accumulator pack

Abstract

The present application provides a power storage package in which a bottom cover is less likely to bulge at an intersection of a ventilation flow path and a refrigerant flow path. The power storage package disclosed herein includes a plurality of power storage devices and a housing. The housing has a main body portion (610), a bottom cover (640), a ventilation flow path (EP), and a refrigerant flow path (FP) provided between a bottom surface (610a) of the main body portion (610) and the bottom cover (640). The bottom surface (610a) has a ventilation recess (611), a refrigerant recess (613), and a boss portion (619) protruding toward the bottom cover (640) at a position on the ventilation recess (611) side than a seal member (660) at an intersection (BP) of the ventilation recess (611) and the refrigerant recess (613), and the bottom cover (640) is threadedly fixed to the boss portion (619).

Description

Technical Field

[0001] This invention relates to energy storage packs. Background Technology

[0002] Conventionally, energy storage packs have been used as power sources for vehicle propulsion, comprising multiple energy storage devices and a housing for accommodating these devices. In this regard, for example, Japanese Patent Application Publication No. 2020-61291 (Patent Document 1) discloses an energy storage pack in which the housing comprises a main body having a bottom surface and a plate-shaped bottom cover covering the bottom surface from the outer surface side. The bottom cover is threaded to a fixing part provided on the bottom surface, and a refrigerant flow path is provided between the bottom surface and the bottom cover.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-61291 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Between the bottom surface of the main body and the bottom cover, in addition to the refrigerant flow path described above, a ventilation path (ventilation path) is sometimes provided for purposes such as venting gas discharged from the energy storage device. However, at the junction of the ventilation path and the refrigerant flow path, the wall thickness is relatively thin, making it difficult to install a fixing part. Therefore, the bottom cover can easily bulge significantly under the influence of refrigerant pressure. Consequently, it can be difficult to maintain the sealing of the refrigerant flow path.

[0008] The present invention was made in view of the above circumstances, and its main objective is to provide a battery pack in which the bottom cover is less likely to bulge at the junction of the air passage and the refrigerant passage.

[0009] Solution for solving the problem

[0010] According to the present invention, a battery pack comprising a plurality of energy storage devices and a housing for accommodating the plurality of energy storage devices is disclosed. The housing comprises: a main body having a bottom surface; a bottom cover covering the bottom surface from an outer surface side; an airflow passage disposed between the bottom surface and the bottom cover, communicating with the outside of the housing; a refrigerant flow passage disposed between the main body and the bottom cover for refrigerant flow; and a sealing member configured to surround the outer edge of the refrigerant flow passage, attached to the bottom surface and the bottom cover to seal the refrigerant flow passage. The bottom surface of the main body has the following features on the side facing the bottom cover: a venting recess that is recessed away from the bottom cover and divides the venting flow path; a refrigerant recess that is adjacent to the venting recess via the sealing member at least in a portion and is recessed away from the bottom cover and divides the refrigerant flow path; and a boss that protrudes toward the bottom cover at the junction of the venting recess and the refrigerant recess, at a position closer to the venting recess than the sealing member, and the bottom cover is threadedly fixed to the boss.

[0011] According to the present invention, by providing a boss at the junction, the overlap allowance of the screws can be ensured. Therefore, a fixing part can be provided at the junction of the bottom cover, improving the integrity of the main body and the bottom cover. Consequently, bulging of the bottom cover caused by refrigerant pressure can be suppressed. Furthermore, the sealing performance of the refrigerant flow path can be improved. Attached Figure Description

[0012] Figure 1 This is a perspective view schematically illustrating one embodiment of a battery pack.

[0013] Figure 2 It is a schematic representation Figure 1 A 3D view of the energy storage module.

[0014] Figure 3 It is a schematic 3D diagram representing a single energy storage device.

[0015] Figure 4 It is a schematic representation Figure 1 A top view of the bottom surface of the shell.

[0016] Figure 5 yes Figure 4 VV-line sectional view. Detailed Implementation

[0017] Hereinafter, preferred embodiments of the technology disclosed herein will be described with appropriate reference to the accompanying drawings. Matters necessary for implementing the technology disclosed herein, other than those specifically mentioned in this specification (e.g., the general structure and manufacturing process of energy storage devices that do not characterize the technology disclosed herein), can be grasped by those skilled in the art based on prior art in the field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the field.

[0018] Figure 1 This is a perspective view schematically illustrating an embodiment of a battery pack 800. Furthermore, in the following figures, reference numerals F, Rr, L, R, U, and D represent front, back, left, right, top, and bottom, respectively; reference numerals X, Y, and Z represent a first direction, a second direction orthogonal to the first direction, and a third direction orthogonal to both the first and second directions, respectively. The first direction X is the arrangement direction of the battery storage devices described later. The third direction Z is the vertical direction. However, these directions are merely for ease of explanation and do not limit the arrangement of the battery modules or battery pack. Additionally, in the following figures, components and parts that perform the same function are labeled with the same reference numerals, and sometimes repeated descriptions are omitted or simplified.

