Battery pack

Abstract

To improve the protection of battery packs. [Solution] The battery pack 1 consists of multiple single cells 2, each having a first side surface 10 facing a predetermined first direction D1 and a second side surface 20 facing a second direction D2 opposite to the first direction D1, arranged side by side with their first side surface 10 and second side surface 20 facing each other. Each of the multiple single cells 2 is provided with a first terminal 11 and a second terminal 21. The first terminal 11 is provided on the first side surface 10. The second terminal 21 protrudes from the second side surface 20 and is electrically connected in series with the first terminal 11 with the first side surface 10 facing the second side surface 20 spaced apart from the second side surface 20 in the second direction D2.

Description

Technical Field

[0001] This case relates to a battery pack in which single cells are arranged in parallel.

Background Art

[0002] In large-capacity batteries such as vehicle drive batteries, a plurality of battery packs are accommodated. In each battery pack (also referred to as a "module"), a plurality of single cells (also referred to as "cells") arranged in parallel are modularized by being connected in series. As one such battery pack, for example, Patent Document 1 proposes a battery pack provided with a bus bar for electrically connecting a plurality of single cells.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a plurality of single cells arranged in parallel in a battery pack are in contact with or close to each other, heat tends to be easily transferred between adjacent single cells. Therefore, when one single cell in the battery pack generates excessive heat, there is a risk of causing a chain reaction of temperature rise in other single cells due to the heat generation. Therefore, there is room for improvement in enhancing the protection of the battery pack.

[0005] The battery pack of this case was devised in view of such problems, and one of its purposes is to enhance the protection of the battery pack. Note that, not limited to this purpose, it is also another purpose of this case to exhibit an operational effect derived from each configuration shown in the "Mode for Carrying Out the Invention" described later and not achievable by the conventional technology.

Means for Solving the Problems

[0006] The disclosed battery pack can be realized in the following embodiments (examples of application) and solves at least some of the above-mentioned problems. Each of the embodiments from Embodiment 2 onward is an additional embodiment that can be appropriately selected and each of the embodiments is optional. None of the embodiments from Embodiment 2 onward disclose any embodiments or configurations that are essential to this case.

[0007] Embodiment 1. The disclosed battery pack comprises a plurality of single cells, each having a first side facing a predetermined first direction and a second side facing a second direction opposite to the first direction, arranged side by side with their first and second sides facing each other. Each of the plurality of single cells is provided with a first terminal and a second terminal. The first terminal is provided on the first side. The second terminal protrudes from the second side and is electrically connected in series with the first terminal, with the first side facing the second side spaced apart from the second side in the second direction.

[0008] Embodiment 2. In Embodiment 1 described above, it is preferable that the first terminal has a protruding terminal that protrudes from the first side surface.

[0009] Embodiment 3. In Embodiment 2 described above, it is preferable that the tip of the convex terminal has a recess into which the tip of the second terminal is inserted and removed, and that the convex terminal and the second terminal are electrically connected in series when the tip is inserted into the recess. Embodiment 4. In any one of embodiments 1 to 3 described above, the first terminal has a recessed terminal that is recessed from the first side surface and has a tip of the second terminal that can be inserted into or removed, and it is preferable that the recessed terminal and the second terminal are electrically connected in series when the tip of the second terminal is inserted into the recessed terminal. In this case, it is preferable that the dimension obtained by subtracting the recessed dimension of the recessed terminal (relative to the first side surface) from the convex dimension (protruding dimension of the second terminal relative to the second side surface) is equal to the distance between the first side surface and the second side surface.

[0010] Embodiment 5. In Embodiment 4 described above, it is preferable that the second terminal is provided in a tapered shape that narrows towards the convex tip, and the concave terminal is provided in an inverse tapered shape corresponding to the tapered shape. Embodiment 6. In any one of embodiments 1 to 5 described above, it is preferable that the first side surface and the second side surface are rectangular in shape, surrounded by a pair of long sides and a pair of short sides, and that the first terminal and the second terminal are provided extending in the direction along the long sides.

[0011] Embodiment 7. In any one of embodiments 1 to 6 described above, it is preferable that the battery pack is provided with a spacer attached to at least one of the first side and the second side, and interposed between the first side and the second side.

[0012] Embodiment 8. In Embodiment 7 described above, the first side surface and the second side surface are each rectangular in shape, surrounded by a pair of long sides and a pair of short sides, and the spacer is preferably formed such that, when viewed from the first or second direction, the dimension in the direction along the short sides is larger than the dimension in the direction along the long sides. Embodiment 9. In Embodiment 7 or 8 above, it is preferable that the spacer comprises a first spacer attached to the first side surface and a second spacer attached to the second side surface, and that the first spacer and the second spacer are fitted together.

[0013] Embodiment 10. In any one of embodiments 7 to 9 above, it is preferable that the first side surface and the second side surface are rectangular in shape, and the spacers are arranged at each of the diagonal corners of the first side surface and the second side surface. Embodiment 11. In any one of embodiments 7 to 10 described above, it is preferable that the spacer includes an insulating material. [Effects of the Invention]

[0014] According to the disclosed battery pack, by simply connecting single cells in series, the first side and the second side can be separated from each other in a predetermined direction, and the protection of the battery pack can be enhanced.

