Energy storage device

Abstract

The present invention provides an energy storage device that suppresses the movement of the energy storage element caused by the deformation of the separator when force is applied to the separator. [Solution] The energy storage device comprises an energy storage element and a separator 4 disposed between a first energy storage element and a second energy storage element adjacent to each other in the first direction X. The separator has a first member 41 and a second member 42 facing each other in the first direction, and an elastic body 43 disposed between the first member and the second member. The first member, the second member, and the elastic body are separate entities.

Description

Technical Field

[0001] The present invention relates to a power storage device including a plurality of power storage elements.

Background Art

[0002] Patent Document 1 discloses a power supply device 100 including a battery block 102 formed by laminating a plurality of battery cells 101 in the thickness direction with a separator 110 interposed therebetween (see FIG. 15).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=3报4]] In the above power supply device 100, the separator 110 disposed between adjacent battery cells 所101 has elastomer layers 111 on both sides, and a plurality of convex portions 112 are formed on the outer surface 111a of the elastomer layer 111. <报

[0005] When a force is applied to the separator 110 from the battery cell 101 or the like, the separator 110 is deformed (stretched, compressed, etc.). For example, in the power supply device 100, when a force is applied to the separator 110 when the battery block 102 is compressed in the thickness direction by a binding bar or when an impact is applied to the power supply device 100, the separator 110 is deformed.

[0006] [[ID=报2]] When the separator 110 is deformed in this way, the deformation direction of the convex portion 112 affects the position (arrangement position) of the battery cell 101 adjacent to the separator 110. Therefore, depending on the deformation direction of the convex portion 112, the position of the battery cell 101 changes, but it is difficult to control the deformation direction of the convex portion 112 when the separator 110 is deformed.

[0007] Therefore, the objective of this embodiment is to provide an energy storage device that suppresses the movement of the energy storage element caused by the deformation of the separator when force is applied to the separator. [Means for solving the problem]

[0008] The energy storage device of this embodiment is Energy storage element, The system comprises a separator positioned between a first energy storage element and a second energy storage element that are adjacent to each other in the first direction, The separator comprises a first member and a second member facing each other in the first direction, and an elastic body disposed between the first member and the second member. The first member, the second member, and the elastic body are separate entities. [Effects of the Invention]

[0009] Based on the above, this embodiment provides an energy storage device in which the movement of the energy storage element caused by the deformation of the separator when a force is applied to the separator is suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of the energy storage device according to this embodiment. [Figure 2] Figure 2 is an exploded perspective view of the laminated structure of the energy storage device. [Figure 3] Figure 3 is a view of the separator in the energy storage device in the X-axis direction. [Figure 4] Figure 4 is an enlarged cross-sectional view of the IV-IV position in Figure 3. [Figure 5] Figure 5 is an exploded perspective view of the separator. [Figure 6] Figure 6 is an exploded perspective view of the restraint portion of the energy storage device. [Figure 7] Figure 7 shows the cross-sectional state when the separator is not being compressed in the X-axis direction. [Figure 8]FIG. 8 is a diagram showing a cross-sectional state when the separator is compressed in the X-axis direction. [Figure 9] FIG. 9 is a cross-sectional view for showing the configuration of a separator according to another embodiment. [Figure 10] FIG. 10 is a diagram showing a flat spherical elastic body according to another embodiment. [Figure 11] FIG. 11 is a diagram showing a polyhedral elastic body according to another embodiment. [Figure 12] FIG. 12 is a perspective view for explaining a columnar elastic body according to another embodiment. [Figure 13] FIG. 13 is a diagram showing a cross-sectional state when a separator in which a first member and a convex portion are integrated is not compressed in the thickness direction. [Figure 14] FIG. 14 is a diagram showing a cross-sectional state when a separator in which a first member and a convex portion are integrated is compressed in the thickness direction. [Figure 15] FIG. 15 is a diagram for explaining the configuration of a separator in a conventional power storage device.

MODE FOR CARRYING OUT THE INVENTION

[0011] (1) A power storage device according to an embodiment of the present invention includes a power storage element, and a separator disposed between a first power storage element and a second power storage element adjacent to each other in a first direction among the power storage elements. The separator has a first member and a second member facing each other in the first direction, and an elastic body disposed between the first member and the second member. The first member, the second member, and the elastic body are separate bodies.

