Power storage device

Abstract

To provide a power storage device having high rigidity to input of loads from above and can be easily disassembled.SOLUTION: A power storage device 10 can be loaded on a vehicle 1 and comprises a plurality of cells 100, buffer parts 200 and an upper plate part 310. The plurality of cells 100 are arranged in a first direction D1 along a horizontal direction. The buffer parts 200 are jointed to respective upper parts 101 of the plurality of cells 100. The buffer parts 200 extend in the first direction D1. The upper plate part 310 is arranged above the buffer parts 200. The upper plate part 310 is jointed to the buffer parts 200. The buffer parts 200 are configured to be separated in a vertical direction Z when tensile stress in a vertical direction Z occurs. The buffer parts 200 have starting points 201. The starting points 201 are starting points for the buffer parts 200 to separate, at edges 202 in the first direction D1.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2020-142589 (Patent Document 1) discloses that a battery pack is disposed below a floor panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-142589 Summary of the Invention [Problem to be solved by the invention]

[0004] Structures of electric storage devices that can increase the energy density of electric storage devices mounted on vehicles have been studied. For example, studies have been conducted to position the electric storage device below the floor panel as close to the floor panel as possible, or to have the electric storage device itself form part of the floor panel. However, if the electric storage device is designed in this manner, there is a possibility that a load from above the electric storage device may be input due to a load from inside the vehicle compartment, i.e., from above. Furthermore, if the electric storage device is designed to have a structure that increases the rigidity against the input of such a load, it may be difficult to disassemble the electric storage device from above during maintenance.

[0005] The present disclosure has been made in consideration of the above problems, and has an object to provide an electricity storage device that has high rigidity against input of a load from above and is easy to disassemble. [Means for solving the problem]

[0006] An electric storage device according to an aspect of the present disclosure can be mounted on a vehicle. The electric storage device includes a plurality of cells, a buffer portion, and an upper plate portion. The plurality of cells are aligned in a first direction along the horizontal direction. The buffer portion is joined to the upper portions of each of the plurality of cells. The buffer portion extends in the first direction. The upper plate portion is disposed above the buffer portion. The upper plate portion is joined to the buffer portion. The buffer portion is configured to be separable in the vertical direction when tensile stress is generated in the vertical direction. The buffer portion has a starting point portion. The starting point portion is an edge in the first direction that serves as a starting point for separation of the buffer portion.

[0007] In the power storage device according to an aspect of the present disclosure, the buffer portion preferably has, as a starting point portion, an opening portion facing the first direction.

[0008] In the power storage device according to an aspect of the present disclosure, the buffer section preferably has a plurality of voids aligned in the first direction.

[0009] In the power storage device according to an aspect of the present disclosure, the buffer portion preferably has, as a starting point, a notch portion extending inward from the end edge.

[0010] In an energy storage device according to an aspect of the present disclosure, the buffer portion preferably includes a lower buffer portion and an upper buffer portion. The lower buffer portion is located below the notch. The upper buffer portion is located above the notch. The upper buffer portion has an engagement portion. The engagement portion engages with the lower buffer portion such that the engagement with the lower buffer portion is released when the upper buffer portion is pulled upward.

