Battery pack

Abstract

To provide a battery pack capable of suppressing the accumulation of gas within a battery pack.SOLUTION: A battery pack includes a plurality of battery cells, a case for housing the battery cells, a first gas exhaust valve provided in the battery cells, and a second gas exhaust valve provided in the case, wherein the first gas exhaust valve opens when the pressure inside the battery cells reaches or exceeds a predetermined pressure during charging, and the second gas exhaust valve opens during discharging or when the battery is at rest.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a battery pack in which an on-off valve opens when the internal pressure reaches or exceeds a predetermined pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-073211 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology disclosed in Patent Document 1, when gas is discharged from a battery pack in which multiple battery cells are mounted, the gas remains inside the battery pack, and therefore there is room for improvement.

[0005] The present disclosure has been made in consideration of the above, and has an object to provide a battery pack that can suppress the retention of gas within the battery pack. [Means for solving the problem]

[0006] The battery pack according to the present disclosure comprises a plurality of battery cells, a case for housing the battery cells, a first gas exhaust valve provided in the battery cells, and a second gas exhaust valve provided in the case, the first gas exhaust valve being opened when the pressure inside the battery cells reaches or exceeds a predetermined pressure during charging, and the second gas exhaust valve being opened during discharging or when at rest. Effect of the Invention

[0007] According to the present disclosure, by discharging gas from within a battery pack during discharging or resting, it is possible to prevent gas from being released suddenly while suppressing gas retention within the battery pack. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a battery pack according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A battery pack according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components in the following embodiments include those that are replaceable and easy for a person skilled in the art, or those that are substantially the same.

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

[0011] 1 is a schematic diagram showing an example of the configuration of a battery pack according to an embodiment. The battery pack 1 includes a case 11 and a plurality of battery cells 13. Although not shown in the figure, the battery pack 1 is provided with sensors for measuring the internal pressure (internal pressure) of the battery cells 13, and a control means (e.g., an ECU) for controlling the opening and closing of the gas release valves 12 and 14.

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

[0013] The gas exhaust valve 12 is a valve for exchanging air inside the case 11. This gas exhaust valve 12 is in an open state when the battery cell 13 is discharging or at rest. The gas exhaust valve 12 is in a closed state when the battery cell 13 is charging. Note that while FIG. 1 shows a case where one circular gas exhaust valve 12 is provided on the top of the case 11, the shape, position, number, etc. of the gas exhaust valve 12 are not particularly limited.

[0014] The battery cells 13 are, for example, lithium ion secondary batteries. The battery cells 13 include, for example, lithium polymer batteries that use polymer gel as an electrolyte. The battery cells 13 are stacked in a predetermined direction inside the case 11. The battery cells 13 are also provided with a gas exhaust valve (first gas exhaust valve) 14.

[0015] The gas exhaust valve 14 is a valve for exhausting gas generated inside the battery cell 13. This gas exhaust valve 14 opens when the pressure inside the battery cell 13 reaches a predetermined pressure (the internal pressure of the battery cell 13 is a reference value) or higher when the battery cell 13 is being charged. The gas exhaust valve 14 closes when the battery cell 13 is being discharged or is at rest. Note that while FIG. 1 shows a case where one circular gas exhaust valve 14 is provided on the top of the battery cell 13, the shape, position, number, etc. of the gas exhaust valve 14 are not particularly limited.

[0016] In the battery pack 1 having such a configuration, for example, when the internal pressure of the battery cell 13 becomes equal to or higher than a predetermined pressure during charging, the gas release valve 14 of the battery cell 13 is opened and the gas inside the battery cell 13 is released into the case 11. On the other hand, when the gas release valve 14 of the battery cell 13 is opened during charging, the gas release valve 12 of the case 11 is closed. This makes it possible to prevent gas from being suddenly (largely) released from the gas release valve 12.

[0017] Also, when the gas release valve 14 of the battery cell 13 is closed other than during charging, i.e. during discharging or rest, the gas release valve 12 of the case 11 is opened. This allows the internal air in the case 11 to be slowly exchanged with the external air. That is, during normal times when gas is not being released from the battery cell 13, the gas release valve 12 exchanges the internal air with the external air, for example, like breathing.

[0018] According to the battery pack of the embodiment described above, by discharging gas from within the battery pack 1 during discharging or resting, it is possible to prevent the gas from being released suddenly while suppressing the accumulation of gas within the battery pack 1.

[0019] That is, in the battery pack 1, gas exhaust valves 14 for exhausting gas generated inside the battery cells 13 are attached to the battery cells 13 to exhaust the gas. In addition, a gas exhaust valve 12 is also attached to the case 11 to exchange air inside the case 11. This gas exhaust valve 12 constantly exchanges outside air with inside air, just like breathing.

[0020] Then, if the internal pressure of the battery cell 13 becomes equal to or exceeds a reference value, the gas release valve 14 of the battery cell 13 is opened during charging to release the gas. At this time, the gas release valve 14 is opened only for the battery cell 13 whose internal pressure has become high inside the case 11. The gas release valve 14 of the battery cell 13 whose internal pressure does not meet the reference value is not opened because there is no need to open it. Also, the gas release valve 14 is opened during charging because the internal pressure of the battery cell 13 is higher during charging, making it easier for gas to escape.

[0021] As described above, the gas exhaust valve 12 attached to the case 11 constantly exchanges outside air with inside air like breathing, but if the gas exhaust valve 14 of the battery cell 13 is opened during charging, the gas exhaust valve 12 is always closed. Closing the gas exhaust valve 12 in this way prevents a large amount of gas from being exhausted from the gas exhaust valve 12 (a strong gas ejection force).

[0022] Furthermore, when the gas release valve 14 of the battery cell 13 is closed (during discharging or resting), the gas release valve 12 of the case 11 returns to its original state, exchanging the inside air with the outside air. In this way, by releasing gas through the gas release valve 12 of the case 11 before the gas release valve 14 of the battery cell 13 opens, the battery cell 13 can be used safely and for a long period of time. Furthermore, by releasing the gas accumulated inside the case 11 little by little through the gas release valve 12 of the case 11, there is no need to worry about accumulated gas when performing maintenance on the battery pack 1.

[0023] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0024] 1 Battery pack 11 Cases 12 Gas exhaust valve (second gas exhaust valve) 13 Battery Cell 14 Gas exhaust valve (first gas exhaust valve)

Claims

[Claim 1] A plurality of battery cells; a case that houses the battery cell; a first gas exhaust valve provided in the battery cell; A second gas exhaust valve provided in the case; Equipped with the first gas release valve opens when the pressure inside the battery cell reaches or exceeds a predetermined pressure during charging; The second gas exhaust valve is in an open state during discharge or during rest. Battery pack.

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