battery pack

Abstract

The purpose of the present invention is to manufacture a battery pack that has a plurality of battery blocks at a low cost.　An example of a specific configuration of the present invention is as described below. A battery pack comprising: a first battery block having a plurality of first batteries 1 and a plurality of first spacers 20 alternately stacked in a first direction; and a second battery block having a plurality of second batteries 1 and a plurality of second spacers 20 alternately stacked in the first direction, said first and second battery blocks being arranged in a direction that is perpendicular to a second direction, wherein the first spacers and the second spacers are formed integrally with a first coupling portion interposed therebetween, the first coupling portion 22, 23 being provided with inter-block side rails 70 that collectively press the first battery block and the second battery block in the first direction.

Description

[Technical Field]

[0001] The present invention relates to a battery pack having a plurality of battery blocks each having a plurality of batteries. [Background technology]

[0002] Traditionally, aqueous batteries such as lead-acid batteries, nickel-cadmium batteries, and nickel-metal hydride batteries have been the mainstream in the field of rechargeable secondary batteries. However, as electrical devices have become smaller and lighter, attention has been focused on lithium secondary batteries, which have high energy density, and their research, development, and commercialization have progressed rapidly.

[0003] Meanwhile, in response to issues such as global warming and depleting fuels, automobile manufacturers are developing electric vehicles (EVs) and hybrid electric vehicles (HEVs), which use electric motors to partially assist their drive, and high-capacity, high-output secondary batteries are becoming increasingly popular as their power sources. High-voltage non-aqueous lithium secondary batteries have attracted attention as a power source that meets these requirements. Prismatic lithium secondary batteries, in particular, have excellent volumetric efficiency when packed, so there is growing expectation for the development of prismatic lithium secondary batteries for HEVs and EVs.

[0004] When multiple secondary batteries are modularized, each battery cell must be held in place by sandwiching it between insulating spacers made of resin, etc. Therefore, for a given number of battery cells, N, N+1 insulating spacers are always required, and the assembly method requires that the battery cells and insulating spacers be stacked alternately one by one.

[0005] The multiple batteries are fastened in the stacking direction, but the positions of the individual batteries shift before and after fastening. Patent Document 1 describes a battery arrangement configuration that prevents stress from being generated in each battery even if the positions of the batteries shift when, for example, two battery blocks are fastened with a common fastening plate. In Patent Document 1, even when the multiple battery blocks share a common fastening plate, the spacers between the batteries are separate components in each battery block. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2019-149227 Summary of the Invention [Problem to be solved by the invention]

[0007] In this invention, a combination of batteries and spacers is called a battery block, and a combination of battery blocks is called a battery pack. A battery block is assembled by stacking battery cells and insulating spacers one by one, alternating between them. In prior art, including Patent Document 1, the assembly is performed by stacking battery cells and insulating spacers one by one, so the more battery cells there are, the greater the number of labor hours and parts required. This increases manufacturing costs.

[0008] Furthermore, if a single battery block does not provide sufficient output voltage, it is necessary to connect multiple battery blocks together to form a battery pack. In such cases, with conventional technology, the battery user, such as an automobile manufacturer, is required to connect the purchased battery blocks in-house.

[0009] Therefore, the process of assembling multiple batteries with spacers in between to form a battery block, and the process of arranging multiple such battery blocks to form a battery assembly, have been a significant burden on manufacturing costs for both battery manufacturers and battery users.The object of the present invention is to realize a configuration that shortens and simplifies the process of forming such a battery assembly as a whole, thereby reducing the manufacturing costs of the battery assembly.

[0010] In other words, the present invention aims to provide a secondary battery module that uses two or more blocks of battery cells, and that can suppress an increase in the number of accompanying insulating spacer parts and the labor required to assemble them, even if the number of battery cells used increases. [Means for solving the problem]

[0011] The present invention solves the problems described above and is primarily configured as follows. Specifically, rather than assembling battery blocks individually, multiple battery blocks are assembled simultaneously. Specifically, the spacers, end plates, and side plates used for fastening the batteries, which are placed between the batteries, are common to each block that makes up the assembled battery. Furthermore, by assembling multiple blocks simultaneously, rather than assembling the assembled battery block by block, the labor required is reduced. Specific means of the present invention are as follows.

