Battery pack

Abstract

The utility model provides a battery pack, which is characterized in that an electrical storage device is accommodated in a shell consisting of a lower shell and an upper shell, the lower shell and the upper shell are opposite in a first direction, a filling part is filled between the lower shell and the electrical storage device in a second direction orthogonal to the first direction, and the filling part is filled between the lower shell and the electrical storage device in the second direction. A buffer member is provided between the filling member and the electricity storage device, and the Young's modulus of the buffer member is smaller than the Young's modulus of the filling member. As a result, it is possible to suppress breakage of the power storage device while restricting displacement of the power storage device.

Description

Technical Field

[0001] The present utility model relates to a battery pack. Background Art

[0002] A battery module (laminated body) having a side restricting portion that suppresses displacement of battery cells in the horizontal direction is disclosed in Patent Document 1.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-081820

[0004] Since the space between the battery module and the side wall is filled with the side restricting portion, movement of the battery module in the horizontal direction can be restricted. However, depending on the magnitude of the inertial force, the battery module may be damaged. Summary of the Utility Model

[0005] The present utility model is completed in view of the above technical problems, and provides a battery pack that can restrict displacement of a power storage device while suppressing damage to the power storage device.

[0006] To solve the above technical problems, the battery pack of the present utility model is a battery pack in which a power storage device is housed in a housing composed of a lower housing and an upper housing. Among them, the lower housing and the upper housing face each other in a first direction, and in a second direction orthogonal to the first direction, a filling member is filled between the lower housing and the power storage device, and a buffer member is provided between the filling member and the power storage device in the second direction. The Young's modulus of the buffer member is smaller than the Young's modulus of the filling member.

[0007] Thereby, the battery pack of the present utility model can restrict displacement of the power storage device while suppressing damage to the power storage device.

[0008] In addition, in the battery pack of the present utility model, it may also be configured that: the power storage device has a plurality of battery modules stacked in the first direction, and the buffer member is located at a position overlapping the battery module when viewed from the second direction.

[0009] Thereby, for the battery module that is a weak part against impact, the buffer member is arranged at a position overlapping it when viewed from the second direction, so that damage to the power storage device (battery module) can be better suppressed.

[0010] In addition, in the battery pack of the present utility model, it may also be configured that: the buffer member has a communication hole communicating with the remaining space in the housing.

[0011] Thereby, the ejecta from the power storage device can be better discharged to the remaining space in the housing through the communication hole of the buffer member.

[0012] In addition, in the battery pack of the present utility model, it can also be configured that each of the plurality of battery modules laminated in the first direction in the power storage device has a safety valve, and the buffer member is dissolved by the ejected matter ejected from the safety valve or penetrated by the pressure of the ejected matter.

[0013] Thereby, the buffer member is dissolved or penetrated by the ejected matter ejected from the safety valve of the battery module, and thus the buffer member can be used as a discharge path for the ejected matter.

[0014] The battery pack of the present utility model has the effect of being able to suppress the breakage of the power storage device while restricting the displacement of the power storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view showing a schematic configuration when the battery pack according to the first embodiment is viewed from above.

[0016] Figure 2 To show Figure 1 A view of the A-A cross-section of the battery pack shown.

[0017] Figure 3 It is a partial cross-sectional view showing a schematic configuration of the battery pack according to the second embodiment.

[0018] Figure 4 It is a partial cross-sectional view showing a schematic configuration of the battery pack according to the third embodiment.

[0019] Figure 5 It is a cross-sectional view showing a schematic configuration when the battery pack according to the fourth embodiment is viewed from above.

[0020] Figure 6 To show Figure 5 A view of the B-B cross-section of the battery pack shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] First, a first embodiment of the battery pack of the present utility model will be described. In addition, this embodiment is not a limitation of the present utility model.

[0022] Figure 1 It is a cross-sectional view showing a schematic configuration when the battery pack 1 according to the first embodiment is viewed from above. Figure 2 To show Figure 1 A view of the A-A cross-section of the battery pack shown.

[0023] In the first embodiment, the battery pack 1 is mounted on an electric vehicle and is, for example, a power supply source that supplies power to a motor serving as a drive source of the electric vehicle. The battery pack 1 according to the first embodiment includes a housing 3 composed of an upper housing 31 and a lower housing 32. A battery stack 2 serving as an electricity storage device is housed in the housing 3.

