KR20230170556A - Battery pack and vehicle including the same - Google Patents

Abstract

A battery pack and a vehicle including the same are disclosed. A battery pack according to an embodiment of the present invention includes a plurality of pouch-type battery cells; A pack case that stores pouch-type battery cells in an internal space; and a cell cover provided to at least partially surround at least some of the pouch-type battery cells among the plurality of pouch-type battery cells in the inner space of the pack case, and having a deformed straight portion formed on at least one side.

Description

Battery pack and vehicle including the same {BATTERY PACK AND VEHICLE INCLUDING THE SAME}

The present invention relates to a battery pack and a vehicle including the same, and more specifically, to a battery pack with improved stability and a vehicle including the same.

As technology development and demand for various mobile devices, electric vehicles, energy storage systems (ESS), etc. increase significantly, interest in and demand for secondary batteries as an energy source are rapidly increasing.

Conventionally, nickel-cadmium batteries or nickel-hydrogen batteries were widely used as secondary batteries, but recently, lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries, allowing for free charging and discharging, a very low self-discharge rate, and high energy density. Batteries are widely used.

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 a positive electrode plate and a negative electrode plate coated with the positive electrode active material and the negative electrode active material 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 solution.

In general, secondary batteries can be classified into can-type batteries in which the electrode assembly is built into a metal can and pouch-type 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, battery packs have been widely used for driving or energy storage in medium to large-sized devices such as electric vehicles or energy storage systems.

A conventional battery pack includes one or more battery modules inside a pack case and a control unit that controls charging and discharging of the battery pack. Here, the battery module is configured to include a plurality of battery cells inside a module case.

That is, in the case of a conventional battery pack, a plurality of battery cells (secondary batteries) are stored inside a module case to form each battery module, and one or more of these battery modules are stored inside the pack case to form a battery pack.

In particular, pouch-type batteries have advantages in many aspects, such as being light in weight and requiring less dead space when stacked, but they are vulnerable to external shocks and have somewhat poor assembly properties.

Therefore, it is common for battery packs to be manufactured by first modularizing a number of cells and then storing them inside a pack case.

However, in the case of conventional battery packs, they may be disadvantageous in terms of energy density, assembly, cooling, etc. due to modularization. In particular, in the case of pouch-type battery cells, swelling may occur, and conventional battery packs have a problem in that it is difficult to appropriately respond to such swelling situations.

Additionally, conventional battery packs may be disadvantageous in terms of energy density, assembly, cooling, etc. due to modularization.

Additionally, conventional battery packs or battery modules may be vulnerable to thermal events. In particular, if a thermal event occurs inside a battery module or battery pack, thermal runaway may occur, resulting in flames and, in severe cases, explosion.

Accordingly, the present invention was created to solve the above problems, and its purpose is to provide a battery pack that is excellent in various aspects such as swelling response performance and a vehicle including the same.

Additionally, the goal is to provide a battery pack that can ensure excellent safety in the event of a thermal event 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 will be clearly understood by those skilled in the art from the description of the invention described below.

According to one aspect of the present invention, a plurality of pouch-type battery cells; a pack case storing the pouch-type battery cells in an internal space; and a cell cover provided to at least partially surround at least some of the pouch-type battery cells among the plurality of pouch-type battery cells in the inner space of the pack case, and having a deformable straight portion formed on at least one side. there is.

In one embodiment, the deformed straight portion may be formed in a corrugated structure on the upper side of the cell cover and be configured to unfold when the pouch-type battery cell is expanded.

In one embodiment, the deformed straight portion may have a wave pattern shape in which side portions on both sides protrude toward the top and central portions connected to both side portions are concave toward the bottom.

In one embodiment, the cell cover is provided in multiple numbers, an discharge hole is formed on at least one side of the pack case, the deformed straight portion is configured to change in length in the width direction, and the width direction of the cell cover is The communication area with the discharge hole can be varied by changing the length.

In one embodiment, the discharge holes of the pack case may be formed long or formed in multiple numbers along the arrangement direction of the plurality of cell covers.

In one embodiment, the deformed straight portion may be formed on an upper side of the cell cover, and a triangle portion folded into a triangle shape may be formed.

