Battery pack

Abstract

The utility model provides a battery pack capable of inhibiting gas from being retained in the battery pack. The battery pack includes a plurality of battery cells, a case housing the battery cells, a first gas discharge valve provided in the battery cells, and a second gas discharge valve provided in the case, the first gas discharge valve being in an open state when the pressure in the battery cells is equal to or greater than a predetermined pressure during charging, and the second gas discharge valve being in a closed state when the battery cells are discharged or stopped. The second gas discharge valve is in an open state.

Description

Technical Field

[0001] The present disclosure relates to a battery pack. Background Art

[0002] Patent Document 1 discloses a battery pack in which an on-off valve is opened when the internal pressure is equal to or greater than a predetermined pressure.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-073211.

[0004] In the technology disclosed in Patent Document 1, when gas is exhausted from a battery pack equipped with a plurality of battery cells, the gas accumulates in the battery pack, and thus there is room for improvement. Utility Model Content

[0005] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a battery pack capable of suppressing gas from stagnation in the battery pack.

[0006] The battery pack involved in the present disclosure comprises: a plurality of battery cells; a shell for accommodating the battery cells; a first gas discharge valve provided on the battery cells; and a second gas discharge valve provided on the shell. During charging, if the pressure in the battery cells is equal to or greater than a predetermined pressure, the first gas discharge valve becomes open, and during discharging or rest, the second gas discharge valve becomes open.

[0007] According to the present disclosure, by discharging the gas in the battery pack during discharge or rest, it is possible to prevent the gas from being rapidly released and suppress the gas from being retained in the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram showing an example of the configuration of a battery pack according to the embodiment. DETAILED DESCRIPTION

[0009] The battery pack according to the embodiment of the present disclosure will be described with reference to the accompanying drawings. Components in the following embodiments include those that can be easily replaced by those skilled in the art or are substantially the same.

[0010] The following reference Figure 1 The configuration of a battery pack according to the embodiment will be described. The battery pack according to the embodiment can be used as a battery for, for example, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV).

[0011] Figure 1 This is a schematic diagram illustrating an example of the configuration of a battery pack according to an embodiment. The battery pack 1 includes a housing 11 and a plurality of battery cells 13. Although not shown in this figure, the battery pack 1 is also equipped with sensors for measuring the internal pressure of the battery cells 13 (hereinafter referred to as "internal pressure") and a control unit (e.g., an ECU) for controlling the opening and closing of the gas discharge valves 12 and 14.

[0012] The housing 11 houses a plurality of battery cells 13 . The housing 11 is provided with a gas discharge valve (second gas discharge valve) 12 .

[0013] The gas discharge valve 12 is a valve for exchanging the air inside the housing 11. The gas discharge valve 12 is opened when the battery cell 13 is being discharged or stopped. The gas discharge valve 12 is closed when the battery cell 13 is being charged. Figure 1 1 shows a case where one circular gas discharge valve 12 is provided on the upper portion of the housing 11 , but the shape, position, number, etc. of the gas discharge valve 12 are not particularly limited.

[0014] The battery cells 13 are, for example, lithium-ion secondary batteries. These battery cells 13 also include, for example, lithium polymer batteries using a polymer gel as an electrolyte. The battery cells 13 are stacked in a predetermined direction within the housing 11. Furthermore, the battery cells 13 are provided with gas discharge valves (first gas discharge valves) 14.

[0015] The gas discharge valve 14 is a valve for discharging gas generated inside the battery cell 13. When the battery cell 13 is charged, if the pressure inside the battery cell 13 is equal to or greater than a predetermined pressure (the internal pressure of the battery cell 13 is a reference value), the gas discharge valve 14 is opened. On the other hand, the gas discharge valve 14 is closed when the battery cell 13 is discharged or not. Figure 1 1 and 2 show a case where one circular gas discharge valve 14 is provided on the upper portion of the battery cell 13 , but the shape, position, number, etc. of the gas discharge valve 14 are not particularly limited.

[0016] In the battery pack 1 having the above configuration, for example, when the internal pressure of a battery cell 13 is equal to or greater than a predetermined pressure during charging, the gas discharge valve 14 of the battery cell 13 opens, and the gas within the battery cell 13 is discharged into the housing 11. On the other hand, when the gas discharge valve 14 of the battery cell 13 is open during charging, the gas discharge valve 12 of the housing 11 is closed. This prevents the rapid (large-scale) release of gas from the gas discharge valve 12.

[0017] Furthermore, when the gas discharge valve 14 of the battery cell 13 is closed (i.e., during discharge or rest), the gas discharge valve 12 of the housing 11 is open. This allows for a gradual exchange of air between the inside and outside air within the housing 11. In other words, under normal circumstances, when the gas within the battery cell 13 is not being discharged, the gas discharge valve 12 allows for an exchange of air between the inside and outside air, similar to breathing.

[0018] According to the battery pack according to the embodiment described above, by discharging the gas in the battery pack 1 during discharge or rest, it is possible to prevent the gas from being rapidly released and suppress the gas from being retained in the battery pack 1 .

[0019] In other words, in the battery pack 1, a gas discharge valve 14 is attached to the battery cell 13 to discharge the gas generated inside the battery cell 13. Furthermore, a gas discharge valve 12 is also attached to the housing 11 to exchange the air inside the housing 11. This gas discharge valve 12 constantly exchanges the outside air with the inside air, just like breathing.

[0020] Furthermore, when the internal pressure of a battery cell 13 is equal to or greater than a reference value, the gas discharge valve 14 of the battery cell 13 opens during charging to release gas. At this time, the gas discharge valve 14 opens only in the battery cell 13 where the internal pressure within the housing 11 is high. The gas discharge valve 14 of the battery cell 13 where the internal pressure is below the reference value does not need to open and therefore does not open. The gas discharge valve 14 opens during charging because the internal pressure of the battery cell 13 rises during charging, facilitating gas discharge.

[0021] As described above, the gas discharge valve 12 attached to the housing 11 constantly exchanges air between the outside and inside, like breathing. However, during charging, if the gas discharge valve 14 of the battery cell 13 is open, the gas discharge valve 12 is always closed. Closing the gas discharge valve 12 in this way prevents large amounts of gas from being discharged from the gas discharge valve 12 (which could increase the momentum of the gas discharge).

[0022] Furthermore, when the gas discharge valve 14 of the battery cell 13 is closed (during discharge or rest), the gas discharge valve 12 of the housing 11 returns to its original position, exchanging internal and external air. This allows for safe and long-term use of the battery cell 13 by venting gas from the housing 11's gas discharge valve 12 before the battery cell 13's gas discharge valve 14 opens. Furthermore, by gradually venting gas accumulated within the housing 11 through the housing 11's gas discharge valve 12, there is no need to worry about trapped gas during maintenance of the battery pack 1.

[0023] Further effects and modifications will readily occur to those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Therefore, various modifications may be made without departing from the spirit or scope of the general utility model concept as defined by the appended claims and their equivalents.

Claims

1. A battery pack, characterized in that: have: multiple battery cells; a housing for accommodating the battery unit; A first gas exhaust valve provided on the battery cell; and A second gas exhaust valve is provided on the housing, During charging, if the pressure in the battery cell is equal to or greater than a predetermined pressure, the first gas discharge valve is opened. During discharge or rest, the second gas discharge valve is in an open state.

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