[0011] In an energy storage device according to an aspect of the present disclosure, the buffer section preferably includes a plate-shaped main body section and an adhesive layer. The main body section extends in a first direction. The adhesive layer bonds the main body section and the upper plate section to each other. The adhesive layer includes a strong adhesive section and a weak adhesive section. The weak adhesive section serves as a starting point and bonds the main body section and the upper plate section to each other with a bonding strength weaker than that of the strong adhesive section. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide an electricity storage device that has high rigidity against input of a load from above and is easy to disassemble. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a vehicle equipped with a power storage device according to a first embodiment of the present disclosure. [Figure 2] 1 is a schematic perspective view showing a vehicle body of a vehicle equipped with a power storage device according to a first embodiment of the present disclosure. [Figure 3] 3 is a schematic cross-sectional view of a part of the vehicle of FIG. 1, as viewed from the direction of the arrows along line III-III. [Figure 4] 1 is a plan view showing an electricity storage device according to a first embodiment of the present disclosure together with a cross member of a vehicle body. [Figure 5] 1 is an exploded perspective view showing an electricity storage device according to a first embodiment of the present disclosure. [Figure 6] 6 is a cross-sectional view of the electricity storage device of FIG. 4, seen from the direction of the arrows along line VI-VI. [Figure 7] FIG. 2 is a schematic cross-sectional view of the electricity storage module. [Figure 8] 8 is a schematic cross-sectional view of the electricity storage device of FIG. 4, as viewed from the direction of the arrows along line VIII-VIII. [Figure 9] 4 is a partial cross-sectional view showing the electricity storage device in a state in which a vertical tensile stress is applied to a buffer section in the first embodiment. FIG. [Figure 10] 10 is a partial cross-sectional view showing the electricity storage device in a state where a tensile stress in the vertical direction is further generated in the buffer section, following the state shown in FIG. 9. FIG. [Figure 11] FIG. 6 is a partial cross-sectional view of an electricity storage device according to a second embodiment of the present disclosure. [Figure 12] 10 is a partial cross-sectional view showing the electricity storage device in a state in which a vertical tensile stress is applied to the buffer section in the second embodiment. FIG. [Figure 13] FIG. 10 is a partial cross-sectional view of an electricity storage device according to a third embodiment of the present disclosure. [Figure 14]11 is a partial cross-sectional view showing the electricity storage device in a state in which a vertical tensile stress is applied to the buffer section in the third embodiment. FIG. [Figure 15] 15 is a partial cross-sectional view showing the electricity storage device in a state where a vertical tensile stress is further generated in the buffer section, following the state shown in FIG. 14. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a power storage device according to each embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and description thereof will not be repeated.

[0015] (Embodiment 1) Fig. 1 is a schematic diagram showing a vehicle equipped with a power storage device according to a first embodiment of the present disclosure. As shown in Fig. 1, a power storage device 10 according to the first embodiment of the present disclosure is an power storage device that can be mounted on a vehicle 1. First, the vehicle 1 will be described.

[0016] The vehicle 1 according to the first embodiment is, for example, an electric vehicle such as an electric vehicle or a hybrid vehicle that can be driven by a motor. Fig. 2 is a schematic perspective view showing a vehicle body of a vehicle equipped with a power storage device according to the first embodiment of the present disclosure. Fig. 3 is a schematic cross-sectional view of a part of the vehicle in Fig. 1 as viewed from the direction of the arrows along line III-III. As shown in Figs. 1 to 3, the vehicle 1 according to the first embodiment of the present disclosure includes a power storage device 10 and a vehicle body 2 to which the power storage device 10 is fixed. The fore-and-aft direction of the vehicle 1 or the vehicle body 2 is parallel to a first direction D1, described below, of the power storage device 10.

[0017] The vehicle body 2 includes, as framework members of the vehicle 1, a plurality of cross members 3, a left side sill 4a, a right side sill 4b, a left side member 5a, and a right side member 5b.

[0018] Each of the multiple cross members 3 extends in the left-right direction of the vehicle body 2. The left-right direction or vehicle width direction of the vehicle 1 or the vehicle body 2 is parallel to a second direction D2 (described later) of the electricity storage device 10. The multiple cross members 3 are aligned with one another in the first direction D1. The vehicle body 2 may include only a single cross member 3.

[0019] The left side sill 4a is disposed on the left side in the left-right direction of the vehicle 1. The left side sill 4a extends in the front-rear direction of the vehicle 1. The right side sill 4b is disposed on the right side in the left-right direction of the vehicle 1. The right side sill 4b extends in the front-rear direction of the vehicle 1. Each of the multiple cross members 3 extends from the inside of the left side sill 4a to the inside of the right side sill 4b.