In one embodiment, the cell cover may include a particle pocket portion configured to be spaced apart from the pouch-type battery cell and configured to collect particles ejected from the pouch-type battery cell when a thermal event occurs.

In one embodiment, the particle pocket portion may be configured so that side portions on both sides along the width direction of the cell cover protrude more toward the top than the center portion.

In one embodiment, a mesh member may be formed inside the particle pocket portion.

In one embodiment, a directional venting portion may be formed on the cell cover to guide venting gas and discharge it in a preset direction.

In one embodiment, it includes a thermal resin coupled to the cell cover, wherein the cell cover has a portion to which the thermal resin is coupled and a portion to which the thermal resin is not bonded, and the directional venting portion includes the a gas exhaust port formed in a portion of the cell cover to which the thermal region is not coupled; And it may include a moving passage formed between the pouch-type battery cell and the cell cover.

In one embodiment, the cell cover may be configured to partially surround the pouch-type battery cell so that at least one side of the wrapped pouch-type battery cell is exposed to the outside.

In one embodiment, the cell cover may be configured so that at least one side of the wrapped pouch-type battery cell is exposed toward the bottom of the battery pack.

In one embodiment, the cell cover may be directly mounted on the pack case.

Meanwhile, according to another aspect of the present invention, a vehicle including the above-described battery pack can be provided.

Embodiments of the present invention have excellent effects in many aspects, such as swelling response performance.

Additionally, it has the effect of ensuring excellent safety when a thermal event occurs.

The following 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 includes the matters described in such drawings. It should not be interpreted as limited to only .
1 is a schematic exploded perspective view of a battery pack according to a first embodiment of the present invention.
Figures 2 to 4 are diagrams illustrating a process in which a cell cover is coupled to a pouch-type battery cell stored inside a battery pack according to the first embodiment of the present invention and two pouch-type battery cells are connected to a bus bar.
Figure 5 is a cross-sectional view of a pouch-type battery cell stored inside a battery pack according to the first embodiment of the present invention.
FIG. 6 is a diagram illustrating a state in which swelling occurs in FIG. 5 and the wrinkled cell cover is unfolded.
Figure 7 is a cross-sectional view showing two pouch-type battery cells stored in one cell cover according to a modified embodiment of Figure 5.
Figure 8 is a cross-sectional view of a pouch-type battery cell stored inside a battery pack according to a second embodiment of the present invention.
FIG. 9 is a diagram illustrating a process in which the length of a cell cover changes according to expansion and contraction of the pouch-type battery cell of FIG. 8.
Figure 10 is a diagram schematically showing the pack case configuration of a battery pack according to a second embodiment of the present invention.
FIG. 11 is a diagram showing a modified embodiment of FIG. 8.
Figure 12 is an exploded perspective view of a pouch-type battery cell and a cell cover stored inside a battery pack according to a third embodiment of the present invention.
FIG. 13 is a cross-sectional view of the pouch-type battery cell of FIG. 12 combined with the cell cover.
FIG. 14 is a partial perspective view of the pouch-type battery cell of FIG. 12 combined with the cell cover, showing a gas exhaust port.
FIG. 15 is a side cross-sectional view of the pouch-type battery cell of FIG. 12 combined with the cell cover, showing a directional venting portion that is an exhaust path for gas.
Figure 16 is a diagram for explaining a vehicle including a battery pack according to each embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms or words used in this specification and claims should not be construed as limited to their common 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. 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 the entire technical idea of the present invention, so at the time of filing the present application, various alternatives may be used to replace them. It should be understood that equivalents and variations may exist.

In the drawings, the size of each component or specific part constituting the component is exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect the actual size. If it is determined that specific descriptions of related known functions or configurations may unnecessarily obscure the gist of the present invention, such descriptions will be omitted.

The term 'coupling' or 'connection' used in this specification refers not only to the case where one member and another member are directly coupled or directly connected, but also when one member is indirectly coupled to another member through a joint member, or indirectly connected to another member. Also includes cases where it is connected to .