[0012] According to the power storage device according to an embodiment of the present invention, by using an elastic body that independently deforms together with two members (a first member and a second member) as a separator, when a force is applied to the separator, the elastic body independently deforms, so that the movement of the power storage element (the first power storage element or the second power storage element) caused by the deformation of the separator is suppressed.

[0013] (2) In the power storage device according to (1) above, the first member is in contact with the first power storage element, the second member may be in contact with the second power storage element.

[0014] According to the power storage device described in (2) above, only a separator is disposed between adjacent power storage elements (the first power storage element and the second power storage element), so that the distance between the adjacent power storage elements can be suppressed.

[0015] (3) In the power storage device according to (1) or (2) above, at least one of the first member and the second member may have a recess in which the elastic body is disposed at a position corresponding to the elastic body.

[0016] According to the power storage device described in (3) above, positioning of the elastic body with respect to at least one of the first member and the second member becomes easy.

[0017] (4) In the power storage device according to (3) above, only the first member of the first member and the second member may have the recess.

[0018] According to the power storage device described in (4) above, positioning of the elastic body with respect to the first member becomes easy.

[0019] (5) In the power storage device according to (3) or (4) above, when viewed from the first direction, the recess may be larger than a contact portion of the recess with the elastic body.

[0020] According to the power storage device described in (5) above, when a force is applied to the separator and the separator is deformed, the elastic body can easily move within the recess. As a result, movement of the power storage element due to deformation of the separator in the power storage element adjacent to the separator (the first power storage element or the second power storage element) is more preferably suppressed.

[0021] (6) In any one of the energy storage devices described in (1) to (5) above, The separator has a third member, The first member is positioned between the second member and the third member, and the elastic body is positioned between the first member and the third member, and between the second member and the third member, respectively. The third member and the elastic body may be separate entities.

[0022] According to the energy storage device described in (6) above, when a force is applied to the separator and the separator deforms, the elastic body placed between the first member and the second member, and the elastic body placed between the first member and the third member can move, so that movement caused by the deformation of the separator is more effectively suppressed in the energy storage element adjacent to the separator (first energy storage element or second energy storage element).

[0023] Hereinafter, one embodiment of the present invention will be described with reference to Figures 1 to 8. Note that the names of each component (each element) in this embodiment are those of this embodiment and may differ from the names of each component (each element) in the background art.

[0024] As shown in Figures 1 and 2, the energy storage device 1 according to this embodiment comprises a plurality of energy storage elements 3 arranged in a row, and a separator 4 positioned between two adjacent energy storage elements 3 in the direction of arrangement of the energy storage elements 3 (stacking direction, first direction). Further details are as follows.

[0025] The energy storage device 1 comprises a laminate 2 on which energy storage elements 3 are stacked, and a restraining part 5 that restrains the laminate 2. The energy storage device 1 also has a plurality of busbars 6 that electrically connect (connect) the energy storage elements 3 to each other.

[0026] The laminate 2 has a plurality of energy storage elements 3 and a plurality of separators 4. In this laminate 2, the energy storage elements 3 and separators 4 are arranged alternately in the stacking direction.

[0027] Each of the multiple energy storage elements 3 is a primary battery, a secondary battery, a capacitor, etc. The energy storage element 3 in this embodiment is a rechargeable non-aqueous electrolyte secondary battery. More specifically, the energy storage element 3 is a lithium-ion secondary battery that utilizes electron transfer that occurs with the movement of lithium ions.

[0028] Specifically, each energy storage element 3 comprises an electrode body, a case 31 that houses the electrode body together with an electrolyte, terminals 34 that at least a portion of which are exposed to the outside of the case 31, and a current collector that connects (makes conductive) the electrode body and the terminals 34.

[0029] In the electrode body, positive and negative electrodes are stacked alternately with a separator in between. In this electrode body, lithium ions move between the positive and negative electrodes, causing the energy storage element 3 to charge and discharge.

[0030] Case 31 has a case body 32 having an opening and a plate-shaped cover portion 33 that closes the opening of the case body 32. In this embodiment, the case body 32 is a bottomed rectangular tube, and the case 31 is a rectangular parallelepiped (hexagonal) shape. In this embodiment, the case 31 is a flat rectangular parallelepiped shape, and the multiple energy storage elements 3 are arranged in a line in the laminate 2 with the wide surfaces (walls) of the case 31 (case body 32) facing each other via separators 4.

