Battery pack

Abstract

To provide a battery pack that is appropriately protected when gas is generated in a battery cell.SOLUTION: A battery pack includes: a plurality of battery cells 11; a case body 31 having an opening 30; and a cover 21 that is attached to the case body 31 so as to close the opening 30 and that forms, together with the case body 31, a space 20. Each of the battery cells 11 has: an exterior package that includes a top surface 15 facing the cover 21 and that accommodates an electrode body and an electrolyte; and a gas-release valve 17 that releases gas from inside of the exterior package to the space 20 through the top surface 15 when pressure in the exterior package becomes equal to or more than a predetermined value. The battery pack further includes a plate member 41 that comprises metal or ceramic and that has a main portion 42 disposed between the top surface 15 and the cover 21 in the space 20 and a fixation portion 45 extending from the main portion 42 and being fixed, the main portion 42 being provided with a plurality of through holes 43.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] For example, International Publication No. 2020 / 189590 (Patent Document 1) discloses a battery pack including a secondary battery, a housing for accommodating the secondary battery, and a plate-shaped reinforcing portion extending from one end to the other end in the longitudinal direction of the housing and arranged in the height direction of the secondary battery to reinforce the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 189590 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack disclosed in the above-mentioned Patent Document 1, a housing (case) that houses a secondary battery is composed of a main body part in the shape of a rectangular box with an open top, and a cover that covers the opening of the main body part.

[0005] In such a battery pack, if high-pressure gas leaks from the battery cell into the case in the event of a battery abnormality, there is a concern that the gas leaking from the battery cell will collide with the cover, causing damage to the cover. In addition, the plate-shaped reinforcing part arranged in the height direction of the secondary battery can function as a baffle plate that prevents gas from directly colliding with the cover, but there is a concern that receiving the high-pressure gas will place an excessive load on the fixing part of the reinforcing part.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to solve the above-mentioned problems and to provide a battery pack that is adequately protected when gas is generated in a battery cell. [Means for solving the problem]

[0007] [1] A battery pack comprising: a plurality of battery cells; a case body having an opening; and a cover attached to the case body so as to close the opening and forming, together with the case body, a space to accommodate the plurality of battery cells, wherein the battery cells include a top surface facing the cover, and have an exterior body that accommodates an electrode body and an electrolyte, and a gas outflow valve that allows gas to flow from inside the exterior body through the top surface to the space when the pressure inside the exterior body reaches or exceeds a predetermined value, and further comprising a metal or ceramic plate member having a main portion disposed between the top surface and the cover in the space, and a fixing portion extending from and fixed to the main portion, the main portion having a plurality of through holes.

[0008] In the battery pack configured in this manner, the gas flowing out from the gas outflow valve is received by the main portion, which prevents the gas from directly colliding with the cover and prevents damage to the cover. In this case, by providing a plurality of through holes in the main portion, the pressure that the plate member receives from the gas can be reduced, and excessive load can be prevented from being applied to the fixing portion. Therefore, the battery pack can be appropriately protected when gas is generated in the battery cell.

[0009] [2] The battery pack described in [1], further comprising a duct that forms a gas flow passage communicating with the space and exhausts gas from the space.

[0010] In the battery pack configured in this manner, the speed at which the space is filled with gas (gas filling speed) is reduced by providing a plurality of through holes in the main portion, which ensures sufficient time for the gas to be exhausted from the space through the duct, thereby suppressing an increase in the internal pressure of the space.

[0011] [3] The battery pack according to [1] or [2], wherein the plurality of through holes are provided in positions that do not face the gas outflow valve.

[0012] According to the battery pack configured in this manner, it is possible to more effectively prevent the gas flowing out from the gas outflow valve from directly colliding with the cover.

[0013] [4] The battery pack according to any one of [1] to [3], wherein the plate member is provided between the main portion and the fixed portion and further has a deformation portion that is elastically deformable.

[0014] With a battery pack configured in this manner, when the main part receives gas flowing out from the gas outflow valve, the deformation part elastically deforms, thereby more reliably preventing excessive load from being applied to the fixed part.

[0015] [5] A battery pack as described in any of [1] to [4], further comprising a connector attached to the case body, wherein the plate member further has a shielding portion extending from the main portion and providing shielding between the connector and the battery cell.

