Power storage device

Abstract

To provide a power storage device capable of suppressing the heat generation from a fastening part of a bus bar construction member with a simple structure.SOLUTION: A power storage device 4 comprises: a plurality of power storage modules arranged in parallel to an arrangement direction; a housing case 10 that houses the plurality of power storage modules; a first bus bar 50 that connects the adjacent power storage modules in the arrangement direction; and a second bus bar 60 that is connected to any one of the plurality of power storage modules, and is distributed into the housing case 10. The first bus bar 50 contains a part covered with a heat-resistant member 51. The second bus bar 60 is constructed by fastening a plurality of bus bar construction members 61 and 62 with a fastening part 70. The fastening part 70 is positioned to a lower direction of the part covered with the heat-resistant member 51 from the first bus bar 50.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage device mounted on a vehicle. [Background technology]

[0002] As a conventional energy storage device, JP 2022-94702 A (Patent Document 1) discloses a technology that includes a bus bar that electrically connects battery modules contained in a housing case, or a bus bar that electrically connects a battery module to an electrical component, and an expanded graphite layer is disposed on the surface of an insulating member that covers the surface of the center of the bus bar. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-94702 Summary of the Invention [Problem to be solved by the invention]

[0004] When one bus bar is arranged in a housing case, the bus bar may be formed to be long, which reduces the productivity of the bus bar. In order to improve the productivity of the bus bar, it is possible to configure the bus bar arranged in the housing case by fastening multiple bus bar components. However, because a high-voltage current flows through the fastening parts of the bus bar components, it is difficult to wrap a heat-resistant material or the like around the fastening parts.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide an energy storage device that is capable of suppressing heat generation from fastening portions of busbar components with a simple configuration. [Means for solving the problem]

[0006] An energy storage device according to the present disclosure includes a plurality of energy storage modules arranged side by side in an arrangement direction, a housing case that houses the plurality of energy storage modules, a first bus bar that connects the energy storage modules adjacent to each other in the arrangement direction, and a second bus bar that is connected to one of the plurality of energy storage modules and arranged in the housing case. The first bus bar includes a portion covered with a heat-resistant member. The second bus bar is formed by fastening a plurality of bus bar components with fastening portions. The fastening portions are located below the portions of the first bus bar that are covered with the heat-resistant member. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an energy storage device that can suppress heat generation from fastening portions of busbar components with a simple configuration. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a vehicle equipped with an electricity storage device according to an embodiment. [Diagram 2] 1 is a schematic perspective view of an electricity storage device according to an embodiment; [Diagram 3] 2 is a plan view showing the inside of the power storage device according to the embodiment; FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference characters in the drawings, and the description thereof will not be repeated.

[0010] Fig. 1 is a schematic diagram showing a vehicle equipped with a power storage device according to an embodiment of the present invention. With reference to Fig. 1, a vehicle 1 according to the embodiment of the present invention will be described.

[0011] The vehicle 1 is a hybrid vehicle capable of running using at least one of the power of a motor and an engine, or an electric vehicle that runs on driving force obtained from electric energy. The vehicle 1 includes a vehicle body 2, an electricity storage device 4, front wheels 5, and rear wheels 6. The vehicle body 2 includes a floor panel 9. The floor panel 9 forms the bottom surface of the vehicle body 2. The electricity storage device 4 is provided, for example, on the lower surface of the floor panel 9. Note that the electricity storage device 4 may be disposed between the floor panel 9 and a seat.

[0012] Fig. 2 is a schematic perspective view of the electricity storage device according to the embodiment. Fig. 3 is a plan view showing the inside of the electricity storage device according to the embodiment. Fig. 3 shows the electricity storage device 4 in a state where an upper case 11, which will be described later, is removed. The electricity storage device 4 according to the embodiment will be described with reference to Figs. 2 and 3.

[0013] As shown in Fig. 2, the electricity storage device 4 includes a storage case 10. The storage case 10 is a case body whose length direction is a first direction DR1 and whose width direction is a second direction DR2 perpendicular to the first direction DR1. The electricity storage device 4 is mounted on the vehicle 1, for example, such that the first direction DR1 is parallel to the front-rear direction of the vehicle 1 and the second direction DR2 is parallel to the width direction of the vehicle 1. The height direction of the storage case 10 is perpendicular to the first direction DR1 and the second direction DR2, and is parallel to the up-down direction.

