Electricity storage device and method for manufacturing electricity storage device

Abstract

The present disclosure provides a power storage device capable of suppressing expansion of a power storage module regardless of fluctuations in the length of the power storage module, and a method for manufacturing the power storage device. The power storage device includes a power storage module including a plurality of power storage cells, a housing case including a pair of side walls, and a gasket disposed between at least one of the pair of side walls and the power storage module, the power storage module including an opposing portion opposing at least one of the pair of side walls, the gasket includes a first member having elasticity and a second member having a higher elastic modulus than the first member, the first member includes a first wire portion continuously extending so as to form a holding region capable of holding the second member, the second member is filled in the holding region, and the first member and the second member are sandwiched between at least one of the pair of side walls and the opposing portion.

Description

Technical Field

[0001] The present disclosure relates to a power storage device and a method for manufacturing the power storage device. Background Art

[0002] In the past, Japanese Patent Gazette No. 2022-153540 disclosed a battery pack (power storage device) that stores a battery array in a tray (storage shell), the tray having a pair of side beams (side walls) opposite to each other along the long side direction of a battery array (power storage module) formed by arranging multiple single cells, and elastic devices are respectively arranged between the pair of side beams and the battery array.

[0003] The elastic device is mounted on the side beams so that the mounting distance from each side beam can be changed. By changing the mounting distance, the number of cells arranged between the pair of side beams can be adjusted without changing the pitch between the pair of side beams. Summary of the invention

[0004] However, in the solution of Japanese Patent Application Publication No. 2022-153540, when the length of the battery array fluctuates due to the manufacturing tolerance of the single battery, the installation distance of the elastic device changes according to the fluctuation, thereby reducing the assembly efficiency of the battery pack and the manufacturing efficiency.

[0005] On the other hand, if the mounting distance is not changed according to the fluctuation, a gap is formed between the battery array and the tray, thereby causing the battery array to expand and deform due to heat and the like, thereby deteriorating the battery array.

[0006] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide an electricity storage device and a method for manufacturing the electricity storage device capable of suppressing expansion of an electricity storage module regardless of fluctuation in length of the electricity storage module.

[0007] The power storage device based on the present disclosure comprises: a power storage module including a plurality of power storage units arranged in a first direction; a storage case for storing the power storage module; and a gasket arranged between the power storage module and the storage case. The storage case includes a pair of side walls opposite to each other in the first direction. The gasket is arranged between at least one of the pair of side walls and the power storage module. The power storage module includes an opposing portion opposite to at least one of the pair of side walls in the first direction. The gasket includes: a first member having elasticity, and a second member having an elastic modulus higher than that of the first member. The first member includes a first line portion, and the first line portion extends continuously in a manner to form a holding area capable of holding the second member. The second member is filled in the holding area.

[0008] The first member and the second member are sandwiched between at least one of the pair of side walls and the facing portion.

[0009] According to the above configuration, in a state where the second member is filled in the holding area divided by the first line portion of the elastic first member, the first member and the second member are sandwiched by the side wall of the storage case and the opposite portion of the storage module. In this way, by filling the second member in the holding area, even if there is a fluctuation in the length of the storage module along the first direction, the gap between the storage case, the side wall and the opposite portion of the storage module can be reliably filled in the holding area. As a result, the expansion of the storage module can be suppressed, and the degradation of the storage module can be suppressed.

[0010] In the power storage device according to the present disclosure, the housing case may include a bottom wall portion that supports the power storage module. The first line portion may include a U-shape that opens to a side opposite to a side where the bottom wall portion is located.

[0011] According to the above configuration, the second member can be more reliably held inside the first member. Thus, it is possible to suppress the formation of a gap between the side wall of the storage case and the facing portion of the power storage module in the holding region.

[0012] In the power storage device based on the present disclosure, the first wire portion may have a pair of ends separated from each other on the side opposite to the side where the bottom wall portion is located. The first member may have a second wire portion extending from the end side of one of the pair of ends to the end side of the other of the pair of ends.

[0013] According to the above configuration, the second member can be more reliably held in the holding region by providing the second line portion, thereby preventing a gap from being formed between the side wall of the storage case and the facing portion of the power storage module in the holding region.

[0014] In the power storage device based on the present disclosure, the first line portion may include a pair of first extension portions, a second extension portion, and a corner portion, wherein the pair of first extension portions are arranged at intervals in the second direction and extend in a direction perpendicular to the bottom wall portion, the second direction is orthogonal to the first direction and the direction perpendicular to the bottom wall portion, the second extension portion extends in the second direction on a side closer to the bottom wall portion than the pair of first extension portions, and the corner portion connects the ends of the pair of first extension portions located on the side of the bottom wall portion to the second extension portion. The corner portion may include an inner curved portion and an outer curved portion, wherein the inner curved portion constitutes a portion of the inner edge portion of the U-shape, and the outer curved portion constitutes a portion of the outer edge portion of the U-shape.

[0015] According to the above configuration, the corner has the inner curved portion and the outer curved portion, so that the shape of the first member can be stabilized. In addition, since the second member is filled into the holding area along the inner curved portion, the formation of a gap near the corner can be suppressed.

[0016] In the power storage device according to the present disclosure, the inner curved portion may have a radius of curvature greater than a radius of curvature of the outer curved portion.

[0017] According to the above configuration, the shape of the corner portion becomes larger, and the shape of the first member can be further stabilized. Thus, the second member can be further suppressed from leaking out of the holding region.