[0020] The left side member 5a is disposed on the left side in the left-right direction of the vehicle 1. The left side member 5a extends in the front-rear direction of the vehicle. The left side member 5a is disposed closer to the center of the vehicle in the vehicle width direction than the left side sill 4a. The right side member 5b is disposed on the right side in the left-right direction of the vehicle 1. The right side member 5b is disposed closer to the center of the vehicle in the vehicle width direction than the right side sill 4b.

[0021] Next, details of the power storage device 10 according to the first embodiment of the present disclosure will be described. Fig. 4 is a plan view showing the power storage device according to the first embodiment of the present disclosure together with a cross member of a vehicle body.

[0022] 3 and 4, the power storage device 10 includes a plurality of power storage modules 50. The plurality of power storage modules 50 are disposed below the cross member 3.

[0023] Each of the multiple energy storage modules 50 extends in a first direction D1. The first direction D1 is a direction along the horizontal direction. When viewed from the vertical direction Z, each of the multiple energy storage modules 50 is arranged so as to intersect with at least one cross member 3. When viewed from the vertical direction Z, each of the multiple energy storage modules 50 is arranged so as to intersect with multiple cross members 3. The multiple energy storage modules 50 are lined up in a second direction D2. The second direction D2 is a direction along the horizontal direction. The second direction D2 is a direction perpendicular to the first direction D1. In this embodiment, the multiple energy storage modules 50 are lined up only in the second direction D2.

[0024] The energy storage device 10 is required to include at least one energy storage module 50. The energy storage device 10 may include only one energy storage module 50. The multiple energy storage modules 50 may be arranged side by side in the first direction D1. The multiple energy storage modules 50 may be arranged side by side in the first direction D1 and also in the second direction D2. The multiple energy storage modules 50 may be arranged side by side only in the first direction D1.

[0025] Next, details of the energy storage module 50 will be described. Fig. 5 is an exploded perspective view showing the energy storage device according to the first embodiment of the present disclosure. Fig. 6 is a cross-sectional view of the energy storage device of Fig. 4 as seen from the direction of the arrows along line VI-VI. Fig. 7 is a schematic cross-sectional view of the energy storage module. Fig. 7 shows the same cross-sectional view as Fig. 6. Fig. 8 is a schematic cross-sectional view of the energy storage device of Fig. 4 as seen from the direction of the arrows along line VIII-VIII.

[0026] As shown in FIGS. 5 to 8, each of the plurality of power storage modules 50 includes a plurality of cells 100 and a buffer section 200.

[0027] Each of the plurality of cells 100 is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery, etc. The plurality of cells 100 are arranged in a first direction D1 that is aligned horizontally.

[0028] Each of the plurality of cells 100 has an upper portion 101 facing upward. Each of the plurality of cells 100 further has a first end surface portion 102, a second end surface portion 103, a bottom surface portion 104, a first side surface portion 105, and a second side surface portion 106.

[0029] The first end surface portion 102 extends downward from one edge of the upper portion 101 in the first direction D1. The second end surface portion 103 extends downward from the other edge of the upper portion 101 in the first direction D1. The bottom surface portion 104 is located on the opposite side of the upper portion 101. The bottom surface portion 104 is connected to the first end surface portion 102 and the second end surface portion 103.

[0030] The first side surface portion 105 faces one side of the second direction D2. The second side surface portion 106 faces the other side of the second direction. The first side surface portion 105 and the second side surface portion 106 are connected to the top portion 101, the first end surface portion 102, the second end surface portion 103, and the bottom surface portion 104.

[0031] Each of the multiple cells 100 includes an electrode assembly 110 and a cell case 120. The electrode assembly 110 includes a positive electrode layer, a negative electrode layer, and a separator (none of which are shown). The separator is interposed between the positive electrode layer and the negative electrode layer. The positive electrode layer and the negative electrode layer may be stacked in a first direction D1 with the separator interposed therebetween. The positive electrode layer and the negative electrode layer may be wound around the axial direction of a second direction D2 with the separator interposed therebetween.

