Battery packs and battery packs

Abstract

The present invention belongs to an on-vehicle battery pack field and addresses the technical problem of providing an on-vehicle battery pack having a high level of safety irrespective of a use environment thereof.　The present invention pertains to a battery pack formed by storing a battery assembly inside a metal battery case, the battery pack comprising, in the bottom of the battery case: a partitioning part for partitioning the inner surface of the bottom into a plurality of regions; and an insulating part for insulating at least a central-side region in the bottom. The battery assembly comprises: a laminate body formed by alternately laminating secondary batteries and spacers such that the secondary batteries are located at both ends thereof; and end spacers located at both ends of the laminate body. In the bottom of each of the end spacers, a protruding part is formed to protrude to the central side, of the lower surface of the battery assembly, in the lamination direction of the battery assembly. The tip of the protruding part is located on a side closer to the central side, of the lower surface of the battery assembly, in the lamination direction of the battery assembly, as compared with the installation site of the partitioning part.

Description

[Technical Field]

[0001] The present invention relates to an in-vehicle battery pack and a battery assembly incorporated into the battery pack. [Background technology]

[0002] Many electric vehicles, such as battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs), are equipped with secondary batteries as a power supply source that supplies the necessary power to the motor. Specific examples of such in-vehicle secondary batteries include lithium-ion batteries, sodium-ion batteries, and various all-solid-state batteries.

[0003] The driving performance of an electric vehicle, such as driving force and cruising range, depends on the capacity of the secondary battery installed as the power supply. In other words, in order for the various electric vehicles described above to achieve good driving performance, it is essential to install a high-capacity secondary battery. However, when using the various secondary batteries described above as a power supply source, increasing the size of the battery to obtain a high-capacity in-vehicle secondary battery poses challenges in terms of battery life, safety, and the like. For this reason, when using the various secondary batteries described above as a power supply source for an electric vehicle, it is common to bundle multiple batteries together to form a battery pack. Regarding such a battery pack, a technology described in Patent Document 1, for example, is known. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-220218 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the battery pack has an exoskeleton structure in which a plurality of stacked batteries are supported by a metal support. Furthermore, to ensure sufficient rigidity and vibration absorption, the battery pack is mounted in a vehicle in a state housed in a metal battery casing. In this case, the battery pack is usually attached to the battery casing using various metal fixing members such as bolts and washers, and is fixed inside the battery casing.

[0006] The various electric vehicles described above can be used in a variety of environments. For example, when these electric vehicles are used in an environment with a large temperature difference between the inside and outside of the vehicle or in a humid environment, water vapor in the air may condense and adhere to the surfaces of metal or resin components, such as the battery casing and support, causing condensation. Here, the battery pack and the battery casing are typically not in direct contact with each other because an insulating member, such as a resin, is interposed between them. However, the battery pack and the battery casing are fastened to each other by a conductive metal fastening member. Therefore, if water droplets formed on the surfaces of metal or resin components, such as the battery casing and support, drip and reach the fastening points between the battery pack and the battery casing, the normally insulated battery pack and the battery casing may become electrically conductive through the water droplets, resulting in a short circuit.

[0007] In view of the above problems, an object of the present invention is to provide an in-vehicle battery pack and battery assembly that are highly safe regardless of the usage environment. [Means for solving the problem]

[0008] The battery pack according to the present invention has an assembled battery housed inside a metal battery casing, and three coordinate axes in a three-dimensional orthogonal coordinate system are defined as the up-down direction, the stacking direction of the assembled battery, and the width direction of the assembled battery, respectively. The battery casing bottom is provided with a first fixing portion that is arranged on the inner surface of the bottom in an area facing the underside of the assembled battery, and that fixes the assembled battery upward; partition portions that divide the inner surface of the bottom into a plurality of areas; and an insulating portion that insulates at least a central area of ​​the bottom among the plurality of partitioned areas. The assembled battery is made of secondary batteries and spacers that are alternately stacked, and includes a stacked body having secondary batteries at both ends and end spacers that are respectively arranged on both ends of the stacked body. Second fixing portions that fix the assembled battery downward are provided on the underside of the assembled battery near both ends, and the first fixing portion and the second fixing portion are arranged coaxially opposite each other, and the bottom of the spacer is arranged to be in contact with one of the adjacent secondary batteries. the spacer and end spacer have the following (1) or (2): (1) the bottom of the end spacer extends in the stacking direction of the battery pack so as to further cover the underside of the bottom of the spacer, and the upper surface of the bottom of the end spacer and the lower surface of the bottom of the spacer face each other in the vertical direction; (2) the bottom of the end spacer extends in the stacking direction of the battery pack so as to cover the underside of one of the adjacent secondary batteries, and the bottom of the spacer extends in the stacking direction of the battery pack so as to further cover the underside of the bottom of the end spacer, and the upper surface of the bottom of the spacer and the lower surface of the bottom of the end spacer face each other in the vertical direction; and the bottom of the end spacer is formed with a protrusion that protrudes toward the center of the underside of the battery pack in the stacking direction of the battery pack, and the tip of the protrusion is located closer to the center of the underside of the battery pack than the installation location of the partition in the stacking direction of the battery pack.

