KR20240083793A - Battery module, battery pack and vehicle comprising the same - Google Patents

Abstract

The present invention discloses a battery module with enhanced safety. A battery module according to one aspect of the invention includes a cell stack including a plurality of battery cells stacked in at least one direction; and a module case configured to accommodate the cell stack, wherein at least one of the plurality of battery cells has a coating layer on its surface.

Description

Battery module, battery pack and vehicle comprising the same}

The present invention relates to a battery module, a battery pack including the same, and a vehicle. More specifically, it relates to a battery module with enhanced safety, a battery pack including the same, and a vehicle.

As the demand for portable electronic products such as laptops, video cameras, and portable phones is rapidly increasing, and the commercialization of robots and electric vehicles is in full swing, research on high-performance secondary batteries capable of repeated charging and discharging is actively underway.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries have little memory effect compared to nickel-based secondary batteries, so they can be freely charged and discharged. It is receiving attention for its extremely low self-discharge rate and high energy density.

These lithium secondary batteries mainly use lithium-based oxide and carbon material as positive and negative electrode active materials, respectively. A lithium secondary battery includes an electrode assembly in which positive and negative electrode plates each coated with the positive and negative electrode active materials are disposed with a separator in between, and an exterior material, that is, a battery case, that seals and stores the electrode assembly together with an electrolyte.

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

Recently, secondary batteries have been widely used for driving or energy storage not only in small devices such as portable electronic devices, but also in medium to large devices such as electric vehicles and energy storage systems (ESS). A plurality of these secondary batteries can be electrically connected and stored together inside a module case to form one battery module. Additionally, a plurality of these battery modules can be connected to form one battery pack.

However, when a large number of secondary batteries (battery cells) or a large number of battery modules are crowded in a small space, they may be vulnerable to thermal events. In particular, when a thermal event occurs in one battery cell, heat, flame, sparks, etc. may be generated. If this heat is transferred to other battery cells, an explosive chain reaction such as thermal propagation (TP) may occur, which may cause explosion or ignition in the battery module.

Moreover, in the case of medium to large battery packs such as electric vehicles, a large number of battery cells and battery modules are included to increase output and/or capacity, and there may be users such as drivers nearby, raising the risk of thermal chain reaction. It can get bigger.

Therefore, when a thermal event occurs in a specific battery cell or battery module, there is a need for a method to improve safety by delaying heat transfer to other battery cells or battery modules.

The present invention was created to solve the above problems, and its purpose is to provide a battery module whose safety can be improved through heat transfer delay, etc., and a battery pack and automobile including the same.

Another problem to be solved by the present invention is to provide a battery pack with improved stability by including such a battery module and a vehicle including the same.

However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

A battery module according to an aspect of the present invention for solving the above problems includes a cell stack including a plurality of battery cells stacked in at least one direction; and a module case configured to accommodate the cell stack.

At least one of the plurality of battery cells may have a coating layer on its surface.

The coating layer may be coated on the entire surface of the battery cell.

The coating layer may be provided on the surface of each battery cell included in the cell stack.

The cell stack may include a swelling absorption pad disposed between the plurality of battery cells.

Each of the two battery cells located on both sides of the swelling absorption pad may be provided with the coating layer at a corresponding position.

The coating layer may be a fire-resistant coating layer.

The coating layer may include a silica material.

The swelling absorption pad may be disposed between adjacent battery cells.

The swelling absorption pad may be a thermal pad having elasticity and heat resistance.

The swelling absorption pad may include silicone.

The swelling absorption pad may have an area larger than the surface facing the battery cell.

The battery pack according to the present invention may include a battery module according to the present invention.

A vehicle according to the present invention may include a battery pack according to the present invention.

According to one aspect of the present invention, the swelling absorption pad can absorb or suppress the pressure generated by the swelling phenomenon of the battery cell. Acceleration of thermal runaway caused by swelling can be prevented. It is possible to delay or prevent a thermal chain reaction in which flame and/or heat generated by a thermal event occurring in a specific battery cell moves to other adjacent battery cells.

In particular, in the case of pouch-type secondary batteries, they may be relatively vulnerable to flame and/or heat, etc. compared to can-type batteries due to the nature of the packaging material, but according to the present invention, a coating layer is formed on the surface of the pouch packaging material, thereby delaying or preventing the above thermal chain reaction. The effect may be increased.

According to another aspect of the present invention, the swelling absorption pad can more effectively absorb or suppress the pressure generated by the swelling phenomenon of the battery cell. This is because the swelling absorption pad is accommodated in the receiving portion of the module case and bus bar frame and is stably fixed.

