Power storage device

Abstract

This power storage device comprises an adhesive layer (29) that fixes at least one power storage cell (11) to an accommodation case. The accommodation case includes a first main wall and a second main wall that are arranged in the vertical direction. The adhesive layer (29) bonds at least one power storage cell 11 to the first main wall. The at least one power storage cell (11) includes first portions (PA1, PA2) located on the outer peripheral edge-side of the first main wall, and a second portion (PA3) located closer to the center of the first main wall than the first portions (PA1, PA2). The adhesive layer (29) includes first adhesive portions (60, 61) for fixing the first portions (PA1, PA2) to the first main wall, and a second adhesive portion (62) for fixing the second portion (PA3) to the first main wall.

Description

Power storage device

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

[0002] Various types of power storage devices have been proposed in the past. For example, the power storage device described in Japanese Patent Laid-Open Publication No. 2023-14517 includes a lower case, a plurality of battery cells arranged on the upper surface of the lower case, and a heat transfer member arranged between the lower case and the battery cells.

[0003] Japanese Patent Application Laid-Open No. 2023-14517

[0004] In an electricity storage device including a plurality of electricity storage cells and a housing case, it is conceivable to use an adhesive to fix the electricity storage cells to the housing case.

[0005] On the other hand, when an external force is applied to the electricity storage device, there is a risk that part of the adhesive (particularly the outer periphery) may peel off.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an energy storage device that includes an energy storage cell, a housing case, and an adhesive for fixing the energy storage cell to the housing case, in which peeling of the adhesive is suppressed.

[0007] The power storage device includes a housing case, at least one power storage cell housed in the housing case, and an adhesive layer that fixes the at least one power storage cell to the housing case.

[0008] The storage case includes a first main wall and a second main wall arranged in the vertical direction, and an adhesive layer adheres the storage cells to the first main wall, and at least one storage cell includes a first portion located on the outer peripheral edge side of the first main wall and a second portion located closer to the center of the first main wall than the first portion, and the adhesive layer includes a first adhesive portion that fixes the first portion to the first main wall and a second adhesive portion that fixes the second portion to the first main wall, and the Young's modulus of the first adhesive portion is smaller than the Young's modulus of the second adhesive portion.

[0009] In the above-described energy storage device, when the outer peripheral edge of the first main wall is deformed to bend downward, the first adhesive portion has a small Young's modulus, so the first adhesive portion stretches well. This prevents the first adhesive portion from peeling off. Meanwhile, the second connection portion has a large Young's modulus and high hardness. This strengthens the bond between the first main wall and the energy storage cell.

[0010] According to the energy storage device of the present disclosure, in an energy storage device including an energy storage cell, a housing case, and an adhesive for fixing the energy storage cell to the housing case, peeling of the adhesive can be suppressed.

[0011] 1 is a side view that schematically shows a vehicle that includes an energy storage device according to a first embodiment. FIG. 2 is an exploded perspective view that schematically shows an energy storage device 2 and a vehicle frame 3. FIG. 3 is an exploded perspective view that shows the energy storage device 2. FIG. 4 is a perspective view that shows a lower case 12. FIG. 5 is a perspective view that schematically shows an energy storage cell 11. FIG. 6 is a plan view that shows the underside of the energy storage cell 11. FIG. 7 is a plan view that shows a bottom plate 14, an adhesive layer 29, and the energy storage cell 11. FIG. 8 is a graph that shows the physical properties of various adhesives. FIG. 9 is a cross-sectional view that shows a portion of the energy storage device 2A. FIG. 10 is a cross-sectional view that shows a portion of the energy storage device 2B.

[0012] An energy storage device according to the present embodiment will be described with reference to FIGS. 1 to 11 . Hereinafter, an embodiment and modified examples according to the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated. Note that the embodiment and modified examples described below may be selectively combined as appropriate.

[0013] (First Embodiment) Fig. 1 is a side view that schematically shows a vehicle that includes a power storage device according to a first embodiment. Referring to Fig. 1, a power storage device 2 according to the first embodiment is disposed below a floor panel of a vehicle 1. Examples of the vehicle 1 include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. The vehicle 1 includes the power storage device 2 and a vehicle frame 3.

[0014] Fig. 2 is an exploded perspective view schematically showing the power storage device 2 and the vehicle frame 3. Referring to Fig. 2, the vehicle frame 3 includes a left roof rail 30, a right roof rail 31, a left frame 32, a right frame 33, a first left pillar 34, a second left pillar 35, a third left pillar 36, a first right pillar 37, a second right pillar 38, and a third right pillar 39.

