KR20220165187A - 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 in one direction; a module frame that accommodates the battery cell stack and has an inner surface and an outer surface; and an end plate coupled to the module frame and covering the front or rear surface of the battery cell stack, wherein a spacer member for isolating one of the two adjacent battery cells from the other is positioned inside the module frame.

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 with enhanced safety and a battery pack including the same.

As technology development and demand for mobile devices increase, demand for secondary batteries as an energy source is rapidly increasing. Accordingly, a lot of research on secondary batteries that can meet various needs has been conducted.

Secondary batteries are attracting much attention as energy sources for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles as well as mobile devices such as mobile phones, digital cameras, and laptop computers.

Recently, as the need for a high-capacity secondary battery structure, including the use of secondary batteries as an energy storage source, has increased, the demand for medium-large module structure battery packs in which a plurality of secondary batteries are connected in series / parallel to a battery module is increasing. . A battery pack mainly consists of a battery module composed of at least one battery cell, and is constructed by adding other components using the at least one battery module. Since the battery cells constituting the battery module are composed of secondary batteries capable of charging and discharging, such high-output and large-capacity secondary batteries generate a large amount of heat during the charging and discharging process.

1 is an exploded perspective view of a conventional battery module. 2 is a view showing a state in which a thermal runaway phenomenon is transferred when internal ignition of a conventional battery module occurs.

1 and 2, the conventional battery module 10 includes a battery cell stack 12 in which a plurality of battery cells 11 are stacked, a frame 20 for accommodating the battery cell stack 12, It includes end plates 40 and the like formed on the front and rear surfaces of the battery cell stack 12 . A compression pad 19 may be provided between the outermost battery cell 11 of the battery cell stack 12 or some battery cells 11 adjacent to each other, and the compression pad 19 is a battery generated during charging and discharging. By being deformed corresponding to the change in volume of the cells 11, it is possible to prevent excessive pressure from being applied to the battery cells 11 of the battery cell stack 12.

The battery cell stack 12 may be located in a closed structure by the combination of the frame 20 and the end plate 40 . At this time, the frame 20 may have an empty inner space as shown in the A-A section of FIG. 1, and the battery cells 11 are stacked in one direction as shown in FIG. 2 in the empty inner space of the frame 20. can be located

On the other hand, since the plurality of battery cells 11 are densely located in one space without being isolated from each other in the frame 20, when an ignition phenomenon occurs in one battery cell 11 due to overcharging or the like, adjacent A thermal runaway phenomenon may be quickly transferred to other battery cells 11 . Since the temperature of the battery cell 11 can rise to 1000° C. or higher and the pressure to 2 bar level when ignited, even if the compression pad 19 is located between some of the battery cells 11, it is difficult to delay this thermal runaway phenomenon. was difficult.

As such, even if the thermal runaway phenomenon occurs in only one of the plurality of battery cells 11 existing inside the frame 20, high-temperature heat, gas or flame is released to the outside of the battery cell 11, thereby causing the battery module 10 The development of a battery module 10 with improved durability and safety by preventing a continuous ignition phenomenon is required since the ignition phenomenon can be promoted within the bar.

The problem to be solved by the present invention is to provide a battery module and a battery pack including the battery module that prevents the thermal runaway phenomenon from being transferred between battery cells when an ignition phenomenon occurs in the battery module.

However, the problems to be solved by the embodiments of the present invention are not limited to the above problems and can be variously extended within the scope of the technical idea included in the present invention.

A battery module according to an embodiment of the present invention is a battery cell stack in which a plurality of battery cells are stacked in one direction, accommodating the battery cell stack, and combining a module frame having an inner surface and an outer surface and the module frame, , A first cell assembly including an end plate covering the front or rear surface of the battery cell stack, and including at least one battery cell of the battery cell stack inside the module frame, the first cell assembly and Adjacent to it, a second cell assembly including at least one battery cell of the battery cell stack is disposed, and a separation member separating the first cell assembly and the second cell assembly from each other is positioned.

The separation member may extend from the top and bottom of the module frame and be provided in the form of a barrier rib between the first cell assembly and the second cell assembly.

The module frame and the spacer may be integral.

The module frame includes at least two subspaces separated by the spacer, and each of the subspaces has a hole shape defining an inlet formed on an inner surface of the module frame and an outlet formed on an outer surface of the module frame. At least one venting portion may be formed.

The venting part may be formed above the module frame.

The battery cell includes an electrode assembly and a cell case accommodating the electrode assembly, the electrode assembly is sealed by a sealing part of the cell case, and the sealing part of the cell case connects both ends of the cell case to each other. Formed on the side, the sealing portion may be formed in the longitudinal direction of the battery cell.

The venting part may be formed in the end plate.

A discharge direction of the venting unit may form an acute angle with one surface of the module frame on which the venting unit is formed, and a discharge direction of the venting unit may be in a direction from the inlet to the outlet.

The hole of the venting part may be covered by a barrier layer.

The barrier layer may include a material having a melting point of about 300 °C or less.

The barrier layer may include heat-resistant plastic, CFRP (Carbon Fiber Reinforced Plastic), GFRP (Glass Fiber Reinforced Plastics), Mica-based material, Ceramic-based material, or silicon.

The barrier layer may include one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates.

The barrier layer may be positioned between one surface of the module frame on which the venting portion is formed and the battery cell stack.

The barrier layer may fill an inner space of the hole of the venting part.

The barrier layer may include a first barrier layer filling an inner space of the hole of the venting part and a second barrier layer positioned between one surface of the module frame on which the venting part is formed and the battery cell stack.

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

According to embodiments, a continuous thermal runaway phenomenon inside the battery module may be prevented by providing the battery module with a module frame having a modified internal shape.