[0016] In the battery pack configured in this manner, the shielding portion can prevent high-temperature gas from being directed toward the connector, thereby reducing the thermal load on the connector. Effect of the Invention

[0017] As described above, according to the present invention, it is possible to provide a battery pack that is appropriately protected when gas is generated in a battery cell. [Brief description of the drawings]

[0018] [Figure 1] 1 is a perspective view showing a battery pack according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded view showing the battery pack in FIG. [Diagram 3] FIG. 2 is a perspective view showing a battery cell. [Figure 4] 4 is a cross-sectional view showing a schematic diagram of the battery pack as viewed in the direction of the arrows on line IV-IV in FIG. [Diagram 5]4 is a graph showing the change in the amount of gas in a space caused by gas generation in a battery cell. [Figure 6] 5 is a cross-sectional view showing a first modified example of the battery pack in FIG. [Figure 7] 5 is a cross-sectional view showing a second modified example of the battery pack in FIG. [Figure 8] 8 is a perspective view showing a modified example of the plate member in FIG. 7. [Figure 9] 5 is a cross-sectional view showing a third modified example of the battery pack in FIG. [Figure 10] FIG. 10 is a perspective view showing a plate member in FIG. [Figure 11] 10 is a cross-sectional view showing a modified example of the battery pack in FIG. [Figure 12] FIG. 12 is a perspective view showing a plate member in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0020] Fig. 1 is a perspective view showing a battery pack in an embodiment of the present invention. Fig. 2 is an exploded view showing the battery pack in Fig. 1. Fig. 3 is a perspective view showing a battery cell. Fig. 4 is a cross-sectional view showing a schematic view of the battery pack as seen in the direction of the arrows on line IV-IV in Fig. 1.

[0021] 1 to 4, a battery pack 100 is used as a power source for driving a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV).

[0022] In this specification, for convenience of explaining the structure of the battery pack 100, the axis extending in the stacking direction of the multiple battery cells 11 described later and in the horizontal direction is referred to as the "Y axis," the axis extending in the horizontal direction and perpendicular to the Y axis is referred to as the "X axis," and the axis extending in the vertical direction is referred to as the "Z axis." As shown in Fig. 4, the battery pack 100 basically has a structure that is symmetrical with respect to a virtual plane 110 parallel to the Y-axis-Z-axis plane.

[0023] The battery pack 100 has a plurality of battery cells 11. The plurality of battery cells 11 are stacked in the Y-axis direction. The battery cells 11 are made of lithium ion batteries. The battery cells 11 are square and have a rectangular thin plate shape. The plurality of battery cells 11 are stacked such that the Y-axis direction is the thickness direction of the battery cells 11.

[0024] The battery cell 11 has an exterior body 12. The exterior body 12 is made of a rectangular parallelepiped housing, and forms the external appearance of the battery cell 11. The exterior body 12 contains an electrode assembly and an electrolyte.

[0025] Exterior body 12 has a pair of first side surfaces 14 (14j, 14k), a pair of second side surfaces 13 (13j, 13k), a top surface 15, and a bottom surface 16.

[0026] The first side surface 14 is a plane perpendicular to the X-axis. The first side surface 14 is parallel to the Y-axis direction, which is the stacking direction of the battery cells 11. The first side surface 14j and the first side surface 14k face opposite each other in the X-axis direction. The second side surface 13 is a plane perpendicular to the Y-axis. The second side surface 13 has the largest area among the multiple side surfaces of the exterior body 12. The second side surface 13j and the second side surface 13k face opposite each other in the Y-axis direction. The top surface 15 and the bottom surface 16 each are a plane perpendicular to the Z-axis. The top surface 15 faces upward. The top surface 15 faces a cover 21, which will be described later. The bottom surface 16 faces downward.

[0027] Battery cell 11 further has a gas outflow valve 17. Gas outflow valve 17 is provided on top surface 15. Gas outflow valve 17 is provided at the center position of top surface 15 in the X-axis direction. When the pressure inside exterior body 12 reaches or exceeds a predetermined value, gas outflow valve 17 allows gas to flow from inside exterior body 12 through top surface 15 to the outside of exterior body 12 (space 20 described below).

