KR20230040125A - Battery module and battery pack including the same - Google Patents

Abstract

According to an embodiment of the present invention, a battery module comprises: a battery cell laminate in which a plurality of battery cells are stacked; a module frame accommodating the battery cell laminate; and an end plate covering front and rear surfaces of the battery cell laminate that is opened from the module frame. A venting hole is formed in the end plate. The venting hole is formed at a portion spaced apart from a central portion of the end plate.

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 including the same, and more particularly, to a battery module having improved safety and a battery pack including the same.

As the use of portable devices such as mobile phones, laptop computers, camcorders, and digital cameras has become commonplace in modern society, development of technologies in fields related to the above mobile devices has become active. In addition, secondary batteries capable of charging and discharging are a solution to air pollution, such as existing gasoline vehicles using fossil fuels, electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles ( P-HEV), etc., the need for development of secondary batteries is increasing.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. , it is in the limelight due to its very low self-discharge rate and high energy density.

These lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive electrode active materials and negative electrode active materials, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate coated with such a positive electrode active material and a negative electrode active material are disposed with a separator therebetween, and a battery case in which the electrode assembly is sealed and housed together with an electrolyte solution.

In general, lithium secondary batteries can be classified into a can-type secondary battery in which an electrode assembly is embedded in a metal can and a pouch-type secondary battery in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of an exterior material.

In the case of secondary batteries used in small devices, 2-3 battery cells are disposed, but in the case of secondary batteries used in medium-large devices such as automobiles, a battery module electrically connecting multiple battery cells this is used In this battery module, capacity and output are improved by forming a battery cell stack in which a plurality of battery cells are connected in series or parallel to each other. In addition, one or more battery modules may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.

When the temperature of the secondary battery is 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, in a battery module or battery pack having a plurality of secondary batteries, that is, battery cells, the temperature of a battery module or battery pack having a plurality of battery cells may increase rapidly and severely due to the sum of heat emitted from the plurality of battery cells in a narrow space. In other words, in the case of a battery module in which a plurality of battery cells are stacked and a battery pack equipped with such a battery module, high output can be obtained, but it is not easy to remove heat generated from the battery cells during charging and discharging. If the heat dissipation of the battery cell is not performed properly, the battery cell deteriorates rapidly, shortens its lifespan, and increases the possibility of explosion or ignition.

Moreover, battery modules included in vehicle battery packs are often exposed to direct sunlight and may be placed in high temperature conditions such as summer or desert areas.

In the case of a conventional battery module, when a flame is generated due to the explosion or ignition inside the battery module, there is no structure in which the flame and gas can be effectively discharged. Therefore, as a plurality of battery modules are adjacent to each other, flames generated in one battery module could be transferred and propagated to adjacent battery modules. In particular, when a thermal runaway propagation phenomenon occurs, it is very vulnerable to a chain reaction between conventional battery modules.

Therefore, in order to solve the above problems, there is a need for a structure capable of delaying flame transition and delaying a chain reaction between adjacent modules while a gas or the like is released when a flame is generated inside the battery module.

An object to be solved by the present invention is to provide a battery module having improved safety and a battery pack including the same.

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

A battery module according to an embodiment of the present invention includes a battery cell laminate in which a plurality of battery cells are stacked; a module frame accommodating the battery cell stack; and end plates covering the front and rear surfaces of the battery cell stack, which are open from the module frame, and a venting hole is formed in the end plate, and the venting hole is formed at a portion spaced apart from a central portion of the end plate. .

At least one venting hole may be formed on the end plate and spaced apart from each other.

The venting hole may be formed to be positioned at the same height on the end plate.

The venting hole may be formed on an upper side based on a center of the end plate.

The battery module according to the present embodiment may further include an insulating cover formed between the battery cell stack and the end plate.

An area of the insulating cover corresponding to the location of the venting hole may be formed to have a smaller thickness than other areas of the insulating cover.

The insulating cover may be melted during an internal flame, and a gas discharge path through the venting hole may be formed.