[0012] (1) An assembled battery comprising a first battery block having a configuration in which a plurality of first batteries and a plurality of first spacers are alternately stacked in a first direction, and a second battery block having a configuration in which a plurality of second batteries and a plurality of second spacers are alternately stacked in the first direction, arranged in a direction perpendicular to the second direction, wherein the first spacers and the second spacers are integrally formed via a first connecting portion, and an inter-block side rail is arranged in the first connecting portion to press the first battery block and the second battery block together in the first direction.

[0013] (2) The battery pack described in (1) is characterized in that first end plates are arranged at both ends of the first battery block in the first direction, second end plates are arranged at both ends of the second battery block in the first direction, and the inter-block side rails press the first battery block in the first direction via the first end plates and press the second battery block in the first direction via the second end plates.

[0014] (3) The battery pack described in (2) is characterized in that the first end plate and the second end plate are formed continuously via a second connecting portion, and the inter-block side rail is arranged at the second connecting portion. [Effects of the Invention]

[0015] According to the present invention, multiple battery blocks are assembled simultaneously, which significantly reduces the cost of the assembly process. Furthermore, according to the present invention, the insulating plates that hold the battery cells are connected between blocks rather than for each block, which reduces the number of parts. Furthermore, because battery users purchase multiple battery blocks already connected, they can reduce the labor required to connect the battery blocks. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. [Figure 2] FIG. 2 is an exploded perspective view of the battery block. [Figure 3] FIG. 10 is a plan view of a battery pack in which four battery blocks are arranged in a comparative example. [Figure 4] 1 is a plan view of a battery pack in which four battery blocks are arranged in Example 1 of the present invention. [Figure 5] 1 is an exploded perspective view of a battery pack in which four battery blocks are arranged in accordance with a first embodiment of the present invention. [Figure 6] FIG. 2 is a perspective view of a spacer according to the first embodiment. [Figure 7] FIG. 2 is a perspective view of an inter-block side rail according to the first embodiment. [Figure 8] FIG. 10 is a perspective view showing another example of a spacer. [Figure 9] FIG. 10 is a perspective view showing still another example of a spacer. [Figure 10] FIG. 10 is a perspective view of a battery pack according to a second embodiment. [Figure 11] FIG. 10 is an exploded perspective view of a battery pack according to a second embodiment. [Figure 12] FIG. 10 is a perspective view of a battery pack according to a third embodiment. [Figure 13] FIG. 10 is an exploded perspective view of the battery pack of the third embodiment. [Figure 14] FIG. 10 is a perspective view of a battery pack according to a fourth embodiment. [Figure 15] FIG. 10 is an exploded perspective view of the battery pack of Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below with reference to examples. [Example]

[0018] The present invention is characterized by a configuration that allows multiple battery blocks to be formed simultaneously, but first, as a comparative example, a conventional assembly configuration for a single block will be described.

[0019] FIG. 1 is a perspective view of a battery cell 1. As shown in FIG. 1, the battery cell 1 has a battery can 2, a battery lid 3, a positive electrode terminal 4, a negative electrode terminal 5, a gas release valve 6, an electrolyte, charge / discharge elements, and an insulating case (not shown). The battery cell 1 uses a rechargeable secondary battery such as a lithium-ion secondary battery. The battery cell 1 of the first embodiment corresponds to a single cell of a battery pack according to one embodiment of the present invention.

[0020] The battery can 2 has a rectangular parallelepiped shape with one end open, and is made of aluminum or an aluminum alloy. The battery can 2 has a pair of opposing side plates 2a with a large area, a pair of opposing side plates 2b with a small area, and a bottom plate 2c on the opposite side of the opening. The internal space of the battery can 2 contains charging / discharging elements covered with an insulating case, and an electrolyte is poured into it. The positive electrode of the charging / discharging elements is connected to a positive terminal 4, and the negative electrode of the charging / discharging elements is connected to a negative terminal 5.

[0021] The battery lid 3 has the same rectangular flat plate shape as the bottom plate 2c, is made of aluminum or an aluminum alloy, and closes the opening of the battery can 2. The battery lid 3 is joined to the opening of the battery can 2 by joining means such as laser welding. A gas release valve 6 is provided in the center of the battery lid 3. When the battery cell 1 generates heat due to an abnormality such as overcharging, generating gas, and the pressure inside the battery can 2 increases and reaches a predetermined pressure, the gas release valve 6 opens, releasing the gas from inside the container and reducing the pressure inside the battery can 2.

