JP7787649B2 - Battery pack, battery pack manufacturing method, and battery pack manufacturing device - Google Patents

Description

This disclosure relates to a battery pack, a battery pack manufacturing method, and a battery pack manufacturing apparatus.

To obtain the desired output voltage, a battery pack made up of multiple lead-acid batteries is sometimes used. Patent Document 1 below discloses a battery pack in which multiple lead-acid batteries are housed in a storage case and connected in series. The lead-acid batteries included in this battery pack have a battery capacity of 300 Ah or less per battery, with multiple identical-polarity terminals.

JP 2011-146222 A

As in Patent Document 1, when a storage battery is housed in a conductive housing such as a metal frame, a short circuit may occur between the housing and the storage battery. This can significantly reduce the performance of the battery pack.

One aspect of the present disclosure aims to provide a battery pack, a method for manufacturing a battery pack, and an apparatus for manufacturing a battery pack that can prevent short circuits between the housing and the storage battery.

A battery pack according to one aspect of the present disclosure includes a conductive housing, a battery group having multiple storage batteries housed in the housing, and an insulating side spacer disposed between the inner surface of the housing and the battery group in a plan view.

In a battery pack according to one aspect of the present disclosure, in plan view, insulating side spacers are disposed between the inner surface of the conductive housing and the battery group. This makes it possible to prevent short circuits between the inner surface of the housing and the storage batteries included in the battery group.

The thickness of the side spacers may be 1 mm or more in plan view. In this case, it is possible to effectively prevent short circuits between the inner surface of the housing and the storage batteries included in the battery pack.

In plan view, the side spacers may contact the inner surface of the housing and surround the battery group. In this case, it is possible to effectively prevent short circuits between the inner surface of the housing and the storage batteries included in the battery group.

The battery pack may have fastening portions that fasten the side spacers to the inner surface. In this case, the fastening portions secure the side spacers to the housing, preventing the side spacers from protruding from between the housing and the battery group. This makes it possible to more effectively prevent short circuits between the inner surface of the housing and the storage batteries included in the battery group.

The side spacer may have multiple insulating members stacked on top of each other in the direction in which the inner surface and the battery group face each other. In this case, the side spacer can be formed by inserting, for example, a number of insulating members corresponding to the size of the gap between the inner surface and the battery group. This makes it possible to manufacture a wide variety of battery packs even when the type of housing is limited.

The side spacer may have a fixing portion that fixes multiple insulating members together. In this case, the edge member will not protrude from between the housing and the battery group, allowing the side spacer to maintain its proper function.

The housing has a bottom, a frame that stands along the edge of the bottom, and additional spacers that are fixed to the bottom and frame within the frame, and the side spacers may be in contact with the additional spacers. In this case, the internal space of the housing can be narrowed while suppressing cost increases compared to when a large number of side spacers are used. In addition, even when the housing has additional spacers, it is possible to prevent short circuits between the housing and the battery group.

A method for manufacturing a battery pack according to another aspect of the present disclosure includes a first step of accommodating insulating side spacers in a conductive housing, and a second step of accommodating multiple storage batteries in the housing. The multiple storage batteries include multiple first storage batteries and multiple second storage batteries. In the first step, a first enclosure is formed that is composed of side spacers arranged along the inner surface of the housing and that contacts the inner surface. In the second step, a second enclosure is formed that includes multiple first storage batteries arranged along the inner surface of the first enclosure and that contacts the first enclosure, and at least some of the multiple second storage batteries are arranged inside the second enclosure.

In a method for manufacturing a battery pack according to another aspect of the present disclosure, a first enclosure composed of insulating side spacers is first formed. Next, a second enclosure is formed that contains a plurality of first storage batteries arranged along the inner surface of the first enclosure and that contacts the first enclosure. At least some of the second storage batteries are then arranged inside the second enclosure. This prevents the side spacers from being crushed by the storage batteries in the direction of insertion, for example, when the storage batteries are placed in the housing. This ensures that the battery group is well surrounded by the side spacers in a plan view, preventing short circuits between the inner surface of the housing and the storage batteries included in the battery group.

In the first step, the side spacers may be fixed to the inner surface of the housing. In this case, it is possible to effectively prevent the side spacers from shifting position before the second enclosure is formed.

In the first step, a third storage battery included in the second enclosure or disposed inside the second enclosure may be housed in the housing. Alternatively, in the first step, multiple third storage batteries may be housed in the housing, and in the second step, at least some of the multiple third storage batteries may be housed in the second enclosure. In these cases, for example, by housing the third storage battery before housing the side spacers, the side spacers can be sandwiched between the third storage battery and the housing. This prevents the side spacers from shifting position during the manufacture of the battery pack.

In a second step, some of the second storage batteries may be housed in a housing before the second enclosure is formed.

According to yet another aspect of the present disclosure, a battery pack manufacturing apparatus includes a side spacer arrangement unit that arranges insulating side spacers in a conductive housing, and a battery arrangement unit that arranges multiple storage batteries in the housing. The multiple storage batteries include multiple first storage batteries and multiple second storage batteries. The side spacer arrangement unit arranges the side spacers along the inner surface of the housing to form a first enclosure made up of the side spacers and in contact with the inner surface. The battery arrangement unit arranges the multiple first storage batteries along the inner surface of the first enclosure to form a second enclosure containing the multiple first storage batteries and in contact with the first enclosure, and arranges at least a portion of the multiple second storage batteries inside the second enclosure.

