JP2022014716A - Battery module - Google Patents

Abstract

To prevent an event from being propagated to another cell when a predetermined event occurs to cells constituting a battery pack.SOLUTION: A battery module 100 disclosed herein comprises a battery pack 10 composed of a plurality of cells 12 aligned in a predetermined direction, an accommodating unit 50 for accommodating inert gas that can be supplied to the battery pack, and a detection unit 61 for detecting an event when a predetermined event occurs to any of the cells in the battery pack. The accommodating unit is configured so that the inert gas is supplied to the cell to which the event has occurred. The inert gas is configured to be supplied from the side opposite to a position where the event has occurred, with a position of the center of gravity of the cell to which the event has occurred as a reference.SELECTED DRAWING: Figure 2

Description

The present invention relates to a battery module having a mechanism for supplying an inert gas to the target battery.

A battery that can be charged and discharged, such as a lithium ion secondary battery, is used as a cell, and an assembled battery including a plurality of the cells is preferably used as a power source for mounting on a vehicle. In such an assembled battery, for example, a plurality of square cells are arranged so as to be adjacent to each other along a predetermined arrangement direction, and each cell is restrained while applying a predetermined restraining load along the arrangement direction. Later, it is constructed by electrically connecting the electrode terminals (positive electrode terminal and negative electrode terminal) of each cell with a bus bar.
If the cells that make up the assembled battery are overcharged or the electrode body is damaged, excessive heat generation (overheating) may occur, and the overheating that occurs in some cells is the other unit. There is a risk that chain heat generation will proceed, which propagates to the batteries and heats the cells to each other.

In order to prevent such heat generation, for example, in Patent Document 1, the fire extinguishing agent is sprayed from the ceiling surface of the assembled battery so that the flow of the fire extinguishing agent surrounds the area where the plurality of secondary batteries are arranged, and the fire extinguishing agent is ignited. A method of extinguishing a fire of a rechargeable battery is disclosed. Further, Patent Document 2 discloses that a heat insulating sheet is arranged between the cells in order to suppress heat propagation.

Japanese Unexamined Patent Publication No. 2016-73328 Japanese Unexamined Patent Publication No. 2019-83150

However, when the heat propagation speed is high, the injection of the fire extinguishing agent cannot catch up and the heat generation cannot be controlled. Further, when high temperature gas is generated in any of the cells constituting the assembled battery, it is not enough to prevent the chain of heat generation only by insulating the cells, and the heat propagation is suppressed more effectively. A mechanism is required.

The present invention has been made in view of this point, and provides a battery module that suitably suppresses the propagation of an event to another cell when an event occurs in the cell constituting the assembled battery. The purpose is to do.
In the present specification, the "predetermined event (or simply" event ")" refers to the occurrence of an abnormality occurring in a cell that can generate an abnormal state different from the normal usage state of the battery. Although not limited to these, heat generation due to overcharging or short circuit of the cell, generation of gas due to the reaction of the electrolyte inside the cell, increase in pressure inside the cell, etc. are described here. Is given as an example of.

The battery module provided by the present invention includes an assembled battery in which a plurality of cells are arranged in a predetermined direction, an accommodating portion for accommodating an inert gas that can be supplied toward the assembled battery, and the above-mentioned assembly. It is provided with a detection unit that detects a predetermined event when a predetermined event occurs in any of the batteries. Here, the accommodating portion is configured to supply the inert gas to the cell in which the event has occurred, and the inert gas is the cell in which the event has occurred. It is configured to be supplied from the side opposite to the position where the event occurred with respect to the position of the center of gravity.

According to this configuration, by supplying the inert gas from the direction opposite to the event occurrence direction with reference to the center of the battery (position of the center of gravity), the difference in the inert gas due to oxygen consumption at the time of the event occurrence and high temperature gas injection. It is possible to quickly reach the place where the event occurs by riding on the airflow generated by pressure. As a result, it is possible to suppress the generation of high-temperature gas due to the occurrence of an event and suitably prevent heat chaining to the adjacent cell.

It is a perspective view which shows an example of the assembled battery which constitutes an electronic module. It is a side view which shows typically the battery module which concerns on one Embodiment. It is a perspective view which shows an example of the positional relationship between the event occurrence position and the inert gas supply position in the cell which concerns on one Embodiment. It is a side view which shows typically the battery module which concerns on one Embodiment.