1 is a diagram showing the appearance of a battery module according to the present invention.
Figure 2 is an exploded perspective view of a battery module according to the present invention.
Figure 3 is a diagram showing a battery cell included in a battery module according to the present invention.
FIG. 4 is a diagram showing an exemplary cross section cut along line BB' in FIG. 3.
Figure 5 is a diagram showing a swelling absorption pad included in a battery module according to the present invention and two battery cells located on both sides of the swelling absorption pad.
FIGS. 6 and 7 are diagrams illustrating exemplary cross-sections taken along line AA′ of FIG. 1 .
Figure 8 is a diagram showing a bus bar assembly included in the battery module according to the present invention.
Figure 9 is a diagram showing a battery pack according to the present invention.
Figure 10 is a diagram showing a vehicle according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention described later, so the present invention is limited only to the matters described in such drawings. It should not be interpreted as such. Identical reference numerals refer to identical elements. Additionally, in the drawings, the thickness, proportions and dimensions of components are exaggerated for effective explanation of technical content.

Terms or words used in this specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

In this specification, terms indicating directions such as up, down, left, right, front, and back are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer. is obvious to those skilled in the art of the present invention.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical details of the present invention, so at the time of filing the present application, various options that can replace them are available. It should be understood that equivalents and variations may exist.

1 is a diagram showing the appearance of a battery module according to the present invention. Figure 2 is an exploded perspective view of a battery module according to the present invention. Figure 3 is a diagram showing a battery cell included in a battery module according to the present invention. FIG. 4 is a diagram showing an exemplary cross section taken along line B-B' in FIG. 3.

Referring to FIGS. 1 to 4 , the battery module 10 according to the present invention may include a cell stack 100 and a module case 200.

The cell stack 100 may include a plurality of battery cells 110 stacked in at least one direction.

Each battery cell 110 may represent a secondary battery. The battery cell 110 may include an electrode assembly, an electrode lead 113 connected to the electrode assembly, and a battery case that accommodates the electrode assembly and is sealed so that the electrode lead 113 is pulled out. An electrolyte may be accommodated inside the battery case. In particular, the battery cell 110 provided in the cell stack 100 may be a pouch-type secondary battery. The cell stack 100 may have a plurality of pouch-type secondary batteries arranged side by side in the horizontal direction so that their large surfaces face each other in an upright state.

At least one of the plurality of battery cells 110 may have a coating layer (C) on its surface. The coating layer (C) may be coated on the entire surface of the battery cell 110. The coating layer (C) may be provided on the surface of each battery cell 110.

The battery case may include an accommodating portion 111 that accommodates the electrode assembly, and a sealing portion 112 extending outward from the circumference of the accommodating portion 111 to seal the accommodating portion 111. The coating layer (C) may be provided on the entire remaining surface of the battery cell 110 except for the electrode lead 113. That is, the coating layer (C) may be configured to cover both the receiving part 111 and the sealing part 112 of the pouch case. In this way, when the coating layer (C) is provided on the entire area of the battery cell 110 except for the electrode lead 113 for electrical connection, the fire resistance performance of the battery cell 110 itself is improved without affecting the electrical connection. You can do it.

In another aspect, the coating layer (C) may also be provided on a part of the electrode lead 113. The coating layer (C) may be configured to cover the entire area of the electrode lead 113 excluding the surface that is coupled to other components (e.g., bus bars, electrode leads of adjacent battery cells, terminals, etc.). there is. In this case, the fire resistance performance of the battery cell 110 can be further improved. However, the present invention is not limited to this, and the coating layer (C) may be provided only in the receiving portion 111 of the pouch case.

The coating layer (C) may be formed by applying paint to the surface of the battery cell 110 using a spray method. However, in addition to this, the coating layer (C) may be provided on the surface of the battery cell 110 in various other ways.

The coating layer (C) may be a fire-resistant coating layer (C). The coating layer (C) may include a silica material. The coating layer (C) may include an alumina material. The coating layer (C) may include a magnesia material.

The swelling absorption pad 120 may be disposed between the plurality of battery cells 110 . The swelling absorption pad 120 may be disposed between two adjacent battery cells 110 . The swelling absorption pad 120 may be disposed between two adjacent battery cells 110 . The swelling absorption pad 120 may be configured in a plate shape.

The swelling absorption pad 120 may be made of an elastic material. The swelling absorption pad 120 may be made of a heat-resistant material that can withstand flame or heat above a certain level. The swelling absorption pad 120 may include a polyurethane material. The swelling absorption pad 120 may include a silicone material.

