Battery module

Abstract

In a battery module having a folded structure, insulation is ensured before and after the fold. [Solution] The battery module 1 comprises a cell group 3 in which a plurality of parallel blocks 5, each of which has a plurality of battery cells 4 connected in parallel to one another, are folded back in the longitudinal direction from one end 1a to the other end 1b and from the other end 1b to the first end 1a and connected in series, a first storage section 11 that houses the cell group 3 before folding back, a second storage section 12 that houses the cell group 3 after folding back, and a partition wall section 13 that separates the cell group 3 before and after folding back and has insulating properties.

Description

[Technical Field]

[0001] The present disclosure relates to a battery module. [Background technology]

[0002] A typical battery module has a cell group formed by connecting a plurality of parallel blocks, each block having a plurality of battery cells connected in parallel, in series from one end to the other in the longitudinal direction. In such a battery module, the positive and negative electrodes are located at opposite ends in the longitudinal direction and are spaced apart from each other, so it is necessary to wire the positive and negative electrodes using lead wires or the like so that one of the positive and negative electrodes is close to the other.

[0003] Patent Document 1 discloses a battery module with a folded structure in which a cell group is folded in the longitudinal direction. The folded cell group is made up of multiple parallel blocks that are folded in series in the longitudinal direction from one end to the other and from the other end to the first end. Because of this folded structure, the positive and negative electrodes are located at the same end in the longitudinal direction, eliminating the need for wiring materials such as lead wires. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-317209 Summary of the Invention [Problem to be solved by the invention]

[0005] In the folded structure of Patent Document 1, multiple parallel blocks are arranged adjacent to each other before and after the fold. Because a large potential difference can occur between the multiple parallel blocks before and after the fold, it is necessary to ensure insulation from the perspective of potential safety measures such as preventing short circuits.

[0006] An object of the present disclosure is to ensure insulation before and after folding in a battery module having a folded structure. [Means for solving the problem]

[0007] The present disclosure provides: a cell group in which a plurality of parallel blocks, each of which has a plurality of battery cells connected in parallel to one another, are connected in series by being folded back in the longitudinal direction from one end to the other end and from the other end to the one end; a first storage section that stores the cell group before folding; a second storage section that stores the folded cell group; a partition wall portion that separates the cell group before folding from the cell group after folding and has insulating properties; A battery module is provided. [Effects of the Invention]

[0008] According to the present disclosure, in a battery module having a folded structure, insulation can be ensured before and after the fold. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a battery module according to an embodiment. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a cross-sectional view of the battery module taken along line VV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The battery module of the present disclosure includes a cell group in which a plurality of parallel blocks, each of which has a plurality of battery cells connected in parallel to one another, are folded back in the longitudinal direction from one end to the other end and from the other end to the first end to be connected in series, a first storage section that houses the cell group before folding back, a second storage section that houses the cell group after folding back, and a partition wall section that separates the cell group before folding back from the cell group after folding back and that has insulating properties.

[0011] According to the above configuration, the cell groups before and after the folding are separated by the insulating partition wall portion, so that insulation before and after the folding can be ensured.

[0012] The first storage section, the second storage section, and the partition wall section may be integrated.

[0013] According to the above configuration, the number of parts can be reduced compared to when the first housing portion, the second housing portion, and the partition wall portion are separate bodies.

[0014] The first accommodating portion may have a recessed shape into which at least an end of the cell group before being folded is inserted, and the second accommodating portion may have a recessed shape into which at least an end of the cell group after being folded is inserted.

[0015] According to the above configuration, the first and second storage sections have recessed shapes into which at least the ends of the cell group are inserted, making it possible to easily position the plurality of battery cells.

[0016] The first accommodating section and the second accommodating section may be provided at opposite ends of the partition wall in a height direction, and may be configured such that the insertion directions of the cell groups are opposite to each other.

[0017] The above configuration ensures good moldability and strength. If, unlike the above configuration, the first and second storage sections are concentrated on one end of the partition wall in the height direction, the partition wall is erected so as to protrude relative to the first and second storage sections. In this case, depending on the thickness of the partition wall, there is a risk that moldability will be reduced or strength will not be ensured. Therefore, these problems are avoided.

[0018] The parallel connections and the series connections may be formed only by lead plates. The lead plates may be arranged to sandwich the cell group in the height direction.

[0019] According to the above configuration, the use of lead plates, which have a larger conductive area than lead wires, for electrical connection of the cell group reduces electrical resistance. In addition, since no separate electrical connection wiring is required other than the lead plates, the number of parts can be reduced.

[0020] The plurality of parallel blocks may be connected in series in a number of 40 or more. The battery module may have an effective operating voltage of 40V or more.