Hereinafter, a preferred embodiment according to the present invention will be described with reference to the drawings. Matters other than those specifically mentioned in the present specification and necessary for the implementation of the technique disclosed herein can be grasped as design matters of a person skilled in the art based on the prior art in the art. The battery module disclosed herein can be prepared and used based on the contents disclosed in the present specification and the common general technical knowledge in the art. In the following drawings, members / parts having the same function are designated by the same reference numerals, and duplicate explanations may be omitted or simplified.

As the cell constituting the battery module disclosed here, a commonly used secondary battery capable of repeated charging and discharging can be used, and a lithium ion secondary battery can be typically used.
As used herein, the term "secondary battery" generally refers to a power storage device that can be repeatedly charged and discharged, and is a term that includes a so-called storage battery and a power storage element such as an electric double layer capacitor. Further, in the present specification, the "lithium ion secondary battery" refers to a secondary battery that uses lithium ions as a charge carrier and realizes charge / discharge by the transfer of charges accompanying the lithium ions between the positive and negative electrodes.
As the lithium ion secondary battery, for example, an all-solid-state battery in which the electrolyte is composed of a solid electrolyte, or a non-aqueous electrolyte lithium-ion secondary battery using a non-aqueous electrolyte as the electrolyte is used. As an electrode body used for a non-aqueous electrolyte lithium ion secondary battery, typically, a wound electrode body in which a sheet-shaped positive electrode and a negative electrode are wound, or a laminated electrode body in which a sheet-shaped positive electrode and a negative electrode are laminated. Is used.

FIG. 1 is a perspective view showing the configuration of an assembled battery constituting the battery module according to the embodiment. As shown in FIG. 1, the cell 12 is provided with a positive electrode terminal 15 and a negative electrode terminal 16 on the upper portion of the cell case 14, and these electrode terminals are electrically connected to the adjacent cell 12 via the bus bar 17. It is connected to the. A safety valve 13 for venting gas generated inside the container is provided on the upper part of the battery case 14. The cell 12 is not limited to the square type as shown in FIG. 1, and may be, for example, a cylindrical type or a laminated type.

The cells 12 are arranged via the spacer 11. A pair of end plates 18 and 19 are arranged further outside the spacer 11 arranged on the outermost side. Further, a length adjusting member 40 for adjusting the length of the assembled battery 10 is sandwiched between the spacer 11 and the end plate 18 arranged on the outside of one side of the cell group. Then, these are restrained by the tightening beam material 21 attached so as to bridge the end plates 18 and 19, and the end portion of the tightening beam material 21 is tightened and fixed by the screw 22.

FIG. 2 is a side view schematically showing the battery module 100 according to the embodiment. The battery module 100 accommodates an assembled battery 10 in which a plurality of square cell cells 12 are arranged in a predetermined direction via a spacer 11 and an inert gas that can be supplied toward the assembled battery 10. It includes 50 and a detection unit 61 that detects an event when an event occurs in any of the cells 12 of the assembled battery 10.

The detection unit 61 includes, for example, a sensor for detecting the occurrence of an event such as a temperature sensor such as a thermocouple, a gas component detection sensor, and a pressure sensor (hereinafter, also simply referred to as “sensor”), and houses the assembled battery 10. It is arranged on the inner wall of the battery case 60. The detection unit 61 is arranged on the ceiling surface (that is, the surface facing the safety valve 13) of the inner wall of the assembled battery case 60. The sensor may be a contact type or a non-contact type that contacts the cell 12.

The accommodating section 50 includes a release valve 51 that releases an inert gas when an event occurs. As the inert gas, nitrogen, argon or the like can be used. Here, the accommodating portion 50 is provided on the bottom surface of the assembled battery case 60 (that is, the surface of the assembled battery case 60 facing the detection unit 61). The internal pressure of the accommodating portion 50 is higher than the internal pressure of the assembled battery case 60 so that the inert gas is spontaneously released into the assembled battery case 60 when the release valve 51 is released.