[0022] Furthermore, through-holes (not shown) are formed at one end and the other end of the battery lid 3, and a positive terminal 4 and a negative terminal 5 are attached to the through-holes. The portions of the positive terminal 4 and the negative terminal 5 that are exposed to the outside from the battery lid 3 are each formed as a rectangular parallelepiped with a flat top surface. Electric power generated in the battery cell 1 is supplied to an external device via the positive terminal 4 and the negative terminal 5, or externally generated electric power is supplied to a charging / discharging element via the positive terminal 4 and the negative terminal 5 for charging.

[0023] Fig. 2 is an exploded perspective view of a battery block. As shown in Fig. 2, the battery block includes a plurality of stacked battery cells 1 and spacers 20, a pair of end spaces 30, a pair of end plates 40, and a pair of side rails 50.

[0024] The spacers 20 are made of insulating synthetic resin and, as shown in Figure 2, are sandwiched alternately between adjacent battery cells 1 and stacked together with the battery cells 1 in the x direction. Each spacer 20 has a protrusion 21 extending in the x direction at its end, and holds the battery cell 1 in a recess formed by the protrusion 21, thereby restricting the y and Z directions. Note that in this specification, when the x direction is defined as the first direction, the second direction perpendicular to the x direction is sometimes referred to as the y direction.

[0025] The end spacer 30 has basically the same structure as the spacer 20. Specifically, it is made of insulating synthetic resin, with the outermost battery cell 1 positioned on the outside. Since the battery cells 1 are positioned on only one side of the end spacer 30, the protrusions 31 are formed on only one side of the end spacer 30.

[0026] End plates 40 are placed on the outside of the end spacers 30. Side rails 50 press the end plates 40 on both sides in the x direction, securing the stack of battery cells 1 and spacers 20 in place. The end plates may be made of metal or resin. In either case, they must have the mechanical strength to stably fasten the stack of battery cells 1 and spacers 20 together.

[0027] 2, holes 51 in side rails 50 are aligned with holes 41 in the end plates, and the stack of battery cells 1 and spacers 20 is tightened and fixed in the x direction using screws 60. Side rails 50 are typically made of metal.

[0028] In Figure 2, bus bar covers 200 made of an insulating material such as resin are arranged to correspond to the terminals 4 and 5 formed on the battery cells 1. The battery cells 1 are arranged so that the terminals of adjacent batteries are either positive or negative. The positive and negative electrodes 4 and 5 of adjacent batteries are connected by bus bars 210. End bus bars 220 are connected to the outermost terminals of each block, which are then connected to other battery blocks or external circuits.

[0029] Battery blocks are often used with multiple battery cells 1 connected in series, but there are cases where a sufficient output voltage cannot be obtained even with a series connection. In such cases, multiple battery blocks are connected in series. If a larger output current is desired, the battery blocks are connected in parallel. This is a matter of terminal connection, and the present invention can be applied to either case.

[0030] The top diagram in Figure 3 is a plan view showing four battery blocks arranged side by side and connected in series. In Figure 3, each battery block is assembled separately. In Figure 3, battery cells 1 and spacers 20 are stacked alternately. Note that in Figure 3, the protrusions formed on the ends of the spacers 20 have been omitted to avoid complicating the illustration. The stack of battery cells 1 and spacers 20 is sandwiched between end spacers 30 and end plates 40, and is pressed and fixed by side rails 50.

[0031] In the battery cell 1 in Figure 3, the positive electrode terminal 4, negative electrode terminal 5, gas release valve 6, electrolyte injection hole and plug 7, etc. are omitted. Adjacent batteries 1 are stacked so that the positive electrode terminals and negative electrode terminals of adjacent batteries 1 are adjacent and facing in opposite directions. In Figure 3, adjacent positive electrode terminals and negative electrode terminals are connected by bus bars 210. End bus bars 220 are connected to the terminals at the ends of each block. The end bus bars 220 are connected to the electrode terminals of the adjacent battery block or to the terminals of an external device.

[0032] The lower diagram in Figure 3 is a front view of each battery block. In Figure 3, the flanges of the side rails 50 are stacked on the end plates 40, and the holes in the flanges are aligned with the holes in the end plates. The stack of battery cells 1 and spacers 20 is then clamped and pressed together with screws 60 to secure the battery blocks in place.

[0033] In the configuration shown in Figure 3, the four battery blocks are manufactured independently by the battery manufacturer. Therefore, the manufacturing cost is four times the manufacturing cost of a single battery block. Furthermore, the four battery blocks must be connected by the user, which places a corresponding burden on the user.

