KR20240033919A - Battery module and battery pack including the same - Google Patents

Abstract

A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked; a module frame accommodating the battery cell stack; and an automatic fire extinguishing member formed on the module frame, wherein the automatic fire extinguishing member includes: a fire extinguishing body portion that accommodates fire extinguishing liquid; A digestive juice discharge portion formed on one side of the fire extinguishing main body and through which the digestive fluid is discharged; And a communication part located inside the digestive juice discharge part, wherein a first valve is formed between the fire extinguishing main body and the communicating part, and a second valve is formed between the fire extinguishing main body and the digestive juice discharge part, An auxiliary valve is formed in the communication part.

Description

Battery module and battery pack including the same {BATTERY MODULE AND BATTERY PACK INCLUDING THE SAME}

The present invention relates to a battery module and a battery pack containing the same, and more specifically, to a battery module with improved safety and a battery pack containing the same.

As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting much attention as an energy source for not only mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

While small mobile devices use one or two or three battery cells per device, mid- to large-sized devices such as automobiles require high output and large capacity. Therefore, medium-to-large battery modules in which multiple battery cells are electrically connected are used.

Since it is desirable for medium to large-sized battery modules to be manufactured in as small a size and weight as possible, rectangular batteries and pouch-type batteries that can be stacked with high integration and have a small weight-to-capacity battery are mainly used as battery cells for medium-to-large battery modules. These battery modules have a structure in which multiple cell assemblies including a plurality of unit battery cells are connected in series to obtain high output. Additionally, the battery cell is capable of repeated charging and discharging through electrochemical reactions between its components, including positive and negative current collectors, separators, active materials, and electrolyte solutions.

Meanwhile, as the need for large-capacity structures has increased recently, including use as an energy storage source, there has been a demand for a battery pack with a multi-module structure in which multiple battery modules are connected in series and/or parallel and the battery modules are aggregated. is increasing.

Additionally, when configuring a battery pack by connecting a plurality of battery cells in series/parallel, a battery module consisting of at least one battery cell is first constructed, and other components are added using this at least one battery module to pack the battery pack. This method of configuring is common.

In general, when the temperature of a secondary battery rises higher than an appropriate temperature, the performance of the secondary battery may deteriorate, and in severe cases, there is a risk of explosion or ignition. In particular, the temperature of a battery module or battery pack having multiple secondary batteries, that is, battery cells, can increase rapidly and severely due to the addition of heat from the multiple battery cells in a small space. In other words, in the case of battery modules with multiple battery cells stacked and battery packs equipped with these battery modules, high output can be achieved, but it is not easy to remove the heat generated from the battery cells during charging and discharging, resulting in explosion. The possibility of ignition increases.

At this time, explosions and flames generated in one battery module may affect other battery modules, resulting in a thermal runaway phenomenon in which flames and fires occur in succession. Additionally, when thermal runaway occurs, the safety of devices equipped with battery modules and battery packs and users using them cannot be secured.

Therefore, there is a need for a fire suppression and prevention structure to prevent high-temperature and high-pressure gas eruption from battery modules and battery packs and chain explosion and thermal runaway phenomenon caused by the high-temperature and high-pressure gas.

The problem to be solved by the present invention is to provide a battery module with improved safety and a battery pack including the same by including a new structure that can prevent fire and explosion by detecting the pressure and temperature inside the battery module.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, and problems not mentioned can be clearly understood by those skilled in the art from this specification and the attached drawings. There will be.

A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked; a module frame accommodating the battery cell stack; and an automatic fire extinguishing member formed on the module frame, wherein the automatic fire extinguishing member includes: a fire extinguishing body portion that accommodates fire extinguishing liquid; A digestive juice discharge portion formed on one side of the fire extinguishing main body and through which the digestive fluid is discharged; And a communication part located inside the digestive juice discharge part, wherein a first valve is formed between the fire extinguishing main body and the communicating part, and a second valve is formed between the fire extinguishing main body and the digestive juice discharge part, An auxiliary valve is formed in the communication part.

A sensing unit may be formed in each of the first valve, the second valve, and the communication unit.

The sensing unit formed on the first valve and the second valve may include a pressure sensor or a strain sensor.

The sensing unit formed in the communication part may include a temperature sensor.

When venting gas is generated from the battery cell, the auxiliary valve, the first valve, and the second valve are sequentially opened, and as the second valve is opened, the digestive juice discharge portion is opened to release the digestive fluid.

The first valve and the second valve may include a weak portion that is relatively thin.

The first valve and the second valve may each be opened at different pressures.

The pressure at which the first valve opens may be lower than the pressure at which the second valve opens.