[0015] The left roof rail 30 and the right roof rail 31 are disposed above the vehicle frame 3. The left roof rail 30 and the right roof rail 31 are disposed at an interval in the width direction D2 of the vehicle 1 (see FIG. 1 ). The left roof rail 30 and the right roof rail 31 are disposed so as to extend in the front-rear direction D1 of the vehicle 1. A direction D3 indicates the height direction of the vehicle 1.

[0016] The left frame 32 and the right frame 33 are disposed at the bottom of the vehicle frame 3. The left frame 32 and the right frame 33 are disposed at an interval in the width direction D2 of the vehicle 1. The left frame 32 and the right frame 33 are also disposed so as to extend in the front-rear direction D1 of the vehicle 1.

[0017] The first left pillar 34, the second left pillar 35, and the third left pillar 36 are disposed on the left side surface of the vehicle frame 3. The first left pillar 34 is disposed to connect the front end of the left frame 32 to the front end of the left roof rail 30. The second left pillar 35 is disposed to connect the center of the left frame 32 to the center of the left roof rail 30. The third left pillar 36 is disposed to connect the rear end of the left frame 32 to the rear portion of the left roof rail 30. In other words, the second left pillar 35 is disposed rearward from and spaced apart from the first left pillar 34, and the third left pillar 36 is disposed rearward from and spaced apart from the second left pillar 35.

[0018] The first right pillar 37, the second right pillar 38, and the third right pillar 39 are disposed on the right side of the vehicle frame 3. The first right pillar 37 is disposed to connect the front end of the right frame 33 to the front end of the right roof rail 31. The second right pillar 38 is disposed to connect the center of the right frame 33 to the center of the right roof rail 31. The third right pillar 39 is disposed to connect the rear end of the right frame 33 to the rear portion of the right roof rail 31. In other words, the second right pillar 38 is disposed rearward from and spaced apart from the first right pillar 37, and the third right pillar 39 is disposed rearward from and spaced apart from the second right pillar 38.

[0019] A floor panel 4 is provided between the left frame 32 and the right frame 33. The power storage device 2 is disposed below the floor panel 4 and fixed to the left frame 32 and the right frame 33.

[0020] 3 is an exploded perspective view showing the energy storage device 2. The energy storage device 2 includes a housing case 10 and a plurality of energy storage cells 11. The housing case 10 includes a lower case 12 and an upper case 13. The lower case 12 is formed to open upward, and the upper case 13 is disposed on the lower case 12 so as to close the opening of the lower case 12. In the example shown in this figure, the upper case 13 is formed in a plate shape.

[0021] The lower case 12 includes a bottom plate 14, a peripheral wall 15, a partition wall 26, and an adhesive layer 29, which will be described later.

[0022] The bottom plate 14 and the upper case 13 are arranged in the up-down direction D3. In this embodiment, the bottom plate 14 is a "first main wall" and the upper case 13 is a "second main wall."

[0023] 4 is a perspective view showing the lower case 12. The bottom plate 14 is formed in a substantially rectangular shape. The outer peripheral edge of the bottom plate 14 includes a front edge 20, a rear edge 21, a side edge 22, and a side edge 23. The front edge 20 is located on the front side of the vehicle 1, and the rear edge 21 is located on the rear side of the vehicle 1. The side edges 22 and 23 are spaced apart in the width direction D2, and are formed to extend in the front-rear direction D1.

[0024] The peripheral wall 15 is formed to extend upward from the outer peripheral edge of the bottom plate 14. The peripheral wall 15 is formed in an annular shape and includes a front wall 16, a rear wall 17, a side wall 18, and a side wall 19.

[0025] The front wall 16 is formed on the front edge 20, and the rear wall 17 is formed on the rear edge 21. The side wall 18 is formed on the side edge 22, and the side wall 19 is formed on the side edge 23.

[0026] A plurality of support portions 24 are formed at intervals in the width direction D2 on the outer surface of the side wall 18. A plurality of support portions 25 are formed at intervals in the width direction D2 on the outer surface of the side wall 19.

[0027] The support portion 24 is fixed to a left frame 32 shown in FIG. 1 by a plurality of bolts, and the support portion 25 is fixed to a right frame 33 by a plurality of bolts.