[0009] The battery assembly according to the present invention is incorporated into a battery pack and is made of alternately stacked secondary batteries and spacers, and includes a stack having secondary batteries at both ends, and end spacers disposed at both ends of the stack, with three coordinate axes in a three-dimensional orthogonal coordinate system defined as the up-down direction, the stacking direction of the battery assembly, and the width direction of the battery assembly, respectively. Fixing portions for fixing the battery assembly downward are provided near both ends of the battery assembly on the underside of the battery assembly, and the bottom of the spacer extends in the stacking direction of the battery assembly so as to cover the underside of one of the adjacent secondary batteries, and the spacer and end spacer have the following (1) or (2): (1) the bottom of the end spacer is arranged so as to further cover the underside of the bottom of the spacer. (2) the bottom of the end spacer extends in the stacking direction of the battery pack so as to cover the underside of one of the adjacent secondary batteries, and the bottom of the spacer extends in the stacking direction of the battery pack so as to further cover the underside of the bottom of the end spacer, and the top surface of the bottom of the spacer and the underside of the bottom of the end spacer face each other in the vertical direction, and a protrusion is formed on the bottom of the end spacer that protrudes toward the center of the underside of the battery pack in the stacking direction of the battery pack, and the tip of the protrusion is located closer to the center of the underside of the battery pack than the installation location of the fixing part in the stacking direction of the battery pack. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an in-vehicle battery pack and battery assembly that are highly safe regardless of the usage environment. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing the appearance of a battery pack according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing the configuration of the battery pack according to the embodiment. [Figure 3] FIG. 1 is a perspective view showing the appearance of a battery pack according to an embodiment. [Figure 4] FIG. 1 is an exploded perspective view showing a configuration of a battery pack according to an embodiment. [Figure 5] FIG. 1 is a schematic diagram illustrating a problem in the prior art. [Figure 6] FIG. 2 is a perspective view showing the appearance of a protrusion of the battery pack according to the embodiment. [Figure 7] 5A and 5B are schematic diagrams showing the relative positional relationship of protrusions of the battery pack according to the embodiment; [Figure 8] FIG. 2 is a perspective view showing the appearance of an end spacer of the battery pack according to the embodiment. [Figure 9] FIG. 10 is a perspective view showing the appearance of an end spacer of a battery pack according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following description, the three coordinate axis directions in the three-dimensional orthogonal coordinate system are the up-down direction, the stacking direction of the battery pack, and the width direction of the battery pack, respectively. In the following description, the up-down direction is assumed to be the vertical direction.

[0013] Fig. 1 is a perspective view showing the appearance of a battery pack 1 according to this embodiment. Fig. 2 is an exploded perspective view showing the configuration of the battery pack 1. Figs. 1 and 2 show the battery pack 1 and the relative positions of its components. The battery pack 1 shown in Fig. 1 is mounted as a power supply source in the various electric vehicles (not shown) mentioned above.

[0014] As shown in Fig. 2, this battery pack 1 has a battery assembly 11 housed inside a hollow box-shaped metal battery casing 12. In Fig. 2, two battery assemblies (11a, 11b) are housed inside the battery casing 12, but the number of battery assemblies 11 housed inside the battery casing 12 can be changed as appropriate.

[0015] As shown in FIG. 2, the battery casing 12 is composed of a metal battery casing body 12b in the shape of a rectangular cylinder with a bottom, and a flat metal lid 12a. A cooling duct 41 insertion hole 21 is formed near one edge of the outer periphery of the lid 12a. This cooling duct 41 insertion hole 21 is for inserting a cooling duct 41 for exhausting heat that is attached to a fixing member that fixes the battery pack (11a, 11b). Because the cooling duct 41 insertion hole 21 is provided in the lid 12a, when the lid 12a is closed with the battery pack (11a, 11b) housed inside the battery casing body 12b, the lid 12a can close the open end of the battery casing body 12b without interfering with the cooling duct 41. This seals the interior of the battery casing 12.

[0016] In the battery pack 1, the battery casing 12 and the battery assembly 11 are fixed to each other with various metallic fastening members such as conductive bolts and washers. Therefore, as shown in FIG. 2, holes 22 are provided on the inner surface of the bottom of the battery casing main body 12b. These holes 22 serve as fastening parts (hereinafter also referred to as "first fastening parts") that fasten the battery casing 12 to the battery assembly 11. These holes 22 are located in the area facing the lower surface of the battery assembly 11, near both ends of the battery assembly 11 in the stacking direction. In other words, in FIG. 2, the holes 22 are provided so that their axial direction is vertical. The holes 22 may be tapped for directly fastening bolts. Furthermore, a nut for fastening the bolt may be provided coaxially with the holes 22 on either surface of the bottom of the battery casing main body 12b. Furthermore, the holes 22 may or may not communicate the interior space of the battery casing 12 with the exterior space.

[0017] Note that fixing portions for fixing the battery casing main body 12b and the battery assembly 11 with various fixing members such as bolts and washers are also provided on the underside of the battery assembly 11 near both ends in the stacking direction, as holes or tapped holes, for example. In the following description, these fixing portions provided on the battery assembly 11 side are also referred to as second fixing portions. The second fixing portions are installed coaxially opposite the first fixing portions when the battery assembly 11 is installed in the battery casing 12. This ensures that the underside of the battery assembly 11, which is located above, and the inner surface of the bottom of the battery casing 12, which is located below, are properly fixed in the vertical direction.

[0018] That is, the holes 22, which are the first fixing portions, are arranged in the area of ​​the bottom of the battery casing 12 facing the underside of the battery pack 11, at positions coaxial with the second fixing portions, in other words, near positions corresponding to both ends of the underside of the battery pack 11 in the stacking direction. In Fig. 2, three holes 22 are provided at equal intervals in the width direction of the battery packs (11a, 11b) in the area of ​​the bottom of the battery casing main body 12b facing the underside of each battery pack (11a, 11b).

[0019] The specific configuration, shape, installation material, arrangement, number, etc. of the first fixing portion provided on the bottom of the battery casing 12 and the second fixing portion provided on the underside of the battery pack 11 can be changed as appropriate.

[0020] An insulating section is provided on the inner surface of the bottom of the battery casing 12, insulating at least a region of the inner surface of the bottom of the battery casing 12 that is closer to the center than the location of the partition section 32, which will be described later. In FIG. 2, an insulating case 13 is disposed inside the battery casing main body 12b. This insulating case 13 is an insulating resin container in the shape of a rectangular cylinder with a bottom. The insulating case 13 shown in FIG. 2 is attached to the inside of the battery casing main body 12b so that its outer surface is in close contact with the inner surface of the battery casing main body 12b. As a result, most of the inner surface of the bottom of the battery casing 12 is insulated.

[0021] That is, the battery pack 11 is installed in the battery housing 12 while being housed inside the insulating case 13. Therefore, the lower surface of the battery pack 11 and the inner surface of the bottom of the battery housing 12 are mostly insulated by the insulating case 13 interposed therebetween.

[0022] The bottom of the insulating case 13 shown in FIG. 2 is provided with a substantially rectangular opening 31, the long side of which is the width direction of the assembled batteries (11a, 11b). This opening 31 is formed by cutting out a portion of the bottom of the insulating case 13 for the purpose of inserting fixing members that fix each assembled battery (11a, 11b) to the battery housing body 12b. Therefore, when the insulating case 13 is attached inside the battery housing body 12b, the portion of the bottom of the battery housing body 12b that overlaps with the opening 31 in the bottom of the insulating case 13, i.e., the area near the hole 22, which serves as the first fixing portion, is not insulated, and the inner surface of the battery housing body 12b, which is made of a conductive metal, is exposed. The specific position, size, area, shape, etc. of the opening 31 can be changed as appropriate.