[0018] In the power storage device according to the present disclosure, the second member may include a portion continuously along an inner edge portion of the first line portion.

[0019] According to the above configuration, the first member can suppress the displacement of the second member in a direction perpendicular to the first direction. Thus, the displacement of the second member in the first direction can be reduced, and expansion of the power storage module can be appropriately suppressed.

[0020] The manufacturing method of the power storage device based on the present disclosure comprises: a step of preparing a shell member, the shell member including a pair of side walls opposite to each other in a first direction and a bottom wall portion connected to the pair of side walls; a step of arranging a power storage module on the bottom wall portion, the power storage module including a plurality of power storage units arranged in the first direction; and a step of providing a gasket for suppressing the expansion of the power storage module between at least one of the pair of side walls and the power storage module. The step of providing the gasket includes: a step of providing a first member having elasticity, and a step of providing a second member having a higher elastic modulus than the first member. The step of providing the first member includes a step of expanding the first member that is expandably provided at a relative portion of the power storage module that is opposite to at least one of the pair of side walls in the first direction. In the step of expanding the first member, the first member is expanded in such a manner that a holding region capable of holding the second member in a fluid state is formed. The step of providing the second member includes: a step of filling the holding area with the second member in a fluid state, and a step of solidifying the second member in a fluid state. The first member and the second member are formed in a manner of being sandwiched by at least one of the pair of side walls and the opposing portion.

[0021] According to the above configuration, by expanding the first member, the first member and the side wall of the housing member can be brought into contact. In this state, the second member in a fluid state is filled in the retaining area formed (divided) by the expanded first member, and the second member in the fluid state is solidified, thereby, in the retaining area, the gap between the opposite part of the power storage module and the side wall of the storage case can be filled with the second member. Thus, even if there is a fluctuation in the length of the power storage module along the first direction, the gap between the storage case, the side wall and the opposite part of the power storage module can be reliably filled in the retaining area. As a result, the expansion of the power storage module can be suppressed, and the degradation of the power storage module can be suppressed.

[0022] In the method for manufacturing an electric storage device based on the present disclosure, the first member may be provided on the facing portion so as to include a first line portion of a U shape, the U shape opening to a side opposite to a side where the bottom wall portion is located.

[0023] According to the above configuration, the second member in a fluid state can be prevented from leaking out of the holding region, and the second member can be more reliably held inside the first member. Thus, a gap can be prevented from forming between the side wall of the storage case and the facing portion of the storage module in the holding region.

[0024] In the manufacturing method of the power storage device based on the above-mentioned present disclosure, the above-mentioned first component can also be formed in a manner having the above-mentioned first line portion and the second line portion of the above-mentioned U-shape, and the above-mentioned first line portion of the U-shape has a pair of end portions located at positions separated from each other on the opposite side of the side where the above-mentioned bottom wall portion is located, and the above-mentioned second line portion extends from the end side of one of the above-mentioned pair of end portions to the end side of the other of the above-mentioned pair of end portions.

[0025] According to the above configuration, by providing the second line portion, it is possible to further suppress the second member in a fluid state from leaking out of the holding area. Thus, the second member can be more securely held in the holding area, and as a result, it is possible to suppress the formation of a gap between the side wall of the storage case and the opposing portion of the battery module in the holding area.

[0026] In the method for manufacturing a power storage device based on the present disclosure, the first line portion may be provided in a manner including a pair of first extension portions, a second extension portion, and a corner portion, wherein the pair of first extension portions are arranged in a spaced relationship in a second direction and extend in a direction perpendicular to the bottom wall portion, the second direction being orthogonal to the first direction and the direction perpendicular to the bottom wall portion, the second extension portion extends in the second direction on a side closer to the bottom wall portion than the pair of first extension portions, and the corner portion connects the ends of the pair of first extension portions located on the side of the bottom wall portion to the second extension portion. The corner portion may be provided in a manner including an inner curved portion and an outer curved portion, the inner curved portion constituting a portion of an inner edge portion of the U-shape, and the outer curved portion constituting a portion of an outer edge portion of the U-shape.

[0027] According to the above-mentioned configuration, when the first component is expanded, the force acting on the corner can be made roughly uniform, and the first component can be expanded roughly uniformly. As a result, it is possible to prevent the formation of a local insufficiently expanded portion on the first component, and the shape of the first component can be stabilized. Therefore, it is possible to suppress the second component in a fluid state from leaking out of the retaining area, and the second component can be more effectively retained on the inner side of the first component. In addition, since the second component in a fluid state is filled into the retaining area in a manner along the inner curved portion, it is possible to suppress the formation of a gap near the corner. As a result, it is possible to suppress the formation of a gap between the side wall of the storage case and the opposing portion of the battery module in the retaining area.

[0028] In the method for manufacturing a power storage device based on the present disclosure, the radius of curvature of the inner curved portion may be larger than the radius of curvature of the outer curved portion.

[0029] According to the above configuration, the shape of the corner portion becomes larger, and the shape of the first member can be made more stable. As a result, the second member in a fluid state can be further prevented from leaking out of the holding area. As a result, the formation of a gap between the side wall of the storage case and the opposite part of the storage module in the holding area can be prevented.

[0030] In the method for manufacturing a power storage device based on the present disclosure, in the step of preparing the case member, the case member may be provided with a through hole, the through hole penetrating in a portion of at least one of the pair of side walls that is opposite to the holding region in the first direction. In the step of filling the second member having fluidity, the second member having fluidity may be injected into the holding region through the through hole.

