Power storage pack

Abstract

To provide a power storage pack which can prevent mixing of different types of adhesives.SOLUTION: A power storage pack 500 disclosed here includes: a plurality of power storage devices 100 arranged along a predetermined arrangement direction; side frames 220 disposed at ends in the arrangement direction; and a cover 210 which is disposed so as to cover at least parts of the power storage devices 100 and the side frames 220. The power storage pack 500 has: plate-like partition walls 350 each disposed between the side frame 220 and the power storage devices 100 and having a contact point 352 which is in contact with the cover 210; a first adhesive 410 disposed on surfaces of the power storage devices 100 and the cover 210 which face each other; and a second adhesive 420 disposed in an area 200b where the side frame 220, the partition wall 350, and the cover 210 face each other and which is isolated from the first adhesive 410.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electricity storage pack. [Background technology]

[0002] Conventionally, power storage packs equipped with multiple power storage devices have been widely used in vehicle drive power sources and the like to achieve high output. As a related technique, Patent Document 1 discloses a battery pack (power storage pack) equipped with a housing (casing) and multiple electric cells (power storage devices) mounted within the housing. The housing of the battery pack is equipped with a groove for filling with adhesive and a guide tank. This is said to prevent the adhesive from spilling out to the outside, and to bond the housing to the cover and the housing to the electric cells using the adhesive guided into the tank via the groove. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Utility Model No. 217361763 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electricity storage pack, different adhesive performance is required for bonding between the electricity storage device and the housing (for example, the side frame) and for bonding the housing (for example, between the side frame and the cover). Therefore, different types of adhesives may be used for these bonds. If different types of adhesives are used here, there is a risk that the performance of each adhesive will deteriorate due to mixing of the different types of adhesives during assembly of the electricity storage pack.

[0005] In view of this, an object of the present disclosure is to provide an electricity storage pack that can prevent different types of adhesives from mixing with each other. [Means for solving the problem]

[0006] The electricity storage pack disclosed herein includes a plurality of electricity storage devices, each having a hexahedral box-shaped case, arranged along a predetermined arrangement direction, side frames arranged at ends in the arrangement direction, and a cover arranged to cover the plurality of electricity storage devices and at least a portion of the side frames. Here, the electricity storage pack includes: a plate-shaped partition wall arranged between the side frames and the electricity storage devices, the partition wall having contact points in contact with the cover, a first adhesive arranged on a surface where the electricity storage devices and the cover face each other; and a second adhesive arranged in a region where the side frames, the partition wall, and the cover face each other and which is separated from the first adhesive.

[0007] According to this configuration, by providing a partition wall having a contact point with the cover between the side frame and the power storage device, the second adhesive is disposed in an area isolated from the first adhesive. The partition wall of the above configuration also prevents the second adhesive from penetrating in the direction of the first adhesive, and similarly prevents the first adhesive from penetrating in the direction of the second adhesive. Therefore, it is possible to prevent the first adhesive and the second adhesive from mixing with each other. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view schematically showing an electricity storage pack according to one embodiment. [Figure 2] FIG. 2 is a perspective view schematically illustrating an electricity storage device according to one embodiment. [Figure 3] FIG. 3 is a schematic exploded view of a housing according to one embodiment. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view that schematically illustrates the inside of an electricity storage pack according to one embodiment. [Figure 5] FIG. 5 is a view corresponding to FIG. 4, illustrating how the bottom cover according to the embodiment is assembled. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, with reference to the drawings, several preferred embodiments of the technology disclosed herein will be described. It should be noted that matters other than those specifically mentioned in this specification that are necessary for implementing the technology disclosed herein (for example, the general configuration and manufacturing process of an electricity storage device that does not characterize the technology disclosed herein) can be understood as design matters for a person skilled in the art based on prior art in the relevant field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the relevant field. In this specification, the expression "A to B (where A and B are any numerical values)" indicating a range means "A or more and B or less," and also encompasses the meanings of "greater than A but less than B," "greater than A but B or less," and "greater than A but less than B."

[0010] In this specification, the term "electricity storage device" refers to a device that can be charged and discharged. Electricity storage devices include batteries such as primary batteries and secondary batteries (e.g., lithium-ion secondary batteries and nickel-metal hydride batteries), and capacitors (physical batteries) such as electric double-layer capacitors.