In a battery pack manufacturing apparatus according to yet another aspect of the present disclosure, the side spacer arrangement unit arranges side spacers along the inner surface of the housing to form a first enclosure made up of the side spacers and in contact with the inner surface. The battery arrangement unit arranges the first batteries along the inner surface of the first enclosure to form a second enclosure containing the first batteries and in contact with the first enclosure, and arranges at least some of the second batteries inside the second enclosure. This allows the housing to accommodate the batteries without the batteries crushing the side spacers. This makes it possible to prevent short-circuiting between the inner surface of the housing and the batteries included in the battery group.

One aspect of the present disclosure provides a battery pack, a method for manufacturing a battery pack, and an apparatus for manufacturing a battery pack that can prevent short circuits between the housing and the storage battery.

FIG. 1 is a schematic plan view showing a battery pack according to an embodiment. FIG. 2 is a perspective view showing a part of the storage battery according to the embodiment in a cutaway state. FIG. 3( a ) is a view showing the positive electrode as viewed from a first direction, and FIG. 3( b ) is an enlarged cross-sectional view taken along line IIIb-IIIb in FIG. 3( a ). FIG. 4 is a plan view showing the negative electrode according to the embodiment. FIG. 5 is a schematic diagram of a manufacturing apparatus for manufacturing the battery pack according to the embodiment. 6A to 6C are diagrams for explaining a method for manufacturing a battery pack according to an embodiment. FIG. 7A is a schematic plan view showing a housing according to a modified example, and FIG. 7B is a schematic cross-sectional view showing the main parts of a housing and a side spacer according to another modified example. FIG. 8(a) is a schematic plan view showing a battery pack according to yet another modified example, and FIG. 8(b) is an end view taken along line VIIIb-VIIIb in FIG. 8(a).

A preferred embodiment of one aspect of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that in the following description, identical elements or elements with identical functions will be designated by the same reference numerals, and duplicate explanations will be omitted.

Figure 1 is a schematic plan view showing a battery pack according to this embodiment. The battery pack 100 shown in Figure 1 is a battery pack containing multiple cells of the same type, and is used, for example, as an automobile battery, a backup power source used during power outages, or the main power source for electric vehicles (or electric vehicles) such as electric forklifts. The battery pack 100 has a housing 101, a battery group 102, and multiple side spacers 103.

The housing 101 is a conductive member that houses the battery pack 102 and side spacers 103. In this embodiment, the battery pack 102 and side spacers 103 are tightly packed into the housing 101. This effectively prevents damage to the battery pack 102 due to vibrations that occur during movement of the electric vehicle, for example, when the battery pack is mounted on an electric vehicle. As shown in FIG. 6(a) described below, the housing 101 has a bottom 111 and a frame 112 that extends along the edge of the bottom 111. The bottom 111 and the frame 112 are each formed, for example, from a metal plate or an alloy plate and are integrated with each other. The bottom 111 and the frame 112 may be formed by processing a single metal or alloy plate, or may be integrated with each other by welding or the like. The bottom 111 is provided with drainage openings 111a and 111b. The frame portion 112 has a first portion 112a, a second portion 112b, a third portion 112c, a fourth portion 112d, and an inner surface 112e. In a plan view, the first portion 112a constitutes one end of the frame portion 112 in the second direction Y, the second portion 112b constitutes the other end of the frame portion 112 in the second direction Y, the third portion 112c constitutes one end of the frame portion 112 in the first direction X, and the fourth portion 112d constitutes the other end of the frame portion 112 in the first direction X. In a plan view, the inner surface 112e surrounds the battery group 102 and side spacer 103.

In this embodiment, the bottom 111 has a rectangular shape in a plan view, and the frame 112 has a square frame shape in a plan view, but this is not limited to this. The bottom 111 may have a polygonal shape, a circular shape, or an elliptical shape in a plan view. Similarly, the frame 112 may have a polygonal frame shape, a circular frame shape, or an elliptical frame shape in a plan view. Hereinafter, the direction in which the short sides of the bottom 111 extend is referred to as the first direction X, the direction in which the long sides of the bottom 111 extend is referred to as the second direction Y, and the direction perpendicular to the first direction X and the second direction Y is referred to as the third direction Z. In this embodiment, the third direction Z corresponds to the up-down direction, and viewing from the third direction Z corresponds to viewing from the plan view.

The battery group 102 is composed of multiple storage batteries 1 housed in the housing 101. In this embodiment, the battery group 102 is composed of a total of 24 storage batteries 1. In addition to the multiple storage batteries 1, the battery group 102 also has multiple internal connection members 121 and external connection members 122, 123 for connection to an external device. Each of the multiple internal connection members 121 is a member for electrically connecting adjacent storage batteries 1 to each other. The internal connection member 121 has, for example, a conductive portion connected to both adjacent storage batteries 1 and a protective portion for protecting the conductive portion. In this embodiment, the multiple internal connection members 121 are used to connect the multiple storage batteries 1 included in the battery group 102 in series, but this is not limited to this. The multiple storage batteries 1 may also be connected in parallel. Furthermore, the battery group 102 may be connected in both series and parallel. The external connection member 122 is located on one side of the first direction X, and the external connection member 123 is located on the other side of the first direction X. Additionally, the external connection members 122 and 123 are located on one side in the second direction Y.