[0032] The cell case 120 houses the electrode assembly 110. The cell case 120 may be made of a metal such as aluminum or an aluminum alloy. The cell case 120 forms at least a portion of each of the top portion 101, the first end surface portion 102, the second end surface portion 103, and the bottom surface portion 104. The cell case 120 has a so-called rectangular shape.

[0033] The buffer portion 200 extends in the first direction D1. When viewed from the vertical direction Z, the buffer portion 200 intersects with the multiple cross members 3. The buffer portion 200 is joined to the upper portion 101 of each of the multiple cells 100.

[0034] The buffer section 200 has a starting point 201, an edge 202, and multiple voids 203A. The starting point 201 will be described later. The edge 202 is located at one end of the buffer section 200 in the first direction D1. The multiple voids 203A are aligned in the first direction D1. The multiple voids 203A may be connected to each other or may be independent of each other. Each of the multiple voids 203A may extend in the second direction D2.

[0035] The buffer section 200 includes a main body section 210, a first adhesive layer 220, and a second adhesive layer 230. The main body section 210 is provided so as to cover the multiple cells 100. The main body section 210 has a generally plate-like outer shape. The main body section 210 extends in a first direction D1. An example of the main body section 210 is a surface pressure distribution board. In this embodiment, the starting point section 201, the edge 202, and the multiple void sections 203A are formed in the main body section 210. The material constituting the main body section 210 will be described later.

[0036] A plurality of grooves 215 may be formed on the lower surface of the main body 210. The plurality of grooves 215 may be provided so as to face a part of the upper portion 101 of each of the plurality of cells 100.

[0037] The first adhesive layer 220 is provided on the upper surface of the main body portion 210. The second adhesive layer 230 is provided on the lower surface of the main body portion 210. The buffer portion 200 is bonded to the multiple cells 100 by the second adhesive layer 230. In other words, the main body portion 210 and the multiple cells 100 are bonded to each other via the second adhesive layer 230.

[0038] The buffer section 200 may further include a plurality of elastic members 240. The plurality of elastic members 240 are made of, for example, an insulating rubber member. The plurality of elastic members 240 are respectively provided in the plurality of groove sections 215. The plurality of elastic members 240 are respectively adhered to a part of the upper portion 101 of the plurality of cells 100 via the second adhesive layer 230.

[0039] The power storage device 10 further includes a pack 300. The pack 300 houses a plurality of cells 100 and a buffer section 200. That is, the pack 300 houses a plurality of power storage modules 50. The pack 300 can be fixed to the body 2 of the vehicle 1. Specifically, the pack 300 is configured to be able to be fixed to a frame member of the body 2 of the vehicle 1.

[0040] 3, in the vehicle 1 according to this embodiment, one end of the pack 300 in the second direction D2 is fixed to the left side member 5a by a first fastening member 6a such as a bolt, and the other end of the pack 300 in the second direction D2 is fixed to the right side member 5b by a second fastening member 6b such as a bolt.

[0041] One end of the pack 300 in the second direction D2 may be fixed to the left side sill 4a, and the other end of the pack 300 in the second direction D2 may be fixed to the right side sill 4b.

[0042] As shown in Figures 3 and 4, the pack 300 is disposed below the multiple cross members 3. The pack 300 extends in a first direction D1. When viewed from the vertical direction Z, the pack 300 is disposed so as to intersect with the multiple cross members 3. The pack 300 also functions as a floor member that defines the interior of the vehicle cabin.

[0043] 5 and 6, the pack 300 includes an upper plate portion 310, a lower plate portion 320, and a peripheral wall portion 330. The upper plate portion 310 is disposed above the plurality of buffer portions 200. The upper plate portion 310 is bonded to the buffer portions 200. Specifically, a first adhesive layer 220 bonds the main body portion 210 and the upper plate portion 310 to each other.

[0044] The lower plate portion 320 is disposed below the power storage modules 50. The peripheral wall portion 330 extends downward from the outer circumferential edge of the upper plate portion 310. The peripheral wall portion 330 extends horizontally so as to surround the multiple power storage modules 50. The peripheral wall portion 330 is connected to the lower plate portion 320.