[0011] In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom. In the drawings, the symbol X indicates the short side direction of the electricity storage pack 500 and the thickness direction of the electricity storage device 100, the symbol Y indicates the long side direction of the electricity storage pack 500 perpendicular to the short side direction and the width direction of the electricity storage device 100, and the symbol Z indicates the up-down (height) direction of the electricity storage pack 500 and the electricity storage device 100. The short side direction X is also the arrangement direction of the electricity storage devices 100 and the thickness direction of the electricity storage device 100. However, these directions are merely provided for the convenience of description and do not limit the installation form of the electricity storage device 100 and the electricity storage pack 500 in any way.

[0012] FIG. 1 is a perspective view that schematically shows an electricity storage pack 500 according to one embodiment. For ease of explanation, FIG. 1 omits illustration of the internal configuration of the electricity storage pack 500 (housing 200) except for the electricity storage device 100. Similarly, for ease of explanation, FIG. 1 omits illustration of the positive electrode terminal 30 and the negative electrode terminal 40 of the electricity storage device 100. The electricity storage pack 500 includes a plurality of electricity storage devices 100, a side frame 220, and a bottom cover 210. Here, the electricity storage pack 500 further includes an end frame 230 and a top cover 240. The bottom cover 210 is an example of "a cover that is arranged to cover the electricity storage device and at least a portion of the side frame" in this specification.

[0013] The electricity storage pack 500 includes a plurality of electricity storage devices 100 arranged in a predetermined direction. Specifically, the electricity storage devices 100 are arranged so that surfaces (here, first side walls 12b) of adjacent electricity storage devices 100 in the thickness direction X face each other. That is, the plurality of electricity storage devices 100 are arranged (stacked) along the X direction. As shown in FIG. 1 , in this embodiment, the plurality of electricity storage devices 100 are arranged in a plurality of rows (three rows). However, the number of electricity storage devices 100 and the number of rows to be arranged are not limited to the embodiment disclosed in FIG. 1 and can be changed as appropriate. For example, the electricity storage devices 100 may be arranged in one row, two rows, or four or more rows. The electricity storage pack 500 according to this embodiment has a so-called cell-to-pack structure in which the plurality of electricity storage devices 100 are stored as they are without configuring an electricity storage module or the like.

[0014] Although not shown in the drawings, the plurality of power storage devices 100 may be electrically connected by a conductive member such as a bus bar. The bus bar is electrically connected to the positive terminal 30 or the negative terminal 40 of each power storage device 100. In this case, the bus bar may connect the plurality of power storage devices 100 in series, in parallel, or in a multi-series-multi-parallel configuration.

[0015] Fig. 2 is a perspective view schematically illustrating an electricity storage device 100 according to one embodiment. The electricity storage device 100 is, for example, a lithium ion secondary battery, and includes a box-shaped case 10, a positive electrode terminal 30, and a negative electrode terminal 40. The shape and size of the plurality of electricity storage devices 100 are not limited to the embodiment disclosed in Fig. 2 and can be changed as appropriate.

[0016] The box-shaped case 10 is a case that houses an electrode assembly (not shown) and a non-aqueous electrolyte (not shown). As shown in FIG. 2, the box-shaped case 10 has a flat, bottomed, hexahedral (rectangular) outer shape. The material of the box-shaped case 10 may be the same as that conventionally used, and is not particularly limited. The box-shaped case 10 is preferably made of metal, and more preferably made of, for example, aluminum, an aluminum alloy, iron, an iron alloy, or the like. As shown in FIG. 2, the box-shaped case 10 here includes an exterior body 12 having an opening 12h, and a sealing plate (lid) 14 that seals the opening 12h.

[0017] As shown in FIG. 2, the exterior body 12 includes a bottom 12a, a pair of first side walls 12b extending from the bottom 12a and facing each other, and a pair of second side walls 12c extending from the bottom 12a and facing each other. The bottom 12a is substantially rectangular. The bottom 12a faces the opening 12h. The first side walls 12b are flat. The first side walls 12b extend from the long sides of the bottom 12a. The second side walls 12c extend from the short sides of the bottom 12a. In a plan view, the area of ​​the first side walls 12b is larger than the area of ​​the second side walls 12c.