The structure of the storage battery 1 will now be described in detail with reference to Figures 2 to 4. Figure 2 is a perspective view showing a partially cutaway portion of the storage battery according to this embodiment. As shown in Figure 2, the storage battery 1 is, for example, a lead-acid battery. In this embodiment, the storage battery 1 is, for example, a clad-type lead-acid battery equipped with clad electrodes. The storage battery 1 includes an electrode group 3, a positive terminal 5A, a negative terminal 5B, a water refill valve 6, and a case 7. The case 7 has a main body 8 and a lid 9. The main body 8 is a box-shaped battery container. The main body 8 is formed from a material such as polypropylene. The main body 8 contains the electrode group 3 and electrolyte. The main body 8 is composed of four side surfaces and a bottom. The corners formed by the bottom and side surfaces are rounded. The lid 9 covers the opening of the main body 8. The lid 9 is provided with a positive terminal 5A, a negative terminal 5B, and a water refill valve 6. In the battery group 102, the positive electrode terminal 5A and the negative electrode terminal 5B are each covered by either an internal connection member 121, an external connection member 122, or an external connection member 123 (see Figure 1). A water refill tap 6 is provided between the positive electrode terminal 5A and the negative electrode terminal 5B.

The electrode group 3 is an assembly of multiple electrode plates and includes multiple positive electrodes 10, multiple negative electrodes 12, and multiple separators 13. In the electrode group 3, the positive electrodes 10 and negative electrodes 12 are arranged alternately. A separator 13 is located between adjacent positive electrodes 10 and negative electrodes 12. Therefore, the positive electrodes 10, separators 13, and negative electrodes 12 are stacked in order in a predetermined direction. In this embodiment, in the electrode group 3, the negative electrodes 12 are arranged at the ends of the arrangement direction of the positive electrodes 10, negative electrodes 12, and separators 13 (hereinafter simply referred to as the "arrangement direction" or "stacking direction"). In addition, the assembly of the positive electrodes 10, negative electrodes 12, and separators 13 is also referred to as a battery electrode group (electrode plate group). When the electrode group 3 and electrolyte are housed in the main body 8, the electrolyte is present in the gap between the positive electrodes 10 and the separators 13, within the separators 13, etc. The arrangement direction (stacking direction) corresponds to the first direction X.

Figure 3(a) shows the positive electrode as viewed from a first direction, and Figure 3(b) is an enlarged cross-sectional view taken along line IIIb-IIIb in Figure 3(a). As shown in Figures 2 and 3(a) and (b), the positive electrode 10 is, for example, a clad positive electrode plate (second electrode plate). In the storage battery 1, each positive electrode 10 is electrically connected to a positive electrode terminal 5A. Each positive electrode 10 and the positive electrode terminal 5A are electrically connected by a positive electrode strap 17. The positive electrode 10 includes a current collector 14, multiple cylindrical bodies 15 (tubes) that house a portion of the current collector 14, positive electrode material 16 housed in the cylindrical bodies 15, and upper and lower connecting seats 21 and 22 attached to the current collector 14.

The current collector 14 has multiple cores 14a, connecting portions that connect the multiple cores 14a, and tabs 14c that protrude from the connecting portions. The current collector 14 is formed, for example, by casting. The constituent material of the current collector 14 may be any conductive material, such as a lead alloy such as a lead-calcium-tin alloy or a lead-antimony-arsenic alloy. The lead alloy may also contain selenium, silver, bismuth, etc.

The multiple cores 14a are rod-shaped portions extending in the third direction Z and are arranged in a row in the second direction Y. One end of each core 14a in the third direction Z is connected to a connecting portion (not shown) covered by the upper link seat 21. The other end of each core 14a in the third direction Z is fixed to the lower link seat 22. The length of each core 14a is, for example, 170 to 650 mm. The length of each core 14a may be 600 mm or less, or 450 mm or less. The connecting portion supports the core 14a and the tab 14c and extends in the second direction Y. When the positive electrode 10 is housed in the case 7, the connecting portion is located on the positive electrode terminal 5A side in the third direction Z. The tab 14c is a terminal portion protruding from the connecting portion in the third direction Z and connected to the positive electrode strap 17. In the third direction Z, the protruding direction of the tab 14c is opposite to the protruding direction of the core metal 14a. When the positive electrode 10 is housed in the case 7, the tab 14c is located on the lid 9 side in the third direction Z.

The multiple cylindrical bodies 15 are insulating members that make up a group of active material holding tubes (clad tubes). The group of active material holding tubes is a collection of cylindrical porous tubes, also known as "gauntlets." For this reason, each cylindrical body 15 has multiple holes. In this embodiment, the cylindrical bodies 15 have a uniform thickness, but this is not limited to this. Each cylindrical body 15 extends along the third direction Z and houses a corresponding core metal 14a. Each cylindrical body 15 is, for example, a resin molded product.

The positive electrode material 16, together with the metal core 14a, is packed inside the cylindrical body 15. Therefore, the metal core 14a and the positive electrode material 16 are housed in the cylindrical body 15. As shown in FIG. 3(b), the positive electrode material 16 surrounds the metal core 14a inside the cylindrical body 15. The positive electrode material 16 includes an active material. The active material includes both the active material after chemical formation and the raw material for the active material before chemical formation. The positive electrode material 16 contains the active material after chemical formation. The positive electrode material 16 after chemical formation includes, for example, the raw material for the positive electrode active material. In this embodiment, the positive electrode material 16 may include a positive electrode active material and an additive. Examples of the positive electrode active material include lead powder, red lead, etc. Examples of the additive include a carbon material or short reinforcing fibers, etc. The positive electrode active material after chemical formation is, for example, lead dioxide, etc.