[0034] FIG. 4 shows a plan view and a front view of a battery pack according to a first embodiment of the present invention. In FIG. 4 as well, the protrusions of the spacers 20 have been omitted to avoid complicating the illustration. A feature of FIG. 4 is that four battery blocks are formed simultaneously as a single unit. In FIG. 4, the spacers 20 arranged between the battery cells 1 are formed as a single unit, with four battery cells 1 arranged between the spacers. The end spacers 30 and end plates 40 that sandwich the battery cells 1 and spacers 20 from both sides are also formed as a single unit, with four battery cells 1 arranged between the spacers.

[0035] In Figure 4, notches are formed in the spacer 20, end spacer 30, and end plate 40, and extensions 71 of inter-block side rails 70 pass through these notches. The flanges 72 of the inter-block side rails 70 press against the end plates 40 with screws 80 on the outside of the end plates 40, thereby pressing and securing the battery blocks from both sides. Note that although pressing is expressed as tightening in Figures 4 and 5, the concept of pressing is broader than tightening. For example, instead of using screws, pressing may be achieved by using swaging or the like.

[0036] The same structure is formed at the boundary between each battery block, i.e., in three locations. The outside of the outer battery block is fastened by a side rail 50, as in Figure 3. The battery cells 1 are also arranged in the same manner as in Figure 3. Therefore, the arrangement of the bus bars 210 and end bus bars 220 is basically the same as in Figure 3. In Figure 4, the battery pack is made up of four battery blocks, but the only terminals that connect to the outside are the two end bus bars 220 arranged on the battery blocks at both ends.

[0037] The lower diagram in Fig. 4 is a front view of the battery pack according to Example 1. In the front view of Fig. 4, end plates 40 are formed integrally with each other for four battery blocks. Notches 42 are formed in end plates 40 at the boundaries between the battery blocks, and extensions 71 of inter-block side rails 70 are positioned in these notches 42. Flanges 72 of inter-block side rails 70 contact the outer surfaces of end plates 40 and are pressed by screws 80. When screws 80 are pressed, the two battery blocks are pressed and fastened together by end plates 40 and inter-block side rails 70.

[0038] In the front view of Figure 4, the portion of end plate 40 where notch 42 is formed has a narrower width. This portion is referred to as connection portion 43. Connection portion 43 can also be called link portion 43. Connection portion 43 has a smaller bending strength or section modulus than other portions of end plate 40. Therefore, even if dimensional errors occur between battery blocks, stress is relieved at connection portion 43.

[0039] FIG. 5 is an exploded perspective view of Example 1. In FIG. 5, four battery blocks are integrally formed. As shown in FIG. 5, battery cells 1 and spacers 20 are stacked alternately in the x direction (sometimes referred to as the first direction). In FIG. 5, the spacers 20 are shown as a single sheet because they are thinner than the battery cells 1. To avoid complicating the illustration, the protrusions 21 formed on the spacers 20 are omitted.

[0040] In Figure 5, spacer 20 is formed in common for four battery blocks. Notches 22 are formed in spacer 20 at the boundaries between each block, and extensions 71 of inter-block side rails 70 are inserted through these notches 22. Connections 23 where notches 22 are formed in spacer 20 have lower bending strength or section modulus than other parts, so even if dimensional errors occur between the battery blocks, these connections can absorb stress.

[0041] This feature is also true for the end spacers 30. The end spacers 30 are formed in common for the four battery blocks, with notches 32 formed at their boundaries. The width of the end spacers 30 where the notches 32 are formed is narrower, making the bending strength or section modulus smaller than other parts. Therefore, even if dimensional errors occur between the battery blocks, the connection parts 33 can absorb stress.

[0042] The configuration of the end plates 40 is as explained in Figure 4. The end plates 40 are basically the same as the spacers 20 and end spacers 30. The extensions 71 of the inter-block side rails 70 shown in Figure 5 are inserted through the notches 22 of the spacers 20, the notches 32 of the end spacers 30, and the notches 42 of the end plates 40, and the flanges 72 of the inter-block side rails 70 press the two end plates 40 together in the stacking direction (x direction), fixing the stacked structure of the battery cells 1 and spacers.

