Battery pack

Abstract

This invention provides a battery pack capable of preventing adhesive spillage between a battery module formed by stacking multiple battery cells and a constraint member constraining the multiple battery cells, thus preventing contact between the adhesive and the terminals of the battery cells. A battery pack includes: a battery module formed by stacking multiple battery cells with terminals disposed on their upper surfaces in the thickness direction; a constraint member constraining the multiple battery cells in the thickness direction; an adhesive disposed between a side of the battery cell facing a direction orthogonal to the thickness direction when viewed from above and the constraint member; and an insulating member, at least a portion of which is disposed between the constraint member and the side of the battery cell on a side further upward than the adhesive.

Description

Technical Field

[0001] This invention relates to a battery pack. Background Technology

[0002] A known structure has the following configuration: a heat-absorbing component containing a heat-absorbing agent is provided between the battery module and the constraint band, the battery module being composed of alternately stacked battery cells and separators, and the constraint band constraining the battery module (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent No. 7054867 Summary of the Invention

[0004] When an adhesive is used between the battery module and the constraint band, it may overflow from the upper surface of the battery cell during assembly of the constraint band. Since terminals are located on the upper surface of the battery cell, if the overflowing adhesive comes into contact with the terminals of an adjacent battery cell, it can cause a short circuit.

[0005] Therefore, the object of the present invention is to obtain a battery pack that can prevent the adhesive disposed between the battery module formed by stacking multiple battery cells and the constraint member constraining the multiple battery cells from overflowing and contacting the terminals of the battery cells.

[0006] To achieve the above objectives, the battery pack according to the first aspect of the present invention comprises: a battery module consisting of a plurality of battery cells having terminals disposed on an upper surface stacked in the thickness direction; a restraining member restraining the plurality of battery cells in the thickness direction; an adhesive disposed between the side of the battery cell facing a direction orthogonal to the thickness direction when viewed from above and the restraining member; and an insulating member, at least a portion of which is disposed between the restraining member and the side of the battery cell on a side higher than the adhesive.

[0007] According to the invention of the first aspect, a battery module is constituted by a plurality of battery cells having terminals disposed on their upper surface and stacked in the thickness direction. The plurality of battery cells are constrained in the thickness direction by a constraining member, and an adhesive is placed between the side of each battery cell facing in a direction orthogonal to its thickness direction when viewed from above and the constraining member.

[0008] Here, at least a portion of the insulating component is located between the constraint component, which is positioned above the adhesive, and the side surface of each battery cell. Therefore, this insulating component prevents adhesive from overflowing from the upper surface of each battery cell. That is, it prevents adhesive, which is disposed between the battery module formed by stacking multiple battery cells and the constraint component constraining the multiple battery cells, from overflowing and contacting the terminals of the battery cells.

[0009] Furthermore, the battery pack of the second aspect of the present invention is the battery pack of the first aspect, and the insulating member is configured to press the battery cell downward.

[0010] According to the second embodiment of the invention, each battery cell is pressed to the lower side by an insulating member. Therefore, displacement of each battery cell due to external forces applied to the battery module is suppressed.

[0011] Furthermore, the battery pack of the third aspect of the present invention is the battery pack of the first or second aspect, wherein, when viewed from the thickness direction, the upper surface of the insulating member is an inclined surface that slopes outward and downward.

[0012] According to the third aspect of the invention, when viewed from the thickness direction of the battery cell, the upper surface of the insulating member is an inclined surface that slopes outward and downward. Therefore, this insulating member prevents water from entering the upper surface (terminal) of each battery cell.

[0013] Furthermore, the battery pack of the fourth aspect of the present invention is the battery pack of the first or second aspect, wherein, when viewed from the thickness direction, the upper surface of the insulating member is formed into a concave shape.