An opening is formed on one side of the module frame where the automatic fire extinguishing member is formed, and the fire extinguishing liquid discharge part and the communication part may be fitted into the opening.

The battery module may further include a sealing part formed between the fire extinguishing main body and the fire extinguishing liquid discharge part, and the sealing part may fill the space between the opening and the fire extinguishing main body.

The module frame and the automatic fire extinguishing member may be coupled by a fastening member.

A battery pack according to another embodiment of the present invention includes the battery module.

The battery module according to an embodiment of the present invention includes a fire extinguishing member formed on the upper part of the battery module, thereby detecting the pressure and temperature inside the battery module and releasing fire extinguishing substances to prevent thermal runaway and chain explosion of the battery module. can do.

Additionally, by preventing thermal runaway and chain explosion of the battery module, the safety of the battery module and battery pack can be improved and users can be protected.

The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by those skilled in the art from this specification and the attached drawings.

1 is a partially exploded perspective view of a battery module according to an embodiment of the present invention.
Figure 2 is a perspective view showing a battery module assembled from the components of Figure 1.
Figure 3 is a perspective view showing a fire extinguishing member included in a battery module according to an embodiment of the present invention as seen from below.
Figure 4 is a cross-sectional view taken along the cutting line a-a' of Figure 3.
Figure 5 is a conceptual diagram showing the operation method of the fire extinguishing member of Figure 4.
Figure 6 is an enlarged view of part A of Figure 5.
Figure 7 is an enlarged view of part B of Figure 5.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts that are not relevant to the description are omitted, and identical or similar components are assigned the same reference numerals throughout the specification.

In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown. In the drawing, the thickness is enlarged to clearly express various layers and regions. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

Additionally, when a part of a layer, membrane, region, plate, etc. is said to be “on” or “on” another part, this includes not only cases where it is “directly above” another part, but also cases where there is another part in between. . Conversely, when a part is said to be “right on top” of another part, it means that there is no other part in between. In addition, being "on" or "on" a reference part means being located above or below the reference part, and necessarily meaning being located "above" or "on" the direction opposite to gravity. no.

In addition, throughout the specification, when a part is said to "include" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

In addition, throughout the specification, when referring to “on a plane,” this means when the target portion is viewed from above, and when referring to “in cross section,” this means when a cross section of the target portion is cut vertically and viewed from the side.

The first and second terms used in this application may be used to describe various components, but the components should not be limited by the terms. Terms are used only to distinguish one component from another.

Hereinafter, the battery module of the present invention will be described with reference to FIGS. 1 and 2. 1 is a partially exploded perspective view of a battery module according to an embodiment of the present invention. Figure 2 is a perspective view showing a battery module assembled from the components of Figure 1.

Referring to Figures 1 and 2, the battery module 100 according to this embodiment includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked and a module that accommodates the battery cell stack 120. Includes frame 200.

First, the battery cell 110 is preferably a pouch-type battery cell, and may be formed in a rectangular sheet-like structure. However, the type of the battery cell 110 is not limited to this and may be a prismatic battery cell or a cylindrical battery cell.

These battery cells 110 may be composed of a plurality, and the plurality of battery cells 110 are stacked so as to be electrically connected to each other to form the battery cell stack 120. In particular, as shown in FIG. 1, a plurality of battery cells 110 may be stacked.

Meanwhile, the module frame 200 includes a U-shaped frame 300 that is open at the top, front, and rear and covers the lower and both sides of the battery cell stack 120, and an upper part that covers the top of the battery cell stack 120. Includes plate 400. At this time, the U-shaped frame 300 may include a bottom portion supporting the lower portion of the battery cell stack 120 and side portions extending upward from both ends of the bottom portion. However, the module frame 200 is not limited to this, and may be replaced with a frame of another shape, such as an L-shaped frame or a mono frame that surrounds the battery cell stack 120 except for the front and back sides. The battery cell stack 120 accommodated inside the module frame 200 can be physically protected through the module frame 200.

The upper plate 400 may cover the open upper side of the module frame 200. The end plate 150 may cover the front and rear surfaces of the battery cell stack 120 that is open in the module frame 200. The end plate 150 may be connected to the front and rear edges of the upper plate 400 and the front and rear edges of the module frame 200 through welding.

Additionally, a thermally conductive resin layer may be formed between the lower surface of the battery cell stack 120 and the bottom of the module frame 200, and the thermally conductive resin layer transfers heat generated from the battery cell 110 to the battery. It may be delivered to the bottom of the module 100 and serve to fix the battery cell stack 120.