[0021] According to the above configuration, a large potential difference occurs before and after folding in the cell group, but since insulation is ensured before and after folding as described above, a large-capacity battery module can be provided safely.

[0022] Specific examples of the present disclosure will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions may be used as necessary. However, the use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present disclosure. Furthermore, parts with the same reference numerals appearing in multiple drawings indicate identical or equivalent parts or components. Furthermore, the embodiments described below illustrate specific examples of the technical ideas of the present disclosure and do not limit the present disclosure to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended for illustrative purposes only and are not intended to limit the scope of the present disclosure. Furthermore, the content described in one embodiment or example may also be applicable to other embodiments or examples. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity.

[0023] FIG. 1 shows a perspective view of a battery module 1 according to one embodiment.

[0024] [Application] The battery module 1 is applied, for example, to an emergency power source such as a battery backup unit (BBU), a power source for a traction motor of an electric vehicle, etc. However, the use of the battery module 1 is not particularly limited, and it can be used as a power source for various other electrical devices.

[0025] [Exterior] The battery module 1 has a box-shaped exterior case 2 that extends in the longitudinal direction. In Fig. 1, part of the exterior case 2 (the top surface in Fig. 1) is omitted to show the interior. Note that the exterior case 2 is shown schematically, and the exterior case 2 may have a handle for gripping, various connectors, etc.

[0026] [Battery cell placement] FIG. 2 shows a plan view of the battery module 1.

[0027] The battery module 1 has a cell group 3 consisting of a plurality of battery cells 4 (152 in this embodiment). In the cell group 3, a plurality of parallel blocks 5 (76 in this embodiment) are arranged side by side, with a plurality of battery cells 4 (two in this embodiment) connected in parallel to each other. The parallel blocks 5 are connected in series in the longitudinal direction of the battery module 1, folded back from one end 1a to the other end 1b and from the other end 1b to the one end 1a (see arrows A1, A2, A3). In other words, the battery module 1 has a folded structure. In FIG. 2, the cell group 3 on the left half is before folding, and the cell group 3 on the right half is after folding.

[0028] In this embodiment, the cell group 3 is electrically connected in 2 parallel and 76 series, and has an effective voltage of 40 V or more. In particular, when 40 or more parallel blocks 5 are connected in series and / or the effective operating voltage of the battery module 1 is 40 V or more, a large potential difference occurs in the cell group 3 before and after folding, and the insulating properties of the partition wall 13 described below function effectively. However, these numbers are not particularly limited and can be changed as appropriate depending on the required design.

[0029] [Cell holder]

[0030] Fig. 3 shows an exploded top perspective view of the cell holder 6. Fig. 4 shows an exploded bottom perspective view of the cell holder 6. Note that Figs. 3 and 4 show only two of the multiple battery cells 4 for clarity of illustration.

[0031] The battery module 1 has a cell holder 6 that houses the cell group 3. The cell holder 6 has a main body 10, a first lid body 21, and a second lid body 22.

[0032] The main body 10 has a first storage section 11 that at least partially accommodates the cell group 3 before folding, a second storage section 12 that at least partially accommodates the cell group 3 after folding, and an insulating partition wall 13 that separates the cell groups 3 before and after folding. In this embodiment, the first storage section 11, the second storage section 12, and the partition wall 13 are made of an insulating material such as synthetic resin, and are integrated to form the main body 10.

[0033] The first housing section 11 has a recessed shape into which at least the end of the cell group 3 before folding is inserted. In the example shown, the first housing section 11 has a plurality of bottomed cylindrical structures that accommodate the lower half in the height direction of each of the plurality of battery cells 4. In the first housing section 11, the plurality of battery cells 4 are arranged in a staggered pattern along the longitudinal direction.

[0034] The first housing section has a rib 11a that rises on the side opposite the cell group 3. A current collecting structure including an insulating sheet, a current collecting plate, and a lead plate 11b is configured inside the rib 11a. The rib 11a is positioned to separate the multiple battery cells 4 into groups of four. Two of the four battery cells 4 are arranged facing the same direction up and down, and these two battery cells 4 form a parallel block 5. In other words, the lead plate 11b connects the battery cells 4 in parallel two by two within the area separated by the rib 11a to form two parallel blocks 5, and also forms a series connection between the two parallel blocks 5.

[0035] The second housing section 12 has a recessed shape into which at least the end of the folded cell group 3 is inserted. In the example shown, the second housing section 12 has a plurality of bottomed cylindrical structures that accommodate the upper half in the height direction of each of the plurality of battery cells 4. In the second housing section 12, the plurality of battery cells 4 are arranged in a staggered pattern along the longitudinal direction.

