Battery pack

Abstract

To provide a battery pack in which peeling of an insulating film from a housing is suppressed.SOLUTION: The insulating film provided on the outer surface of each of the plurality of batteries includes a joint portion on the outer surface, an adhesive layer bonding the outer surface and the restraint member is formed, the adhesive layer has an island-shaped portion, and the island-shaped portion is formed such that a length in a third direction orthogonal to a first direction (an arrangement direction of the plurality of batteries) and a second direction (a direction in which the plurality of batteries and the restraint member face each other) changes in the first direction, the length (A) in the third direction of the island-shaped portion in the joint portion of the insulating film and the maximum value (B) of the length in the third direction of the island-shaped portion satisfy the relationship of A <B * 0.9.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] A battery pack has been known in the past in which a plurality of batteries are arranged and restrained in the stacking direction using a restraining member. Furthermore, the battery housing has traditionally been covered with an insulating film. An example of such a battery is the one described in International Publication No. 2016 / 035395 (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 035395 Summary of the Invention [Problem to be solved by the invention]

[0004] When a battery pack is constructed, the insulating film may be bonded to a restraining member for vibration protection or other reasons. When the restraining member deforms, a force may act through the adhesive layer in a direction that peels the insulating film from the battery casing. From the perspective of preventing peeling of the insulating film, there is still room for improvement in conventional battery packs.

[0005] An object of the present technology is to provide a battery pack in which peeling of an insulating film from a housing is suppressed. [Means for solving the problem]

[0006] The present technology provides the following assembled battery.

[0007] [1] A battery includes a plurality of batteries, each of which includes a housing for accommodating an electrode body, arranged in a first direction, and a restraining member for restraining the plurality of batteries in the first direction, the restraining member facing the plurality of batteries in a second direction perpendicular to the first direction, each of the plurality of batteries including an outer surface facing the restraining member in the second direction, an insulating film provided on the outer surface, the insulating film including a seam portion on the outer surface, an adhesive layer for bonding the outer surface and the restraining member formed, the adhesive layer having island-shaped portions, the island-shaped portions being formed such that their lengths in a third direction perpendicular to the first direction and the second direction vary in the first direction, and a length (A) of the island-shaped portions in the third direction at the seam portion of the insulating film and a maximum length (B) of the island-shaped portions in the third direction are A <B×0.9 A battery pack that satisfies the above relationship.

[0008] [2] The battery pack according to [1], wherein the adhesive layer is not formed at the joint portion of the insulating film. [Effects of the Invention]

[0009] According to the present technology, it is possible to provide a battery pack in which peeling of the insulating film from the housing is suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing a battery pack. [Figure 2] FIG. 2 is a perspective view of a battery constituting a battery pack. [Figure 3] FIG. 10 is a diagram showing the state in the middle of covering the battery casing with an insulating film. [Figure 4] FIG. 10 is a diagram showing a state in which the battery casing is covered with an insulating film. [Figure 5] FIG. 5 is a view of the state shown in FIG. 4 as seen from the X-axis direction. [Figure 6] FIG. 10 is a diagram showing an adhesive layer provided between the battery housing and the restraining member. [Figure 7] FIG. 1 is a diagram (part 1) showing an example of the arrangement of adhesive layers. [Figure 8] FIG. 2 is a diagram (part 2) showing an example of the arrangement of adhesive layers. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0012] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0013] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0014] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0015] In this specification, the term "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the term "electrode" may collectively refer to a positive electrode and a negative electrode.

[0016] The "battery" in this specification can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), etc. However, the use of the "battery" is not limited to in-vehicle use.

[0017] Fig. 1 is a perspective view of a battery module according to the present embodiment. As shown in Fig. 1, the battery pack 1 includes batteries 100 and separators 200. The batteries 100 and the separators 200 are arranged alternately along the Y-axis direction (first direction).

