battery pack

Abstract

A battery pack is provided that has high heat insulating effect and durability due to insulating members provided between a plurality of batteries. [Solution] An insulating member arranged between multiple batteries includes a plate-shaped main body made of insulating material and a film covering the main body, and the film has a fixed portion at the end in a second direction perpendicular to the first direction that is folded over and fixed in an overlapping state.

Description

[Technical Field]

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

[0002] In a battery pack in which a plurality of batteries are arranged, an insulating member has conventionally been disposed between the plurality of batteries. An example of a conventional battery pack is the one described in International Publication No. 2018 / 061894 (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 061894 Summary of the Invention [Problem to be solved by the invention]

[0004] By disposing insulating members, it is necessary to improve the heat insulating effect between adjacent batteries. It is also necessary to improve the durability of the insulating members. From the viewpoint of improving the heat insulating effect and durability of the insulating members, 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 insulating members provided between a plurality of batteries have high heat insulating effect and durability. [Means for solving the problem]

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

[0007] [1] A battery pack comprising a plurality of batteries arranged in a first direction and an insulating member provided between the plurality of batteries, the insulating member including a plate-shaped main body made of a heat insulating material and a film covering the main body, the film having a fixed portion at an end in a second direction perpendicular to the first direction that is folded back and fixed in a stacked state.

[0008] [2] The battery pack according to [1], wherein the main body of the insulating member is formed relatively thin at a portion facing the fixed portion of the film.

[0009] [3] The battery pack according to [1] or [2], wherein the fixed portion has a dimension of 3 mm or more and 15 mm or less in the second direction.

[0010] [4] The battery pack described in any one of [1] to [3], wherein each of the plurality of batteries includes a housing that houses an electrode body, and the fixing portion has a dimension in the second direction that is 0.006 to 0.3 times the dimension of the housing of the battery.

[0011] [5] The battery pack described in any one of [1] to [4], wherein each of the plurality of batteries includes a housing that houses an electrode body, and the insulating member is provided over the entire housing of the battery in the second direction.

[0012] [6] The battery pack described in any one of [1] to [5], wherein the insulating member is configured as a separate member from the member consisting of the main body and the film, and further includes an elastic body laminated in the first direction, the elastic body including a base portion and a pressing portion, and when viewed from the first direction, the pressing portion is arranged to avoid the fixed portion of the film. [Effects of the Invention]

[0013] According to the present technology, it is possible to provide a battery pack having high heat insulating effect and durability due to insulating members provided between a plurality of batteries. [Brief explanation of the drawings]

[0014] [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] 1 is a diagram showing a configuration of an insulating member (separator) according to a first embodiment. FIG. [Figure 4] FIG. 10 is a diagram showing the configuration of an insulating member (separator) according to a second embodiment. [Figure 5] FIG. 2 is a diagram showing a first step in the manufacturing process of the insulating member (separator). [Figure 6] FIG. 10 is a diagram showing a second step in the manufacturing process of the insulating member (separator). [Figure 7] FIG. 10 is a diagram showing a third step in the manufacturing process of the insulating member (separator). [Figure 8] FIG. 10 is a diagram illustrating the range of the folded-back portion of the film. [Figure 9] FIG. 2 is a schematic diagram of a side view of a wound electrode body. DETAILED DESCRIPTION OF THE INVENTION

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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).

[0019] 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.

[0020] 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.

[0021] 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 separators 200 are arranged alternately along the Y-axis direction (first direction). The arranged batteries 100 and separators 200 are restrained and held in the Y-axis direction using restraining members (bind bars and end plates) or a pack case (not shown).

[0022] 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).

[0023] 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).

[0024] 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 .

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] FIG. 3 is a diagram showing the configuration of a separator 200 (insulating member) according to one embodiment.

[0033] 3, separator 200 includes a plate-shaped main body 210 and a film 220 (laminate material) that covers main body 210. Film 220 includes a first film 221 that covers one surface of main body 210 and a second film 222 that covers the other surface of main body 210.

[0034] First film 221 and second film 222 are folded back at their ends in the X-axis direction and fixed in an overlapping state, thereby forming fixed portion 223 of film 220. Although not shown in Fig. 3, the ends in the Z-axis direction may have a configuration similar to fixed portion 223 shown in Fig. 3.

[0035] Furthermore, film 220 may be made up of one film, or three or more films may be used. Furthermore, fixed portion 223 shown in Fig. 3 is not limited to being formed at both ends in the X-axis or Z-axis direction, but may be formed at one end in the X-axis or Z-axis direction.

[0036] The main body 210 is made of a heat insulating material. Examples of heat insulating materials include glass wool, rock wool, cellulose fiber, and aerogel. Alternatively, a mixed molding material of an inorganic filler and a binder, or a solidified mixture of inorganic fiber and inorganic powder may be used.

[0037] Examples of materials that can be used to form film 220 include PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), and PVC (polyvinyl chloride).

[0038] 3, the main body 210 has a step portion 211. By providing the step portion 211, the main body 210 is formed relatively thin in the portion facing the fixed portion 223 of the film 220.

[0039] One of the functions of the separator 200 is to improve the heat insulating effect between adjacent cells 100 in the battery pack 1. From this perspective, it is preferable to form the main body 210 made of a heat insulating material to be large.

[0040] On the other hand, it is also necessary to improve the durability of the separator 200. From this perspective, it is preferable to cover the main body 210 with the film 220 and further increase the overlapping area at the joint of the film 220. By increasing the overlapping area, it is possible to increase the strength of the joint of the film 220 and suppress damage to the joint. As a result, the durability of the main body 210 is also improved.

[0041] However, increasing the overlapping area at the joint of the film 220 may cause interference with the surrounding members of the separator 200 (such as a restraining member that restrains the battery 100 in the Y-axis direction).