[0036] The second housing section has a rib 11a that rises on the side opposite the cell group 3. A current collecting structure including an insulating sheet, a current collecting plate, and lead plates 12b is configured inside the rib 12a. The ribs 12a are arranged in positions that separate the multiple battery cells 4 into groups of four, excluding both longitudinal ends. Two of the four battery cells 4 are arranged facing the same direction up and down, and these two battery cells 4 form a parallel block 5 (see Figure 2). In other words, the lead plates 12b connect the battery cells 4 in parallel two by two within the area separated by the rib 12a to form two parallel blocks 5, and also form a series connection between the two parallel blocks 5.

[0037] Fig. 5 is a cross-sectional view taken along line VV of the battery module in Fig. 1. Note that in Fig. 5, the exterior case 2 is not shown.

[0038] The partition wall 13 is an insulating plate-like portion extending in the height and length directions. The partition wall 13 is disposed between the first housing portion 11 and the second housing portion 12, and separates the cell group 3 before and after folding.

[0039] The first storage section 11 and the second storage section 12 are provided at opposite ends in the height direction of the partition wall section 13, and are configured so that the insertion directions of the cell group 3 are opposite to each other. In the example shown, the first storage section 11 is arranged on the lower end side of the partition wall section 13, and the second storage section 12 is arranged on the upper end side of the partition wall section 13. The insertion direction of the cell group 3 into the first storage section 11 is downward, and the insertion direction of the cell group 3 into the second storage section 12 is upward.

[0040] The first lid body 21 is provided to correspond to the first storage section 11, and has a recessed shape into which at least the end of the cell group 3 before being folded is inserted. In the example shown, the first lid body 21 has a plurality of bottomed cylindrical structures that accommodate the upper half of each of the plurality of battery cells 4 in the height direction.

[0041] 2 to 5, the first lid 21 has a rib 21a that rises on the side opposite the cell group 3. A current collecting structure including an insulating sheet, a current collecting plate, and lead plates 21b is configured inside the rib 21a. The ribs 21a are arranged in positions that separate the multiple battery cells 4 into groups of four, excluding both longitudinal ends. Two of the four battery cells 4 are arranged facing the same direction up and down, and these two battery cells 4 form a parallel block 5. In other words, the lead plates 21b connect the battery cells 4 in parallel two by two within the range separated by the rib 21a to form two parallel blocks 5, and also form a series connection between the two parallel blocks 5.

[0042] The second lid body 22 is provided to correspond to the second storage section 12 and has a recessed shape into which at least the end of the folded cell group 3 is inserted. In the example shown, the second lid body 22 has a plurality of bottomed cylindrical structures that accommodate the lower half of each of the plurality of battery cells 4 in the height direction.

[0043] The second lid 22 has a rib 22a that rises on the side opposite the cell group 3. A current collecting structure including an insulating sheet, a current collecting plate, and lead plates 22b is configured inside the rib 22a. The rib 22a is positioned to separate the multiple battery cells 4 into groups of four. Two of the four battery cells 4 are arranged facing the same direction up and down, and these two battery cells 4 form a parallel block 5. In other words, the lead plates 22b connect the battery cells 4 in parallel two by two within the area separated by the rib 22a to form two parallel blocks 5, and also form a series connection between the two parallel blocks 5.

[0044] Lead plates 12b, 21b are bent laterally to form negative and positive terminals 7, 8 at one longitudinal end 1a of battery module 1. Screws are attached to the negative and positive terminals 7, 8, respectively, and they are electrically connected to other members via screw fastening.

[0045] At the other longitudinal end 1b of the battery module 1, the lead plate 21b of the first lid 21 and the lead plate 12b of the second housing section 12 are connected via a connecting lead plate 13a (see FIG. 2). The connecting lead plate 13a connects the cell groups 3 before and after the fold, and is arranged across the partition wall 13 in plan view. These lead plates 12b, 13a, and 21b are electrically connected by screw fastening.

[0046] In this embodiment, the parallel and series connections are made only by lead plates 11b, 12b, 13a, 21b, and 22b arranged to sandwich the cell group 3 in the height direction. In other words, no separate electrical connection wiring is provided on the side surfaces of the cell group 3, etc.

[0047] [Action and effect] The battery module 1 according to the above embodiment can achieve the following advantageous effects.

[0048] Since the cell groups 3 before and after the folding are separated by the insulating partition wall portion, insulation between the plurality of parallel blocks 5 before and after the folding can be ensured.

[0049] Since the first storage section 11, the second storage section 12, and the partition wall section 13 are integrated, the number of parts can be reduced compared to when they are separate bodies.

[0050] Since the first housing portion 11 and the second housing portion 12 have a recessed shape into which at least the end of the cell group 3 is inserted, the positioning of the plurality of battery cells 4 can be facilitated.