[0031] According to the above configuration, the injectability of the second member in a state having fluidity can be improved.

[0032] In the manufacturing method of the power storage device based on the present disclosure, the step of arranging the power storage module on the bottom wall may include: applying an adhesive to at least a portion of the opposite surface of the power storage module to be opposite to the bottom wall, and pressing the power storage module relative to the bottom wall via the adhesive. In the step of expanding the first member, the first member may be expanded in a manner that separates from the adhesive.

[0033] According to the above configuration, it is possible to prevent the adhesive from adhering to the first member and hindering expansion of the first member.

[0034] In the method for manufacturing an electric storage device based on the present disclosure, the first member may be located at a predetermined distance from the bottom wall before the first member is expanded. The predetermined distance may be greater than or equal to 0.8% and less than or equal to 8% of the height of the electric storage unit in a direction perpendicular to the bottom wall.

[0035] According to the above configuration, it is possible to prevent the first member and the adhesive from coming into contact with each other. This prevents the adhesive from adhering to the first member and hindering the expansion of the first member.

[0036] In the manufacturing method of the power storage device based on the present disclosure, in the step of arranging the power storage module on the bottom wall, the first member may be arranged on the opposite portion of the power storage module in a state sealed by a sealing member at a pressure lower than atmospheric pressure. In the step of expanding the first member, the first member may be expanded by forming an opening in the sealing member.

[0037] According to the above configuration, when the power storage module is arranged on the bottom wall, the elastic first member sealed under low air pressure maintains a state of being compressed by the atmospheric pressure. Therefore, it is possible to suppress interference between the side wall and the first member, and the power storage module can be easily arranged on the bottom wall. In addition, by providing an opening on the sealing member, the first member can be easily expanded. Since the holding area is formed by making the expanded first member closely contact with the side wall, when the second member in a fluid state is injected into the holding area, it is possible to suppress the second member in a fluid state from overflowing from the holding area.

[0038] The above and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic plan view of the power storage device according to the embodiment.

[0040] Figure 2 It is a perspective view showing the structure of the periphery of the facing portion of the power storage module in the power storage device according to the embodiment.

[0041] Figure 3 It is a diagram showing the structure near the corner portion of the first member according to the embodiment.

[0042] Figure 4 It is a diagram showing a modified example of the corner portion of the first member.

[0043] Figure 5 1 is a flowchart showing a process for manufacturing the power storage device according to the embodiment.

[0044] Figure 6 It means in Figure 5 FIG. 1 is a diagram showing a step of applying an adhesive in the process of manufacturing an electricity storage device.

[0045] Figure 7 It means in Figure 5 FIG. 1 is a diagram showing a step of pressing the power storage module relative to the bottom wall portion in the manufacturing process of the power storage device.

[0046] Figure 8 It means in Figure 5 FIG. 1 is a diagram showing a step of expanding the first member in the manufacturing process of the power storage device.

[0047] Fig. 9 It means in Figure 5 FIG. 1 is a diagram showing a step of filling the second member in a fluid state in the manufacturing process of the power storage device.

[0048] Fig.10 It means in Figure 5 The diagram shows a state after the step of solidifying the second member in a fluid state in the manufacturing process of the power storage device shown. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and their description will not be repeated.

[0050] (Electricity storage device)

[0051] Figure 1 is a schematic plan view of an electric storage device according to an embodiment. Figure 1 In the figure, for the sake of convenience, the upper shell in the storage shell is omitted. Figure 2 1 is a perspective view showing the structure of the surrounding area of ​​the facing portion of the power storage module in the power storage device according to the embodiment. Figure 2 In the figure, for convenience, the storage housing is shown by a single dotted line. Figure 1 and Figure 2 , a power storage device 1 according to an embodiment will be described.

[0052] The power storage device 1 of the embodiment is mounted on, for example, a hybrid vehicle that can run using power from at least one of an electric motor and an engine, or an electric vehicle that runs using a driving force obtained from electric energy. The power storage device 1 is installed below the floor of the vehicle. The installation position of the power storage device 1 in the vehicle is not limited to the above position, and it may be arranged, for example, between the floor and the seat.

[0053] like Figure 1 As shown, the power storage device 1 includes a housing case 10 , a plurality of power storage modules 20 , a plurality of gaskets 30 , and an electronic device 50 .

[0054] The housing case 10 houses a plurality of power storage modules 20 and a plurality of gaskets 30. The housing case 10 includes an upper case 11 (see FIG. 1 ) facing each other in the vertical direction. Figure 2 ) and the lower housing 12. The up-down direction is perpendicular to the first direction (DR1 direction) described later and is perpendicular to the bottom wall portion 125 of the lower housing 12 (see Figure 2 ) in the vertical direction.

[0055] The lower case 12 has a substantially box-like shape that is open upward. The lower case 12 is formed of a metal material such as an aluminum alloy. The lower case 12 has a bottom wall portion 125 (see Figure 2 ), a pair of side walls 121 , 122 , a first wall portion 123 and a second wall portion 124 .

[0056] The pair of side walls 121 and 122 are opposite to each other in a first direction. The first direction is, for example, a direction parallel to the width direction of the vehicle when the power storage device 1 is mounted on the vehicle. The first wall portion 123 and the second wall portion 124 are opposite to each other in a second direction (DR2 direction). The second direction is a direction orthogonal to the first direction and the up-down direction. The second direction is, for example, a direction parallel to the front-back direction of the vehicle in the above-mentioned mounting state.

