Battery module and battery pack including said battery module

Abstract

A battery module according to one embodiment of the present invention includes a plurality of battery cell stacks including a plurality of battery cells, a frame member that houses a plurality of the battery cell stacks, and at least one partition structure arranged between the plurality of the battery cell stacks, the partition structure including two plate-shaped members parallel to the battery cells and a venting passage formed by the two plate-shaped members, each of the plate-shaped members including an inlet portion formed to be openable and closable.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0112602 dated August 25, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the battery module, and more particularly to a battery module having improved safety and venting performance and a battery pack including the battery module. [Background technology]

[0003] With the technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. As a result, research on secondary batteries that can meet various requirements is being actively conducted.

[0004] Secondary batteries have attracted much attention as an energy source for power devices such as electric bicycles, electric cars, and hybrid electric cars, as well as for mobile devices such as mobile phones, digital cameras, and laptop computers.

[0005] In recent years, the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, and the demand for medium- to large-sized modular battery packs that assemble battery modules in which many secondary batteries are connected in series / parallel is increasing. A battery pack mainly comprises a battery module consisting of at least one battery cell, and is configured by adding other components using at least one battery module. Since the battery cells that make up the battery module are composed of secondary batteries that can be charged and discharged, such high-output, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In particular, small mobile devices use one or two to four battery cells per device, whereas medium- to large-sized devices such as automobiles require high output and large capacity. Therefore, medium- to large-sized battery modules in which many battery cells are electrically connected are used.

[0006] Since it is preferable for medium- to large-sized battery modules to be manufactured as small and lightweight as possible, prismatic batteries and pouch-shaped batteries, which can be stacked with a high degree of integration and have a small weight relative to their capacity, are mainly used as battery cells for medium- to large-sized battery modules.

[0007] In this integrated state, if some of the battery modules are subject to overvoltage, overcurrent, or overheating, the safety and operating efficiency of the battery modules may become an issue. In particular, the capacity of battery modules is gradually increasing to improve driving distance, and accordingly, it is necessary to design a structure that meets the strengthened safety standards and ensures the safety of the vehicle and the driver.

[0008] FIG. 1 is a perspective view of a conventional battery module.

[0009] As shown in Fig. 1, a plurality of battery modules 1 are arranged adjacent to each other when a battery pack is constructed. In this case, if thermal runaway occurs in one battery module 1, the battery module 1 in which thermal runaway occurs must be quickly evacuated to the outside, otherwise the high-temperature gas and flames accumulated inside will explode all at once and spread to the adjacent battery modules 1. This will cause a chain reaction of thermal runaway in the battery modules 1, and damage to the battery modules 1 will also be spread.

[0010] Therefore, even if thermal runaway occurs, it is necessary to prevent the spread to adjacent modules and minimize damage, and therefore there is a need for a structure that can effectively exhaust gases and flames generated within some battery modules without further migration, thereby minimizing the damage. Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present invention is to provide a battery module and a battery pack including the battery module, which can quickly exhaust flames and gas to the outside to prevent a thermal runaway phenomenon from transferring between a battery cell and the battery module even if an ignition phenomenon occurs within the battery module.

[0012] The problems that the present invention is intended to solve are not limited to those described above, and problems not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Means for solving the problem]

[0013] A battery module according to one embodiment of the present invention includes a plurality of battery cell stacks including a plurality of battery cells, a frame member that houses a plurality of the battery cell stacks, and at least one partition structure arranged between the plurality of the battery cell stacks, the partition structure including two plate-shaped members parallel to the battery cells and a venting passage formed by the two plate-shaped members, each of the plate-shaped members including an inlet portion formed to be openable and closable.

[0014] The inlet portion may include a first opening formed by opening the plate-shaped member, a blocking plate corresponding to the first opening and covering the first opening, and a plurality of support portions coupled to the blocking plate.

[0015] Each of the plurality of support portions may include a pillar portion inserted into a hole formed in the blocking plate, a flange portion formed at a side end of the venting passage of the pillar portion, and an elastic portion coupled to a portion of the pillar portion to support the flange portion and the blocking plate in a state in which the gap between the flange portion and the blocking plate can be changed.

[0016] The elastic portion may be a spring.

[0017] The blocking plate may be configured to move toward the flange portion by pressure of gas flowing in through the first opening portion to open the inlet portion.

[0018] The partition structure may include one end in a longitudinal direction of the battery cell stack and another end located opposite the one end, the first opening may be formed adjacent to the one end, and the other end may be connected to a first exhaust port communicating with the outside of the battery module.