[0018] The batteries 100 are rectangular batteries, and a plurality of batteries 100 are provided along the Y-axis direction. The plurality of batteries 100 are electrically connected to each other via bus bars (not shown).

[0019] The separators 200 are provided between the multiple batteries 100. The separators 200 are insulating members that prevent unintended electrical conduction between adjacent batteries 100. The separators 200 ensure electrical insulation between adjacent batteries 100. The separators 200 may also be provided between the batteries 100 and end plates (not shown).

[0020] 2 is a perspective view showing the battery 100. As shown in FIG. 2, the battery 100 has a rectangular shape. The battery 100 has an electrode terminal 110, a housing 120, and a gas release valve .

[0021] The electrode terminal 110 is formed on the housing 120. The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112 that are aligned along an X-axis direction (second direction) that is perpendicular to a Y-axis direction (first direction). The positive electrode terminal 111 and the negative electrode terminal 112 are spaced apart from each other in the X-axis direction.

[0022] The housing 120 has a rectangular parallelepiped shape and forms the external appearance of the battery 100. The housing 120 includes a case body 120A that houses an electrode assembly and an electrolyte (not shown), and a sealing plate 120B that seals the opening of the case body 120A. The sealing plate 120B is joined to the case body 120A by welding.

[0023] The housing 120 has an upper surface 121, a lower surface 122, a first side surface 123, a second side surface 124, and two third side surfaces 125.

[0024] The upper surface 121 is a plane perpendicular to the Z-axis direction (third direction) that is perpendicular to the Y-axis direction and the X-axis direction. The electrode terminals 110 are disposed on the upper surface 121. The lower surface 122 faces the upper surface 121 along the Z-axis direction.

[0025] Each of the first side surface 123 and the second side surface 124 is made of a plane perpendicular to the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the housing 120. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction, with the X-axis direction being the longitudinal direction and the Z-axis direction being the lateral direction.

[0026] The multiple batteries 100 are stacked such that the first side surfaces 123 and the second side surfaces 124 of the batteries 100 adjacent to each other in the Y-axis direction face each other. As a result, the positive electrode terminals 111 and the negative electrode terminals 112 are arranged alternately in the Y-axis direction in which the multiple batteries 100 are stacked.

[0027] Gas release valve 130 is provided on top surface 121. When the temperature of battery 100 rises (thermal runaway) and the internal pressure of housing 120 exceeds a predetermined value due to gas generated inside housing 120, gas release valve 130 releases the gas to the outside of housing 120.

[0028] Next, the insulating film 300 provided on the housing 120 of the battery 100 will be described with reference to FIGS.

[0029] 3 to 5, the insulating film 300 is provided to cover the first side surface 123, the second side surface 124, and two third side surfaces 125 of the housing 120. By providing the insulating film 300, the insulation properties of each of the batteries 100 incorporated in the battery pack 1 are improved.

[0030] 3 (insulating film 300 in the middle of being covered), first portion 301 and second portion 302 of insulating film 300 are folded and overlapped on third side surface 125. As a result, insulating film 300 includes seam portion 310 on third side surface 125, as shown in FIGS. 4 and 5 (insulating film 300 covered state).

[0031] Next, the force acting on the insulating film will be described with reference to FIG. 6. As shown in FIG. 6, in the battery pack 1, the plurality of batteries 100 are restrained in the Y-axis direction by restraining members 500.

[0032] The restraining member 500 faces the casing 120 of the battery 100 in the X-axis direction. A third side surface 125 (outer surface) of the casing 120 faces the restraining member 500. An adhesive layer 400 is provided between the third side surface 125 and the restraining member 500. The adhesive layer 400 bonds the third side surface 125 and the restraining member 500. By providing the adhesive layer 400, the vibration resistance of the battery pack 1 can be improved.