[0057] The pair of side walls 121 and 122 , the first wall portion 123 , and the second wall portion 124 are connected to the peripheral edge of the bottom wall portion 125 , and constitute a peripheral wall portion of the lower case 12 .

[0058] The upper case 11 is provided to cover the opening of the lower case 12 which opens upward. The upper case 11 may be formed of a metal material such as an aluminum alloy, or may be formed of a resin, etc. When the upper case 11 is formed of a resin, the storage case 10 can be made lighter.

[0059] A plurality of partition members 40 are provided inside the storage case 10. The plurality of partition members 40 extend along the first direction, respectively. The plurality of partition members 40 are arranged at intervals in the second direction to partition the area where the power storage module 20 is arranged. Furthermore, a support member for supporting the upper case may be provided on the partition member 40.

[0060] The plurality of power storage modules 20 are arranged in the storage case 10 in the partitioned regions partitioned by the partitioning member 40. The power storage modules 20 are bonded to each other by, for example, a thermally conductive adhesive 70 (see Figure 7 ) is fixed to the bottom wall portion 125.

[0061] The plurality of power storage modules 20 are arranged in a row at intervals in the second direction. A partition member 40 is arranged in the gap between the adjacent power storage modules 20. In the present embodiment, an example is given of two power storage modules 20 arranged in parallel in the second direction, but the number of the power storage modules 20 may be a single one or three or more.

[0062] The plurality of power storage modules 20 include a plurality of power storage cells 21 arranged in a first direction. The power storage cells 21 are secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries. The power storage cells 21 have a rectangular shape, for example. The secondary battery may use a liquid electrolyte or a solid electrolyte.

[0063] The power storage module 20 has facing portions 20a and 20b facing the pair of side walls 121 and 122 in the first direction. The facing portion 20a (first facing portion) faces the side wall 121 , and the facing portion 20b (second facing portion) faces the side wall 122 .

[0064] The plurality of power storage modules 20 may include a pair of end plates or a plurality of spacers, insulating films, and the facing portions 20 a and 20 b may be formed by members located at both ends of the power storage module 20 in the first direction.

[0065] The electronic device 50 is disposed on one side in the second direction in the housing case 20. The electronic device 50 may include, for example, a battery ECU and a BMS (battery management system). The one side in the second direction refers to the front side of the vehicle in the above-mentioned mounted state.

[0066] The gasket 30 is disposed in the gap between the power storage module 20 and the storage case 10. The gasket 30 suppresses, for example, expansion of the power storage module 20. In the present embodiment, two gaskets 30 are disposed in the gap between each power storage module 20 and the storage case 10.

[0067] Specifically, the gasket 30 is disposed in the gap between the side wall 121 and the facing portion 20 a , and the gasket 30 is disposed in the gap between the side wall 122 and the facing portion 20 b .

[0068] The gasket 30 includes a first member 31 and a second member 32. The first member 31 has elasticity. The first member 31 is composed of a foaming member such as sponge, for example. The elastic modulus of the second member 32 is higher than that of the first member 32. The second member 32 can be, for example, an adhesive layer formed by curing a resin member such as phenol and polyurethane, or an adhesive such as a polyurethane adhesive and a silicone adhesive. As the adhesive, an adhesive that cures at room temperature can be used. In this case, the thermal influence on the storage module 20 can be reduced, so the expansion of the storage module 20 can be suppressed.

[0069] The first member 31 and the second member 32 are sandwiched between the side wall 121 and the facing portion 20a on one side in the first direction. In addition, the first member 31 and the second member 32 are sandwiched between the side wall 122 and the facing portion 20b on the other side in the first direction.

[0070] like Figure 2 As shown, the first member 31 includes a first line portion 33 and a second line portion 34. The first line portion 33 forms a holding region R (see FIG. 1 ) capable of holding the second member 32. Figure 8 ) in a manner that extends continuously.

[0071] Specifically, the first wire portion 33 has a U-shape opened upward. Thus, the second member 32 can be held by suppressing downward movement of the second member 32 inside the first wire portion 33. The first wire portion 33 is provided along the peripheral edge of the facing portions 20a, 20b.

[0072] The first line portion 33 includes a pair of first extension portions 331, a second extension portion 332, and a corner portion 333. The pair of first extension portions 331 are arranged in a spaced relationship in the second direction and extend in a direction perpendicular to the bottom wall portion 125. The second extension portion 332 extends in the second direction on the bottom wall portion 125 side relative to the pair of first extension portions 331. The corner portion 333 connects the respective ends of the pair of first extension portions 331 located on the bottom wall portion 125 side and the second extension portion 332.

[0073] The first line portion 33 has a pair of end portions 33a and 33b, and the pair of end portions 33a and 33b are separated from each other on the side opposite to the side where the bottom wall portion 125 is located. The first line portion 33 is covered by a sealing member 61 having an opening 61c. The opening 61c is provided at a position corresponding to the pair of end portions 33a and 33b. Air enters the sealing member 61 from the opening 61c.

[0074] The second wire portion 34 extends from one end 33a of the pair of end portions 33a and 33b to the other end 33b. The second wire portion 34 extends along the second direction. The second wire portion 34 is arranged away from the pair of first extension portions 331, and a gap is formed between the second wire portion 34 and the pair of first extension portions 331. Furthermore, the second wire portion 34 may be omitted. In addition, when viewed from the first direction, the upper end of the second wire portion 34 may be located on the opposite side of the bottom wall portion 125 and protrude upward from the side of the storage cell 21 extending in the long side direction (second direction). In this case, the input of the load to the upper surface of the storage module 20 can be suppressed. Furthermore, when viewed from the first direction, the upper end of the second wire portion 34 may be located at the same height as the side of the storage cell 21 located on the opposite side of the bottom wall portion 125 and extending in the long side direction (second direction), or may be located below the side.