[0045] Here, a description will be given of the material that constitutes the main body 210 of the buffer section 200. In this embodiment, the main body 210 is made of a material that is more rigid than the upper plate 310.

[0046] The specific material constituting main body 210 is not particularly limited. Main body 210 is preferably a resin member, for example. The resin member preferably has a higher heat resistance temperature than the material constituting upper plate 310. The resin member preferably has a lower thermal conductivity than the material constituting upper plate 310. Using such a material for the resin member makes it possible to suppress a temperature rise in the vehicle cabin when power storage module 50 generates abnormal heat.

[0047] The resin member constituting the main body 210 may contain a thermosetting resin. The resin member may be made of glass fiber reinforced plastic. The resin member may contain a foamed resin. The foamed resin preferably has a heat resistance temperature of 400°C or higher.

[0048] The energy storage device 10 may further include a plurality of restraining members 510 in each of the plurality of energy storage modules 50. The plurality of restraining members 510 extend from one side to the other side of the energy storage module 50 in the first direction D1. A load is applied to the plurality of cells 100 in the first direction D1 by the plurality of restraining members 510. The plurality of restraining members 510 fix the relative positions of the plurality of cells 100 to one another. The plurality of restraining members 510 each cover four corners of each of the plurality of cells 100 when viewed from the first direction D1.

[0049] The energy storage device 10 may further include a cooling plate 530. The cooling plate 530 is provided below the plurality of energy storage modules 50. The cooling plate 530 may be provided above the plurality of energy storage modules 50. A flow circuit (not shown) is formed inside the cooling plate 530, through which a refrigerant such as air or a coolant can flow.

[0050] The energy storage device 10 may further include a tray 540. The tray 540 is provided below the plurality of energy storage modules 50. The energy storage device 10 may further include a third adhesive layer 550 in each of the plurality of energy storage modules 50. The third adhesive layer 550 is disposed between the plurality of cells 100 and the tray 540. The third adhesive layer 550 bonds the plurality of cells 100 and the tray 540 together.

[0051] 8, for ease of explanation, the multiple cells 100 are shown spaced apart from each other, but the multiple cells 100 may be closely spaced from each other in the first direction D1. Other members such as spacers may be interposed between the multiple cells 100.

[0052] Here, the starting point portion 201 of the buffer section 200 in the first embodiment will be further described. Fig. 9 is a partial cross-sectional view showing the energy storage device in a state in which a vertical tensile stress is generated in the buffer section in the first embodiment. Fig. 10 is a partial cross-sectional view showing the energy storage device in a state in which a vertical tensile stress is further generated in the buffer section following the state in Fig. 9. Figs. 9 and 8 partially show the energy storage device 10 in a cross-sectional view similar to that in Fig. 8.

[0053] As shown in Figures 8 to 10, the buffer section 200 is configured to be separable in the vertical direction Z when a tensile stress in the vertical direction Z is applied. In this embodiment, this separation occurs by fracture. Figures 8 to 10 specifically show the change in state when an attempt is made to peel the upper plate section 310 from the plurality of cells 100. More specifically, Figures 8 to 10 show the change in state when the upper plate section 310 is pulled upward from the vicinity of the edge 202 of the buffer section 200.

[0054] The starting point 201 is an edge 202 in the first direction D1, which serves as a starting point for separation of the buffer section 200. In this embodiment, the buffer section 200 has an opening 201A facing the first direction D1 as the starting point 201. The opening 201A may extend in a second direction D2 perpendicular to the first direction D1. As shown in FIGS. 8 to 10, the above-mentioned pulling causes a crack to form along the first direction D1 from the opening 201A toward the inside of the buffer section 200. As a result, the main body section 210 of the buffer section 200 separates in the vertical direction Z. As a result, the upper plate section 310 is peeled off from the plurality of cells 100.