[0019] The battery pack may further include a first end plate and a second end plate covering both ends of the battery cell stack in a longitudinal direction, respectively, and the first end plate may include the first exhaust hole.

[0020] The battery pack may further include at least one outer venting passage disposed on a side opposite to the side of the battery cell stack facing the partition structure.

[0021] The outer venting passage may include one end and an opposite end in a longitudinal direction of the battery cell stack, and may include a second opening formed adjacent to the one end and open toward the battery cell stack.

[0022] The other end of the outer venting passage may be connected to a second exhaust port communicating with the outside of the battery module.

[0023] The second end plate does not include the first exhaust port, and a first opening of the venting passage may be connected to the outer venting passage with a space provided between an end of the battery cell stack and the second end plate.

[0024] A battery pack according to another embodiment of the present invention includes the above-described battery module. Effect of the Invention

[0025] According to the embodiments, the battery module of the present invention and the battery pack including the battery module can prevent the transfer of thermal runaway to adjacent battery modules by blocking the transfer of the fire to other adjacent battery cell stacks within the battery module even if a fire occurs in some battery cell stacks within the battery module, and at the same time quickly exhausting gas and flames to the outside of the battery module.

[0026] The effects of the present invention are not limited to those described above, and effects not mentioned will be apparent to those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a conventional battery module. [Diagram 2] 1 is a perspective view of a battery module according to an embodiment of the present invention; [Diagram 3] FIG. 3 is an exploded perspective view of the battery module of FIG. 2. [Figure 4] 4 is a cross-sectional view taken along line IV-IV of FIG. 2. [Diagram 5] 3 is an enlarged view of a portion in which an inlet portion is formed in FIG. 2. [Figure 6] 5 is an enlarged view of a portion VI in FIG. 4. [Figure 7A] 3 is a diagram for explaining gas discharge when thermal runaway occurs inside the battery module of FIG. 2. [Figure 7B] 3 is a diagram for explaining gas discharge when thermal runaway occurs inside the battery module of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0029] In order to clearly explain the present invention, parts not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0030] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown. In order to clearly express various layers and regions in the drawings, the thicknesses are exaggerated. In the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0031] Additionally, throughout the specification, when a part "comprises" other elements, this means that it can further include the other elements, not excluding the other elements, unless otherwise specified to the contrary.

[0032] Also, throughout the specification, a reference to "in a plane" means a portion of the subject matter viewed from above, and a reference to "in cross section" means a portion of the subject matter viewed from the side along a vertical cut.

[0033] Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS.

[0034] FIG. 2 is an oblique view of a battery module according to one embodiment of the present invention, FIG. 3 is an exploded oblique view of the battery module of FIG. 2, FIG. 4 is a drawing showing a cross section along IV-IV' of FIG. 2, FIG. 5 is a drawing showing an enlarged portion of FIG. 2 where an inlet portion is formed, and FIG. 6 is a drawing showing an enlarged portion of FIG. 4, VI.

[0035] 2 to 4, a battery module 10 according to an embodiment of the present invention includes a plurality of battery cell stacks 100 including a plurality of battery cells, a frame member 200 that accommodates lower and side surfaces of the plurality of battery cell stacks 100 and has open front and rear surfaces, a partition structure 300 disposed between adjacent battery cell stacks 100 among the plurality of battery cell stacks 100, a first end plate 410 and a second end plate 420 adjacent to the front and rear surfaces of the battery cell stacks 100 and covering the open front and rear surfaces of the frame member 200, and an upper cover 500 that covers an upper surface of the battery cell stack 100 and is coupled to the frame member 200. In this description, the front and rear directions may be + and - directions in the y-axis direction in the drawings, the up and down directions may be + and - directions in the z-axis direction, and the side direction may be an x-axis direction.

[0036] The frame member 200 may be a U-shaped frame that receives the bottom and side surfaces of the battery cell stack 100 and has open front and rear surfaces. The upper cover 500 may be configured to be combined with the frame member 200 while covering the top surface of the battery cell stack 100. However, the configurations of the frame member 200 and the upper cover 500 are not limited thereto, and may be an integrally formed rectangular tube shape, or a configuration in which the configuration covering the bottom of the battery cell stack 100 is in the form of a flat plate and a configuration covering the top is in an inverted U-shaped frame, and are not particularly limited thereto.

[0037] The battery cell stack 100 may be formed by stacking a plurality of battery cells. Here, the battery cells are preferably pouch-type battery cells. As an example, the battery cells may be manufactured by housing an electrode assembly in a pouch case of a laminate sheet including a resin layer and an inner layer, and then heat-sealing a sealing portion of the pouch case. The battery cells may be formed in a rectangular sheet structure. The battery cell may be composed of a plurality of battery cells, and the battery cell stack 100 may be formed by stacking the plurality of battery cells so as to be electrically connected to each other.