[0028] The battery cell 11 further has electrode terminals 18, each of which is a pair of a positive terminal 18P and a negative terminal 18N. The electrode terminals 18 are provided on the top surface 15. The positive terminal 18P and the negative terminal 18N are provided apart from each other in the X-axis direction. The positive terminal 18P and the negative terminal 18N are provided on either side of the gas outflow valve 17 in the X-axis direction.

[0029] The multiple battery cells 11 are stacked such that the second side faces 13j face each other and the second side faces 13k face each other between the battery cells 11, 11 adjacent to each other in the Y-axis direction. As a result, the positive electrode terminals 18P and the negative electrode terminals 18N are arranged alternately in the Y-axis direction in which the multiple battery cells 11 are stacked. Between the battery cells 11, 11 adjacent to each other in the Y-axis direction, the positive electrode terminals 18P and the negative electrode terminals 18N arranged in the Y-axis direction are connected to each other by a bus bar (not shown). The multiple battery cells 11 are electrically connected to each other in series.

[0030] The battery cell in the present invention is not limited to a rectangular shape, and may be a cylindrical shape. For example, the multiple battery cells are arranged at intervals from each other in the X-Y plane in an upright position with the cylindrical axis of each battery cell extending in the Z-axis direction. In this case, the gas outflow valve may be provided inside the sealing body that constitutes the top surface of the battery cell.

[0031] As shown in FIG. 2, a cell stack 120 is configured by a plurality of battery cells 11 stacked in the Y-axis direction. The cell stack 120 has a rectangular parallelepiped shape. The length of the cell stack 120 in the Y-axis direction is greater than the length of the cell stack 120 in the Z-axis direction and is greater than the length of the cell stack 120 in the X-axis direction. In a plan view in the Z-axis direction, the cell stack 120 has a rectangular shape with the Y-axis direction being the longitudinal direction and the X-axis direction perpendicular to the Y-axis direction being the lateral direction. The cell stack 120 arranged in the battery pack 100 is not limited to one row, and may be two or more rows.

[0032] The battery pack 100 further has a pair of end plates 91 and a pair of bind bars 66 (not shown in FIG. 2, see FIG. 4). The pair of end plates 91 are respectively arranged at both ends of the cell stack 120 (plurality of battery cells 11) in the Y-axis direction. The pair of bind bars 66 are respectively arranged at both ends of the cell stack 120 in the X-axis direction. The bind bars 66 extend in the Y-axis direction and are connected at both ends to the pair of end plates 91. The multiple battery cells 11 are held together by the pair of end plates 91 and the pair of bind bars 66.

[0033] The battery pack 100 further includes a case body 31 and a cover 21. The case body 31 and the cover 21 are made of metal. The case body 31 and the cover 21 are formed of aluminum, for example. The case body 31 has an opening 30. The opening 30 faces upward. The cover 21 is attached to the case body 31 so as to close the opening 30. The cover 21, together with the case body 31, forms a space 20 that houses a plurality of battery cells 11.

[0034] The case body 31 has a bottom 51, a pair of first side portions 32, and a pair of second side portions 36. The bottom 51 has a wall shape arranged along the X-axis-Y-axis plane with the thickness direction being in the Z-axis direction. The bottom 51 has a rectangular shape in a plan view seen in the Z-axis direction. The cell stack 120 is placed on the bottom 51. A cooling plate 61 is interposed between the bottom 51 and the cell stack 120. The cooling plate 61 is provided with a refrigerant passage 62 extending in the Y-axis direction.

[0035] The pair of first side portions 32 and the pair of second side portions 36 rise from the periphery of the bottom portion 51. The pair of first side portions 32 face each other in the X-axis direction, sandwiching the space 20 therebetween. The first side portions 32 have a wall shape disposed along the Y-axis-axis plane, with the X-axis direction being the thickness direction. The pair of second side portions 36 face each other in the Y-axis direction, sandwiching the space 20 therebetween. The second side portions 36 have a wall shape disposed along the X-axis-axis plane, with the Y-axis direction being the thickness direction.

[0036] The bottom portion 51 is fastened to the pair of first side portions 32 and the pair of second side portions 36 by using a plurality of bolts 52. This configuration is not limited thereto, and the bottom portion 51, the pair of first side portions 32, and the pair of second side portions 36 may be integrally formed from metal.

[0037] The space 20 is formed on the bottom 51 at a position surrounded by the pair of first side portions 32 and the pair of second side portions 36. The opening 30 is defined by upper ends of the pair of first side portions 32 and the pair of second side portions 36. The space 20 is open to the space outside the case body 31 through the opening 30.