[0023] Furthermore, on the inner surface of the bottom of the insulating case 13 shown in FIG. 2, i.e., on the inner surface of the bottom of the battery casing 12, ridge-like partitions 32 protruding from the inner surface are provided in the width direction of the assembled battery (11a, 11b). These partitions 32 divide the inner surface of the bottom of each adjacent battery casing 12 into multiple regions in the stacking direction of the assembled batteries (11a, 11b). Specifically, the partitions 32 shown in FIG. 2 are formed by applying or attaching a water-repellent sealant made of a foamed resin to the inner surface of the bottom of the insulating case 13. That is, the partitions 32 are water-repellent. Furthermore, the partitions 32 shown in FIG. 2 extend in the width direction of the assembled battery 11 along the long side of the substantially rectangular opening 31 that is closer to the center of the bottom of the insulating case 13, in other words, the long side closer to the center of the area facing the underside of the assembled battery 11. As a result, the partition 32 is disposed within the battery casing 12 so as to separate the area including the ground surface of the battery pack 11 from the area including the opening 31 on the inner surface of the bottom of the insulating case 13 .

[0024] When the battery pack 11 is attached to the battery casing 12, the lower surface of the battery pack 11 comes into contact with the upper surface of the partition 32, which presses it downward and causes it to deform so as to be crushed in the vertical direction. Therefore, the upper surface of the partition 32 is in close contact with the lower surface of the battery pack 11 when the battery pack 11 is attached to the battery casing 12. As a result, the partition 32 functions as a partition wall that separates the two spaces on either side of it in the stacking direction of the battery pack 11, i.e., in the width direction of the partition 32.

[0025] In this embodiment, the partition 32 shown in FIG. 2 is described as a foamed resin sealant applied or attached to the bottom of the insulating case 13. However, the partition 32 may be any water-repellent material fixed to the insulating portion. That is, the partition 32 may be a non-foamed resin material or a rubber material. For example, the partition 32 may be made of ethylene propylene diene monomer (EPDM) rubber, or may be made of other olefin-based resins such as thermoplastic polyolefin (TPO) or polyethylene (PE), or may be made of urethane-based resins such as thermoplastic polyurethane (TPU). The partition 32 may be a separate material from the insulating portion and fixed to the insulating portion by coating, pasting, or the like, or may be integrally molded with the insulating portion as the same material.

[0026] 2, the partitions 32 are described as being tape-shaped members provided in the width direction of the battery pack (11a, 11b). However, the layout shape of the partitions 32 in the horizontal plane may be, for example, linear, planar, or dot-shaped.

[0027] In the present embodiment, the insulating case 13 is attached to the inside of the battery housing main body 12b, thereby insulating most of the inner surface of the bottom of the battery housing 12. However, the insulating portion does not have to be provided so as to cover most of the inner surface of the bottom of the battery housing 12. For example, the insulating portion may be provided only in a partial area of ​​the bottom of the battery housing 12, including at least an area toward the center of where the partitions 32 are located, i.e., an area facing the lower end of the battery pack 11.

[0028] Next, the battery pack 11 incorporated in the battery pack 1 will be described with reference to Figs. 3 and 4. Fig. 3 is a perspective view showing the appearance of the battery pack 11. Fig. 4 is an exploded perspective view showing the configuration of the battery pack 11. The battery pack 11 shown in Figs. 3 and 4 corresponds to one of the two battery packs (11a, 11b) shown in Fig. 2.

[0029] As shown in FIG. 4, the battery pack 11 is made up of a plurality of secondary batteries 110a, 110b,..., 110n (hereinafter collectively referred to as "secondary batteries 110" when referring to them collectively or when no distinction is made) and one or more spacers 120a, 120b,..., 120n (hereinafter collectively referred to as "spacers 120" when referring to them collectively or when no distinction is made) interposed between each pair of adjacent secondary batteries 110, stacked alternately, with one end spacer 130 disposed at each end in the stacking direction.

[0030] Metal end plates 220 are fixed to the two end spacers 130 with bolts 230 from the outside of the battery pack 11 in the stacking direction. In addition, a metal fixing part (not shown) coated with insulating resin and having a second fixing portion on its underside is also attached to the end spacers 130. In other words, by configuring the battery pack 11 in this way, the battery pack 11 has a structure in which the multiple secondary batteries 110 stacked with the spacers 120 interposed therebetween are sandwiched between two end spacers 130, one at each end, in the stacking direction.

[0031] Metallic side rails (210a, 210b) are attached to both sides of the battery pack 11 in the width direction. Furthermore, an upper structure 240 is attached above the battery pack 11. The upper structure 240 includes metallic members such as bus bars 242 for electrically connecting the multiple secondary batteries 110, covers (241a, 241b) for protecting the bus bars 242, and a gas exhaust duct 243. These members also serve as an exoskeleton to ensure that the battery pack 11 has sufficient rigidity.

[0032] The secondary battery 110 is a secondary battery in which an electrode body that serves as both an electricity storage element and a power generation element is sealed inside. The secondary battery 110 may be, for example, a lithium ion battery, a sodium ion battery, or a secondary battery that uses another type of material as the positive electrode active material. Furthermore, the secondary battery 110 may include an electrolyte solution or a solid electrolyte. In other words, the secondary battery 110 may be an all-solid-state battery. Of course, the secondary battery 110 may also be a nickel-metal hydride battery.

[0033] When the secondary battery 110 is a lithium ion battery, the positive electrode material may be any of various lithium alloys such as lithium cobalt oxide (LiCoO), lithium manganese oxide (LiMnO), lithium nickel oxide (LiNiO), and lithium iron phosphate (LiFePO), or may be a lithium alloy such as a so-called ternary lithium (LiNiCoMnO) or NCA-based lithium (LiNiCoAlO), or may be lithium metal.