[0031] In the following explanation, the stacking direction (first direction) of the multiple energy storage elements 3 is defined as the X-axis direction in the Cartesian coordinate system, the normal direction of the cover portion 33 is defined as the Z-axis direction in the Cartesian coordinate system, and the directions perpendicular to the X-axis direction and the Z-axis direction are defined as the Y-axis direction in the Cartesian coordinate system.

[0032] Each of the multiple separators 4 is insulating and is placed between energy storage elements 3 aligned in the X-axis direction, or between an energy storage element 3 and a member aligned in the X-axis direction relative to the energy storage element 3 (in this embodiment, a part of the restraining portion 5 (end member) 51).

[0033] As shown in Figures 3 to 5, each separator 4 has a shape corresponding to the energy storage element 3 when viewed from the X-axis direction (in this embodiment, it is a rectangular shape that is elongated in the Y-axis direction). Specifically, the separator 4 has a sheet-like first member 41 and a sheet-like second member 42 facing each other in the X-axis direction, and an elastic body 43 positioned between the first member 41 and the second member 42. In this embodiment, "sheet-like" means a shape that extends in a plane direction perpendicular to the X-axis direction (extending along a plane that includes the Y-axis and Z-axis directions).

[0034] In this separator 4, the first member 41, the second member 42, and the elastic body 43 are separate components. The separator 4 of this embodiment has multiple elastic bodies 43. In this embodiment, "separate component" means a state in which they can be separated. That is, in the separator 4 of this embodiment, the first member 41, the second member 42, and the elastic body 43 are each separable.

[0035] The first member 41 is a member that contacts (specifically, makes surface contact with) the first energy storage element 3A when the separator 4 is positioned between two adjacent energy storage elements 3 in the X-axis direction (first energy storage element 3A and second energy storage element 3B: see Figure 2). This first member 41 is a sheet-like member and has a rectangular shape that is elongated in the Y-axis direction when viewed from the X-axis direction. In other words, the sheet-like first member 41 is shaped like a plate that can be sandwiched between the energy storage elements 3. The first member 41 may have protrusions or recesses formed on it as long as it is shaped to be sandwiched between the energy storage elements 3.

[0036] The first member 41 of this embodiment has a recess 411 in which the elastic body 43 is positioned at a location corresponding to the elastic body 43. The first member 41 of this embodiment has a plurality of recesses 411 (a number corresponding to the elastic body 43). The first member 41 of this embodiment is formed of a resin (for example, mica, silicone, elastomer, foamed rubber (filler), rubber) and has thermal insulation properties, but is not limited to this. The material of the first member 41 can be any material that does not hinder the deformation of the elastic body 43. Because the first member 41 has thermal insulation properties and recesses 411, it is possible to achieve thermal insulation and suppress the movement of the energy storage element 3 with a single member, thereby reducing the number of parts. Having thermal insulation properties here means that the thermal conductivity is 0.01 w / m·k or more and 0.18 w / m·k or less. For example, the thermal conductivity of the first member should be lower than that of other structural members. The thermal conductivity in this invention is measured according to JIAA1412-1:2016.

[0037] The multiple recesses 411 are all the same shape and are circularly recessed when viewed from the X-axis direction. Specifically, each recess 411 has a circular recess bottom surface 412 that extends in a plane direction perpendicular to the X-axis direction, and an inner recess surface 413 that extends from the periphery of the recess bottom surface 412 in the X-axis direction (see Figure 4). Here, the recesses 411 do not have to be circular. The shape of the recesses 411 may be changed to match the elastic body 43. For example, the recesses 411 may be polygonal, such as a square. Not all of the multiple recesses 411 have to be the same shape.