According to embodiments, since the module frame having holes is provided in the battery module, continuous thermal runaway inside the battery module may be prevented.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is an exploded perspective view of a conventional battery module.
2 is a view showing a state in which a thermal runaway phenomenon is transferred when internal ignition of a conventional battery module occurs.
3 is a perspective view showing a battery module according to an embodiment of the present invention.
4 is a perspective view of a battery cell included in the battery module of FIG. 3 .
5 is a perspective view illustrating a module frame included in the battery module of FIG. 3 .
6 is a cross-sectional view taken along the cutting line BB of FIG. 5;
FIG. 7 is a view showing a state when the battery module provided with the module frame of FIG. 5 is ignited inside.
8 is a perspective view showing a module frame included in a battery module according to another embodiment of the present invention.
9 is a cross-sectional view taken along the cutting line CC of FIG. 8 .
FIG. 10 is a view showing a state when the battery module provided with the module frame of FIG. 8 is ignited inside.
11 is a cross-sectional view showing a battery module according to another embodiment of the present invention.
FIG. 12 is a view showing a state of the battery module of FIG. 11 when the inside is ignited.
FIG. 13 is an enlarged view of portion P in FIG. 11 .

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may be implemented in many different forms other than those described below, and the scope of the present invention is not limited by 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 enlarged or reduced for convenience of description, it is obvious that the contents of the present invention are not limited to those shown. In the following drawings, the thickness of each layer is shown enlarged in order to clearly express various layers and regions. Also, in the following drawings, for convenience of description, thicknesses of some layers and regions are exaggerated.

Also, when a portion of a layer, film, region, board, etc. is described as being "on" or "on" another portion, this means that the layer, film, region, board, etc. portion in question is "directly on" the other portion. In addition, it should be construed as including the case where there is another part in between. Conversely, when a part of a corresponding layer, film, region, plate, etc. is described as being "directly on" another part, it may mean 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 It may not be. On the other hand, similar to the description of being "above" or "on" another part, the description of being "below" or "below" another part will also be understood with reference to the above-described content.

In addition, since the upper/lower surface of a specific member can be determined differently depending on which direction it is based, 'upper surface' or 'lower surface' is defined as meaning two surfaces facing each other on the z-axis in the entire specification. .

In addition, throughout the specification, when a certain part "includes" a certain component, 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", it means when the corresponding part is viewed from above, and when it is referred to as "cross-section", it means when the cross section of the corresponding part cut vertically is viewed from the side.

Hereinafter, a battery module according to an embodiment of the present invention will be described.

3 is a perspective view showing a battery module according to an embodiment of the present invention. 4 is a perspective view of a battery cell included in the battery module of FIG. 3 .

3 and 4, the battery module 100 according to an embodiment of the present invention includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked along one direction, and a battery cell stack 120 ) May include a module frame 200 for accommodating, and an end plate 400 covering the front and / or rear surfaces of the battery cell stack 120.

The battery cell 110 may be provided in a pouch type capable of maximizing the number of stacks per unit area. The battery cell 110 provided in a pouch type may be manufactured by housing an electrode assembly including a positive electrode, a negative electrode, and a separator in a cell case 114 of a laminate sheet and then heat-sealing a sealing portion of the cell case 114. However, the battery cell 110 does not necessarily have to be provided in the form of a pouch, and may be provided in a prismatic, cylindrical, or other various shapes under a level at which a storage capacity required by a device to be mounted in the future is achieved.

Referring to FIG. 4 , the battery cell 110 may include two electrode leads 111 and 112 . The electrode leads 111 and 112 may each protrude from one end of the cell body 113 . Specifically, one end of each electrode lead 111 and 112 is electrically connected to the positive electrode or negative electrode of the electrode assembly by being located inside the battery cell 110, and the other end of each electrode lead 111 and 112 is located outside the battery cell 110. By being drawn out, it can be electrically connected to a separate member, for example, the bus bar 500. Meanwhile, although FIG. 4 shows that the positive and negative leads of the battery cell 110 protrude in opposite directions, this is not necessarily the case, and it is possible for the electrode leads of the battery cell 110 to protrude in the same direction.

Meanwhile, in the battery cell 110, both ends 114a and 114b of the cell case 114 and one side portion 114c connecting them are bonded while the electrode assembly (not shown) is accommodated in the cell case 114. It can be manufactured by 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.

In particular, the sealing parts 114sa, 114sb, and 114sc may include a sealing part 114sc formed in the longitudinal direction of the battery cell and a sealing part 114sa, 114sb formed in the width direction of the battery cell. At this time, the sealing part 114sc formed in the longitudinal direction of the battery cell has a structure of a single folding bent once (once), a non-folding without a bent part, and various types of sealing parts 114sc. can include At this time, a space 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 connecting both ends 114a and 114b of the battery case 114 A space between the and the connecting portion 115 may be defined in the width direction of the battery cell 110 .

The cell case 114 generally has a laminate structure of a resin layer/metal thin film layer/resin layer. For example, when the cell case surface is made of an O (oriented)-nylon layer, when a plurality of battery cells 110 are stacked to form a medium or large battery module 100, they are easily slipped by external impact. there is a tendency Therefore, in order to prevent this and maintain a stable stacked structure of the battery cells 110, an adhesive member such as adhesive adhesive such as double-sided tape or chemical adhesive bonded by a chemical reaction during adhesion is applied to the surface of the cell case 114. It can be attached to form the battery cell stack 120.

The connection part 115 may refer to an area extending along the length direction from one end of the cell case 114 where the above-described sealing parts 114sa, 114sb, and 114sc are not located. A protrusion 110p of the battery cell 110 called a bat-ear may be formed at an end of the connecting portion 115 . In addition, the terrace portion 116 includes the electrode leads 111 and 112 whose parts protrude outside the cell case 114 based on the edge of the cell case 114 and the inside of the cell case 114. It may refer to an area between the cell bodies 113 located at .

The battery cell stack 120 may include a plurality of electrically connected battery cells 110 stacked along one direction. The direction in which the plurality of battery cells 110 are stacked (hereinafter referred to as 'stacking direction') may be the y-axis direction (or -y-axis direction) as shown in FIG. ' can be interpreted as including both +/- directions).