[0018] The sealing plate 14 is attached to the exterior body 12 so as to close the opening 12h of the exterior body 12. The sealing plate 14 faces the bottom 12a of the exterior body 12. The sealing plate 14 has a substantially rectangular shape in a plan view. The sealing plate 14 is provided with a thin-walled safety valve 17 that is configured to release the internal pressure of the box-shaped case 10 when the internal pressure of the box-shaped case 10 rises above a predetermined level, and an injection port (not shown) for injecting a non-aqueous electrolyte. The box-shaped case 10 is integrated by joining (preferably welding) the sealing plate 14 to the periphery of the opening 12h of the exterior body 12. The box-shaped case 10 is hermetically sealed (sealed). In this specification, the term "substantially rectangular" is intended to encompass not only a perfect rectangular shape (rectangular shape) but also, for example, a shape in which the corners connecting the long and short sides of the rectangle are rounded or a shape in which the corners have notches.

[0019] A positive electrode terminal 30 and a negative electrode terminal 40 are provided on the box-shaped case 10. Here, the positive electrode terminal 30 and the negative electrode terminal 40 are provided on the sealing plate 14. One end of the positive electrode terminal 30 is electrically connected by a conductive member such as a bus bar outside the box-shaped case 10. The other end of the positive electrode terminal 30 is electrically connected to the positive electrode of the electrode body inside the box-shaped case 10. One end of the negative electrode terminal 40 is electrically connected by a conductive member such as a bus bar outside the box-shaped case 10. The other end of the negative electrode terminal 40 is electrically connected to the negative electrode of the electrode body inside the box-shaped case 10.

[0020] Fig. 3 is a schematic exploded view of a housing 200 according to one embodiment. The housing 200 accommodates a plurality of power storage devices 100 therein. As shown in Fig. 3, the housing 200 includes a bottom cover 210, side frames 220, end frames 230, and a top cover 240. The above-described members constituting the housing 200 each form a framework that holds the power storage devices 100.

[0021] Here, the bottom cover 210 constitutes the bottom surface of the electricity storage pack 500. The bottom cover 210 is arranged so as to cover the plurality of electricity storage devices 100 and at least a portion of the side frame 220 (more specifically, the first flange portion 221). The plurality of electricity storage devices 100 are arranged on the bottom cover 210. More specifically, the bottom portion 12a of the electricity storage device 100 and the bottom cover 210 are arranged via a first adhesive 410. This allows the electricity storage device 100 to be fixed onto the bottom cover 210. Furthermore, when the electricity storage pack 500 is in use, heat generated in the electricity storage device 100 can be conducted to the bottom cover 210 via the bottom portion 12a. Note that the bottom cover 210 may be equipped with, for example, a cooling mechanism.

[0022] The side frames 220 are members disposed at the ends of the power storage device 100 in the arrangement direction (X-axis direction). As shown in FIG. 3, the side frame 220 includes a base portion 225 and a first flange 221, a second flange 222, a third flange 223, and a fourth flange 224 extending from each end of the base portion 225. The first flange 221 and the second flange 222 of the side frame 220 are disposed opposite each other. The third flange 223 and the fourth flange 224 of the side frame 220 are disposed opposite each other. As shown in FIG. 1, here, a pair of side frames 220 are disposed at the ends of the power storage device 100 in the arrangement direction (X-axis direction). This sandwiches the power storage device 100 in the arrangement direction.

[0023] The end frames 230 are members arranged in a direction (Y-axis direction) perpendicular to the arrangement direction of the power storage devices 100. As shown in FIG. 1, a pair of end frames 230 are arranged at the ends of the power storage devices 100 in the direction (Y-axis direction) perpendicular to the arrangement direction. This sandwiches the power storage devices 100 and the side frames 220 in the direction perpendicular to the arrangement direction. In this embodiment, one end frame 230 (the rear end frame in FIG. 3) is integrated with the bottom cover 210. However, without being limited to this, in some embodiments, the end frame 230 and the bottom cover 210 may each be independent members.

[0024] The top cover 240 constitutes the upper part of the housing 200. The top cover 240 is disposed so as to cover the side frames 220 and the end frames 230. The top cover 240 faces the bottom cover 210. Here, the top cover 240 has a substantially rectangular shape in a plan view.