Figure 1 is a schematic exploded perspective view of a battery pack according to a first embodiment of the present invention, and Figures 2 to 4 show a cell cover on a pouch-type battery cell stored inside the battery pack according to a first embodiment of the present invention. It is a diagram showing the process of combining and connecting two pouch-type battery cells to a bus bar, FIG. 5 is a cross-sectional view of a pouch-type battery cell stored inside a battery pack according to the first embodiment of the present invention, and FIG. 6 is FIG. Figure 5 shows a state in which swelling has occurred and the wrinkled cell cover has been unfolded, and Figure 7 is a cross-sectional view showing two pouch-type battery cells stored in one cell cover as a modified example of Figure 5.

The present invention relates to a battery pack 10 in which the battery cells 100 can be directly stored in the pack case 200 of the battery pack 10 by removing the battery module.

According to this, since more battery cells 100 can be stored in the space occupied by the module case of the battery module within the battery pack 10, space efficiency is increased and battery capacity is improved. That is, in the present invention, the module case of the battery module may not be included in the configuration.

However, this does not exclude the embodiment using a module case, and if necessary, the pouch-type battery cell 100 of each embodiment of the present invention may be accommodated in the module case provided in the battery module.

That is, the battery module provided with the pouch-type battery cell 100 combined with the cell cover 300 in each embodiment of the present invention also falls within the scope of the present invention.

Also, even when simply referred to as a battery cell 100 in this specification, the battery cell 100 refers to a pouch-type battery cell 100.

Referring to FIG. 1, the battery pack 10 according to the first embodiment of the present invention includes a pouch-type battery cell 100, a pack case 200, and a cell cover 300.

The pouch-type battery cell 100 is a pouch-type secondary battery and may include an electrode assembly, an electrolyte, and a pouch exterior material. A plurality of such pouch-type battery cells 100 may be included in the battery pack 10 . And, these plurality of pouch-type battery cells 100 may be stacked in at least one direction.

The pack case 200 has an empty space inside, and pouch-type battery cells 100 can be stored in this inner space. In particular, in the present invention, the pouch-type battery cell 100 can be directly seated on the pack case 200.

Referring to FIGS. 2 to 4 , the cell cover 300 may be provided to at least partially cover the pouch-type battery cell 100. That is, the cell cover 300 may be configured to partially surround the pouch-type battery cell 100 so that at least one side of the wrapped pouch-type battery cell 100 is exposed to the outside.

The cell cover 300 may be configured to support the pouch-type battery cell 100 in an upright state. It is generally not easy to stack the pouch-type battery cells 100 in an upright direction.

However, in the battery pack 10 according to the present invention, the cell cover 300 surrounds one or more pouch-type battery cells 100 and maintains the upright state of the wrapped pouch-type battery cells 100, that is, the standing state. It can be configured to maintain.

In addition, the cell cover 300 may be configured so that at least one side of the wrapped pouch-type battery cell 100 is exposed toward the bottom surface of the battery pack 10.

And referring to FIG. 1, the cell cover 300 configured to surround at least some of the pouch-type battery cells 100 among the plurality of pouch-type battery cells 100 may be stored in the internal space of the pack case 200. .

The cell cover 300 may be configured to surround a various number of pouch-type battery cells 100 together. For example, the cell cover 300 may be configured to surround one pouch-type battery cell 100 together, as shown in FIG. 5 . Alternatively, as shown in FIG. 7, it may be configured to surround two pouch-type battery cells 100 together. Alternatively, it may be configured to surround three or more pouch-type battery cells 100 together.

Referring to FIGS. 5 and 7 , a deformed straight portion 310 may be formed on at least one side of the cell cover 300. The term deformed straight line portion 310 used in each embodiment of the present specification refers to various shapes that can be formed by deforming one straight line in a portion of the cell cover 300.

For example, in FIGS. 5 and 7 , the upper side of the cell cover 300 is not a straight shape but a wrinkled shape formed by deforming a straight line. That is, in this specification, the deformed straight part 310 refers to any shape that can be formed by deforming a straight part into a deformed straight part.