Gas generated during the internal flame may be discharged to the outside through the venting hole.

The battery module according to another embodiment of the present invention may further include an insulating cover coupling hole formed on the end plate, and the end plate and the insulating cover may be fixedly coupled through the insulating cover coupling hole. .

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

In the battery module according to an embodiment of the present invention, since a venting hole is formed in an end plate, gas can be effectively discharged to the outside when a flame is generated in the battery module, thereby delaying the propagation of the flame.

In addition, since the area of the insulating cover corresponding to the venting hole is formed to have a smaller thickness than other areas of the insulating cover, it is quickly melted when a flame is generated, so that a gas discharge path can be secured.

In addition, an area of the insulating cover corresponding to the venting hole is blocked until a flame occurs, thereby ensuring insulation performance of the battery module.

However, the effects of the present invention are not limited to the above-mentioned effects, and effects not mentioned will be clearly understood by those skilled in the art from this specification and the accompanying drawings.

1 is an exploded perspective view of a battery module according to an embodiment of the present invention.
FIG. 2 is a view showing an assembled state of the battery module of FIG. 1 .
3 is a view showing an end plate of a battery module according to an embodiment of the present invention.
4 is a view showing an insulating cover and an end plate of a battery module according to an embodiment of the present invention.
5 is a view showing a cross section of the insulating cover cut along the P plane of FIG. 4 .
6 is a view showing an insulating cover and an end plate of a battery module according to another embodiment of the present invention.
FIG. 7 is a perspective view illustrating one battery cell included in the battery cell stack of FIG. 1 .

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

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

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

In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" or "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where another part is in the middle. . Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. In addition, to be "on" or "on" a reference part means to be located above or below the reference part, and to necessarily be located "above" or "on" in the opposite direction of gravity does not mean no.

In addition, throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

In addition, throughout the specification, when it is referred to as "planar image", it means when the target part is viewed from above, and when it is referred to as "cross-sectional image", it means when a cross section of the target part cut vertically is 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 only used to distinguish one component from another.

Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 .

1 is an exploded perspective view of a battery module according to an embodiment of the present invention. FIG. 2 is a view showing an assembled state of the battery module of FIG. 1 .

Referring to FIG. 1, 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 frame 200 accommodating the battery cell stack 120. , and an end plate 150 covering the front and rear surfaces of the battery cell stack 120 that is open from the module frame 200 . In addition, the end plate 150 may include a front end plate 151 covering the front surface of the battery cell stack 120 and a rear end plate 152 covering the rear surface.

At this time, the battery module according to the present embodiment further includes an insulating cover 190 formed between the battery cell stack 120 and the end plate 150, in particular, between the bus bar frame 130 and the end plate 150. can include The insulating cover 190 may be formed both between the battery cell stack 120 and the front end plate 151 and between the battery cell stack 120 and the rear end plate 152 . In addition, the insulating cover 190 may be formed of a plastic material.

The battery cell 110 is preferably a pouch type battery cell. For example, referring to FIG. 7 , the battery cell 110 according to this embodiment has two electrode leads 111 and 112 facing each other so that one end 114a and the other end 114b of the battery body 113 face each other. ) have structures protruding from each other. The battery cell 110 may be manufactured by adhering both ends 114a and 114b of the case 114 and both side surfaces 114c connecting them in a state in which an electrode assembly (not shown) is accommodated in the battery case 114. can In other words, the battery cell 110 according to this embodiment has a total of three sealing parts 114sa, 114sb, and 114sc, and the sealing parts 114sa, 114sb, and 114sc are sealed by a method such as thermal fusion. , the other side may be made of the connecting portion 115. Between both ends 114a and 114b of the battery case 114 is defined in the longitudinal direction of the battery cell 110, and one side portion 114c and a connection portion connecting both ends 114a and 114b of the battery case 114 (115) can be defined in the width direction of the battery cell (110).