[0025] The housing 200 is airtightly sealed (sealed) by joining together the bottom cover 210, the side frames 220, the end frames 230, and the top cover 240. In this embodiment, the joining is performed using a second adhesive 420, which will be described later. This makes it possible to prevent water and the like from entering the inside of the electricity storage pack 500 (housing 200) when the electricity storage pack 500 is in use.

[0026] Fig. 4 is a partially enlarged cross-sectional view schematically showing the inside of an electricity storage pack 500 according to one embodiment. More specifically, Fig. 4 schematically shows the vicinity of the left side (L side) side frame 220 within the inside of the electricity storage pack 500. For ease of explanation, the top cover 240 is not shown in Fig. 4.

[0027] As shown in FIG. 4, in an electricity storage pack 500 according to this embodiment, a spacer 310 is disposed between adjacent electricity storage devices 100. More specifically, the spacer 310 is disposed between adjacent separators 320 (or between the partition wall 350 and the separator 320). Here, the spacer 310 can contribute to equalizing the confining pressure on the opposing surfaces of adjacent electricity storage devices 100. The spacer 310 can be made of, for example, a resin material. Examples of resin materials include natural rubber, synthetic rubber, silicone resin, and urethane resin. The spacer 310 is not an essential component.

[0028] As shown in FIG. 4, in an electricity storage pack 500 according to this embodiment, a separator 320 is disposed between a spacer 310 and an electricity storage device 100. The separator 320 insulates adjacent electricity storage devices 100 from each other. The separator 320 may be made of, for example, a resin material. Examples of resin materials include polycarbonate. The separator 320 is not an essential component.

[0029] When the separator 320 is disposed in the electricity storage pack 500, from the viewpoint of facilitating the assembly of the bottom cover 210 and the side frame 220, it is preferable that the height of the separator 320 be the same as or smaller (lower) than the height of the side frame 220. In other words, it is preferable that the separator 320 is disposed so that the end portion thereof is located on the U side of the first flange portion 221 of the side frame 220.

[0030] The electricity storage pack 500 disclosed herein is characterized by including a partition wall 350. The partition wall 350 is a plate-shaped member that separates the first adhesive 410 and the second adhesive 420 and prevents them from mixing with each other. As shown in FIG. 4 , the partition wall 350 is disposed between the base surface 250 of the side frame 220 and the first side wall 12b of the electricity storage device 100. The partition wall 350 has a contact point 352 where the bottom cover 210 and the partition wall 350 come into contact with each other. This defines a second region 200b where the side frame 220, the bottom cover 210, and the partition wall 350 face each other.

[0031] A flexible resin material that can be deformed by an external force can be suitably used for the partition wall 350. For example, polycarbonate or the like can be suitably used as the resin material, but the present invention is not limited to this.

[0032] The thickness of the partition wall 350 is preferably at least 0.15 mm or more, and more preferably 0.2 mm or more. By providing the partition wall 350 with a sufficient thickness, it is possible to further prevent the first adhesive 410 and / or the second adhesive 420 from climbing over the partition wall 350. This makes it possible to suitably prevent the first adhesive 410 and the second adhesive 420 from mixing with each other. On the other hand, the upper limit of the thickness of the partition wall 350 is not particularly limited, but is, for example, 1.0 mm or less, and preferably 0.5 mm or less, in view of the size constraints required for the electricity storage pack 500.

[0033] The Young's modulus of the partition wall 350 is preferably 2400 MPa or more, and more preferably 3000 MPa or more. On the other hand, there is no particular upper limit to the Young's modulus of the partition wall 350, but from the viewpoint of optimizing the pressing load of the side frame 220 during manufacturing, it is, for example, 5000 MPa or less, and preferably 4000 MPa or less. Note that the "Young's modulus" in this specification can be measured using a conventionally known device according to the method specified in JIS K 7161-1:2014.

[0034] The width of the partition wall 350 corresponding to the width direction (Y-axis direction) of the side frame 220 is preferably wider than the width where the first adhesive 410 is provided, from the viewpoint of suppressing mixing of the first adhesive 410 and the second adhesive 420. In the width direction (Y-axis direction) of the side frame 220, if the width where the first adhesive 410 is provided is taken as 100%, the width of the partition wall 350 is preferably, for example, 103% or more and 130% or less.