The deformed straight portion 310 may be formed in various parts of the cell cover 300, for example, on the upper side of the cell cover 300 as shown in FIGS. 5 and 7.

For example, as shown in FIGS. 5 and 7, a deformed straight portion 310 having a wavy or wrinkled shape may be formed on the upper side of the cell cover 300. Here, the deformed straight portion 310 may be formed in various sizes or shapes.

In another embodiment, the deformed straight portion 310 may be formed to extend from the top to the side of the cell cover 300.

The deformed straight portion 310 may be formed in various ways. For example, as shown in FIGS. 5 and 7, the deformed straight portion 310 may be formed in a corrugated structure, but is not limited thereto.

The wrinkled structure of the deformed straight portion 310 may be formed in a concave-convex shape. For example, the deformed straight portion 310 has side portions 311 and 313 on both sides protruding upward and the central portion 312 connected to both side portions 311 and 313 is concave toward the bottom, giving an overall wavy pattern. It can be formed to have any shape.

That is, the cell cover 300 may be concave toward the inner direction where the battery cell 100 is located and convex toward the outer direction.

Additionally, the deformable straight portion 310 may be configured to unfold when the pouch-type battery cell 100 is expanded (see FIG. 6). For example, when swelling occurs in the pouch-type battery cell 100 with reference to FIG. 5, the pouch-type battery cell 100 may expand in the thickness direction.

At this time, referring to FIG. 6 , the deformed straight portion 310 of the cell cover 300 is at least partially spread flat, thereby absorbing swelling of the pouch-type battery cell 100. Moreover, according to this implementation configuration, uniform pressure can be applied to the entire surface of the pouch-type battery cell 100, especially the outer surface of the storage portion.

Therefore, damage or breakage of the cell can be prevented because excessive pressure is not applied to any part of the cell. Additionally, in this case, the deterioration rate of the pouch-type battery cell 100 is reduced.

Referring to FIG. 1, the cell cover 300 may be directly seated on the upper surface of the pack case 200. For example, the lower end of the cell cover 300 may be seated in direct contact with the upper surface of the pack case 200.

In particular, the cell cover 300 and the pouch-type battery cell 100 can be directly seated in the pack case 200 without being stored in a separate module case. However, as described above, the embodiment in which the module is modularized by being seated in a module case is not excluded.

Accordingly, the cooling performance of the battery pack 10 can be secured more effectively. In particular, since the pouch-type battery cells 100 can be in face-to-face contact with the pack case 200, the heat emitted from each pouch-type battery cell 100 is directly transferred to the pack case 200, improving cooling performance. It can be.

The cell cover 300 may be configured to support the stacked state of the plurality of pouch-type battery cells 100. In particular, the plurality of pouch-type battery cells 100 may be stacked in a horizontal direction in an erect state, and the cell cover 300 may be configured to stably support the plurality of pouch-type battery cells 100 in an erect state. .

Referring to FIGS. 5 and 7 , the cell cover 300 may be formed in an approximately n-shape. At this time, the front, rear, and bottom of the cell cover 300 may be open.

However, the shape of the cell cover 300 is not limited to an approximately n-shape. The cell cover 300 may be formed in various shapes. For example, the cell cover 300 may be formed in a 'ㅁ' shape, an 'U' shape, or an 'O' shape.

Additionally, the cell cover 300 may be made of a metal material. In particular, the cell cover 300 may be made of a steel material, for example, stainless steel (SUS).

In this case, the stainless steel material has excellent mechanical strength and rigidity and has a higher melting point than the aluminum material, so even if a flame occurs in any battery cell 100, the cell cover 300 is melted by the flame, etc. more effectively. It can be prevented.

That is, not only can damage or breakage of the pouch-type battery cell 100 be prevented more effectively, but also handling of the pouch-type battery cell 100 can be made easier. However, the material of the cell cover 300 is not limited to this.

The cell cover 300 may be at least partially adhered to the pouch-type battery cell 100. Additionally, thermal resin 400 may be interposed between the pouch-type battery cell 100 and the pack case 200 and/or between the cell cover 300 and the pack case 200.