Meanwhile, since the battery cells 110 are disposed along one direction, electrode leads of the battery cells 110 may be positioned on one side or one side and the other side facing the one side of the battery cell stack 120 . As such, the surface on which the electrode leads are located in the battery cell stack 120 may be referred to as the front or rear surface of the battery cell stack 120, where the direction from the front to the rear of the battery cell stack 120 , or the opposite direction may be defined as the longitudinal direction of the battery cell stack 120, may be the x-axis direction. The longitudinal direction of the battery cell stack 120 may be substantially the same as the longitudinal direction of the battery cell 110 .

In addition, the side on which the outermost battery cell 110 is located in the battery cell stack 120 may be referred to as a side surface of the battery cell stack 120, and the side surfaces of the battery cell stack 120 are relative to each other on the y-axis. It can be described as two opposite sides.

The module frame 200 may be for protecting the battery cell stack 120 and electrical components connected thereto from external physical impact. The module frame 200 may be accommodated in the internal space of the battery cell stack 120 and the electrical component module frame 200 connected thereto. Here, the module frame 200 includes an inner surface and an outer surface, and the inner space of the module frame 200 may be defined by the inner surface.

The structure of the module frame 200 may vary. For example, the structure of the module frame 200 may be a structure of a mono frame. Here, the mono frame may be in the form of a metal plate material in which the upper surface, the lower surface, and both sides are integrated. The mono frame can be made by extrusion molding. As another example, the structure of the module frame 200 may be a structure in which a U-shaped frame and an upper plate (upper surface) are combined. In the case of a structure in which a U-shaped frame and an upper plate are combined, the structure of the module frame 200 may be formed by combining the upper plate with the upper side of the U-shaped frame, which is a metal plate material in which the lower surface and both sides are combined or integrated, Each frame or plate can be made by press molding. In addition, the structure of the module frame 200 may be provided in an L-shaped frame structure in addition to a mono frame or a U-shaped frame, and may be provided in various structures not described in the above examples.

The structure of the module frame 200 may be provided in an open form along the longitudinal direction of the battery cell stack 120 . Front and rear surfaces of the battery cell stack 120 may not be covered by the module frame 200 . The front and rear surfaces of the battery cell stack 120 may be covered by a bus bar frame or end plate 400, which will be described later, through which the front and rear surfaces of the battery cell stack 120 are protected from external physical impact. can be protected

The top/bottom, front/rear, and both sides of the module frame 200 may be described based on the contents of the battery cell stack 120 described above. Specifically, the upper and lower surfaces of the module frame 200 are two surfaces facing each other on the z-axis, the front and rear surfaces of the module frame 200 are two surfaces facing each other on the x-axis, and both sides of the module frame 200 are It can be described as two planes facing each other on the y-axis. Here, a direction from the front to the rear or from the rear to the front may be the length direction of the module frame 200 .

Meanwhile, although not shown, a compression pad may be positioned between the battery cell stack 120 and the inner surface of the module frame 200 . At this time, the compression pad may be located between the side of the battery cell stack 120 and the side of the module frame 200, at least of the two battery cells 110 at both ends of the battery cell stack 120 You can face one and the other side.

In addition, a thermally conductive resin may be injected between the inner surface of the battery cell stack 120 and the module frame 200, and the battery cell stack 120 and the module frame 200 are separated by the injected thermal conductive resin. A thermally conductive resin layer (not shown) may be formed between the inner surfaces. At this time, the thermally conductive resin layer may be formed between the lower surface of the battery cell stack 120 and the lower surface of the module frame 200 (or bottom surface, may be referred to as a bottom part).

The end plate 400 may be to protect the battery cell stack 120 and electrical components connected thereto from external physical impact by sealing the open surface of the module frame 200 . To this end, the end plate 400 may be made of a material having a predetermined strength. For example, the end plate 400 may include a metal such as aluminum.

The end plate 400 may be combined (bonded, sealed, or sealed) with the module frame 200 while covering the bus bar frame or bus bar 500 located on one surface of the battery cell stack 120 . Each corner of the end plate 400 may be coupled to a corresponding corner of the module frame 200 by welding or the like. In addition, an insulating cover for electrical insulation may be positioned between the end plate 400 and the bus bar frame. The insulating cover may be located on the inner surface of the end plate 400 and may come into close contact with the inner surface of the end plate 400, but this is not necessarily the case.

The end plate 400 may be two, and may include a first end plate positioned on the front surface of the battery cell stack 120 and a second end plate positioned on the rear surface of the battery cell stack 120. can

Meanwhile, the above-described battery module 100 may be provided with a bus bar frame. The bus bar frame is located on one side of the battery cell stack 120 to cover one side of the battery cell stack 120 and at the same time guide the connection between the battery cell stack 120 and an external device. can At least one of the bus bar 500 and the module connector may be mounted on the bus bar frame. The bus bar frame may include an electrically insulating material. The bus bar frame may limit the contact of the bus bar 500 with other parts of the battery cells 110 other than the parts bonded to the electrode leads 111 and 112 and prevent an electrical short circuit from occurring.

The bus bar frame may be located on the front or rear surface of the battery cell stack 120 . One surface of the bus bar frame may be connected to the front or rear surface of the battery cell stack 120, and the other surface of the bus bar frame may be connected to the bus bar 500. There may be two bus bar frames, and between the first bus bar frame and the rear surface of the battery cell stack 120 and the second end plate located between the front side of the battery cell stack 120 and the first end plate. It may include a second bus bar frame positioned.

The bus bar 500 may be mounted on one surface of the bus bar frame and electrically connect the battery cell stack 120 or the battery cells 110 and an external device circuit. The bus bar 500 is positioned between the battery cell stack 120 or the bus bar frame and the end plate 400, so that it can be protected from external impact, etc., and durability degradation caused by external moisture can be minimized.

The bus bar 500 may be electrically connected to the battery cell stack 120 through the electrode leads 111 and 112 of the battery cell 110 . Specifically, the electrode leads 111 and 112 of the battery cell 110 may be connected to the bus bar 500 by being bent after passing through slits formed in the bus bar frame. The battery cells 110 constituting the battery cell stack 120 by the bus bar 500 may be connected in series or parallel.