Conventional battery modules lacked a structure that could extinguish fire and thermal runaway inside the battery module. In particular, when high-temperature and high-pressure venting gas is generated from a battery cell, the venting gas may spread to adjacent battery cells and battery modules, causing chain explosions and thermal runaway.

Accordingly, the battery module 100 according to this embodiment includes an automatic fire extinguishing member 500, detects high-temperature and high-pressure venting gas generated from the battery cell 110, and releases fire extinguishing liquid at a specific temperature and pressure. It can prevent and suppress explosion and thermal runaway phenomena.

Below, the automatic fire extinguishing member 500 included in the battery module 100 according to this embodiment will be described in more detail.

Figure 3 is a perspective view showing a fire extinguishing member included in a battery module according to an embodiment of the present invention as seen from below. Figure 4 is a cross-sectional view taken along the cutting line a-a' of Figure 3. Figure 5 is a conceptual diagram showing the operation method of the fire extinguishing member of Figure 4. Figure 6 is an enlarged view of part A of Figure 5. Figure 7 is an enlarged view of part B of Figure 5.

Referring to Figures 1 and 2, an automatic fire extinguishing member 500 may be formed on one side of the module frame 200 of the battery module 100 according to this embodiment. At this time, the automatic fire extinguishing member 500 may be formed on the upper plate 400 of the module frame 200. However, it is not limited to this, and may be formed on the bottom of the U-shaped frame 300 of the module frame 200, and may be formed on the top plate 400 and the bottom of the U-shaped frame 300, respectively. It may also be included.

Referring to Figures 3 and 4, the automatic fire extinguishing member 500 formed on one side of the module frame 200 includes a fire extinguishing body portion 520 that accommodates fire extinguishing liquid; A digestive juice discharge part 530 formed on one side of the fire extinguishing main body 520 and discharging the digestive fluid. And it includes a communication part 540 located inside the digestive juice discharge part 530. In addition, the automatic fire extinguishing member 500 may include a plurality of valves, and more specifically, the first valve 551 formed between the fire extinguishing body portion 520 and the communication portion 540, and the fire extinguishing body portion 520. ) and a second valve 553 formed between the digestive juice discharge part 530, and an auxiliary valve 555 formed in the communication part 540. The valve according to this embodiment may be a rupture disk that can be torn by internal pressure.

At this time, a sensing unit 560 may be formed in the first valve 551, the second valve 553, and the communication unit 540, respectively. The sensing unit 560 may detect the pressure, temperature, and deformation of the valve inside the battery module through the opening of the first valve 551, the second valve 553, and the auxiliary valve 555. The sensing unit 560 formed on the first valve 551, the second valve 553, and the communication part 540 includes the pressure sensor 561, strain sensor 563, and temperature sensor shown in FIGS. 5 to 7. It may include one or more species selected from the group containing (565). Specifically, the sensing unit 560 formed on the first valve 551 and the second valve 553 may include a pressure sensor 561 or a strain sensor 563. Additionally, the sensing unit 560 formed in the communication unit 540 may include a temperature sensor 565. This means that the detection unit 560 formed in the communication unit 540 includes a temperature sensor 565, thereby detecting the opening of the auxiliary valve 555 due to the generation of high-temperature venting gas, and The temperature of the incoming venting gas can be immediately detected and transmitted to the battery pack's automatic fire extinguishing control system. In addition, the pressure sensor 561 or the strain sensor 563 detects the pressure or strain of the first valve 551 and the second valve 553 opened by the venting gas to control the automatic fire extinguishing control system of the battery pack. This information can be transmitted to enable the operation of an automatic fire extinguishing system.

Therefore, when venting gas is generated from the battery cell 110, the auxiliary valve 555, the first valve 551, and the second valve 553 of the automatic fire extinguishing member 500 according to this embodiment can be opened sequentially. there is. Referring to FIG. 5, venting gas may open the auxiliary valve 555 and flow into the communication unit 540. At this time, the sensing unit of the communication unit 540 may detect an increase in temperature of the battery module 100 due to the generation of the venting gas. At this time, the primary valve 551 may be opened by the high-temperature venting gas delivered into the communication part 540. Additionally, as the high-temperature venting gas flows along the fire extinguishing body portion 520 and reaches the second valve 553, the second valve 553 may be opened. At this time, as the second valve 553 is opened, the digestive juice discharge unit 530 is opened and the digestive juice can be released into the battery module 100.

The auxiliary valve 555 may be configured to prevent abnormal operation of the automatic fire extinguishing member due to abnormal detection of pressure, deformation, and temperature. Therefore, before the high-temperature and high-pressure venting gas is generated, the communication part 540 and the first valve 551 are covered by the auxiliary valve 555, so that the first valve 551 is in a situation where high-temperature and high-pressure venting gas is not generated. It can be prevented from opening.