Additionally, the battery pack 10 according to the first embodiment of the present invention may further include a bus bar 700 (see FIG. 4). The bus bar 700 may be connected to the electrode leads of one or more pouch-type battery cells 100.

In particular, the bus bar 700 can connect a plurality of electrode leads to enable serial or parallel connection between the plurality of battery cells 100. For example, electrode leads may be located at the front and rear of each pouch-type battery cell 100. At this time, the bus bar 700 is located at the front and rear of the battery cell 100 and can connect electrode leads.

The bus bar 700 is made of an electrically conductive material such as copper or aluminum and can be in direct contact with the electrode leads.

Additionally, the battery pack 10 according to the present invention may further include a control module configured to control charging and discharging of the pouch-type battery cells 100. Referring to FIG. 1, this control module may include a battery management system (BMS) 500 and a battery cutoff unit 600, together with a battery cell 100 and a cell cover 300, pack It can be stored inside the case 200.

Additionally, the battery pack 10 according to the first embodiment of the present invention may further include an end plate (not shown) coupled to the open portion of the cell cover 300. For example, the cell cover 300 may have open front and rear sides provided with electrode leads. Additionally, an end plate (not shown) may be coupled to the open portion of the cell cover 300. Furthermore, holes or cuts for venting may be formed in the end plate (not shown).

Additionally, when a plurality of battery cells 100 are accommodated in the cell cover 300, a separation structure between the battery cells 100 may be further included.

Figure 8 is a cross-sectional view of a pouch-type battery cell stored inside a battery pack according to a second embodiment of the present invention, and Figure 9 is a process in which the length of the cell cover changes according to expansion and contraction of the pouch-type battery cell of Figure 8. Figure 10 is a diagram schematically showing the pack case configuration of the battery pack according to the second embodiment of the present invention, and Figure 11 is a diagram showing a modified embodiment of Figure 8.

Hereinafter, the operation and effect of the battery pack 10 according to the second embodiment of the present invention will be described with reference to the drawings. However, descriptions that are common to those described in the battery pack 10 according to the first embodiment of the present invention are replaced with the above description. Additionally, the content described in the second embodiment of the present invention can be applied within the scope applicable to the first embodiment described above.

Referring to Figure 10, in the second embodiment of the present invention, a discharge hole 210 may be formed on at least one side of the pack case 200. For example, one or multiple discharge holes 210 may be formed at the bottom of the pack case 200.

Here, the discharge hole 210 may be formed to penetrate the pack case 200 in the inner and outer directions so that gas, etc. in the internal space can be discharged to the outside.

In addition, when a plurality of cell covers 300 are provided, the deformed straight portion 310 formed on the cell cover 300 is configured to change length in the width direction. Here, the communication area with the discharge hole 210 may be varied by changing the length of the cell cover 300 in the width direction.

Figure 9 shows a change in the thickness of the pouch-type battery cell 100 accommodated inside the cell cover 300 in the battery pack 10 according to the second embodiment of the present invention (according to expansion and contraction of the pouch-type battery cell 100). A process in which the length of the cell cover 300 in the width direction changes depending on the thickness change is shown.

Referring to FIG. 9, a cell assembly is shown in which three battery cells 100 are each surrounded by three cell covers 300 and are stacked in the left and right directions.

And, Figures 9(a) to 9(c) show a case in which three situations occur sequentially in this cell assembly.

9(a) to 9(c), the three battery cells 100 are, from left to right, a first cell 100a, a second cell 100b, and a third cell 100c. do. Additionally, the three cell covers 300 are referred to as a first cover 300a, a second cover 300b, and a third cover 300c from left to right.

First, referring to FIG. 9(a), in a general or normal pack state, the widths of the plurality of battery cells 100a, 100b, and 100c and the plurality of cell covers 300a, 300b, and 300c surrounding them are uniform. can be formed.

Then, if thermal runaway occurs in any of the battery cells 100 and is in progress, the internal electrodes may expand. For example, referring to FIG. 9(b), it can be said that thermal runaway has occurred in the second cell 100b, and in this case, the thickness of the second cell 100b may increase.