[0028] The partition wall 26 divides the space within the storage case 10 into storage spaces 27 and 28, which are arranged in the front-to-rear direction D1. The partition wall 26 is provided to connect the center of the side wall 18 in the front-to-rear direction D1 to the center of the side wall 19 in the front-to-rear direction D1.

[0029] 3, the plurality of storage cells 11 are accommodated in the accommodation space 27 and the accommodation space 28. Each storage cell 11 is formed to be elongated in the width direction D2. The plurality of storage cells 11 are arranged in an array in the front-rear direction D1.

[0030] 5 is a perspective view schematically showing the energy storage cell 11. The energy storage cell 11 is formed to be elongated in a width direction D2. In this embodiment, the width direction D2 is the "longitudinal direction" of the energy storage cell 11. The front-rear direction D1 is the "width direction" of the energy storage cell 11. The energy storage cell 11 includes a cell case 40 and a coating film 41.

[0031] The cell casing 40 includes a top plate 42 , a bottom plate 43 , a side plate 44 , a side plate 45 , an end plate 46 , an end plate 47 , a terminal 48 , and a terminal 49 .

[0032] The top plate 42 is located on the top surface of the cell case 40, and the bottom plate 43 is located on the bottom surface of the cell case 40. The top plate 42 and the bottom plate 43 are arranged in the up-down direction D3, and the side plates 44 and 45 are arranged in the front-to-rear direction D1. The side plates 44 and 45 are formed elongated in the width direction D2. The end plates 46 and 47 are arranged in the width direction D2. The terminal 48 is provided on the end plate 46, and the terminal 49 is provided on the end plate 47.

[0033] The coating film 41 is provided to cover the surface of the cell case 40. The coating film 41 is made of an insulating material and electrically insulates adjacently arranged energy storage cells 11. The terminals 48 and 49 are exposed to the outside from the coating film 41.

[0034] 6 is a bottom view showing the lower surface of the energy storage cell 11 and the bottom plate 14. The energy storage cell 11 includes a first portion PA1 located on the end plate 46 side, a first portion PA2 located on the end plate 47 side, and a second portion PA3 located closer to the center in the width direction D2 than the first portions PA1 and PA2.

[0035] Here, the first portion PA1 is disposed on the side edge 22 side of the bottom plate 14, and the first portion PA2 is disposed on the side edge 23 side of the bottom plate 14. The second portion PA3 is disposed closer to the center of the lower case 12 than the first portion PA1 and the first portion PA2.

[0036] Here, the total length of the energy storage cell 11 in the width direction D2 is defined as the total length Wf. The lengths WP1 and WP2 of the first portions PA1 and PA2 in the width direction D2 are 10% to 20% of the total length Wf. Alternatively, the lengths WP1 and WP2 may be 15% to 20% of the total length Wf.

[0037] A plurality of holes 50 are formed in the coating film 41 in a portion where the first portion PA1 is located. A plurality of holes 51 are formed in the coating film 41 in a portion where the first portion PA2 is located. Holes 50 of the coating film 41 are formed on the side of the end plate 46, and holes 51 are formed on the side of the end plate 47. A portion of the bottom plate 43 is exposed from the coating film 41 through holes 50 and 51.

[0038] Fig. 7 is a plan view showing the bottom plate 14, the adhesive layer 29, and the storage cells 11. In Fig. 6, one storage cell 11 is shown by a dashed line.

[0039] The adhesive layer 29 includes first adhesive portions 60 and 61 and a second adhesive portion 62. In Fig. 6, the adhesive layer 29 is hatched to make it easier to see.

[0040] The first adhesive portion 60 is formed to extend in the front-rear direction D1 along the side edge 22. The first adhesive portion 61 is formed to extend in the front-rear direction D1 along the side edge 23.

[0041] 7 , when the energy storage cell 11 and the first adhesive portions 60, 61 are viewed in plan from above, the first portion PA1 of the energy storage cell 11 is located at the first adhesive portion 60, and the first portion PA2 is located at the first adhesive portion 61. The second adhesive portion 62 is located at the second portion PA3 of the energy storage cell 11.

[0042] Therefore, the portions of the bottom plate 43 exposed through the holes 50 and 51 are adhered to the bottom plate 14 of the lower case 12 by the first adhesive portions 60 and 61 .

[0043] On the other hand, the portion of the coating film 41 located on the bottom plate 43 that is located between the holes 50 and 51 is located in the second adhesive portion 62. The second adhesive portion 62 adheres the portion of the coating film 41 located on the bottom plate 43 that is located between the holes 50 and 51 to the bottom plate 14.