[0034] The spacers 120 are components made of, for example, insulating resin. One spacer 120 is interposed between each pair of adjacent secondary batteries 110. This ensures that each secondary battery 110 is separated by a spacer 120 to provide an appropriate insulation distance between the adjacent secondary batteries 110. Therefore, the thickness of the spacers 120, i.e., the dimensions of each spacer 120 in the stacking direction of the battery pack 11, need only ensure an appropriate insulation distance between each pair of adjacent secondary batteries 110. Therefore, the spacers 120 may be made of an aluminum alloy whose surface is covered with an oxide film by, for example, anodizing.

[0035] Furthermore, the bottom of one surface of the spacer 120 in the stacking direction of the battery pack 11 extends in the stacking direction of the battery pack 11 so as to cover the underside of one adjacent secondary battery 110. That is, the bottom of the spacer 120 has an upper surface that faces the underside of the secondary battery 110. Furthermore, the upper surface of the bottom of this spacer 120 also faces the underside of the bottom of another spacer 120 adjacent to it across the secondary battery 110. That is, the upper surface of the bottom of this spacer 120 and the underside of the bottom of the other adjacent spacer 120 face each other in the vertical direction.

[0036] The bottom of the other surface of the spacer 120 in the stacking direction of the battery pack 11 extends in the stacking direction of the battery pack 11 so as to cover the lower surface of the adjacent secondary battery 110 on the opposite side. That is, the bottom of the spacer 120 has an upper surface that faces the lower surface of the secondary battery 110. Furthermore, the lower surface of the bottom of this spacer 120 also has a facing portion with the upper surface of the bottom of another adjacent spacer 120. That is, the lower surface of the bottom of this spacer 120 and the upper surface of the bottom of the other adjacent spacer 120 face each other in the vertical direction.

[0037] The end spacers 130 are also components made of, for example, insulating resin. One end spacer 130 is attached to each end in the stacking direction of the multiple secondary batteries 110 stacked with the spacers 120 interposed therebetween. This ensures that each of the secondary batteries 110 arranged at both ends maintains an appropriate insulation distance from the metal end plates 220 and fixing parts attached to each end spacer 130. That is, the thickness of the end spacers 130, i.e., the dimensions of each end spacer 130 in the stacking direction of the battery pack 11, need only ensure an appropriate insulation distance between the metal parts and the adjacent secondary batteries 110. Therefore, the end spacers 130 may be made of an aluminum alloy whose surface is covered with an oxide film by, for example, anodizing.

[0038] In addition, the spacers 120 and end spacers 130 also have portions interposed between the side surfaces of each secondary battery 110 and the inner side surfaces of the side rails (210a, 210b) arranged on both sides of the battery pack 11 in the width direction, thereby ensuring an appropriate insulation distance.

[0039] The bottom of the end spacer 130 disposed at one end of the battery pack 11 in the stacking direction extends in the stacking direction of the battery pack 11 so as to cover the lower surface of the bottom of the spacer 120 which covers the lower surface of the adjacent secondary battery 110. That is, the bottom of the end spacer 130 has an upper surface facing the lower surface of the bottom of the spacer 120. That is, the upper surface of the bottom of the end spacer 130 and the lower surface of the bottom of the spacer 120 face each other in the vertical direction.

[0040] Furthermore, the bottom of the end spacer 130 disposed at the other end of the one side extends in the stacking direction of the battery pack 11 so as to cover the lower surface of the adjacent secondary battery 110. The bottom of another adjacent spacer 120 extends in the stacking direction of the battery pack 11 so as to further cover the lower surface of the bottom of the end spacer 130. That is, the bottom of the end spacer 130 has a lower surface that faces the upper surface of the bottom of the spacer 120. That is, the lower surface of the bottom of the end spacer 130 and the upper surface of the bottom of the spacer 120 face each other in the vertical direction.

[0041] The facing area (described in detail below) between the upper surface of the bottom of the end spacer 130 and the lower surface of the bottom of the spacer 120 is formed across the entire width of the battery pack 11. A partition section 32 is provided below the facing area. That is, the facing area and the partition section 32 are arranged approximately parallel to each other. The upper end surface of the partition section 32 is in close contact with the lower end surfaces of the spacer 120 and the end spacer 130.

[0042] As mentioned above, condensation may occur on the surfaces of metal components such as the battery housing 12 and side rails 210, causing water droplets to adhere and drip downward. In such cases, a problem that arises in a battery pack of the prior art is shown in Figure 5. Figure 5 is a schematic diagram illustrating the problem in the prior art. As shown in Figure 5, in a battery pack of the prior art, condensed water 300 that has turned into droplets flows down through the gaps between the secondary battery 110 and the spacer 120 or end spacer 1300, reaches the bottom of the battery pack, and then drips onto the bottom of the battery housing main body 12b.

[0043] The configuration of the battery pack of the prior art is generally similar to the configuration of the battery pack 1 of the present embodiment described above. That is, in the battery pack of the prior art, most of the inner surface of the bottom of the battery housing main body 12b is insulated by the insulating case 13. In addition, as shown in FIG. 5 , a ridge-shaped partition 32 that functions as a partition wall is provided on the inner surface of the bottom of the battery housing main body 12b in the width direction of the assembled battery. Therefore, on the inner surface of the bottom of the battery housing main body 12b, two types of regions with different properties exist, separated by the location of the partition 32. Of these, the region closer to the center than the location of the partition 32 is entirely insulated by the insulating case 13. On the other hand, the region closer to the outer edge than the location of the partition 32 has a region that overlaps with the opening 31 of the insulating case 13. In this region overlapping with the opening 31 of the insulating case 13, the inner surface of the battery housing main body 12b made of conductive metal is exposed. Furthermore, holes 22, which are first fixing portions for fixing the battery pack and battery casing 12, are disposed in the region overlapping with opening 31 of insulating case 13. In other words, the battery pack of the prior art has a problem in that if condensed water 300 drips into a non-insulated portion present in the region on the outer edge side of the location of partition 32, for example, through opposing portion 150 between the upper surface of the bottom of end spacer 1300 and the lower surface of the bottom of spacer 120, the normally insulated battery pack and battery casing 12 may become conductive via condensed water 300, potentially causing a short circuit.

[0044] Therefore, in the battery pack 1 of this embodiment, as shown in FIG. 4, a protrusion 140 is formed on the bottom of the end spacer 130 of the battery pack 11, protruding toward the center of the underside of the battery pack 11 in the stacking direction of the battery pack 11.