[0051] The first storage section 11 and the second storage section 12 are provided at opposite ends of the partition wall section 13 in the height direction, and the insertion directions of the cell groups 3 are opposite to each other, ensuring good moldability and strength of the main body 10. If, unlike the present embodiment, the first storage section 11 and the second storage section 12 were provided concentrated on one end of the partition wall section in the height direction, the partition wall section 13 would be erected so as to protrude relative to the first storage section 11 and the second storage section 12. In this case, depending on the thickness of the partition wall section 13, there is a risk that moldability will decrease or strength will not be ensured. Therefore, efforts are made to avoid these problems.

[0052] The parallel and series connections are made only with lead plates 11b, 12b, 13a, 21b, and 22b arranged to sandwich the cell group 3 in the height direction, which results in a larger conductive area and reduced electrical resistance compared to lead wires.In addition, no separate electrical connection wiring is required for the electrical connection of the cell group 3 other than the lead plates 11b, 12b, 13a, 21b, and 22b, which reduces the number of parts.

[0053] Since the multiple parallel blocks 5 are connected in series with 40 or more blocks (76 in series in this embodiment), a large potential difference occurs before and after folding. However, as described above, insulation is ensured before and after folding, so a large-capacity battery module 1 can be provided safely.

[0054] Specific embodiments of the present disclosure and their modified examples have been described above, but the present disclosure is not limited to the above embodiments and can be implemented with various modifications within the scope of the present invention.

[0055] The present disclosure may include the following aspects. (Aspect 1) a cell group in which a plurality of parallel blocks, each of which has a plurality of battery cells connected in parallel to one another, are connected in series by being folded back in the longitudinal direction from one end to the other end and from the other end to the one end; a first storage section that stores the cell group before folding; a second storage section that stores the folded cell group; a partition wall portion that separates the cell group before folding from the cell group after folding and has insulating properties; A battery module comprising: (Aspect 2) 2. The battery module according to claim 1, wherein the first housing portion, the second housing portion, and the partition wall portion are integrated together. (Aspect 3) the first accommodating portion has a recessed shape into which at least an end of the cell group before being folded is inserted, 3. The battery module according to claim 1, wherein the second housing portion has a recessed shape into which at least an end of the folded cell group is inserted. (Aspect 4) A battery module as described in aspect 3, wherein the first storage section and the second storage section are provided at opposite ends of the partition wall section in the height direction and are configured so that the insertion directions of the cell groups are opposite to each other. (Aspect 5) 5. The battery module of any one of aspects 1 to 4, wherein the parallel connections and the series connections are formed only by lead plates. (Aspect 6) 6. The battery module according to claim 5, wherein the lead plates are arranged to sandwich the cell group in the height direction. (Aspect 7) 7. The battery module according to any one of aspects 1 to 6, wherein the plurality of parallel blocks include 40 or more parallel blocks connected in series. (Aspect 8) Aspect 8. The battery module of any one of aspects 1 to 7, wherein the effective operating voltage is 40 V or more. [Explanation of symbols]

[0056] 1 Battery Module 1a one end 1b other end 2 outer case 3 Cell Group 4 battery cells 5 Parallel Blocks 6 Cell Holder 7 Negative terminal 8 Positive terminal 10 Main Unit 11 First storage section 11a Rib 11b reed plate 12 Second storage section 12a Rib 12b reed plate 13 Partition wall 13a reed plate 21 First lid 21a Rib 21b lead plate 22 Second lid 22a Rib 22b reed plate

Claims

1. a cell group in which a plurality of parallel blocks, each of which has a plurality of battery cells connected in parallel to one another, are connected in series by being folded back in the longitudinal direction from one end to the other end and from the other end to the one end; a first storage section that stores the cell group before folding; a second storage section that stores the folded cell group; a partition wall portion that separates the cell group before folding from the cell group after folding and has insulating properties; Equipped with the first accommodating portion has a recessed shape into which at least an end portion of the cell group before being folded is inserted, the second accommodating portion has a recessed shape into which at least an end of the folded cell group is inserted, The first and second storage sections are provided at opposite ends of the partition wall in a height direction, and are configured so that the insertion directions of the cell groups are opposite to each other.

2. The battery module according to claim 1 , wherein the first housing portion, the second housing portion, and the partition wall portion are integrated together.

3. 3. The battery module according to claim 1, wherein the parallel connections and the series connections are formed only by lead plates.

4. The battery module according to claim 3 , wherein the lead plates are arranged to sandwich the cell group in a height direction.

5. The battery module according to claim 1 or 2, wherein the plurality of parallel blocks are 40 or more in number and are connected in series.

6. 3. The battery module according to claim 1, wherein the effective operating voltage is 40 V or more.

Images