Storage battery pack and storage battery assembly

Abstract

The invention provides a storage battery pack and a storage battery assembly, which can ensure the sealing performance of a shell and can properly release the pressure on the inner side of the shell when a single battery is in thermal runaway. A storage battery pack is provided with: a unit cell stack in which a plurality of unit cells are stacked; a case having a cell housing space; and an output conductive member, one end side of which is electrically connected to the terminal portion of the single cell, and the other end side of which extends to the outside of the single cell housing space. The housing is provided with a through hole through which the output conductive member passes and a through mask covering the through hole, the through mask has a substantially L-shape, one end side (151) of the through mask is fixed to the housing, the other end side (152) of the through mask covers the through hole (93) via a seal (12), and the other end side (152) rotates around a bent portion (153) provided between the one end side (151) and the other end side (152) when gas is discharged from the safety valve (44).

Description

Technical Field

[0001] The present invention relates to a battery pack including a single cell stack in which a plurality of single cells are stacked, and a battery assembly including a plurality of battery packs. Background Art

[0002] In recent years, in order to ensure that more people have access to affordable, reliable, and sustainable modern energy, research and development related to secondary batteries that contribute to energy efficiency have been actively carried out.

[0003] With the electrification of vehicle drive sources, vehicles are equipped with a battery that supplies power to a drive motor or the like. The battery is constituted by, for example, stacking a plurality of single cells. A valve is provided in the single cell for discharging high-temperature and high-pressure gas generated inside due to an abnormality or the like to the outside of the single cell (for example, Patent Documents 1 and 2).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 7247360

[0007] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2022-86449 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In a battery pack in which a plurality of single cells are housed in a case, a structure is required that can ensure the airtightness inside the case to prevent the intrusion of foreign substances or the like, and can appropriately release the pressure inside the case when gas is released from the single cell into the case due to thermal runaway of the single cell, thereby reducing the impact on the outside.

[0010] The present invention provides a battery pack and a battery assembly that can ensure the airtightness of the case and can appropriately release the pressure inside the case during thermal runaway of the single cell. Moreover, by adopting a compact structure, it contributes to energy efficiency.

[0011] Means for Solving the Problems

[0012] The present invention relates to a battery pack including:

[0013] A single cell stack in which a plurality of single cells having safety valves are stacked;

[0014] A case having a single cell accommodation space for accommodating the single cell stack; and

[0015] A conductive component, one end side of which is electrically connected to the terminal portion of the single cell and is arranged, and the other end side of the conductive component extends to the outside of the single cell accommodation space, wherein,

[0016] A through-hole and a through-hole mask are provided in the housing,

[0017] The conductive component passes through the through-hole from the terminal portion to the outside of the single cell accommodation space,

[0018] The through-hole mask covers the through-hole,

[0019] The through-hole mask has a substantially L-shaped configuration. One end side of the through-hole mask is fixed to the housing, and the other end side of the through-hole mask covers the through-hole via a seal,

[0020] When gas is released from the safety valve of the single cell, the other end side of the through-hole mask rotates about a bending portion provided between the one end side and the other end side of the through-hole mask.

[0021] Furthermore, the present invention relates to a storage battery assembly including a plurality of storage battery groups, wherein,

[0022] Each storage battery group has:

[0023] A single cell laminate in which a plurality of single cells having safety valves are laminated;

[0024] A housing having a single cell accommodation space for accommodating the single cell laminate; and

[0025] A conductive component, one end side of which is electrically connected to the terminal portion of the single cell and is arranged, and the other end side of the conductive component is electrically connected to other storage battery groups outside the housing,

[0026] A through-hole and a through-hole mask are provided in the housing,

[0027] The conductive component passes through the through-hole from the terminal portion to the outside of the single cell accommodation space,

[0028] The through-hole mask covers the through-hole,

[0029] The through-hole mask has a substantially L-shaped configuration. One end side of the through-hole mask is fixed to the housing, and the other end side of the through-hole mask covers the through-hole via a seal,

[0030] When gas is released from the safety valve of the single cell, the through-hole mask rotates about a bending portion provided between the one end side and the other end side of the through-hole mask,

[0031] When gas is released from the safety valve of the single cell, the through-mask restricts the flow direction of the gas flowing outward from the single cell storage space to a specific part and allows the gas to flow outward from the single cell storage space, and restricts the gas from flowing from the outside of the single cell storage space into the single cell storage space.

[0032] Advantages of the Invention

[0033] According to the present invention, the airtightness of the housing can be ensured, and the pressure inside the housing can be appropriately released when the single cell is thermally out of control. Description of the Drawings

[0034] Figure 1 is an external perspective view of the battery pack 10.

[0035] Figure 2 is an exploded perspective view of the battery pack 10.

[0036] Figure 3 is an exploded perspective view of the single cell stack 30.