Meanwhile, the bus bar 500 may include a terminal bus bar for forming an electrical connection between the battery modules 100 . At least a portion of the terminal bus bar may be exposed to the outside of the end plate 400 in order to be connected to another external battery module 100, and the end plate 400 will be provided with a terminal bus bar opening 400H for this purpose. can The terminal bus bar may be connected to another battery module 100 or a battery disconnect unit (BDU) through a protrusion exposed through the terminal bus bar opening 400H, and may form a high voltage (HV) connection with them.

Although not shown, the battery module 100 may include a sensing member that detects and controls phenomena such as overvoltage, overcurrent, and overheating of the battery cell 110 . The sensing member is for low voltage (LV) connection, where the LV connection may mean a sensing connection for sensing and controlling a voltage of a battery cell. Voltage information and temperature information of the battery cell 110 may be transferred to an external battery management system (BMS) through the sensing member.

The sensing member includes a temperature sensor for sensing the temperature inside the battery module, a sensing terminal for sensing the voltage value of the bus bar 500, and a module for transmitting collected data to an external control device and receiving signals from the external control device. A connector and/or a connecting member for connecting them may be included.

Here, the connecting member is disposed in a form extending along the longitudinal direction from the upper surface of the battery cell stack 120, and may be a flexible printed circuit board (FPCB) or a flexible flat cable (FFC). can

Also, the module connector may be mounted on the above-described bus bar frame, and at least a portion of the module connector may be exposed to the outside through a module connector opening formed in the end plate 400 .

On the other hand, as described above, an ignition phenomenon may occur inside the battery module 100 in which the battery cells 110 are stacked at a high density. When an ignition phenomenon occurs in one battery cell 110, since heat, gas or flame may be transferred to the battery cell 110 adjacent thereto, continuous ignition may occur in the battery cell stack 120. Accordingly, there is a problem in that durability and stability of the battery module 100 or a battery pack including the battery module 100 are deteriorated.

Accordingly, hereinafter, the module frame 200 capable of improving durability and stability of the battery module 100 by preventing continuous ignition between the battery cells 110 will be described.

5 is a perspective view illustrating a module frame included in the battery module of FIG. 3 . 6 is a cross-sectional view taken along the cutting line B-B of FIG. 5; FIG. 7 is a view showing a state when the battery module provided with the module frame of FIG. 5 is ignited inside.

Referring to FIGS. 5 and 6 , the module frame 200 of this embodiment may include a plurality of spacer members 210 partitioning its internal space.

The spacer member 210 may be for dividing a space in which the battery cells 110 are located. By the spacer 210, the module frame 200 may include a plurality of sub-spaces isolated from each other. Accordingly, the battery cells 110 located in the module frame 200 of the conventional battery module 100 may be divided and disposed in the above-described sub-space. A cell assembly including at least one battery cell 110 may be disposed in the sub-space. For example, a first cell assembly and a second cell assembly adjacent to each other may be disposed with the separation member 210 interposed therebetween. In this case, the first cell assembly and the second cell assembly may be isolated from each other by the separation member 210 . If the number of battery cells 110 existing in the conventional module frame 200 was N, the number of battery cells 110 present in the subspace of the module frame 200 of this embodiment is N/2, N/3, or N/2. may be less than that. Here, N may be a natural number.

The spacer member 210 may be provided in various forms.

For example, as shown in FIG. 6 , the spacer member 210 may be a plate-shaped member provided in the form of a barrier rib. Here, the separation member 210 provided in the form of a barrier rib may extend vertically between the upper and lower surfaces of the module frame 200 . The separation member 210 provided in the form of a barrier rib may be integrated with the module frame 200 . However, here, both ends of the separation member 210 provided in the form of a barrier rib may be coupled to the upper or lower surface of the module frame 200, but this is not necessarily the case, and heat, flame, spark, etc. of the battery cell 110 If transmission beyond the separation member 210 can be prevented, both ends of the separation member 210 may be spaced apart from at least one of the upper or lower surface of the module frame 200 .

As another example, the separation member 210 may be provided in a box shape. The box-shaped spacer 210 may have a hollow square tube shape open in the longitudinal direction. Since a plurality of spacer members 210 having a square tube shape are provided in the inner space of the module frame 200, spaces in which the battery cells 110 are located may be separated.

Since the spacer member 210 is located inside the module frame 200, volume expansion due to swelling of the battery cells 110 can be suppressed. Since the spacer 210 is located between the battery cells 110 located in the two sub-spaces, the effect of the volume expansion phenomenon generated in one sub-space on the battery cells 110 in the other sub-space can be minimized. can

Since the separation member 210 is formed on the module frame 200, the compression pad may be omitted from the battery module 100, but this is not necessarily the case, and both the separation member 210 and the compression pad are included in the battery module 100. may be provided. If a compression pad or the like is positioned between the spacer member 210 and the battery cell 110 that are in surface contact with each other, the swelling of the battery cell 110 may be absorbed to some extent through the compression pad. Examples of materials used for the compression pad include polyurethane pads and silicon pads.

The spacer member 210 may be positioned between the battery cells 110 in the module frame 200 to form a heat transfer path from the battery cells 110 toward the module frame 200 . Since the battery cells 110 are sealed inside the module frame 200, the heat of the battery cells 110 is mainly discharged to the outside through the module frame 200. At this time, the battery cells 110 from the module frame ( 200), heat transfer may not be smooth. However, when the spacer 210 is positioned between the battery cells 110, the battery cells 110 positioned close to the spacer 210 are dissipated through the spacer 210 to the module frame 200. Since it is easy, the battery cells 110 in the module frame 200 can be prevented from overheating.

The spacer 210 may form a subspace within the module frame 200 to limit the continuous thermal runaway between the battery cells 110 within a certain range or delay the thermal runaway.

