Battery pack

Abstract

The invention relates to a battery pack. An insulating member (200) provided between a plurality of cells (100) includes a plate-shaped main body (210) made of a heat insulating material, and a film (220) covering the main body (210), and the film (220) has a fixed portion (223) folded back at an end portion in a second direction orthogonal to a first direction and fixed in an overlapping state.

Description

Technical Field

[0001] This technology relates to battery packs. Background Technology

[0002] Conventionally, in battery packs consisting of multiple cells arranged together, insulating components are placed between the cells. An example of an existing battery pack is the one described in International Publication No. 2018 / 061894.

[0003] The requirement is to improve the thermal insulation between adjacent batteries by configuring insulating components. Additionally, there is a need to improve the durability of these insulating components. From the perspective of improving the thermal insulation and durability of the insulating components, there is still room for improvement in existing battery packs. Summary of the Invention

[0004] The purpose of this technology is to provide a battery pack with good thermal insulation and high durability by using insulating components placed between multiple batteries.

[0005] This technology provides the following battery packs. [1]

[0007] A battery pack includes: a plurality of batteries arranged along a first direction; and an insulating member disposed between the plurality of batteries, the insulating member comprising a plate-shaped body made of a heat-insulating material and a film covering the body, the film having a fixing portion formed by folding back at an end in a second direction orthogonal to the first direction and fixing it in an overlapping state. [2]

[0009] In the battery pack described in [1], the main body of the insulating component is formed in a relatively thin manner at the portion opposite to the fixed portion of the membrane. [3]

[0011] In the battery pack described in [1] or [2], the aforementioned fixing part has a size of 3 mm or more and 15 mm or less in the aforementioned second direction. [4]

[0013] In any of the battery packs described in [1] to [3], each of the plurality of batteries includes a housing for housing the electrode body, and the fixed portion has a size in the second direction that is more than 0.006 times and less than 0.3 times the size of the housing of the battery. [5]

[0015] In any of the battery packs described in [1] to [4], each of the plurality of batteries includes a housing for housing the electrode body, and the insulating component is provided in the second direction in such a manner that it extends throughout the housing of the battery. [6]

[0017] In any of the battery packs described in [1] to [5], the insulating component further includes an elastomer configured as a component different from the component composed of the main body and the membrane, and stacked in the first direction. The elastomer includes a base and a pressing portion, which is provided in a manner that avoids the fixing portion of the membrane when viewed from the first direction.

[0018] The above and other objects, features, aspects and advantages of the invention will become clear from the accompanying drawings and the following detailed description relating to the invention. Attached Figure Description

[0019] Figure 1 This is a 3D diagram representing the battery pack.

[0020] Figure 2 It is a 3D diagram of the batteries that make up the battery pack.

[0021] Figure 3 This is a diagram showing the structure of the insulating component (diaphragm) involved in one of the embodiments.

[0022] Figure 4 This is a diagram showing the structure of the insulating component (diaphragm) involved in the second embodiment.

[0023] Figure 5 This diagram shows the first step in the manufacturing process of the insulating component (diaphragm).

[0024] Figure 6 This diagram shows the second step in the manufacturing process of the insulating component (diaphragm).

[0025] Figure 7 This diagram shows the third step in the manufacturing process of the insulating component (diaphragm).

[0026] Figure 8 This is a diagram used to illustrate the extent of the membrane's folded-back portion.

[0027] Figure 9 This is a schematic diagram of the side of a wound electrode. Detailed Implementation

[0028] The embodiments of this technology will be described below. Furthermore, sometimes the same or equivalent parts are labeled with the same reference numerals in the accompanying drawings, and their descriptions are not repeated.

[0029] Furthermore, in the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of this technology is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. Additionally, in the embodiments described below, each constituent element is not necessarily essential to this technology unless specifically stated otherwise. Furthermore, this technology is not limited to performing all the effects mentioned in this embodiment.

[0030] Furthermore, in this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a structure is included, other structures besides that structure may be included, or none may be included.