Brief Description of the Drawings

[0015] [Figure 1] It is a cross-sectional view schematically showing a battery pack of the first form according to an embodiment. [Figure 2] It is a perspective view showing one of two adjacent single cells in a battery pack of the first form according to an embodiment. [Figure 3] It is a perspective view showing the other of two adjacent single cells in a battery pack of the first form according to an embodiment. [Figure 4] It is a perspective view showing a modification of FIG. 2. [Figure 5] It is a perspective view showing a modification of FIG. 3. [Figure 6] It is a cross-sectional view showing two adjacent single cells in a battery pack of the first form according to an embodiment. [Figure 7] It is a cross-sectional view schematically showing two adjacent single cells in a battery pack of the second form according to an embodiment. [Figure 8] It is a perspective view showing a spacer of a battery pack of the second form according to an embodiment. [Figure 9] It is a schematic diagram explaining the arrangement of terminal spacers in one of two adjacent single cells in a battery pack of the second form according to an embodiment. [Figure 10] It is a schematic diagram explaining the arrangement of terminal spacers in the other of two adjacent single cells in a battery pack of the second form according to an embodiment. [Figure 11] It is a cross-sectional view schematically showing two adjacent single cells in a battery pack of the third form according to an embodiment.

Embodiments for Carrying Out the Invention

[0016] Referring to the drawings, embodiments of the assembled battery will be described. The following embodiments are merely examples, and there is no intention to exclude various modifications and applications of technologies not explicitly stated in the following embodiments. Each configuration of the embodiments can be implemented with various modifications without departing from their gist. Also, selection can be made as necessary, or they can be combined as appropriate.

[0017] The assembled battery of this embodiment is used, for example, as a battery for vehicle drive. In the battery for vehicle drive, a plurality of assembled batteries are housed to ensure battery capacity, and an assembled battery in which a plurality of single cells are connected in series is used to ensure voltage. The type of vehicle on which such a battery is mounted is not particularly limited. For example, it can be applied to an electric vehicle (EV, Electric Vehicle), a hybrid vehicle (hybrid electric vehicle, HEV, Hybrid Electric Vehicle), a plug-in hybrid vehicle (plug-in hybrid electric vehicle, PHEV, Plug-in Hybrid Electric Vehicle), etc. as a battery for vehicle drive. A plug-in hybrid vehicle means a hybrid vehicle capable of external charging of the battery or external power supply from the battery. A plug-in hybrid vehicle is provided with a charging port (inlet) for inserting a charging cable through which power is supplied from an external charging facility and an outlet for external power supply.

[0018] Regarding the directions used in the description of this embodiment, they are defined as follows. The direction of gravity is taken as downward, and the opposite is upward (「UP」 in the figure). For the directions orthogonal to these vertical directions, four directions of a predetermined first direction (「D1」 in the figure), second direction (「D2」 in the figure), third direction (「D3」 in the figure), and fourth direction (「D4」 in the figure) are used. The first direction and the second direction face opposite to each other, and the third direction and the fourth direction face opposite to each other. Also, the first direction and the second direction and the third direction and the fourth direction are orthogonal to each other.

[0019] To give an example of associating the four directions (front, back, left, and right) with the first, second, third, and fourth directions, the first direction is forward, the second direction is backward, the third direction is left, and the fourth direction is right. The direction along which both the first and second directions are aligned is also called the alignment direction (D12 in Figure 8, predetermined direction), and the direction along which both the third and fourth directions are aligned is also called the width direction (D34 in Figure 8). If the first direction is forward and the second direction is backward, the alignment direction corresponds to the front-to-back direction, and if the third direction is left and the fourth direction is right, the width direction corresponds to the left-to-right direction. Viewing from the first or second direction is called a parallel-direction view (or predetermined-direction view).

[0020] [I. One Embodiment] Figure 1 is a schematic cross-sectional view showing a first embodiment of a battery pack 1 according to one of the embodiments. Figures 2 and 3 are perspective views showing one of two adjacent single cells 2 in the first embodiment of the battery pack 1, with one of the two adjacent single cells 2 shown in Figure 2 and the other in Figure 3. Figures 4 and 5 correspond to modified examples of Figures 2 and 3, respectively. Figure 6 is a cross-sectional view showing two adjacent single cells 2 in a first embodiment of a battery pack 1 according to one of the embodiments.

[0021] Figures 7 to 9 illustrate a second embodiment of the battery pack 1A according to one embodiment. Figure 7 is a schematic cross-sectional view showing two adjacent single cells 2 in the second embodiment of the battery pack 1A. Figure 8 is a perspective view showing the spacer 30' of the second embodiment of the battery pack 1A. Figures 9 and 10 are schematic diagrams showing one of two adjacent single cells 2 in the second embodiment of the battery pack 1A, with one of the two adjacent single cells 2 shown in Figure 9 and the other in Figure 10. Figure 11 is a schematic cross-sectional view showing two adjacent single cells 2 in a third embodiment of a battery pack 1B according to one embodiment.