Referring to FIG. 7 , the battery cells 110 may be divided and positioned in sub-spaces of the module frame 200 . Compared to conventional battery modules, as the number of battery cells 110 located in the isolated space is reduced, continuous ignition of the battery cells 110 is prevented, or even if continuous ignition occurs, the phenomenon is within a certain range. can be limited to

Specifically, as shown in FIG. 7 , three spacer members 210 provided in the form of barrier ribs may be positioned within the battery module 100, and thus the battery module 100 may have four sub-spaces. have. When the number of battery cells 110 that can be accommodated in the battery module 100 is N, N/4 battery cells 110 may be positioned in each sub-space. At this time, when ignition occurs in one of the battery cells 110 located in the sub-space, thermal runaway may be easily transferred to the battery cells 110 located in the sub-space, but battery cells located in the other sub-space ( 110), thermal runaway may not be transferred. As such, the battery module 100 has at least two sub-spaces by the spacer member 210, thereby limiting thermal runaway between the battery cells 110 within a certain range, and additional damage can be prevented.

The spacer member 210 may be made of various materials. For example, the spacer member 210 may be made of a material having a high heat transfer rate. When the spacer member 210 is made of a material having a high heat transfer rate, since the spacer member 210 has a conventional cooling fin function, heat dissipation of the battery cells 110 can be more easily achieved. Specifically, the spacer member 210 may be made of aluminum, gold, silver, copper, platinum, or an alloy including these having a high heat transfer rate. As another example, the separation member 210 may be made of a material that can withstand a predetermined pressure and temperature. The spacer member 210 may be made of a material superior in rigidity to conventional compression pads, specifically, a SUS-based metal having excellent heat resistance. As another example, the spacer member 210 may be made of a material similar to that of the module frame 200 . When the separation member 210 is made of a material similar to that of the module frame 200, coupling between the two members may be facilitated. Specifically, the separation member 210 may be made of metal such as aluminum or copper.

Hereinafter, a battery module according to another embodiment of the present invention will be described. The battery module 100 to be described below is similar to the content of the above-described embodiment except that the shape of the module frame 200 is provided differently. Therefore, detailed descriptions of the contents overlapping with those described above will be omitted.

8 is a perspective view showing a module frame included in a battery module according to another embodiment of the present invention. 9 is a cross-sectional view taken along the line C-C of FIG. 8; FIG. 10 is a view showing a state when the battery module provided with the module frame of FIG. 8 is ignited inside.

Referring to FIGS. 8 to 10 , the module frame 200 of this embodiment may include a venting portion 220 penetrating the inner and outer surfaces of the module frame 200 . The module frame 200 of this embodiment prevents the thermal runaway phenomenon of the battery cell 110 from being transferred beyond a certain range through the spacer member 210, and increases the internal temperature and pressure through the venting part 220. By preventing the thermal runaway inside the battery module 100 can be effectively delayed. The battery module 100 of the present embodiment includes a spacer member 210 that prevents transfer of heat and pressure between sub-spaces and a venting part 220 that minimizes pressure and temperature rises, so that the battery module 100 Even if internal ignition occurs, transfer of thermal runaway to other subspaces can be minimized.

The venting part 220 may communicate the inside of the battery module 100 sealed by the module frame 200 and the end plate 400 and the outside of the battery module 100 . The venting unit 220 may be for discharging heat, gas, or flame generated when the battery module 100 internally ignites to the outside of the battery module 100 .

The venting unit 220 may have a hole shape communicating an inlet 220a formed on the inner surface of the module frame 200 and an outlet 220b formed on the outer surface of the module frame 200 .

The venting part 220 may be formed on at least one surface of the module frame 200 . The venting part 220 may be formed on top of the module frame 200 . Also, although not shown, the venting part 220 may be formed on a side surface of the module frame 200 .

The venting unit 220 can prevent a continuous thermal runaway phenomenon by alleviating an internal ignition phenomenon of the module frame 200 and minimizing an increase in pressure or temperature. Specifically, when ignition occurs inside the module frame 200, heat, gas, spark, flame, etc. caused by ignition of the battery cell 110 are discharged to the outside of the battery module 100 through the venting unit 220, The fire is extinguished quickly, and the ignition phenomenon can be more mitigated. In addition, as heat, gas, etc. are discharged through the venting unit 220, an excessive increase in pressure or temperature inside the battery module 100 can be prevented, and the speed at which thermal runaway is transferred in the internal space can also be delayed. can

Referring to FIG. 10 , the venting part 220 may be formed in a subspace of the module frame 200 . In the module frame 200, a vent 220 may be formed on an upper surface of the subspace. The venting part 220 may be formed in each sub-space.

The thermal runaway phenomenon inside the battery module 100 may mainly depend on the amount of heat transferred between the battery cells 110 and the heat accumulated accordingly. In addition, the thermal runaway phenomenon inside the battery module 100 may depend on a high-temperature and high-pressure gas generated during ignition or a convection phenomenon caused by the gas. Since the size of each subspace is smaller than the size of the conventional internal space of the module frame 200, when the battery module 100 internally ignites, the internal temperature or internal pressure may increase rapidly due to heat conduction, heat accumulation, or gas. However, when the venting unit 220 is formed in each subspace, heat, gas, flame, spark, etc. are discharged through the venting unit 220, so that the temperature and pressure of the subspace in which thermal runaway occurs may not greatly increase. . As such, since the temperature and pressure of the sub-space are not excessively increased by the venting unit 220, the thermal runaway phenomenon in the sub-space may be delayed.

In addition, as the temperature and pressure of each sub-space are not significantly increased by the venting unit 220, the amount of heat or pressure transferred from the sub-space where the ignition phenomenon has occurred to the adjacent sub-space may be reduced. As such, since the venting part 220 is formed in the sub-space, the effect of the separation member 210 to concentrate the increase in heat or pressure due to internal ignition into one sub-space can be more easily achieved.