[0037] Figure 4 is an external perspective view of the battery assembly 100.

[0038] Figure 5 is an external perspective view of the central frame 120.

[0039] Figure 6 is an external perspective view of the bulging part 22.

[0040] Figure 7 is Figure 6 a cross-sectional view taken along the line A-A of

[0041] Figure 8 is a view showing the case where the gas generated when the single cell 40 is thermally out of control is discharged to the outside of the single cell storage space 25 through the through-hole 93.

[0042] Figure 9 is a view showing the flow of gas inside the battery assembly 100 in the case where thermal runaway occurs in a certain battery pack 10.

[0043] Figure 10 is an external perspective view of the through-mask 15 of the modified example.

[0044] Figure 11 is in the case where the through-mask 15 of the modified example is provided Figure 6 a cross-sectional view taken along the line A-A of

[0045] Figure 12This is a diagram showing a case where gases generated during thermal runaway of the single cell 40 in the modified example are discharged to the outside of the single cell accommodation space 25 through the through-hole 93.

[0046] Description of reference numerals:

[0047] 10 Battery pack

[0048] 12 Seal

[0049] 15 Through-hole mask

[0050] 151 One end side

[0051] 152 The other end side

[0052] 153 Bent portion

[0053] 155 Opening

[0054] 20 Housing

[0055] 21 Housing main body

[0056] 23 Housing cover

[0057] 25 Single cell accommodation space

[0058] 30 Single cell stack

[0059] 40 Single cell

[0060] 42 Terminal portion (terminal portion)

[0061] 44 Safety valve

[0062] 61 Output conductive member (conductive member)

[0063] 85 Partition portion (longitudinal wall portion)

[0064] 88 Bottom wall portion

[0065] 93 Through-hole

[0066] 100 Battery pack assembly. Detailed implementation manners

[0067] Hereinafter, an embodiment of the battery pack of the present invention will be described based on the drawings. In addition, in the following description, for convenience, a coordinate system composed of the front-back direction, left-right direction, and up-down direction that are orthogonal to each other will be used for the description. In the drawings, the front is represented as Fr, the rear is represented as Rr, the left side is represented as L, the right side is represented as R, the upper side is represented as U, and the lower side is represented as D. However, these directions have nothing to do with the direction when the battery pack is mounted on the device. For example, when the battery pack is mounted on a vehicle, the up-down direction of the battery pack can face the traveling direction of the vehicle during vehicle mounting, or can face the vehicle width direction.

[0068] [Battery pack]

[0069] As Figure 1 and Figure 2 shown, two single - cell stacks 30 are arranged in the front - to - rear direction inside a box - shaped housing 20 of the battery pack 10. As Figure 3 shown, the single - cell stack 30 has: a plurality of rectangular single cells 40 stacked in the left - to - right direction; and an end plate 31 disposed on one side in the left - to - right direction (the left side in this embodiment), and they are temporarily fixed by a plate clamp 50 with a prescribed pressure. Instead of such a cell - to - pack (CTP) structure, a partition (not shown) may be disposed between adjacent single cells 40. The plate clamp 50 includes: a rectangular lower restraint portion 51 surrounding the bottom surface of the single - cell stack 30, a rectangular upper restraint portion 52 surrounding the upper surface of the single - cell stack 30, and a pair of side restraint portions 53 that sandwich the single - cell stack 30 in the front - to - rear direction, and the lower restraint portion 51 and the pair of side restraint portions 53 are integrally formed. In addition, it may be configured to dispose another end plate, partition, etc. on the other side in the left - to - right direction (the right side in this embodiment) of the single - cell stack 30 so that the single cells 40 do not directly contact the housing 20 on the other side. Further, the single - cell stack 30 may not be a structure in which a plurality of single cells 40 are constrained by a plate clamp 50, that is, it may be a structure in which a plurality of single cells 40 are directly stacked and disposed inside the housing 20.

[0070] The single cell 40 is, for example, a secondary battery such as a lithium - ion battery. A pair of terminal portions 42 and a safety valve 44 disposed between the pair of terminal portions 42 are provided on the upper surface of the single cell 40. The pair of terminal portions 42 includes a positive terminal and a negative terminal. For example, the positive terminal is connected to the negative terminal of an adjacent single cell 40 via a bus bar (not shown), and the negative terminal is connected to the positive terminal of an adjacent single cell 40 via a bus bar (not shown), whereby a plurality of single cells 40 are electrically connected in series. For example, in order to shorten the length of the bus bar, a plurality of single cells 40 may be stacked in a manner that the front - to - rear orientations are alternately reversed.

[0071] The safety valve 44 is a rupture - type valve for preventing the outer can from rupturing when the internal pressure of the single cell 40 abnormally rises. When the internal pressure of the single cell 40 abnormally rises, the safety valve 44 ruptures, and the gas inside the single cell 40 is released to the outside. By disposing the safety valve 44 at the central portion in the front - to - rear direction of the single cell 40, even when a plurality of single cells 40 are stacked in a manner that the front - to - rear orientations are alternately reversed, they can be gathered at the same position in the front - to - rear direction.