[0055] As described above, the energy storage device 10 according to the first embodiment of the present disclosure can be mounted on a vehicle 1. The energy storage device 10 includes a plurality of cells 100, a buffer section 200, and an upper plate section 310. The plurality of cells 100 are arranged in a first direction D1 that is horizontal. The buffer section 200 is joined to the upper portions 101 of the plurality of cells 100. The buffer section 200 extends in the first direction D1. The upper plate section 310 is disposed above the buffer section 200. The upper plate section 310 is joined to the buffer section 200. The buffer section 200 is configured to be separable in the vertical direction Z when a tensile stress in the vertical direction Z occurs. The buffer section 200 includes a starting point section 201. The starting point section 201 is an edge 202 in the first direction D1 that serves as a starting point for separation of the buffer section 200.

[0056] According to the above configuration, the buffer portion 200 can disperse a load input from above the energy storage device 10 in the first direction D1 at the buffer portion 200, thereby increasing the rigidity of the energy storage device 10 against the input of a load from above. Furthermore, during maintenance or the like, a worker attempts to separate the upper plate portion 310 from the plurality of cells 100 by pulling the end of the upper plate portion 310 upward. At this time, the buffer portion 200 separates in the vertical direction Z starting from the starting point portion 201 (see FIGS. 9 to 11 ), so that the upper plate portion 310 can be easily separated from the plurality of cells 100. Therefore, according to the above configuration, it is possible to provide an energy storage device 10 that has high rigidity against the input of a load from above and is easy to disassemble.

[0057] Furthermore, in the first embodiment, the buffer section 200 has an opening 201A facing the first direction D1 as the starting point 201. With this configuration, when the end of the upper plate section 310 is pulled upward, a crack is likely to occur along the first direction D1 from the opening 201A toward the inside of the buffer section 200 (see FIGS. 9 to 11). This makes it easier to separate the buffer section 200 in the up-down direction Z.

[0058] Furthermore, in the first embodiment, the buffer section 200 has a plurality of gaps 203A aligned in the first direction D1. With this configuration, when the end of the upper plate section 310 is pulled upward, cracks are likely to occur inside the buffer section 200 between the opening 201A and the gaps 203A and between the gaps 203A (see FIGS. 9 to 11). This makes it even easier to separate the buffer section 200 in the up-down direction Z.

[0059] (Embodiment 2) Next, a description will be given of a power storage device according to a second embodiment of the present disclosure. The power storage device according to the second embodiment of the present disclosure differs from the power storage device 10 according to the first embodiment of the present disclosure mainly in the configuration of the buffer section. Note that the description of the same configuration and effects as those of the power storage device 10 according to the first embodiment of the present disclosure will not be repeated.

[0060] 11 is a partial cross-sectional view of an electricity storage device according to embodiment 2 of the present disclosure. In FIG. 11 and the subsequent figures, cross-sectional views of the electricity storage device are shown in the same cross-sectional view as in embodiment 1.

[0061] 11, in a power storage device 10B according to the second embodiment of the present disclosure, a buffer section 200 has a notch 201B. The notch 201B extends inward from an edge 202. The notch 201B extends over the entire buffer section 200 in the first direction D1.

[0062] The buffer section 200 includes a lower buffer section 204B and an upper buffer section 206B. The lower buffer section 204B is located below the notch. The lower buffer section 204B has a plurality of engaged sections 205B. The plurality of engaged sections 205B are each provided in the lower buffer section 204B so as to be recessed in either direction in the first direction D1. The plurality of engaged sections 205B may also be provided in the lower buffer section 204B so as to protrude in either direction in the first direction D1.

[0063] The upper buffer portion 206B is located above the notch portion. The upper buffer portion 206B has engaging portions 207B. The engaging portions 207B engage with the lower buffer portion 204B. Specifically, the engaging portions 207B are provided in the upper buffer portion 206B so as to protrude in either direction in the first direction D1. When the engaged portions 205B are provided so as to protrude, the engaging portions 207B may be provided in the upper buffer portion 206B so as to be recessed in either direction in the first direction D1.

