Battery module

Abstract

The discharged material from the battery module housing is guided in a desired direction while minimizing damage to the housing caused by the discharged material. [Solution] The battery module 1 comprises a battery cell 10, a housing 20 that houses the battery cell 10, and a metal plate 30 that at least partially overlaps the housing 20. The metal plate 30 is configured to deflect waste discharged from the housing 20.

Description

Technical Field

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

Background Art

[0002] In recent years, various battery modules have been developed. A battery module includes a battery cell and a housing that accommodates the battery cell.

[0003] Patent Document 1 describes a lithium ion battery module. The battery module includes a plurality of battery cells, a cover disposed over the plurality of battery cells, and a gas guide structure provided on one side of each battery cell. The gas guide structure covers the battery cell. A discharge path is formed between the cover and the gas guide structure.

[0004] Patent Document 2 describes a battery module. The battery module includes a battery cell, a cover plate that covers the battery cell, and a protective cover that accommodates the cover plate. The cover plate has a plurality of pressure release holes. The protective cover has a plurality of other pressure release holes.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0006] Malfunctions in battery cells can cause relatively high-temperature emissions, such as gases and ejected materials, to be released from the battery cells. These emissions are discharged from the housing that contains the battery cells. In battery modules, it may be necessary to guide these emissions in a desired direction. However, if the emissions are deflected by the structure of the housing itself, it can be difficult to prevent damage to the housing caused by the relatively high-temperature emissions.

[0007] One example of the object of the present invention is to guide waste discharged from the housing of a battery module in a desired direction while suppressing damage to the housing caused by the waste. Other objects of the present invention will become apparent from the description herein. [Means for solving the problem]

[0008] One aspect of the present invention is as follows: 1. Battery cell and, A housing for the aforementioned battery cell, A structure that overlaps at least partially with the aforementioned housing, Equipped with, The aforementioned structure is a battery module configured to deflect waste discharged from the housing. 2. The structure is a heat-resistant battery module as described in 1. 3. The battery module according to 1. or 2., wherein the structure is at least partially made of metal. 4. The battery module according to any one of 1 to 3, wherein the melting point of the structure is higher than the melting point of the portion of the housing from which the waste is discharged. 5. The structure is at least partially composed of iron and an iron alloy, The battery module according to any one of 1 to 4, wherein the portion of the housing from which the waste is discharged is at least partially made of aluminum and aluminum alloy. 6. The battery module according to any one of 1 to 5, wherein the structure defines a hole opening in a direction not perpendicular to the portion of the housing from which the waste is discharged. [Effects of the Invention]

[0009] According to the above embodiment of the present invention, waste discharged from the housing of the battery module can be guided in a desired direction while suppressing damage to the housing caused by the waste. [Brief explanation of the drawing]

[0010] [Figure 1] This is an exploded perspective view of a battery module according to an embodiment. [Figure 2] This is a top view of a battery module according to an embodiment. [Figure 3] This is a top view of a battery module according to an embodiment, with the metal plate removed. [Figure 4] This is a cross-sectional view along line AA in Figure 2. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0012] Figure 1 is an exploded perspective view of the battery module 1 according to the embodiment. Figure 2 is a top view of the battery module 1 according to the embodiment. Figure 3 is a top view of the battery module 1 according to the embodiment with the metal plate 30 removed. Figure 4 is a cross-sectional view along line AA in Figure 2.

[0013] In FIGS. 1 to 4, for explanatory purposes, an X-axis, a Y-axis, and a Z-axis respectively indicating the X direction, Y direction, and Z direction are shown. In FIGS. 2 and 3, a white circle with a black dot indicating the Z-axis shows that the arrow of the Z-axis is directed toward the front side of the paper surface. In FIG. 4, a white circle with a black dot indicating the X-axis shows that the arrow of the X-axis is directed toward the front side of the paper surface. The X direction indicates the front-rear direction of the battery module 1. The Y direction is one of the directions perpendicular to the X direction. The Y direction indicates the left-right direction of the battery module 1. The Z direction is a direction perpendicular to both the X direction and the Y direction. The Z direction indicates the up-down direction of the battery module 1. The direction pointed by the tip of the arrow on the X-axis, the direction pointed by the tip of the arrow on the Y-axis, and the direction pointed by the tip of the arrow on the Z-axis respectively indicate the rear direction, the right direction, and the upper direction of the battery module 1. The relationship between the X direction, Y direction, and Z direction and the front-rear direction, left-right direction, and up-down direction of the battery module 1 is not limited to this example.