[0043] In Figure 5, the outside of the battery blocks on both sides in the y direction (sometimes referred to as the direction perpendicular to the first direction) are pressed against two end plates 40 by side rails 50, just as in the past, and the battery cells 1 and spacers 20 are fixed in place in the stacking direction. In Figure 5, the spacers 20, end spacers 30, and end plates 40 are the size of four battery cells 1, but because these materials are formed by molding resin, mass production is easy once the mold is designed, so the increased size does not result in a significant increase in costs. In fact, the reduced number of parts has the effect of reducing costs.

[0044] End plates 40 are often made of metal, in which case they are press-molded or die-cast. In the case of press molding, mass production is easy once the press mold is manufactured once. Therefore, even when the end plates are made of metal, the cost savings from reducing the number of parts outweigh the cost increase from larger parts.

[0045] Figure 6 is a perspective view of a spacer 20 used in the present invention. The spacer 20 in Figure 6 is a spacer that corresponds to four battery blocks. The protrusions on the spacer 20 have been omitted from Figure 6. In Figure 6, a notch 22 is formed in the spacer 20 in a portion that corresponds to the boundary between the battery blocks. An extension 71 of an inter-block side rail 70 is inserted into this notch 22, pressing and fixing the stack of battery cells 1 and spacers 20.

[0046] In Figure 6, the width of spacer 20 is narrower where notch 22 is formed, and this portion is referred to herein as connection portion 23. In other words, connection portion 23 is a mechanically weak portion, and even if slight dimensional errors occur between battery blocks due to manufacturing errors, connection portion 23 will deform and relieve stress. In other words, connection portion 23 can be used as a mechanical buffer.

[0047] The connection portion 23 can be configured to be actively used as a buffer. One configuration is to make the spacer plate thickness at the connection portion 23 thinner than other portions in order to further reduce the mechanical strength of the connection portion 23. In other words, it is sufficient for the connection portion 23 to allow the spacer 20 to exist as a single unit when the battery cell 1 is assembled into the block, so the reliability of the mechanical strength of the connection portion 23 of the spacer 20 does not become an issue.

[0048] Another way to use the connection portion 23 of the spacer 20 as a buffer is to form only the connection portion of the spacer 20 from an elastic material such as rubber or polypropylene. The portion that functions as the spacer 20 is then formed from an insulating resin. This type of configuration can be formed, for example, using a technique known as two-tone molding. This configuration also applies to the end spacer 30 and the end plate 40.

[0049] Figure 7 is a perspective view of an inter-block side rail 70 that passes through the cutouts 22 of spacers 20, etc. In Figure 7, the extensions 71 of the inter-block side rail 70 pass through the cutouts of spacers 22, etc. The flanges 72 come into contact with the end plates 40, and screws 80 are inserted into threaded holes 73 formed in the flanges 72 and threaded holes formed in the end plates 40, applying pressure to tighten the battery cells 1 and spacers 20 together, thereby fastening the stack of battery cells 1 and spacers 20 together.

[0050] The inter-block side rail 70 can be formed by various methods. Figure 7 shows an example in which a single metal plate is formed by sheet metal processing. That is, a shape corresponding to the developed plane of the inter-block side rail 70 is created, for example, by pressing. Then, the shape shown in Figure 7 can be processed by bending the metal using sheet metal. Although the shape is different, the manufacturing process is basically the same as that of the side rail 50.

[0051] The inter-block side rail 70 shown in Figure 7 is an example, and many other variations exist. It is not necessary to insist on sheet metal processing; the extension portion 71 and flange portion 72 of the inter-block side rail 70 can be manufactured separately and then fastened by welding, screws, crimping, or other means. Furthermore, the extension portion 71 can be directly attached to the end plate 40 by welding, screws, crimping, or other means.

[0052] FIG. 6 shows an example in which the notch 22 is formed on the upper side of the spacer 20. However, depending on the layout requirements, the notch 22 may be formed on the lower side of the spacer 20, as shown in FIG. 8. In this case, the connecting portion 23 is disposed on the upper side of the spacer, but the operation is basically the same as that described for FIG. 6. Also, the configuration of FIG. 8 can use a configuration similar to the inter-block side rail 70 of FIG. 7.

[0053] Figure 9 shows an example in which holes 25, rather than notches, are formed in the spacer 20 in the areas corresponding to the boundaries of the battery blocks. In this case, the inter-block side rails are inserted through these holes 25. Therefore, the same inter-block side rails as in Figure 7 cannot be used. For example, an extension 71 of a rod-shaped inter-block side rail 70 with a cross section similar to the hole 25 in the spacer 20 is inserted, and a flange 72 is attached to the extension 71 of the inter-block side rail 70 on the outside of the end plate 40 by means of screws, crimping, welding, or other means. This flange 72 is then used to press the stack of battery cells 1 and spacers 20 in the stacking direction.