[0031] Furthermore, when using geometric terms and terms indicating positional or directional relationships, such as "parallel," "orthogonal," "45° oblique," "coaxial," and "along," these terms allow for some errors or variations. When using terms indicating relative positional relationships, such as "upper side" and "lower side," these terms are used to indicate relative positional relationships in one state, and the relative positional relationships can be reversed or rotated to any angle depending on the orientation of each mechanism (e.g., reversing the overall structure).

[0032] In this specification, "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 positive and negative electrodes may be collectively referred to as "electrodes".

[0033] The term "battery" in this manual can be used in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the application of the "battery" is not limited to vehicle use.

[0034] Figure 1 This is a perspective view of the battery module involved in this embodiment. Figure 1 As shown, the battery pack 1 includes a battery 100 and a separator 200. The batteries 100 and separator 200 are arranged alternately along the Y-axis direction (first direction). The batteries 100 and separator 200 are held in place by constraining them in the Y-axis direction using constraint components (straps and end plates, not shown) or the battery pack housing, etc.

[0035] The battery 100 is a square battery, and multiple batteries are arranged along the Y-axis. The multiple batteries 100 are electrically connected to each other via a busbar (not shown).

[0036] A separator 200 is disposed between multiple batteries 100. The separator 200 is an insulating component that prevents accidental electrical conduction between adjacent batteries 100. The separator 200 ensures electrical insulation between adjacent batteries 100. The separator 200 can also be disposed between a battery 100 and an end plate (not shown).

[0037] Figure 2 This is a 3D diagram representing battery 100. (Example) Figure 2 As shown, the battery 100 has a square shape. The battery 100 has electrode terminals 110, a housing 120, and an exhaust valve 130.

[0038] Electrode terminals 110 are formed on housing 120. Electrode terminals 110 have positive terminals 111 and negative terminals 112 arranged along an X-axis direction (second direction) orthogonal to the Y-axis direction (first direction). Positive terminals 111 and negative terminals 112 are arranged to be separated from each other in the X-axis direction.

[0039] The housing 120 has a cuboid shape, forming the appearance of the battery 100. The housing 120 includes a housing body 120A that houses electrodes (not shown) and electrolyte, and a sealing plate 120B that seals the opening of the housing body 120A. The sealing plate 120B is joined to the housing body 120A by welding.

[0040] 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.

[0041] The upper surface 121 is a plane orthogonal to the Z-axis direction (the third direction), which is orthogonal to both the Y-axis and X-axis directions. Electrode terminals 110 are disposed on the upper surface 121. The lower surface 122 is opposite to the upper surface 121 along the Z-axis direction.

[0042] Each side of the first side 123 and the second side 124 is formed by a plane orthogonal to the Y-axis direction. Each side of the first side 123 and the second side 124 has the largest area among the multiple sides of the housing 120. When viewed in the Y-axis direction, each side of the first side 123 and the second side 124 has a rectangular shape. When viewed in the Y-axis direction, each side of the first side 123 and the second side 124 has a rectangular shape with the X-axis direction as the longer side and the Z-axis direction as the shorter side.

[0043] Multiple batteries 100 are stacked in a manner where adjacent batteries 100, 100 are arranged with their first side 123 facing each other and their second side 124 facing each other. Thus, in the Y-axis direction in which the multiple batteries 100 are stacked, the positive terminal 111 and the negative terminal 112 are alternately arranged side by side.

[0044] An exhaust valve 130 is provided on the upper surface 121. When the temperature of the battery 100 rises (thermal runaway) and the internal pressure of the housing 120 exceeds a predetermined value due to the gas generated inside the housing 120, the exhaust valve 130 discharges the gas to the outside of the housing 120.

[0045] Figure 3 This is a diagram showing the structure of the diaphragm 200 (insulating component) according to one embodiment.