[0038] The case body 31 further has a first flange 33. The first flange 33 spreads in a flange-like shape in the surface direction of the X-axis-Y-axis plane from the upper ends of the pair of first side portions 32 and the pair of second side portions 36. The first flange 33 is provided in a frame-like shape along the upper ends of the pair of first side portions 32 and the pair of second side portions 36.

[0039] The cover 21 has a cover body 22 and a second flange 24. The cover body 22 constitutes a main part of the cover 21 and closes the opening 30. The cover body 22 has a saucer shape with the Z-axis direction being the depth direction and opening downward. The second flange 24 spreads in a flange-like shape from the lower end of the cover body 22 in the surface direction of the X-axis-Y-axis plane. The second flange 24 is provided in a frame-like shape along the lower end of the cover body 22. The second flange 24 overlaps with the first flange 33 in the Z-axis direction. The first flange 33 and the second flange 24 are fastened to each other using a plurality of bolts 26, whereby the cover 21 is attached to the case body 31.

[0040] The battery pack 100 further includes a plate member 41. The plate member 41 is made of a material having sufficient heat resistance to not deform even when exposed to high-temperature gas or flame generated from the battery cells 11, and is preferably made of metal or ceramic. The plate member 41 is made of, for example, a metal such as carbon steel, stainless steel, copper, aluminum, or titanium, or a ceramic such as alumina, zirconia, or silica. The surface of the plate member 41 may be coated with a resin material. The thickness of the plate member 41 is smaller than the thickness of the cover 21.

[0041] The plate member 41 has a main portion 42. The main portion 42 is provided in the space 20. The main portion 42 is disposed in the space 20, between the top surface 15 of the battery cell 11 and the cover 21. The main portion 42 faces the top surface 15 in the Z-axis direction. The main portion 42 faces the gas outflow valve 17 in the Z-axis direction. The main portion 42 faces the electrode terminals 18 (positive electrode terminal 18P, negative electrode terminal 18N) in the Z-axis direction. The main portion 42 is provided above the cell stack 120 (battery cells 11).

[0042] The length of the main part 42 in the X-axis direction is greater than the length of the cell stack 120 (battery cells 11) in the X-axis direction. The length of the main part 42 in the Y-axis direction is greater than the length of the cell stack 120 in the Y-axis direction. In plan view in the Z-axis direction, the main part 42 has a rectangular shape with the Y-axis direction as the longitudinal direction and the X-axis direction as the lateral direction. The range of the cell stack 120 in plan view in the Z-axis direction is included in the range of the main part 42 in plan view in the Z-axis direction.

[0043] Distance L between top surface 15 and main portion 42 in the Z-axis direction decreases with increasing distance from gas outflow valve 17 in the X-axis direction. Distance L between top surface 15 and main portion 42 in the Z-axis direction is maximum at a position on imaginary plane 110, and decreases with increasing distance from imaginary plane 110 in the X-axis direction. Distance L between top surface 15 and main portion 42 in the Z-axis direction is constant regardless of the position in the Y-axis direction. Main portion 42 is inclined with respect to each of the X-axis and Z-axis directions.

[0044] 4 in which the battery pack 100 is cut along the X-axis-Z-axis plane, the main portion 42 has a curved cross section. The main portion 42 may have an arc-shaped cross section with a constant curvature. The main portion 42 may have a linear cross section.

[0045] The plate member 41 further has a guide portion 44 and a fixing portion 45. The guide portion 44 extends from the periphery of the main portion 42 in a direction approaching the bottom portion 51 in the Z-axis direction. In the cross-sectional view of the battery pack 100 in Fig. 4 taken along the X-axis-Z axis plane, the guide portion 44 extends from the periphery of the main portion 42 toward a duct 70, which will be described later. The guide portion 44, together with the main portion 42, has a depth direction in the Z-axis direction and is saucer-shaped with an opening facing downward.

[0046] The fixed portion 45 extends from the main portion 42. The fixed portion 45 is provided along the periphery of the guide portion 44 in a plan view in the Z-axis direction. The fixed portion 45 spreads out in a brim-like shape from the lower end of the guide portion 44 in the surface direction of the X-axis-Y-axis plane. The fixed portion 45 is provided in a frame-like shape along the lower end of the guide portion 44.