[0014] The housing case 10 includes an upper case 11 and a lower case 12. The lower case 12 has a box shape that opens upward. The lower case 12 is formed of a metal material such as an aluminum alloy. The lower case 12 is fixed to the floor panel 9 by a fixing member such as a bracket.

[0015] Upper case 11 closes the opening of lower case 12. Upper case 11 may be made of a metal material such as an aluminum alloy, or may be made of resin. When upper case 11 is made of resin, the weight of storage case 10 can be reduced.

[0016] 3, the energy storage device 4 further includes a plurality of energy storage modules 20, a plurality of first bus bars 50, and a second bus bar 60. The plurality of energy storage modules 20, the plurality of first bus bars 50, and the second bus bar 60 are housed in a housing case 10.

[0017] The multiple power storage modules 20 are arranged side by side at intervals in the first direction DR1. Each of the multiple power storage modules 20 includes multiple power storage stacks 21. For example, the multiple power storage stacks 21 are arranged in two rows and two columns when the first direction DR1 is the row direction and the second direction DR2 is the column direction. The arrangement of the power storage modules 20 is not limited to the above and can be set appropriately. The power storage module 20 may be composed of a single power storage stack 21.

[0018] The power storage stack 21 includes a plurality of power storage cells 22 (see FIG. 4). The plurality of power storage cells 22 are arranged in one power storage stack 21 along the second direction DR2. The power storage cells 22 are, for example, secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries. The power storage cells 22 have, for example, a rectangular shape. The secondary batteries may use a liquid electrolyte or a solid electrolyte. The power storage cells 22 may also be capacitors.

[0019] The multiple first bus bars 50 connect the multiple power storage modules 20 electrically in series. The multiple first bus bars 50 electrically connect the power storage modules 20 adjacent in the first direction DR1 alternately on one side of the second direction DR2 and the other side of the second direction DR2.

[0020] The second bus bar 60 is connected to at least one of the multiple power storage modules 20, and is arranged inside the accommodating case 10. In the present embodiment, the second bus bar 60 is connected to the power storage module 20 located on the furthest one side in the first direction DR1, and extends toward the power storage module 20 located on the furthest other side in the first direction DR1.

[0021] More specifically, the second bus bar 60 extends from the other side to one side of the second direction DR2 between the storage module 20 located at the furthest side in the first direction DR1 and the wall portion of the storage case 10 located on one side of the first direction DR1, and extends from one side to the other side of the first direction DR1 between the wall portion of the storage case 10 located on one side of the second direction DR2.

[0022] The second bus bar 60 includes, for example, three bus bar components 61, 62, and 63. The second bus bar 60 is configured by fastening the three bus bar components 61, 62, and 63 together at fastening portions.

[0023] The busbar component 61 is provided so as to pass between the energy storage module 20 located on the extreme one side in the first direction DR1 and the wall portion of the accommodating case 10 located on the extreme one side in the first direction DR1. An end portion of the busbar component 61 located on the extreme one side in the second direction DR2 is fastened to the busbar component 62. An end portion of the busbar component 61 located on the other side in the second direction DR2 is electrically connected to the energy storage module 20 located on the extreme one side in the first direction DR1. The fastening portions of the busbar components 61, 62 are located below the first busbar 50.

[0024] The busbar component 62 extends along the first direction DR1. The busbar component 62 connects the busbar component 61 and the busbar component 63. An end of the busbar component 62 located on one side in the first direction DR1 is fastened to the busbar component 61. An end of the busbar component 62 located on the other side in the first direction DR1 is fastened to the busbar component 63. The fastening portions of the busbar components 62, 63 are located below the first busbar 50.

[0025] The busbar component 63 is connected to the busbar component 62 and extends along the first direction DR1. The busbar component 63 is provided so as to pass between the power storage module 20 located on the othermost side in the first direction DR1 and the wall portion of the accommodating case 10 located on one side in the second direction DR2.

[0026] In the above description, the number of busbar components is three, but the present invention is not limited thereto, and the number of busbar components may be two or more. In addition, the busbar 60 may connect the power storage module 20 to another electric component, or may connect power storage modules 20 that are not adjacent to each other in the first direction DR1.