[0075] The second member 32 is filled in the holding region R formed by the first line portion 33. The holding region R is a space surrounded by the first line portion 33 and located between the side wall 121 and the opposite portion 20a on one side in the first direction, and is a space surrounded by the first line portion 33 and located between the side wall 122 and the opposite portion 20b on the other side in the first direction. Furthermore, the holding region R is not limited to the above-mentioned region, and may be a region having an appropriate shape capable of holding the second member 32 in the central portion of the long side direction (second direction) facing the storage cell 21 as viewed from the first direction. In addition, the holding region R may be a region having an appropriate shape capable of holding the second member 32 in the central portion of the short side direction (up and down direction) facing the storage cell 21 as viewed from the first direction. The first line portion 33 may have an appropriate shape corresponding to the holding region R having an appropriate shape. The second member 32 includes a portion that is continuously along the inner edge of the first line portion 33.

[0076] The second line portion 34 is covered by a sealing member 62 having an opening 62c. The opening 62c is provided so as to extend in the second direction on the upper end side of the sealing member 62. Air enters the sealing member 62 through the opening 62c.

[0077] Figure 3 1 is a diagram showing a structure near a corner of the first member of the embodiment. Figure 3 As shown, the corner portion 333 has an inner curved portion 334 constituting a part of the inner edge of the U shape, and an outer curved portion 335 constituting a part of the outer edge of the U shape. In the embodiment, the curvature radius of the inner curved portion 334 is substantially the same as the curvature radius of the outer curved portion 335.

[0078] Figure 4 FIG. 2 is a diagram showing a deformation example of the corner portion of the first member. Figure 4As shown, in the corner portion 333 , the curvature radius of the inner curved portion 334 is larger than the curvature radius of the outer curved portion 335 .

[0079] As described above, in the power storage device 1 of the present embodiment, in a state where the second member 32 is filled in the holding region R defined by the first line portion 33 of the first member 31 having elasticity, the first member 31 and the second member 32 are sandwiched by the side walls 121, 122 of the storage case 10 and the facing portions 20a, 20b of the power storage module 20. By filling the holding region R with the second member 32, even when there is a fluctuation in the length of the power storage module 20 along the first direction, the gap between the side walls 121, 122 of the storage case 10 and the facing portions 20a, 20b of the power storage module 20 can be reliably filled in the holding region R. As a result, expansion of the power storage module 20 can be suppressed, and degradation of the power storage module 20 can be suppressed.

[0080] In addition, since the first line portion 33 has a U-shape that opens toward the side opposite to the side where the bottom wall portion 125 is located, the second member 32 can be more reliably held inside the first member 31. Thus, in the holding region R, it is possible to suppress the formation of gaps between the side walls 121, 122 and the facing portions 20a, 20b of the power storage module 20.

[0081] Furthermore, since the first member 31 has the second line portion 34 , the second member 32 can be more reliably held in the holding region R.

[0082] Furthermore, the shape of the first member 31 can be stabilized by the corner 333 of the first line portion 33 having the inner curved portion 334 and the outer curved portion 335. In addition, since the second member 32 is filled in the holding region R along the inner curved portion 334, the formation of a gap near the corner 333 can be suppressed.

[0083] When the curvature radius of the inner curved portion 334 is larger than that of the outer curved portion 335 as in the above-mentioned modification, the shape of the corner portion 333 becomes larger, and the shape of the first member 31 can be further stabilized. Thus, the second member 32 can be further prevented from leaking out of the holding region R.

[0084] Furthermore, since the second member 32 includes a portion continuously along the inner edge of the first line portion 33, the displacement of the second member 32 in a direction perpendicular to the first direction can be suppressed by the first member 31. Thus, the displacement of the second member 32 in the first direction can be reduced, and the expansion of the power storage module 20 can be appropriately suppressed.

[0085] (Manufacturing method)

[0086] Figure 51 is a flowchart showing a process for manufacturing the power storage device according to the embodiment. Figures 6 to 10 Yes means Figure 5 A diagram showing a predetermined step in the manufacturing process or a state after a predetermined step. Figures 5 to 10 , a method for manufacturing the power storage device 1 is described. Figures 6 to 10 In the figure, for convenience, one side (opposing portion 20a side) in the first direction is shown in the power storage module 20, but the same contents as the one side are also implemented on the other side in the first direction. Therefore, the contents on the one side in the first direction are described below, and the description of the state of the other side in the first direction is omitted.

[0087] like Figure 5 As shown, the manufacturing process of the power storage device 1 includes a step of preparing a case member ( S10 ), a step of arranging the power storage module 20 on the bottom wall portion 125 ( S20 ), and a step of providing the gasket 30 ( S30 ).

[0088] When manufacturing the power storage device 1, first, a case member is prepared in step (S10). Specifically, as a case member, the lower case 12 is prepared, and the lower case 12 includes a pair of side walls 121 and 122 and a bottom wall portion 125 connecting the pair of side walls 121 and 122. A through hole 121h is provided in the side wall 121. Similarly, a through hole is also provided in the side wall 122.