[0038] Here, a plurality of battery cell stacks 100 may be included in one frame member 200 with a partition structure 300 therebetween. For example, as shown in the drawing, two battery cell stacks 100 may be arranged with their sides facing each other. In this case, the plurality of battery cell stacks 100 may be identically manufactured battery cell stacks with only differences in position. They may also be electrically connected to each other within one frame member 200.

[0039] The first end plate 410 and the second end plate 420 may be made of the same material as the frame member 200 and may be fixed to the frame member 200 by a method such as welding. However, the present invention is not limited to this, and any fixing method that can isolate the inside of the frame member 200 from the external environment may be appropriately applied. In addition, the first end plate 410 and the second end plate 420 are arranged to cover the front and rear surfaces of the battery cell stack 100, for example, the first end plate 410 is arranged to cover the front surface and the second end plate 420 is arranged to cover the rear surface. The differences in their configurations will be described later.

[0040] 2 to 6, the battery module 10 may include a partition structure 300 disposed between adjacent battery cell stacks 100. The partition structure 300 includes a space in which a first plate-shaped member 301 and a second plate-shaped member 302 parallel to the side of the battery cell stack 100 are disposed facing each other, and the space may form a venting passage 320 through which gas and flames generated during thermal runaway pass. The partition structure 300 may be made of the same material as the frame member 200, the upper cover 500, the first end plate 410, the second end plate 420, etc., but is not particularly limited thereto. In addition, the partition structure 300 may be made of a flame-retardant material to prevent flame propagation, and may include a flame-retardant coating layer.

[0041] Each of the first plate-shaped member 301 and the second plate-shaped member 302 of the partition structure 300 may include a first opening 310 that opens facing the battery cell stack 100 disposed adjacent to the first plate-shaped member 301 and the second plate-shaped member 302, respectively. The first opening 310 may be formed particularly adjacent to one end (A) in the longitudinal direction of the partition structure 300. The first opening 310 is connected to a venting passage 320.

[0042] The other end (B) of the partition structure 300 is connected to a first exhaust port 411 formed in a first end plate 410. That is, a vent passage 320 connected to a first opening 310 formed in a first plate-shaped member 301 and a second plate-shaped member 302 of the partition structure 300 is configured to extend inward along the length of the partition structure 300 and open at the other end (B), and the vent passage 320 is configured to be connected to the first exhaust port 411 formed in the first end plate 410 so that gas and flames generated during thermal runaway can be exhausted to the outside.

[0043] The first plate-shaped member 301 and the second plate-shaped member 302 of the partition structure 300 include inlet portions 330 formed to open and close the first opening 310. That is, when thermal runaway occurs and gas and flame are generated, the inlet portions 330 are opened to allow the gas and flame to be discharged to the outside through the first opening 310 and the venting passage 320, and at this time, the inlet portions 330 of the parts where thermal runaway does not occur are kept closed and not opened to isolate them from the parts where thermal runaway occurs. This configuration will be described in more detail below.

[0044] 5 and 6, the inlet 330 includes a blocking plate 331 formed parallel to the first plate-shaped member 301 and the second plate-shaped member 302 of the partition structure 300 to cover the first opening 310, and a plurality of supporting members 332 coupled to the blocking plate 331. The plurality of supporting members 332 are configured to be inserted into holes formed in the blocking plate 331, and one end is fixed to the inner surface of the first plate-shaped member 301 and the second plate-shaped member 302.

[0045] Each of the support parts 332 includes a column part 332c that is coupled to the blocking plate 331 (i.e., inserted into a hole formed in the blocking plate 331), and one end of the column part 332c is fixed to the inner surface of the first plate-shaped member 301 and the second plate-shaped member 302, and the other end of the column part 332c, i.e., the end adjacent to the venting passage 320 side, includes a flange part 332b that protrudes in a direction perpendicular to the length direction of the column part 332c to prevent the blocking plate 331 from being separated. An elastic part 332a is coupled to a part of the column part 332c, and the elastic part 332a may be a spring coupled to the side of the column part 332c as shown in FIG. 6, or may be a spring that wraps the outer surface of the column part 332c or a spring that is embedded inside the column part 332c, although not shown. Any material having elasticity other than a spring can be appropriately selected and used.