[0045] 6 and 7 are schematic diagrams illustrating an overview of the protrusion 140 of the battery pack 11 according to this embodiment. FIG. 6 is a perspective view illustrating the appearance of the protrusion 140. FIG. 7 is a side view illustrating the relative positional relationship of the protrusion 140. As shown in FIG. 6, condensed water 300 reaches the bottom of the battery pack 11 through a facing area 150 between the upper surface of the bottom of the end spacer 130 and the lower surface of the bottom of the spacer 120. The condensed water 300 then flows down the surface of the protrusion 140, the base end of which is located below the facing area 150, and drips downward from the tip 160 of the protrusion 140. The protrusion 140 is disposed so that its lower end surface is in contact with the upper end surface of the partition 32. As shown in FIG. 7, the tip 160 of the protrusion 140 is disposed above an insulating region on the bottom of the battery casing main body 12b, closer to the center than the location of the partition 32, in the stacking direction of the battery pack 11. Therefore, the condensed water 300 drips into the insulating region. That is, in the battery pack 1 of this embodiment, the protrusion 140 is provided on the lower end side of the end spacer 130, so that the dripping condensed water 300 can be reliably guided to the insulating region at the bottom of the battery casing main body 12b, which is closer to the center in the stacking direction of the battery pack 11 than the location of the partition 32. As a result, a short circuit caused by the condensed water 300 dripping into the non-insulated region is reliably prevented.

[0046] Fig. 8 is a perspective view showing the appearance of the end spacer 130 of the battery pack 11 according to this embodiment. As shown in Fig. 8, the protrusion 140 is integrally molded on the lower side of the end spacer 130 made of insulating resin. In Fig. 8, a pair of protrusions (140a, 140b) is provided, one on each side of the end spacer 130 in the width direction.

[0047] 6 and 8, the protrusion 140 has a tapered longitudinal cross section in the stacking direction of the battery pack 11, with the thickness decreasing in the vertical direction toward the tip 160. Furthermore, the protrusion 140 has a substantially L-shaped longitudinal cross section in the width direction of the battery pack 11. That is, the protrusion 140 has a substantially horizontal bottom extending in the stacking direction of the battery pack 11 and a substantially vertical outer wall extending upward from one edge of the bottom. Thus, the inside of the space roughly defined by the bottom, the outer wall, and the side wall facing the outer wall serves as a passage for the condensed water 300, so that the condensed water 300 can be reliably guided from the base end to the tip 160.

[0048] In the present embodiment, the protrusion 140 has been described as having a substantially L-shaped cross section in the width direction of the battery pack 11, as shown in FIGS. 6 and 8 . However, the specific cross-sectional shape of the protrusion 140 in the width direction of the battery pack 11 may be any shape that can reliably guide the condensed water 300 from the base end side to the tip end 160 side. For example, the cross-sectional shape of the protrusion in the width direction of the battery pack may be substantially U-shaped. Furthermore, for example, the protrusion may be formed as a hollow cylinder having a cross-sectional shape such as a substantially circular ring, a substantially elliptical ring, or a substantially polygonal ring in the width direction of the battery pack. Furthermore, the protrusion may be formed as a solid member having a cross-sectional shape that is substantially polygonal in the width direction of the battery pack.

[0049] Furthermore, it is sufficient that the protrusion 140 can reliably guide the condensed water 300 dripping from its tip 160 to an insulating region on the bottom of the battery casing main body 12b that is closer to the center than the location of the partition 32. In other words, the specific dimensions of the protrusion 140, such as the thickness of the bottom and outer wall and the length of the protrusion 140 in the stacking direction of the battery pack 11, may be set arbitrarily as long as the intended purpose can be achieved.

[0050] In addition, in this embodiment, the protrusions 140 are described as being integrally molded with the resin end spacer 130. However, the protrusions 140 may be installed by attaching a separate member to the end spacer 130. Furthermore, the entire protrusions 140 do not have to be made of resin. In other words, it is sufficient that at least the portions of the surface of the protrusions 140 that come into contact with the condensed water 300 are coated with resin.

[0051] In addition, in the present embodiment, as shown in Fig. 8, a pair of protrusions (140a, 140b) is provided on each side of the end spacer 130 in the width direction. However, for example, as shown in Fig. 9, the end spacer 330 may be provided with a protrusion 440 formed to cover the entire lower area of ​​the end spacer 330. In this case, the bottom of the protrusion 440 may be formed across the entire width of the end spacer 330. This positions the protrusion 440 above the partition 32 over the entire width of the battery pack, so that the condensed water 300 can be more reliably guided to the insulating region of the bottom of the battery housing main body 12b that is closer to the center than the location where the partition 32 is located.

[0052] In addition, in this embodiment, the protrusion 140 is described as being provided on the end spacer 130. However, in addition to or instead of the protrusion 140 provided on the end spacer 130, a second protrusion different from the protrusion 140 may be provided on other components, such as the spacer 120, the secondary battery 110, the end plate 220, or the side rail 210. In this case, the second protrusion may be integrally molded with these components or formed separately and attached to these components. For example, when a second protrusion is formed on a spacer, the tip of the second protrusion may be positioned closer to the center of the bottom surface of the battery assembly than the facing portion formed by the upper surface of the bottom of the spacer and the lower surface of the bottom of an adjacent spacer overlapping in the vertical direction in the stacking direction of the battery assembly. In such a case, it is not necessary to provide a second protrusion on the bottom of the adjacent spacer. That is, in this case, the second protrusion may be provided only on some of the spacers. This prevents a short circuit between the battery pack and the battery housing 12, even if, for example, the bottom of the insulating case 13 is damaged, exposing the surface of the metal battery housing body 12b from the damaged area and causing condensed water 300 to drip onto the exposed surface of the battery housing body 12b. Note that it may be determined as appropriate which spacer the second protrusion is to be attached to.

[0053] When the protrusion 140 is provided on the end spacer 130, or when the second protrusion is provided on a member such as the spacer 120, the secondary battery 110, the end plate 220, or the side rail 210, the surface where the protrusion 140 or the second protrusion is provided is preferably coated with resin. In addition, this resin is preferably a water-repellent insulating resin. This can prevent condensation from forming on the surface of the protrusion 140 or the second protrusion.

[0054] For example, a groove, a pipe, or a combination thereof may be formed integrally or separately in the region of the insulating portion that is located below the tip 160 of the protrusion 140. This prevents the condensed water 300 that drips from the tip 160 of the protrusion 140 from accumulating on the surface of the insulating portion, and allows the condensed water 300 to be properly drained.