[0064] In this embodiment, the main body portion 210 includes a lower main body portion 211B and an upper main body portion 212B. The lower main body portion 211B is the portion below the notch portion 201B. The upper main body portion 212B is the portion above the notch portion 201B. In this embodiment, the lower buffer portion 204B includes the lower main body portion 211B and the second adhesive layer 230. The upper buffer portion 206B includes the upper main body portion 212B and the first adhesive layer 220.

[0065] Here, the starting point portion 201 of the buffer portion 200 in the second embodiment will be described. FIG. 12 is a partial cross-sectional view showing the state of the energy storage device in the second embodiment when a tensile stress in the vertical direction is applied to the buffer portion. As shown in FIGS. 11 and 12, the buffer portion 200 in the second embodiment is also configured to be separable in the vertical direction Z when a tensile stress in the vertical direction Z is applied. Specifically, FIGS. 11 and 12 show the change in state when an attempt is made to peel the upper plate portion 310 from the plurality of cells 100. More specifically, FIGS. 11 and 12 show the change in state when the upper plate portion 310 is pulled upward from the vicinity of the edge 202 of the buffer portion 200.

[0066] In the second embodiment, the notch 201B functions as the starting point 201. As shown in FIGS. 11 and 12, the upper buffer section 206B is pulled upward near the edge 202 by the above-described pulling. Then, the multiple engaging sections 207B are disengaged from the lower buffer section 204B when the upper buffer section 206B is pulled upward. Specifically, the multiple engaging sections 207B are disengaged from the multiple engaged sections 205B. This causes the main body section 210 of the buffer section 200 to separate in the vertical direction Z. As a result, the upper plate section 310 is peeled off from the multiple cells 100.

[0067] In this embodiment, the main body 210 of the buffer unit 200 separates in the vertical direction Z without breaking. Therefore, in the energy storage device 10B according to the second embodiment, the lower buffer unit 204B and the upper buffer unit 206B can be easily assembled to each other, for example, during production of the energy storage device 10B.

[0068] As described above, in the power storage device 10B according to the second embodiment of the present disclosure, the buffer section 200 has, as the starting point section 201, the notched section 201B extending inward from the edge 202.

[0069] According to the above configuration, when the end of the upper plate portion 310 is pulled upward, the buffer portion 200 can be easily separated in the up-down direction Z along the cutout portion 201B.

[0070] In the second embodiment, the buffer section 200 includes a lower buffer section 204B and an upper buffer section 206B. The lower buffer section 204B is located below the notch. The upper buffer section 206B is located above the notch. The upper buffer section 206B has an engagement section 207B. The engagement section 207B engages with the lower buffer section 204B so that the engagement with the lower buffer section 204B is released when the upper buffer section 206B is pulled upward.

[0071] According to the above configuration, during normal use and not during maintenance, the engagement portion 207B engages with the lower buffer portion 204B, thereby preventing the upper buffer portion 206B and the lower buffer portion 204B from separating from each other.

[0072] (Embodiment 3) Next, a description will be given of a power storage device according to a third embodiment of the present disclosure. The power storage device according to a second embodiment of the present disclosure differs from the power storage device 10 according to the first embodiment of the present disclosure mainly in the configuration of the buffer section. Note that the description of the same configuration and effects as those of the power storage device 10 according to the first embodiment of the present disclosure will not be repeated.

[0073] Fig. 13 is a partial cross-sectional view of an energy storage device according to embodiment 3 of the present disclosure. As shown in Fig. 13, in an energy storage device 10C according to embodiment 3 of the present disclosure, a first adhesive layer 220 includes a strong adhesive portion 221C and a weak adhesive portion 222C. The weak adhesive portion 222C serves as a starting point 201 and bonds the main body portion 210 and the upper plate portion 310 to each other with a bonding strength weaker than that of the strong adhesive portion 221C.