[0022] [1. Structure] As shown in Fig. 1, in the assembled battery 1, a plurality (eight in Fig. 1) of single cells 2 are arranged in parallel along the arrangement direction. The plurality of single cells 2 illustrated in Fig. 1 are supported by brackets 9 such that both sides between the ends in the first direction and the ends in the second direction are sandwiched. Each of the plurality of single cells 2 is a sealed unit cell in which an element 3 (only one location is labeled in Fig. 1) is housed in a case 4 (only one location is labeled in Fig. 1).

[0023] The element 3 is a power generation element formed by laminating sheet-like electrode plates and the like, and contains an organic solvent-based electrolyte solution in which an electrolyte related to charge and discharge reaction is dissolved inside. The shape of the element 3 is formed, for example, in a laminated shape (sheet shape), a cylindrical shape (rolled shape), an oval cylindrical shape (the power generation element is flattened and wound in an elliptical vortex shape), etc. The element 3 illustrated in Fig. 1 is in an oval cylindrical shape, and a negative electrode terminal 11 (first terminal) and a positive electrode terminal 21 (second terminal) are connected. Each of the plurality of single cells 2 is provided with terminals 11, 21.

[0024] As shown in Figs. 2 and 3, the case 4 is in a rectangular parallelepiped shape. In this case 4, a pair of side surfaces 10, 20 face the arrangement direction, and a pair of side surfaces 10, 20 (so-called "long side surfaces") larger than the other four surfaces facing the vertical direction and the width direction are provided. Regarding the dimensions of the case 4, if the dimension along the arrangement direction is the "thickness dimension X", the dimension along the vertical direction is the "height dimension Y", and the dimension along the width direction is the "lateral dimension Z", the inequality "X < Y < Z, XY < XZ < YZ" holds. That is, each of the side surfaces 10, 20 has a long side dimension of the lateral dimension Z and a short side dimension of the height dimension Y, and forms a rectangular shape surrounded by a pair of long sides and a pair of short sides.

[0025] Of the pair of side surfaces 10, 20, one is the first side surface 10 facing the first direction, and the other is the second side surface 20 facing the second direction. In the battery pack 1 illustrated in Figure 1, the arrangement of terminals 11 and 21 differs between the odd-numbered first cell 2A (one of two adjacent cell 2s in the row) and the even-numbered cell 2B (the other of two adjacent cell 2s in the row).

[0026] In the first single cell 2A, the negative terminal 11 is located at the bottom of the first side surface 10 (bottom left in Figure 1), and the positive terminal 21 is connected to the top of the second side surface 20 (top right in Figure 1). On the other hand, in the second single cell 2B, the negative terminal 11 is located at the top of the first side surface 10 (top left in Figure 1), and the positive terminal 21 is connected to the bottom of the second side surface 20 (bottom right in Figure 1). Except for the first side surface 10 of the single cell 2 located at the end in the first direction (left end in Figure 1) and the second side surface 20 of the single cell 2 located at the end in the second direction (right end in Figure 1), the single cell 2 are arranged side by side in the battery pack 1 with the first side surface 10 and the second side surface 20 facing each other.

[0027] In the battery pack 1 in which the above-described single cells 2A and 2B are arranged side by side, the first side surface 10 of the first single cell 2A and the second side surface 20 of the second single cell 2B are facing each other, and the two single cells 2A and 2B are arranged next to each other. By connecting the negative terminal 11 on the first cell 2A and the positive terminal 21 on the second cell 2B, the parallel-arranged cell 2A and 2B (multiple cell 2s) are electrically connected in series.

[0028] If multiple individual cells in a battery pack are arranged side-by-side and are in contact with or close to each other, heat is easily transferred between adjacent cells. Therefore, if one cell overheats, it can cause a chain reaction of temperature increases in the other cells, potentially compromising the protective capabilities of the battery pack. Therefore, the battery pack 1 of this embodiment is provided with a positive terminal 21 protruding from at least the second side surface 20, and a configuration is used in which the terminals 11 and 21 are electrically connected in series when the individual cells 2 are spaced apart. In other words, terminals 11 and 21 are provided on the side surfaces 10 and 20 to structurally prevent contact or proximity between the individual cells 2.

[0029] The first embodiment of the battery pack 1 according to this embodiment will be described below, followed by the second and third embodiments as modified examples. [1-1. First form] First, the first form of battery pack 1 will be explained with reference to Figures 2 to 6. In the first form of the battery pack 1, as shown in Figures 3 and 6, a recessed terminal 12 is provided as the negative terminal 11. The recessed terminal 12 is recessed from the first side surface 10. As shown in Figure 6, the tip 22 of the positive terminal 21 is provided in the recessed terminal 12 so as to be insertable and removable. With the tip 22 of the positive terminal 21 inserted into the recessed terminal 12, the recessed terminal 12 and the positive terminal 21 are electrically connected in series.

[0030] Here, the protruding dimension of the positive terminal 21 relative to the second side surface 20 is defined as "convex dimension L1," and the recessed dimension of the concave terminal 12 relative to the first side surface 10 is defined as "concave dimension L2." Furthermore, the distance between the first side surface 10 and the second side surface 20 in the direction of alignment is defined as "separation dimension L3." This separation dimension L3 can also be said to be the distance between the single cells 2A and 2B in the direction of alignment. The above-mentioned convex dimension L1, concave dimension L2, and separation dimension L3 satisfy the equation "L1-L2=L3" (i.e., the dimension obtained by subtracting the concave dimension L2 from the convex dimension L1 is equal to the separation dimension L3). In other words, the size of the convex and concave dimensions is set such that the positive terminal 21 protrudes more than the recess of the concave terminal 12, so that adjacent single cells 2A and 2B in the direction of alignment cannot be placed close together with a separation dimension shorter than L3. In this way, the close placement of single cells 2A and 2B is structurally restricted by the shape of terminals 12 and 21.