Meanwhile, when the venting part 220 is not formed, when the battery module 100 is ignited, heat, gas, etc. may be compressed in the internal space of the module frame 200, and as a result, the module frame 200 collapses. Or the battery cell 110 inside the module frame 200, the bus bar frame, and the bus bar 500 may be damaged. In addition, when the spacer member 210 is located in the module frame 200 as in the present embodiment, since heat, gas, etc. are more easily compressed in the sub-space when internal combustion occurs, high pressure is formed within a short period of time to sub-space. There is a risk that the separation member 210 separating the spaces may be damaged.

However, when the venting part 220 is formed in each subspace as shown in FIG. 10, since the increase in temperature and pressure in the subspace is minimized by the venting part 220, the separation member 210 controls the temperature inside the subspace, It can be prevented from being damaged by pressure or the like. Therefore, the spacer member 210 is provided to subdivide the enclosed space in the module frame 200, and in order for the effect of the spacer member 210 to appear as intended, the venting part 220 or the venting part 220 and Structures having similar functions may need to be provided in the module frame 200 .

Here, at least one venting part 220 may be formed on the upper surface of each sub-space. As the number of vents 220 formed in each sub-space increases, the ignition phenomenon of the sub-space can be alleviated more rapidly. When there are a plurality of venting units 220 , the venting units 220 may be arranged in rows along one direction and in columns along a direction perpendicular to the one direction.

At this time, the venting part 220 may be entirely formed on one surface of the module frame 200 or the subspace as in the above-described drawings, but not necessarily, and part of one surface of the module frame 200 or the subspace. may be formed in

Meanwhile, in the above description, the venting part 220 is formed on the module frame 200, but the venting part 220 is formed on the end plate 400 or both the module frame 200 and the end plate 400. may be formed in Specifically, bus bars 500 or electrode leads may be intensively disposed in subspaces located at both ends of the module frame 200, and the bus bars 500 or electrode leads charge and discharge the battery cells 110. It may be a configuration that is easy to generate heat. Therefore, in order to prevent continuous ignition inside the battery module 100, it may be preferable to promote heat dissipation of the bus bar 500 or the electrode lead by forming the venting portion 220 on the end plate 400. .

The shape of the inlet 220a and the outlet 220b of the venting part 220 may be a round shape having a curvature as shown in the drawings, but this is not necessarily the case, and the inlet 220a and The outlet 220b may be provided in a circular shape, an elliptical shape, or a polygonal shape having vertices. In addition, since heat, gas, or flame discharged through the venting part 220 is preferably diffused more quickly to the outside of the battery module 100, the size of the outlet 220b is provided larger than that of the inlet 220a. It could be.

Meanwhile, a direction from the inlet 220a of the venting unit 220 toward the outlet 220b may be a discharge direction in which gas inside the battery module 100 is discharged to the outside. In the above drawings, the direction from the inlet 220a of the venting unit 220 to the outlet 220b is perpendicular to one surface of the module frame 200 on which the venting unit 220 is formed, but this is not necessarily the case. A hole structure may be formed so that the discharge direction forms an acute angle with one surface of the module frame 200 by changing the positions of the inlet 220a and the outlet 220b of the ting part 220 . As such, since the hole of the venting part 220 has an inclined structure, exposure of the inside of the battery module 100 is minimized, and a phenomenon in which foreign substances floating in the air enter the inside of the battery module 100 by gravity can be prevented. have.

When the discharge direction is formed at an angle (acute angle) by changing the positions of the inlet 220a and the outlet 220b of the venting unit 220, the direction of heat, gas or flame discharged from the venting unit 220 is changed (adjusted). ) can be As a result, the length of the discharge path may increase, and the gas discharged through the outlet 220b of the venting unit 220 may have a lower temperature. In addition, when the venting portion 220 is formed in a direction in which the battery modules 100 are not adjacent to each other, a phenomenon in which heat propagates between adjacent battery modules 100 may be minimized.

When there are a plurality of venting units 220 , discharge directions of the plurality of venting units 220 may be the same or different from each other. When the plurality of venting units 220 have different discharge directions, gas or the like discharged from the venting units 220 may spread toward a wider space outside the battery module 100 in various directions. Accordingly, gas can be quickly discharged from the battery module 100, and effects such as heat generation prevention of the battery module 100 can be achieved.

On the other hand, when the venting part 220 for communicating the inside and outside of the module frame 200 is provided as in the present embodiment, dust and impurities outside the module frame 200 may pass through the hole structure of the venting part 220. It can come into the module frame 200 through. In addition, when the module frame 200 internally ignites, a phenomenon in which external oxygen is supplied along the vent 220 to promote internal ignition may occur. Accordingly, it may be desirable to provide a separate member for closing the hole in the venting part 220 .

Hereinafter, a battery module according to another embodiment of the present invention will be described. The battery module 100 described below is similar to the content of the above-described embodiments except that the barrier layer 230 is provided on the module frame 200 . Therefore, detailed descriptions of the contents overlapping with those described above will be omitted. Meanwhile, as described above, the venting portion 220 may also be formed in the end plate 400, and the barrier layer 230 described below may be provided to cover the hole formed in the end plate 400. make clear in advance

11 is a cross-sectional view showing a battery module according to another embodiment of the present invention. FIG. 12 is a view showing a state of the battery module of FIG. 11 when internally ignited. FIG. 13 is an enlarged view of portion P in FIG. 11 .

Referring to FIG. 11 , the battery module 100 according to an embodiment of the present invention may include a barrier layer 230 covering the opening of the hole structure of the vent 220 .

Here, the expression 'barrier layer' is intended to express the form of a film for blocking the hole of the venting part 220, so it may be used as a cover, a stopper, a hood, a lid, a cap or the like. It is made clear in advance that it can be expressed by changing to other words.

The barrier layer 230 may be provided in a plate shape to cover the hole of the vent 220 . The barrier layer 230 may be provided in the form of a pad to cover the hole of the venting part 220 . The barrier layer 230 may cover the hole of the venting part 220 by being disposed to cover the inlet 220a or the outlet 220b.

