JP7259673B2 - battery pack - Google Patents

Description

The present disclosure relates to battery packs.

Japanese Patent Laying-Open No. 2014-110190 (Patent Document 1) discloses a battery pack including a smoke exhaust path for discharging gas generated inside each unit cell to the outside of the battery pack. In the battery pack disclosed in Patent Document 1, the cooling path and the smoke exhaust path are separated from each other.

JP 2014-110190 A

In the structure of the battery pack disclosed in Patent Literature 1, the gas discharged from the battery cells can be discharged outside the battery pack through the smoke exhaust path while maintaining high temperature.

An object of the present disclosure is to provide a battery pack capable of cooling the heat of gas discharged from battery cells.

The battery pack includes a battery module that includes a plurality of battery cells, a cooler that cools the battery cells, and a smoke exhaust path through which gas discharged from the battery cells flows. , provided in the smoke exhaust path.

According to the above configuration, since at least part of the cooler is provided in the smoke exhaust path, it is possible to cool the heat of the gas discharged from the battery cells, and eventually the gas flows out of the battery pack at a high temperature. can be suppressed.

According to the present disclosure, it is possible to cool the heat of the gas discharged from the battery cell.

1 is a schematic diagram schematically showing battery pack 1 according to the present embodiment. FIG. 2 is a perspective view showing battery modules 10, heat transfer sheets 4, partition walls 5, and coolers 3 provided in the battery pack 1. FIG. FIG. 3 is a plan view from the direction indicated by arrow III in FIG. 2 , and schematically shows the arrangement relationship of the heat transfer sheet 4 and its peripheral configuration when viewed from above. FIG. 2 is a cross-sectional view taken along line IV-IV in FIG. 1 and schematically shows the arrangement relationship of the battery module 10 and its peripheral configuration.

A battery pack according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG. Among the configurations shown in FIGS. 1 to 4, the same or substantially the same configurations are denoted by the same reference numerals, and overlapping descriptions are omitted.

(battery pack)
FIG. 1 is a schematic diagram schematically showing a battery pack 1 according to this embodiment. FIG. 2 is a perspective view showing battery modules 10 , heat transfer sheets 4 , partition walls 5 and coolers 3 provided in battery pack 1 . FIG. 3 is a plan view from the direction indicated by arrow III in FIG. 2, and schematically shows the arrangement relationship of the heat transfer sheet 4 and its peripheral configuration when viewed from above. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1, and schematically shows the arrangement relationship of the battery module 10 and its peripheral configuration.

A battery pack 1 includes a battery module 10 including a plurality of battery cells 2 , a cooler 3 , a heat transfer sheet 4 and a smoke exhaust path 7 . The battery pack 1 is a semi-sealed battery pack having a pressure relief valve 8 . The plurality of battery cells 2 are spaced apart from each other in a predetermined direction (for example, the left-right direction in FIG. 4), and are arranged so that their side surfaces face each other. A spacer material may be arranged between adjacent battery cells 2 .

A cell safety valve 2A is provided at the bottom of the battery cell 2 . The heat transfer sheet 4 is in contact with at least part of the bottom surface of the battery cell 2 (the surface on which the cell safety valve 2A is provided). The heat transfer sheet 4 has a notch 4A. The position of the notch 4A corresponds to the position of the cell safety valve 2A.

The cooler 3 contacts the surface on which the cell safety valve 2A is provided through the heat transfer sheet 4 . Cooler 3 extends below battery cell 2 . Coolant flows through the cooler 3 . Cooler 3 cools battery cell 2 . Cooler 3 has partition 5 as a part thereof. The partition wall 5 is configured to separate a space in which the battery cells 2 exist from a space in which the battery cells 2 do not exist. The partition wall 5 has a fragile portion 5A that is melted by receiving heat or perforated by receiving pressure. The weakened portion 5A corresponds to the positions of the cell safety valve 2A and the notch 4A of the heat transfer sheet 4. As shown in FIG. The fragile portion 5A is made of resin.

Gas discharged from the battery cells 2 flows through the smoke exhaust path 7 . At least part of the cooler 3 is provided within the smoke exhaust path 7 .

(action and effect)
When the battery cell becomes hot, hot gas can be exhausted from the cell safety valve. If no special countermeasures are taken, the gas and spatter discharged from the battery cells pass through the smoke exhaust path while still at a high temperature, and heat the adjacent battery cells. When the temperature of adjacent battery cells becomes high, chain emission may occur, in which high-temperature gas is generated from the battery cells. When high-temperature gas is discharged from the battery cells, the case of the battery pack may be punctured or the battery pack may be sealed out. After that, the gas and spatter, while still at a high temperature, can be discharged outside the battery pack through a hole made in the case of the battery pack, a sealed-out portion of the battery pack, or a pressure release valve.