The upper connecting seat 21 is an insulating structure attached to the connecting portion of the current collector 14 and covers the connecting portion when viewed from the third direction Z. The upper connecting seat 21 seals one end of each cylindrical body 15 in the third direction Z. For example, the upper connecting seat 21 is welded to each cylindrical body 15, but this is not limited to this. The upper connecting seat 21 and each cylindrical body 15 may be fixed to each other, for example, via an adhesive or the like. The upper connecting seat 21 is provided, for example, by welding an insulating resin member to the current collector 14. The lower connecting seat 22 is an insulating structure attached to the multiple core metals 14a of the current collector 14. The lower connecting seat 22 is attached to the current collector 14, for example, by inserting and fitting the core metals 14a of the current collector 14 into an insulating resin member. The lower connecting seat 22 seals the other end of each cylindrical body 15 in the third direction Z. As a result, the position of each cylindrical body 15 in the positive electrode 10 is fixed by the upper linking seat 21 and the lower linking seat 22. For example, the lower linking seat 22 is welded to each cylindrical body 15, but this is not limited to this. The lower linking seat 22 and each cylindrical body 15 may also be fixed to each other by, for example, an adhesive or the like.

Figure 4 is a plan view showing a negative electrode according to an embodiment. As shown in Figure 4, the negative electrode 12 is a negative electrode plate (first electrode plate) in the storage battery 1 and is electrically connected to the negative electrode terminal 5B. Each negative electrode 12 and the negative electrode terminal 5B are electrically connected by a negative electrode strap 18. The negative electrode 12 has a current collector 12a and a negative electrode material 12b. The current collector 12a is formed, for example, by casting, and has a negative electrode grid 12c and a lug 12d. The negative electrode grid 12c is the main body of the negative electrode 12 and holds the negative electrode material 12b. In this embodiment, the thickness of the portion of the negative electrode 12 where the negative electrode material 12b is held is greater than the thickness of the negative electrode grid 12c, but this is not limited to this. The negative electrode material 12b may contain a negative electrode active material and an additive. The negative electrode active material is, for example, spongy lead. Examples of additives include barium sulfate, a carbon material, lignin, or short reinforcing fibers. The ear 12d is a terminal portion that protrudes from the negative electrode grid 12c along the third direction Z and is connected to the negative electrode strap 18. The ear 12d and the negative electrode grid 12c do not overlap with each other in the first direction X. In this embodiment, the negative electrode grid 12c is covered with a separator 13. The negative electrode grid 12c has protrusions 12e and 12f. The protrusions 12e and 12f are arranged at a predetermined interval and are legs that protrude outward from the negative electrode grid 12c. The protrusions 12e and 12f protrude in a direction opposite to the protrusion direction of the ear 12d. In this embodiment, the protrusion direction of the ear 12d and the protrusion direction of the protrusions 12e and 12f are each perpendicular to the arrangement direction. Furthermore, the ears 12d and the negative electrode grid 12c do not overlap with each other in the arrangement direction.

Returning to Figure 2, the separator 13 is a battery component (battery separator) for preventing short-circuiting between the positive electrode 10 and the negative electrode 12. The separator 13 is not particularly limited as long as it provides electrical insulation between the positive electrode 10 and the negative electrode 12 while allowing ions to pass through and is resistant to oxidation on the positive electrode 10 side and reduction on the negative electrode 12 side. Materials for the separator 13 include glass fiber, resin, inorganic substances, etc. In this embodiment, the separator 13 covers the negative electrode grid 12c and the protrusions 12e and 12f of the negative electrode 12, and the edge 12d of the negative electrode 12 is exposed from the separator 13. When viewed from the first direction X, the aspect ratio of the dimension of the separator 13 along the second direction Y to the dimension of the separator 13 along the third direction Z is, for example, 1.4 or more and 4.0 or less. The aspect ratio may be 1.5 or greater and 3.8 or less, 1.8 or greater and 3.5 or less, or 2.0 or greater and 3.0 or less. Ribs may be provided on at least one of the front and rear surfaces of the separator 13. When viewed in the thickness direction of the separator 13, the ribs may extend linearly, wavy, or zigzag. When viewed in the thickness direction, the ribs may be dot-shaped, circular, elliptical, or polygonal.

Returning to FIG. 1 , the side spacer 103 is an insulating member disposed between the inner surface 112e of the housing 101 and the battery group 102, and has a rectangular frame shape in plan view. In plan view, the side spacer 103 is an enclosure (first enclosure) that contacts the inner surface 112e of the housing 101 and surrounds the battery group 102. The inner surface 103a of the side spacer 103 contacts the battery group 102. The side spacer 103 is a resin molded body made of, for example, polypropylene, polyvinyl chloride, or the like. The side spacer 103 may be deformable in its thickness direction. In this case, the side spacer 103 can be compressed by the housing 101 and the battery group 102. This allows the battery group 102 and side spacer 103 to be accommodated in the housing 101 without any gaps.

The thickness of the side spacer 103 is, for example, 1 mm or more. In this case, short circuits between the inner surface 112e and the battery group 102 can be effectively prevented. The thickness of the side spacer 103 may be, for example, 2 mm or more, 3 mm or more, 5 mm or more, or 6 mm or more. If the side spacer 103 is deformable, the thickness of the side spacer 103 after deformation may be, for example, 6 mm or more. The thickness of the side spacer 103 is adjusted according to the gap between the inner surface 112e and the battery group 102, but is, for example, 12 mm or less, 10 mm or less, or 8 mm or less, taking into account the proportion of the side spacer 103 within the housing 101.