FIG. 3 is a perspective view showing an example of the positional relationship between the event occurrence position A and the release valve 51E opened when the event occurs when an event occurs in the cell constituting the battery module according to the embodiment. be. In order to prevent the battery from exploding when the internal pressure rises due to the occurrence of an abnormality in the cell 12 on the upper part (the side where the terminal is arranged) of the cell 12 constituting the battery module shown in FIG. Safety valve 13 is provided. When an event occurs in the cell 12 provided with the safety valve 13, the event occurrence position A coincides with the position of the safety valve 13.

The discharge valve 51 provided in the accommodating portion 50 has, for example, an intersection of a straight line from the position of the release valve 13 that can be the event occurrence position A toward the position O of the center of gravity of the cell 12 and the bottom surface of the assembled battery case 60 as B. When this is done, the battery case 60 may be arranged at a position on the bottom surface of the assembled battery case 60 so that the angle formed by the line segment BO is equal to or less than a predetermined angle θ. The angle θ is usually 90 degrees or less, preferably 60 degrees or less, more preferably 45 degrees or less, for example, 30 degrees or less.
The discharge valve 51 may be provided for each of the cell cells 12, or may be provided intermittently.

Although not shown, the electronic module 100 according to the present embodiment includes a control unit that controls the opening and closing of the release valve 51. The control unit determines that an event has occurred in any of the cell cells 12 by the sensor provided in the detection unit 61, and the cell cell 12A in which the event has occurred from the position of the detection unit 61D that has detected the event. It is equipped with a detection means to detect. Further, the control unit is provided with an opening means for opening the release valve 51E corresponding to the cell 12A in which the event has occurred. The detecting means and the opening means are electrically connected. When the detecting means detects the occurrence of an event, the information is transmitted to the opening means. That is, when the detecting means detects the occurrence of an event in the cell 12A, the opening means opens the release valve 51E corresponding to the cell 12A. As a result, the inert gas is released from the opposite side with respect to the position of the center of gravity of the cell 12A with respect to the event occurrence position A, and heat propagation can be suitably suppressed.

As a specific example, a case where a thermocouple is used as a sensor provided in the detection unit 61 will be described below as an example. First, the temperature of the cell 12 is detected by the thermocouple provided in the detection unit 61. Next, it is determined whether or not the detected temperature of the cell 12 is equal to or higher than a predetermined threshold value. If the detected temperature of the cell 12 is not equal to or higher than a predetermined threshold value, the process returns to the process of detecting the temperature of the cell 12. When the detected temperature of the cell 12 is equal to or higher than a predetermined threshold value, the cell 12A in which the event occurred from the position of the thermocouple (detection section 61D) that detected the temperature equal to or higher than the threshold value in the detection unit 61. (Detection means). Then, the information of the cell 12A is transmitted to the opening means, and the release valve 51E corresponding to the cell 12A is opened.

FIG. 4 is a side view schematically showing the battery module 100 according to the embodiment. The battery module 100 accommodates an assembled battery 10 in which a plurality of laminated cell cells 12 are arranged in a predetermined direction via a spacer 11 and an inert gas that can be supplied toward the assembled battery 10. It includes 50 and a detection unit 61 that detects an event when an event occurs in any of the cells 12 of the assembled battery 10. Since the laminated cell 12 is not provided with the safety valve, the event occurrence position A can be any position of the seal portion (not shown) of the cell 12.

The detection unit 61 includes the above-mentioned sensor and is arranged on the inner wall of the assembled battery case 60 for accommodating the assembled battery 10. In order to detect the event occurrence position set A when an event occurs in the cell 12, a plurality of detection units 61 are provided in a battery case for each cell 12 so as to surround the seal portion of each cell 12. It is provided on the inner wall of 60.

The accommodating portion 50 includes a release valve 51 that releases the above-mentioned inert gas when an event occurs. Here, in the accommodating portion 50 and the release valve 51, the released inert gas is opposite to the event occurrence position A with respect to the event occurrence position A with respect to the center of gravity position O of the cell 12A in which the event occurs. It is arranged to be supplied from the side. That is, the assembled battery case 60 is provided so as to surround the seal portion of each of the cell cells 12.
A plurality of discharge valves 51 provided in the accommodating portion 50 may be arranged for each of the cell 12 so as to surround the seal portion of the cell 12.