[0024] The battery stack 2 is a laminate formed by alternately stacking a plurality of battery modules 21a, 21b, 21c, 21d and a plurality of current-carrying members 22a, 22b, 22c vertically between a lower current-collecting member 23a and an upper current-collecting member 23b in the height direction, which is the first direction, of the battery pack 1. In the battery pack 1 according to the first embodiment, the height direction is the same as the stacking direction of the plurality of battery modules 21a, 21b, 21c, 21d.

[0025] The upper housing 31 and the lower housing 32 face each other in the above-described height direction. The upper housing 31 and the lower housing 32 each have a flange-shaped upper joint portion 310 and a lower joint portion 320 for mutual engagement at their respective peripheries. In the housing 3, the upper joint portion 310 and the lower joint portion 320 are engaged to form a housing joint portion 300. When viewed from the vehicle width direction, which is the second direction orthogonal to the above-described height direction, the lower joint portion 320 is located at a position overlapping the battery stack 2. In addition, the second direction orthogonal to the height direction, which is the first direction, is not limited to the above-described vehicle width direction and includes, for example, the vehicle longitudinal direction (refer to Figure 1 ) orthogonal to the above-described height direction and the above-described vehicle width direction. In addition, in the battery pack 1 according to the first embodiment, the first direction is set as the vertical direction and the second direction is set as the horizontal direction.

[0026] In the housing 3, a filling member 4 that can fill the gap between the battery stack 2 and the lower housing 32 without a gap is filled so as to surround the periphery of the battery stack 2. In addition, the filling member 4 fills up to a position closer to the upper housing 31 side than the lower joint portion 320 in the above-described height direction. The upper end surface 400 of the filling member 4 is located at substantially the same height as the upper end surface 200 of the battery stack 2 in the above-described height direction. In addition, in the battery pack 1 according to the first embodiment, the upper surface of the upper current-collecting member 23b forms the upper end surface 200 of the battery stack 2. The filling member 4 functions as a displacement restricting portion that restricts displacement of the battery stack 2 in the lateral direction (the above-described vehicle width direction and the above-described vehicle longitudinal direction). As the filling member 4, for example, a material that is initially liquid and solidifies over time can be used.

[0027] In addition, as Figure 1As shown, in the above-described second direction, plate-shaped buffer members 5A, 5B, 5C, and 5D are provided between the side surface of the battery stack 2 and the filling member 4. Specifically, a pair of buffer members 5A and 5B are provided in the vehicle width direction so as to face each other with the battery stack 2 interposed therebetween. The buffer members 5A and 5B are respectively arranged in contact with the side surface of the battery stack 2 in the vehicle width direction. The width of the buffer members 5A and 5B in the vehicle front-rear direction is shorter than the width of the battery stack 2. In addition, a pair of buffer members 5C and 5D are provided in the vehicle front-rear direction so as to face each other with the battery stack 2 interposed therebetween. The buffer members 5C and 5D are respectively arranged in contact with the side surface of the battery stack 2 in the vehicle front-rear direction. The width of the buffer members 5C and 5D in the vehicle width direction is shorter than the width of the battery stack 2. In the following description, when the buffer members 5A, 5B, 5C, and 5D are not particularly distinguished, they are simply referred to as buffer members. The buffer members are arranged at least at one position on the outer periphery (the above-described second direction) of the battery stack 2.

[0028] Next, Figure 2 The battery pack 1 according to the first embodiment will be described using the buffer member 5A as an example. In addition, as the above-described second direction, although there are differences such as the vehicle width direction and the vehicle front-rear direction, basically the other buffer members 5B, 5C, and 5D are the same as the buffer member 5A, so their descriptions are omitted.

[0029] As Figure 2 shown, the upper end surface 500 of the buffer member 5A is located at substantially the same height as the upper end surface 200 of the battery stack 2 and the upper end surface 400 of the filling member 4 in the height direction, and is exposed in the upper remaining space 33 formed between the battery stack 2 and the upper housing 31 in the housing 3.

[0030] In addition, the Young's modulus of the buffer member 5A is smaller than that of the filling member 4. Thus, for example, when the vehicle collides and the battery stack 2 attempts to slide in the above-described second direction (horizontal direction), while restricting the displacement of the battery stack 2 in the above-described second direction (horizontal direction) by the filling member 4, the buffer member 5A absorbs energy (inertial force), so that breakage of the battery stack 2 can be suppressed.