[0047] The fixed portion 45 is fixed. The fixed portion 45 is a fixed portion (connecting portion) of the plate member 41 for supporting the main portion 42 in the space 20. The fixed portion 45 is sandwiched between the case body 31 and the cover 21. The fixed portion 45 is interposed between the first flange portion 33 and the second flange portion 24. The fixed portion 45 receives a fastening force from the multiple bolts 26 between the first flange portion 33 and the second flange portion 24.

[0048] In this embodiment, the fixing portion 45 corresponds to a gasket 46 for sealing between the case body 31 and the cover 21. That is, the main portion 42 and the gasket 46 are integrally formed from a metal or ceramic plate material. With this configuration, it is possible to reduce the number of parts of the battery pack 100 and the number of steps required for assembling the battery pack 100.

[0049] Space 20 is divided into space 20A and space 20B by plate member 41. Space 20B is surrounded by plate member 41 and cover 21. Space 20A is surrounded by plate member 41 and case body 31. Multiple battery cells 11 are housed in space 20A.

[0050] The main portion 42 is provided with a plurality of through holes 43. The through holes 43 penetrate the main portion 42. The plurality of through holes 43 are provided at intervals from one another. When viewed in the Z-axis direction, the plurality of through holes 43 are provided at intervals from one another in both the Y-axis direction and the Z-axis direction. The plurality of through holes 43 are provided at positions that do not face the gas outflow valve 17 in the Z-axis direction. The space 20A and the space 20B communicate with each other through the plurality of through holes 43.

[0051] The battery pack 100 further has a duct 70. The duct 70 is provided opposite the first side surface 14 of the battery cell 11. The duct 70 forms a gas flow passage 72. The gas flow passage 72 communicates with the space 20. The duct 70 exhausts the gas that has flowed out from the gas outflow valve 17 from the space 20.

[0052] The case body 31 further has a rib portion 34. The rib portion 34 protrudes from the first side portion 32 in the X-axis direction and extends in a rib-like manner along the periphery of the first side portion 32. The duct 70 has a pair of duct covers 71. The pair of duct covers 71 are attached to the pair of first side portions 32, respectively. The duct covers 71 are attached to the first side portions 32 so as to abut against the rib portion 34 in the X-axis direction.

[0053] Duct cover 71, together with first side portion 32, forms gas flow passage 72. Gas flow hole 35 is provided in first side portion 32. Gas flow hole 35 is a hole penetrating first side portion 32, and connects space 20 (20A) and gas flow passage 72. Gas flow passage 72 extends in the Y-axis direction and is open at one end thereof.

[0054] It is assumed that flammable gas may be generated inside the exterior body 12 when a battery abnormality such as an internal short circuit occurs in the battery cell 11. The gas is discharged to the space 20 (20A) through the top surface 15 on which the gas outlet valve 17 is provided (gas flow indicated by arrow A in FIG. 4). The gas collides with the plate member 41, and is guided by the main portion 42 to flow from the center of the space 20 (20A) in the X-axis direction toward both ends, and is further guided by the guide portion 44 to flow downward through the gap between the cell stack 120 and the first side portion 32 (gas flow indicated by arrows B and C in FIG. 4). The gas is discharged from the space 20 (20A) through the gas circulation hole 35 to the gas flow passage 72 (gas flow indicated by arrow D in FIG. 4). The gas flows through the gas flow passage 72 in the Y-axis direction and is discharged to the outside of the duct 70 (gas flow indicated by arrow E in FIG. 1).

[0055] As batteries have become higher capacity in recent years, the amount of gas generated in the battery cells 11 has increased. This can cause high-pressure gas to be ejected from the battery cells 11, or the gas can become hot due to increased gas pressure, resulting in spontaneous combustion. To prepare for such cases, the battery pack 100 of this embodiment is provided with a plate member 41.

[0056] In the space 20, the main part 42 disposed between the top surface 15 of the battery cell 11 and the cover 21 receives the high-pressure gas ejected from the battery cell 11 or the shock waves caused by spontaneous combustion, thereby preventing damage to the cover 21. In addition, the main part 42 also has a heat insulating function that prevents the cover 21 from being exposed to high-temperature gas. In this case, some of the gas received by the main part 42 enters the space 20B from the space 20A through the multiple through holes 43. This reduces the pressure that the plate member 41 receives from the gas, and prevents excessive load from being applied to the fixing part 45. This prevents damage to the cover 21 and the plate member 41.