These problems may occur because the flue gas passage through which gas and spatter pass is not at a low temperature, and the flue gas passage is not isolated from the battery cells.

In the battery pack 1 of the embodiment, at least part of the cooler 3 is provided in the smoke exhaust path 7, so that the heat of the gas discharged from the battery cells 2 can be cooled.

The high-temperature gas is first discharged from the cell safety valve 2A of the battery cell 2 to the smoke exhaust path 7, as indicated by arrows 21 in FIGS. 1 and 4, for example. At this time, the fragile portion 5A is melted by the heat of the high-temperature gas, or the fragile portion 5A is perforated by the pressure from the gas.

The gas then passes through flue path 7, for example as shown by arrows 22a, 22b and 22c in FIG. 1 and arrows 22d and 22e in FIG. The gas flows along the side of cooler 3 provided in flue gas path 7 . Therefore, in the embodiment shown in FIG. 1, the gas temperature gradually decreases as the gas flows in the order of arrows 22a, 22b, and 22c. Also in the embodiment shown in FIG. 4, the temperature of the gas at the positions indicated by arrows 22d and 22e is lower than the temperature of the gas at the position indicated by arrow 21. FIG. The gas whose temperature has been lowered is discharged from the battery pack 1 through the pressure release valve 8 as indicated by arrow 23 in FIG. 1, for example.

In the battery pack 1 of the embodiment, at least part of the cooler 3 is provided in the smoke exhaust path 7, so that the cooler 3 cools the high-temperature gas containing the spatter in the smoke exhaust path 7, thereby It becomes possible to lower the temperature of the gas when it flows out of the pack 1 . In other words, in the battery pack 1 of the embodiment, the flue gas passage through which the gas and the spatter pass is at a low temperature. . Furthermore, in the battery pack 1 of the embodiment, since the heat of the gas discharged from the cell safety valve 2A is suppressed from being transferred to other battery cells as it is, it is possible to prevent chain smoke generation, and eventually the case of the battery pack 1 can be prevented. perforation and seal-out can be suppressed.

In the battery pack 1 of the embodiment, the space where the battery cells 2 exist and the space where the battery cells 2 do not exist are separated from each other by the partition walls 5 , and the space where the battery cells 2 do not exist becomes the smoke exhaust path 7 . This structure isolates the smoke exhaust path 7 from the battery cell 2 . By isolating the smoke exhaust path 7 and the battery cell 2 from each other, when the high temperature gas discharged from the battery cell 2 passes through the smoke exhaust path 7, the adjacent battery cell 2 is heated by the high temperature gas. can be suppressed.

In battery pack 1 of the embodiment, heat transfer sheet 4 has gaps 4B between adjacent notches 4A. The gap 4</b>B suppresses the heat of the gas discharged from the cell safety valve 2</b>A of the battery cell 2 from being transmitted to the adjacent battery cell 2 . The gap 4B can prevent the adjacent battery cells 2 from being directly hit by the high-temperature gas, and thus can prevent the battery cells 2 from receiving heat.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to include all changes within the meaning and range of equivalents to the claims.

REFERENCE SIGNS LIST 1 battery pack 2 battery cell 2A cell safety valve 3 cooler 4 heat transfer sheet 4B interval 5 partition wall 5A fragile portion 7 smoke exhaust path 8 pressure release valve 10 battery module 21, 22a, 22b , 22c, 22d, 22e, 23 arrows.

Claims (1)

a battery pack,
a battery module including a plurality of battery cells;
a cooler that cools the battery cell;
a smoke exhaust path through which gas discharged from the battery cell flows,
At least part of the cooler is provided in the smoke exhaust path ,
The cooler has a partition as a component of the cooler, and the partition divides the interior of the battery pack into a space where the battery cells exist and a space where the battery cells do not exist. are formed separately from each other, the smoke exhaust path is located in a space where the battery cell does not exist,
The battery cell has a surface provided with a cell safety valve,
The battery pack further comprises a heat transfer sheet, the heat transfer sheet being in contact with at least part of the surface of the battery cell on which the cell safety valve is provided,
the partition wall of the cooler is in contact with the surface of the battery cell provided with the cell safety valve via the heat transfer sheet;
The heat transfer sheet has a notch, the position of the notch corresponds to the position of the cell safety valve,
The partition wall has a fragile portion that melts by receiving heat or opens a hole by receiving pressure, and in a state where the hole is not opened, the surface of the battery cell on which the cell safety valve is provided is not exposed to the smoke evacuation path,
The fragile portion corresponds to the position of the notch of the cell safety valve and the heat transfer sheet,
The battery pack, wherein the gas discharged from the cell safety valve flows into the smoke exhaust path through the notch and the hole opened in the fragile portion.

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