According to this configuration of the present invention, the swelling absorption pad 120 can absorb or suppress the pressure generated by the swelling phenomenon of the battery cell 110. In another aspect, according to this configuration of the present invention, it is possible to prevent the problem of acceleration of thermal runaway phenomenon due to swelling phenomenon. In another aspect, according to this configuration of the present invention, it is possible to delay or prevent a thermal chain reaction in which flame and/or heat generated due to a thermal event occurring in a specific battery cell 110 moves to other adjacent battery cells 110. You can.

In particular, in the case of pouch-type secondary batteries, they may be relatively vulnerable to flame and/or heat, etc. compared to can-type batteries due to the nature of the packaging material. However, according to the present invention, a coating layer (C) is formed on the surface of the pouch packaging material, thereby causing the above thermal chain reaction. Delay or prevention effects may be increased.

The module case 200 may be configured to accommodate the cell stack 100. The module case 200 may be configured to have an accommodating space capable of accommodating the cell stack 100. The module case 200 has a case body 210 consisting of four covers forming each side in the form of an approximately four-cornered pillar, and a pair of end covers 220 that cover the front and back of the cell stack 100. It can be included.

Figure 5 is a diagram showing a swelling absorption pad included in a battery module according to the present invention and two battery cells located on both sides of the swelling absorption pad.

Referring to FIG. 5, each of the two battery cells 110 located on both sides of the swelling absorption pad 120 may be provided with a coating layer C at a corresponding position.

Referring to FIG. 5 , the swelling absorption pad 120 may have a larger area than the facing surface of the battery cell 110 .

When the battery case provided in the battery cell 110 includes an accommodating portion 111 for accommodating the electrode assembly and a sealing portion 112 for sealing the accommodating portion 111, the swelling absorption pad 120 is provided on both sides. The two battery cells 110 located may have a coating layer (C) in the area corresponding to the receiving portion 111. The swelling absorption pad 120 may have a correspondingly larger area than the receiving portion 111. The swelling absorption pad 120 may be configured to cover the entire receiving portion 111.

FIGS. 6 and 7 are diagrams showing exemplary cross-sections taken along line A-A' in FIG. 1.

Referring to FIGS. 6 and 7 , the module case 200 may include a first accommodating portion 201 in which the swelling absorption pad 120 is accommodated. The module case 200 may be provided with a first receiving portion 201 on the inner surface of the case body 210.

Referring to FIG. 6 , the first receiving portion 201 may be provided at a position corresponding to the swelling absorption pad 120. The first receiving portion 201 may be provided on the inner surface of at least one of the upper and lower portions of the module case 200. The first accommodating portion 201 may be in the form of a groove extending approximately in a straight line from one end of the module case 200 to the other end. The first receiving portion 201 may be provided to correspond to the number of swelling absorption pads 120 .

According to this configuration of the present invention, the swelling absorption pad 120 can more effectively absorb or suppress the pressure generated by the swelling phenomenon of the battery cell 110. This is because the swelling absorption pad 120 is accommodated in the first receiving portion 201 of the module case 200 and is stably fixed. In another aspect, according to this configuration, thermal propagation between adjacent battery cells 110 can be more effectively prevented. This is because an empty space can be prevented from being formed between the swelling absorption pad 120 and the inner surface of the module housing 200.

In addition, referring to FIG. 2, when an assembly of the cell stack 100 and the swelling absorption pad 120 is accommodated in the module case 200, the swelling absorption pad 120 is placed in the first receiving portion. (201) After accommodating only a portion at one end, the entire body can be accommodated in a sliding manner by moving towards the other end.

Referring to FIG. 7 , the battery module 10 may include an additional swelling absorption pad 121 disposed between the cell stack 100 and the module case 200. The battery module 10 is located between the left side (X-axis negative direction) of the cell stack 100 and the inner side of the left side (X-axis negative direction) of the module case 200 and the right side (X-axis direction) of the cell stack 100. It may include two additional swelling absorption pads 121 between the inner side (positive direction of axis) and the right side (positive direction of X-axis) of the module case 200. The module case 200 may be provided with a second receiving portion 202 in which the additional swelling absorption pad 121 is accommodated. The second receiving portion 202 may be provided at a position corresponding to the additional swelling absorption pad 121. In this case, the first receiving portion 201 may be provided selectively.

According to this configuration of the present invention, the additional swelling absorption pad 121 delays the thermal chain reaction in which flame and/or heat generated due to the thermal runaway phenomenon occurring in the battery cell 110 moves to the module case 200. Or it can be prevented. Referring to Figure 2 together, when an assembly of the cell stack 100, the swelling absorption pad 120, and the additional swelling absorption pad 121 is accommodated in the module case 200, the additional swelling absorption pad (121) can be accommodated in its entirety in a sliding manner by partially accommodating one end of the second accommodating portion 202 and then moving it toward the other end.