[0046] The elastic portion 332a can be supported in a state in which the gap between the flange portion 332b and the blocking plate 331 can be varied. That is, when an external force toward the vent passage 320 is generated, the blocking plate 331 is moved toward the vent passage 320 to narrow the gap between the blocking plate 331 and the flange portion 332b, and when no external force is applied, the blocking plate 331 is supported to be in close contact with the first plate-shaped member 301 and the second plate-shaped member 302, so that the spaces on both sides of the partition structure 300 are isolated from each other. Therefore, when thermal runaway occurs on one side of the partition structure 300, only the inlet portion 330 on the side of the battery cell stack 100 where thermal runaway occurs is opened to discharge gas and flames to the outside, and the inlet portion 330 of the portion where thermal runaway does not occur is not opened and maintained in a closed state, which will be described in detail later.

[0047] Next, the outer venting passage 211 will be described with reference to FIG.

[0048] Referring to FIG. 4, an outer vent passage 211 may be formed along a side surface of the frame member 200. The outer vent passage 211 may be in the form of a tube including a second opening 213 that opens toward the opposing battery cell stack 100, similar to the vent passage 320 of the partition structure 300 described above. The second opening 213 is formed adjacent to the rear surface of the battery cell stack 100 (i.e., adjacent to one end (A) of the partition structure 300), and the opposite end along the length direction, i.e., one end adjacent to the front surface of the battery cell stack 100, may form a second exhaust port 212 that communicates with the outside. In addition, the second opening 213 may be connected to the first opening 310 through a space between the second end plate 420 and the battery cell stack 100. With this configuration, internal flames and gases can be quickly moved and exhausted to the outside.

[0049] The outer venting passage 211 is not particularly limited and may be formed integrally with the frame member 200 or may be attached as a tube-shaped structure separately from the frame member 200. By further including the outer venting passage 211, gas and flames can be exhausted together through the partition structure 300 and the outer venting passage 211 when thermal runaway occurs, and the gas and flames can be exhausted to the outside more quickly.

[0050] Next, the emission of gas and flames when thermal runaway occurs inside the battery module will be described with reference to FIGS. 7A and 7B.

[0051] 7A and 7B are diagrams for explaining gas discharge when thermal runaway occurs inside the battery module of FIG.

[0052] A partition structure 300 having a vent passage 320 is disposed between adjacent battery cell stacks 100, and an outer vent passage 211 formed in a side wall of the frame member 200 is disposed at the outermost side, so that each of the battery cell stacks 100 faces a first opening 310 and a second opening 213. Thus, flames and gases generated in the battery cell stack 100 during thermal runaway can move to the vent passage 320 and the outer vent passage 211 through the first opening 310 and the second opening 213 and be discharged to the outside. In addition, the first opening 310 on the side where thermal runaway does not occur based on the partition structure 300 during thermal runaway is blocked by the inlet portion 330, so that it can be isolated from the thermal runaway stack.

[0053] For example, as shown in FIG. 7A, when thermal runaway occurs in the battery cell stack 100 located on the left side of the drawing, an external force is applied to the blocking plate 331 of the inlet portion 330 in the direction of the arrow, i.e., toward the venting passage 320 (right side) by gas and flame (G) generated in the battery cell stack 100. As a result, the elastic portion 332a of the support portion 332 is compressed, and the inlet portion 330 is opened. The gas and flame (G) enter the venting passage 320 through the opened portion, and then moves along the venting passage 320 and is discharged to the outside. At this time, since the inlet portion 330 facing the battery cell stack 100 located on the right side is closed and not opened, the flame and gas can be quickly discharged to the outside without propagating to the battery cell stack 100 located on the right side of the drawing, and therefore damage to the adjacent battery cell stack 100 can be prevented.

[0054] Meanwhile, as shown in FIG. 7B, when thermal runaway occurs in the battery cell stack 100 located on the right side of the drawing, an external force is applied to the blocking plate 331 of the inlet portion 330 in the direction of the arrow, i.e., toward the venting passage 320 (left side) by the gas and flame (G) generated in the battery cell stack 100. As a result, the elastic portion 332a of the support portion 332 is compressed, and the inlet portion 330 is opened. The gas and flame (G) enter the venting passage 320 through the opened portion, and then moves along the venting passage 320 and is discharged to the outside. At this time, since the inlet portion 330 facing the battery cell stack 100 located on the left side is closed and not opened, the flame and gas can be quickly discharged to the outside without propagating to the battery cell stack 100 located on the left side of the drawing, and therefore damage to the adjacent battery cell stack 100 can be prevented.