[0031] In addition, the buffer member 5A is located at a position overlapping the battery stack 2 when viewed from the above-described second direction (the vehicle width direction), and is in contact with all the battery modules 21a, 21b, 21c, and 21d of the battery stack 2. Thus, the buffer member 5A is arranged at a position overlapping the battery modules 21a, 21b, 21c, and 21d which are weak parts with respect to impact when viewed from the above-described second direction, so that breakage of the battery stack 2 (battery modules) can be better suppressed.

[0032] As the buffer member, it can be a material with air permeability itself, or a material that is dissolved by the heat of the ejected matter ejected from the safety valve of the battery module or penetrated by the pressure of the ejected matter. Thus, in the battery pack 1 according to the first embodiment, the buffer member can be used as a discharge path for the ejected matter (ejected gas) ejected from the safety valve of the battery module, and the ejected matter (ejected gas) is discharged to the upper remaining space 33 in the housing 3. Therefore, an excessive increase in the internal pressure of the battery module can be suppressed, and safety can be improved.

[0033] In addition, in the battery pack 1 according to the first embodiment, by providing the buffer member, the usage amount of the filling member 4 can be reduced, so that an increase in the temperature of the battery module caused by heat generation due to the curing of the filling member 4 can be suppressed. Thus, both the protection of the battery module and the shortening of the curing time of the filling member 4 can be achieved, and cost reduction and quality improvement can be realized.

[0034] Next, a second embodiment of the battery pack of the present invention will be described. In addition, in this embodiment, the description of the same components as those in the first embodiment will be appropriately omitted.

[0035] Figure 3 It is a partial cross-sectional view showing a schematic configuration of the battery pack 1 according to the second embodiment.

[0036] In the battery pack 1 according to the second embodiment, an opening 50a is formed on the upper end surface 500 of the buffer member 5A, and the buffer member 5A has a communication hole 50 communicating with the upper remaining space 33 in the housing 3 via the opening 50a. The communication hole 50 is formed inside the buffer member in such a manner that the ejected matter (ejected gas) ejected from the safety valves of the battery modules 21a, 21b, 21c, and 21d can pass through and be discharged from the opening 50a to the upper remaining space 33 in the housing 3.

[0037] Thus, in the battery pack 1 according to the second embodiment, the communication hole 50 of the buffer member can be used as a discharge path for the ejected matter (ejected gas) ejected from the safety valves of the battery modules 21a, 21b, 21c, and 21d, and the ejected matter (ejected gas) can be discharged to the upper remaining space 33 in the housing 3.

[0038] Next, a third embodiment of the battery pack of the present invention will be described. In addition, in this embodiment, the description of the same components as those in the first embodiment will be appropriately omitted.

[0039] Figure 4 It is a partial cross-sectional view showing a schematic configuration of the battery pack 1 according to the third embodiment.

[0040] As Figure 4As shown, in the battery pack 1 according to the third embodiment, a plate-shaped partition wall 6 is provided on the lower housing 32. The partition wall 6 is spaced apart from the battery stack 2 by a predetermined interval so as to surround the periphery of the battery stack 2, and extends upward from the bottom surface portion 321 of the lower housing 32 in the above-described height direction. The upper end surface 600 of the partition wall 6 protrudes toward the upper housing 31 side more than the lower joint portion 320 in the above-described height direction. In addition, in the battery pack 1 according to the third embodiment, it is configured that in the above-described height direction, the height of the upper end surface (apex) 600 of the partition wall 6 is higher than the height of the upper end surface (apex) 200 of the battery stack 2 by a distance d. In addition, in the battery pack 1 according to the third embodiment, the upper surface of the upper current collector member 23b forms the upper end surface 200 of the battery stack 2.

[0041] A filling member 4 that can fill the space between the partition wall 6 and the battery stack 2 without gaps is filled between the partition wall 6 and the battery stack 2. In addition, the filling member 4 is filled to a position on the upper housing 31 side in the above-described height direction relative to the lower joint portion 320. The upper end surface 400 of the filling member 4 is located at substantially the same height as the upper end surface 200 of the battery stack 2 in the above-described height direction.