[0027] Fig. 4 is a cross-sectional view taken along line IV-IV shown in Fig. 3. For convenience, Fig. 4 illustrates upper case 11. The structure around fastening portion 70 of busbar components 61, 62 will be described with reference to Fig. 4. The structure around fastening portion 70 of busbar components 62, 63 is substantially similar to the structure around fastening portion 70 of busbar components 61, 62, and therefore description thereof will be omitted.

[0028] The fastening portion 70 is configured, for example, by passing a fastening bolt 71 through the ends of the busbar components 61, 62 facing each other in the second direction DR2, and fitting a nut 73 onto the tip of the fastening bolt 71 for tightening. A collar 72 is disposed between the ends of the busbar components 61, 62 facing each other in the second direction DR2, and the fastening bolt 71 is inserted into the collar 72. The fastening portion 70 may be surrounded by an insulating member 80. The insulating member 80 is, for example, a resin member.

[0029] In the power storage module 20 , external terminals 23 of each of the multiple power storage cells 22 are connected in series by a bus bar module 30 .

[0030] The first bus bar 50 is electrically connected to the conductive members of the bus bar modules 30 disposed in each of the power storage modules 20 adjacent to each other in the first direction DR1, thereby electrically connecting the adjacent power storage modules 20 to each other.

[0031] The first bus bar 50 includes a portion covered with a heat-resistant member 51. The heat-resistant member 51 covers a portion of the first bus bar 50 extending along the first direction. The heat-resistant member 51 may be a sheet-like member, a resin member, or a metal member. The heat-resistant member 51 may have insulating properties.

[0032] The above-mentioned fastening portion 70 is located below a portion of the first bus bar 50 that is covered with the heat-resistant member 51. Moreover, the fastening portion 70 is located so as not to protrude outside the portion of the first bus bar 50 that is covered with the heat-resistant member 51 in the second direction DR2 when viewed from the height direction.

[0033] Generally, when the power storage cell 22 included in the power storage module 20 emits gas due to thermal expansion or the like, the gas moves along the ceiling portion 115 of the storage case 10. The gas is at a considerably high temperature and contains debris such as metal foreign matter.

[0034] In this embodiment, as described above, the first bus bar 50 includes a portion covered by the heat-resistant member 51, and when debris moving along the ceiling portion 115 of the accommodation case 10 moves downward, the heat-resistant member 51 can receive the debris. Therefore, even if the insulating member 80 surrounding the fastening portion 70 is lost due to the heat of the high-temperature gas, it is possible to prevent debris from adhering to the fastening portion 70 located below the heat-resistant member 51. As a result, a short circuit at the fastening portion 70 can be prevented, and heat generation from the fastening portion 70 can be suppressed.

[0035] In addition, since the above-mentioned effect can be obtained by disposing the fastening portion 70 below the heat-resistant member 51, there is no need to provide a separate heat-resistant member around the fastening portion 70. This simplifies the configuration for suppressing heat generation from the fastening portion 70.

[0036] In addition, as described above, by making the fastening portion 70 not protrude from the heat-resistant member 51 in the second direction DR2 as well, adhesion of debris to the fastening portion 70 can be further suppressed.

[0037] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0038] 1 vehicle, 2 vehicle body, 3 drive mechanism, 4 power storage device, 5 front wheels, 6 rear wheels, 9 floor panel, 10 housing case, 11 upper case, 12 lower case, 20 power storage module, 21 power storage stack, 22 power storage cell, 23 external terminal, 30 bus bar module, 50 first bus bar, 51 heat-resistant member, 60 second bus bar, 61, 62, 63 bus bar constituent members, 70 fastening portion, 71 fastening bolt, 72 collar, 73 nut, 80 insulating member, 115 ceiling portion.

Claims

[Claim 1] A plurality of storage modules arranged side by side in an arrangement direction; a housing case that houses the plurality of power storage modules; a first bus bar connecting the energy storage modules adjacent to each other in the arrangement direction; a second bus bar connected to any one of the plurality of power storage modules and arranged in the accommodating case; the first bus bar includes a portion covered with a heat-resistant member, the second bus bar is configured by fastening a plurality of bus bar components to each other at fastening portions, the fastening portion is located below a portion of the first bus bar that is covered with the heat-resistant member.

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