[0035] The end 350a of the partition wall 350 may be disposed between the surface (more specifically, the bottom 12a) of the box-shaped case 10 of the power storage device 100 and the bottom cover 210, or may be disposed between the side frame 220 (first flange portion 221) and the bottom cover 210. As shown in FIG. 5 , the end 350a of the partition wall 350 is disposed between the surface (more specifically, the bottom 12a) of the box-shaped case 10 of the power storage device 100 and the bottom cover 210. This can further enhance the adhesiveness between the bottom cover 210 and the side frame 220 by the second adhesive 420. The end 350a of the partition wall 350 is an example of an "end closer to the end than the contact point of the partition wall" in this specification.

[0036] In this embodiment, the partition wall 350 has a curved portion 354 in addition to the contact point 352. As shown in FIG. 4, the curved portion 354 is disposed between the contact point 352 and a contact portion 350c, which is a portion where the partition wall 350 and the side frame 220 come into contact. Here, the curved portion 354 curves in the direction in which the first adhesive 410 is disposed (toward the right in FIG. 4; in other words, toward the first region 200a). At this time, the formation (curving) of the curved portion 354 generates a repulsive force in the direction opposite to the curvature of the partition wall 350 (toward the left in FIG. 4; in other words, toward the second region 200b). This repulsive force acts as a reaction force that resists the force that causes the first adhesive 410 to invade the second adhesive 420 (toward the second region 200b). Therefore, mixing of the first adhesive 410 and the second adhesive 420 can be more effectively suppressed. The curved portion 354 may be curved in the direction in which the second adhesive 420 is disposed (toward the second region 200b). This configuration can suitably prevent the second adhesive 420 from penetrating into the first adhesive 410. The curved portion 354 is not essential.

[0037] The other end of the partition wall 350 (the end located near the top cover 240) may be provided below the second flange portion 222 of the side frame 220. In other words, the partition wall 350 and the top cover 240 do not necessarily need to be in contact with each other (to have a contact point).

[0038] Although not particularly limited thereto, in this embodiment, the partition wall 350 is attached to the base portion 225 of the side frame 220. In some embodiments, it is preferable that the partition wall 350 is attached to the side frame 220. This configuration prevents the partition wall 350 from shifting position. This more effectively prevents the first adhesive 410 and the second adhesive 420 from mixing. There is no particular limitation on the method for attaching the side frame 220 and the partition wall 350, but it is preferable to apply the first adhesive 410 and the second adhesive 420 after the side frame 220 and the partition wall 350 are completely fixed (attached).

[0039] As shown in FIG. 4 , the electricity storage pack 500 disclosed herein includes a first adhesive 410 disposed on a surface where the electricity storage device 100 (bottom 12 a) and the bottom cover 210 face each other. In other words, the first adhesive 410 is disposed in a first region 200 a, which is a region where the electricity storage device 100 (bottom 12 a) and the bottom cover 210 face each other. Here, the first adhesive 410 is disposed along the width direction (Y-axis direction) of the electricity storage device 100. The first adhesive 410 fixes the electricity storage device 100 and the bottom cover 210 together. This makes it possible to prevent the electricity storage device 100 from moving inside the housing 200 due to vibration or impact when the electricity storage pack 500 is in use. Furthermore, fixing the electricity storage device 100 and the bottom cover 210 together makes it possible to suitably conduct heat from the electricity storage device 100 (here, the bottom 12 a) to the bottom cover 210. In this embodiment, the first adhesive 410 also serves as an insulating member that insulates the power storage device 100 from the bottom cover 210.

[0040] The first adhesive 410 can be an adhesive for structural applications, heat conduction applications, insulation applications, sealing applications, or an adhesive combining two or more of the above applications. In this specification, "structural adhesive" refers to a reliable adhesive that can withstand large loads for a long period of time (JIS K 6800). An example of an adhesive for structural applications is an epoxy resin adhesive, which is preferably used. The epoxy resin adhesive may be either a one-component type or a two-component type, but from the viewpoint of handling, a one-component type is preferable. Examples of one-component epoxy adhesives include bisphenol epoxy resins and hydrogenated bisphenol epoxy resins.