[0055] In this embodiment, as shown in Figures 5 and 6, the partition 32 is described as a ridge-shaped member formed by applying or attaching a water-repellent sealant made of foamed resin to the inner surface of the bottom of the insulating case 13. However, the partition may also be formed, for example, by a step formed in the bottom of the battery housing body or the insulating case installed inside the battery housing body. In this case, the step may be formed, for example, by forming the bottom of the battery housing so that the center is lower than the location of the fixing part in the stacking direction of the battery pack. This allows condensed water 300 dripping near the non-insulated area where the hole 22, which is the first fixing part, is located to flow to a lower area, thereby preventing a short circuit caused by condensed water 300 dripping into the non-insulated area.

[0056] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0057] (1) The battery pack 1 is configured by housing an assembled battery 11 inside a metal battery casing 12, and the three coordinate axes in a three-dimensional orthogonal coordinate system are respectively the up-down direction, the stacking direction of the assembled battery 11, and the width direction of the assembled battery 11. The battery casing 12 has a bottom portion provided with a hole 22 as a first fixing portion that fixes the assembled battery 11 upward and is disposed on the inner surface of the bottom in an area facing the underside of the assembled battery 11, a partition portion 32 that divides the inner surface of the bottom into a plurality of areas, and a partition portion 32 that insulates at least the central area of ​​the bottom from the plurality of divided areas. The battery pack 11 is made up of alternately stacked secondary batteries 110 and spacers 120, and includes a stack having secondary batteries 110 at both ends and end spacers 130 arranged at both ends of the stack. Second fixing portions for fixing the battery pack 11 downward are provided on the underside of the battery pack 11 near both ends of the battery pack 11. The holes 22 as the first fixing portions and the second fixing portions are provided coaxially opposite each other, and the bottom of the spacer 120 covers the underside of one of the adjacent secondary batteries 110. The spacer 120 and the end spacer 130 have the following (1) or (2): (1) the bottom of the end spacer 130 extends in the stacking direction of the battery pack 11 so as to cover the lower surface of the bottom of the spacer 120, and the upper surface of the bottom of the end spacer 130 and the lower surface of the bottom of the spacer 120 face each other in the vertical direction; (2) the bottom of the end spacer 130 extends in the stacking direction of the battery pack 11 so as to cover the lower surface of one of the adjacent secondary batteries 110, and The bottom of the spacer 120 extends in the stacking direction of the battery pack 11 so as to cover the underside of the bottom of the end spacer 130, the upper surface of the bottom of the spacer 120 and the underside of the bottom of the end spacer 130 face each other in the vertical direction, and the bottom of the end spacer 130 is formed with a protrusion 140 that protrudes toward the center of the underside of the battery pack 11 in the stacking direction of the battery pack 11, and the tip of the protrusion 140 is located closer to the center of the underside of the battery pack 11 than the installation location of the partition 32 in the stacking direction of the battery pack 11. This ensures that the condensed water 300 drips onto the insulating parts, preventing short circuits that would occur if the condensed water 300 dripped into non-insulated areas.

[0058] (2) The partition 32 is configured such that a sealant is disposed on the insulating portion, thereby effectively stopping dripping condensed water 300 on the insulating portion.

[0059] (3) The partitioning portion 32 may be made of the same material as the insulating portion and may be integrally molded with the insulating portion, which makes it easier to manufacture the battery pack 1.

[0060] (4) The partition 32 may be formed by a step formed in the bottom of the battery casing. In this case, the step may be formed by forming the bottom of the battery casing so that the center side is lower in the stacking direction of the battery pack 11 than the location of the hole 22, which is the first fastening part. In this case, condensed water 300 dripping near the non-insulated area where the hole 22, which is the first fastening part, is located flows to the lower area, thereby preventing a short circuit caused by the condensed water 300 dripping into the non-insulated area.

[0061] (5) A passage for dripping condensed water 300 is formed from the opposing portion 150 between the upper surface of the bottom of the end spacer 130 and the lower surface of the bottom of the spacer 120 to the tip 160 of the protrusion 140. This configuration allows the dripping condensed water 300 to be effectively guided downward.

[0062] (6) The battery pack 11 may further include side rails 210 attached to both sides in the width direction and end plates 220 attached to the outside of the end spacers 130 in the stacking direction. In this case, a second protrusion that protrudes in the stacking direction of the battery pack may be formed integrally or separately on the bottom of at least one of the spacers, side rails, end plates, and secondary batteries. In this case, the condensed water 300 can be more effectively dripped downward.

[0063] (7) The second protrusion may be formed on the bottom of one spacer, and one main surface of the bottom of the spacer on which the second protrusion is formed and one main surface of the bottom of another spacer 120 adjacent to the spacer via the secondary battery 110 may form a facing portion where the surfaces face each other in the vertical direction, and the second protrusion may be disposed below the facing portion. In this case, even if, for example, the bottom of the insulating case 13 is damaged and the surface of the metal battery housing 12 is exposed from the damaged portion and condensed water 300 drips onto the exposed surface of the battery housing 12, a short circuit between the battery pack and the battery housing 12 can be prevented.

[0064] (8) The protrusion 140 has a vertical cross-sectional shape in the stacking direction of the battery pack 11 that is tapered so that the thickness decreases in the vertical direction toward the tip 160. This configuration ensures that the condensed water 300 can be reliably guided toward the tip 160.

[0065] (9) The protrusion 140 has a substantially horizontal bottom extending in the stacking direction of the battery pack 11 and a substantially vertical outer wall extending upward from one edge of the bottom. This configuration ensures that condensed water 300 can be reliably guided toward the tip 160, even when the amount of condensed water 300 is large.

[0066] (10) The base end of the protrusion 140 is located below the opposing portion 150 between the upper surface of the bottom of the end spacer 130 and the lower surface of the bottom of the spacer 120. This arrangement allows the condensed water 300 that reaches the opposing portion 150 to be effectively guided toward the tip 160.

