor axis diameter in the minor axis direction of the elliptical cylindrical space in the storage portion is a length that is 90% or more of the diameter of the cylindrical battery cell.

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