[0014] According to the fourth aspect of the invention, when viewed from the thickness direction of the battery cell, the upper surface of the insulating member is formed into a concave shape. Therefore, this insulating member prevents water from entering the upper surface (terminal) of each battery cell.

[0015] Invention Effects

[0016] As described above, according to the present invention, it is possible to prevent the adhesive disposed between the battery module formed by stacking multiple battery cells and the constraint member constraining the multiple battery cells from overflowing and contacting the terminals of the battery cells. Attached Figure Description

[0017] Figure 1 This is a schematic front view of the battery pack according to the first embodiment, viewed from the thickness direction of the battery cells.

[0018] Figure 2 This is a schematic front view of the battery pack according to the second embodiment, viewed from the thickness direction of the battery cells.

[0019] Figure 3 This is a schematic front view of the battery pack according to the third embodiment, viewed from the thickness direction of the battery cells.

[0020] Figure 4 This is a schematic front view of the battery pack involved in the comparative example, viewed from the thickness direction of the battery cells. Detailed Implementation

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. For ease of explanation, arrow UP, appropriately shown in each figure, will be interpreted as the upward direction of the battery pack, and arrow RH as the rightward direction of the battery pack. Therefore, in the following description, unless otherwise specified, the directions "up / down" and "left / right" refer to the vertical and horizontal directions within the battery pack. Furthermore, the thickness direction of the battery cells will be interpreted as the front / back direction of the battery pack, and this will be considered as a frontal view when viewed from this front / back direction; however, these directions are not particularly limited.

[0022] <First Embodiment>

[0023] First, the first embodiment will be described. Figure 1 As shown, the battery pack 10 according to the first embodiment includes: a battery module 12, which is formed by stacking a plurality of battery cells 14 in its thickness direction; and a constraint band 18, which serves as a constraint member for constraining the plurality of battery cells 14 in the thickness direction.

[0024] Positive and negative terminals are respectively provided on the left and right ends of the upper surface 14U of each battery cell 14 (towards the inner side in the left-right direction than the pressing part 24 of the cover 20 described later). Hereinafter, "terminal 15" will not be distinguished between positive and negative. Furthermore, insulating films 16 are attached to the side surface 14S and lower surface 14D of each battery cell 14 in the left-right direction (the direction orthogonal to the thickness direction when viewed from above).

[0025] The constraint band 18 is made of a metal such as aluminum and is mounted on the outer periphery of the battery module 12 in a manner that allows it to press and constrain each battery cell 14 in its thickness direction. Furthermore, an upper protrusion 18U and a lower protrusion 18D are integrally formed at the upper and lower ends of the constraint band 18, respectively, extending slightly toward the upper surface 14U and lower surface 14D (inward in the left-right direction) of each battery cell 14.

[0026] The adhesive G is disposed between the side surface 14S (specifically the film 16, but hereinafter referred to as "side surface 14S") of each battery cell 14 and the inner surface of the restraining band 18. The adhesive G is applied to the side surface 14S of each battery cell 14 except for the upper end 14A. Furthermore, at least a portion of the cover 20 (the insertion portion 26 described later), which is an insulating member extending along the thickness direction (front-back direction) of the battery cell 14, is disposed between the inner surface of the restraining band 18, which is located above the adhesive G, and the side surface 14S of each battery cell 14.

[0027] The cover 20 is made of materials such as mica, and has high insulation and heat resistance. Furthermore, the cover 20 has: a fitting portion 22 that is roughly inverted "U" shaped when viewed from the front, which fits into the upper end of the upper protrusion 18U including the restraint band 18; a pressing portion 24 that is roughly "V" shaped when viewed from the front, which extends integrally from the inner end of the fitting portion 22 in the left-right direction and downwards in the left-right direction, and presses the upper surface 14U of each battery cell 14 downwards; and an insertion portion 26 that is roughly inverted "L" shaped when viewed from the front, which bends at roughly right angles from the inner end of the fitting portion 22 in the left-right direction and then bends at roughly right angles downwards and extends integrally.