[0054] In this embodiment, an example in which four battery blocks are used is described, but the number is not limited to this and the battery can be configured using at least two battery blocks.

[0055] In this embodiment, connection portion 43 has been used as an example of a fastening portion of the present invention. In this embodiment, the end plates, spacers, and end spacers have a notched structure. Forming them as a single unit reduces the number of parts, which is preferable. However, this portion can also be configured to connect multiple end plates, spacers, and end spacers with connecting members. Because parts corresponding to each battery block can be manufactured individually, this can easily be applied to battery packs with a different number of battery blocks. [Example]

[0056] FIG. 10 is a perspective view of a battery pack according to Example 2. The configuration of FIG. 10 differs from that of Example 1 in that the end plate and side rail are integrated into one component 100. In FIG. 10, two battery blocks are arranged side by side, rather than four. However, in FIG. 10, the spacers and end spacers are integrated for two battery blocks, just as in Example 1. In FIG. 10, the battery cells 1 and spacers 20 are stacked alternately in the stacking direction, but the spacers 20 are not visible. Instead, protrusions 21 that are part of the spacers 20 are visible at the ends of the blocks.

[0057] 10 shows two battery blocks, but as shown in FIG. 5 of Example 1, the spacers are integrated and battery cells are assembled for the two battery blocks simultaneously. Each of the two battery blocks is sandwiched between two end spacers 30.

[0058] 10 differs from Example 1 in that the end plate and the side rail are integrated into an integrated part 100. However, like Example 1, the integrated part 100 is also pressed and fastened in the stacking direction by the inter-block side rail 70. The two integrated parts 100 are connected by screws 101.

[0059] Figure 11 is an exploded perspective view of Figure 10. In Figure 11, the two end plates and two side rails are replaced by two U-shaped, plate-like integrated components 100. The integrated components 100 have a simple shape, being simply formed by bending a plate-like component. Therefore, they can be manufactured inexpensively. The two integrated components 100 are connected by screws 101.

[0060] 11, the stacked structure of battery cells 1 and spacers 20 is pressed in the stacking direction by inter-block side rails 70, just like in Example 1. That is, the inter-block side rails are inserted through the cutouts in the spacers 20, end spacers 30, and integrated component 100, and press and secure the stacked structure from the outside of the integrated component 100. [Example]

[0061] Fig. 12 is a perspective view of the battery pack of Example 3, and Fig. 13 is an exploded perspective view of the battery pack of Example 3. In Figs. 12 and 13 as well, the end plate and side rail form an integrated part 110. The configurations of Figs. 12 and 13 differ from Fig. 10 of Example 2 in the shape of the integrated part 110. In Figs. 12 and 13, the two integrated parts 110 are connected by screws 80 on the flanges of the inter-block side rails 70.

[0062] That is, the screws 80 press the battery cells 1 and spacers 20 in the stacking direction, while at the same time fixing the integrated component 110. Compared to the structure of Example 2, the structure of Example 3 makes it possible to omit the screw fastening step using the screws 101 shown in Figure 11. The other configurations of Example 3 are the same as those described in Example 2. [Example]

[0063] FIG. 14 is a perspective view of a battery pack according to Example 4. In FIG. 14, the end plates and side rails are also integrated into one piece. However, while the end plates and side rails in Examples 2 and 3 are configured as two integrated pieces, Example 4 consists of only one piece. That is, in Example 4, the integrated part 120 of the end plates and side rails is a rectangular plate-shaped frame into which the stack of battery cells 1 and spacers 20 is inserted. The stack of battery cells 1 and spacers 20 is pressed and fastened by the inter-block side rails 70, just like Examples 2 and 3.

[0064] Fig. 15 is an exploded perspective view of Example 4. As shown in Fig. 15, an integrated part 120 of an end plate and a side rail is a plate-like rectangular frame body. However, in the integrated part 120, notches 122 are formed in portions corresponding to the notches of the spacer 20 and the end spacer 30.