[0046] like Figure 3 As shown, the diaphragm 200 includes a plate-shaped body 210 and a membrane 220 (laminated material) covering the body 210. The membrane 220 includes a first membrane 221 covering one side of the body 210 and a second membrane 222 covering the other side of the body 210.

[0047] The first membrane 221 and the second membrane 222 are folded back at their ends in the X-axis direction and fixed in an overlapping state. This forms the fixed portion 223 of the membrane 220. Furthermore, although in Figure 3 Not shown in the figure, but it can also have the same shape at the end in the Z-axis direction. Figure 3 The fixed part 223 shown has the same structure.

[0048] Alternatively, membrane 220 can be composed of a single membrane, or it can use three or more membranes. Figure 3 The fixed portion 223 shown is not limited to being formed at both ends in the X-axis direction or the Z-axis direction, but may also be formed at one end in the X-axis direction or the Z-axis direction.

[0049] The main body 210 is made of thermal insulation material. Examples of thermal insulation materials include glass wool, asbestos, cellulose fibers, and aerogel. Alternatively, a mixture of inorganic fillers and binders, or a cured material of inorganic fibers and inorganic powders, can also be used.

[0050] Examples of raw materials that constitute membrane 220 include PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), and PVC (polyvinyl chloride).

[0051] exist Figure 3 In this example, the main body 210 has a stepped portion 211. By providing the stepped portion 211, the main body 210 is formed in a relatively thin manner at the portion opposite to the fixed portion 223 of the membrane 220.

[0052] As one function of the separator 200, it is necessary to improve the heat insulation effect between adjacent batteries 100 in the battery pack 1. From this point of view, it is preferable to form a larger body 210 made of heat insulation material.

[0053] On the other hand, it is also necessary to improve the durability of the diaphragm 200. From this point of view, it is preferable to cover the body 210 with the membrane 220 and expand the overlap area of ​​the joint of the membrane 220. By expanding the overlap area, the strength of the joint of the membrane 220 can be improved, thereby suppressing damage to the joint. As a result, the durability of the body 210 is also improved.

[0054] However, by expanding the overlapping area of ​​the joint of the membrane 220, interference may occur with the peripheral components of the separator 200 (such as the constraint components that constrain the battery 100 in the Y-axis direction).

[0055] exist Figure 3 In the diaphragm 200 shown, at the fixed portion 223 located at the end in the X-axis or Z-axis direction, the membrane 220 is folded back and fixed in an overlapping state. Therefore, interference with surrounding components can be avoided, and the overlapping area of ​​the joint of the membrane 220 can be increased, thereby improving the durability of the diaphragm 200. In addition, the main body 210 made of heat-insulating material can be formed to be larger.

[0056] Thus, the diaphragm 200 according to this embodiment can achieve both high heat insulation effect and high durability.

[0057] Figure 4 This is a diagram showing the structure of the diaphragm 200 (insulating component) according to other embodiments.

[0058] Figure 4 The diaphragm 200 shown is formed by laminating a component consisting of a main body 210 and a membrane 220 with an elastomer 230, which is a different component. By providing the elastomer 230, deformation (expansion) in the Y-axis direction of the battery 100 can be easily absorbed.

[0059] The elastomer 230 includes a base 231 and a pressing portion 232. The base 231 is preferably formed over the entire area of ​​the separator 200. This facilitates the assembly of 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 the adjacent battery 100. Preferably, when the battery pack 1 is viewed from the Y-axis direction, the elastomer 230 is arranged such that the pressing portion 232 does not overlap with the fixing portion 223 of the membrane 220.

[0060] That is, preferably, when viewed from the Y-axis direction, the pressing portion 232 of the elastomer 230 is positioned away from the fixing portion 223 of the membrane 220 (the area that does not overlap with the fixing portion 223), and the fixing portion 223 of the membrane 220 is positioned away from the pressing portion 232 (the area that does not overlap with the pressing portion 232). Furthermore, when the pressing portion 232 is composed of multiple protrusions, the pressing portion 232 becomes a region formed by connecting the edges of the outer periphery sides of the multiple protrusions located at the outermost periphery.