[0031] As shown in Figure 2, the positive terminal 21 is provided in a tapered shape that narrows towards the convex tip (the right end in Figure 2). The tapered shape here refers to a shape in which the area of ​​the cross-section along the vertical and width directions becomes smaller towards the second direction, and can also be described as a shape that widens towards the base (first direction). Figure 2 illustrates a positive terminal 21 that is a truncated pyramidal shape with a rectangular cross-section along the vertical and width directions. However, the positive terminal 21 may also be a truncated pyramidal shape with a polygonal (but not rectangular) cross-section along the vertical and width directions, or an elliptical truncated cone shape.

[0032] On the other hand, as shown in Figure 3, the recessed terminal 12 is provided in an inverse taper shape corresponding to the taper shape of the positive terminal 21 (see Figure 2). The inverse taper shape referred to here is the shape obtained by replacing "second direction" in the above-mentioned explanation of the taper shape with "first direction". The inverse taper shape is a shape in which, in a cross-section along the vertical and width directions, the area of ​​the cavity portion that receives the positive terminal 21 becomes smaller as it moves towards the second direction, and can be said to be a shape that widens as it moves towards the first direction.

[0033] As shown in Figure 2, the positive terminal 21 extends along the long side of the second side surface 20 and can be described as a protrusion. Figure 2 shows an example in which a single positive terminal 21 extends from the lower side of the second side surface 20. A recessed terminal 12, which will be described next, is positioned at the location corresponding to this positive terminal 21. As shown in Figure 3, the recessed terminal 12 extends along the long side of the first side surface 10 and is formed in a groove shape. Figure 3 shows an example in which one recessed terminal 12 extends from the lower side of the first side surface 10.

[0034] Furthermore, as shown in Figures 2 and 6, the first form of the battery pack 1 has a spacer 30 interposed between the first side surface 10 and the second side surface 20. As shown in Figure 6, the spacer 30 is formed to have dimensions in the alignment direction that are equal to or approximately equal to the spacing dimension L3. The material and components of the spacer 30 are arbitrary. For example, thermal insulation material can be used for the spacer 30. However, other functional materials may also be used for the spacer 30.

[0035] The spacer 30 shown here is attached to the second side surface 20. Figure 2 illustrates a single spacer 30 on the upper side of the second side surface 20, in which the dimension along the longer side is larger than the dimension along the shorter side (in other words, a shape that extends along the longer side). However, the spacer 30 may be attached to the first side surface 10, or to any location or area on the side surfaces 10 and 20 as long as it does not interfere with the terminals 12 and 21, and there may be more than one spacer 30.

[0036] For example, if a spacer 30 is provided in a portion of the area on the sides 10 and 20 where terminals 12 and 21 are not provided, a gap will be formed in the space between the single cells 2A and 2B, where nothing is provided except in the area where the positive terminal 21 and the spacer 30 are located. The form of the spacer 30 described above is not limited to the form in which it is attached to the second side surface 20 and extends in the direction of the long side, as described above. For example, instead of the spacer 30 extending in the direction of the long side, as shown in Figure 4, the spacer 30 may not be attached to the second side surface 20, and a spacer 30 attached to the first side surface 10 may be used, as shown in Figure 5. The spacer 30 illustrated in Figure 5 extends in the direction of the short side. Thus, a form of spacer 30 may be adopted in which, when viewed in the direction of alignment, the dimension in the direction along the short side of the first side surface 10 or the second side surface 20 is larger than the dimension along the long side (in other words, a form that extends in the direction of the short side).

[0037] In Figure 5, the spacers 30 are shown as a pair, spaced apart in the width direction. However, the spacers 30 arranged along the short side are not limited to one; three or more may be arranged side by side, spaced apart in the width direction. Furthermore, spacers 30 may be provided on both the first side surface 10 and the second side surface 20. Alternatively, if spacers 30 are provided in the entire area on the sides 10 and 20 where terminals 12 and 21 are not provided, the space between the single cells 2A and 2B will be filled with the positive terminal 21 and spacers 30 (no empty gaps will be formed).

[0038] [1-2.Second form] As shown in Figure 7, the second form of the battery pack 1A is provided with a convex terminal 13 as the negative terminal 11. The convex terminal 13 protrudes from the first side surface 10. This convex terminal 13 is in contact with the positive terminal 21', and the convex terminal 13 and the positive terminal 21' are electrically connected in series.

[0039] In the battery pack 1A shown in Figure 7, the first single cell 2A has a convex terminal 13 positioned on the upper part of the first side surface 10 and a positive terminal 21' positioned on the lower part of the second side surface 20. Similarly, the second single cell 2B has a convex terminal 13 positioned on the lower part of the first side surface 10 and a positive terminal 21' positioned on the upper part of the second side surface 20. The battery pack 1A is constructed by arranging the first single cell 2A and the second single cell 2B, which have different arrangements of terminals 13 and 21', alternately.