[0074] Fig. 14 is a partial cross-sectional view showing the energy storage device in a state where a vertical tensile stress is applied to the buffer section in embodiment 3. Fig. 15 is a partial cross-sectional view showing the energy storage device in a state where a vertical tensile stress is further applied to the buffer section following the state shown in Fig. 14.

[0075] 13 to 15, according to the above configuration, when the end of the upper plate portion 310 is pulled upward, the first adhesive layer 220 and the main body portion 210 can be easily separated in the up-down direction Z, starting from the release of the bond between the weakly bonded portion 222C and the main body portion 210. Furthermore, during normal use other than maintenance, the strongly bonded portion 221C can prevent the bond between the first adhesive layer 220 and the main body portion 210 from being released.

[0076] Furthermore, in this embodiment, the first adhesive layer 220 includes a plurality of strong adhesive portions 221C and a plurality of weak adhesive portions 222C including the weak adhesive portions 222C serving as the above-described starting portions 201. The strong adhesive portions 221C and the weak adhesive portions 222C are arranged alternately in the first direction D1.

[0077] According to the above configuration, it is possible to achieve a balance between the ease of separation between the first adhesive layer 220 and the main body portion 210 and the bonding strength between the first adhesive layer 220 and the main body portion 210.

[0078] In the above description of the embodiments, configurations that can be combined may be combined with each other.

[0079] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0080] REFERENCE SIGNS LIST 1 vehicle, 2 vehicle body, 3 cross member, 4a left side sill, 4b right side sill, 5a left side member, 5b right side member, 6a first fastening member, 6b second fastening member, 10, 10B, 10C energy storage device, 50 energy storage module, 100 cell, 101 upper portion, 102 first end surface portion, 103 second end surface portion, 104 bottom surface portion, 105 first side surface portion, 106 second side surface portion, 110 electrode body, 120 cell case, 200 buffer portion, 201 starting point portion, 201A opening portion, 201B notch portion, 202 edge, 203A gap portion, 204B lower buffer portion, 205B engaged portion, 206B upper buffer portion, 207B engaging portion, 210 main body portion, 211B Lower body portion, 212B upper body portion, 215 groove portion, 220 first adhesive layer, 221C strong adhesive portion, 222C weak adhesive portion, 230 second adhesive layer, 240 elastic member, 300 pack, 310 upper plate portion, 320 lower plate portion, 330 peripheral wall portion, 510 restraining member, 530 cooling plate, 540 tray, 550 third adhesive layer, D1 first direction, D2 second direction, Z vertical direction.

Claims

1. A power storage device that can be mounted on a vehicle, A plurality of cells arranged in a first direction along the horizontal direction; a buffer portion joined to an upper portion of each of the plurality of cells and extending in the first direction; an upper plate portion disposed above the buffer portion and joined to the buffer portion; The buffer portion is configured to be separable in the vertical direction when a tensile stress in the vertical direction occurs, The buffer portion has a starting point portion at an edge in the first direction, which serves as a starting point for separation of the buffer portion.

2. The power storage device according to claim 1 , wherein the buffer portion has, as the starting point portion, an opening portion facing the first direction.

3. The power storage device according to claim 2 , wherein the buffer portion has a plurality of gaps aligned in the first direction.

4. The power storage device according to claim 1 , wherein the buffer portion has, as the starting point portion, a notch portion extending inward from the edge.

5. the buffer portion includes a lower buffer portion located below the cutout portion and an upper buffer portion located above the cutout portion, The power storage device according to claim 4 , wherein the upper buffer portion has an engaging portion that engages with the lower buffer portion so that the engagement with the lower buffer portion is released when the upper buffer portion is pulled upward.

6. The buffer section is a plate-shaped main body portion extending in the first direction; an adhesive layer that bonds the main body portion and the upper plate portion together, The power storage device according to claim 1 , wherein the adhesive layer includes a strong adhesive portion and a weak adhesive portion that serves as the starting point and bonds the main body portion and the upper plate portion together with a bonding strength weaker than that of the strong adhesive portion.

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