[0033] When the assembled battery 1 vibrates, a force acts to peel off the insulating film 300 on the housing 120 via the adhesive layer 400 as the restraining member deforms (arrow in Fig. 6). If peeling of the insulating film 300 occurs, the insulation of the battery 100 may deteriorate. This technology focuses on achieving both improved vibration resistance of the assembled battery 1 and improved insulation of the battery 100, and provides a preferred arrangement of the adhesive layer 400 for suppressing peeling of the insulating film 300 even when vibration occurs in the assembled battery 1.

[0034] Figs. 7 and 8 are diagrams showing preferred arrangement examples of the adhesive layer 400 based on the above viewpoints. In the examples of Figs. 7 and 8, a substantially elliptical island-shaped portion (adhesive layer 400) is shown, but the shape of the island-shaped portion may be an irregular shape including fine irregularities.

[0035] As shown in Figs. 7 and 8, when viewed from the X-axis direction, the adhesive layer 400 has an island-shaped portion. The island-shaped portion is formed such that the length in the Z-axis direction changes in the Y-axis direction.

[0036] In the example of Fig. 7, the length (A) in the Z-axis direction of the island-shaped portion at the seam portion 310 of the insulating film 300 and the maximum value (B) of the length in the Z-axis direction of the island-shaped portion satisfy the relationship of A < B × 0.9 (preferably, A < B × 0.8, more preferably, A < B × 0.7, still more preferably A < B × 0.5).

[0037] In the example of Fig. 8, the adhesive layer 400 is not formed at the seam portion 310 of the insulating film 300. That is, at the seam portion 310, A = 0.

[0038] 7 and 8, the length of the island-shaped portion in the Z-axis direction is not uniform in the Y-axis direction, and the length (A) of the insulating film 300 in the Z-axis direction at the seam 310 is relatively small. Therefore, when vibration is applied to the battery pack 1 and the restraining member 500 is deformed, the force (the force that peels the insulating film 300) transmitted via the adhesive layer 400 to the seam 310, which is relatively prone to peeling, can be reduced. As a result, it is possible to provide a battery pack 1 in which peeling of the insulating film 300 from the casing 120 of the battery 100 is suppressed.

[0039] 7 and 8 do not necessarily hold for all of the batteries 100 in the battery pack 1. It is sufficient that the length (A) in the Z-axis direction of the seam portion 310 is relatively small in a portion of the batteries 100 in the battery pack 1 (for example, about one-third or more, preferably about half or more).

[0040] Also, as shown in Figure 7, the island-shaped portions of the adhesive layer 400 may be individually separated, or adjacent island-shaped portions may be connected by the adhesive layer 400 as long as the relationship between the Z-axis length of the island-shaped portions described above is satisfied.

[0041] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0042] 1 battery pack, 100 battery, 110 electrode terminal, 111 positive electrode terminal, 112 negative electrode terminal, 120 housing, 120A case body, 120B sealing plate, 121 upper surface, 122 lower surface, 123 first side surface, 124 second side surface, 125 third side surface, 130 gas release valve, 200 separator, 300 insulating film, 301 first portion, 302 second portion, 310 joint portion, 400 adhesive layer, 500 restraining member.

Claims

1. a plurality of batteries arranged in a first direction, each battery including a housing that houses an electrode assembly; a restraining member that restrains the plurality of batteries in the first direction, the restraint member faces the plurality of batteries in a second direction perpendicular to the first direction; each of the plurality of batteries includes an outer surface facing the restraining member in the second direction; an insulating film is provided on the outer surface, the insulating film including a seam portion on the outer surface; an adhesive layer is formed to bond the outer surface and the restraint member; the adhesive layer has an island-shaped portion, and the island-shaped portion is formed so that a length in a third direction perpendicular to the first direction and the second direction varies in the first direction; The length (A) of the island-shaped portion in the third direction at the seam portion of the insulating film and the maximum length (B) of the island-shaped portion in the third direction are A < B x 0.9 A battery pack that satisfies the above relationship.

2. The battery pack according to claim 1 , wherein the adhesive layer is not formed at the joint portion of the insulating film.

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