[0041] The amount of first adhesive 410 applied can be changed as appropriate depending on the type of adhesive used. From the viewpoint of ensuring sufficient adhesion between the bottom cover 210 and the electricity storage device 100, the amount of first adhesive 410 applied is, for example, 0.5 mm or more, preferably 1 mm or more, after manufacture (after the bottom cover 210 is attached) on the bottom 12a of the electricity storage device 100. On the other hand, the amount of first adhesive 410 applied is not particularly limited, but from the viewpoint of cost, etc., it is, for example, 5 mm or less, preferably 4 mm or less.

[0042] The viscosity of the first adhesive 410 is preferably 460 Pa·s or less, and more preferably 300 Pa·s or less. This allows the first adhesive 410 to deform favorably, facilitating adhesion between the bottom cover 210 and the electricity storage device 100. The lower limit of the viscosity of the first adhesive 410 is not particularly limited, but from the viewpoint of workability, it may be, for example, 50 Pa·s or more, and preferably 100 Pa·s or more. Note that the "viscosity" in this specification is measured using a commercially available rheometer at a measurement temperature of 25°C and a shear rate of 10 to 600 s -1 This refers to the viscosity (Pa·s) measured in

[0043] 4, the electricity storage pack 500 disclosed herein includes a second adhesive 420 arranged in a second region 200b, which is a region where the side frame 220, the bottom cover 210, and the partition wall 350 face each other. With this configuration, the side frame 220 and the bottom cover 210 are bonded together, and the gap between the side frame 220 and the bottom cover 210 is filled with the second adhesive 420. Here, the second adhesive 420 is arranged along the width direction (Y-axis direction) of the electricity storage device 100. Furthermore, the second adhesive 420 is arranged in a region separated from the first adhesive 410.

[0044] In this embodiment, the housing 200 is assembled by bonding the bottom cover 210, the side frames 220, the end frames 230, and the top cover 240 together with the second adhesive 420. This seals (hermetically seals) the inside of the housing 200.

[0045] The second adhesive 420 is different from the first adhesive 410. As the second adhesive 420, an adhesive for sealing, structural, thermal conduction, or insulation purposes, or an adhesive combining two or more of the above purposes can be used. Among them, an adhesive for sealing purposes can be preferably used from the viewpoint of suitably sealing (hermetically sealing) the inside of the housing 200. An example of an adhesive for sealing purposes is a modified silicone adhesive.

[0046] The viscosity of the second adhesive 420 is preferably 460 Pa·s or less, and more preferably 300 Pa·s or less, which allows the second adhesive 420 to deform favorably and facilitates bonding between the bottom cover 210 and the side frame 220. There is no particular lower limit to the viscosity of the first adhesive 410, but from the standpoint of workability, it may be, for example, 200 Pa·s or more, and preferably 250 Pa·s or more.

[0047] The amount of second adhesive 420 applied can be varied as appropriate depending on the type of adhesive used. From the viewpoint of ensuring sufficient adhesion between the bottom cover 210 and the side frame 220, the amount of second adhesive 420 applied is, for example, 1.5 mmφ or more in diameter, and preferably 2.0 mmφ or more in diameter. On the other hand, the amount of second adhesive 420 applied is not particularly limited, but from the viewpoint of cost, etc., it is, for example, 5 mmφ or less in diameter, and preferably 3 mmφ or less in diameter.

[0048] Fig. 5 is a view corresponding to Fig. 4, illustrating the assembly of the bottom cover 210 according to one embodiment. For ease of explanation, Fig. 5 is inverted vertically (Z-axis direction), and illustrates the direction of gravity G. Also, Fig. 5 does not illustrate the top cover 240.