The lower end (one end) of the side spacer 103 may or may not contact the bottom 111. From the perspective of suppressing expansion of the storage battery 1, the lower end of the side spacer 103 may be located lower than the electrode group 3 (see FIG. 2) included in the storage battery 1 (particularly, lower than the negative electrode grid 12c of the negative electrode 12 (see FIG. 4)). That is, in the third direction Z, one end of the side spacer 103 may be closer to the bottom 111 than the electrode group 3. Furthermore, from the perspective of suppressing expansion of the storage battery 1, the upper end (the other end) of the side spacer 103 may be higher than the electrode group 3 included in the storage battery 1 (particularly, higher than the negative electrode grid 12c of the negative electrode 12 (see FIG. 4)). That is, in the third direction Z, the other end of the side spacer 103 may be closer to the upper edge of the frame 112 than the electrode group 3. If the side spacer 103 has one or more communication holes extending in the third direction Z, the upper end of the side spacer 103 may be located below the lid 9 of the storage battery 1. In this case, water or other substances on the lid 9 reach the bottom 111 of the housing 101 through the communication holes and are discharged through the openings 111a and 111b.

In this embodiment, the side spacer 103 is fixed to the inner surface 112e via a fixing portion (not shown). The fixing portion is made of a material (adhesive material) that can adhere to both the side spacer 103 and the housing 101, such as an organic adhesive (including, for example, epoxy-based materials, silicone-based materials, acrylic-based materials, polyimide-based materials, etc.).

The side spacer 103 is composed of one or more plate-shaped members. In this embodiment, the side spacer 103 has a first plate-shaped member 131, a second plate-shaped member 132, a third plate-shaped member 133, and a fourth plate-shaped member 134, each of which has a substantially rectangular parallelepiped shape.

The first plate-shaped member 131 extends along the first direction X in a plan view and contacts the first portion 112a of the frame portion 112. The first plate-shaped member 131 is arranged in the second direction Y between the first portion 112a and the storage battery 1 on which the external connection member 122 is provided (and the storage battery 1 on which the external connection member 123 is provided). At least a portion of the first plate-shaped member 131 may be fixed to the first portion 112a via the above-mentioned fixing portion. One end of the first plate-shaped member 131 in the first direction X contacts the third plate-shaped member 133, and the other end of the first plate-shaped member 131 in the first direction X contacts the fourth plate-shaped member 134. The second plate-shaped member 132 extends along the first direction X in a plan view and contacts the second portion 112b of the frame portion 112. The second plate-shaped member 132 is located on the opposite side of the first plate-shaped member 131 in the second direction Y across the battery group 102. At least a portion of the second plate-shaped member 132 may be fixed to the second portion 112b via the fixing portion. One end of the second plate-shaped member 132 in the first direction X contacts the third plate-shaped member 133, and the other end of the second plate-shaped member 132 in the first direction X contacts the fourth plate-shaped member 134.

The third plate member 133 extends along the second direction Y in a plan view and contacts the third portion 112c of the frame portion 112. The third plate member 133 is arranged in the first direction X between the third portion 112c and the storage battery 1 on which the external connection member 122 is provided. At least a portion of the third plate member 133 may be fixed to the third portion 112c via the above-mentioned fixing portion. One end of the third plate member 133 in the second direction Y contacts the first portion 112a, and the other end of the third plate member 133 in the second direction Y contacts the second portion 112b. The fourth plate member 134 extends along the second direction Y in a plan view and contacts the fourth portion 112d of the frame portion 112. The fourth plate member 134 is arranged in the first direction X between the fourth portion 112d and the storage battery 1 on which the external connection member 123 is provided. At least a portion of the fourth plate-shaped member 134 may be fixed to the fourth portion 112d via the fixing portion. One end of the fourth plate-shaped member 134 in the second direction Y contacts the first portion 112a, and the other end of the fourth plate-shaped member 134 in the second direction Y contacts the second portion 112b.

The thickness of each of the first plate-shaped member 131 and the second plate-shaped member 132 corresponds to the dimension of the first plate-shaped member 131 and the second plate-shaped member 132 along the second direction Y. The thickness of each of the third plate-shaped member 133 and the fourth plate-shaped member 134 corresponds to the dimension of the third plate-shaped member 133 and the fourth plate-shaped member 134 along the first direction X. The thicknesses of the first plate-shaped member 131 to the fourth plate-shaped member 134 may be the same or different. Some of the first plate-shaped members 131 to the fourth plate-shaped member 134 may have the same thickness. The heights of the first plate-shaped member 131 to the fourth plate-shaped member 134 may also be the same or different. Some of the first plate-shaped members 131 to the fourth plate-shaped member 134 may have the same height. In other words, the thickness and height of the side spacer 103 may be uniform or non-uniform.

Next, an example of a manufacturing apparatus for manufacturing the battery pack 100 according to this embodiment will be described with reference to FIG. 5. FIG. 5 is a schematic diagram of the manufacturing apparatus for manufacturing the battery pack according to this embodiment.

As shown in FIG. 5 , the manufacturing apparatus 200 for the battery pack 100 has a housing holding unit 201, a side spacer placement unit 202, and a storage battery placement unit 203. The housing holding unit 201 is a mechanism for holding the housing 101 and includes, for example, a mounting table and an arm. The side spacer placement unit 202 is a mechanism for placing the side spacers 103 in the housing 101 and includes, for example, a robot arm. The side spacer placement unit 202 includes, for example, a transport unit for transporting the side spacers 103 and a holding unit for maintaining the orientation of the side spacers 103 within the housing 101. The storage battery placement unit 203 is a mechanism for placing the storage battery 1 in the housing 101. The storage battery placement unit 203 includes, for example, a transport unit for transporting the storage battery 1 and an adjustment unit for adjusting the position of the storage battery 1 within the housing 101.

Next, an example of a method for manufacturing the battery pack 100 according to this embodiment will be described with reference to Figures 6(a) to 6(c). Figures 6(a) to 6(c) are diagrams for explaining the method for manufacturing the battery pack.