[0061] Next, use Figures 5-7 The manufacturing process of diaphragm 200 will be explained. First, as follows... Figure 5 As shown, the main body 210 is held by the first membrane 221 and the second membrane 222, and the first membrane 221 and the second membrane 222 are overlapped at the end of the main body 210. The overlapped first membrane 221 and second membrane 222 are joined together by the adhesive portion 224.

[0062] Next, as Figure 6 As shown, the overlapping first film 221 and second film 222 are folded back and overlapped onto the main body 210. The folded first film 221 and second film 222 are joined to the main body 210 by the adhesive portion 225. Thus, the fixed portion 223 is formed.

[0063] Next, the clamp 300 is used to press the portion where the fixing portion 223 is formed (the portion where the first membrane 221 and the second membrane 222 are folded back and overlapped) in the Y-axis direction. This allows for the obtaining of... Figure 3 The diaphragm 200 is shown.

[0064] Next, use Figure 8 and Figure 9 The preferred range of the fixed portion 223 will be explained. For example... Figure 8 As shown, the preferred region 120Y where the electrode body 140 abuts against the inner surface of the housing 120 (e.g.) Figure 9 As shown, in the case of a wound electrode body 140, the regions of the planar portion 141 (excluding the R portion 142), the region 120X where the pressing portion 232 of the elastic body 230 is located, the region 120V located inside the fixed portion 223 (the portion where the membrane 220 overlaps), and the regions 120W of the first side surface 123 and the second side surface 124 of the housing 120 have the following relationship: region 120W includes region 120V, region 120V includes region 120X, and region 120X includes region 120Y.

[0065] Preferably, the first side 123 and the second side 124 of the housing 120 have dimensions (width or height) of 50 mm or more and 500 mm or less in the X-axis or Z-axis direction. Preferably, the fixing portion 223 has dimensions (width or height) of 3 mm or more and 15 mm or less in the X-axis or Z-axis direction. Preferably, the fixing portion 223 has a dimension (width or height) that is 0.006 times or more and 0.3 times or less than the dimension (width or height) of the housing 120 in the X-axis or Z-axis direction. Preferably, the diaphragm 200 is provided in a manner that extends throughout the entire housing 120 in the X-axis or Z-axis direction. However, this technology is not limited to having the above-described dimensional relationships.

[0066] Embodiments of the present invention have been described, but it should be considered that the embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the invention is set forth in the claims and is intended to include all modifications of the same meaning and scope as the claims.

Claims

1. A battery pack, characterized in that, have: Multiple batteries, arranged along a first direction; and An insulating component is disposed between the plurality of batteries. The insulating component comprises a plate-shaped body made of heat-insulating material and a membrane covering the body. The membrane has a fixed portion formed by folding back at an end in a second direction orthogonal to the first direction and fixing it in an overlapping state.

2. The battery pack according to claim 1, characterized in that, The body of the insulating component is formed in a relatively thin manner at the portion opposite to the fixed portion of the membrane.

3. The battery pack according to claim 1 or 2, characterized in that, The fixing part has a dimension of more than 3 mm and less than 15 mm in the second direction.

4. The battery pack according to claim 1 or 2, characterized in that, Each of the plurality of batteries includes a housing for accommodating the electrode bodies. The fixing portion has a size that is more than 0.006 times and less than 0.3 times the size of the battery casing in the second direction.

5. The battery pack according to claim 1 or 2, characterized in that, Each of the plurality of batteries includes a housing for accommodating the electrode bodies. The insulating component is disposed in the second direction in a manner that extends throughout the entire casing of the battery.

6. The battery pack according to claim 1 or 2, characterized in that, The insulating component further includes an elastomer configured as a different component from the component formed by the body and the membrane, and is stacked in the first direction. The elastomer includes a base and a pressing portion. When viewed from the first direction, the pressing portion is positioned to avoid the fixing portion of the membrane.

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