[0044] The length of the first adhesive portion 60 in the width direction D2 is a width W0. The length of the first adhesive portion 61 in the width direction D2 is a width W1.

[0045] Here, the total length of the energy storage cell 11 in the width direction D2 is defined as the total length Wf. Each of the widths W0 and W1 is 10% to 20% of the total length Wf. Each of the widths W0 and W1 may be 15% to 20% of the total length Wf.

[0046] The first adhesive portion 60 includes a plurality of divided adhesive portions 66. The plurality of divided adhesive portions 66 are arranged at intervals in the width direction D2. The first adhesive portion 61 also includes a plurality of divided adhesive portions 67. The plurality of divided adhesive portions 67 are arranged at intervals in the width direction D2.

[0047] When the dividing adhesive portion 66 and the energy storage cell 11 are viewed in plan from a position spaced apart in the vertical direction D3, the dividing adhesive portion 66 is arranged to pass through the hole 50. Similarly, when the dividing adhesive portion 67 and the energy storage cell 11 are viewed in plan from a position spaced apart in the vertical direction D3, the dividing adhesive portion 67 is arranged to pass through the hole 51.

[0048] The length of the divided adhesive portion 66 in the width direction D2 is width W16. The length of the divided adhesive portion 67 in the width direction D2 is width W17. Note that each of the widths W16 and W17 is, for example, approximately 25 mm. The distance between adjacent divided adhesive portions 66 in the width direction D2 is distance L10. Distance L10 is equal to or greater than 20 mm and smaller than 25 mm. Distance L10 is narrower than each of the widths W16 and W17.

[0049] The second adhesive portion 62 is located closer to the center of the bottom plate 14 in the width direction D2 than the first adhesive portion 60 and the first adhesive portion 61. The second adhesive portion 62 is also formed to extend in the front-rear direction D1. The length of the second adhesive portion 62 in the width direction D2 is a width W2. The width W2 of the second adhesive portion 62 is greater than the sum of the width W0 of the first adhesive portion 60 and the width W1 of the first adhesive portion 61.

[0050] The second adhesive portion 62 includes a central adhesive portion 63 and intermediate adhesive portions 64 and 65. An imaginary line L passes through the center of the bottom plate 14 in the width direction D2 and extends in the front-rear direction D1.

[0051] The central adhesive portion 63 is provided at a position where the imaginary line L passes. The intermediate adhesive portion 64 is disposed between the first adhesive portion 60 and the central adhesive portion 63. The intermediate adhesive portion 65 is disposed between the first adhesive portion 61 and the central adhesive portion 63.

[0052] The distance between the second adhesive portion 62 and the first adhesive portion 60 in the width direction D2 is the interval L1. Specifically, the distance between the intermediate adhesive portion 64 and the first adhesive portion 60 is the interval L1. The distance between the second adhesive portion 62 and the first adhesive portion 61 in the width direction D2 is the interval L2. Specifically, the distance between the intermediate adhesive portion 65 and the first adhesive portion 61 is the interval L2.

[0053] Each of the intervals L1 and L2 is longer than each of the widths W16 and W17. For example, each of the intervals L1 and L2 is about 30 mm, and each of the widths W16 and W17 is about 25 mm.

[0054] The distance between the intermediate adhesive portion 64 and the central adhesive portion 63 in the width direction D2 is a distance L3. The distance between the intermediate adhesive portion 65 and the central adhesive portion 63 in the width direction D2 is a distance L4.

[0055] The length of the central adhesive portion 63 in the width direction D2 is a width W3. The length of the intermediate adhesive portion 64 in the width direction D2 is a width W4. The length of the intermediate adhesive portion 65 in the width direction D2 is a width W5. Here, the width W3 is longer than the combined value of the widths W4 and W5.

[0056] The central adhesive portion 63 includes a plurality of divided adhesive portions 68. The length of the divided adhesive portions 68 in the width direction D2 is a width W18. The intermediate adhesive portion 64 includes a plurality of divided adhesive portions 69. The length of the divided adhesive portions 69 in the width direction D2 is a width W19. The intermediate adhesive portion 65 includes a plurality of divided adhesive portions 70. The length of the divided adhesive portions 70 in the width direction D2 is a width W20.

[0057] The distances L3 and L4 are longer than the widths W18, W19, and W20, respectively. The distances L3 and L4 are approximately 30 mm, and the widths W18, W19, and W20 are approximately 25 mm.