[0089] Next, in step (S20), the storage module 20 including the plurality of storage cells 21 arranged in the first direction is disposed on the bottom wall 125. Step (S20) includes applying an adhesive (S21) and pressing the storage module 20 against the bottom wall 125 (S22).

[0090] Figure 6 It means in Figure 5 FIG. 1 is a diagram showing a step of applying an adhesive in the manufacturing process of a power storage device. Figure 5 and Figure 6 As shown, when the step (S20) is implemented, first, in the step (S21), the adhesive 70 is applied to at least a portion of the opposing surface 20c of the power storage module 20 that is to be opposed to the bottom wall portion 125. As the adhesive 70, a thermally conductive adhesive may be used, so that the power storage module 20 can be cooled through the bottom wall portion 125.

[0091] Figure 7 It means in Figure 5 FIG. 1 is a diagram showing a step of pressing the power storage module relative to the bottom wall portion in the manufacturing process of the power storage device.

[0092] Then, if Figure 5 and Figure 7As shown, in step (S22), the storage battery module 20 is pressed relative to the bottom wall portion 125 via the adhesive 70. Specifically, the storage battery module 20 is pressed relative to the bottom wall portion 125 in a manner that the adhesive 70 is extended toward the opposite surface 20c as a whole, with the bottom wall portion 125 facing the opposite surface 20c from the upper side.

[0093] Here, the first member 31 is provided in the facing portion 20a facing the side wall 121. Specifically, the first member 31 is provided in the facing portion 20a so as to include a first line portion 33 and a second line portion 34.

[0094] The first wire portion 33 has a U-shape that opens toward the side opposite to the side where the bottom wall portion 125 is located. The second wire portion 34 extends from the end side of one of the pair of end portions of the first wire portion 33 toward the end side of the other, and the pair of end portions of the first wire portion 33 are located at positions separated from each other on the side opposite to the side where the bottom wall portion 125 is located. When viewed from the first direction, the end portion of the second wire portion 34 located on the side opposite to the side where the bottom wall portion 125 is located may protrude from the side of the storage cell 21 located on the side opposite to the bottom wall portion 125 and extending along the longitudinal direction (second direction) to the side opposite to the side where the bottom wall portion 125 is located. In this case, it is possible to suppress the input of a load to the main surface of the storage cell 20 located on the side opposite to the bottom wall portion 125. Furthermore, when viewed from the first direction, the above-mentioned end of the second line portion 34 can be located at the same height as the side of the storage unit 21 located on the opposite side of the bottom wall portion 125 and extending along the long side direction (the second direction), or can be located at a position closer to the bottom wall portion 125 than the side.

[0095] The first line portion 33 is sealed at a pressure lower than the atmospheric pressure by the sealing member 61. The second line portion 34 is sealed at a pressure lower than the atmospheric pressure by the sealing member 62. In this state, the openings 61c and 62c are not provided in the sealing members 61 and 62, and the first line portion 33 and the second line portion 34 are hermetically sealed.

[0096] Thus, the first member 31 (the first line portion 33 and the second line portion 34 ) is in a compressed state, and when the power storage module 20 is arranged on the bottom wall portion 125 , interference between the first member 31 and the side wall 121 can be suppressed.

[0097] The first member 31 is disposed away from the spread adhesive 70. Specifically, the first member 31 is located at a predetermined distance L from the bottom wall 125. The predetermined distance is 0.8% to 8% of the height h of the power storage cell 21 in the direction perpendicular to the bottom wall 125.

[0098] By setting such a positional relationship, it is possible to prevent the spread adhesive 70 from coming into contact with the first member 31. Thus, it is possible to prevent the adhesive 70 from adhering to the first member 31 and hindering the expansion of the first member 31 in the step (S41) described later.

[0099] Then, if Figure 5 As shown, a step ( S30 ) is performed to provide a gasket 30 between the side wall 121 and the power storage module 20 for suppressing expansion of the power storage module 20 .

[0100] The step ( S30 ) includes a step ( S40 ) of providing a first member and a step ( S50 ) of providing a second member.

[0101] When the step (S30) is performed, the step (S40) is performed first to provide a first member having elasticity. The step (S40) includes a step (S41) of expanding the first member.

[0102] Figure 8 It means in Figure 5 FIG. 1 is a diagram showing a step of expanding the first member in the manufacturing process of the power storage device.

[0103] like Figure 5 and Figure 8 As shown, in step (S41), the first member 31 provided in an expandable manner on the opposing portion 20a of the power storage module 20 opposing the side wall 121 is expanded. Specifically, the opening 61c (see Figure 2 ), 62c to expand the first member 31. The openings 61c, 62c are formed by partially cutting the sealing members 61, 62 with a cutting member.

[0104] As described above, the first line portion 33 and the second line portion 34 are sealed at low pressure, and thus maintain a state of being compressed by the surrounding atmospheric pressure. By providing openings 61c and 62c in the sealing members 61 and 62, air enters the sealing members 61 and 62, and the first line portion 33 and the second line portion 34 can be easily expanded.

[0105] At this time, the first line portion 33 and the second line portion 34 are expanded so as to be separated from the adhesive 70. This can prevent the adhesive 70 from being attached to the first member 31 and hindering the expansion of the first member 31.

[0106] In the step (S41), the first member 31 is expanded to form a holding region R, and the holding region R can hold the second member 90 (see Fig. 9) is maintained. The second member 90 in a fluid state is a liquid member such as a liquid resin member or a liquid adhesive. The first member 31 is expanded in a manner capable of storing the liquid member. As described above, for example, the first member 31 includes a first U-shaped first line portion 33 extending continuously, and the first line portion 33 is expanded to be closely attached to the side wall 121, thereby enabling the liquid member to be stored in the space inside the expanded first line portion 33.