[0049] As shown in FIG. 5, the power storage device 100 is placed so that the bottom 12a of the power storage device 100 and the first flange 221 of the side frame 220 face upward in the direction of gravity G. A first adhesive 410 is disposed on the bottom 12a of the multiple power storage devices 100. Meanwhile, a second adhesive 420 is disposed on the first flange 221 of the side frame 220. Although not shown, in this embodiment, the second adhesive 420 is disposed in an area of ​​the end frame 230 that faces the bottom cover 210. In this state, the bottom cover 210 is disposed so as to cover the multiple power storage devices 100, the first flange 221 of the side frame 220, and the end frame 230. Then, the bottom cover 210 is pressed from the outer surface of the bottom cover 210 in a vertical direction (the direction of the white arrow in FIG. 5) against the first flange 221 of the side frame 220. This pressing force changes the shape of the first adhesive 410 (in other words, it is crushed), and the bottom 12a of the electricity storage device 100 and the bottom cover 210 are bonded together. This fixes the electricity storage device 100 and the bottom cover 210 together. Similarly, the force pressing the bottom cover 210 (in the direction of the white arrow in FIG. 5 ) changes the shape of the second adhesive 420, bonding the side frame 220 (first flange portion 221) and the bottom cover 210 together, and the gap between the first flange portion 221 and the bottom cover 210 is filled with the second adhesive 420.

[0050] In the case of conventional energy storage packs without partition walls, when assembling the energy storage pack using different types of adhesives as described above, when the bottom cover is pressed, one adhesive may deform due to the pressing force and infiltrate into the area where the other adhesive is located, causing the different adhesives to mix together. This can change the performance of each adhesive (e.g., a decrease in adhesion, elongation, or volume resistivity), potentially impairing their functionality. For example, the adhesive strength between the energy storage device and the bottom cover may be insufficient, causing the energy storage device to move inside the energy storage pack due to vibrations during use. Furthermore, the sealing between the bottom cover and the side frame may be impaired, potentially allowing water or other substances to enter the energy storage pack.

[0051] In contrast, the electricity storage pack 500 disclosed herein includes a partition wall 350 disposed between the side frame 220 and the electricity storage device 100. With this configuration, when the bottom cover 210 is pressed, the bottom cover 210 and the partition wall 350 come into contact with each other, forming a contact point 352. This prevents the first adhesive 410 from passing over the partition wall 350 and entering the second region 200b. At the same time, the second adhesive 420 from passing over the partition wall 350 and entering the first region 200a. In other words, with the electricity storage pack 500 configured as described above, it is possible to prevent the first adhesive 410 and the second adhesive 420 from mixing with each other.

[0052] Furthermore, because the electricity storage pack 500 of the present disclosure is provided with the partition wall 350, there is no need to provide an additional groove or the like for guiding the adhesive. Therefore, it is thought that a secondary effect of the electricity storage pack 500 of the present disclosure is that the electricity storage pack can be made smaller.

[0053] As shown in FIG. 5 , the partition wall 350 in this embodiment has a bending point 356. More specifically, the partition wall 350 is bent toward the side frame 220 such that the end 350 a faces the power storage device 100. The bending point 356 is a portion corresponding to the contact point 352 after the bottom cover 210 is assembled ( FIG. 4 ). The end 350 a of the partition wall 350 is disposed closer to the bottom cover 210 than the bending point 356. In other words, as shown in FIG. 5 , the angle formed by the surface extending from the end 350 a of the partition wall 350 to the bending point 356 and the surface extending from the bending point 356 to the other end of the partition wall 350 is an obtuse angle. This configuration allows the positions of the contact point 352 and the end 350 a of the partition wall 350 to be suitably adjusted when the bottom cover 210 is assembled. Furthermore, when the partition wall 350 has the bending point 356, it is preferable that the bending point 356 be located closer to the first flange portion 221 of the side frame 220. This allows the curved portion 354 to be formed when the bottom cover 210 is assembled. However, the shape of the partition wall 350 before the bottom cover 210 is assembled is not limited to the above-mentioned form.

[0054] For example, in the partition wall 350 having the above-described shape, when the bottom cover 210 is pressed, first, the bottom cover 210 and the end portion 350a of the partition wall 350 come into contact. As a result, stress is transmitted to the partition wall 350, and the partition wall 350 begins to deform around the bending point 356. Then, the bending point 356 comes into contact with the bottom cover 210, forming a contact point 352. As a result, a pressing force in the pressing direction of the bottom cover 210 (indicated by the white arrow in FIG. 5 ) is transmitted to the partition wall 350 through the bending point 356. This pressing force generates a bending moment, forming a curved portion 354. In this way, the contact point 352 and the curved portion 354 are formed in the partition wall 350. However, this is merely an example.