[0028] The width of the fitting portion 22 along the left-right direction of its lower surface is configured to be approximately the same as the width of the upper end portion of the upper protrusion 18U including the restraint band 18 along the left-right direction. The fitting portion 22 is fitted into the upper end portion including the upper protrusion 18U from the upper side and is thus installed (fixed). The pressing portion 24 is configured to contact the upper surface 14U of each battery cell 14 in a state of elastic deformation towards the upper side, and press the upper surface 14U of each battery cell 14 towards the lower side by its elastic restoring force.

[0029] When viewed from the front, the lower end portion 26D of the insertion portion 26 is generally curved inward in the left-right direction. Therefore, the insertion portion 26 is configured such that when it is inserted between the inner surface of the restraint band 18 and the upper end portion 14A of the side surface 14S of each battery cell 14, the outer surface of its upper side (the side of the curved portion 26U, excluding the lower end portion 26D) contacts the inner surface of the restraint band 18 from the lower surface of the upper protrusion portion 18U, and its lower end portion 26D is inserted in a state of elastic deformation outward in the left-right direction.

[0030] That is, the lower end portion 26D of the insertion portion 26 is configured to press the side surfaces 14S of each battery cell 14 inward in the left-right direction by its elastic restoring force (the inner surface of the lower end portion 26D contacts the side surfaces 14S of each battery cell 14 with a predetermined pressure). Thus, the insertion portion 26 of the cover 20 is configured to be located between the inner surface of the constraint band 18, which is located above the adhesive G, and the side surfaces 14S of each battery cell 14.

[0031] In addition, such as Figure 1 As shown, the lower end portion 26D of the insertion portion 26 can enter the interior of the adhesive G; although not shown in the figure, it may not enter the interior of the adhesive G. The insertion portion 26 with the cover 20 can be said to be located between the inner surface of the constraint band 18 (which is higher than the adhesive G) and the side surface 14S of each battery cell 14, provided that its upper side (the side of the curved portion 26U) is in contact with the inner surface of the constraint band 18 (which is higher than the adhesive G).

[0032] The function of the battery pack 10 according to the first embodiment configured as described above will be explained next.

[0033] First of all, Figure 4 The comparative example shown will be described using a battery pack 100. This battery pack 100 does not have a cover 20. Therefore, as... Figure 4 As shown, when the constraint band 18 is assembled to the outer periphery of the battery module 12, the adhesive G may overflow from the upper surface 14U of the battery cell 14 and come into contact with the terminal 15. That is, the adhesive G overflowing from the upper surface 14U of the battery cell 14 may come into contact with the terminal 15 of the adjacent battery cell 14 and cause a short circuit.

[0034] In contrast, the battery pack 10 according to the first embodiment is provided with a cover 20. That is, the insertion portion 26 of the cover 20 is located between the inner surface of the constraint band 18 which is located above the adhesive G and the side surface 14S of each battery cell 14 (which may include the upper end portion 14A that is not coated with adhesive G).

[0035] Therefore, the insertion portion 26 of the cover 20 can ensure the insulation distance between the restraint strap 18 and the side 14S of each battery cell 14, and can suppress or prevent the adhesive G from overflowing from the upper surface 14U of each battery cell 14.

[0036] That is, it can suppress or prevent the adhesive G provided between the battery module 12, which is formed by stacking multiple battery cells 14, and the constraint band 18 that constrains the multiple battery cells 14, from overflowing and contacting the terminals 15 of adjacent battery cells 14, thereby suppressing or preventing short circuits.

[0037] Furthermore, the cover 20 presses the upper surface 14U of each battery cell 14 downwards by the elastic restoring force of the pressing part 24, and presses the side surface 14S of each battery cell 14 inwards in the left-right direction by the elastic restoring force of the insertion part 26 (lower end 26D). Therefore, the cover 20 can suppress or prevent displacement of each battery cell 14 due to external forces applied to the battery module 12.