[0019] like Figure 1 As shown, the energy storage pack 800 of this embodiment includes multiple energy storage modules 500 and a housing 600. The housing 600 is a frame that houses the multiple energy storage modules 500. The material of the housing 600 can be the same as conventionally used materials, and there are no particular limitations. The housing 600 is preferably made of metal, and more preferably of aluminum, aluminum alloy, iron, iron alloy, stainless steel, etc. The housing 600 of this embodiment has a main body 610, an upper surface cover 620, and a bottom surface cover 640.

[0020] Here, the main body 610 has a bottom surface 610a (see reference). Figure 4 The main body 610 is a bottomed, cylindrical (box-shaped) part with an opening facing the bottom surface 610a. Here, the main body 610 is a casting formed by casting. The upper surface cover 620 is a component that seals the opening of the main body 610. The upper surface cover 620 constitutes the first surface of the housing 600 in the third direction Z (…). Figure 1 The main body 610 and the upper surface cover 620 are fastened together at multiple fastening parts 630 provided on the outer edge of the housing 600 to form an integral unit. The main body 610 and the upper surface cover 620 divide the housing 600 into a storage space 600A (first space). Multiple energy storage modules 500 are stored in the storage space 600A.

[0021] The bottom cover 640 covers the bottom surface 610a of the main body 610 from the outer surface side (see reference). Figure 4The bottom cover 640 is arranged facing the bottom surface 610a. Here, the bottom cover 640 is a plate-shaped member. The bottom cover 640 constitutes the second surface of the housing 600 in the third direction Z. Figure 1 The main body 610 and the bottom cover 640 are fastened together at multiple fastening parts 650 provided on the outer edge of the housing 600, etc., and are thus integrated. An exhaust flow path EP (second space, see below) communicating with the outside of the housing 600 is provided between the bottom surface 610a of the main body 610 and the bottom cover 640. Figure 4 ) and the refrigerant flow path FP (third space, reference) for refrigerant circulation. Figure 4 Details will be discussed later.

[0022] like Figure 1 As shown, the housing 600 is provided with an opening EO, an inlet FI, and an outlet FO. The opening EO is for the exhaust flow path EP (refer to...) Figure 4 The portion that communicates with the outside of the housing 600 (external air). Here, there are multiple openings EO (specifically two). Here, the multiple openings EO are located in the first direction X ( Figure 1 They are spaced apart on the front and back sides.

[0023] The inflow section FI is related to the refrigerant flow path FP (refer to...). Figure 4 This is the portion of the housing 600 from the outside into the refrigerant flow path FP, where the refrigerant flows in from the outside of the housing 600. Here, the inflow portion FI is located on the side of the housing 600 (specifically, the main body 610). Figure 1 (YZ side). The inlet FI is located on the side intersecting with the upper surface cover 620 and / or the bottom surface cover 640. Furthermore, as the refrigerant, refrigerants known conventionally suitable for this application can be used without particular limitation. For example, liquids such as cooling water can be listed.

[0024] The outflow section FO is connected to the refrigerant flow path FP (refer to...). Figure 4 This is a portion that allows the refrigerant flowing in the refrigerant flow path FP to flow out of the housing 600. Here, the outflow portion FO is provided on the side of the housing 600 (specifically, the main body 610). Figure 1 (YZ surface). Here, the outlet FO is provided on the same surface of the housing 600 as the inlet FI. The outlet FO is provided on the surface that intersects with the upper surface cover 620 and / or the bottom surface cover 640.

[0025] like Figure 1As shown, here, there are multiple (specifically three) energy storage modules 500, arranged in the second direction Y within the storage space 600A of the housing 600. Furthermore, the number and arrangement of the energy storage modules 500 are not particularly limited. For example, there may be three or fewer energy storage modules, or even just one. Additionally, the energy storage modules 500 may also be arranged in the first direction X. Furthermore, the structure of the energy storage modules 500 is not particularly limited and can be the same as conventional ones.

[0026] Figure 2 This is a schematic perspective view of the energy storage module 500. The energy storage module 500 of this embodiment includes a plurality of energy storage devices 100 arranged along an arrangement direction X and spacers 200 arranged between adjacent energy storage devices 100 in the arrangement direction X. Here, the energy storage module 500 also includes a constraint mechanism 300 configured to apply a predetermined constraint load to the plurality of energy storage devices 100 from the arrangement direction X. Thus, the plurality of energy storage devices 100 are held together as a single unit.

[0027] Furthermore, in this embodiment, multiple energy storage devices 100 are configured within the housing 600 in a so-called Cell-Module-Pack structure housed within the restraint mechanism 300. However, in other embodiments, multiple energy storage devices 100 may also be configured within the housing 600 in a so-called Cell-to-Pack structure directly supported on the wall of the housing 600.

[0028] The spacer 200 is a component used to separate the multiple energy storage devices 100. The spacer 200 is preferably an insulating component. Here, the spacers 200 are respectively disposed between the multiple energy storage devices 100 in the arrangement direction X. That is, in the energy storage module 500, the energy storage devices 100 and the spacers 200 are arranged alternately in the arrangement direction X. However, the spacers 200 are not essential and can be omitted in other embodiments.