Meanwhile, venting gas may be delivered to the first valve 551 by opening the auxiliary valve 555. Referring to FIG. 6, as described above, a sensing unit 560, that is, a pressure sensor 561 or a strain sensor 563, may be formed on one side of the first valve 551. Accordingly, the venting gas pressure (direction of the arrow in the solid line) introduced as the auxiliary valve 555 is opened may tear the thin central weak portion 551v, thereby opening the first valve 551. At this time, the pressure sensor 561 or strain sensor 563 formed on one side of the first valve 551 detects the pressure or strain caused by the opening of the first valve 551 and sends the corresponding information to the automatic fire extinguishing control system. It can be delivered. Therefore, the automatic fire extinguishing control system that receives the opening of the first valve 551 can deliver a warning notification to the user.

Additionally, by opening the first valve 551, the venting gas delivered to the second valve 553 through the fire extinguishing body unit 520 can be transferred. Referring to FIG. 7, as described above, a sensing unit 560, that is, a pressure sensor 561 or a strain sensor 563, may be formed on the second valve 553. Accordingly, the weak portion 551v, which has a thin thickness at one end, is torn by the venting gas pressure (direction of the arrow in the solid line), thereby opening the second valve 553. At this time, the pressure sensor 561 or strain sensor 563 formed on one side of the second valve 553 detects the pressure or strain caused by the opening of the second valve 553 and sends the corresponding information to the automatic fire extinguishing control system. It can be delivered. The digestive fluid discharge unit 530 is opened through the above information by opening the second valve 553 and the digestive fluid is released, thereby allowing the digestive fluid to be sprayed into the battery module 100.

At this time, the first valve 551 and the second valve 553 may be opened at different pressures. That is, the first valve 551 may be opened in a first pressure range, and the second valve 553 may be opened in a second pressure range. At this time, the pressure at which the first valve 551 opens may be lower than the pressure at which the second valve 553 opens. Accordingly, the first pressure range may be lower than the second pressure range. For example, the first valve 551 may open at a pressure of about 0.05 bar, and the second valve 553 may open at a pressure of about 0.15 bar. In this way, the order in which the valves are opened can be prevented from changing by varying the pressure conditions.

The first valve 551 and the second valve 553 are formed to open in different pressure ranges, and the pressure at which the second valve 553 is opened is set to a pressure range requiring immediate release of digestive juice, so that the battery module ( 100) When internal venting gas is generated, fire extinguishing liquid can be applied quickly and accurately before thermal runaway occurs. At this time, the open area of the second valve 553 may be larger than the open area of the first valve 551. By having such an open wide structure of the valve, venting gas can be released smoothly.

Additionally, the digestive juice discharge unit 530 may further include a digestive juice discharge valve. Therefore, when the second valve 553 is opened, the digestive juice ejection valve is opened by the automatic fire extinguishing control system, or the digestive juice ejection valve is opened by the digestive juice moved by the second valve 553, thereby causing the digestive juice may flow into the battery module 100. Here, the open area of the digestive juice release valve may be larger than the open area of the second valve 553. By having such an open wide structure of the valve, digestive juice can be smoothly introduced into the battery module 100.

Meanwhile, in order for the digestive juice released by the digestive juice discharge unit 530 to flow into the battery module 100, an opening 420 is formed on one side of the module frame 200 where the automatic fire extinguishing member 500 is formed. , the digestive juice discharge portion 530 and the communication portion 540 may be fitted into the opening portion 420.

At this time, a sealing part 570 may be further formed between the fire extinguishing body part 520 and the fire extinguishing liquid discharge part 530, and the sealing part 570 forms a space between the opening part 420 and the fire extinguishing main body part 520. It can be filled so that the digestive juice does not leak out of the battery module 100, but can only flow into the battery module 100.

In addition, the battery module 100 according to this embodiment may include a module frame fastening hole 410 formed in the module frame 200 and an automatic fire extinguishing member fastening hole 510 formed in the automatic fire extinguishing member 500. there is. Accordingly, the module frame 200 and the automatic fire extinguishing member 500 can be coupled by the fastening holes 410 and 510 and the fastening member 600. Accordingly, the module frame fastening hole 410 and the automatic fire extinguishing member fastening hole 510 may be formed at positions corresponding to each other, and may be formed in plural numbers, but are not limited to this and the module frame 200 and the automatic fire extinguishing member 500 It can be freely formed within the range that allows the combination of.