[0057] Furthermore, in this embodiment, the multiple through holes 43 are provided in positions that do not face the gas outflow valves 17. This configuration makes it possible to more effectively prevent the high-pressure gas ejected from the battery cells 11, or the shock waves caused by spontaneous combustion, from directly impinging on the cover 21.

[0058] Fig. 5 is a graph showing the change in the amount of gas in a space due to gas generation in a battery cell. In Fig. 5, the change in the amount of gas in space 20 in the present embodiment is shown by a solid line 310. The change in the amount of gas in space 20 in a comparative example is shown by a dotted line 320. In the comparative example, a plurality of through holes 43 are not provided in plate member 41. Area Sa in the graph is equal to area Sb in the graph.

[0059] The gas ejected from the battery cell 11 flows from the center of the space 20 (20A) in the X-axis direction toward both ends, and then passes through the gap between the cell stack 120 and the first side portion 32 to finally reach the gas flow hole 35, so that the space 20 is filled with gas immediately after the gas is generated. In this case, the internal pressure of the space 20 increases significantly, which may lead to damage to the case body 31 and the cover 21 that form the space 20. In contrast, in the present embodiment, a portion of the gas received by the main portion 42 of the plate member 41 flows from the space 20A to the space 20B through the multiple through holes 43, thereby reducing the rate at which the space 20 is filled with gas immediately after the gas is generated. As a result, the increase in the internal pressure of the space 20 is suppressed, and damage to the case body 31 and the cover 21 can be more reliably prevented.

[0060] Fig. 6 is a cross-sectional view showing a first modified example of the battery pack in Fig. 4. Fig. 7 is a cross-sectional view showing a second modified example of the battery pack in Fig. 4. Referring to Figs. 6 and 7, in these modified examples, plate member 41 and gasket 46 are provided separately. In the modified example in Fig. 6, fixing portion 45 is fixed to case body 31. In the modified example in Fig. 7, fixing portion 45 is fixed to end plate 91.

[0061] Fig. 8 is a perspective view showing a modification of the plate member in Fig. 7. Referring to Fig. 8, in this modification, plate member 41 further has a deformation portion 81. Deformation portion 81 is provided between main portion 42 and fixed portion 45. Deformation portion 81 is provided at both ends of main portion 42 in the Y-axis direction.

[0062] The deformation portion 81 is configured to be elastically deformable and extends in a wavy manner in the Y-axis direction while changing direction in one direction and then the other direction along the Z-axis direction.

[0063] With this configuration, when gas emitted from the battery cell 11 is received by the main portion 42, the deformation portion 81 elastically deforms. This makes it possible to more reliably prevent the fixing portion 45 from being subjected to an excessive load.

[0064] Fig. 9 is a cross-sectional view showing a third modified example of the battery pack in Fig. 4. Fig. 10 is a perspective view showing a plate member in Fig. 9. With reference to Figs. 9 and 10, in this modified example, plate member 41 and gasket 46 are provided separately. Fixing portion 45 is fixed to cover 21.

[0065] The main portion 42 is provided along the cover body 22. The fixing portion 45 is provided within the plane of the main portion 42. When the main portion 42 is viewed in the Z-axis direction, a plurality of fixing portions 45 are provided at intervals from each other in each of the X-axis and Y-axis directions. A bolt 83 is inserted through the fixing portion 45. The bolt 83 is screwed into a nut 84 provided on the cover body 22.

[0066] The plate member 41 further has a peripheral portion 86. The peripheral portion 86 is formed by bending the peripheral edge of the main portion 42 in a direction approaching the cover body portion 22. The peripheral portion 86 comes into contact with the cover body portion 22, thereby providing a space between the main portion 42 and the cover body portion 22.

[0067] Fig. 11 is a cross-sectional view showing a modified example of the battery pack in Fig. 9. Fig. 12 is a perspective view showing a plate member in Fig. 11. With reference to Figs. 11 and 12, the battery pack 100 further has a connector 96. The connector 96 is attached to the case body 31. The connector 96 is attached to the pair of second side portions 36. Various wirings such as power lines or voltage detection lines are inserted through the connector 96 between the space 20 and the outside thereof.