[0058] The interval between the divided adhesive portions 68 is L11, and the interval between the divided adhesive portions 69 is L12. The intervals L11 and L12 are narrower than the widths W18, W19, and W20, respectively.

[0059] The first adhesive portions 60 and 61, the second adhesive portion 62, and the central adhesive portion 63 are made of adhesive. The Young's modulus of the first adhesive portions 60 and 61 is smaller than that of the second adhesive portion 62. The Young's modulus of the intermediate adhesive portions 64 and 65 is smaller than that of the central adhesive portion 63.

[0060] Fig. 8 is a graph showing the physical properties of various adhesives. The vertical axis shows the results (hardness) of the durometer hardness test (Type E, Type D, Type A) according to JIS K 6253-1997 (Testing Method for Hardness of Vulcanized Rubber and Thermoplastic Rubber). The horizontal axis shows the viscosity of the various adhesives.

[0061] In rubber such as adhesives, there is a correlation between hardness and Young's modulus, and as hardness increases, Young's modulus also increases.

[0062] The hardness (Young's modulus) of the first adhesive portions 60 and 61 is smaller than the hardness (Young's modulus) of the second adhesive portion 62 .

[0063] For example, in JIS K 6253-1997 (Testing Method for Hardness of Vulcanized Rubber and Thermoplastic Rubber, Durometer Hardness Test (Type D)), the first adhesive portions 60, 61 employ an adhesive having a hardness of 50 or less. Note that the first adhesive portions 60, 61 may employ an adhesive having a hardness of 10 or more and 95 or less in Type A.

[0064] The second adhesive portion 62 employs an adhesive having a hardness of greater than 50 in Type D. The central adhesive portion 63 may employ an adhesive having a higher Young's modulus (hardness) than the intermediate adhesive portion 64. For example, the central adhesive portion 63 may employ an adhesive having a hardness of 95 or more and 100 or less in Type D, and the intermediate adhesive portion 64 may employ an adhesive having a hardness of greater than 50 and less than 95 in Type D.

[0065] For example, TB1539 (a silicone adhesive: adhesive P34) can be used for the first adhesive portions 60 and 61, and TB2237J (an epoxy adhesive: adhesive P32) or TB2270J (an epoxy adhesive: adhesive P35) can be used for the second adhesive portion 62. Alternatively, TB2270J (an epoxy adhesive: adhesive P35) can be used for the central adhesive portion 63, and TB2237J (an epoxy adhesive: adhesive P32) can be used for the adhesive P32 of the intermediate adhesive portion 64.

[0066] Note that TB1539 (a silicone-based adhesive: adhesive P34), TB2237J (an epoxy-based adhesive: adhesive P32), and TB2270J (an epoxy-based adhesive: adhesive P35) have similar viscosities and can be cured by heat curing. Therefore, when the first adhesive portions 60, 61 and the second adhesive portion 62 are formed by applying each adhesive to the upper surface of the bottom plate 14, the similar viscosities allow the shape changes of each adhesive to be similar. Furthermore, because the curing method for each adhesive is the same, the process of adhering the energy storage cell 11 to the bottom plate 14 can be simplified.

[0067] It should be noted that various combinations of adhesives can be used for the first adhesive portions 60 and 61 and the second adhesive portion 62 .

[0068] For example, TB1535B (a silicone adhesive: adhesive P31) may be used for the first adhesive portions 60 and 61, and TB2955P (a silicone adhesive: adhesive P33) may be used for the second adhesive portion 62.

[0069] Since all of the above adhesives are moisture-curing adhesives, the energy storage cells 11 can be easily fixed to the bottom plate 14 .