[0065] The inter-block side rails 70 are inserted through these cutouts 122, and screws 80 are used to press against the stack of battery cells 1 and spacers 20, fastening the battery block together. The rest of the configuration of Example 4 is the same as that described for Examples 2 and 3. In Example 4, the end plates and side rails are formed from a single integrated part 120, further reducing manufacturing costs. [Explanation of symbols]

[0066] DESCRIPTION OF SYMBOLS 1...battery, 2...battery can, 3...battery lid, 4...positive terminal, 5...negative terminal, 6...gas release valve, 20...spacer, 21...spacer end projection, 22...spacer notch, 23...spacer connection portion, 30...end spacer, 31...end spacer end projection, 32...end spacer notch, 33...end spacer connection portion, 40...end plate, 42...end plate notch, 43...end plate connection portion, 50...side rail, 60...screw, 70...inter-block side rail, 71...extension portion, 72...flange portion, 73...hole, 80...screw, 100...integrated part of end plate and side rail of Example 2, 101...screw, 102...notch, 110...integrated part of end plate and side rail of Example 3, 101...screw, 102...Notch, 120...Integrated part of end plate and side rail of Example 4, 122...Notch, 200...Busbar case, 210...Busbar, 220...End busbar

Claims

1. a first battery block having a configuration in which a plurality of first batteries and a plurality of first spacers are alternately stacked in a first direction; a second battery block having a configuration in which a plurality of second batteries and a plurality of second spacers are alternately stacked in the first direction, the second battery block being arranged in a direction perpendicular to the first direction; the first spacer and the second spacer are integrally formed via a first connecting portion, and a first notch cut along the first direction is formed in the first connecting portion; the first cutout is located at a boundary between the first battery block and the second battery block, and an inter-block side rail is disposed at the boundary and the first cutout, the inter-block side rail having a pressing portion formed therein that commonly presses the first battery block and the second battery block in the first direction.

2. first end plates are disposed at both ends of the first battery block in the first direction; second end plates are disposed on both ends of the second battery block in the first direction; 2. The battery pack according to claim 1, wherein the pressing portion of the inter-block side rail presses the first battery block in the first direction via the first end plate, and presses the second battery block in the first direction via the second end plate.

3. the first end plate and the second end plate are formed continuously via a second connecting portion, 3. The battery pack according to claim 2, wherein the inter-block side rail is disposed in the second connecting portion.

4. the inter-block side rail has an extension portion extending in the first direction and a flange portion extending in a direction perpendicular to the first direction, The battery pack according to claim 1 , wherein the extension portion passes through the boundary portion and the first cutout.

5. The inter-block side rail has an extension portion extending in the first direction; a first flange portion extending at a first end of the extension portion in a direction perpendicular to the first direction; a second flange portion extending in a direction perpendicular to the first direction at a second end portion of the extension portion opposite to the first end portion; the first flange portion presses the first battery block via the first end plate; 3. The battery pack according to claim 2, wherein the second flange portion presses the second battery block via the second end plate.

6. The inter-block side rail has an extension portion extending in the first direction; a first flange portion extending at a first end of the extension portion in a direction perpendicular to the first direction; a second flange portion extending in a direction perpendicular to the first direction at a second end portion of the extension portion opposite to the first end portion; the extension portion is inserted through the boundary portion and the first cutout, the first flange portion presses the first battery block via the first end plate; 4. The battery pack according to claim 3, wherein the second flange portion presses against the second battery block via the second end plate.

7. A battery pack described in any one of claims 4 to 6, characterized in that the first cutout is formed in a rectangular shape, and the extension portion of the inter-block side rail passes through the boundary portion and the first cutout.

8. a second notch cut along the first direction is formed in the second connecting portion; 4. The battery pack according to claim 3, wherein an extension of the inter-block side rail extending in the first direction is inserted through the second notch.

9. 7. The battery pack according to claim 1, wherein the inter-block side rails are formed by bending a single metal plate.

10. 5. The battery pack according to claim 4, wherein the flange portion and the extension portion are connected by welding, crimping, or screwing.

11. 7. The battery pack according to claim 1, wherein the first connecting portion has a bending strength smaller than that of the first spacer.

12. 9. The battery pack according to claim 8, wherein the second connecting portion has a bending strength smaller than that of the second end plate.

13. 7. The battery pack according to claim 1, wherein the first spacer and the second spacer are made of resin.

14. 7. The battery pack according to claim 2, wherein the first end plate and the second end plate are made of metal or resin.

15. A battery pack described in any one of claims 1 to 6, characterized in that there are only two terminals connected to the outside from the battery pack.

Images