[0040] The terminals 13 and 21' described above are provided in a tapered shape that narrows towards the convex tip. Specifically, the convex terminal 13 is formed in a tapered shape that narrows towards the first direction, and the positive terminal 21' is formed in a tapered shape that narrows towards the second direction. The cross-sectional shape of these terminals 13 and 21' along the vertical and width directions may be a polygonal frustum, or the cross-sectional shape along the vertical and width directions may be an elliptical or circular frustum.

[0041] As illustrated in Figure 7, the tip 14 of the convex terminal 13 has a recess 15 into which the tip 22' of the positive terminal 21' can be inserted and removed. That is, the convex terminal 13 is not only a protrusion from the second side surface 20, but also has a recess 15 at its tip 14. The tip 22' of the positive terminal 21' is not recessed. With the tip 22' of the positive terminal 21' inserted into this recess 15, the convex terminal 13 and the positive terminal 21' are electrically connected in series. The recess 15 described above is provided in an inverse taper shape corresponding to the taper shape formed at the tip 22' of the positive terminal 21'.

[0042] Here, the dimension to which the positive terminal 21' protrudes from the second side surface 20 is defined as the "first protrusion dimension L1'". Also, the dimension obtained by subtracting the "recess dimension L3'", the dimension to which the recess 15 is recessed at the tip 14 of the protrusion terminal 13 is formed (L2'-L3'), from the "second protrusion dimension L2'", the dimension to which the protrusion terminal 13 protrudes from the first side surface 10 is defined as the "actual second protrusion dimension L23'". The actual second protrusion dimension L23' can also be said to be the dimension to which the protrusion terminal 13 substantially protrudes. Note that the second protrusion dimension L2' is set to be larger than the recess dimension L3'. Furthermore, the dimension to which the first side surface 10 and the second side surface 20 are separated in the direction of alignment is defined as the "separation dimension L4'".

[0043] The above-mentioned first convex dimension L1', actual second convex dimension L23', and separation dimension L4' satisfy the equation "L1' + L23' = L4'", where the sum of the first convex dimension L1' and the actual second convex dimension L23' equals the separation dimension L4'. In other words, the protrusion of the positive terminal 21' and the effective protrusion of the convex terminal 13 work together to prevent adjacent cell units 2A and 2B from being placed close together with a separation dimension shorter than L4'. In this way, the close placement of cell units 2A and 2B is structurally restricted by terminals 13 and 21'.

[0044] However, the tip portion 14 of the convex terminal 13 does not necessarily have a recess 15. In this case, the sum of the first convex dimension L1' and the second convex dimension L2' is equal to the separation dimension L4' (i.e., the equation "L1' + L2' = L4'" is satisfied). The battery pack 1A illustrated in the second embodiment is provided with two types of spacers 30': a first spacer 31' and a second spacer 32'. The first spacer 31' is attached to the first side surface 10. The second spacer 32' is attached to the second side surface 20.

[0045] As shown in Figure 8, the first spacer 31' and the second spacer 32' are provided to be able to fit together. Figure 8 illustrates a columnar first spacer 31' and a cylindrical second spacer 32'. The second spacer 32' has a space extending through it in the direction of the first spacer 31', the size of which corresponds to the volume of the first spacer 31'. When the first spacer 31' is inserted into the space extending through the second spacer 32', the spacers 31' and 32' fit together. When the first spacer 31' is removed from the space extending through the second spacer 32', the fit between the spacers 31' and 32' is released.

[0046] Figure 8 illustrates a first spacer 31' whose cross-sectional shape along the vertical and width directions is elliptical. The cross-sectional shape of the first spacer 31' along the vertical and width directions is preferably a shape other than a perfect circle, such as an ellipse or polygon. In other words, the cross-sectional shape of the space that penetrates the second spacer 32' along the vertical and width directions is preferably a shape other than a perfect circle. However, the cross-sectional shape of the first spacer 31' along the vertical and width directions is not limited to an ellipse and may be any shape. However, it is preferable that the cross-sectional shapes and arrangement of the spacers 31' and 32' along the vertical and width directions are set in order to prevent relative rotation about the axis of rotation along the direction of alignment.

[0047] The arrangement of terminals 13, 21' and spacer 30' in single cells 2A and 2B will be explained below with reference to Figures 9 and 10. For illustrative purposes, terminals 13 and 21' are shown as circles and spacer 30' as a square in Figures 9 and 10. The terminals 13, 21' and spacer 30' explained here are not extended like terminals 12 and 21 in the first form, but are arranged partially (so to speak, as points).

[0048] The convex terminal 13 of the first cell 2A is located on the lower and third-direction side (right side in Figure 9) of the first side surface 10, as shown by the solid line in Figure 9. The positive terminal 21' of the first cell 2A is located on the upper and fourth-direction side (left side in Figure 9) of the second side surface 20, as shown by the dashed line in Figure 9. In other words, the first cell 2A has terminals 13 and 21' located on the diagonal corners of the first side surface 10 and the second side surface 20, respectively (lower right and upper left in Figure 9) when viewed in the direction of alignment.

