Battery pack

Abstract

To provide a battery pack that can suppress displacement of the battery module in the event of an impact. [Solution] The battery pack of the present invention comprises a case, a plurality of battery modules stacked and housed in the case, metal components stacked alternately with the battery modules and housed in the case, and a filler material filled in the case to fix the battery modules and metal components in the case, wherein the filler material is a foamed material, and through holes are provided at the ends of the metal components that penetrate in the stacking direction between the battery modules and the metal components, and the filler material is filled into the through holes.

Description

Technical Field

[0001] The present invention relates to a battery pack.

Background Art

[0002] Patent Document 1 discloses a filling method of filling a foaming material between battery cells.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a battery pack in which a case in which a plurality of battery modules are stacked and housed is filled with a filler made of a foaming member having low rigidity, for example, when the battery pack is impacted from the horizontal direction, the position of the battery module may be greatly displaced.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack capable of suppressing displacement of the battery module when impacted.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the battery pack according to the present invention comprises a case, a plurality of battery modules stacked and housed in the case, metal components stacked alternately with the battery modules and housed in the case, and a filler material filled in the case to fix the battery modules and the metal components in the case, wherein the filler material is a foamed material, and through holes are provided at the ends of the metal components that penetrate in the stacking direction between the battery modules and the metal components, and the filler material is filled in the through holes.

[0007] As a result, in the battery pack according to the present invention, a filler made of foamed material can be filled into through holes provided at the ends of metal parts, and the metal parts can be hooked and fixed with the filler, thereby preventing the position of the battery module, which is fixed together with the metal parts by the filler, from shifting when subjected to impact.

[0008] Furthermore, in the above, the metal part may be a cooler, a conductive plate, or a current collector plate.

[0009] This allows for the use of components commonly found in battery packs, thus preventing an increase in the number of components and a larger battery pack size. [Effects of the Invention]

[0010] The battery pack according to the present invention has the effect of suppressing displacement of the battery module when subjected to impact. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a top view showing a schematic configuration of a battery pack according to an embodiment. [Figure 2] Figure 2 is a cross-sectional view of the battery pack shown in Figure 1. [Figure 3] Figure 3(a) is a top view showing an example of a metal part. Figure 3(b) is a side view showing an example of a metal part. [Figure 4] Figure 4 is an enlarged view of a through-hole made in a metal part. [Modes for carrying out the invention]

[0012] The following describes an embodiment of the battery pack according to the present invention. However, the present invention is not limited to this embodiment.

[0013] Figure 1 is a top view showing the schematic configuration of a battery pack 1 according to an embodiment. Figure 2 is a cross-sectional view of the battery pack 1 shown in Figure 1. The battery pack 1 according to the embodiment is mounted on an electric vehicle and is a power supply source that supplies power to a motor, which is the drive source of the electric vehicle. The battery pack 1 according to the embodiment includes a case 2 composed of an upper case (not shown) and a lower case. The battery pack 1 according to the embodiment also includes a plurality of battery modules 3 stacked in the stacking direction shown in Figure 2 and housed in the case 2, metal parts 4 stacked alternately with the battery modules 3 via adhesive members or the like and housed in the case 2, and a filler material 5 that fills the case 2 and fixes the battery modules 3 and metal parts 4 inside the case 2. In the battery pack 1 according to the embodiment, the stacking direction of the battery modules 3 and metal parts 4 corresponds to the height direction of the battery pack 1, and the direction perpendicular to the stacking direction (height direction) is the horizontal direction.

[0014] The battery module 3 is configured in a plate shape by housing a bipolar electrode body inside an outer casing made of laminate film, for example. The battery module 3 may also be configured in a plate shape by housing a monopolar electrode body inside an outer casing, or by arranging rectangular battery cells in a row. Furthermore, the number of battery modules 3 housed in the case 2 in the battery pack 1 according to this embodiment is not limited to two as shown in Figure 2; for example, two or more battery modules 3 can be provided.

[0015] The metal component 4 is, for example, a cooler, a current-carrying plate, or a current-collecting plate. The cooler is a component that is placed between stacked battery modules 3 via an adhesive member or the like to cool the battery modules 3. The current-carrying plate is a component that is placed between stacked battery modules 3 via an adhesive member or the like to electrically connect adjacent battery modules 3. The current-collecting plate is a component that functions as the positive or negative electrode of a plurality of battery modules 3 that are electrically connected in series. Note that the number of metal components 4 housed in the case 2 in the battery pack 1 according to this embodiment is not limited to one as shown in Figure 2, but for example, one or more metal components 4 can be provided.

[0016] The filler material 5 is filled into the case 2 to bond the battery module 3 and metal parts 4 together and fix them inside the case 2. The filler material 5 is a foamed material that foams and hardens when two liquids are mixed, for example, a main component containing isocyanate and a curing agent containing polyether polyol.

[0017] Figure 3(a) is a top view showing an example of a metal part 4. Figure 3(b) is a side view showing an example of a metal part 4. In the battery pack 1 according to this embodiment, as shown in Figures 3(a) and 3(b), the metal part 4 has a main body portion 41 with a thickness t1 and a peripheral portion 42 with a thickness t2 that surrounds the main body portion 41. The thickness t2 of the peripheral portion 42 is smaller than the thickness t1 of the main body portion 41, and the peripheral portion 42 is located in the central part of the main body portion 41 in the thickness direction. Note that in Figures 3(a) and 3(b), the main body portion 41 and the peripheral portion 42 are illustrated with rough shapes for the sake of simplicity of explanation. Therefore, the thickness t1 of the main body portion 41 and the thickness t2 of the peripheral portion 42 are, for example, the average thickness of the main body portion 41 and the peripheral portion 42, respectively.