[0014] Hereinafter, unless otherwise specified, the +X side or +X refers to the side indicated by the tip of the arrow on the X-axis, and the -X side or -X refers to the side opposite to the side indicated by the tip of the arrow on the X-axis. Hereinafter, unless otherwise specified, the +Y side or +Y refers to the side indicated by the tip of the arrow on the Y-axis, and the -Y side or -Y refers to the side opposite to the side indicated by the tip of the arrow on the Y-axis. Hereinafter, unless otherwise specified, the +Z side or +Z refers to the side indicated by the tip of the arrow on the Z-axis, and the -Z side or -Z refers to the side opposite to the side indicated by the tip of the arrow on the Z-axis.

[0015] A battery module 1 according to an embodiment includes a plurality of battery cells 10, a housing 20, and a metal plate 30.

[0016] As shown in Figure 1, the plurality of battery cells 10 are stacked in the Y direction. Each battery cell 10 has a substantially rectangular parallelepiped shape having a pair of surfaces substantially perpendicular to the X direction, a pair of surfaces substantially perpendicular to the Y direction, and a pair of surfaces substantially perpendicular to the Z direction. The lengths of the respective sides of the battery cell 10 increase in the order of the side substantially parallel to the Y direction, the side substantially parallel to the Z direction, and the side substantially parallel to the X direction. The shape of each battery cell 10 is not limited to the example shown in Figure 1. The plurality of battery cells 10 integrally form a substantially rectangular parallelepiped shape having a pair of surfaces substantially perpendicular to the X direction, a pair of surfaces substantially perpendicular to the Y direction, and a pair of surfaces substantially perpendicular to the Z direction.

[0017] As shown in Figure 1, each battery cell 10 includes an exterior material 11, a positive electrode tab 12, and a negative electrode tab 13. The exterior material 11 seals a battery element and an electrolytic solution (not shown). In one example, the battery element includes positive electrodes and negative electrodes alternately stacked in the Y direction, and a separator positioned between the positive electrodes and the negative electrodes. The structure of the battery element is not limited to this example. The positive electrode tab 12 is drawn out from one of the +X side and the -X side of the exterior material 11. The positive electrode tab 12 and the positive electrode of the battery element are electrically connected to each other. The negative electrode tab 13 is drawn out from the other of the +X side and the -X side of the exterior material 11. The negative electrode tab 13 and the negative electrode of the battery element are electrically connected to each other.

[0018] In the example shown in Figure 1, the plurality of battery cells 10 connected in parallel are connected in series in order from the battery cell 10 on the +Y side to the battery cell 10 on the -Y side. The electrical connection of the battery cells 10 is not limited to the example shown in Figure 1. For example, single battery cells 10 may be connected in series with each other.

[0019] The housing 20 houses multiple battery cells 10. As can be seen from Figures 1 to 3, the housing 20 has a roughly rectangular parallelepiped shape with a pair of faces substantially perpendicular to the X direction, a pair of faces substantially perpendicular to the Y direction, and a pair of faces substantially perpendicular to the Z direction. As shown in Figure 1, the housing 20 includes a top plate 21, a first side plate 22, a second side plate 23, a front plate 24, a rear plate 25, and a bottom plate 26. As shown in Figure 1, the top plate 21 covers the +Z side of the multiple battery cells 10. The top plate 21 is positioned substantially perpendicular to the Z direction. The first side plate 22 covers the +Y side of the multiple battery cells 10. The first side plate 22 is positioned substantially perpendicular to the Y direction. The second side plate 23 covers the -Y side of the multiple battery cells 10. The second side plate 23 is positioned substantially perpendicular to the Y direction. The front plate 24 covers the -X side of the multiple battery cells 10. The front plate 24 is positioned approximately perpendicular to the X direction. The rear plate 25 covers the +X side of the multiple battery cells 10. The rear plate 25 is positioned approximately perpendicular to the X direction. The bottom plate 26 covers the -Z side of the multiple battery cells 10 with thermal glue 261 positioned between the multiple battery cells 10 and the bottom plate 26. The bottom plate 26 is positioned approximately perpendicular to the Z direction. The thermal conductivity of the thermal glue 261 makes it easier to conduct heat generated from the multiple battery cells 10 to the bottom plate 26.

[0020] Each plate constituting the housing 20 is, for example, at least partially made of aluminum and an aluminum alloy. When each plate constituting the housing 20 is made of at least one of aluminum and an aluminum alloy, the weight of the housing 20 can be reduced while maintaining the strength of the housing 20, compared to when each plate constituting the housing 20 is at least partially made of at least one of iron and an iron alloy such as stainless steel. Each plate constituting the housing 20 may be at least partially made of at least one of iron and an iron alloy such as stainless steel instead of aluminum and an aluminum alloy.