[0038] In the first member 41, multiple rows of recesses 411A, each having a gap in the Y-axis direction, are arranged at intervals in the Z-axis direction (see Figure 5). In adjacent rows of recesses 411A in the Z-axis direction, the recesses 411 are arranged so that their positions in the Y-axis direction are staggered. This allows the elastic bodies 43, which are arranged to correspond to each evenly distributed recess 411 in the first member 41, to move individually, so that the elastic bodies 43 can more efficiently receive external forces (such as compression), and the movement of the energy storage element 3 is more efficiently suppressed. Herein, the arrangement of each recess 411 in the first member 41 is not limited to this embodiment. For example, the rows of recesses 411A may be arranged without gaps, and in adjacent rows of recesses 411A in the Z-axis direction, the positions of the recesses 411 in the Y-axis direction do not have to be staggered. The recess 411 may be located only in the center of the long side of the first member 41, or it may be located so as to surround the inner circumference of the long side of the first member 41 (avoiding the center), or it may be located only at the corner of the first member 41. In any case, the elastic body 43 is located to correspond to the recess 411, and movement of the energy storage element due to deformation of the separator 4 is suppressed.

[0039] The second member 42 is a member that contacts (specifically, makes surface contact with) the second energy storage element 3B when the separator 4 is positioned between two adjacent energy storage elements 3 in the X-axis direction (between the first energy storage element 3A and the second energy storage element 3B). This second member 42 is a sheet-like member and has a rectangular shape that is elongated in the Y-axis direction when viewed from the X-axis direction. In other words, the sheet-like second member 42 is shaped like a plate that can be sandwiched between the energy storage elements 3. The second member 42 may have protrusions or recesses formed on it as long as it is shaped to be sandwiched between the energy storage elements 3.

[0040] The second member 42 in this embodiment is formed of a resin or the like (for example, mica, elastomer, foamed rubber, silica-based insulation material, ceramic fiber-based insulation material, vacuum insulation material, etc.) and has thermal insulation properties, but the material of the second member 42 does not need to be a material that hinders the deformation of the elastic body 43. Because the second member 42 has thermal insulation properties and a recess 411, it is possible to achieve thermal insulation and suppress the movement of the energy storage element 3 with a single member, thus reducing the number of parts. The dimension of the second member 42 in the X-axis direction in this embodiment is larger than the dimension of the first member 41 in the X-axis direction. That is, the second member 42 is thicker than the first member 41. The relative thicknesses of the second member 42, the first member 41, and the first member 41 and second member 42 are set based on the thermal conductivity of the first member 41 and the thermal conductivity of the second member 42.

[0041] Each of the multiple elastic bodies 43 is positioned between the first member 41 and the second member 42, corresponding to a recess 411 in the first member 41. Each elastic body 43 has the same shape (spherical in this embodiment) and is made of an elastomer, rubber, polymer, resin, or the like.

[0042] The diameter D1 of the elastic body 43 is smaller than the diameter D2 of the recess 411 (see Figure 4). In this embodiment, the diameter D1 of the elastic body 43 and the diameter D2 and depth of the recess 411 are set so that the elastic body 43 fits within the recess 411 when it deforms due to impact or assumed load. For example, the diameter D1 of the elastic body 43 and the diameter D2 and depth of the recess 411 may be set according to the Poisson's ratio of the elastic body 43. Also, for example, when the laminate 2 is restrained (tightened in the X-axis direction) by the restraining part 5, the elastic body 43 is compressed so that its dimension in the X-axis direction becomes smaller (see Figure 8). In this compressed state, the contact portion α between the elastic body 43 and the bottom surface 412 of the recess 411 (see Figure 8) is smaller than the diameter of the recess 411.

[0043] As shown in Figures 1 and 6, the restraining part 5 surrounds the laminate 2, thereby restraining the laminate 2 in a tightly fastened state in the X-axis direction. Specifically, the restraining part 5 includes a pair of end members 51 positioned on both sides of the laminate 2 (a plurality of energy storage elements 3 arranged in the X-axis direction), a pair of side members 52 connecting the pair of end members 51, and a plurality of connecting members 53 connecting the end members 51 and the side members 52.

[0044] The pair of end members 51 are positioned on both sides of the laminate 2 in the X-axis direction. Specifically, each of the pair of end members 51 is positioned to sandwich the separator 4 between itself and the energy storage element 3, which is located at the X-axis end (outermost part) of the laminate 2. Each of these pair of end members 51 is a rectangular plate-like shape, corresponding in size to the energy storage element 3 when viewed from the X-axis direction. Specifically, each end member 51 is a rectangular shape that is elongated in the Y-axis direction, and each has a connecting recess 511 at both ends in the Y-axis direction that is recessed inward in the Y-axis direction. In addition, each end member 51 has a plurality of first through holes 512 at both ends in the Y-axis direction, spaced apart in the Z-axis direction.