[0055] As described above, according to this embodiment, even if thermal runaway occurs in some of the battery cell stacks 100 in the battery module 10, the generated flame and gas can move through the open inlet 330 along the venting passage 320 formed in the partition structure 300 and be quickly discharged to the outside. At this time, the opposite inlet 330 remains closed, thereby suppressing the accumulation of thermal energy inside the battery module 10 and preventing the flame and gas from transferring to other adjacent battery cell stacks 100 and battery modules.

[0056] One or more battery modules according to the present embodiment may be mounted together with various control and protection systems such as a BMS (Battery Management System) and a cooling system to form a battery pack. In particular, when the battery module according to the embodiment of the present invention is disposed in a battery pack including a plurality of battery modules, flames and gases can be quickly exhausted to the outside, so that damage can be prevented from spreading to adjacent battery modules or other components of the battery pack outside the battery module. In addition, when the battery module is disposed, the exhaust port through which gas and flames are exhausted can be disposed adjacent to a location where no components that may damage the outside of the battery pack are disposed (e.g., the rear of the vehicle), thereby minimizing the effects of thermal runaway.

[0057] The battery module or battery pack may be applied to various devices, specifically, to transportation means such as electric bicycles, electric cars, and hybrid vehicles, but is not limited thereto, and may be applied to various devices that can use secondary batteries.

[0058] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but such terms are used only for convenience of explanation and may differ depending on the position of the object in question, the position of the observer, etc.

[0059] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also belong to the scope of the present invention. [Explanation of symbols]

[0060] 10 Battery module 100 Battery cell stack 200 Frame members 300 Bulkhead structure 310 First Opening 320 Venting Passage 330 Inlet 331 Barrier 332 Support part 332a Elastic part 332b Tsuba 332c Pillar 301 First plate-shaped member 302 Second plate-shaped member 410 1st end plate 420 2nd end plate 411 1st outlet 212 2nd outlet

Claims

1. a plurality of battery cell stacks each including a plurality of battery cells; a frame member that houses a plurality of the battery cell stacks; and at least one partition structure disposed between a plurality of the battery cell stacks; the partition structure includes two plate-shaped members parallel to the battery cell and a venting passage formed by the two plate-shaped members; In a battery module, each of the plate-shaped members includes an inlet portion formed to be openable and closable, The inlet portion is A first opening formed in the plate-like member; a blocking plate corresponding to the first opening, the blocking plate covering the first opening; and A plurality of support portions coupled to the blocking plate, Each of the plurality of support portions is a pillar portion to be inserted into a hole formed in the blocking plate; a flange portion formed at a side end portion of the vent passage of the pillar portion; and a resilient portion coupled to a portion of the pillar portion, the resilient portion supporting the flange portion and the blocking plate in a state in which a gap between the flange portion and the blocking plate is variable;

2. The battery module according to claim 1 , wherein the elastic portion is a spring.

3. The battery module according to claim 1 , wherein the blocking plate is configured to move toward the flange portion by pressure of gas flowing in through the first opening portion to open the inlet portion.

4. A plurality of battery cell stacks, each of which includes a plurality of battery cells; a frame member that houses a plurality of the battery cell stacks; and at least one partition structure disposed between a plurality of the battery cell stacks; the partition structure includes two plate-shaped members parallel to the battery cell and a venting passage formed by the two plate-shaped members; In a battery module, each of the plate-shaped members includes an inlet portion formed to be openable and closable, The inlet portion is A first opening formed in the plate-like member; a blocking plate corresponding to the first opening, the blocking plate covering the first opening; and A plurality of support portions coupled to the blocking plate, the partition structure includes one end in a longitudinal direction of the battery cell stack and another end located opposite to the one end, The first opening is formed adjacent to the one end, and the other end is connected to a first exhaust port communicating with an outside of the battery module.

5. a first end plate and a second end plate respectively covering both ends of the battery cell stack in a longitudinal direction, The battery module according to claim 4 , wherein the first end plate includes the first exhaust port.

6. The battery module according to claim 5 , further comprising at least one outer venting passage disposed on a side opposite to the side of the battery cell stack facing the partition structure.

7. 7. The battery module of claim 6, wherein the outer venting passage includes one end and an opposite end in a longitudinal direction of the battery cell stack, and the outer venting passage includes a second opening formed adjacent to the one end and open toward the battery cell stack.

8. The battery module according to claim 7 , wherein the other end of the outer venting passage is connected to a second exhaust port communicating with the outside of the battery module.

9. The second end plate does not include the first exhaust port, 7. The battery module according to claim 6, wherein the first opening of the venting passage is connected to the outer venting passage with a space provided between the end of the battery cell stack and the second end plate.

10. A battery pack comprising the battery module according to any one of claims 1 to 9.

Images