In addition, due to the increase in the thickness or division of the battery cell 100, the cell cover 300 surrounding the battery cell 100, that is, the second cover 300b, has a width, as shown in FIG. 9(b). The direction length increases. That is, the width of the cell cover 300 (here, the second cover 300b) becomes larger.

Meanwhile, when thermal runaway progresses in any battery cell 100, its thickness or section may be reduced compared to the initial level due to discharge of discharged material. For example, looking at the second cell 100b in FIG. 9(c), it can be seen that the thickness has been reduced compared to the second cell 100b in FIG. 9(b). In this case, it can be said that the thickness of the second cell 100b increased due to thermal runaway, and then decreased in thickness as thermal runaway was completed.

And, in FIG. 9(c), when the thickness of the second cell 100b decreases, the width direction length of the second cover 300b surrounding the second cell 100b decreases. That is, when the thickness or size of the battery cell 100 decreases, the width direction length of the cell cover 300 surrounding the battery cell 100 may decrease.

In addition, comparing Figures 9(a) and 9(b), it can be said that the thickness of the first cell 100a in the normal state of Figure 9(a) has decreased in Figure 9(b), which means , It can be said that this is because the thermal runaway of the first cell 100a progressed and was completed.

In this case, the width of the first cover 300a surrounding the first cell 100a may be reduced. In particular, referring to FIG. 9(b), the width of the first cover 300a may decrease as the width of the second cover 300b increases.

That is, in FIG. 9(b), due to an increase in the width of the second cover 300b, the first cover 300a is pressured from right to left, and the thickness of the first cell 100a decreases through completion of thermal runaway. Since is decreased, space is secured inside the first cover 300a by a decrease in the thickness of the first cell 100a, and accordingly, the width of the first cover 300a can be reduced.

According to this embodiment of the present invention, the length of the cell cover 300 in the width direction can be adaptively changed according to expansion or contraction of the battery cell 100 accommodated therein. Therefore, the shape of the cell cover 300 changes appropriately according to the state of the plurality of battery cells 100, especially thermal runaway situations, so that the overall stacked state of the battery cells 100 and the cell cover 300 is stable without collapsing. can be maintained.

Moreover, if thermal runaway occurs in any battery cell 100, the thermal runaway state may propagate to adjacent cells. According to the above embodiment, the width of the cell cover 300 sequentially changes depending on the propagation situation of thermal runaway. By doing so, there may not be a significant change in the overall shape of the battery pack 10.

Additionally, the cell cover 300 may communicate with the discharge hole 210 of the pack case 200. Accordingly, venting gas, etc. inside the cell cover 300 may be discharged to the external space through the discharge hole 210 of the pack case 200.

Here, by allowing venting gas, etc. to be properly discharged to the outside of the pack case 200, an explosion of the battery pack 10 due to an increase in the internal pressure of the pack case 200 is prevented, while the high temperature venting gas causes the pack case 200 to be properly discharged. (200) As heat accumulates inside, it is possible to more effectively prevent the thermal runaway situation from worsening or spreading.

The cell cover 300 may be configured so that the communication area with the discharge hole 210 of the pack case 200 is variable by changing the length in the width direction.

For example, when the state changes from Figure 9(a) to Figure 9(b), the width of the second cover 300b increases. At this time, the area of the second cover 300b communicating with the discharge hole 210 formed in the pack case 200 may be expanded.

In particular, when the width of the second cover 300b increases, the width of the other cell cover 300, for example, the first cover 300a, may decrease. In this case, the communication area between the first cover (300a) and the discharge hole 210 is reduced, and the second cover (300b) extends to the portion of the discharge hole 210 that was in communication with the first cover (300a), and the communication area is reduced. Area may increase.

For example, as shown in FIG. 9(a), in a normal state, one cell cover 300 has two discharge holes 210 and a communication pipe (first cover 300a, second cover 300b, and third cover). (300c) are all connected to the two discharge holes 210), but in FIG. 9(b), when the width of the second cover 300b increases due to the expansion of the second cell 100b, the second cover 300b has 3 It may be in communication with two discharge holes 210.

That is, in a normal state, the second cover (300b) communicates with the two discharge holes (210), but when the second cell (100b) expands, the second cover (300b) communicates with the three discharge holes (210). , the communication area increases.