[0045] The pair of side members 52 are positioned on both sides of the laminate 2 in the Y-axis direction and extend along the laminate 2 in the X-axis direction. Each of these pair of side members 52 is a rectangular shape with a size corresponding to the laminate 2 when viewed from the Y-axis direction. Specifically, each side member 52 has a rectangular side member body 521 that is elongated in the X-axis direction, and a pair of connecting protrusions 522 that extend from both ends of the side member body 521 in the X-axis direction toward the inside in the Y-axis direction (towards the center of the laminate 2).

[0046] Each connecting projection 522 fits into the corresponding connecting recess 511 of the end member 51. Each of these connecting projections 522 has a plurality of second through holes 523 that are spaced apart in the Z-axis direction. Each second through hole 523 overlaps with the corresponding first through hole 512 of the end member 51 when viewed from the X-axis direction.

[0047] Each of the multiple connecting members 53 connects the end member 51 and the side member 52 by inserting it through the first through hole 512 of the end member 51 and the second through hole 523 of the side member 52 (connecting projection 522).

[0048] Each of the multiple busbars 6 is a conductive plate-shaped member made of metal or the like, as shown in Figures 1 and 2. Each busbar 6 connects the terminals 34 of the energy storage elements 3 to each other. The multiple busbars 6 in this embodiment connect (connect) the multiple energy storage elements 3 included in the energy storage device 1 in series.

[0049] The energy storage device 1 described above comprises a plurality of energy storage elements 3, and a separator 4 positioned between two adjacent energy storage elements 3 (a first energy storage element 3A and a second energy storage element 3B) in the X-axis direction (first direction). The separator 4 has a first member 41 and a second member 42 facing each other in the X-axis direction, and an elastic body 43 positioned between the first member 41 and the second member 42, with the first member 41, the second member 42 and the elastic body 43 being separate components.

[0050] In this way, by using the independently deformable elastic body 43 together with two members (first member 41 and second member 42) as a separator 4, when a force is applied to the separator 4, the elastic body 43 deforms independently, thereby suppressing the movement of the energy storage element (first energy storage element 3A or second energy storage element 3B) caused by the deformation of the separator 4.

[0051] For example, when assembling the energy storage device 1, if the laminated body 2 is not restrained (tightened in the X-axis direction) by the restraining part 5, as shown in Figure 7, each elastic body 43 positioned between the first member 41 and the second member 42 in the separator 4 arranged between each energy storage element 3 is not crushed (i.e., the elastic body 43 is spherical).

[0052] From this state, the laminate 2 is restrained by the restraining part 5, and a force is applied to each separator 4 from the adjacent energy storage elements 3 (first energy storage element 3A and second energy storage element 3B) in the direction of being squeezed in the X-axis direction (compressed in the X-axis direction: see arrow in Figure 7), causing each elastic body 43 of the separator 4 to collapse in the X-axis direction, as shown in Figure 8. At this time, since each elastic body 43 is separate from the first member 41 and the second member 42, it can move in a plane direction perpendicular to the X-axis direction relative to the first member 41 and the second member 42, thereby suppressing the relative movement of the first member 41B and the second member 42B in the aforementioned orthogonal plane direction (i.e., relative movement of the first energy storage element 3A and the second energy storage element 3B in the aforementioned orthogonal plane direction: relative movement in the vertical direction in the example shown in Figure 14) that results from the collapse of the separator 4B (i.e., the separator in which the first member 41B is integrated with the convex part 415B) 4B in the X-axis direction.

[0053] In other words, as shown in Figures 13 and 14, if the separator 4B deforms and the energy storage element adjacent to the separator 4B moves (in other words, the energy storage elements adjacent to each other with the separator 4B in between move relatively), then variations in the position of the energy storage elements in the laminate 2 can occur. For example, variations in the position of the terminals of the energy storage elements can occur, making it difficult to attach other members such as busbar plates that hold busbars to the laminate 2. However, in the energy storage device 1 of this embodiment, since the elastic body 43 in the separator 4 is independent of the members that sandwich the elastic body 43 (first member 41 and second member 42), the movement of the energy storage element (first energy storage element 3A or second energy storage element 3B) caused by the deformation of the separator 4 when force is applied to the separator 4 is suppressed. Therefore, relative movement of the two energy storage elements 3A and 3B with the separator 4 in between is suppressed, thereby reducing variations in the position of the energy storage elements 3 in the laminate 2, and as a result, it becomes easier to attach other components to the laminate 2.