[0049] Furthermore, the first spacer 31' of the first cell 2A is located on the upper and fourth-direction side of the first side surface 10, as shown by the solid line in Figure 9. The second spacer 32' of the first cell 2A is located on the lower and third-direction side of the second side surface 20, as shown by the dashed line in Figure 9. In other words, the first cell 2A has spacers 31' and 32' located on the diagonal corners of the first side surface 10 and the second side surface 20, respectively, when viewed in a parallel direction.

[0050] The convex terminal 13 of the second cell 2B is located on the upper and fourth-direction side (left side in Figure 10) of the first side surface 10, as shown by the solid line in Figure 10. The positive terminal 21' of the second cell 2B is located on the lower and third-direction side (right side in Figure 10) of the second side surface 20, as shown by the dashed line in Figure 10. In other words, the second cell 2B has terminals 13 and 21' located on the diagonal corners of the first side surface 10 and the second side surface 20, respectively (upper left and lower right in Figure 10) when viewed in the direction of alignment.

[0051] Furthermore, the first spacer 31' of the second cell 2B is located on the lower and third-direction side of the first side surface 10, as shown by the solid line in Figure 10. The second spacer 32' of the second cell 2B is located on the upper and fourth-direction side of the second side surface 20, as shown by the dashed line in Figure 10. In other words, the second cell 2B has spacers 31' and 32' located on the diagonal corners of the first side surface 10 and the second side surface 20, respectively, when viewed in parallel.

[0052] [1-3. Third form] As shown in Figure 11, the third form of the battery pack 1B is provided with two negative terminals 11 and two positive terminals 21'', and does not have spacers 30, 30′ (see Figures 6 and 7). The negative terminal 11 is provided as a pair of first recessed terminals 12A and second recessed terminals 12B. The positive terminal 21″ is provided as a pair of first positive terminal 21A″ and second positive terminal 21B″.

[0053] The dimensions of the recessed or convex terminals 12A, 12B and positive terminals 21A″, 21B″ are the same as the dimensions L1, L2, L3 described above in the first form. Also, the positive terminals 21A″, 21B″ are provided in a tapered shape that narrows towards the convex tip, similar to the positive terminal 21 in the first form. The recessed terminals 12A, 12B are provided in an inverse tapered shape that corresponds to the tapered shape of the positive terminals 21A″, 21B″, similar to the recessed terminal 12 in the first form.

[0054] The recessed terminals 12A, 12B and the positive terminals 21A″, 21B″ shown here all extend along the short sides of the sides 10 and 20. The first recessed terminal 12A is positioned on the third direction side (left side in Figure 11) of the first side surface 10. On the other hand, the second recessed terminal 12B is positioned on the fourth direction side (right side in Figure 11) of the first side surface 10. In other words, the first side surface 10 is provided with a pair of recessed terminals 12A and 12B arranged in the width direction.

[0055] Furthermore, the first positive terminal 21A'' is positioned on the third direction side of the second side surface 20. On the other hand, the second positive terminal 21B'' is positioned on the upper fourth direction side of the second side surface 20. In other words, the second side surface 20 is provided with a pair of positive terminals 21A'' and 21B'' arranged in the width direction.

[0056] Furthermore, the extension direction of the recessed terminals 12A, 12B and the positive terminals 21A″, 21B″ is not limited to the direction along the short side of the side surfaces 10, 20, but may also be along the long side, or any other direction along the extension plane of the side surfaces 10, 20. The configuration in which the recessed terminals 12A, 12B and the positive terminals 21A'', 21B'' extend along the long sides of the sides 10, 20 can also be described as a configuration in which the second recessed terminal 12B and the second positive terminal 21B'' are provided in place of the spacer 30 of the first configuration.

[0057] [2. Action and Effects] Since the battery packs 1, 1A, and 1B of this embodiment are configured as described above, the following functions and effects can be obtained. (1) In the battery packs 1, 1A, and 1B of this embodiment, the negative terminal 11 and the positive terminals 21, 21', and 21'' are electrically connected in series with the first side surface 10 and the second side surface 20 separated. That is, the first side surface 10 and the second side surface 20 can be separated simply by connecting the individual cells 2 in series in the battery packs 1, 1A, and 1B. Therefore, even if one individual cell 2 in the battery packs 1, 1A, and 1B overheats, it is possible to suppress the chain reaction of temperature increases in other individual cells 2 caused by that heat. Thus, the protective performance of the battery packs 1, 1A, and 1B can be enhanced. Furthermore, since components such as busbars connecting the negative terminal 11 and the positive terminals 21, 21', and 21'' can be omitted, it contributes to simplifying the configuration of batteries using battery packs 1, 1A, and 1B.

[0058] (2) In the second form of the battery pack 1A, a convex terminal 13 protruding from the first side surface 10 is provided as the negative terminal 11, and both the convex terminal 13 and the positive terminal 21' are protruding and butted together in a series connection. With this type of battery pack 1A, compared to the first form of the battery pack 1 where a recessed terminal 12 recessed from the first side surface 10 is provided as the negative terminal 11, internal space for the single cell 2 can be secured. Therefore, this contributes to increasing the freedom of layout and the amount of capacity of the components housed inside the single cell 2.