[0042] The buffer member 5A has an L-shaped configuration in which the lower portion in the above-described height direction protrudes toward the partition wall 6 side in the above-described second direction (in the vehicle width direction in Figure 4 this case). The lower portion of the buffer member 5A extends into the through hole 60 provided in the lower portion of the partition wall 6. The upper end surface 500 of the buffer member 5A is covered by the filling member 4 in the above-described height direction and does not have an opening portion that opens into the upper remaining space 33 in the housing 3. On the other hand, an opening portion 50b is formed in the lower portion of the buffer member 5A, and the opening portion 50b opens into the side remaining space 34 formed between the partition wall 6 and the lower housing 32 in the vehicle width direction through the through hole 60 of the partition wall 6.

[0043] In the battery pack 1 according to the third embodiment, the communication holes 50 of the buffer member 5A are formed inside the buffer member 5A so that the ejected substances (ejected gases) ejected from the safety valves of the battery modules 21a, 21b, 21c, and 21d can pass through and be discharged from the opening portion 50b to the side remaining space 34 in the housing 3. Thereby, it is possible to suppress the high-temperature ejected substances (ejected gases) ejected from any of the safety valves of the battery modules 21a, 21b, 21c, and 21d from being ejected directly above the battery stack 2 through the communication holes 50, and thus it is possible to suppress the temperature rise of the upper housing 31. Therefore, it is possible to reduce the heat insulating material of the floor located on the upper housing 31 in the vehicle, ensure the safety of the vehicle occupants, and reduce the number of components.

[0044] Next, a fourth embodiment of the battery pack of the present utility model will be described. In addition, in this embodiment, the description of the same components as those in the first embodiment will be appropriately omitted.

[0045] Figure 5 FIG. 4 is a cross-sectional view showing a schematic structure of the battery pack 1 according to the fourth embodiment when viewed from above. Figure 6 It represents Figure 5 FIG. B-B cross-section of the battery pack 1 shown. In addition, Figure 5 The C-C cross-section of the battery pack 1 shown is the same as the A-A cross-section of the battery pack 1 according to the first embodiment shown in Figure 2 , so the illustration and description are omitted.

[0046] In the battery pack 1 according to the fourth embodiment, as shown in Figure 5 , buffer members 5 are arranged around the entire circumference (all sides) of the battery stack 2 (battery module) in a plan view. In addition, in the battery pack 1 according to the fourth embodiment, as shown in Figure 6 , the buffer member 5 is divided into buffer members 5a, 5b, 5c, 5d in the height direction. The buffer members 5a, 5b, 5c, 5d are respectively in contact with the side surfaces of the battery modules 21a, 21b, 21c, 21d in the vehicle width direction. In the height direction, the heights (thicknesses) of the buffer members 5a, 5b, 5c, 5d are greater than or equal to the heights (thicknesses) of the corresponding battery modules 21a, 21b, 21c, 21d.

[0047] In addition, in the battery pack 1 according to the fourth embodiment, on at least one of the four side surfaces of the battery stack 2 in the vehicle width direction and the vehicle longitudinal direction, as shown in Figure 5 in the C-C cross-section (refer to Figure 2 ), the buffer member 5 is continuously in contact with the battery modules 21a, 21b, 21c, 21d in the height direction.

[0048] In the battery pack 1 according to the fourth embodiment, since the side surfaces of the battery modules 21a, 21b, 21c, 21d are entirely covered by the buffer member 5, heat generated by the curing of the filling member 4 is difficult to transfer to the battery modules 21a, 21b, 21c, 21d. Therefore, in the battery pack 1 according to the fourth embodiment, a filling member 4 with faster curing can be selected, so the time required for manufacturing the battery pack 1 can be shortened.

Claims

1. A battery pack, wherein a power storage device is housed in a housing composed of a lower housing and an upper housing, wherein: The lower shell and the upper shell are opposite to each other in a first direction, In a second direction perpendicular to the first direction, a filling member is filled between the lower case and the power storage device. In the second direction, a buffer member is provided between the filling member and the power storage device. The Young's modulus of the buffer member is smaller than the Young's modulus of the filling member.

2. The battery pack according to claim 1, characterized in that: The power storage device includes a plurality of battery modules stacked in the first direction. The buffer member is located at a position overlapping with the battery module when viewed from the second direction.

3. The battery pack according to claim 1 or 2, characterized in that: The buffer member has a communication hole communicating with a remaining space in the housing.

4. The battery pack according to claim 1 or 2, characterized in that: The plurality of battery modules stacked in the first direction included in the power storage device each have a safety valve, The buffer member is dissolved by the ejected material ejected from the safety valve or penetrated by the pressure of the ejected material.

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