[0072] Return Figure 2, the housing 20 includes a housing main body 21 with an upper opening and a housing cover 23 covering the opening of the housing main body 21. The housing main body 21 has a front wall portion 82 and a rear wall portion 84 extending in the left-right direction, a left wall portion 86 connecting the left ends of the front wall portion 82 and the rear wall portion 84, a right wall portion 87 connecting the right ends of the front wall portion 82 and the rear wall portion 84, and a bottom wall portion 88. The space surrounded by the front wall portion 82, the rear wall portion 84, the left wall portion 86, and the right wall portion 87 constitutes a single-cell accommodation space 25 for accommodating the single-cell laminate 30.

[0073] An opening 86a for communicating the single-cell accommodation space 25 with the outside is provided in the left wall portion 86, and a pressure plate 28 is installed with a seal 16 (such as a rubber seal) interposed therebetween. By fixing the pressure plate 28 to the left wall portion 86, the pressure plate 28 contacts the end plate 31 of each single-cell laminate 30 from the opening 86a. The pressure plate 28 presses the end plate 31 inward, whereby the single-cell laminate 30 temporarily fixed by the plate clamp 50 with a prescribed pressure is further pressed in the stacking direction and held in the housing 20. The fixing of the pressure plate 28 to the left wall portion 86 can be a fixing based on welding such as friction stir welding or a bolt fixing. In this way, without modularization, a plurality of single cells 40 can be held in the housing 20 in the battery pack 10, and thus the energy density and space efficiency can be improved.

[0074] In addition, in front of and to the left of the front wall portion 82, a bulging portion 22 is formed so as to protrude further forward from the front wall portion 82. A space is formed inside the bulging portion 22, a first opening 91 is provided on the front surface, and a second opening 92 is also provided on the upper surface. A terminal block 60 for connecting the extraction conductive member 70 is provided in the internal space of the bulging portion 22, constituting an output terminal accommodation space 27. On the terminal block 60, the terminal portion (output terminal) of the output conductive member 61 extending from the single-cell accommodation space 25 to the output terminal accommodation space 27 is electrically connected to the terminal portion of the extraction conductive member 70 that has entered the output terminal accommodation space 27 from the first opening 91. The output conductive member 61 includes a positive-side bus bar 62 and a negative-side bus bar 63, which extend from the positive-side output terminal and the negative-side output terminal of two serially electrically connected single-cell laminates 30, respectively. The extraction conductive member 70 includes a positive-side bus bar 72 and a negative-side bus bar 73, which are connected to an external positive terminal and a negative terminal, respectively.

[0075] In this way, inside the housing 20, there are provided: a single-cell accommodation space 25 that accommodates two single-cell laminates 30; and an output terminal accommodation space 27 that is disposed in front of and to the left of the single-cell accommodation space 25 and connects the extraction conductive member 70. In addition, the number of single-cell laminates 30 accommodated in the single-cell accommodation space 25 can be one or three or more.

[0076] In the front wall portion 82, the height of the region separating the single-cell accommodation space 25 from the output terminal accommodation space 27 (hereinafter, this portion will be referred to as the partition portion 85) is lower than that of other regions. As Figure 7 shown, a gap is provided between the upper end of the partition portion 85 and the housing cover 23, and this gap forms a through-hole 93 through which the output conductive member 61 can pass. The output conductive member 61 has an inverted L shape, with one end extending forward from the through-hole 93 into the output terminal accommodation space 27, and the other end extending downward and fixed to the terminal block 60 provided in the output terminal accommodation space 27.

[0077] A through-hole cover 15 covering the through-hole 93 is provided in the housing 20. The through-hole cover 15 covers the through-hole 93 and a part of the output conductive member 61 via a seal 12 (e.g., a foam seal), and together with the housing cover 23, seals the single-cell accommodation space 25. On the other hand, when the single cell 40 described later undergoes thermal runaway, the through-hole cover 15 deforms, releases the pressure in the single-cell accommodation space 25 from the through-hole 93, and functions as a gas discharge structure of the battery pack 10. Details of the through-hole cover 15 will be described later.

[0078] In addition, as Figure 1 shown, a signal line connector 67 is provided in the output terminal accommodation space 27. The signal line connector 67 is connected to the signal line via a through-hole that communicates the single-cell accommodation space 25 with the output terminal accommodation space 27.

[0079] The housing cover 23 is mounted on the upper surface of the housing body 21 with a first seal 11 (e.g., a rubber seal) interposed therebetween. The housing cover 23 is fixed to the upper surface of the housing body 21 by welding such as friction stir welding. By sealing the single-cell accommodation space 25 from the outside, intrusion of foreign matter into the single-cell accommodation space 25 can be suppressed, and deterioration of the single cell 40 can be suppressed.