Figure 8 is a diagram showing the bus bar assembly 400 included in the battery module 10 according to the present invention.

Referring to FIG. 8 , the battery module 10 may include a busbar assembly 400.

The bus bar assembly 400 may include a bus bar 420 that electrically connects the plurality of battery cells 110 and a bus bar frame 410 on which the bus bar 420 is seated.

The bus bar frame 410 may include a bus bar seating portion 411, an electrode lead accommodating portion 412 in which the electrode lead 113 is accommodated, and a third accommodating portion 413.

Referring to FIG. 2 , the third accommodating portion 413 may accommodate one end of the swelling absorption pad 120 in the longitudinal direction (Y-axis extension direction). The third receiving portion 413 may be a groove extending along the height direction (Z-axis extension direction) of the bus bar frame 410. The third receiving portion 413 may be provided on the inner surface of the bus bar frame 410. The third receiving portion 413 may be in the form of a groove indented from the substantially flat inner surface of the bus bar frame 410 toward the positive Y-axis direction to correspond to the shape of the swelling absorption pad 120. The third receiving portion 413 may be in the form of a groove indented in the positive Y-axis direction to correspond to the shape of the swelling absorption pad 120 from a protrusion formed in a substantially trapezoidal column shape on the inner surface of the bus bar frame. . However, the third receiving portion 413 may be configured not only in the form of a groove, but also in the form of a hole so that the swelling absorption pad 120 passes through it.

According to this configuration of the present invention, the swelling absorption pad 120 is more stable not only by the first accommodating part 201 of the module case 200, but also by the third accommodating part 413 of the bus bar frame 410. can be fixed.

Figure 9 is a diagram showing a battery pack according to the present invention.

Referring to FIG. 9, the battery pack 2 may include one or more battery modules 10 according to the present invention described above. In addition, the battery pack 2 according to the present invention includes various other components in addition to the battery module 10, such as a BMS, a bus bar, a pack case, a relay, a current sensor, etc. known at the time of filing the present invention. It may further include components of the battery pack 2, etc.

Figure 10 is a diagram showing a vehicle according to the present invention.

Referring to FIG. 10, the automobile 1 may include one or more battery packs 2 according to the present invention described above. In addition, the automobile 1 according to the present invention may further include various other components included in the automobile 1 in addition to the battery pack 2. For example, the automobile 1 according to the present invention may further include a vehicle body, a motor, and a control device such as an ECU (electronic control unit) in addition to the battery pack 2 according to the present invention.

As described above, the present invention has been described with reference to the accompanying drawings, focusing on preferred embodiments, but it is clear to those skilled in the art that many obvious modifications can be made from this description without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed by the appended claims to include examples of many such modifications.

1: car
2: Battery pack
10: Battery module
100: Cell laminate
110: battery cell
111: Receiving part
112: Sealing part
113: electrode lead
120: Swelling absorption pad
121: Additional swelling absorbent pad
200: module case
201: first receiving part
202: second receiving part
210: Case body
220: end cover
400: Busbar assembly
410: Busbar frame
411: Bus bar seating part
412: Electrode lead receiving portion
413: third receiving part
420: bus bar
Coating layer C

Claims (13)

A cell stack including a plurality of battery cells stacked in at least one direction; and
A module case configured to accommodate the cell stack;
In the battery module containing,
At least one of the plurality of battery cells,
A battery module characterized by having a coating layer on the surface. According to claim 1,
The coating layer is,
A battery module characterized in that the entire surface of the battery cell is coated. According to claim 1,
The coating layer is,
A battery module, characterized in that it is provided on the surface of each battery cell included in the cell stack. According to claim 1,
The cell stack is,
A battery module comprising a swelling absorption pad disposed between the plurality of battery cells. According to clause 4,
Each of the two battery cells located on both sides of the swelling absorption pad,
A battery module, characterized in that the coating layers are provided at positions corresponding to each other. According to claim 1,
The coating layer is,
A battery module characterized by a fire-resistant coating layer. According to claim 1,
The coating layer is,
A battery module comprising a silica material. According to clause 4,
The swelling absorption pad,
A battery module characterized in that it is disposed between adjacent battery cells. According to clause 4,
The swelling absorption pad,
A battery module characterized by a thermal pad having elasticity and heat resistance. According to clause 4,
The swelling absorption pad,
A battery module comprising silicon. According to clause 4,
The swelling absorption pad,
A battery module, characterized in that it has an area larger than the facing surface of the battery cell. A battery pack comprising the battery module according to any one of claims 1 to 11. An automobile comprising a battery pack according to claim 12.

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