[0070] In FIG. 8, adhesive P1 is TB1375N (acrylic adhesive: UV curing). Adhesive P2 is TB3350 (acrylic adhesive). Adhesive P3 is TB30662U (acrylic adhesive: UV curing). Adhesive P4 is TB7737 (room temperature curing). Adhesive P5 is TB3020B (acrylic adhesive: UV curing). Adhesive P6 is TB3027G (acrylic adhesive: UV curing). Adhesive P7 is TB3955 (two-component mixed curing). Adhesive P8 is TB3074C (acrylic adhesive: UV curing). Adhesive P9 is TB3065E (acrylic adhesive: UV curing). Adhesive P10 is TB1357K (acrylic adhesive: UV curing). The adhesive P11 is TB3017F (acrylic adhesive: UV curing). The adhesive P12 is TB1230G (silicon adhesive: two-component mixed curing). The adhesive P13 is TB3164D (epoxy adhesive: UV curing). The adhesive P14 is TB2206S (epoxy adhesive: heat curing). The adhesive P15 is TB3331D (heat curing). The adhesive P16 is TB3114J (epoxy adhesive: UV curing). The adhesive P17 is TB3033L (acrylic adhesive: UV curing). The adhesive P18 is TB2087 (epoxy adhesive: two-component mixed curing). The adhesive P19 is TB1225B (silicon adhesive: moisture curing). The adhesive P20 is TB3017B (acrylic adhesive: UV curing). Adhesive P21 is TB3013Q (acrylic adhesive: UV curing). Adhesive P22 is TB1535C (silicone adhesive: moisture curing). Adhesive P23 is TB1535D (silicone adhesive: moisture curing). Adhesive P24 is TBTB2222P (epoxy adhesive: heat curing). Adhesive P25 is TB2235L (epoxy adhesive: heat curing). Adhesive P26 is TB3304J (epoxy / acrylic adhesive: heat curing). Adhesive P27 is TB1225C (silicone adhesive: moisture curing). Adhesive P28 is TB1535 (silicone adhesive: moisture curing). Adhesive P29 is TB1220G (silicone adhesive: moisture curing). Adhesive P30 is TB3081L (UV curing).Adhesive P31 is TB1535B (silicone adhesive). Adhesive P32 is TB2237J (epoxy adhesive: heat curing). Adhesive P33 is TB2955P (silicone adhesive: moisture curing). Adhesive P34 is TB1539 (silicone adhesive: heat curing). Adhesive P35 is TB2270J (epoxy adhesive: heat curing). Adhesive P36 is TB1533F (silicone adhesive: moisture curing). Adhesive P37 is TB3166 (epoxy adhesive: UV curing). Adhesive P38 is TB3081P (acrylic adhesive: UV curing). Adhesive P39 is TB1153E (acrylic adhesive: heat curing).

[0071] FIG. 9 is a cross-sectional view showing the lower case 12, the side wall 18, and the energy storage cell 11. A first adhesive portion 60 and a second adhesive portion 62 are formed on the lower surface of the energy storage cell 11. As shown in FIG. 9, the side wall 18 is hollow. Specifically, a plurality of hollow portions are formed inside the side wall 18 and arranged in the up-down direction D3. The support portion 24 is also hollow. Specifically, a plurality of hollow portions are formed inside the support portion 24 and arranged in the width direction D2. The left frame 32 is also hollow.

[0072] In vehicle 1 configured as described above, an external force may be applied to power storage device 2 from outside vehicle 1 .

[0073] The dashed lines in FIG. 9 virtually show the state in which the bottom plate 14 of the lower case 12 is deformed when an external force is applied to the power storage device 2.

[0074] The bottom plate 14 is deformed so that the side edge 22 of the bottom plate 14 faces downward. When the bottom plate 14 is deformed in this way, the distance between the bottom plate 14 of the lower case 12 and the bottom plate 43 of the energy storage cell 11 in the up-down direction D3 increases from the center of the bottom plate 14 toward the side edge 22 in the front-rear direction D1.

[0075] On the other hand, the first adhesive portion 60 has a higher Young's modulus than the second adhesive portion 62. The first adhesive portion 60 is more likely to deform and stretch than the second adhesive portion 62.

[0076] Therefore, even if the bottom plate 14 attempts to deform, as shown by the dashed line in Figure 9, it is possible to prevent the first adhesive portion 60 from peeling off from the bottom plate 14 or the bottom plate 43, or from breaking.

[0077] Furthermore, the first adhesive portion 60 has a plurality of divided adhesive portions 66 arranged at intervals. Therefore, even if the divided adhesive portion 66A closest to the side edge 22 peels off, other divided adhesive portions 66 adjacent to this divided adhesive portion 66 are prevented from peeling off in conjunction with the peeling of the divided adhesive portion 66A.

[0078] The second adhesive portion 62 is located closer to the center of the bottom plate 14 in the width direction D2 than the first adhesive portion 60. Therefore, when the side edge 22 of the bottom plate 14 is displaced downward, the displacement of the second adhesive portion 62 in the up-down direction D3 is smaller than the displacement of the first adhesive portion 60.

[0079] This prevents the central adhesive portion 63 from peeling off from the bottom plate 14 or from breaking.