[0080] The battery pack 10 configured in this way does not include a junction box for accommodating contactors, fuses, etc., or auxiliary devices such as an ECU. Therefore, when the battery pack 10 is used alone, a junction box and / or an ECU can also be connected to the battery pack 10. In addition, when multiple battery packs 10 are used, the battery packs 10 can be electrically connected to each other using a connection box, and the junction box and / or the ECU can be connected to the connection box. In addition, the junction box and / or the ECU can be incorporated into the connection box, and multiple battery packs 10 can be connected to the junction box and / or the ECU within the connection box.

[0081] Next, referring to Figure 4 and Figure 5, the mounting structure of four battery packs 10 mounted under the floor of the vehicle will be described. In the following description, the front-rear direction, left-right direction (vehicle width direction), and up-down direction are defined based on the vehicle.

[0082] In this mounting structure, as Figure 4 shown, a central frame 120 extending in the vehicle width direction is fixed between a left frame 110L and a right frame 110R that are arranged to extend in the front-rear direction of the vehicle. In addition, in the space in front of the central frame 120, the above two battery packs 10 are arranged side by side, and in the space behind the central frame 120, the above two battery packs 10 are arranged side by side. The four battery packs 10 are fixed to and supported by the left frame 110L, the right frame 110R, and the central frame 120. Hereinafter, this structure will be referred to as the battery pack assembly 100.

[0083] [Battery Pack Assembly]

[0084] The two battery packs 10 in the front of the battery pack assembly 100 are arranged such that the bulging portion 22 is located behind and to the right of them, and the two battery packs 10 in the rear are arranged such that the bulging portion 22 is located in front of and to the left of them. That is, the two battery packs 10 in the front and the two battery packs 10 in the rear are arranged in a state where the bulging portion 22 rotates 180° relative to each other in the front-rear direction with the central frame 120 in between.

[0085] As Figure 5 shown, the central frame 120 of the battery pack assembly 100 is a hollow body with a rectangular cross-section, and is fastened to the left frame 110L and the right frame 110R through flange portions 127 formed at the left and right ends and extending in the front-rear direction.

[0086] Two front communication holes 121a are formed on the front surface 121 of the central frame 120, and are respectively communicated with the first opening portions 91 of the bulging portions 22 of the battery packs 10 formed in the front. Similarly, two rear communication holes 122a are formed on the rear surface 122 of the central frame 120, and are respectively communicated with the first opening portions 91 of the bulging portions 22 of the battery packs 10 formed in the rear. The front communication holes 121a and the rear communication holes 122a are offset in the vehicle width direction. That is, the center positions of the front communication holes 121a in the vehicle width direction and the center positions of the rear communication holes 122a in the vehicle width direction are offset in the vehicle width direction.

[0087] Fastening portions 123 are respectively provided around the front communication hole 121a and the rear communication hole 122a for liquid-tightly fastening the corresponding battery packs 10. Each battery pack 10 is fixed to the central frame 120, for example, by bolt fastening. The central frame 120 has fastening portions 123 on the front surface 121 and the rear surface 122 respectively, and the front surface 121 and the rear surface 122 protrude upward and downward, so that in the cross-section cut along the front-rear direction, it has a high-rigidity cross-sectional shape like an I-beam. In the state where each battery pack 10 is fixed to the central frame 120, the output terminal accommodation space 27 of the battery pack 10 and the hollow region 125 of the central frame 120 become sealed spaces, restricting moisture from entering from the outside.

[0088] The conductive member 70 is taken out and intrudes into the hollow region 125 of the central frame 120 through the first opening 91 from the output terminal accommodation space 27 formed in the bulging portion 22 of each battery pack 10. A bus bar unit (not shown) is arranged in the hollow region 125 of the central frame 120. The bus bar unit includes, for example, a plurality of connecting bus bars and electrically connects four battery packs 10 in series, for example. The central frame 120 is an example of the above-mentioned connection box.

[0089] The battery pack assembly 100 configured in this way is fixed to the frame member of the vehicle by a pair of central support portions 128 provided on the central frame 120 and side support portions 111 provided on the left frame 110L and the right frame 110R, and is arranged under the floor of the vehicle.

[0090] [Gas discharge structure]

[0091] When some abnormalities occur in the single cell 40, such as internal short circuit, the single cell 40 may generate abnormal heat, that is, thermal runaway, and generate high-temperature and high-pressure gas inside the single cell 40. When the pressure of the gas generated inside the single cell 40 rises above a specified value, the safety valve 44 ruptures, and the gas is released to the outside of the single cell 40, that is, the inside of the housing 20.