[0029] The energy storage device 100 is a device capable of repeated charging and discharging. Furthermore, in this specification, "energy storage device" includes the concept of secondary batteries such as lithium-ion batteries and nickel-metal hydride batteries, and capacitors such as lithium-ion capacitors, pseudocapacitive capacitors, and double-layer capacitors.

[0030] Multiple energy storage devices 100 are arranged along the arrangement direction X (the thickness direction of the energy storage device 100). In this embodiment, the even-numbered energy storage device 100 in the arrangement direction X is configured in a state of rotation (flipped state) relative to the odd-numbered energy storage device 100 in the arrangement direction X. Here, the multiple energy storage devices 100 have the same shape and size. However, the shape, size, number, etc. of the multiple energy storage devices 100 constituting the energy storage module 500 are not limited to... Figure 2The method can be changed appropriately.

[0031] Figure 3 This is a 3D view of the energy storage device 100. (For example...) Figure 3 As shown, the energy storage device 100 is a flat, square shape. The energy storage device 100 is a square secondary battery. The energy storage device 100 of this embodiment includes a battery casing 10, electrode bodies (not shown), and an electrolyte. Here, the energy storage device 100 is a non-aqueous electrolyte secondary battery, specifically a lithium-ion secondary battery.

[0032] The battery casing 10 is a container for housing the electrodes and electrolyte. For example... Figure 3 As shown, the battery casing 10 has a flat, rectangular (square) shape. The material of the battery casing 10 can be the same as conventionally used materials, without particular limitation. The battery casing 10 is preferably made of metal, and more preferably of aluminum, aluminum alloy, iron, iron alloy, stainless steel, etc. Here, the battery casing 10 includes a casing body 12 with an opening and a sealing plate 14 (cover) for sealing the opening.

[0033] Here, the main body 12 of the housing is a bottomed rectangular tube. The main body 12 of the housing includes: a lower surface 12a that is generally rectangular with long sides and short sides; a pair of long side surfaces 12b that extend from the pair of long sides of the lower surface 12a and face each other; and a pair of short side surfaces 12c that extend from the pair of short sides of the lower surface 12a and face each other. The lower surface 12a is the surface facing the bottom surface 610a of the housing 600. The long side surfaces 12b are the surfaces orthogonal to the arrangement direction X. Here, the long side surfaces 12b are the surfaces facing (more specifically, abutting) the spacer 200. In addition, in this specification, "generally rectangular" is a term that includes not only a complete rectangle (rectangle) but also shapes such as those in which the corners connecting the long and short sides of a rectangle are rounded (rounded corners), or shapes with cutouts at the corners.

[0034] The electrode body and electrolyte are housed inside the main body 12. The electrode body has a positive electrode and a negative electrode. The electrolyte is typically a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt (electrolyte salt). The electrode body and electrolyte can be the same as before, therefore, detailed description is omitted here.

[0035] like Figure 3 As shown, the sealing plate 14 is generally rectangular when viewed from above. The sealing plate 14 is a plate-like member extending along the XY plane. The sealing plate 14 is mounted on the opening of the housing body 12. The sealing plate 14 is the surface facing the upper surface cover 620 of the housing 600. The battery housing 10 is integrated by joining (preferably welding) the sealing plate 14 to the periphery of the opening of the housing body 12. The battery housing 10 is hermetically sealed (airtightly sealed).

[0036] The sealing plate 14 is provided with an injection hole 15, a gas vent valve 17, a positive terminal 30, and a negative terminal 40. The injection hole 15 is used to inject electrolyte into the battery housing 10 after the sealing plate 14 is assembled to the housing body 12. The injection hole 15 is sealed by the sealing member 16 after the electrolyte is injected. The gas vent valve 17 is configured to break when gas is generated inside the battery housing 10 and the internal pressure of the battery housing 10 reaches a specified value due to the generated gas. As a result, the gas generated inside the battery housing 10 is discharged to the outside of the battery housing 10 via the gas vent valve 17, specifically to the storage space 600A of the housing 600.

[0037] The positive terminal 30 and the negative terminal 40 are respectively disposed at the two ends of the sealing plate 14 in the second direction Y. The positive terminal 30 is electrically connected to the positive electrode of the electrode body inside the housing body 12. The negative terminal 40 is electrically connected to the negative electrode of the electrode body inside the housing body 12.

[0038] Busbars are provided on the positive terminal 30 and the negative terminal 40 to electrically connect the multiple energy storage devices 100 to each other. In this embodiment, the positive terminal 30 of one of two adjacent energy storage devices 100 in the arrangement direction X and the negative terminal 40 of the other energy storage device 100 are electrically connected via the busbars. Thus, the multiple energy storage devices 100 are electrically connected in series. However, the connection method of the multiple energy storage devices 100 is not limited to series connection; for example, it can also be parallel connection, multiple series connection, multiple parallel connection, etc.