[0054] Furthermore, even when force is applied to the separator 4 due to an external impact on the energy storage device 1, the elastic body 34 being separate from the first member 41 and the second member 42 suppresses the movement of the energy storage elements 3 (the first energy storage element 3A or the second energy storage element 3B adjacent to the separator 4) caused by the deformation of the separator 4 when force is applied to the separator 4. This suppresses variations in the position of the energy storage elements 3 in the laminate 2 due to the aforementioned impact.

[0055] In the above, examples of causes of force being applied to the separator 4 include the restraint of the laminated body 2 by the restraint part 5 and external impacts to the energy storage device 1, but are not limited to these. According to the separator 4 of this embodiment, even if the separator 4 is deformed due to force applied by other factors, the movement of the energy storage elements 3 (energy storage elements 3 adjacent to the separator 4) caused by the deformation is suppressed.

[0056] Furthermore, in the energy storage device 1 of this embodiment, the first member 41 is in contact with the first energy storage element 3A (i.e., one of the two adjacent energy storage elements 3), and the second member 42 is in contact with the second energy storage element 3B (i.e., the other of the two adjacent energy storage elements 3). In this way, by placing only a separator 4 between the two adjacent energy storage elements 3 (between the first energy storage element 3A and the second energy storage element 3B), the distance between the adjacent energy storage elements 3 is reduced.

[0057] Furthermore, in the energy storage device 1 of this embodiment, only the first member 41 of the two members 42 (the first member 41 and the second member 42) has the recess 411. This makes it easier to position the elastic body 43 relative to the first member 41.

[0058] Furthermore, in the energy storage device 1 of this embodiment, when viewed from the X-axis direction (first direction), the diameter D2 of the recess 411 is larger than the contact portion α with the elastic body 43 in the recess 411 (more specifically, the bottom surface 412 of the recess) (see Figure 8). Therefore, when a force is applied to the separator 4 and the separator 4 deforms, the elastic body 43 can move easily within the recess 411 (in other words, it has a wide range of movement). As a result, movement caused by the deformation of the separator 4 in the energy storage element 3 (first energy storage element 3A or second energy storage element 3B) adjacent to the separator 4 is more effectively suppressed.

[0059] It should be noted that the energy storage device of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Furthermore, a part of the configuration of one embodiment can be deleted.

[0060] The separator 4 in the above embodiment has two sheet-like members (first member 41, second member 42), but is not limited to this configuration. As shown in Figure 9, the separator 4A may further have a third member 45, and the first member 41 may be positioned between the second member 42 and the third member 45. These first member 41, second member 42, and third member 45 each extend in a planar direction perpendicular to the X-axis direction (a planar direction including the Y-axis and Z-axis directions) and face each other in the X-axis direction. In this case, the elastic body 43 is positioned between the second member 42 and the first member 41, and between the third member 45 and the first member 41, and the first member 41 and the elastic body 43 are separate entities. Also, the second member 42, the third member 45, and the elastic body 43 are separate entities. In the example shown in Figure 9, the first member 41 has recesses 411 on both sides.

[0061] With this configuration, when a force is applied to the separator 4A and the separator 4A deforms, the elastic bodies 43 can move on both sides of the first member 41 in the X-axis direction. As a result, the movement of the energy storage element 3 (first energy storage element 3A or second energy storage element 3B) adjacent to the separator 4A due to the deformation of the separator 4A is more effectively suppressed. In other words, relative movement due to the deformation of the separator 4A is more effectively suppressed between the first energy storage element 3A and the second energy storage element 3B, which are sandwiched between the separator 4A.

[0062] Furthermore, in the separator 4 of the above embodiment, the elastic body 43 positioned between the first member 41 and the second member 42 is spherical, but is not limited to this configuration. The elastic body 43 may be a flattened sphere (see Figure 10), or a substantially spherical shape with a surface composed of many planes (see Figure 11), etc. In other words, the elastic body 43 only needs to be shaped to be movable relative to the first member 41 and the second member 42 when a force is applied to the separator 4.