[0107] In the embodiment, the case where the first line portion 33 has a U-shape is exemplified, but the first line portion 33 may have other shapes as long as it can form a space capable of storing the liquid member in close contact with the side wall 121 .

[0108] When the first line portion 33 is formed in a U-shape along the peripheral edge of the facing portion 20a, the space (retaining region R) inside the first line portion 33 can be widened. Thus, by filling the retaining region R with the second member, expansion of the power storage module 20 can be effectively suppressed.

[0109] In addition, by also expanding the second wire portion 34, when the second member 90 in a fluid state is injected into the holding region R, the second member 90 in a fluid state can be suppressed from leaking out of the holding region R. Furthermore, the second wire portion 34 is provided so as to form a gap between a pair of end portions of the first wire portion 33 at a position separated from each other on the side opposite to the side where the bottom wall portion 125 is located. Therefore, when the second member 90 in a fluid state is injected into the holding region R, air can be discharged from the gap.

[0110] Furthermore, as described above, the first line portion 33 has the corner portion 333, and the corner portion 333 has the inner curved portion 334 and the outer curved portion 335. Therefore, when the first line portion 33 is expanded, a force can be applied to the corner portion 333 more evenly than to the unbent corner portion, and the first line portion 33 can be expanded evenly. Thus, it is possible to suppress the expansion of a part of the corner portion 333 from being partially insufficient. As a result, it is possible to suppress the formation of a gap between the part where the expansion is insufficient and the side wall 121, and it is possible to suppress the second member in a fluid state from leaking from the gap to the bottom wall portion 125 side.

[0111] The radius of curvature of the inner curved portion 334 may be larger than the radius of curvature of the outer curved portion 335. In this case, the shape of the corner portion 333 can be enlarged, and it is possible to suppress the force from acting locally on the corner portion 333 during expansion. Thus, the shape of the first line portion 33 can be stabilized. In addition, by making the shape of the corner portion 333 larger and more stable, the close fit with the side wall 121 can be improved at the corner portion 333.

[0112] Then, if Figure 5As shown, a step (S50) is performed to provide the second member 32. The step (S50) includes a step (S51) of filling the second member 90 in a fluid state, and a step (S52) of solidifying the second member 90 in a fluid state.

[0113] Fig. 9 It means in Figure 5 FIG. 1 is a diagram showing a step of filling the second member 90 in a fluid state in the manufacturing process of the power storage device shown in FIG. Figure 5 and Fig. 9 As shown, when the step (S50) is implemented, first, in the step (S51), the second member 90 in a fluid state is injected into the holding area R. Specifically, the second member 90 in a fluid state is injected into the holding area R through the through hole 121h that penetrates along the first direction in the portion of the side wall 121 opposite to the holding area R. More specifically, the pipe 81 is inserted into the through hole 121h, and the second member 90 in a fluid state is made to flow in the pipe 81 and injected into the holding area R. When the second member 90 in a fluid state is filled in the holding area R, the injection of the second member 90 in a fluid state is stopped. After the injection is completed, the pipe 81 is pulled out from the through hole 121h.

[0114] Then, if Figure 5 As shown, in step ( S52 ), the second member 90 in a fluid state is solidified. Fig.10 It means in Figure 5 FIG. 1 is a diagram showing a state after the step of solidifying the second member 90 in a fluid state in the manufacturing process of the power storage device shown in FIG. Fig.10 As shown, when the second member 90 in a fluid state is a member that solidifies at room temperature, the second member 90 in a fluid state is solidified to form the second member 32 by being left at room temperature for a predetermined time. The elastic modulus of the second member 32 is higher than that of the first member 31, and the second member 32 is formed over a wide range in a manner that fills the gap between the side wall 121 and the opposing portion 20a. Thus, the expansion of the power storage module 20 can be effectively suppressed.

[0115] Furthermore, the second member 90 in a fluid state may be thermosetting or photocurable. In this case, heating or light irradiation may be performed to cure the second member 90 in a fluid state.

[0116] Next, the opening of the lower case 12 is covered with the upper case 11. Through the above steps, the power storage device 1 of the embodiment can be manufactured.

[0117] (Other Modifications)

[0118] In the above embodiment, the case where the gasket 30 is provided between the pair of side walls 121, 122 and the power storage module 20 is illustrated, but the present invention is not limited thereto. The gasket 30 only needs to be provided between at least one of the pair of side walls 121, 122 and the power storage module 20. In this case, the power storage device is also manufactured according to the above manufacturing method.

[0119] In the above embodiment, the case where the through holes are provided in the pair of side walls 121 and 122, and the second member in a fluid state is injected into the holding region R through the through holes in the step (S51), but the present invention is not limited thereto. In the case where the through holes are not provided in the pair of side walls 121 and 122, the second member in a fluid state may be injected from the gap between the pair of end portions 33a and 33b of the first line portion 33 and the second line portion 34.

[0120] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power storage device comprising: A power storage module including a plurality of power storage cells arranged in a first direction; a housing for housing the power storage module; and a gasket disposed between the power storage module and the housing case, The storage housing includes a pair of side walls that are opposite to each other in the first direction. The gasket is arranged between at least one of the pair of side walls and the power storage module. The power storage module includes an opposing portion opposing at least one of the pair of side walls in the first direction. The gasket includes: a first member having elasticity, and a second member having a higher elastic modulus than the first member. The first member includes a first line portion, and the first line portion extends continuously so as to form a holding region capable of holding the second member. The second member is filled in the holding area, The first member and the second member are sandwiched between at least one of the pair of side walls and the facing portion.