[0039] Figure 4 It is a top view schematically showing the bottom surface 610a of the main body 610 of the housing 600. Figure 5 yes Figure 4 A VV-line sectional view. Furthermore... Figure 4 This refers to the outer surface side of the bottom surface 610a (the side opposite to the storage space 600A), that is, the side facing the bottom cover 640. Figure 4 Flip the casing 600 over, so that the front and back directions are the same as... Figure 1 On the contrary. Additionally, in Figure 5 The bottom cover 640 is also shown in the middle.

[0040] like Figure 4 As shown, the bottom surface 610a of the main body 610 is divided into one side located in the second direction Y when viewed from above. Figure 4 The exhaust area AE on the right side and the other side located in the second direction Y ( Figure 4 The refrigerant region AF is located on the left side of the exhaust region AE. Here, the exhaust region AE and the refrigerant region AF are positioned adjacent to each other in the second direction Y. In the second direction Y, the exhaust region AE and the refrigerant region AF are separated at the boundary portion BP.

[0041] In the exhaust region AE located on the right side of the second direction Y, such as Figure 4 , Figure 5 As shown, an exhaust flow path EP is provided between the bottom surface 610a of the main body 610 of the housing 600 and the bottom cover 640. Figure 4 As shown, the exhaust flow path EP communicates with the outside of the housing 600 via multiple openings EO. Furthermore, the exhaust flow path EP communicates with the receiving space 600A (first space) of the housing 600 via the atmospheric connection 612. The exhaust flow path EP is a hollow portion, forming a flow path for exhaust from the atmospheric connection 612 to the openings EO. The exhaust flow path EP is an example of the "ventilation path" disclosed herein.

[0042] In the exhaust region AE, the bottom surface 610a of the main body 610 has an exhaust recess 611 and an atmospheric communication portion 612 on the side facing the bottom cover 640. For example... Figure 4 As shown, the exhaust recess 611 extends linearly along the first direction X. Figure 5 As shown, the venting recess 611 is recessed towards the side away from the bottom cover 640 (the side of the storage space 600A of the housing 600). The venting recess 611 is an example of the "venting recess" disclosed herein. Here, the venting recess 611 is approximately "U"-shaped when viewed in cross-section. The venting recess 611, together with the bottom cover 640, divides the venting flow path EP. The venting recess 611 (or the venting flow path EP) is preferably provided at a position where at least a portion overlaps with multiple energy storage devices 100 when viewed from above. This allows the energy storage pack 800 to save space. Furthermore, it allows for an increase in the energy density of the energy storage pack 800.

[0043] The atmospheric communication portion 612 is configured to maintain a predetermined pressure (typically atmospheric pressure) within the housing space 600A (first space) of the casing 600. For example... Figure 4 , Figure 5 As shown, the atmospheric communication part 612 has a communication hole 612H, a membrane 612M (ventilation membrane) that blocks the communication hole 612H, and a protective cover 612C that protects the membrane 612M. Figure 5 As shown, the connecting hole 612H is configured to penetrate the bottom surface 610a of the housing 600 in the third direction Z, thereby connecting the housing space 600A of the housing 600 with the exhaust flow path EP. Thus, in this embodiment, the exhaust flow path EP, which discharges gas generated from the multiple energy storage devices 100, constitutes a ventilation flow path.

[0044] The membrane 612M is a breathable membrane component. Typically, the membrane 612M is a porous membrane with minute pores. The membrane 612M is preferably a resin-based film; examples include films made of fluoropolymers such as polytetrafluoroethylene, polyolefin resins such as polyethylene or polypropylene, and polyester resins. More specifically, porous membranes made of the aforementioned resins, polyester nonwoven fabrics, etc., can be used. Here, the membrane 612M is configured to allow the passage of gases such as air while blocking the passage of liquids such as moisture. This suppresses the entry of moisture into the storage space 600A of the housing 600.

[0045] Here, the diaphragm 612M is configured to rupture when the gas discharge valve 17 of the energy storage device 100 breaks, discharging gas into the storage space 600A, and the internal pressure of the storage space 600A reaches or exceeds a predetermined value due to the discharged gas. When the diaphragm 612M ruptures, opening the connecting hole 612H, the gas discharged from the energy storage device 100 flows into the exhaust flow path EP through the connecting hole 612H. The gas flowing into the exhaust flow path EP is discharged from the opening EO to the outside of the housing 600. Thus, the gas is discharged from the storage space 600A of the housing 600 to the outside of the energy storage pack 800.

[0046] The protective cover 612C is, for example, a plate-shaped metal component, and is installed on the periphery of the connecting hole 612H in such a way that it covers the membrane 612M from the outer surface side. Here, the protective cover 612C and the bottom cover 640 are threadedly fixed to the boss portion 619 described later.