[0092] The gas released from the safety valve 44 fills the inside of the housing 20, specifically, the single cell accommodation space 25. In order to prevent the intrusion of liquid and foreign matter, the single cell accommodation space 25 is sealed, and the single cell laminate 30 is pressurized and closely arranged, so the single cell accommodation space 25 is likely to become high-pressure. If the pressure inside the single cell accommodation space 25 rises, it may cause the housing 20 to rupture. Therefore, it is necessary to discharge the gas to the outside of the single cell accommodation space 25 to release the pressure inside the single cell accommodation space 25.

[0093] In the present embodiment, as Figure 7 and Figure 8As shown, the through-mask 15 functions as a pressure release portion that discharges gas to the outside of the housing 20 to release the pressure inside the housing 20. The through-mask 15 deforms when the pressure in the single-cell storage space 25 rises, and discharges the gas filling the single-cell storage space 25 from the first opening 91 to the hollow region 125 of the central frame 120 via the through-hole 93 and the output terminal storage space 27. In this way, the through-mask 15 can appropriately release the pressure in the single-cell storage space 25.

[0094] Hereinafter, with reference to Figures 6 to 9 the detailed structure of the through-mask 15 will be described. As Figure 6 and Figure 7 shown, the through-mask 15 is provided outside the single-cell storage space 25, specifically in the output terminal storage space 27, and covers the through-hole 93 from the output terminal storage space 27 side. The through-hole 93 and the through-mask 15 are arranged to extend in the left-right direction along the partition portion 85.

[0095] In the present embodiment, the through-mask 15 is a plate member having a substantially L-shaped configuration. One end side 151 of the through-mask 15 extends horizontally and is fixed to the lower surface of the housing cover 23 outside the single-cell storage space 25. The one end side 151 can be fixed to the housing cover 23 by fastening members such as bolts, or can be fixed to the housing cover 23 by welding such as friction stir welding.

[0096] The other end side 152 of the through-mask 15 extends in the vertical direction and covers the through-hole 93 via the seal 12. The other end side 152 is in close contact with the partition portion 85 and the output conductive member 61 via the seal 12. In this way, the through-mask 15 together with the seal 12 covers the through-hole 93 through which the output conductive member 61 passes, so that the sealing property of the single-cell storage space 25 can be ensured. In addition, it is also possible to prevent foreign matter from entering the single-cell storage space 25 through the through-hole 93.

[0097] As Figure 8 shown, when the single-cell 40 undergoes thermal runaway and the single-cell storage space 25 is filled with gas and the pressure in the single-cell storage space 25 rises, the through-mask 15 deforms and the through-hole 93 opens. Specifically, the through-mask 15 has a bent portion 153 between the one end side 151 and the other end side 152, and rotates around the bent portion 153 under the pressure of the gas, and discharges the gas from the through-hole 93 to the outside of the single-cell storage space 25. In other words, the through-mask 15 is configured as a flap in which the one end side 151 is fixed and the other end side 152 rotates around the bent portion 153.

[0098] In this way, the through mask 15 can cover the through hole 93 through which the output conductive member 61 passes, ensuring the airtightness of the single battery accommodation space 25, and discharging the gas to the outside of the single battery accommodation space 25 to release the pressure when the pressure in the single battery accommodation space 25 rises. Therefore, there is no need to separately provide a pressure relief valve in the housing 20, and the airtightness and pressure release function of the housing 20 can be ensured with a simple structure.

[0099] In addition, the through mask 15 is a substantially L-shaped plate member and can be deformed relatively easily, that is, it can rotate around the bending portion 153. Therefore, the pressure in the single battery accommodation space 25 can be released without breaking the housing main body 21 and the housing cover 23.

[0100] In addition, the safety valve 44 is provided on the upper surface of the single battery 40, and the safety valve 44 and the through hole 93 are arranged relatively close. Therefore, the path of the gas from the safety valve 44 to the through hole 93 can be shortened, and the influence of the high-temperature gas on the single battery 40 can be reduced.

[0101] In addition, the through hole 93 and the through mask 15 are arranged to extend in the left-right direction. Therefore, the exhaust port when discharging the gas to the outside of the single battery accommodation space 25 can be made wider. Therefore, the pressure in the single battery accommodation space 25 can be released sufficiently.

[0102] In the present embodiment, the through mask 15 has a function of restricting the flow of gas from the outside of the single battery accommodation space 25 to the single battery accommodation space 25 (that is, the function as a check valve). Specifically, as Figure 9 shown, even when, for example, the battery pack 10 disposed on the front side and the right side in the battery assembly 100 undergoes thermal runaway and gas is released from the battery pack 10 to the hollow region 125 of the central frame 120, since the through mask 15 functions as a check valve, the gas will not flow into the other three battery packs 10 from the through hole 93. Therefore, it is possible to suppress the chain reaction of thermal runaway in other battery packs 10 due to thermal runaway in a certain battery pack 10.