[0059] (3) In a configuration in which the tip portion 14 of the convex terminal 13 does not have a recess 15, the relative positions of the convex terminal 13 and the positive terminal 21' are not restricted, and there is a risk that the two single cells 2 cannot be stably connected in series. In contrast, in the second form of the battery pack 1A, a recess 15 is provided at the tip 14 of the convex terminal 13, into which the tip 22' of the positive terminal 21' can be inserted and removed. With the tip 22' of the positive terminal 21' inserted into the recess 15, the convex terminal 13 and the positive terminal 21' are electrically connected in series. Therefore, with the tip 22' of the positive terminal 21' inserted into the recess 15, the relative positions of the convex terminal 13 and the positive terminal 21' are restricted, allowing for a stable series connection of the two individual cells.

[0060] (4) In the first form of the battery pack 1, the dimension obtained by subtracting the recess dimension L2 of the recessed terminal 12 relative to the first side surface 10 from the convex dimension L1 of the positive terminal 21 relative to the second side surface 20 is equal to the separation dimension L3 between the first side surface 10 and the second side surface 20. That is, by setting the dimensions such that the convex dimension L1 of the positive terminal 21 is longer than the recess dimension L2 of the recessed terminal 12, the first side surface 10 and the second side surface 20 are separated when the recessed terminal 12 and the positive terminal 21 are electrically connected in series. In this way, the first side surface 10 and the second side surface 20 can be separated simply by setting the relative dimensions of the convex dimension L1 and the recess dimension L2. Furthermore, since the recessed terminal 12 and the positive terminal 21 are electrically connected in series with the tip 22 of the positive terminal 21 inserted into the recessed terminal 12, the relative positions of the recessed terminal 12 and the positive terminal 21 are restricted, allowing for a stable series connection of the two single cells.

[0061] (5) The positive terminals 21, 21', and 21'' are provided in a tapered shape that narrows towards the convex tip, thus ensuring greater strength at the base end compared to terminals with a tapered shape that narrows towards the base end. The positive terminals 21, 21″ of the first and third forms are inserted into recessed terminals 12, 12A, 12B, which are provided in a reverse taper shape. Therefore, two adjacent single cells 2A, 2B can be electrically connected in series simply by bringing them close together along the direction of alignment (first and second directions). For example, this improves the ease of connecting single cells 2A, 2B compared to a battery pack structure where single cells are electrically connected by sliding them in a direction perpendicular to the direction of alignment.

[0062] (6) In the first form of the battery pack 1, the recessed terminal 12 extends in the direction along the long side of the first side surface 10, and the positive terminal 21 extends in the direction along the long side of the second side surface 20. With terminals 12 and 21 extending along the long side in this way, a greater extension dimension of terminals 12 and 21 can be secured compared to the case where the terminals extend along the short side. In other words, longer terminals 12 and 21 can be provided on the single cell 2. Therefore, for example, displacement such as the single cell 2 rotating around a rotation axis along the direction of alignment can be suppressed, and conductivity can be improved by securing the contact area between terminals 12 and 21.

[0063] (7) In the first and second forms of the battery pack 1,1A, in addition to the negative terminal 11 and positive terminals 21,21' which are connected in series with the first side surface 10 and the second side surface 20 spaced apart, spacers 30,30' are provided interposed between the first side surface 10 and the second side surface 20. This ensures that the first side surface 10 and the second side surface 20 are securely separated. This also enhances the protective capabilities of the battery pack 1,1A.

[0064] On the other hand, in the third form of battery pack 1B, although spacers 30 and 30' are not provided, a pair of first recessed terminals 12A and second recessed terminals 12B are provided as negative terminals 11, and a pair of first positive terminals 21A'' and second positive terminals 21B'' are provided as positive terminals 21''. Therefore, one of the pair of negative terminals 11 and one of the pair of positive terminals 21'' perform the same function as spacers 30 and 30', ensuring that the first side surface 10 and the second side surface 20 are reliably separated. In addition, conductivity can be improved by ensuring the contact area between terminals 12 and 21''.

[0065] (8) In the first form of the battery pack 1, as illustrated in Figure 5, if the spacer 30 is provided in a shape in which the dimension along the short side is larger than the dimension along the long side of the first side surface 10 or the second side surface 20, and extends in the direction of the short side, then the spacer 30 that is long in the direction of the long side and extends in the direction of the long side, as illustrated in Figure 2 of the first form of the battery pack 1, is not provided. Here, if we compare the spacer 30 that extends in the direction of the short side as illustrated in Figure 5 and the spacer 30 that extends in the direction of the long side as illustrated in Figure 2, assuming that they are both strips of a certain width and the same number are used, the spacer 30 that extends in the direction of the short side can reduce the contact area with the first side surface 10 and the second side surface 20 more than the spacer 30 that extends in the direction of the long side. By reducing the contact area between the sides 10, 20 and the spacer 30 in this way, it is possible to secure a gap between the first side surface 10 and the second side surface 20 in which neither the spacer 30 nor the terminals 12, 21 are provided. Therefore, heat dissipation can be improved. From this perspective as well, the protective capabilities of battery pack 1 can be enhanced.

[0066] (9) The second form of the battery pack 1A is provided with a first spacer 31' attached to the first side surface 10 and a second spacer 32' attached to the second side surface 20 that can be fitted together. As a result, the first spacer 31' and the second spacer 32' can be fitted together, thereby suppressing misalignment between the individual cells 2.