[0068] In this modified example, the plate member 41 further has a shielding portion 88. The shielding portion 88 extends from the main portion 42. The shielding portion 88 is provided to provide shielding between the connector 96 and the battery cell 11.

[0069] The shielding portion 88 is provided at both ends of the main portion 42 in the Y-axis direction. The shielding portion 88 extends from the main portion 42 in a direction approaching the bottom portion 51 in the Z-axis direction. The shielding portion 88 is disposed in a gap between the connector 96 and the end plate 91 in the Y-axis direction. The connector 96 faces the shielding portion 88 in the Y-axis direction.

[0070] According to this configuration, the shielding portion 88 can prevent high-temperature gas from being directed toward the connector 96. This can reduce the thermal load on the connector 96.

[0071] The above-described various support structures of the plate member 41 and the structures of the deformation portion 81 and the shielding portion 88 may be appropriately combined. For example, the structure of the deformation portion 81 in FIG. 8 may be combined with the plate member 41 supported in the form shown in FIG.

[0072] To summarize the configuration of the battery pack 100 according to the embodiment of the present invention described above, the battery pack 100 according to the embodiment includes a plurality of battery cells 11, a case body 31 having an opening 30, and a cover 21 attached to the case body 31 so as to close the opening 30 and forming, together with the case body 31, a space 20 for accommodating the plurality of battery cells 11. The battery cell 11 includes an exterior body 12 including a top surface 15 facing the cover 21 and accommodating an electrode assembly and an electrolyte, and a gas outflow valve 17 for allowing gas to flow from inside the exterior body 12 to the space 20 through the top surface 15 when the pressure inside the exterior body 12 reaches or exceeds a predetermined value. The battery pack 100 further includes a metal or ceramic plate member 41 having a main portion 42 disposed between the top surface 15 and the cover 21 in the space 20 and a fixing portion 45 extending from and fixed to the main portion 42, and having a plurality of through holes 43 provided in the main portion 42.

[0073] According to battery pack 100 thus configured in the embodiment of the present invention, damage to battery pack 100 can be prevented when gas is generated in battery cell 11.

[0074] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0075] 11 battery cell, 12 exterior body, 13, 13j, 13k second side, 14, 14j, 14k first side, 15 top surface, 16 bottom surface, 17 gas outflow valve, 18 electrode terminal, 18N negative electrode terminal, 18P positive electrode terminal, 20, 20A, 20B space, 21 cover, 22 cover main body, 24 second flange, 26, 52, 83 bolt, 30 opening, 31 case main body, 32 first side, 33 first flange, 34 rib portion, 35 gas circulation hole, 36 second side, 41 plate member, 42 main portion, 43 through hole, 44 guide portion, 45 fixing portion, 46 gasket, 51 bottom, 61 cooling plate, 62 refrigerant passage, 66 bind bar, 70 duct, 71 Duct cover, 72 gas flow passage, 81 deformation portion, 84 nut, 86 peripheral portion, 88 shielding portion, 91 end plate, 96 connector, 100 battery pack, 110 virtual plane, 120 cell stack.

Claims

1. A plurality of battery cells; A case body having an opening; a cover attached to the case body so as to close the opening, the cover forming, together with the case body, a space for accommodating the plurality of battery cells; The battery cell includes: an exterior body including a top surface facing the cover and accommodating an electrode assembly and an electrolyte; a gas outlet valve that allows gas to flow from inside the exterior body through the top surface to the space when the pressure inside the exterior body reaches or exceeds a predetermined value, A battery pack comprising a metal or ceramic plate member having a main portion disposed in the space between the top surface and the cover, and a fixed portion extending from and fixed to the main portion, the plate member having a plurality of through holes formed in the main portion.

2. The battery pack according to claim 1 , further comprising a duct that forms a gas flow passage communicating with the space and exhausts gas from the space.

3. The battery pack according to claim 1 , wherein the plurality of through holes are provided at positions not facing the gas outflow valve.

4. The battery pack according to claim 1 , wherein the plate member further has a deformation portion that is elastically deformable and is provided between the main portion and the fixed portion.

5. A connector is further provided which is attached to the case body.

3. The battery pack according to claim 1, wherein the plate member further includes a shielding portion extending from the main portion and providing a shield between the connector and the battery cell.

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