The connection part 115 is a region extending along one edge of the battery cell 110 , and a protrusion 110p of the battery cell 110 may be formed at an end of the connection part 115 . The protruding portion 110p may be formed on at least one of both ends of the connecting portion 115 and may protrude in a direction perpendicular to a direction in which the connecting portion 115 extends. The protrusion 110p may be positioned between one of the sealing parts 114sa and 114sb of both ends 114a and 114b of the battery case 114 and the connection part 115 .

The battery case 114 generally has a laminate structure of a resin layer/metal thin film layer/resin layer. For example, when a battery case surface is made of an O (oriented)-nylon layer, when a plurality of battery cells are stacked to form a medium or large battery module, they tend to slide easily due to external impact. Therefore, in order to prevent this and maintain a stable stacked structure of battery cells, an adhesive member such as adhesive adhesive such as double-sided tape or chemical adhesive bonded by a chemical reaction during bonding is attached to the surface of the battery case to form a battery cell stack. (120) can be formed. In this embodiment, the battery cell stack 120 may be stacked in the y-axis direction and accommodated in the module frame 200 in the z-axis direction.

The module frame 200 includes a frame member 300 covering the bottom and both sides of the battery cell stack 120 with open top, front and rear surfaces, and an upper plate 400 covering the top of the battery cell stack 120. ). However, the module frame 200 is not limited thereto, and may be replaced with a frame having another shape such as an L-shaped frame or a mono frame surrounding the battery cell stack 120 except for the front and rear surfaces. The battery cell stack 120 accommodated inside the module frame 200 may be physically protected through the module frame 200 . At this time, the frame member 300 may include a frame bottom portion 300a supporting the lower portion of the battery cell stack 120 and frame side portions 300b extending upward from both ends of the frame bottom portion 300a, respectively. The frame bottom portion 300a may cover the lower surface of the battery cell stack 120, and the frame side portion 300b may cover both side surfaces of the battery cell stack 120. Here, the lower surface of the battery cell stack 120 refers to a surface in the -z-axis direction, and both side surfaces of the battery cell stack 120 refer to surfaces in the y-axis and -y-axis directions. However, these are the surfaces referred to for convenience of description, and may vary depending on the location of the target object or the location of the observer.

The upper plate 400 may be formed in a plate-like structure surrounding the upper surface (surface in the z-axis direction) except for the lower surface and the both side surfaces surrounded by the frame member 300 . The upper plate 400 and the frame member 300 may form a structure that covers the battery cell stack 120 up, down, left and right by being joined by welding in a state where corresponding corner portions are in contact with each other. The battery cell stack 120 may be physically protected through the upper plate 400 and the frame member 300 . To this end, the upper plate 400 and the frame member 300 may include a metal material having a predetermined strength.

At this time, the battery module 100, the bus bar frame 130 located between the battery cell stack 120 and the end plate 150, specifically between the battery cell stack 120 and the insulating cover 190 contains more Accordingly, the battery cell stack 120 and the bus bar frame 130 may be coupled to form a cell assembly. A plurality of bus bars mounted on the bus bar frame 130 may protrude from the battery cells 110 and contact electrode leads 111 mounted on the bus bar frame 130 .

In addition, the battery module 100 according to this embodiment further includes a thermally conductive resin layer 310 positioned between the lower surface of the battery cell stack 120 and the bottom portion 300a of the frame member 300, The thermally conductive resin layer 310 may serve to transfer heat generated from the battery cell 110 to the bottom of the battery module 100 and to fix the battery cell stack 120 .

In addition, according to an embodiment of the present invention, after covering the cell assembly inserted into the module frame 200 with the upper plate 400, the battery module shown in FIG. 2 can be formed.

Hereinafter, the end plate and the insulating cover of the battery module according to the present embodiment will be described in detail with reference to FIGS. 3 to 5 .

3 is a perspective view illustrating an end plate included in a battery module according to an embodiment of the present invention. 4 is a perspective view illustrating an end plate and an insulating cover included in a battery module according to an embodiment of the present invention. 5 is a view showing a cross section of the insulating cover cut along the P plane of FIG. 4 .