[0067] (10) Furthermore, the spacers 31' and 32', which are arranged diagonally on the first side surface 10 and the second side surface 20 when viewed in the direction of alignment, make it easier to position the individual cells 2 together and further suppress misalignment between the individual cells 2.

[0068] (11) When thermal insulation material is used as spacers 30, 30', the thermal insulation material will be interposed between the first side surface 10 and the second side surface 20. In this case, even if one cell 2 in the battery pack 1, 1A overheats, the transfer of heat from this overheating cell 2 to other adjacent cells can be further suppressed. Therefore, the protective performance of the battery pack 1, 1A can be further enhanced.

[0069] [II. Variant Examples] The embodiments described above are merely examples of various possible specific embodiments. For example, Figure 1 of the above-described embodiment shows a battery pack 1 in which the first side surface 10 facing the first direction and the second side surface 20 facing the second direction are substantially parallel, but it is not necessary for the first side surface 10 and the second side surface 20 to be strictly parallel. The cross-sectional shape of the single cell 2 shown in Figure 1 may be, for example, trapezoidal, triangular, polygonal, etc., and is not limited to a rectangular shape.

[0070] The battery packs 1, 1A, and 1B of this embodiment only need to include positive terminals 21, 21', and 21'' that are electrically connected in series with the negative terminal 11, with at least the first side surface 10 and the second side surface 20 spaced apart in the direction of alignment. The sides 10 and 20 on which terminals 11, 21, 21', and 21'' are provided can be set to any side of the case 4 of the single cell 2, as long as they face in opposite directions to each other. In one embodiment, at least two of the above-described first, second, and third forms may be combined. For example, the negative terminal 11 may include both the concave terminal 12 of the first form and the convex terminal 13 of the second form. Furthermore, the positive terminals 21, 21', and 21'' provided on the first side surface 10 may be interpreted as negative terminals, and the negative terminal 11 provided on the second side surface 20 may be interpreted as a positive terminal. [Explanation of Symbols]

[0071] 1,1A,1B assembled battery 2, 2A, 2B single cell 10 First aspect 11 Negative terminal (first terminal) 12 Recessed terminal 13 Convex terminal 14 Tip 15 recesses 20 Second aspect 21,21′,21″ Positive terminal (second terminal) 22,22′ Tip 30,30′ Spacer 31′ First Spacer 32' Second Spacer L1 convex dimension L2 concave dimension L3 Separation Dimension

Claims

1. A battery pack in which a plurality of single cells, each having a first side facing a predetermined first direction and a second side facing a second direction opposite to the first direction, are arranged side by side with their first and second sides facing each other, Each of the aforementioned plurality of single cells, A first terminal provided on the first side surface, The system includes a second terminal that protrudes from the second side surface and is electrically connected in series with the first terminal, with the first side surface facing the second side surface spaced apart from the second side surface in the second direction. A battery pack characterized by the following features.

2. The first terminal has a protruding terminal that protrudes from the first side surface. The battery pack according to claim 1, characterized in that

3. The tip of the convex terminal has a recess into which the tip of the second terminal is inserted and removed, and the convex terminal and the second terminal are electrically connected in series when the tip is inserted into the recess. The battery pack according to claim 2, characterized in that

4. The first terminal has a recessed terminal formed in the first side surface, and the tip of the second terminal is provided to be insertable and removable, and the recessed terminal and the second terminal are electrically connected in series when the tip is inserted into the recessed terminal. The dimension obtained by subtracting the recessed dimension of the concave terminal (relative to the first side surface) from the convex dimension (protruding dimension of the second terminal relative to the second side surface) is equal to the distance between the first side surface and the second side surface. The battery pack according to claim 1, characterized in that

5. The second terminal is provided in a tapered shape that narrows towards the protruding tip, The recessed terminal is provided in an inverse taper shape corresponding to the taper shape. The battery pack according to claim 4, characterized in that

6. The first side and the second side are each rectangular in shape, surrounded by a pair of long sides and a pair of short sides. The first terminal and the second terminal are provided extending in the direction along the long side. The battery pack according to claim 1, characterized in that

7. The spacer is attached to at least one of the first side and the second side and is interposed between the first side and the second side. A battery pack according to any one of claims 1 to 6, characterized in that

8. The first side and the second side are each rectangular in shape, surrounded by a pair of long sides and a pair of short sides. The spacer is formed such that, when viewed from the first or second direction, the dimension in the direction along the shorter side is larger than the dimension in the direction along the longer side. The battery pack according to claim 7, characterized in that it is a battery pack according to claim 7.

9. The spacer comprises a first spacer attached to the first side surface and a second spacer attached to the second side surface, and the first spacer and the second spacer are provided to be able to fit together. The battery pack according to claim 7, characterized in that it is a battery pack according to claim 7.

10. The first side and the second side are each rectangular in shape. The spacers are positioned diagonally on each of the first and second sides. The battery pack according to claim 7, characterized in that it is a battery pack according to claim 7.

11. The aforementioned spacer includes an insulating material. The battery pack according to claim 7, characterized in that it is a battery pack according to claim 7.

Images