According to this embodiment of the present invention, the number of discharge holes 210 in communication with the cell cover 300 changes according to the expansion or contraction of the battery cell 100 accommodated inside the cell cover 300, thereby increasing the overall communication. Since the area varies, this has the effect of enabling appropriate internal pressure control.

In particular, when thermal runaway occurs in the battery cell 100 accommodated inside the cell cover 300, a large amount of venting gas may be discharged through the discharge hole 210. At this time, since the communication area between the cell cover 300 and the discharge hole 210 increases, excessive increase in internal pressure of the cell cover 300 can be suppressed.

In addition, in the case of a battery cell 100 in which thermal runaway has already been completed, the emission of venting gas will not be large, so the communication area between the cell cover 300 and the discharge hole 210 where the battery cell 100 is accommodated is reduced, thereby reducing the situation. Accordingly, an adaptively efficient emission structure can be implemented.

Moreover, in the above implementation configuration of the present invention, the discharge holes 210 can be used in parallel. That is, the cell cover 300 may be configured to use the discharge hole 210 in communication with another cell cover 300 depending on the situation by changing the width.

Here, the discharge hole 210 of the pack case 200 may be formed long along the direction in which the plurality of cell covers 300 are placed. For example, when a plurality of cell covers 300 accommodating battery cells 100 are arranged side by side in the left and right directions, the discharge hole 210 of the pack case 200 is elongated in the left and right directions. can be formed.

Alternatively, referring to FIG. 10 , for example, a plurality of discharge holes 210 may be formed along the arrangement direction of the plurality of cell covers 300. For example, in the above configuration, a plurality of discharge holes 210 of the pack case 200 may be formed in the left and right directions. However, it is not limited to this, and the number, arrangement, and shape of the discharge holes 210 may vary.

Referring to FIG. 8, the cell cover 300 may have a wrinkled upper cover portion. In particular, the cell cover 300 may be formed in a plate shape with two flat sides and a corrugated upper side.

Referring to FIG. 11 as a modified example of FIG. 8, the modified straight portion 310 is formed on the upper side of the cell cover 300, and a triangle portion 319 folded into a triangle shape may be formed. That is, the upper side of the cell cover 300 may be formed in a folded form to have multiple triangular shapes.

As described above, with this implementation configuration, a change in length in the width direction can be more easily implemented in a thermal runaway situation of the internal battery cell 100, etc. Here, the top and two sides of the cell cover 300 may have different thicknesses. In particular, the upper side may be formed to be thinner than the two side sides.

Additionally, the cell cover 300 may be configured to discharge venting gas downward. In particular, the cell cover 300 may be in the form of an n-fin, with the top and left and right sides closed based on the battery cell 100 accommodated therein. At this time, the cell cover 300 may be configured so that the venting gas present inside is discharged downward.

As described above, a discharge hole 210 may be formed in the bottom of the pack case 200. In addition, since the discharge hole 210 of the pack case 200 may communicate with the internal space of the cell cover 300, the venting gas generated from the battery cell 100 inside the cell cover 300 is discharged through the discharge hole 210. ) can be discharged to the outside.

That is, the cell cover 300 and the battery cell 100 are seated on the bottom of the pack case 200, and the venting gas discharged from the battery cell 100 is directed upward and to the side by the cell cover 300. Exhaust is blocked. Additionally, the venting gas can be discharged only downward through the discharge hole 210 of the pack case 200.

In the case of such an implementation configuration, there is an effect of enabling directional venting, that is, venting in a preset direction, through the cell cover 300 and the pack case 200. Moreover, according to the implementation configuration of the present invention, the internal pressure relief effect can be efficiently achieved through rapid and smooth gas discharge along with directional venting by the cell cover 300.

And, referring to FIG. 9, the battery pack 10 according to the present invention may include a thermal barrier 800. The thermal barrier 800 may be configured in the form of a pad made of an insulating material and may be interposed between adjacent cell covers 300. For example, the thermal barrier 800 may be formed to have a thickness of approximately 2.0t, but is not limited thereto.