[0047] On the other hand, in the refrigerant region AF located on the other side (left side) of the second direction Y, such as Figure 4 , Figure 5 As shown, a refrigerant flow path FP for refrigerant flow is provided between the bottom surface 610a of the main body 610 of the housing 600 and the bottom cover 640, and a sealing member 660 is attached to the bottom surface 610a of the main body 610 and the bottom cover 640 to seal the refrigerant flow path FP. Figure 4 As shown, the refrigerant flow path FP is a hollow section that forms the flow path for refrigerant from the inlet section FI to the outlet section FO. The refrigerant flow path FP is adjacent to the exhaust flow path EP via a seal 660 at least a portion of its length.

[0048] like Figure 4 As indicated by the light gray markings, the seal 660 (also called a sealant) is configured to surround the outer edge of the refrigerant flow path FP. Here, the seal 660 is configured as a continuous line. The seal 660 is positioned between the outer edge of the refrigerant flow path FP and a plurality of fasteners 650. Thus, the refrigerant flow path FP is hermetically sealed (sealed), preventing refrigerant leakage. Figure 5 As shown, the seal 660 is formed by filling the sealing groove 615 (described later) with sealing material and then curing it.

[0049] As a sealing material, any sealing material known to be suitable for this purpose can be used without particular limitation. Examples include various resin-based sealing materials such as silicone (including modified silicone), acrylic, and polyurethane, as well as rubber-based sealing materials such as silicone rubber and butyl rubber. Silicone-based sealing materials containing silicone are preferred due to their good adhesion to many substrates. Furthermore, silicone-based sealing materials are relatively soft and easily deformed. Therefore, the technology disclosed herein is particularly effective.

[0050] Furthermore, from the viewpoint of workability, room-temperature curing sealants are preferred. Room-temperature curing sealants are broadly classified into single-component and two-component types. Single-component sealants typically cure by reacting with moisture in the air, thus eliminating the need for the cumbersome mixing of the two components required for two-component sealants, making them simpler. In some embodiments, the seal 660 is preferably made of a single-component silicone-based sealant. Commercially available single-component silicone-based sealants include, for example, "Sikasil (registered trademark) SI" manufactured by Sika Japan Co., Ltd.

[0051] like Figure 4 , Figure 5 As shown, in the refrigerant region AF, the bottom surface 610a of the main body 610 has a refrigerant recess 613, an abutment surface 614, and a sealing groove 615 on the side facing the bottom cover 640. Furthermore, as described above, the main body 610 is a casting formed by casting. Therefore, the various parts provided on the bottom surface 610a (refrigerant recess 613, abutment surface 614, and sealing groove 615) are integrally formed. Additionally, the abutment surface 614 and sealing groove 615 are not essential and can be omitted in other embodiments.

[0052] like Figure 5 As shown, the refrigerant recess 613 is recessed towards the side away from the bottom cover 640 (the side of the housing space 600A of the housing 600). Here, the refrigerant recess 613 is approximately "U"-shaped in cross-section. Here, the depth of the refrigerant recess 613 (the maximum length of the recess from the outer side of the bottom surface 610a towards the third direction Z; the same applies below) is deeper than the exhaust recess 611. The refrigerant recess 613, together with the bottom cover 640, divides the refrigerant flow path FP. The refrigerant recess 613 is adjacent to the exhaust recess 611 at least a portion via a seal 660.

[0053] The refrigerant recess 613 (or refrigerant flow path FP) is preferably located at least partially facing the storage space 600A that houses the multiple energy storage devices 100. The refrigerant recess 613 (refrigerant flow path FP) is preferably positioned so that, when viewed from above, at least a portion overlaps with each of the multiple energy storage modules 500 (or multiple energy storage devices 100). This allows the refrigerant to flow directly below the multiple energy storage devices 100, efficiently cooling the energy storage devices 100.

[0054] like Figure 4 As shown, the refrigerant recesses 613 are respectively arranged in a roughly U-shape directly below each of the multiple energy storage modules 500. Figure 4 In the example, a roughly U-shaped first portion P1 is provided directly below the first energy storage module 500, a roughly U-shaped second portion P2 is provided directly below the second energy storage module 500, and a roughly U-shaped third portion P3 is provided directly below the third energy storage module 500. The first to third portions P1 to P3 each have a pair of straight portions Ps extending along a first direction X and a curved portion Pf connecting the pair of straight portions Ps. The first portions P1 to the third portions P3 are interconnected via a connecting portion Pc that is roughly U-shaped. Figure 4 As shown by the middle arrow, the refrigerant flowing from the inlet section FI into the refrigerant flow path FP flows through the first part P1, the second part P2 and the third part P3 in sequence, and then flows out from the outlet section FO to the outside of the housing 600.

[0055] like Figure 5 As shown, the abutment surface 614 is a surface provided between the refrigerant recess 613 (refrigerant flow path FP) and the seal 660 (sealing groove 615), protruding towards the bottom cover 640 and abutting against the bottom cover 640. The abutment surface 614 is continuously provided from the refrigerant recess 613. The abutment surface 614 is formed flat (allowing for machining errors, etc.). Here, the abutment surface 614 is formed by surface finishing of the side of the bottom surface 610a facing the bottom cover 640 (the outer side).