The battery module 100 according to this embodiment includes an automatic fire extinguishing member 500, and the battery module 100 is opened by sequential opening of the auxiliary valve 555, the first valve 551, and the second valve 553. ) Fire extinguishing fluid may be sprayed inside. At this time, the sensing unit 560 formed in the communication unit 540, the first valve 551, and the second valve 553 detects the pressure, deformation, or temperature of each valve 551, 553, and 555 and automatically extinguishes the fire. By transmitting it to the control system, it not only enables the opening of the fire extinguishing liquid discharge unit 530, but also delivers a warning notification to the user, thereby ensuring the safety of the battery module and battery pack and protecting the user.

Below, a battery pack according to another embodiment of the present invention will be described.

The battery pack according to this embodiment includes the battery module described above. In addition, the battery pack of the present invention may be a structure in which one or more battery modules according to this embodiment are collected and packed by adding a battery management system (BMS) and a cooling device that manages the temperature or voltage of the battery, etc. there is.

Furthermore, the battery pack according to this embodiment may include a plurality of the battery modules 100 described above and an automatic fire extinguishing control system to control them. The automatic fire extinguishing control system is connected to the automatic fire extinguishing member 500 and can transmit temperature and pressure information of the battery module 100 to the automatic fire extinguishing member 500.

That is, the automatic fire extinguishing member 500 connected to the automatic fire extinguishing control system transmits a warning sound to the user when it reaches the primary valve 551 opening pressure standard or the primary valve 551 opening temperature standard, thereby encouraging the user to evacuate. can do.

In addition, the automatic fire extinguishing member 500 connected to the automatic fire extinguishing control system opens the secondary valve 553 to release digestive fluid when the secondary valve 553 opening pressure standard or the secondary valve 553 opening temperature standard is reached. By opening the portion 530 and releasing the digestive juice, the safety of the battery module 100 and the battery pack can be secured.

The battery pack can be applied to various devices. These devices can be applied to transportation means such as electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto and can be applied to various devices that can use battery modules, and this also falls within the scope of the present invention. .

In the above, preferred embodiments of the present invention have been shown and described, but the present invention is not limited to the specific embodiments described above, and may be used in the technical field to which the invention pertains without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be understood individually from the technical idea or perspective of the present invention.

100: battery module
110: battery cell
120: Battery cell laminate
150: End plate
200: module frame
300: U-shaped frame
400: upper plate
410: Module frame fastening hole
420: opening
500: Absence of automatic fire extinguishing
510: Automatic fire extinguishing member fastening hole
520: Fire extinguishing main body
530: Digestive juice discharge unit
540: Communication part
551: first valve
553: second valve
555: Auxiliary valve
560: detection unit
561: Pressure sensor
563: Strain sensor
565: Temperature sensor
570: Sealing part
600: fastening member

Claims (12)

A battery cell stack in which a plurality of battery cells are stacked;
a module frame accommodating the battery cell stack; and
It includes an automatic fire extinguishing member formed on the module frame,
The automatic fire extinguishing member,
A fire extinguishing body portion that accommodates the digestive juice;
A digestive juice discharge portion formed on one side of the fire extinguishing main body and through which the digestive fluid is discharged; and
It includes a communication part located inside the digestive juice discharge part,
A first valve is formed between the fire extinguishing body portion and the communication portion,
A second valve is formed between the digestive main body and the digestive juice discharge part,
A battery module in which an auxiliary valve is formed in the communication part. In paragraph 1:
A battery module in which a sensing part is formed in each of the first valve, the second valve, and the communication part. In paragraph 2,
The sensing unit formed on the first valve and the second valve includes a pressure sensor or a strain sensor. In paragraph 2,
The detection unit formed in the communication part is a battery module including a temperature sensor. In paragraph 1:
When venting gas is generated from the battery cell, the auxiliary valve, the first valve, and the second valve are sequentially opened,
As the second valve is opened, the digestive juice discharge portion is opened and the digestive juice is released. In paragraph 5,
The first valve and the second valve are battery modules including a weak portion having a relatively thin thickness. In paragraph 5,
The first valve and the second valve are each opened at different pressures. In paragraph 7:
A battery module in which the pressure at which the first valve opens is lower than the pressure at which the second valve opens. In paragraph 1:
An opening is formed on one side of the module frame where the automatic fire extinguishing member is formed,
The battery module wherein the digestive juice discharge part and the communication part are fitted into the opening. In paragraph 9:
Further comprising a sealing portion formed between the fire extinguishing body portion and the fire extinguishing liquid discharge portion,
The sealing part is a battery module that fills the space between the opening and the fire extinguishing main body. In paragraph 1:
A battery module in which the module frame and the automatic fire extinguishing member are coupled by a fastening member. A battery pack including the battery module according to claim 1.