[0042] 3, the film 220 is folded back at a fixing portion 223 located at an end in the X-axis direction or the Z-axis direction and fixed in an overlapping state. This allows the overlapping area at the joint of the film 220 to be increased while avoiding interference with surrounding components, thereby improving the durability of the separator 200. Furthermore, the main body 210 made of a heat insulating material can be made large.

[0043] Thus, the separator 200 according to this embodiment can achieve both high heat insulating effect and high durability.

[0044] FIG. 4 is a diagram showing the configuration of a separator 200 (insulating member) according to another embodiment.

[0045] 4 is formed by laminating a member made up of a main body 210 and a film 220 with an elastic body 230 formed as a separate member. By providing the elastic body 230, it is possible to more easily absorb deformation (expansion) of the battery 100 in the Y-axis direction.

[0046] The elastic body 230 includes a base portion 231 and a pressing portion 232. The base portion 231 is preferably formed over the entire area of ​​the separator 200. This makes it easier to assemble the battery pack 1. The pressing portion 232 is formed only on the central side of the separator 200. The pressing portion 232 abuts against an adjacent battery 100. When the battery pack 1 is viewed from the Y-axis direction, the elastic body 230 is preferably positioned so that the pressing portion 232 and the fixed portion 223 of the film 220 do not overlap.

[0047] That is, when viewed from the Y-axis direction, it is preferable that pressing portion 232 of elastic body 230 is provided at a position that avoids fixed portion 223 of film 220 (a region that does not overlap with fixed portion 223), and fixed portion 223 of film 220 is provided at a position that avoids pressing portion 232 (a region that does not overlap with pressing portion 232). Note that when pressing portion 232 is made up of multiple protrusions, pressing portion 232 is a region formed by connecting the outer peripheral edges of multiple protrusions located at the outermost periphery.

[0048] 5 to 7, the manufacturing process of separator 200 will be described. First, as shown in Fig. 5, main body 210 is sandwiched between first film 221 and second film 222, and first film 221 and second film 222 are overlapped at the end of main body 210. The overlapped first film 221 and second film 222 are joined to each other by adhesive portion 224.

[0049] 6, the overlapping first film 221 and second film 222 are folded back and placed on top of main body 210. The folded back first film 221 and second film 222 are joined onto main body 210 by adhesive portion 225. This forms fixed portion 223.

[0050] Next, the portion where fixed portion 223 is formed (the portion where first film 221 and second film 222 are folded back and overlapped) is pressed in the Y-axis direction using jig 300. This results in separator 200 shown in FIG.

[0051] Next, a preferred range of fixed portion 223 will be described with reference to Figures 8 and 9. As shown in Figure 8, region 120Y where electrode body 140 abuts against the inner surface of casing 120 (in the case of a wound-type electrode body 140 as shown in Figure 9, the region of flat portion 141 excluding R portion 142), region 120X where pressing portion 232 of elastic body 230 is located, region 120V located inside fixed portion 223 (the portion where film 220 is overlapped), and region 120W on first side surface 123 and second side surface 124 of casing 120 preferably have a relationship in which region 120W encompasses region 120V, region 120V encompasses region 120X, and region 120X encompasses region 120Y.

[0052] The first side surface 123 and the second side surface 124 of the housing 120 preferably have dimensions (width or height) of approximately 50 mm or more and 500 mm or less in the X-axis or Z-axis direction. The fixed portion 223 preferably has dimensions (width or height) of approximately 3 mm or more and 15 mm or less in the X-axis or Z-axis direction. The fixed portion 223 preferably has dimensions (width or height) of 0.006 to 0.3 times the dimensions (width or height) of the housing 120 in the X-axis or Z-axis direction. The separator 200 is preferably provided over the entire housing 120 in the X-axis or Z-axis direction. However, the present technology is not limited to those having the above dimensional relationships.

[0053] 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]

[0054] 1 battery pack, 100 battery, 110 electrode terminal, 111 positive electrode terminal, 112 negative electrode terminal, 120 housing, 120A case body, 120B sealing plate, 120V, 120W, 120X, 120Y regions, 121 upper surface, 122 lower surface, 123 first side surface, 124 second side surface, 125 third side surface, 130 gas release valve, 140 electrode body, 141 flat portion, 142 R portion, 200 separator, 210 body, 211 stepped portion, 220 film, 221 first film, 222 second film, 223 fixed portion, 224, 225 adhesive portion, 230 elastic body, 231 base portion, 232 pressing portion.

Claims

1. a plurality of batteries arranged in a first direction; an insulating member provided between the plurality of batteries; the insulating member includes a plate-shaped main body made of a heat insulating material and a film covering the main body, The film has a fixed portion that is folded back and fixed in an overlapping state at an end portion in a second direction perpendicular to the first direction.

2. The battery pack according to claim 1 , wherein the main body of the insulating member is formed to be relatively thin at a portion facing the fixed portion of the film.

3. 3. The battery pack according to claim 1, wherein the fixed portion has a dimension of 3 mm or more and 15 mm or less in the second direction.

4. Each of the plurality of batteries includes a housing that houses an electrode assembly, 3. The battery pack according to claim 1, wherein the fixed portion has a dimension in the second direction that is 0.006 to 0.3 times the dimension of the casing of the battery.

5. Each of the plurality of batteries includes a housing that houses an electrode assembly, 3. The battery pack according to claim 1, wherein the insulating member is provided over the entire casing of the battery in the second direction.

6. the insulating member is configured as a separate member from the main body and the member made of the film, and further includes an elastic body laminated in the first direction; the elastic body includes a base portion and a pressing portion, 3. The battery pack according to claim 1, wherein the pressing portion is provided so as to avoid the fixed portion of the film when viewed from the first direction.

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