[0021] As shown in Figures 1, 3, and 4, the top plate 21 defines a plurality of discharge holes 211. In the examples shown in Figures 1 and 3, the plurality of discharge holes 211 are arranged at approximately equal intervals in the Y direction, approximately in the center of the top plate 21 in the X direction. Viewed from the +Z side, each discharge hole 211 is approximately circular in shape. As shown in Figure 4, each discharge hole 211 penetrates the top plate 21 in the Z direction. The number, shape, and position of the discharge holes 211 are not limited to the examples shown in Figures 1, 3, and 4.

[0022] The metal plate 30 is at least partially composed of metal. For example, the metal plate 30 is at least partially composed of iron and an iron alloy, such as stainless steel. Therefore, the metal plate 30 can have heat resistance while its strength is higher than that of a flexible member such as a heat-resistant sheet.

[0023] As shown in Figure 1, the metal plate 30 has a main plate 31, a first bent plate 32, and a second bent plate 33. Viewed from the +Z side, the main plate 31 has a roughly rectangular shape with a pair of short sides that are roughly parallel to the X direction and a pair of long sides that are roughly parallel to the Y direction. The main plate 31 is positioned roughly perpendicular to the Z direction. The first bent plate 32 is bent to the -Z side relative to the +Y side end of the main plate 31. The second bent plate 33 is bent to the -Z side relative to the -Y side end of the main plate 31.

[0024] As shown in Figures 1 and 2, with the housing 20 and metal plate 30 attached to each other, the top plate 21 and main plate 31 overlap at least partially in the Z direction. Specifically, as shown in Figure 3, a first flange 221 is provided in the approximate center portion of the first side plate 22 in the X direction. The tip of the first bent plate 32 and the first flange 221 are fastened to each other by fasteners such as bolts and nuts. As shown in Figure 3, two second flanges 231 are provided in the approximate center portion of the second side plate 23 in the X direction. The two branched tips of the second side plate 23 and the two second flanges 231 are fastened to each other by fasteners such as bolts and nuts. With the tip of the first bent plate 32 and the first flange 221 fastened to each other, and the tip of the second bent plate 33 and the second flange 231 fastened to each other, the housing 20 and metal plate 30 are attached to each other. With the housing 20 and the metal plate 30 attached to each other, the main body plate 31 is positioned on the +Z side with respect to the approximate center of the top plate 21 in the X direction. The +Z surface of the top plate 21 and the -Z surface of the main body plate 31 may be joined to each other by a bonding material such as double-sided tape or adhesive.

[0025] The arrangement of the metal plate 30 is not limited to the method according to the embodiment. For example, with the metal plate 30 attached to the peripheral members of the housing 20, the top plate 21 and the main body plate 31 may overlap at least partially in the Z direction.

[0026] As shown in Figures 1, 3, and 4, the main plate 31 has a plurality of ridges 311 that are raised on the +Z side. As shown in Figures 1 and 3, the plurality of ridges 311 are arranged at approximately equal intervals in the Y direction. In the embodiment, the plurality of discharge holes 211 and the plurality of ridges 311 are at least partially overlapping each other in the Z direction in a one-to-one correspondence. As shown in Figures 1 and 4, each ridge 311 defines a deflection hole 312 that opens on the -Y side. As shown in Figure 4, the discharge holes 211 and the deflection holes 312 are in communication with each other. The number and arrangement of the ridges 311 are not limited to the examples shown in Figures 1, 3, and 4. For example, the discharge holes 211 and the ridges 311 do not have to overlap in the Z direction. The opening direction of the deflection holes 312 may be different from the -Y direction.

[0027] Referring to Figure 4, the flow of waste generated from the battery cell 10 and discharged from the housing 20 will be explained. Due to a malfunction in the battery cell 10, relatively high-temperature waste such as gas and ejected material may be generated from the battery cell 10. In Figure 4, the dashed arrows extending from the battery cell 10 indicate the flow of this waste. Refer to Figures 1 to 3 as needed.

[0028] As shown by the dashed arrows extending from the battery cell 10 in Figure 4, the waste generated from the battery cell 10 passes through the discharge hole 211 and is then guided to the deflection hole 312 by the portion of the raised 311 that covers the discharge hole 211. Therefore, in this embodiment, the approximate center of the top plate 21 in the X direction is the portion from which waste is discharged from the housing 20. After being guided to the deflection hole 312, the waste is discharged to the -Y side through the deflection hole 312. Thus, the main plate 31 is a structure configured to deflect the waste discharged from the housing 20. As a result, the waste discharged from the housing 20 can be guided in a desired direction according to the opening direction of the deflection hole 312.