The barrier layer 230 may be positioned under one surface of the module frame 200 or the end plate 400 on which the vent 220 is formed. For example, as shown in FIG. 11 , the barrier layer 230 may be positioned between the upper surface of the battery cell stack 120 and the upper surface of the module frame 200 . As another example, the barrier layer 230 may be positioned between the side of the battery cell stack 120 and the side of the module frame 200 when the vent 220 is formed on the side of the module frame 200. . As another example, when the venting portion 220 is formed on the end plate 400, the barrier layer 230 may be positioned between the front or rear surface of the battery cell stack 120 and the end plate 400. . Here, for convenience of assembly, the barrier layer 230 may be attached to the inner surface 200a of the module frame 200 or the inner surface of the end plate 400, but this is not necessarily the case.

The barrier layer 230 may be provided in the sub-space. In the battery module 100 , a vent 220 may be formed in the subspace, and the barrier layer 230 may be disposed to correspond to the vent 220 . Here, the venting part 220 may be formed in each sub space divided by the spacer 210 , and the barrier layer 230 may also be provided in each sub space divided by the spacer 210 . Here, the venting part 220 and the barrier layer 230 provided in each sub-space may be described as including those formed on the end plate 400 as well as those formed on the module frame 200 .

Meanwhile, the barrier layer 230 generally closes the hole of the venting part 220 to prevent external oxygen, dust or impurities from entering the battery module 100, but internal ignition of the battery module 100 occurs. At this time, the hole of the venting part 220 may be opened.

The barrier layer 230 may be made of a material that can withstand a high temperature and high pressure environment for a certain period of time. For example, the barrier layer 230 may be made of heat-resistant plastic, CFRP (Carbon Fiber Reinforced Plastic), GFRP (Glass Fiber Reinforced Plastics), Mica-based material, or Ceramic-based material. The barrier layer 230 may be an injection molding material that can withstand a high temperature and high pressure environment for a certain period of time. For another example, the barrier layer 230 may be a silicon pad made of silicon.

The barrier layer 230 may include a material that is melted by the internal temperature of the battery module 100 . The barrier layer 230 may include a material that is melted by heat, high-temperature gas, or sparks emitted from the battery cell 110 . The barrier layer 230 may be made of a material having a melting point below a predetermined range. The barrier layer 230 may be provided with a material having a melting point of 300 °C or less. For example, the barrier layer 230 may include a thermoplastic polymer resin having a melting point of about 200 °C or less. More specifically, the barrier layer 230 may be made of materials having a melting point of about 100 °C or more and about 200 °C or less, such as polyethylene or polypropylene.

The barrier layer 230 may include a material for mitigating an ignition phenomenon when the battery module 100 internally ignites. For example, the barrier layer 230 may include a fire extinguishing agent. When the barrier layer 230 contains the extinguishing agent, the battery module 100 may have a self-extinguishing function. Here, the fire extinguishing agent may be a powdered fire extinguishing agent material. The fire extinguishing agent may generate carbon dioxide and water vapor through a thermal decomposition reaction when the battery module 100 internally ignites, and the generated carbon dioxide and water vapor prevent external oxygen from entering the battery module 100, thereby suppressing the flame. can do. The fire extinguishing agent can absorb heat generated in the battery module by performing a thermal decomposition reaction, which is an endothermic reaction, and can also block external oxygen supply by generating carbon dioxide and water vapor. Accordingly, the flame and heat propagation speed inside the battery module 100 can be effectively delayed, and the safety of the battery module can be improved.

The barrier layer 230 may include one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates. More specific examples of the extinguishing agent material may be sodium bicarbonate (NaHCO3), potassium hydrogen carbonate (KHCO3), ammonium phosphate (NH4H2PO3), and mixtures of “potassium hydrogen carbonate (KHCO3) and urea ((NH2)2CO)”. . When the barrier layer 230 includes potassium hydrogen carbonate (KHCO 3 ), potassium carbonate (K 2 CO 3 ), water vapor (H 2 O), and carbon dioxide (CO 2 ) may be generated through a thermal decomposition reaction of potassium hydrogen carbonate. The generated water vapor offsets the flame inside the battery module 100, and the generated carbon dioxide can block contact of the flame with oxygen or the like. However, the fire extinguishing agent material of this embodiment is not limited thereto, and any material that performs a fire extinguishing function may be used without limitation.

As such, the barrier layer 230 may be manufactured and provided with materials having the above-described physical properties, but may also be provided with a material having a plurality of properties or a composite of materials including each property. For example, the barrier layer 230 may be provided to include a material that can withstand a high-pressure environment for a certain period of time and has a melting point of about 300 °C or less. As another example, the barrier layer 230 may be provided as a silicone pad containing an extinguishing agent. As another example, the barrier layer 230 may be provided with a thermoplastic polymer resin containing a fire extinguishing agent.

Referring to FIG. 12 , when flames, gases or sparks are generated inside the battery module 100, specifically, some of the battery cells 110, the barrier layer 230 around the ignition phenomenon is physically damaged by heat or pressure. It may be torn or chemically melted and penetrated (penetrating), and thus the hole of the venting part 220 may be opened. Heat, gas, or spark inside the battery module 100 can be discharged through the open vent 220, and ignition of the battery module 100 can be alleviated. Here, a process in which the barrier layer 230 is pierced, ie, opened, may be accompanied by an endothermic reaction, and as the barrier layer 230 absorbs internal heat, the temperature inside the battery module 100 may be somewhat lowered. Heat, gas, etc. emitted to the outside of the venting unit 220 through an endothermic reaction of the barrier layer 230 may lose energy enough not to affect the adjacent battery module 100, and the spark loses energy and changes into particles. Therefore, the thermal runaway phenomenon of adjacent battery modules 100 may not be promoted. Meanwhile, in the foregoing, the effect of the barrier layer 230 has been mainly described based on the fact that the barrier layer 230 is opened through a chemical reaction. However, even when the barrier layer 230 is physically opened by pressure or the like, since the kinetic energy of gas or spark inside the barrier layer 230 is reduced, heat, gas, etc. emitted to the outside of the venting unit 220 Energy may be lost so as not to affect adjacent battery modules 100, and sparks may lose energy and be changed into particles so that thermal runaway of adjacent battery modules 100 may not be promoted.