Conventionally, when a flame occurs inside a battery module, there is no structure capable of effectively discharging gas caused by the flame. Therefore, when a plurality of battery modules are adjacent, the risk of a flame generated in one battery module being transferred and propagated to an adjacent battery module is very high, and in particular, when a thermal runaway propagation phenomenon occurs, it causes a chain reaction between battery modules. It was very vulnerable, so it was difficult to secure safety.

Accordingly, referring to FIG. 3 , a venting hole 500 is formed in the end plate 150 according to the present embodiment. At this time, the venting hole 500 is formed at a portion spaced apart from the central portion of the end plate 150 . That is, the venting hole 500 may be formed on the upper, lower, left, and right sides of the end plate 150 based on the center and the center.

At this time, at least one venting hole 500 may be formed on the end plate 150 and spaced apart from each other. Here, at least one or more may indicate that a singular number or a plurality may be formed. Accordingly, the venting hole 500 may be formed singly or in plural on the end plate 150 .

By forming the venting hole 500 in the end plate 150, it is possible to effectively discharge gas generated during internal flame. In particular, since a plurality of gas discharge paths are formed by a plurality of spaced apart venting holes, gas can be effectively discharged.

As described above, a plurality of venting holes 500 may be formed, and the venting holes 500 may be formed to be positioned at the same height on the end plate 150 . In this case, the same height on the end plate 150 may indicate the z-axis direction in FIG. 1 . Accordingly, the venting hole 500 formed on the end plate 150 may be formed to be positioned upward by the same length in the z-axis direction from the lower surface of the end plate.

In addition, the plurality of venting holes 500 may be formed on both left and right sides of the center of the end plate 150 . In particular, the plurality of venting holes 500 may be formed in the same number on the left and right sides so as to be symmetrical to each other. Gas generated in the battery module can be smoothly discharged to the outside of the battery module by the symmetrically formed venting hole 500 .

In this case, the venting hole 500 may be formed on the upper side based on the center of the end plate 150 . That is, referring to FIG. 1 , the venting hole 500 may be formed to be positioned above the end plate 150 in the z-axis direction based on the center of the end plate 150 .

In the event of a fire inside the module, the insulating cover 190 may melt. Accordingly, a path blocked by the insulating cover 190 is opened, and a gas discharge path formed to be connected to the venting hole 500 , that is, a gas discharge path through the venting hole 500 may be formed. At this time, since the molten residues of the insulating cover 190 move downward by gravity, it is difficult to discharge gas through a structure formed at a position corresponding to the lower part. Also, the gas can move generally upward as a gas. Therefore, the venting hole 500 according to the present embodiment is formed to be biased toward the upper part based on the center of the end plate 150, so that the gas generated during the internal flame is not obstructed by the residue of the insulation cover 190. can be effectively discharged to the outside by the venting hole 500.

In addition, the venting hole 500 is formed on the upper part of the end plate 150, and when a plurality of venting holes 500 are formed, they are formed to be positioned at the same height, so that the transfer of flame to adjacent modules can be effectively suppressed. . When the flame is ejected through the venting hole 500, the flame may be highly likely to eject toward the top. Therefore, it is highly likely that the flame will be transferred to adjacent modules by the venting hole 500 formed in the lower portion. Therefore, in the battery module according to the present embodiment, the venting hole 500 is formed on the upper part of the end plate 150 and the venting hole 500 is formed at a constant height, thereby suppressing the transfer of flame to the adjacent module and battery The safety of the module can be improved.

The venting hole 500 may have any shape that facilitates gas discharge. Specifically, it may have one or more shapes selected from among shapes selected from a circle, an ellipse, or a polygon, and more specifically, may have a circular shape. In addition, when a plurality of venting holes 500 are formed, each venting hole 500 may have a different shape or the same shape.