[0056] like Figure 4 As indicated by the dark gray markings, in the bottom surface 610a, the abutment surface 614 is disposed along the refrigerant flow path FP. The abutment surface 614 is provided at the periphery of at least a portion of the refrigerant flow path FP, at the periphery of the refrigerant recess 613 (or the refrigerant flow path FP). In this embodiment, for example, in… Figure 5 At the portion representing the cross-section, specifically at the junction BP of the exhaust region AE and the refrigerant region AF, an abutment surface 614 is disposed between the refrigerant flow path FP and the seal 660. At the junction BP, the refrigerant flow path FP, the seal 660, and the abutment surface 614 extend in a strip shape along the first direction X.

[0057] In this embodiment, such as Figure 4 As shown, abutment surfaces 614a are also provided between the first portion P1 and the second portion P2, and between the second portion P2 and the third portion P3, of the refrigerant recess 613. The abutment surfaces 614a extend linearly along the first direction X between the first portion P1 and the second portion P2, and between the second portion P2 and the third portion P3. Multiple fastening portions 650 are provided on the abutment surfaces 614a. Fastening portions 650 are provided in the gaps between the multiple energy storage modules 500 on the abutment surfaces 614a. This improves the integration of the main body 610 and the bottom cover 640, and improves the airtightness of the refrigerant flow path FP.

[0058] like Figure 5 As shown, the sealing groove 615 is the portion where the seal 660 is disposed. The sealing groove 615 is formed at a distance from the bottom cover 640, and is lower than the contact surface 614. The sealing groove 615 is continuously provided from the contact surface 614. Here, the sealing groove 615 is approximately "U"-shaped when viewed in cross-section. Here, the depth of the sealing groove 615 is shallower than the depth of the exhaust recess 611 and the refrigerant recess 613. By providing the sealing groove 615, the seal 660 can be stably disposed at the desired position.

[0059] In addition, Figure 4 In this context, the sealing groove 615 is positioned at the same location as the seal 660 described above (shown in light gray). The sealing groove 615 is configured to surround the outer edge of the refrigerant flow path FP. The sealing groove 615 is disposed between the outer edge of the refrigerant flow path FP and a plurality of fastening portions 650. At at least a portion of the periphery of the refrigerant flow path FP, the sealing groove 615 is provided between the abutment surface 614 and the boss portion 619 described later (see reference). Figure 5 In this embodiment, a sealing groove 615 (seal 660) is provided between the abutment surface 614 and the boss 619 (or screw 670) in the junction of the exhaust region AE and the refrigerant region AF, the portion of the refrigerant recess 613 facing the connecting portion Pc, etc.

[0060] In this embodiment, such as Figure 5As shown, on the side of the bottom surface 610a facing the bottom cover 640, at the junction BP of the exhaust recess 611 (exhaust flow path EP) and the refrigerant recess 613 (refrigerant flow path FP), a boss 619 protruding towards the bottom cover 640 is provided. By providing the boss 619 at the junction BP, the overlap allowance of the screw 670 can be ensured. Thus, the bottom cover 640 can be threadedly fixed to the junction BP, thereby providing a fixing part. Therefore, the integrity of the main body 610 and the bottom cover 640 can be improved. As a result, bulging of the bottom cover 640 caused by refrigerant pressure can be suppressed.

[0061] Furthermore, by providing a fixing part at the junction BP, the seal 660 is less likely to be pulled up and down, thus suppressing damage to the seal 660. This improves the sealing performance of the refrigerant flow path FP. Consequently, it enhances the durability of the seal 660, preventing refrigerant leakage from the refrigerant flow path FP over a long period. Additionally, by employing the structure with the boss 619, the height of the energy storage pack 800 is less likely to increase, thus suppressing a decrease in volumetric energy density.

[0062] like Figure 5 As shown, the boss portion 619 is positioned closer to the exhaust recess 611 (outer edge side) than the seal 660 (or sealing groove 615). Here, the boss portion 619 is continuously provided from the sealing groove 615. It is positioned in the direction intersecting the straight portion Ps (refrigerant flow direction) of the refrigerant flow path FP. Figure 5 On the left and right sides, the boss 619 is disposed between the sealing groove 615 and the refrigerant recess 613.

[0063] Here, the boss portion 619 protrudes towards the bottom cover 640 from the sealing member 660 and the abutment surface 614. The protruding length (the length in the third direction Z) of the boss portion 619 protruding from the abutment surface 614 is preferably smaller than the thickness (plate thickness) of the plate-shaped bottom cover 640. The protruding length of the boss portion 619 is preferably 40-80% of the thickness of the bottom cover 640, more preferably 50-70%. In one example, the thickness of the bottom cover 640 is 4 mm, and the protruding length of the boss portion 619 is 2.5 mm.