First, as shown in FIG. 6(a), the side spacers 103 are accommodated in the housing 101 (first step). In the first step, the side spacer arranging section 202 arranges the side spacers 103 along the inner surface 112e of the housing 101, with the housing 101 held by the housing holding section 201. Specifically, the side spacer arranging section 202 accommodates each of the first to fourth plate-shaped members 131 to 134 in the housing 101 along the third direction Z. This forms an enclosure (first enclosure) that is composed of the side spacers 103 arranged along the inner surface 112e of the housing 101 and that contacts the inner surface 112e. In the first step, before the first to fourth plate-shaped members 131 to 134 are accommodated in the housing 101, an adhesive material for forming an adhesive portion may be provided on the inner surface 112e. In this case, in the first step, the side spacer 103 is fixed to the inner surface 112e of the housing 101. Note that the above-mentioned adhesive material may be applied in advance to at least one of the first plate member 131 to the fourth plate member 134.

Next, multiple storage batteries 1 are housed in the housing 101 along the third direction Z (second step). In the second step, the storage battery arrangement unit 203 first arranges multiple storage batteries 1 (multiple first storage batteries) along the inner surface 103a of the side spacer 103. As shown in FIG. 6(b), the storage battery arrangement unit 203 arranges a total of 16 storage batteries 1 along the inner surface 103a of the side spacer 103 so as to form an enclosure F (second enclosure) that is made up of the first storage batteries and contacts the side spacer 103. After the enclosure F is formed, the storage battery arrangement unit 203 then arranges multiple storage batteries 1 (second storage batteries) within the enclosure F. Here, the storage battery arrangement unit 203 arranges a total of eight storage batteries 1 within the enclosure F inside the housing 101. At this time, the storage batteries 1 forming the enclosure F may press the side spacer 103 against the frame portion 112 of the housing 101. As a result, as shown in Figure 6(c), a total of 24 storage batteries 1 and side spacers 103 are housed tightly within the housing 101.

Next, the multiple storage batteries 1 housed in the housing 101 are electrically connected to each other (third step). In the third step, either an internal connection member 121, an external connection member 122, or an external connection member 123 is connected to the positive electrode terminal 5A and the negative electrode terminal 5B (see Figure 2) of each storage battery 1. Note that the third step may be performed automatically by the manufacturing apparatus 200 or manually. Water is then supplied to each storage battery 1 via the water supply tap 6 (see Figure 2) of each storage battery 1. In this way, the battery pack 100 shown in Figure 1 is manufactured.

In the battery pack 100 according to the present embodiment described above, in a plan view, an insulating side spacer 103 is disposed between the battery group 102 and the inner surface 112e of the conductive housing 101. According to the manufacturing method for the battery pack 100 according to the present embodiment, first, an enclosure composed of the side spacer 103 is formed within the housing 101. Next, an enclosure F is formed, which is composed of multiple storage batteries 1 arranged along the inner surface 103a of the side spacer 103 and contacts the side spacer 103. The multiple storage batteries 1 are then disposed within the enclosure F. This prevents the side spacer 103 from being crushed by the storage batteries 1 in the third direction Z, for example, when the side spacer 103 is inserted into the housing 101. This ensures that the battery group 102 is well enclosed by the side spacer 103 in a plan view. Therefore, according to this embodiment, it is possible to prevent a short circuit between the inner surface 112e of the housing 101 and the storage batteries 1 included in the battery group 102.

In addition, in this embodiment, the gap between the inner surface 112e of the housing 101 and the battery pack 102 is filled with a side spacer 103. This makes it difficult for the storage battery 1 to move within the housing 101, even if the battery pack 100 is subjected to vibrations, for example.

In this embodiment, the thickness of the side spacer 103 may be 1 mm or more and 12 mm or less. In this case, it is possible to effectively prevent a short circuit between the inner surface 112e of the housing 101 and the storage batteries 1 included in the battery group 102. In addition, the proportion of the housing 101 occupied by the side spacer 103 can be reduced.

In this embodiment, in a plan view, the side spacer 103 contacts the inner surface 112e of the housing 101 and surrounds the battery group 102. This effectively prevents short circuits between the inner surface 112e of the housing 101 and the storage batteries 1 included in the battery group 102.

In this embodiment, the battery pack 100 may have a fastening portion that fastens the side spacer 103 to the inner surface 112e. In this case, the fastening portion fixes the side spacer 103 to the housing 101, preventing the side spacer 103 from protruding from between the housing 101 and the battery group 102. This makes it possible to more effectively prevent a short circuit between the inner surface 112e of the housing 101 and the storage battery 1 included in the battery group 102.

In this embodiment, in the first step, the side spacer 103 may be fixed to the inner surface 112e of the housing 101. In this case, it is possible to effectively prevent the side spacer 103 from shifting position before the enclosure F is formed.

Below, we will explain a modified version of the above embodiment with reference to Figures 7(a), (b) and 8(a), (b). In the following modified version, explanations of parts that overlap with the above embodiment will be omitted. Therefore, the following will mainly explain the parts that are different from the above embodiment.

Figure 7(a) is a schematic plan view showing a housing according to a modified example. The housing 101A shown in Figure 7(a) has a bottom portion 111, a frame portion 112, and a reinforcing portion 113. The reinforcing portion 113 is a plate-shaped portion that stands upright from the bottom portion 111 and extends along the first direction X in a plan view. The reinforcing portion 113 extends from the third portion 112c to the fourth portion 112d and is integrated with the frame portion 112. One end of the reinforcing portion 113 in the first direction X contacts the third portion 112c, and the other end of the reinforcing portion 113 in the first direction X contacts the fourth portion 112d. The reinforcing portion 113 is welded to the bottom portion 111 and the frame portion 112, for example.