[0063] Furthermore, the elastic body 43 may be cylindrical or the like, as shown in Figure 12. This configuration also suppresses the relative movement of the first energy storage element 3A and the second energy storage element 3B in at least one direction (the direction in which the cylindrical elastic body 43 can roll: in the example shown in Figure 12, the Z-axis direction) when a force is applied to the separator 4.

[0064] Furthermore, in the separator 4 of the above embodiment, the first member 41 of the first member 41 and the second member 42 has a recess 411, but the configuration is not limited to this. For example, the second member 42 may have a recess 411, or the first member 41 and the second member 42 may each have a recess 411. That is, it is sufficient that at least one of the first member 41 and the second member 42 has a recess 411 in which the elastic body 43 is positioned at a location corresponding to the elastic body 43.

[0065] With this configuration, the positioning of the elastic body 43 with respect to at least one of the members (first member 41 or second member 42) becomes easier.

[0066] Furthermore, the arrangement pattern of the recesses 411 in the first member 41, etc., is not limited. Also, neither the first member 41 nor the second member 42 has recesses 411. For example, as shown in Figure 12, even if neither the first member 41 nor the second member 42 has recesses 411, it is sufficient that the elastic body 43 can be held. In this case, from the viewpoint of facilitating the positioning of the elastic body 43, grooves may be formed in at least one of the first member 41 and the second member 42, or the elastic body 43 may be attached with an adhesive or the like.

[0067] In the above embodiment, the energy storage device 1 has restraining parts 5 such as an end member 51 and a side member 52, but it is not necessary to have restraining parts 5. Even in this case, if the energy storage device 1 is subjected to an external impact, the movement of the energy storage element 3 adjacent to the separator 4 due to deformation of the separator 4 will be suppressed.

[0068] Furthermore, in the separator 4 of the above embodiment, the contact area α (see Figure 8) between the elastic body 43 and the recess 411 (specifically, the bottom surface 412 of the recess) is smaller than the recess 411 when viewed from the X-axis direction, but the configuration is not limited to this. The contact area α between the elastic body 43 and the recess 411 may be the same as or larger than the recess 411 when viewed from the X-axis direction. [Industrial applicability]

[0069] This invention can be applied to energy storage elements such as lithium-ion secondary batteries. [Explanation of Symbols]

[0070] 1...Energy storage device, 2...Laminate, 3...Energy storage element, 3A...First energy storage element (energy storage element), 3B...Second energy storage element (energy storage element), 31...Case, 32...Case body, 33...Cover part, 34...Terminal, 4, 4A, 4B...Separator, 41, 41B...First component, 411...Recess, 411A...Row of recesses, 412...Bottom surface of recess, 413...Inner surface of recess, 415B...Protrusion, 42, 42B...Second component, 43...Elastic body, 45...Third Member, 5... restraining part, 51... end member, 511... connecting recess, 512... first through hole, 52... side member, 521... side member body, 522... connecting protrusion, 523... second through hole, 53... connecting member, 6... busbar, 100... power supply unit, 101... battery cell, 102... battery block, 110... separator, 111... elastomer layer, 111a... outer surface, 112... protrusion, D1... diameter of elastic body, D2... inner diameter of recess

Claims

1. Energy storage element, The system comprises a separator positioned between a first energy storage element and a second energy storage element that are adjacent to each other in the first direction, The separator comprises a first member and a second member facing each other in the first direction, and an elastic body disposed between the first member and the second member. An energy storage device in which the first member, the second member, and the elastic body are separate entities.

2. The first member is in contact with the first energy storage element, The energy storage device according to claim 1, wherein the second member is in contact with the second energy storage element.

3. The energy storage device according to claim 1 or 2, wherein at least one of the first member and the second member has a recess in which the elastic body is disposed at a position corresponding to the elastic body.

4. The energy storage device according to claim 3, wherein only the first member among the first member and the second member has the recess.

5. The energy storage device according to claim 3, wherein, when viewed from the first direction, the recess is larger than the contact portion with the elastic body in the recess.

6. The separator has a third member, The first member is positioned between the second member and the third member. The elastic body is positioned between the first member and the third member, and between the second member and the third member, The energy storage device according to claim 1, wherein the third member and the elastic body are separate entities.

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