[0064] The bottom cover 640 is threadedly fixed to the boss portion 619. Specifically, the bottom cover 640 has a through hole 640H facing the boss portion 619. In the bottom cover 640, a screw 670 (bolt, etc.) passes through the through hole 640H and is fixed by a fastener (nut, etc., not shown). In this embodiment, the protective cover 612C is threadedly fixed to the boss portion 619 together with the bottom cover 640. Specifically, the bottom cover 640 and the protective cover 612C overlap sequentially and are fastened to the outer surface of the boss portion 619 by screws 670. This improves the integrity of the protective cover 612C and the bottom cover 640. As a result, even if vibration, impact, or other forces are applied to the battery pack 800, the protective cover 612C is less likely to fall off.

[0065] In some embodiments, the bottom cover 640 preferably has a stepped portion 640S at a position facing the boss portion 619. Here, the stepped portion 640S is provided on the inner side of the bottom surface 610a of the main body portion 610 (the side facing the storage space 600A). The boss portion 619 and the stepped portion 640S fit together. This improves the integration of the main body portion 610 and the bottom cover 640. Compared with other parts (e.g., the part facing the exhaust flow path EP), the bottom cover 640 is formed thinner. The thickness of the thin-walled portion is preferably 20% to 60% of the thickness (plate thickness) of the bottom cover 640, more preferably 30% to 50%. In one example, it is 1.5 mm.

[0066] In some embodiments, the height of the step portion 640S is preferably the same as the protruding length of the boss portion 619 (to allow for machining errors, etc.). The boss portion 619 preferably abuts against the step portion 640S of the bottom cover 640. This allows for the suppression of the height of the battery pack 800 while ensuring a greater overlap allowance for the screws 670.

[0067] In some embodiments, the boundary portion BP is positioned opposite to the storage space 600A that houses the multiple energy storage devices 100. In other words, the boundary portion BP is positioned to overlap with the energy storage devices 100 (energy storage module 500) when viewed from above. The boss portion 619 is positioned opposite to the storage space 600A that houses the multiple energy storage devices 100. The boss portion 619 is positioned to overlap with the energy storage module 500 (energy storage device 100) when viewed from above. In this case, the wall thickness at the boundary portion BP is particularly thin, making it difficult to ensure the overlap allowance of the screws 670. Therefore, the technique disclosed herein is particularly effective.

[0068] In some embodiments, the bottom surface 610a of the main body 610 has a mounting surface 610F for mounting a plurality of energy storage devices 100 (energy storage modules 500) on the side facing the storage space 600A (the inner side) and a recessed portion 610D that is recessed from the mounting surface 610F toward the bottom cover 640. The mounting surface 610F is formed flat (allowing for machining errors, etc.). The recessed portion 610D is continuously provided from the mounting surface 610F. A connecting hole 612H is provided in the recessed portion 610D. By providing the connecting hole 612H in the recessed portion 610D, a stable gas flow path can be ensured within the storage space 600A, and the gas discharged from the energy storage device 100 can easily move smoothly to the exhaust flow path EP through the connecting hole 612H.

[0069] In this embodiment, the junction portion BP is positioned opposite to the recess 610D. In other words, the junction portion BP is positioned to overlap with the recess 610D when viewed from above. The boss portion 619 is positioned opposite to the recess 610D. The boss portion 619 is positioned to overlap with the recess 610D when viewed from above. In this case, the wall thickness at the junction portion BP is particularly thin, making it difficult to ensure the overlap allowance of the screw 670. Therefore, the technique disclosed herein is particularly effective.

[0070] like Figure 4 As shown, at the junction portion BP, a plurality of screws 670 (fixing parts) are preferably provided. In this embodiment, a plurality of screws 670 are provided at equal intervals along the first direction X (or the refrigerant flow direction in the refrigerant flow path FP). Furthermore, although in Figure 4 The diagram is omitted, but the boss 619 is also located in the same position as the screw 670. This allows the effects of the technology disclosed herein to be achieved at a higher level.

[0071] The battery pack 800 disclosed herein can be used for various purposes, such as preferably as a power source (drive power supply) for motors in passenger cars, trucks, and other vehicles. There are no particular limitations on the type of vehicle; examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0072] The preferred embodiments of the present invention have been described above, but these embodiments are merely examples. The present invention can be implemented in various other ways. The present invention can be implemented based on the disclosure in this specification and common technical knowledge in the field. The technology described in the claims includes technologies obtained by various modifications and alterations to the embodiments illustrated above.

[0073] As described above, the following are examples of specific methods that can be used as specific embodiments of the technology disclosed herein.

[0074] Item 1: A battery pack comprising a plurality of energy storage devices and a housing for housing the plurality of energy storage devices, the housing comprising: a main body having a bottom surface; a bottom cover covering the bottom surface from an outer surface side; an airflow passage disposed between the bottom surface and the bottom cover, communicating with the outside of the housing; a refrigerant flow passage disposed between the main body and the bottom cover for refrigerant flow; and a sealing member configured to surround the outer edge of the refrigerant flow passage, attached to the main body and the bottom cover to seal the refrigerant flow passage, wherein the main body... The bottom surface of the body has the following features on the side facing the bottom cover: a venting recess that is recessed away from the bottom cover to divide the venting flow path; a refrigerant recess that is adjacent to the venting recess via the sealing member at least in a portion and is recessed away from the bottom cover to divide the refrigerant flow path; and a boss that protrudes toward the bottom cover at the junction of the venting recess and the refrigerant recess, at a position closer to the venting recess than the sealing member, and the bottom cover is threadedly fixed to the boss.