Even when the housing 101A described above is used, the same effects as those of the above embodiment are achieved. In addition, the frame portion 112 (particularly the third portion 112c and fourth portion 112d) is less likely to bend.

7(b) is a schematic cross-sectional view showing the main parts of a housing and a side spacer according to another modified example. As shown in FIG. 7(b), the first plate-shaped member 131A of the side spacer 103A has multiple insulating members 140. The multiple insulating members 140 are stacked on top of each other in the direction in which the inner surface 112e of the housing 101 and the battery group 102 face each other. Each insulating member 140 is an insulating plate-shaped member having a substantially rectangular parallelepiped shape, and may correspond, for example, to the first plate-shaped member 131 in the above embodiment. In the side spacer 103A, at least one plate-shaped member other than the first plate-shaped member 131A may have multiple insulating members 140. The thickness of each insulating member 140 is, for example, 2 mm to 12 mm. Each plate-shaped member included in the side spacer 103A has, for example, 2 to 30 insulating members 140. In this case, the thickness of each plate-shaped member can be easily adjusted. From the standpoint of cost, etc., each plate-shaped member may have 10 or fewer insulating members 140. If each plate-shaped member has multiple insulating members 140, the thickness of each insulating member 140 may be the same as or different from each other.

Each insulating member 140 is fixed by multiple fixing portions 141. The fixing portions 141 are, for example, bands, staples, etc. In FIG. 7(b), each insulating member 140 is fixed by two fixing portions 141, but this is not limited to this. Three or more fixing portions 141 may be provided on the first plate-shaped member 131A. From the perspective of suppressing the concentration of force due to expansion of the storage battery 1, the fixing portions 141 may be provided below the electrode group 3 (see FIG. 2) included in the storage battery 1 (particularly, below the negative electrode grid 12c of the negative electrode 12 (see FIG. 4)) or above the electrode group 3 (particularly, above the negative electrode grid 12c).

Even when the side spacer 103A described above is used, the same effects as those of the above embodiment are achieved. In addition, the side spacer 103A can be formed, for example, by inserting a number of insulating members 140 corresponding to the size of the gap between the inner surface 112e and the battery group 102. Therefore, even when the type of housing 101 is limited (i.e., when the size of the housing 101 is restricted), a wide variety of battery packs can be manufactured. Furthermore, the side spacer 103A has fixing portions 141 that fix multiple insulating members 140 together. Therefore, the insulating members 140 do not protrude from between the housing 101 and the battery group 102, and the function of the side spacer 103A can be maintained satisfactorily.

Figure 8(a) is a schematic plan view showing a battery pack according to yet another modified example, and Figure 8(b) is an end view taken along line VIIIb-VIIIb in Figure 8(a). The housing 101B shown in Figures 8(a) and (b) has an additional spacer portion 114 in addition to a bottom portion 111 and a frame portion 112. The additional spacer portion 114 is a conductive member for narrowing the internal space of the housing 101B, and is, for example, a processed piece of metal plate or alloy plate. The additional spacer portion 114 is fixed to the bottom portion 111 and the fourth portion 112d of the frame portion 112 within the frame portion 112. In this modified example, the additional spacer portion 114 is welded to each of the bottom portion 111 and the frame portion 112. The additional spacer portion 114 may be welded to the bottom portion 111 and the first portion 112a, second portion 112b, and fourth portion 112d of the frame portion 112 so that an enclosed space is defined by the housing 101B and the additional spacer portion 114.

The additional spacer portion 114 has a first plate portion 114a extending from the bottom portion 111 in the third direction Z, and a second plate portion 114b extending from the tip of the first plate portion 114a toward the frame portion 112. The first plate portion 114a is a plate-shaped portion extending in the second direction Y in a plan view and has a roughly rectangular parallelepiped shape. The base end of the first plate portion 114a is welded to the bottom portion 111. One end of the first plate portion 114a in the second direction Y is welded to the first portion 112a, and the other end of the first plate portion 114a in the second direction Y is welded to the second portion 112b. The tip of the first plate portion 114a is located, for example, above the side spacer 103 and below the upper end of the frame portion 112. That is, the tip of the first plate portion 114a is located, for example, between the side spacer 103 and the edge of the frame portion 112 in the third direction Z. The surface of the first plate portion 114a contacts the fourth plate member 134 of the side spacer 103. The fourth plate member 134 may be fixed to the first plate portion 114a via a fixing portion (not shown). The second plate portion 114b is a plate portion having a substantially rectangular shape in a plan view, and is welded to the frame portion 112.

Even when the additional spacer portion 114 described above is used, the same effects as those of the above embodiment are achieved. In addition, the internal space of the housing 101B can be narrowed while suppressing cost increases compared to when a large number of side spacers 103 (plate-shaped members) are used. Furthermore, by having the side spacer 103 contact the additional spacer portion 114, it is possible to prevent a short circuit between the housing 101 and the battery group 102, even when the housing 101B has the additional spacer portion 114.

The battery pack, manufacturing method thereof, and battery pack manufacturing apparatus according to one aspect of the present disclosure are not limited to the above embodiment and the above modification. For example, in the above embodiment and the above modification, the manufacturing apparatus is used in the first step and the second step, but this is not limited to this. The manufacturing apparatus does not have to be used in at least one of the first step and the second step.