Since the barrier layer 230 can be opened only when heat or pressure of a predetermined range or higher is applied, only the venting parts 220 located around where ignition occurs can be individually opened. The barrier layer 230 may prevent thermal runaway from accelerating due to additional oxygen inflow by opening only some of the plurality of vents 220 .

Specifically, when a plurality of venting parts 220 are formed in a sub-space and the barrier layer 230 is positioned to correspond to the venting part 220, the first battery cell 110 located in one sub-space is ignited. When the phenomenon occurs, the first portion of the barrier layer 230 located in the subspace may be pierced, and accordingly, flames generated by opening the venting part 220 may be discharged. At this time, since only the first part is removed from the barrier layer 230, the first venting part 220 corresponding to the first part is opened, but other venting parts 220 in the sub-space may not be open. have. That is, the second part of the barrier layer 230 located on top of the second battery cell 110 where no ignition phenomenon has occurred in the subspace may not be opened and corresponds to the second part of the venting part 220. The second venting part 220 may be in a closed state. As such, other than some of the vents 220 formed in the sub-space, the other vents 220 are closed by the barrier layer 230, so that additional inflow of external oxygen into the sub-space is blocked. and the amplification of flames generated inside the subspace by the introduced oxygen can be suppressed.

Meanwhile, in FIGS. 11 and 12 described above, the barrier layer 230 is shown to be located at the inlet 220a of the venting part 220, but the barrier layer 230 fills the hole of the venting part 220, Likewise, it may be provided in the form of a stopper filling the inner space of the hole of the venting part 220 . In addition, the barrier layer 230 includes a first barrier layer filling the hole of the venting part 220 and a second barrier layer formed on the inner surface of the module frame 200 where the inlet 220a of the venting part 220 is located. may be provided to do so. When the barrier layer 230 is provided having a first barrier layer and a second barrier layer, the space occupied by the barrier layer 230 inside the battery module 100 is the same, but the venting portion 220 of the battery module 100 Since the two layers of the barrier layer 230 must be opened to open, the fire suppression effect by the barrier layer 230 may be greater. Here, the first layer and the second layer may be integrally configured in a combined state, but this is not necessarily the case, and may be provided separately in a separated state.

Referring to FIGS. 11 and 13 , the venting part 220 described in this embodiment may be formed on the top of the module frame 200 facing the sealing part 110a. The sealing portion 110a corresponds to the sealing portion 114sc formed on one side portion 114c connecting both ends 114a and 114b of the cell case 114 to each other in the battery cell 110 described in FIG. The portion 114sc may be formed in the longitudinal direction of the battery cell. In FIG. 13 , a structure in which the sealing portion 110a is folded several times may be shown.

Meanwhile, the battery module 100 described above may be included in a battery pack. The battery pack may include one or more battery modules according to the present embodiment, and may have a structure in which a battery management system (BMS) for managing temperature or voltage of the battery, a cooling device, and the like are added and packed. .

A battery module and a battery pack including the battery module may be applied to various devices. Such a device may be applied to means of transportation such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present invention is not limited thereto and is applicable to various devices capable of using a battery module and a battery pack including the battery module, which is also applicable to the present invention. It belongs to the scope of the right of invention.

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 of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

100: battery module
110: battery cell
110a: sealing part
111, 112: electrode lead
120: battery cell stack
200: module frame
210: separation member
220: venting part
230: barrier layer

Claims (15)

A battery cell laminate in which a plurality of battery cells are stacked in one direction,
A module frame accommodating the battery cell stack and having an inner surface and an outer surface, and
An end plate coupled to the module frame and covering the front or rear surface of the battery cell stack,
Inside the module frame, a first cell assembly including at least one battery cell of the battery cell stack, and a first cell assembly adjacent to the first cell assembly and including at least one battery cell of the battery cell stack A two-cell assembly is placed,
A battery module in which a separation member is positioned to isolate the first cell assembly and the second cell assembly from each other. According to claim 1,
The spacer member extends from the top and bottom of the module frame and is provided in the form of a barrier rib between the first cell assembly and the second cell assembly. According to claim 2,
The module frame and the spacer member are integral battery module. According to claim 1,
The module frame includes at least two subspaces separated by the spacer, and each of the subspaces has a hole shape defining an inlet formed on an inner surface of the module frame and an outlet formed on an outer surface of the module frame. A battery module in which at least one venting part is formed. According to claim 4,
The battery module wherein the venting portion is formed on the upper portion of the module frame. According to claim 5,
The battery cell includes an electrode assembly and a cell case accommodating the electrode assembly,
The electrode assembly is sealed by the sealing part of the cell case,
The sealing part of the cell case is formed on one side connecting both ends of the cell case to each other,
The battery module wherein the sealing portion is formed in the longitudinal direction of the battery cell. According to claim 4,
The discharge direction of the venting part forms an acute angle with one surface of the module frame on which the venting part is formed,
The discharge direction of the venting unit is a direction from the inlet toward the outlet of the battery module. According to claim 4,
The battery module wherein the hole of the venting portion is covered by a barrier layer. According to claim 8,
The barrier layer is a battery module comprising a material having a melting point of about 300 ℃ or less. According to claim 8,
The barrier layer is a battery module containing heat-resistant plastic, CFRP (Carbon Fiber Reinforced Plastic), GFRP (Glass Fiber Reinforced Plastics), Mica-based material, Ceramic-based material, or silicon. According to claim 8,
The battery module of claim 1 , wherein the barrier layer includes at least one extinguishing agent selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates. According to claim 8,
The barrier layer is a battery module located between one surface of the module frame on which the venting portion is formed and the battery cell laminate. According to claim 8,
The barrier layer is a battery module that fills the inner space of the hole of the venting part. According to claim 8,
The barrier layer includes a first barrier layer filling the inner space of the hole of the venting part and a second barrier layer positioned between one surface of the module frame on which the venting part is formed and the battery cell stack. A battery pack comprising at least one battery module according to claim 1 .

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