[0038] Furthermore, the cover 20 is made of materials such as mica, which not only has high insulation but also high heat resistance. Therefore, it can suppress or prevent the upper end of the restraint band 18 from melting due to the high-temperature gas generated during thermal runaway of the battery cell 14. That is, it can suppress or prevent the upper end of the molten restraint band 18 from contacting the terminal 15 of the adjacent battery cell 14 and short-circuiting.

[0039] <Second Implementation>

[0040] Next, the second embodiment will be described. Furthermore, the same symbols will be used to mark the same parts as in the first embodiment described above, and detailed descriptions (including common functions) will be omitted as appropriate.

[0041] like Figure 2 As shown, in this second embodiment, the shape of the fitting portion 22 in the cover 20 is different from that in the first embodiment. That is, when viewed from the thickness direction (front-back direction) of the battery cell 14, the upper surface 22U of the fitting portion 22 is an inclined surface that slopes downward and outward in the left-right direction.

[0042] Therefore, the upper surface 22U (inclined surface) of the fitting portion 22 in the cover 20 can suppress or prevent water W from entering the upper surface 14U (terminal 15) of each battery cell 14. That is, in the battery module 12, it is possible to suppress or prevent water W from entering the upper surface 14U (terminal 15) of each battery cell 14 and causing a short circuit.

[0043] <Third Implementation>

[0044] Finally, the third embodiment will be described. Furthermore, the same symbols will be used to mark the same parts as in the first embodiment described above, and detailed descriptions (including common functions) will be omitted where appropriate.

[0045] like Figure 3 As shown, in this third embodiment, the shape of the fitting portion 22 in the cover 20 is different from that in the first embodiment described above. That is, when viewed from the thickness direction (front-back direction) of the battery cell 14, the upper surface 22U of the fitting portion 22 is formed into a concave shape. In other words, a recess 22A extending along the thickness direction of the battery cell 14 is formed at the center of the fitting portion 22 in the width direction.

[0046] Therefore, the recess 22A of the fitting portion 22 in the cover 20 can suppress or prevent water from entering the upper surface 14U (terminal 15) of each battery cell 14. That is, in the battery module 12, it is possible to suppress or prevent water from entering the upper surface 14U (terminal 15) of each battery cell 14 and causing a short circuit.

[0047] The battery pack 10 according to this embodiment has been described above with reference to the accompanying drawings. However, the battery pack 10 according to this embodiment is not limited to the drawings, and appropriate design changes can be made without departing from the spirit of the present invention. For example, the third embodiment can be applied to the second embodiment. That is, a recess 22A can be formed on the upper surface 22U of the fitting portion 22, which is an inclined surface.

[0048] Symbol Explanation

[0049] 10-Battery pack, 12-Battery module, 14-Battery cell, 14S-Side, 14U-Top surface, 15-Terminal, 18-Constraint strap (constraint component), 20-Cover (insulating component), 26-Insert part (part), G-Adhesive.

Claims

1. A battery pack, characterized in that, have: A battery module is composed of multiple battery cells with terminals stacked on the upper surface in the thickness direction; A constraint component that constrains a plurality of the battery cells in the thickness direction; An adhesive, which is disposed between the side of the battery cell facing a direction orthogonal to the thickness direction when viewed from above and the restraining member; and An insulating component, at least a portion of which is located between the restraining component and the side surface of the battery cell, on a side higher than the adhesive.

2. The battery pack according to claim 1, characterized in that, The insulating component is configured to press the battery cell downwards.

3. The battery pack according to claim 1 or 2, characterized in that, When viewed from the thickness direction, the upper surface of the insulating component is an inclined surface that slopes outward and downward.

4. The battery pack according to claim 1 or 2, characterized in that, When viewed from the thickness direction, the upper surface of the insulating component is formed into a concave shape.

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