In the above embodiment and modified example, the storage battery is housed in the housing in the second step, but this is not limited to this. For example, in the first step, some of the multiple storage batteries (the third storage battery) may be housed in the housing. The third storage battery may be a storage battery contained in an enclosure that contacts the side spacer. In this case, the enclosure is composed of the first storage battery and the third storage battery. Alternatively, the third storage battery may be disposed inside the enclosure. If multiple third storage batteries are housed in the housing in the first step, some of the third storage batteries may be contained in the enclosure and the remaining third storage batteries may be disposed inside the enclosure in the second step. For example, by housing the third storage battery before housing the side spacers, the side spacers can be sandwiched between the third storage battery and the housing. Therefore, shifting of the position of the side spacers during the manufacture of the battery pack can be prevented without using fastening parts.

In the above embodiment and modified example, the second storage battery is housed in the housing after the first storage battery is housed in the housing in the second step, but this is not limited to this. For example, in the second step, some of the multiple second storage batteries may be housed in the housing before the enclosure containing the first storage battery is formed.

In the above embodiment and modified example, one end of the first plate member included in the side spacer contacts the third plate member, and the other end of the first plate member contacts the fourth plate member, but this is not limited to this. One end of the first plate member does not have to contact the third plate member, and the other end of the first plate member does not have to contact the fourth plate member. Similarly, one end of the second plate member does not have to contact the third plate member, and the other end of the second plate member does not have to contact the fourth plate member. Even in these cases, the side spacer is considered to be an enclosure as long as it surrounds the battery group in a plan view. Furthermore, one end of the third plate member does not have to contact the first portion of the housing, and the other end of the third plate member does not have to contact the second portion of the housing. Similarly, one end of the fourth plate member does not have to contact the first portion of the housing, and the other end of the fourth plate member does not have to contact the second portion of the housing.

1...storage battery, 3...electrode group, 5A...positive electrode terminal, 5B...negative electrode terminal, 6...water refill valve, 9...lid, 10...positive electrode, 12...negative electrode, 12a...current collector, 12b...negative electrode material, 12c...negative electrode grid (main body), 12d...lug, 12e...convex portion, 12f...convex portion, 13...separator, 14...current collector, 15...cylindrical body, 16...positive electrode material, 100...battery assembly, 101, 101A, 101B...housing, 102...battery group, 103, 103A...side spacer, 103a...inner surface, 111... Bottom, 111a, 111b...opening, 112...frame, 112e...inner surface, 113...reinforcing portion, 114...additional spacer portion, 121...internal connection member, 122, 123...external connection member, 131, 131A...first plate-shaped member, 132...second plate-shaped member, 133...third plate-shaped member, 134...fourth plate-shaped member, 140...insulating member, 141...fixing portion, 200...manufacturing apparatus, 201...casing holding portion, 202...side spacer arrangement portion, 203...storage battery arrangement portion, F...enclosure.

Claims (12)

a housing having a conductive base and a frame extending along an edge of the base ;
a battery group including a plurality of storage batteries housed in the housing, the plurality of storage batteries being in direct contact with each other ;
an insulating side spacer disposed between the battery group and an inner surface of the frame portion of the housing in a plan view;
Equipped with
In a plan view, the side spacer contacts the inner surface of the frame portion of the housing and surrounds the battery group. The battery pack described in claim 1, wherein the thickness of the side spacer is 1 mm or more in a plan view. The battery pack described in claim 1 or 2, having a fastening portion that fastens the side spacer to the inner surface. The battery pack described in any one of claims 1 to 3, wherein the side spacer has multiple insulating members stacked on top of each other in the direction in which the inner surface and the battery group face each other. The battery pack described in claim 4, wherein the side spacer has a fixing portion that fixes the multiple insulating members together. the housing has an additional spacer portion fixed to the bottom portion and the frame portion within the frame portion,
6. The battery pack according to claim 1, wherein the side spacer is in contact with the additional spacer portion. a first step of housing an insulating side spacer in a conductive housing;
a second step of housing a plurality of storage batteries in the housing;
Equipped with
the plurality of storage batteries include a plurality of first storage batteries and a plurality of second storage batteries;
In the first step, a first enclosure is formed, which is made up of the side spacer arranged along an inner surface of the housing and contacts the inner surface;
In the second step, a second enclosure is formed, the second enclosure including the plurality of first storage batteries arranged along an inner surface of the first enclosure and in contact with the first enclosure, and then at least some of the plurality of second storage batteries are arranged inside the second enclosure.
A method for manufacturing a battery pack. The method for manufacturing a battery pack according to claim 7, wherein in the first step, the side spacer is fixed to the inner surface of the housing. The method for manufacturing a battery pack described in claim 7 or 8, wherein in the first step, a third storage battery included in or disposed inside the second enclosure is housed in the housing. In the first step, the plurality of third storage batteries are housed in the housing;
The method for manufacturing a battery pack according to claim 9 , wherein in the second step, at least some of the third storage batteries are contained in the second enclosure. The method for manufacturing a battery pack described in any one of claims 8 to 10, wherein in the second step, some of the plurality of second storage batteries are housed in the housing before the second enclosure is formed. a side spacer arrangement section for arranging insulating side spacers on a conductive housing;
a battery arrangement section that arranges a plurality of batteries in the housing;
Equipped with
the plurality of storage batteries include a plurality of first storage batteries and a plurality of second storage batteries;
the side spacer arrangement portion arranges the side spacers along an inner side surface of the housing to form a first enclosure that is made up of the side spacers and that contacts the inner side surface;
The storage battery arrangement unit is
disposing the plurality of first batteries along an inner surface of the first enclosure to form a second enclosure containing the plurality of first batteries and in contact with the first enclosure;
disposing at least a portion of the plurality of second storage batteries within the second enclosure;
Battery pack manufacturing equipment.