[0067] (11) The assembled battery 11 is incorporated into the battery pack 1 and is made of alternately stacked secondary batteries 110 and spacers 120. The assembled battery 11 comprises a stack of secondary batteries 110 at both ends and end spacers 130 disposed at both ends of the stack. The three coordinate axes in a three-dimensional orthogonal coordinate system are respectively the up-down direction, the stacking direction of the assembled battery 11, and the width direction of the assembled battery 11. Fixing portions for fixing the assembled battery 11 downward are provided on the underside of the assembled battery 11 near both ends of the assembled battery 11. The bottom of the spacer 120 extends in the stacking direction of the assembled battery 11 so as to cover the underside of one of the adjacent secondary batteries 110. The spacer 120 and the end spacer 130 have the following (1) or (2): (1) the bottom of the end spacer 130 is fixed to the assembled battery 11 so as to further cover the underside of the bottom of the spacer 120. (1) The end spacer 130 extends in the stacking direction of the assembled battery 11 so as to cover the underside of one of the adjacent secondary batteries 110, and the bottom of the spacer 120 extends in the stacking direction of the assembled battery 11 so as to further cover the underside of the bottom of the end spacer 130, and the upper surface of the bottom of the spacer 120 and the underside of the bottom of the end spacer 130 face each other in the vertical direction, and a protrusion 140 is formed on the bottom of the end spacer 130, protruding toward the center of the underside of the assembled battery 11 in the stacking direction of the assembled battery 11, and a tip 160 of the protrusion 140 is positioned closer to the center of the underside of the assembled battery 11 than the installation location of the fixing part in the stacking direction of the assembled battery 11. This prevents short circuits caused by condensed water 300 dripping onto the non-insulated area below the fixing portion. The only difference between the end spacer 130 and the end spacer 1300 of the prior art is the presence or absence of the protrusion 140. Therefore, to manufacture the battery pack 11, it is sufficient to replace the end spacer 1300 of the battery pack of the prior art with the end spacer 130. In other words, the battery pack 11 can be easily manufactured while suppressing increases in manufacturing costs.

[0068] (12) One protrusion 140 is provided on each end in the width direction of the end spacer 130. This configuration allows the condensed water 300 to be efficiently guided from both ends in the width direction of the end spacer 130 to an insulating region on the bottom of the battery casing 12 that is closer to the center than the location of the partition 32.

[0069] (13) The sealant may be arranged on the insulating part in a line, a surface, or a dotted pattern on a substantially horizontal plane. In this case, dripping condensed water 300 can be effectively stopped on the insulating part. In particular, when the sealant is arranged on the insulating part in a line along a surface where condensation is likely to occur, the condensed water 300 can be more effectively stopped on the insulating part. On the other hand, when the sealant is arranged on the insulating part in a dotted or linear pattern, it becomes easier to arrange the sealant.

[0070] (14) The sealing material is water-repellent, so that dripping condensed water 300 can be effectively stopped on the insulating portion.

[0071] (15) The sealing material is a rubber or resin part fixed on the insulating part. By using a part that is easily elastically deformed as the sealing material, it becomes easier to make the sealing material adhere to other components that it comes into contact with.

[0072] (16) The surface of the second protrusion may be coated with resin, thereby preventing condensation from forming on the surface of the second protrusion.

[0073] (17) The lower end surface of the protrusion 140 is disposed in contact with the upper end surface of the partition 32. This arrangement ensures that the condensed water 300 is guided onto the insulating portion.

[0074] (18) The protrusion 140 has a generally L-shaped, generally U-shaped, generally circular, generally elliptical, generally polygonal, or generally polygonal cross section in the width direction of the battery pack 11. This configuration allows the condensed water 300 to be reliably guided toward the tip 160 even when the amount of condensed water 300 is large.

[0075] (19) A groove, a pipe, or a combination thereof may be formed integrally or separately in the region of the insulating portion that is located below the tip 160 of the protrusion 140. In this case, the condensed water 300 that drips from the tip 160 of the protrusion 140 can be prevented from accumulating on the insulating portion, and the condensed water 300 can be effectively drained.

[0076] (20) The insulating part is the container 13 that houses the battery pack 11. This allows the insulating part to be easily provided on the inner surface of the battery casing 12.

[0077] (21) The bottom of the protrusion 440 may be formed across the entire width of the end spacer 330. In this case, the protrusion 440 is disposed above the partition 32 across the entire width of the battery pack. As a result, the condensed water 300 can be more reliably guided to the insulating region of the bottom of the battery casing 12 that is closer to the center than the location where the partition 32 is disposed.

[0078] The present invention is not limited to the above-described embodiment, and can be implemented using any components without departing from the spirit of the present invention.

[0079] The above-described embodiments and modifications are merely examples, and the present invention is not limited to these details as long as the features of the invention are not impaired. Furthermore, although various embodiments and modifications have been described above, the present invention is not limited to these details. Other aspects that can be considered within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0080] 1: Battery pack 11,11a,11b:Battery assembly 12: Battery case 12a: Battery housing body 12b: Lid 13: Insulation case 21: Cooling duct insertion hole 22: Hole 31:Aperture 32: Partition 41: Cooling duct 110,110a,110b: Secondary battery 120, 120a, 120b: Spacer 130,330: End spacer 140,140a,140b,440:Protrusion 150: Meeting point 160: Tip 210, 210a, 210b: Side rails 220: End plate 230: Bolt 240:Superstructure 241a, 241b: Busbar cover 242: Busbar 243: Gas exhaust duct 300: Condensed water

Claims

1. A battery pack in which a battery pack is housed inside a metal battery case, Three coordinate axis directions in a three-dimensional orthogonal coordinate system are defined as a vertical direction, a stacking direction of the battery pack, and a width direction of the battery pack, respectively, The bottom of the battery casing is provided with: a first fixing portion disposed on an inner surface of the bottom portion in a region facing a lower surface of the battery pack, the first fixing portion fixing the battery pack upward; a partition portion that partitions the inner surface of the bottom portion into a plurality of regions; an insulating portion that insulates at least a central region of the bottom portion from among the plurality of partitioned regions; is provided, The battery pack comprises: a stack of alternately stacked secondary batteries and spacers, with secondary batteries at both ends; end spacers disposed on both ends of the laminate; Equipped with second fixing portions for fixing the battery pack downward are provided on a lower surface of the battery pack near both ends of the battery pack; the first fixing portion and the second fixing portion are provided coaxially opposite to each other, a bottom portion of the spacer extends in a stacking direction of the battery pack so as to cover a lower surface of one of the adjacent secondary batteries; The spacer and the end spacer have the following (1) or (2): (1) The bottoms of the end spacers extend in the stacking direction of the assembled batteries so as to cover the lower surfaces of the bottoms of the spacers, and the upper surfaces of the bottoms of the end spacers and the lower surfaces of the bottoms of the spacers face each other in the up-down direction, (2) The bottom of the end spacer extends in the stacking direction of the assembled battery so as to cover the lower surface of one of the adjacent secondary batteries, the bottom of the spacer extends in the stacking direction of the assembled battery so as to further cover the lower surface of the bottom of the end spacer, and the upper surface of the bottom of the spacer and the lower surface of the bottom of the end spacer face each other in the vertical direction, a protrusion portion is formed on a bottom portion of the end spacer, the protrusion portion protruding toward a center of the lower surface of the battery pack in a stacking direction of the battery pack; The tip of the protrusion is disposed closer to the center of the lower surface of the battery pack than the location of the partition in the stacking direction of the battery pack. Battery pack.