[0080] On the other hand, the central adhesive portion 63 has a higher Young's modulus than the first adhesive portion 60 , and therefore the central adhesive portion 63 firmly bonds the energy storage cell 11 and the lower case 12 together.

[0081] The distance L1 between the first adhesive portion 60 and the second adhesive portion 62 is longer than the width W16 of the divided adhesive portion 66.

[0082] Since the second adhesive portion 62 is arranged at a distance from the first adhesive portion 60, even if the first adhesive portion 60 peels off, the second adhesive portion 62 is prevented from peeling off along with the peeling of the first adhesive portion 60.

[0083] The intermediate adhesive portion 64 of the second adhesive portion 62 is formed by a plurality of divided adhesive portions 69. Therefore, even if one divided adhesive portion 69 peels off from the bottom plate 14, the peeling can be prevented from spreading to the other divided adhesive portions 69. The intermediate adhesive portion 64 has a higher Young's modulus than the first adhesive portion 60. Therefore, the intermediate adhesive portion 64 firmly fixes the energy storage cell 11 to the lower case 12.

[0084] The central adhesive portion 63 is located closer to the center of the bottom plate 14 in the width direction D2 than the intermediate adhesive portion 64.

[0085] The central adhesive portion 63 is located closer to the center of the bottom plate 14 in the width direction D2 than the intermediate adhesive portion 64. Therefore, when the side edge 22 of the bottom plate 14 is displaced downward, the displacement amount of the central adhesive portion 63 in the up-down direction D3 is smaller than the displacement amount of the intermediate adhesive portion 64.

[0086] This prevents the central adhesive portion 63 from peeling off from the bottom plate 14 or breaking. On the other hand, the Young's modulus of the central adhesive portion 63 is higher than the Young's modulus of the intermediate adhesive portion 64, and the central adhesive portion 63 has a higher hardness. Therefore, the central adhesive portion 63 firmly fixes the energy storage cell 11 to the lower case 12.

[0087] The central adhesive portion 63 also includes a plurality of divided adhesive portions 68. Therefore, even if one divided adhesive portion 68 peels off, the peeling is prevented from spreading to the other divided adhesive portions 68.

[0088] Second Embodiment A power storage device 2A according to a second embodiment will be described with reference to Fig. 10 and other figures. Fig. 10 is a cross-sectional view showing a portion of the power storage device 2A. The power storage device 2A includes a bottom plate 14A and an adhesive layer 29A.

[0089] The bottom plate 14A includes a main plate 82, a recess 80, and a recess 81. The adhesive layer 29A includes a first adhesive portion 60A, a first adhesive portion 61A, and a second adhesive portion 62A.

[0090] The second adhesive portion 62A is located on the upper surface of the main plate 82. The recess 80 is formed on the side edge 22 side of the main plate 82, and is formed so as to protrude downward from the main plate 82.

[0091] The recess 81 is formed on the side edge 23 side of the main plate 82, and is formed so as to protrude downward from the main plate 82. The first adhesive portion 60A is located in the recess 80, and the first adhesive portion 61A is located in the recess 81.

[0092] In the up-down direction D3, the thicknesses Th0 and Th1 of the first adhesive portions 60A and 61A are greater than the thickness Th2 of the second adhesive portion 62A.

[0093] The length over which the first adhesive portions 60A, 61A can extend in the vertical direction D3 without peeling off from the bottom plate 14 is longer than the length over which the second adhesive portion 62A can extend in the vertical direction D3 without peeling off from the bottom plate 14.

[0094] Therefore, even if the bottom plate 14 is deformed so that the side edges of the bottom plate 14 are displaced downward, the first adhesive portions 60A, 61A are prevented from peeling off.

[0095] (Modification) In the first and second embodiments described above, the adhesive layers 29 and 29A fix the storage cells 11 to the lower case 12, but they may also fix the storage cells 11 to the upper case 13.

[0096] Fig. 11 is a cross-sectional view showing a portion of a power storage device 2B. The power storage device 2B includes an adhesive layer 29B, and the adhesive layer 29B fixes a plurality of power storage cells 11 to an upper case 13. In the example shown in Fig. 11, the upper case 13 is the "first main wall" and the bottom plate 14 is the "second main wall."

[0097] In this example, a recess may be formed in the upper case 13, as in the second embodiment, to make the thickness of the first adhesive portion 60B thicker than the thickness of the first adhesive portion 61B.

[0098] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure 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.