[0018] A plurality of through-holes 40 penetrating the peripheral portion 42 in the stacking direction (thickness direction) are provided in the peripheral portion 42 which is the end portion of the metal part 4. The through-hole 40 has, for example, an elongated hole shape having two arc portions 401 spaced apart from each other in the longitudinal direction and a straight portion 402 connecting the two arc portions 401 in the longitudinal direction. Note that the shape of the through-hole 40 is not limited to the elongated hole shape, and may be, for example, a circular shape or a square shape. The through-hole 40 is filled with a filler 5 from the gap between the battery module 3 and the peripheral portion 42 of the metal part 4.

[0019] FIG. 4 is an enlarged view of the through-hole 40 provided in the metal part 4. As shown in FIG. 4, the diameter A of the arc portion 401 in the through-hole 40 is set such that A ≧ 6 [mm]. Also, the length B of the straight portion 402 in the through-hole 40 is set such that B ≧ 12 [mm]. Further, for adjacent through-holes 40, the longitudinal interval C between the connection portion 403 between the arc portion 401 and the straight portion 402 in one through-hole 40 and the connection portion 403 between the arc portion 401 and the straight portion 402 in the other through-hole 40 is set such that C ≦ 70 [mm]. Note that when each dimension A, B, C of the through-hole 40 having an elongated hole shape is outside the above range, for example, when the battery pack 1 is subjected to an impact from the horizontal direction, the filler 5 that has entered the through-hole 40 may crack, making it difficult to prevent the position of the metal part 4 and thus the battery module 3 from shifting.

[0020] Also, the thickness t2 of the peripheral portion 42 of the metal part 4 is preferably set such that 0.5 [mm] ≦ t2 ≦ 2.4 [mm]. When the thickness t2 of the peripheral portion 42 is less than 0.5 [mm], the peripheral portion 42 may be deformed by the pressure when filling the filler 5. Also, when the thickness t2 of the peripheral portion 42 is greater than 2.4 [mm], the gap (closing portion) between the battery module 3 and the peripheral portion 42 becomes too narrow, and there is a risk that the filler 5 will not be filled in the gap (closing portion) or the through-hole 40.

[0021] In the battery pack 1 according to the embodiment, since the through hole 40 is filled with the filler 5, the peripheral portion 42 of the metal part 4 can be hooked and fixed by the filler 5, and the amount of displacement of the metal part 4 when receiving an impact from the horizontal direction can be reduced. Further, the amount of displacement of the battery module 3 fixed to the metal part 4 by the filler 5 can also be reduced when receiving an impact from the horizontal direction, and the battery module 3 can be protected from the impact. In particular, when the battery module 3 is composed of a bipolar electrode body, electrode foils and the like of the bipolar electrode body can be protected from the impact.

[0022] Here, in order to prevent the battery module 3 from moving even when the battery pack 1 receives an impact from the horizontal direction, if a high-rigidity reinforcing member is to be provided between the case 2 and the battery module 3, a large space for providing the reinforcing member is required. Therefore, it becomes difficult to secure a high capacity by mounting the battery module 3 on the case 2 with the maximum size.

[0023] On the other hand, in the battery pack 1 according to the embodiment, the through hole 40 provided in the peripheral portion 42 which is the end portion of the metal part 4 is filled with the filler 5 made of a foaming member, and the metal part 4 can be hooked and fixed by the filler 5. Thereby, when the battery pack 1 receives an impact from the horizontal direction, even with the filler 5 made of a foaming member having low rigidity without providing a high-rigidity reinforcing member, the position of the battery module 3 fixed together with the metal part 4 by the filler 5 and the adhesive member or the like can be suppressed from shifting. Therefore, the battery pack 1 according to the embodiment does not need to secure a space for providing a high-rigidity reinforcing member in the case 2, and thus can mount the battery module 3 on the case 2 with the maximum size to secure a high capacity. Further, in the battery pack 1 according to the embodiment, since the metal part 4 is a cooler, a conductive plate, or a current collector plate, generally used parts provided in the battery pack 1 are used, so that an increase in the number of parts and an increase in the size of the battery pack 1 can be suppressed.

Explanation of Reference Numerals

[0024] 1 Battery pack 2 cases 3 Battery Module 4 Metal parts 5 Filling material 40 Through holes 41 Main body 42 Peripheral area 401 Arc section 402 Straight section 403 Connection section

Claims

1. The case and Multiple battery modules stacked and housed within the case, Metal components are stacked alternately with the aforementioned battery modules and housed within the case, A filling material is provided inside the case to secure the battery module and the metal components within the case. A battery pack equipped with, The aforementioned filler is a foamed material, The end of the metal component is provided with a through hole that penetrates in the stacking direction between the battery module and the metal component. A battery pack characterized in that the through-hole is filled with the filler material.

2. The battery pack according to claim 1, characterized in that the metal component is a current-carrying plate that electrically connects the battery modules, a cooler that cools the battery modules, or a current-collecting plate that functions as an electrode for a plurality of electrically connected battery modules.

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