2. The battery pack according to claim 1 , wherein the partition portion is formed by disposing a sealant on the insulating portion.

3. The battery pack according to claim 1 , wherein the partition portion is made of the same material as the insulating portion and is integrally molded with the insulating portion.

4. 2. The battery pack according to claim 1, wherein the partition is provided by a step formed in a bottom of a battery casing, and the step is provided by forming the bottom of the battery casing so that a central portion thereof is lower than a position where the first fixing portion is disposed in a stacking direction of the battery pack.

5. 2. The battery pack according to claim 1, wherein a path for dripping condensed water is formed from a point where the upper surface of the bottom of the end spacer and the lower surface of the bottom of the spacer face each other to the tip of the protrusion.

6. The battery pack comprises: Side rails attached to both sides in the width direction; an end plate attached to the outside of the end spacer in the stacking direction; Furthermore, a second protrusion protruding in a stacking direction of the battery pack is formed integrally or separately on a bottom of at least one of the spacer, the side rail, the end plate, and the secondary battery; The battery pack according to claim 1 .

7. the second protrusion is formed on the bottom of one spacer, one main surface of the bottom of the spacer on which the second protrusion is formed and one main surface of the bottom of another spacer adjacent to the spacer with the secondary battery interposed therebetween form a facing portion where the surfaces face each other in the up-down direction, The second protrusion is disposed below the facing portion. The battery pack according to claim 6.

8. The battery pack according to claim 1 , wherein the protrusion has a vertical cross section in a stacking direction of the battery pack that is tapered such that the thickness in the vertical direction decreases toward the tip.

9. 2. The battery pack according to claim 1, wherein the protrusion comprises a substantially horizontal bottom portion extending in a stacking direction of the assembled battery, and a substantially vertical outer wall portion extending upward from one edge of the bottom portion.

10. The battery pack according to claim 1 , wherein a base end of the protrusion is disposed below a portion where an upper surface of the bottom portion of the end spacer and a lower surface of the bottom portion of the spacer face each other.

11. A battery pack to be incorporated into a battery pack, a stack of alternately stacked secondary batteries and spacers, with secondary batteries at both ends; end spacers disposed on both ends of the laminate; Equipped with Three coordinate axis directions in a three-dimensional orthogonal coordinate system are defined as a vertical direction, a stacking direction of the battery pack, and a width direction of the battery pack, respectively, fixing portions for fixing the battery pack downward are provided on a lower surface of the battery pack near both ends of the battery pack; a bottom portion of the spacer extends in a stacking direction of the battery pack so as to cover a lower surface of one of the adjacent secondary batteries; The spacer and the end spacer have the following (1) or (2): (1) The bottoms of the end spacers extend in the stacking direction of the assembled batteries so as to cover the lower surfaces of the bottoms of the spacers, and the upper surfaces of the bottoms of the end spacers and the lower surfaces of the bottoms of the spacers face each other in the up-down direction, (2) The bottom of the end spacer extends in the stacking direction of the assembled battery so as to cover the lower surface of one of the adjacent secondary batteries, the bottom of the spacer extends in the stacking direction of the assembled battery so as to further cover the lower surface of the bottom of the end spacer, and the upper surface of the bottom of the spacer and the lower surface of the bottom of the end spacer face each other in the vertical direction, a protrusion portion is formed on a bottom portion of the end spacer, the protrusion portion protruding toward a center of the lower surface of the battery pack in a stacking direction of the battery pack; The tip of the protrusion is disposed closer to the center of the lower surface of the battery pack than the location of the fixing portion in the stacking direction of the battery pack. The protrusion and the fixed portion are insulated from each other. Battery pack.

12. 12. The battery pack according to claim 11, wherein a path for dripping condensed water is formed from a point where the upper surface of the bottom portion of the end spacer and the lower surface of the bottom portion of the spacer face each other to the tip of the protrusion.

13. The battery pack comprises: Side rails attached to both sides in the width direction; an end plate attached to the outside of the end spacer in the stacking direction; Furthermore, a second protrusion protruding in a stacking direction of the battery pack is formed integrally or separately on a bottom of at least one of the spacer, the side rail, the end plate, and the secondary battery; The battery pack according to claim 11.

14. the second protrusion is formed on the bottom of one spacer, one main surface of the bottom of the spacer on which the second protrusion is formed and one main surface of the bottom of another spacer adjacent to the spacer with the secondary battery interposed therebetween form a facing portion where the surfaces face each other in the up-down direction, The second protrusion is disposed below the facing portion. The battery pack according to claim 13.

15. The battery pack according to claim 11 , wherein the protrusion has a vertical cross section in a stacking direction of the battery pack that is tapered such that the thickness in the up-down direction decreases toward the tip.

16. 12. The battery pack according to claim 11, wherein the protrusion comprises a substantially horizontal bottom portion extending in a stacking direction of the battery pack, and a substantially vertical outer wall portion extending upward from one edge of the bottom portion.

17. The battery pack according to claim 11 , wherein a base end of the protrusion is disposed below a portion where an upper surface of the bottom portion of the end spacer and a lower surface of the bottom portion of the spacer face each other.

18. The battery pack according to claim 1 , wherein the protrusions are provided on both ends of the end spacer in the width direction, one on each side.

19. The battery pack according to claim 11 , wherein the protrusions are provided on both ends of the end spacer in the width direction, one on each side.

Images