[0103] In order for this to function as a check valve, the other end side 152 of the through-mask 15 is disposed outside the single battery accommodation space 25 so as to cover the entire through-hole 93. More specifically, the other end side 152 of the through-mask 15 extends downward from a position outside the single battery accommodation space 25 across the lower end of the through-hole 93 (i.e., the upper end of the partition portion 85). In other words, when viewed from the front-rear direction, the other end side 152 of the through-mask 15 extends downward to a position overlapping the partition portion 85. Therefore, even when gas flows from the outside of the single battery accommodation space 25, the other end side 152 of the through-mask 15 does not rotate toward the single battery accommodation space 25, and thus it is possible to suppress the inflow of gas into the single battery accommodation space 25.

[0104] (Modification example)

[0105] As Figure 10 shown, the through-mask 15 of the modification example has an opening 155 through which the output conductive member 61 passes at the other end side 152. The opening 155 is configured in a notch shape.

[0106] As Figure 11 shown, a seal 12 is provided around the through-hole 93 and the opening 155. More specifically, the seal 12 is provided to block the gap between the through-hole 93 and the output conductive member 61 and the gap between the opening 155 and the output conductive member 61. In the gap between the through-hole 93 and the output conductive member 61, the seal 12 is provided across the single battery accommodation space 25 side and the output terminal accommodation space 27 side of the through-hole 93. In the gap between the opening 155 and the output conductive member 61, the seal 12 is provided on the rear surface (i.e., the surface on the single battery accommodation space 25 side) and the front surface (i.e., the surface on the output terminal accommodation space 27 side) of the through-mask 15. According to such a structure, it is possible to reliably seal the periphery of the through-hole 93 and the opening 155 and seal the single battery accommodation space 25.

[0107] As Figure 12 shown, when gas fills the single battery accommodation space 25 due to thermal runaway of the single battery 40, the other end side 152 of the through-mask 15 deforms and the through-hole 93 opens. Specifically, the through-mask 15 has a bent portion 153 between the one end side 151 and the other end side 152, and rotates around the bent portion 153 under the pressure of the gas filling the single battery accommodation space 25, and discharges the gas to the outside of the single battery accommodation space 25 from the through-hole 93. At this time, the seal 12 also breaks due to the pressure of the gas and the through-hole 93 opens, and this situation is omitted from the drawing.

[0108] According to such a structure, there is no need to separately provide a pressure relief valve in the housing 20, and it is possible to ensure the airtightness and pressure release function of the housing 20 with a simple structure.

[0109] As described above, an embodiment of the present invention has been described with reference to the accompanying drawings. However, the present invention is of course not limited to this embodiment. Those skilled in the art should understand that various modification examples or correction examples can obviously be conceived within the scope described in the technical solution, and these modification examples or correction examples also of course belong to the technical scope of the present invention. In addition, within the scope not departing from the gist of the invention, the constituent elements in the above-described embodiments can be arbitrarily combined.

[0110] For example, in the foregoing embodiment, two bus bars (i.e., the positive-side bus bar 62 and the negative-side bus bar 63) pass through the through-hole 93, but it is not limited thereto, and two or more (for example, four) bus bars may also be used.

[0111] In addition, in the above-described embodiment, the battery assembly 100 is composed of two battery packs 10 each in the front, rear, left, and right directions, for a total of four battery packs 10. However, it is not limited thereto, and it may be composed of one battery pack 10 each in the front and rear directions, for a total of two battery packs 10, or two or more battery packs 10 may be arranged in the front and rear directions and two or more battery packs 10 may be arranged in the left and right directions.

[0112] At least the following matters are described in this specification. In the parentheses, corresponding constituent elements, etc. in the above-described embodiment are shown as an example, but it is not limited thereto.

[0113] (1) A battery pack (battery pack 10), comprising:

[0114] A single-cell laminate (single-cell laminate 30) in which a plurality of single cells (single cells 40) each having a safety valve (safety valve 44) are laminated;

[0115] A housing (housing 20) having a single-cell accommodation space (single-cell accommodation space 25) for accommodating the single-cell laminate; and

[0116] A conductive member (output conductive member 61), one end side of the conductive member being electrically connected to the terminal portion (terminal portion 42) of the single cell, and the other end side of the conductive member extending to the outside of the single-cell accommodation space, wherein,

[0117] A through-hole (through-hole 93) and a through-hole mask (through-hole mask 15) are provided in the housing,

[0118] The conductive member passes through the through-hole from the terminal portion to the outside of the single-cell accommodation space,

[0119] The through-hole mask (through-hole mask 15) covers the through-hole,

[0120] The through-mask has a substantially L-shaped configuration. One end side (one end side 151) of the through-mask is fixed to the housing, and the other end side (the other end side 152) of the through-mask airtightly covers the through-opening via a seal member (seal member 12).