2. The power storage device according to claim 1, The storage case has a bottom wall portion that supports the power storage module. The first line portion has a U-shape that opens toward a side opposite to a side where the bottom wall portion is located.

3. The power storage device according to claim 2, The first line portion has a pair of end portions spaced apart from each other on the side opposite to the side where the bottom wall portion is located. The first member includes a second line portion extending from an end side of one of the pair of end portions toward an end side of the other of the pair of end portions.

4. The power storage device according to claim 2, wherein the first line portion includes a pair of first extending portions, a second extending portion, and a corner portion. The pair of first extension portions are arranged at intervals in a second direction and extend in a direction perpendicular to the bottom wall portion, the second direction is orthogonal to the first direction and the direction perpendicular to the bottom wall portion, the second extension portion extends in the second direction on a side closer to the bottom wall portion than the pair of first extension portions, and the corner portion connects the respective ends of the pair of first extension portions located on the bottom wall portion side and the second extension portion, The corner portion includes an inner curved portion and an outer curved portion, the inner curved portion constituting a portion of an inner edge portion of the U shape, and the outer curved portion constituting a portion of an outer edge portion of the U shape. 5 . The power storage device according to claim 4 , wherein a curvature radius of the inner curved portion is larger than a curvature radius of the outer curved portion. 6 . The power storage device according to claim 1 , wherein the second member includes a portion continuously along an inner edge portion of the first line portion.

7. A method for manufacturing an electric storage device, comprising: a step of preparing a housing member including a pair of side walls opposing each other in a first direction and a bottom wall portion connecting the pair of side walls; a step of arranging a power storage module on the bottom wall portion, the power storage module including a plurality of power storage cells arranged in the first direction; and a step of providing a gasket for suppressing expansion of the power storage module between at least one of the pair of side walls and the power storage module, The step of providing the gasket includes: providing a first member having elasticity, and providing a second member having a higher elastic modulus than the first member. The step of providing the first member includes the step of expanding the first member provided in an expandable manner at a portion of the power storage module that faces at least one of the pair of side walls in the first direction. In the step of expanding the first member, the first member is expanded so as to form a holding region capable of holding the second member in a fluid state. The step of providing the second member includes: a step of filling the holding region with the second member in a fluid state, and a step of solidifying the second member in a fluid state. The first member and the second member are formed so as to be sandwiched between at least one of the pair of side walls and the facing portion.

8. The method for manufacturing an electric storage device according to claim 7, The first member is provided at the facing portion so as to include a first line portion of a U shape, and the U shape is open to a side opposite to a side where the bottom wall portion is located.

9. The method for manufacturing an electric storage device according to claim 8, The first component is formed in a manner having the first line portion and the second line portion of the U-shape, wherein the first line portion of the U-shape has a pair of end portions located at positions separated from each other on the opposite side to the side where the bottom wall portion is located, and the second line portion extends from the end side of one of the pair of end portions to the end side of the other of the pair of end portions.

10. The method for manufacturing an electric storage device according to claim 8, The first line portion is provided in a manner of having a pair of first extension portions, a second extension portion, and a corner portion, The pair of first extension portions are arranged at intervals in a second direction and extend in a direction perpendicular to the bottom wall portion, the second direction is orthogonal to the first direction and the direction perpendicular to the bottom wall portion, the second extension portion extends in the second direction on a side closer to the bottom wall portion than the pair of first extension portions, and the corner portion connects the respective ends of the pair of first extension portions located on the bottom wall portion side and the second extension portion, The corner portion is provided so as to have an inner curved portion and an outer curved portion, the inner curved portion constituting a portion of an inner edge portion of the U-shape, and the outer curved portion constituting a portion of an outer edge portion of the U-shape. 11 . The method for manufacturing an electric storage device according to claim 10 , wherein a radius of curvature of the inner curved portion is larger than a radius of curvature of the outer curved portion.

12. The method for manufacturing an electric storage device according to any one of claims 7 to 11, In the step of preparing the shell member, the shell member is provided with a through hole, wherein the through hole penetrates along the first direction at a portion of at least one of the pair of side walls that faces the holding area. In the step of filling the second member in a state having fluidity, the second member in a state having fluidity is injected into the holding region through the through hole.

13. The method for manufacturing an electric storage device according to any one of claims 7 to 11, The step of arranging the power storage module on the bottom wall portion includes: applying an adhesive to at least a portion of a surface of the power storage module that is to be opposed to the bottom wall portion; and pressing the power storage module relative to the bottom wall portion via the adhesive. In the step of expanding the first member, the first member is expanded so as to be separated from the adhesive.

14. The method for manufacturing an electric storage device according to claim 13, In a state before the first member is expanded, the first member is located at a position away from the bottom wall by a predetermined distance. The predetermined distance is not less than 0.8% and not more than 8% of the height of the power storage unit in a direction perpendicular to the bottom wall portion.

15. The method for manufacturing an electric storage device according to any one of claims 7 to 11, In the step of arranging the power storage module on the bottom wall portion, the first member is provided on the facing portion of the power storage module in a state of being sealed by a sealing member at a gas pressure lower than atmospheric pressure. In the step of expanding the first member, the first member is expanded by forming an opening in the sealing member.

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