[0075] Item 2: In the energy storage pack described in Item 1, the bottom surface of the main body also has a connecting hole on the side facing the bottom cover. The connecting hole is covered by a breathable membrane, which connects the storage space for accommodating multiple energy storage devices with the airflow path. The airflow path constitutes an exhaust path for discharging gas generated from the multiple energy storage devices.

[0076] Item 3: In the battery pack described in Item 2, the membrane is covered from the outer surface by a protective cover, and the protective cover and the bottom cover are threadedly fixed to the boss portion of the main body.

[0077] Item 4: In any one of items 1 to 3, the bottom cover has a stepped portion at a position facing the boss portion of the main body.

[0078] Item 5: In the battery pack described in Item 4, the aforementioned boss portion abuts against the aforementioned stepped portion of the aforementioned bottom cover.

[0079] Item 6: In any one of items 1 to 5, the bottom surface of the main body portion further has an abutment surface on the side facing the bottom cover. The abutment surface is disposed between the refrigerant recess and the sealing member, protrudes toward the bottom cover and abuts against the bottom cover, and the boss portion protrudes more than the abutment surface toward the bottom cover side.

[0080] Item 7: In any one of items 1 to 6, the aforementioned boundary portion is located opposite to the storage space that houses the plurality of the aforementioned energy storage devices.

[0081] Item 8: In the energy storage pack described in Item 7, the bottom surface of the main body has the following on the side facing the storage space: a mounting surface on which a plurality of the energy storage devices are mounted; and a recessed portion that is recessed from the mounting surface on the bottom cover side, and the boundary portion is provided at a position facing the recessed portion.

[0082] Explanation of reference numerals in the attached figures

[0083] 100 Storage devices

[0084] 500 energy storage module

[0085] 600 housing

[0086] 610 Main Body

[0087] 610a Bottom

[0088] 611 Vent recess (ventilation recess)

[0089] 612C Protective Cover

[0090] 612H Connecting Hole

[0091] 613 Refrigerant recess

[0092] 614 Contact Surface

[0093] 619 convex section

[0094] 640 bottom cover

[0095] 640S Step Section

[0096] 660 seal

[0097] EP exhaust flow path

[0098] FP refrigerant flow path

[0099] 800 battery pack.

Claims

1. A battery storage pack, wherein, The energy storage pack includes multiple energy storage devices and a housing for storing the multiple energy storage devices. The housing has: The main body has a bottom surface; A bottom cover that covers the bottom surface from the outer surface side; An airflow path is provided between the bottom surface and the bottom cover, and communicates with the outside of the housing; A refrigerant flow path is provided between the bottom surface and the bottom cover for refrigerant to flow through; as well as A sealing element, configured to surround the outer edge of the refrigerant flow path, is attached to the bottom surface and the bottom cover to seal the refrigerant flow path. The bottom surface of the main body has the following characteristics on the side facing the bottom cover: A ventilation recess is recessed to the side away from the bottom cover to divide the ventilation airflow path; A refrigerant recess, which is adjacent to the venting recess via the seal at least in a portion, is recessed toward the side away from the bottom cover, dividing the refrigerant flow path; as well as The boss portion protrudes toward the bottom cover at the junction of the venting recess and the refrigerant recess, at a position closer to the venting recess than the sealing member. The bottom cover is threadedly fixed to the boss portion.

2. The energy storage pack according to claim 1, wherein, The bottom surface of the main body also has a connecting hole on the side facing the bottom cover. The connecting hole is covered by a breathable membrane, connecting the storage space for accommodating multiple energy storage devices with the airflow path. The airflow path forms an exhaust path for discharging the gas generated by the plurality of energy storage devices.

3. The energy storage pack according to claim 2, wherein, The membrane is covered from the outer surface side by a protective shield. The protective cover and the bottom cover are threaded together and fixed to the boss portion of the main body.

4. The energy storage pack according to claim 1, wherein, The bottom cover has a stepped portion at a position opposite to the boss portion of the main body.

5. The energy storage pack according to claim 4, wherein, The protruding part abuts against the stepped part of the bottom cover.

6. The energy storage pack according to claim 1, wherein, The bottom surface of the main body also has an abutting surface on the side facing the bottom cover. The contact surface is located between the refrigerant recess and the sealing element, protruding towards the bottom cover and abutting against the bottom cover. The protrusion protrudes beyond the abutting surface of the bottom cover side.

7. The energy storage pack according to claim 1, wherein, The boundary portion is located opposite the storage space that houses multiple energy storage devices.

8. The energy storage pack according to claim 7, wherein, The bottom surface of the main body has the following characteristics on the side facing the storage space: A mounting surface on which multiple energy storage devices are mounted; as well as The recessed portion is recessed from the mounting surface on the bottom cover side. The boundary portion is located opposite to the recessed portion.

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