Although not shown, the electronic module 100 according to the present embodiment includes a control unit that controls the opening and closing of the release valve 51. The control unit includes a detection means for detecting an event generated in the cell 12 by a sensor provided in the detection unit 61, and an opening means for opening the release valve 51E corresponding to the cell 12A in which the event has occurred. The detecting means and the opening means are electrically connected. When the detecting means detects the occurrence of an event, the information is transmitted to the opening means. Based on such information, the opening means opens the release valve 51E so that the inert gas is discharged from the opposite side of the center of gravity position O of the cell 12A with respect to the event occurrence position A.

When the intersection of the straight line from the event occurrence position A to the center of gravity position O of the cell 12A and the inner wall of the assembled battery case 60 is B, the angle formed by the line segment BO is equal to or less than a predetermined angle θ. The release valve 51 arranged at the position is opened. The angle θ is usually 90 degrees or less, preferably 60 degrees or less, more preferably 45 degrees or less, for example, 30 degrees or less.

As a specific example, a case where a thermocouple is used as a sensor provided in the detection unit 61 will be described below as an example. First, the temperature of the cell 12 is detected by the thermocouple provided in the detection unit 61. Next, it is determined whether or not the detected temperature of the cell 12 is equal to or higher than a predetermined threshold value. If the detected temperature of the cell 12 is not equal to or higher than a predetermined threshold value, the process returns to the process of detecting the temperature of the cell 12. When the detected temperature of the cell 12 is equal to or higher than a predetermined threshold value, the cell 12A in which the event occurred from the position of the thermocouple (detection section 61D) that detected the temperature equal to or higher than the threshold value in the detection unit 61. And the event occurrence position A is estimated (detection means). Then, the information of the cell 12A and the event occurrence position A is transmitted to the opening means, and the inert gas is discharged from the opposite side of the cell 12A from the center of gravity position O of the cell 12A with respect to the event occurrence position A of the cell 12A. As described above, the release valve 51E is selected from the release valve 51 and is opened.

When a predetermined event occurs in any of the cells constituting the assembled battery, the battery module configured as described above is based on the position of the center of gravity of the cell in which the event occurs with respect to the event occurrence position. It is configured so that the inert gas is supplied from the opposite side. According to such a battery module, the inert gas can be supplied to the event occurrence position more quickly than the conventionally used inert gas supply mechanism, and the chain of heat generation can be suitably suppressed. Can be done.

The battery module disclosed here is not limited to the above-described embodiment, and various configurations can be changed. For example, the number of cell cells constituting the assembled battery is not particularly limited. Further, the number and arrangement of the sensors constituting the detection unit and the discharge valves provided in the accommodating unit are appropriately set according to the battery configuration.

The battery module disclosed herein can be used for various purposes. For example, it can be suitably used as a power source (driving power source) for a motor mounted on a vehicle. The type of vehicle is not particularly limited, but typically examples thereof include automobiles, for example, plug-in hybrid vehicles (PHVs), hybrid vehicles (HVs), electric vehicles (EVs), and the like.

10 Battery 11 Spacer 12 Single battery 12A Single battery in which an event occurred 13 Safety valve 14 Single battery case 15 Positive terminal 16 Negative terminal 17 Bus bar 18 End plate 19 End plate 21 Tightening beam material 22 Screw 40 Length adjusting member 50 Accommodating part 51 Discharge valve 51E Discharge valve that is opened when an event occurs 60 sets Battery case 61 Detection unit 61D Detection unit that detects the occurrence of an event 100 Battery module A Event occurrence position in the cell O Position of the center of gravity of the cell

Claims (1)

A predetermined battery in an assembled battery composed of a plurality of cells arranged in a predetermined direction, an accommodating portion for accommodating an inert gas that can be supplied to the assembled battery, and any of the cells in the assembled battery. It is equipped with a detection unit that detects an event when it occurs.
Here, the accommodating portion is configured to supply the inert gas to the cell cell in which the event has occurred.
Moreover, the inert gas is configured to be supplied from the side opposite to the position where the event occurred, with reference to the position of the center of gravity of the cell in which the event occurred.
Battery module.

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