[0121] When gas is discharged from the safety valve of the single cell, the other end side of the through-mask rotates about a bending portion (bending portion 153) provided between the one end side and the other end side of the through-mask.

[0122] According to (1), the through-mask and the seal member cover the through-opening through which the conductive member passes, can seal the single cell accommodation space of the housing, and in the case where gas is generated due to thermal runaway of the single cell, the through-opening is opened to release the pressure in the single cell accommodation space. Therefore, there is no need to provide a pressure relief valve in the housing, and the pressure in the housing can be appropriately released with a simple structure.

[0123] (2) The battery pack according to (1), wherein

[0124] The housing has:

[0125] A housing main body (housing main body 21) having a bottom wall portion (bottom wall portion 88) and a longitudinal wall portion (partition wall portion 85) erected from the bottom wall portion, and having the single cell accommodation space surrounded by the bottom wall portion and the longitudinal wall portion; and

[0126] A housing cover (housing cover 23) covering the housing main body from above

[0127] The through-opening is provided between the longitudinal wall portion of the housing main body and the housing cover

[0128] The housing cover extends further outward from the single cell accommodation space than the through-opening

[0129] One end side of the through-mask is fixed to the housing cover at a position outside the single cell accommodation space.

[0130] According to (2), in the case where the through-opening is provided between the longitudinal wall portion of the housing main body and the housing cover, by fixing one end side of the through-mask to the housing cover, the other end side of the through-mask can be rotated about the bending portion during thermal runaway to appropriately release the pressure of the gas in the single cell accommodation space.

[0131] (3) The battery pack according to (2), wherein

[0132] The safety valve is provided on the upper surface of each single cell.

[0133] According to (3), since the safety valve and the through-port are arranged close to each other, the path of the gas from the safety valve to the through-port can be shortened, and the influence of the high-temperature gas on the single cell can be reduced.

[0134] (4) The battery pack according to any one of (1)-(3), wherein,

[0135] When the gas is released from the safety valve to the single cell accommodation space, the through-port cover allows the gas to flow from the safety valve to the outside of the single cell accommodation space and restricts the gas from flowing from the outside of the single cell accommodation space to the single cell accommodation space.

[0136] According to (4), the through-port cover functions as a check valve that restricts the gas from flowing from the outside of the single cell accommodation space to the single cell accommodation space. Therefore, even when thermal runaway occurs in another battery pack connected via the conductive member, the high-pressure gas generated from the other battery pack can be suppressed from flowing into the single cell accommodation space via the through-port.

[0137] (5) The battery pack according to (4), wherein,

[0138] The other end side of the through-port cover is provided outside the single cell accommodation space and covers the entire through-port via the seal.

[0139] According to (5), a through-port cover having a function as a check valve can be realized with a simple structure.

[0140] (6) The battery pack according to any one of (1)-(5), wherein,

[0141] The through-port and the through-port cover are arranged to extend in a direction (left-right direction) orthogonal to the direction (front-back direction) in which the conductive member passes through.

[0142] According to (6), the through-port and the through-port cover can be made wider, so that when gas is generated due to thermal runaway of the single cell, the pressure in the single cell accommodation space can be released sufficiently.

[0143] (7) The battery pack according to any one of (1)-(6), wherein,

[0144] The through-port cover has an opening (opening 155) through which the conductive member passes on the other end side of the through-port cover,

[0145] Around the opening, the seal is provided on both sides of the through-port cover.

[0146] According to (7), the opening portion passing through the mask and the conductive member can be reliably sealed, making the single-cell accommodation space airtight.

[0147] (8) The battery pack according to any one of (1)-(7), wherein

[0148] the single-cell laminate is pressed in the stacking direction of the plurality of single cells with respect to the housing and is accommodated in the single-cell accommodation space.

[0149] According to (8), even in a battery pack in which the single-cell laminate is pressed and tightly accommodated in the housing, the pressure can be appropriately released through the through-mask.

[0150] (9) A battery pack assembly (battery pack assembly 100) including a plurality of battery packs (battery pack 10), wherein

[0151] each battery pack includes:

[0152] a single-cell laminate (single-cell laminate 30) in which a plurality of single cells (single cell 40) each having a safety valve (safety valve 44) are stacked;

[0153] a housing (housing 20) having a single-cell accommodation space (single-cell accommodation space 25) for accommodating the single-cell laminate; and

[0154] a conductive member (output conductive member 61) having one end side electrically connected to the terminal portion (terminal portion 42) of the single cell and the other end side electrically connected to another battery pack outside the housing,

[0155] a through-hole (through-hole 93) and a through-mask (through-mask 15) are provided in the housing,

[0156] the conductive member passes through the through-hole from the terminal portion to the outside of the single-cell accommodation space,

[0157] the through-mask covers the through-hole,

[0158] the through-mask has a substantially L-shaped configuration, one end side (one end side 151) of the through-mask is fixed to the housing, and the other end side (the other end side 152) of the through-mask covers the through-hole via a seal (seal 12),

[0159] When gas is released from the safety valve of the single cell, the through-mask defines the flow direction of the gas flowing from the safety valve to the outside of the single cell accommodation space at a specific part (hollow area 125), allowing the gas to flow from the safety valve to the outside of the single cell accommodation space, and restricting the flow of gas from the outside of the single cell accommodation space to the inside of the single cell accommodation space.