In addition, as described above, an insulating cover 190 may be further formed between the battery cell stack 120 and the end plate 150 . In this case, the region 190H of the insulating cover 190 corresponding to the position of the venting hole 500 may be formed to have a smaller thickness than other regions of the insulating cover 190 . That is, the thickness W2 of the region 190H of the insulating cover 190 corresponding to the location of the venting hole 500 may be made thinner than the thickness W1 of other regions of the insulating cover 190 . Accordingly, the region 190H of the insulating cover 190 corresponding to the position of the venting hole 500 among the regions of the insulating cover 190 may melt faster than other regions of the insulating cover 190 . Accordingly, the venting hole 500 on the end plate 190 serves as a movement path for internal flame and gas, and the flame and gas can be discharged to the outside of the battery module. In particular, the region 190H of the insulating cover 190 corresponding to the position of the venting hole 500 is melted before other regions of the insulating cover 190, so that the gas is discharged through the venting hole 500 and the other regions are simultaneously melted. Insulation performance in the region can be secured for the longest period of time.

Hereinafter, an insulating cover and an end plate formed on a battery module according to another embodiment of the present invention will be described with reference to FIG. 6 . Since there are overlapping contents of the above-described battery module and the insulating member included in the battery module, the above contents are omitted to avoid redundant description.

6 is a view showing an insulating cover and an end plate of a battery module according to another embodiment of the present invention.

Referring to FIG. 6 , the end plate 150 according to the present embodiment may further include a hole 155 for coupling an insulating cover. Therefore, the end plate 150 and the insulating cover 190 may be fixedly coupled through the hole 155 for coupling the insulating cover.

The insulation cover 190 is formed to secure insulation performance, and is formed to be fixedly coupled to the end plate 150, thereby preventing movement of the insulation cover 190 and thereby preventing degradation of insulation performance. In addition, even when an internal flame occurs, the insulation cover 190 prevents collapse of non-melted portions, thereby maximizing the performance of the insulation cover.

The battery module described above may be included in a battery pack. The battery pack may have a structure in which one or more battery modules according to the present embodiment are gathered and packed by adding a battery management system (BMS) for managing temperature or voltage of the battery and a cooling device.

The battery pack may be applied to various devices. These devices can be applied to means of transportation such as electric bicycles, electric vehicles, hybrid vehicles, etc., but the present invention is not limited thereto and can be applied to various devices capable of using a battery module, which also falls within the scope of the present invention. .

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and is common in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Of course, various modifications and implementations are possible by those with knowledge of, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

110: battery cell
120: battery cell stack
130: bus bar frame
150: end plate
190: insulation cover
200: module frame
300: frame member
300a: frame bottom
300b: frame side part
400: upper plate
500: venting hall

Claims (10)

a battery cell laminate in which a plurality of battery cells are stacked;
a module frame accommodating the battery cell stack; and
And an end plate covering the front and rear surfaces of the battery cell stack that is open from the module frame,
A venting hole is formed in the end plate,
The battery module wherein the venting hole is formed in a portion spaced apart from the central portion of the end plate. In paragraph 1,
The battery module wherein at least one venting hole is spaced apart on the end plate. In paragraph 2,
The battery module wherein the venting hole is formed to be positioned at the same height on the end plate. In paragraph 1,
The battery module wherein the venting hole is formed on the upper side based on the center of the end plate. In paragraph 1,
The battery module further comprising an insulating cover formed between the battery cell stack and the end plate. In paragraph 5,
A region of the insulating cover corresponding to the position of the venting hole is formed to be thinner than other regions of the insulating cover. In paragraph 5,
The insulating cover is melted during an internal flame,
A battery module in which a gas discharge path is formed through the venting hole. In paragraph 7,
A battery module in which gas generated during the internal flame is discharged to the outside through the venting hole. In paragraph 5,
Further comprising a hole for coupling the insulating cover formed on the end plate,
The battery module wherein the end plate and the insulating cover are fixedly coupled through the insulating cover coupling hole. A battery pack comprising the battery module of claim 1.

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