[0099] REFERENCE SIGNS LIST 1 Vehicle, 2, 2A, 2B Energy storage device, 3 Vehicle frame, 4 Floor panel, 10 Storage case, 11 Energy storage cell, 12 Lower case, 13 Upper case, 14, 14A, 43 Bottom plate, 15 Peripheral wall, 16 Front wall, 17 Rear wall, 18, 19 Side wall, 20 Front edge, 21 Rear edge, 22, 23 Side edge, 24, 25 Support portion, 26 Partition wall, 27, 28 Storage space, 29, 29A, 29B Adhesive layer, 30 Left roof rail, 31 Right roof rail, 32 Left frame, 33 Right frame, 34 First left pillar, 35 Second left pillar, 36 Third left pillar, 37 First right pillar, 38 Second right pillar, 39 Third right pillar, 40 Cell case, 41 Coating film, 42 Upper plate, 44, 45 Side plate, 46, 47 End plate, 48, 49 Terminal, 50, 51 Hole, 60, 60A, 60B, 61, 61A, 61B First adhesive part, 62, 62A Second adhesive part, 63 Center adhesive part, 64, 65 Intermediate adhesive part, 66, 66A, 67, 68, 69, 70 Divided adhesive portion, 80, 81 recessed portion, 82 main plate.

Claims

1. An energy storage device comprising: a storage case; at least one energy storage cell at least partially contained within the storage case; and an adhesive layer fixing the at least one energy storage cell to the storage case, wherein the storage case includes a first main wall and a second main wall arranged in a vertical direction, the adhesive layer bonds the at least one energy storage cell to the first main wall, the at least one energy storage cell including a first portion located on the outer peripheral edge side of the first main wall and a second portion located closer to the center of the first main wall than the first portion, the adhesive layer including a first adhesive portion fixing the first portion to the first main wall and a second adhesive portion fixing the second portion to the first main wall, and the Young's modulus of the first adhesive portion is smaller than the Young's modulus of the second adhesive portion.

2. The power storage device according to claim 1, wherein the width of the first adhesive portion is smaller than the width of the second adhesive portion.

3. The power storage device according to claim 1, wherein the first adhesive portion and the second adhesive portion are formed with a gap therebetween.

4. The energy storage device according to claim 1, wherein the first adhesive portion includes a plurality of first divided adhesive portions arranged at intervals in the longitudinal direction of the at least one energy storage cell.

5. The energy storage device according to claim 1, wherein the second adhesive portion includes a plurality of second divided adhesive portions spaced apart in the longitudinal direction of the at least one energy storage cell.

6. The energy storage device according to claim 1, wherein the second adhesive portion includes a central adhesive portion and an intermediate adhesive portion disposed between the central adhesive portion and the first adhesive portion, and the Young's modulus of the intermediate adhesive portion is smaller than the Young's modulus of the central adhesive portion.

7. The energy storage device according to claim 6, wherein the length of the central adhesive portion is longer than the length of the intermediate adhesive portion in the longitudinal direction of the at least one energy storage cell.

8. The energy storage device according to claim 1, wherein the at least one energy storage cell is formed long in the longitudinal direction, a plurality of the at least one energy storage cells are provided in the arrangement direction, and the first adhesive portion and the second adhesive portion are formed to extend in the arrangement direction.

9. The energy storage device according to claim 1, wherein the at least one energy storage cell includes a cell case and a coating film that covers the outer peripheral surface of the cell case, and the coating film has a plurality of holes formed in a portion located at the first portion.

10. The energy storage device according to claim 1, wherein, in the longitudinal direction of said at least one energy storage cell, the length of said at least one energy storage cell is the total length, and the width of said first adhesive portion is 10% or more and 20% or less of said total length.

11. The energy storage device according to claim 1, wherein the first adhesive portion is a silicone adhesive, and the second adhesive portion is an acrylic adhesive or an epoxy adhesive.

12. An energy storage device comprising: a storage case; at least one storage cell stored in the storage case; and an adhesive layer that fixes the at least one storage cell to the storage case, wherein the storage case includes a first main wall and a second main wall that are arranged in a vertical direction, the adhesive layer adheres the at least one storage cell to the first main wall, the at least one storage cell including a first portion located on the outer peripheral edge side of the first main wall and a second portion located closer to the center of the first main wall than the first portion, the adhesive layer including a first adhesive portion that fixes the first portion to the first main wall and a second adhesive portion that fixes the second portion to the first main wall, and the thickness of the first adhesive portion is greater than the thickness of the second adhesive portion.

Images