[0029] In this embodiment, the waste discharged from the discharge hole 211 is deflected not by the structure of the top plate 21 itself, but by a main body plate 31 provided separately from the top plate 21. Therefore, compared to the case where the waste is deflected by the structure of the top plate 21 itself, damage to the top plate 21 due to the waste can be suppressed. Furthermore, in this embodiment, the main body plate 31 has heat resistance. Specifically, the melting point of the main body plate 31 is higher than the melting point of the top plate 21. For example, the top plate 21 is at least partially composed of at least one of aluminum and an aluminum alloy, and the main body plate 31 is at least partially composed of at least one of iron and an iron alloy. Therefore, damage to the main body plate 31 due to waste generated from the battery cell 10 can be suppressed.

[0030] In this embodiment, the deflection hole 312 is permanently opened by the protrusion 311. Therefore, compared to the case where the deflection hole is configured to be openable and closable by a mechanism such as a hinge, the structure around the deflection hole 312 of the main plate 31 can be simplified, and the strength around the deflection hole 312 of the main plate 31 can be improved.

[0031] In this embodiment, the discharged material from the discharge hole 211 can be prevented from being sprayed to the +Z side. For example, a portion of the housing that houses the battery module 1 may be located on the +Z side relative to the top plate 21. If the discharged material from the discharge hole 211 is sprayed to the +Z side, it may be necessary to protect the component located on the +Z side relative to the top plate 21 from the discharged material with a heat-resistant sheet. In this embodiment, such a heat-resistant sheet can be made unnecessary, thereby reducing the cost of the heat-resistant sheet.

[0032] The -Z surface of the top plate 21 may be covered with an insulating sheet that blocks a plurality of discharge holes 211. The insulating sheet is configured to be at least partially destroyed by the discharge generated from the battery cell 10. For example, the insulating sheet may be configured to break due to the pressure of the discharge or melt due to the temperature of the discharge. When the battery cell 10 is operating normally, the airtightness of the battery module 1 can be improved by blocking the plurality of discharge holes 211 with the insulating sheet. When a malfunction occurs in the battery cell 10, the discharge can be discharged through the discharge holes 211 and deflection holes 312 by at least partially destroying the insulating sheet.

[0033] The flow of the discharged material is not limited to the example shown in Figure 4. The discharged material can be deflected in a desired direction depending on the opening direction of the deflection holes 312. The deflection holes 312 can be opened in a direction not perpendicular to the top plate 21. For example, the deflection holes 312 may be opened on the +Y side, the +X side, or the -X side. Alternatively, the deflection holes 312 may be opened obliquely to the Z direction. The opening directions of the multiple deflection holes 312 do not have to be the same and may differ depending on the deflection hole 312. The multiple deflection holes 312 do not have to be arranged in a line. For example, when viewed from the +Z side, the multiple deflection holes 312 may be located around the approximate center of the top plate 21, with each deflection hole 312 opening toward approximately the center or opposite the approximate center of the top plate 21.

[0034] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted. [Explanation of Symbols]

[0035] 1 Battery module, 10 Battery cells, 11 Outer casing, 12 Positive electrode tab, 13 Negative electrode tab, 20 Housing, 21 Top plate, 211 Discharge hole, 22 First side plate, 221 First flange, 23 Second side plate, 231 Second flange, 24 Front plate, 25 Rear plate, 26 Bottom plate, 261 Thermal glue, 30 Metal plate, 31 Main body plate, 311 Raised section, 312 Deflection hole, 32 First bent plate, 33 Second bent plate

Claims

1. Battery cell and A housing for the aforementioned battery cell, A structure that overlaps at least partially with the aforementioned housing, Equipped with, The aforementioned structure is a battery module configured to deflect waste discharged from the housing.

2. The battery module according to claim 1, wherein the structure is heat-resistant.

3. The battery module according to claim 1 or 2, wherein the structure is at least partially made of metal.

4. The battery module according to claim 1 or 2, wherein the melting point of the structure is higher than the melting point of the portion of the housing from which the waste is discharged.

5. The aforementioned structure is at least partially composed of iron and an iron alloy, The battery module according to claim 1 or 2, wherein the portion of the housing from which the waste is discharged is at least partially composed of aluminum and an aluminum alloy.

6. The battery module according to claim 1 or 2, wherein the structure defines a hole opening in a direction not perpendicular to the portion of the housing from which the waste is discharged.

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