[0160] According to (9), the through-mask and the seal cover the through-hole through which the conductive component passes, can seal the single cell accommodation space of the housing, and in the case of gas generated due to thermal runaway of the single cell, open the through-hole to release the pressure in the single cell accommodation space. Therefore, there is no need to provide a pressure relief valve in the housing, and the pressure in the housing can be appropriately released with a simple structure. In addition, the through-mask functions as a check valve that restricts the flow of gas from the outside of the single cell accommodation space to the inside of the single cell accommodation space. Therefore, even when thermal runaway occurs in other battery packs connected via the conductive component, it is possible to suppress the inflow of high-pressure gas generated from the other battery packs into the single cell accommodation space through the through-hole.

Claims

1. A battery pack, comprising: A single cell laminate in which a plurality of single cells having safety valves are laminated; A case having a single cell accommodation space in which the single cell laminate is accommodated; and A conductive member, one end side of which is electrically connected to a terminal portion of the single cell, and the other end side of which extends to the outside of the single cell accommodation space, wherein, A through-hole and a through-hole cover are provided in the case, The conductive member passes through the through-hole from the terminal portion to the outside of the single cell accommodation space, The through-hole cover covers the through-hole, The through-hole cover has a substantially L-shaped configuration, one end side of the through-hole cover is fixed to the case, and the other end side of the through-hole cover covers the through-hole via a seal, When gas is discharged from the safety valve of the single cell, the other end side of the through-hole cover rotates around a bent portion provided between the one end side and the other end side of the through-hole cover.

2. The battery pack according to claim 1, wherein, The case has: A case main body having a bottom wall portion and a longitudinal wall portion erected from the bottom wall portion, and having the single cell accommodation space surrounded by the bottom wall portion and the longitudinal wall portion; and A case cover that covers the case main body from above, The through-hole is provided between the longitudinal wall portion of the case main body and the case cover, The case cover extends more to the outside of the single cell accommodation space than the through-hole, One end side of the through-hole cover is fixed to the case cover at a position outside the single cell accommodation space.

3. The battery pack according to claim 2, wherein, The safety valve is provided on the upper surface of each single cell.

4. The battery pack according to any one of claims 1-3, wherein, When gas is discharged from the safety valve into the single cell accommodation space, the through-hole cover allows the gas to flow from the safety valve to the outside of the single cell accommodation space and restricts the gas from flowing from the outside of the single cell accommodation space into the single cell accommodation space.

5. The battery pack according to claim 4, wherein, The other end side of the through-hole cover is provided outside the single cell accommodation space and covers the entire through-hole via the seal.

6. The battery pack according to any one of claims 1-3, wherein, The through-hole and the through-hole cover extend in a direction orthogonal to the passing direction of the conductive member.

7. The battery pack according to any one of claims 1-3, wherein, The through-hole cover has an opening through which the conductive member passes on the other end side of the through-hole cover, Around the opening, the seal is provided on both surfaces of the through-hole cover.

8. The battery pack according to any one of claims 1-3, wherein, The single cell laminate is pressed in the stacking direction of the plurality of single cells with respect to the case and is accommodated in the single cell accommodation space.

9. A battery pack assembly, comprising a plurality of battery packs, wherein, Each battery pack has: A single-cell laminate in which a plurality of single cells each having a safety valve are laminated; A case having a single-cell accommodation space for accommodating the single-cell laminate; and A conductive member, one end side of which is electrically connected to a terminal portion of the single cell, and the other end side of which is electrically connected to another battery pack outside the case, A through-hole and a through-hole cover are provided in the case, The conductive member passes through the through-hole from the terminal portion to the outside of the single-cell accommodation space, The through-hole cover covers the through-hole, The through-hole cover has a substantially L-shaped configuration, one end side of the through-hole cover is fixed to the case, and the other end side of the through-hole cover covers the through-hole via a seal, When gas is discharged from the safety valve of the single cell, the through-hole cover rotates about a bent portion provided between the one end side and the other end side of the through-hole cover, When gas is discharged from the safety valve of the single cell, the through-hole cover defines the flow direction of the gas flowing to the outside of the single-cell accommodation space at a specific portion and allows the gas to flow to the outside of the single-cell accommodation space, and restricts the gas from flowing from the outside of the single-cell accommodation space to the single-cell accommodation space.

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