[0055] The electricity storage pack 500 can be used for various purposes, but can be suitably used, for example, as a power source (driving power source) for a motor mounted on a vehicle such as a passenger car, a truck, etc. The type of vehicle is not particularly limited, but examples include a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), and a battery electric vehicle (BEV).

[0056] As described above, specific aspects of the technology disclosed herein include those described in the following sections.

[0057] Item 1: An electricity storage pack including a plurality of electricity storage devices each having a hexahedral box-shaped case arranged along a predetermined arrangement direction, side frames arranged at ends in the arrangement direction, and a cover arranged so as to cover the plurality of electricity storage devices and at least a portion of the side frames, the electricity storage pack having a plate-shaped partition wall arranged between the side frames and the electricity storage devices, the partition wall having contact points in contact with the cover, a first adhesive arranged on a surface where the electricity storage devices and the cover face each other, and a second adhesive arranged in a region where the side frames, the partition wall, and the cover face each other and which is isolated from the first adhesive. Item 2: The electricity storage pack according to item 1, wherein an end of the partition wall closer to the distal end than the contact point is disposed between the surface of the box-shaped case of the electricity storage device and the cover. Item 3: The electricity storage pack according to item 1 or 2, wherein the partition wall further has a curved portion between the contact point and a portion where the partition wall contacts the side frame. Item 4: The electricity storage pack according to any one of Items 1 to 3, wherein the partition wall has a thickness of at least 0.15 mm or more. Item 5: The electricity storage pack according to any one of Items 1 to 4, wherein the viscosity of the first adhesive is 460 Pa·s or less. Item 6: The electricity storage pack according to any one of Items 1 to 5, wherein the viscosity of the second adhesive is 460 Pa·s or less. Item 7: The electricity storage pack according to any one of items 1 to 6, wherein the width of the partition wall is wider than the width of the area where the first adhesive is provided. Item 8: The electricity storage pack according to any one of items 1 to 7, wherein the partition wall is attached to the side frame. [Explanation of symbols]

[0058] 10: Box-shaped case 12: Exterior body 12a: Bottom 12b: 1st side wall 12c: 2nd side wall 14: Sealing plate 100: Energy storage device 200: Cabinet 200a: 1st area 200b:Second area 210: Bottom cover 220: Side frame 221: First flange part 222: Second flange part 223: Third flange 224: 4th flange part 225: Base part 230: End frame 240: Top cover 310: Spacer 320: Separator 350: Partition wall 350a: End 352: Contact 354: Curved section 356: Bend point 410: First adhesive 420: Second adhesive 500: Energy storage pack

Claims

1. a plurality of electricity storage devices each having a hexahedral box-shaped case arranged along a predetermined arrangement direction; a side frame disposed at an end in the arrangement direction; a cover disposed so as to cover the plurality of power storage devices and at least a portion of the side frame; An electricity storage pack comprising: a plate-shaped partition wall disposed between the side frame and the power storage device, the partition wall having a contact point in contact with the cover; a first adhesive disposed on a surface where the power storage device and the cover face each other; a second adhesive disposed in an area where the side frame, the partition wall, and the cover face each other, the second adhesive being separated from the first adhesive; Power storage pack.

2. The electricity storage pack according to claim 1 , wherein an end of the partition wall closer to the terminal end than the contact point is disposed between a surface of the box-shaped case of the electricity storage device and the cover.

3. The electricity storage pack according to claim 1 or 2, wherein the partition wall further has a curved portion between the contact point and a portion where the partition wall contacts the side frame.

4. The electricity storage pack according to claim 1 or 2, wherein the partition wall has a thickness of at least 0.15 mm or more.

5. The electricity storage pack according to claim 1 or 2, wherein the first adhesive has a viscosity of 460 Pa·s or less.

6. The electricity storage pack according to claim 1 or 2, wherein the second adhesive has a viscosity of 460 Pa·s or less.

7. The electricity storage pack according to claim 1 or 2, wherein a width of the partition wall is wider than a width of an area where the first adhesive is provided.

8. The electricity storage pack according to claim 1 or 2, wherein the partition wall is attached to the side frame.

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