In addition, the battery pack 10 according to the present invention is formed by stacking a plurality of cell covers 300 and a plurality of battery cells 100, and the outermost layer in the stacking direction of the cell assembly is formed of glass fiber reinforced plastic (GFRP). ) may further include an insulating or prevention pad such as. For example, glass fiber reinforced plastic may be formed to a thickness of 0.35t, but is not limited thereto. Additionally, the battery pack 10 according to the present invention may further include a heating pad.

Meanwhile, one or more battery modules may be stored in the battery pack 10. At this time, the configurations described in the various embodiments described above, particularly the contents of the battery cell 100 and the cell cover 300, may be applied to the battery module.

A battery module according to another aspect of the present invention is a battery module stored in the inner space of the pack case 200, and includes a plurality of pouch-type battery cells 100 and the pouch-type battery cells 100 in the inner space. ) and a module case having an discharge hole 210 formed on at least one side, and at least partially surrounding at least some of the plurality of pouch-type battery cells 100 in the inner space of the module case. and may include a plurality of cell covers 300 configured to change length in the width direction.

An exhaust hole 210 may be formed at the bottom of the module case to discharge venting gas inside the cell cover 300. Additionally, the discharge hole 210 of the module case may be configured to communicate with the storage space of the cell cover 300 stored inside the module case. In this implementation configuration, when venting gas or the like is generated from the battery cell 100 stored inside the cell cover 300, the generated venting gas may be discharged downward rather than upward or forward or backward.

In particular, the cell cover 300 may be configured so that the communication area with the discharge hole 210 of the module case is variable by changing the length in the width direction. Additionally, the discharge hole 210 of the module case may be configured to communicate with the discharge hole 210 of the pack case 200.

In the case of the plurality of pouch-type battery cells 100 and the cell cover 300 included in the battery module, the above-described description of the battery pack 10 may be applied in the same or similar manner, so detailed description is omitted.

Figure 12 is an exploded perspective view of a pouch-type battery cell and a cell cover stored inside a battery pack according to a third embodiment of the present invention, Figure 13 is a combined cross-sectional view of the pouch-type battery cell and cell cover of Figure 12, and Figure 14 is a partial perspective view of the pouch-type battery cell and cell cover of FIG. 12 combined, showing a gas exhaust port, and FIG. 15 is a side cross-sectional view of the pouch-type battery cell of FIG. 12 combined with the cell cover, showing the directional gas exhaust path. The venting part is shown.

Referring to FIGS. 12 and 13 , in the third embodiment of the present invention, the cell cover 300 may include a particle pocket portion 320.

In the third embodiment of the present invention, the side portions 315 and 317 on both sides of the cell cover 300 may be formed to protrude more than the center portion 316, and the deformed straight portion 310 may be formed on both side portions 315 and 317. and the center 316.

Additionally, the particle pocket portion 320 is formed on the deformed straight portion 310 of the cell cover 300 to be spaced apart from the pouch-type battery cell 100. Additionally, the particle pocket unit 320 is configured to collect particles ejected from the pouch-type battery cell 100 when a thermal event occurs.

The particle pocket portion 320 may be configured so that the side portions 315 and 317 on both sides along the width direction of the cell cover 300 protrude more upward than the center portion 316. By this configuration, a preset space above the pouch-type battery cell 100 may be formed inside the cell cover 300.

That is, the particle pocket portion 320 protrudes both side portions 315 and 317 of the cell cover 300, and a preset space is formed inside the protruding portion, and when a thermal event occurs through that space, the battery cell ( 100) It may be configured to collect high-temperature dust, particles, etc. emitted. Here, particles may refer to active materials or molten aluminum particles detached from electrodes inside the battery cell 100.

High-temperature dust, particles, etc. act as ignition sources among the three elements of fire: combustibles, ignition sources, and oxygen. Therefore, when they encounter combustibles and oxygen on the outside of the cell cover 300, ignition occurs and the pack case ( 200) Flames inside can spread rapidly.

Accordingly, it is necessary to prevent high-temperature dust, particles, etc. from escaping to the outside of the cell cover 300.

The cell cover 300 according to this embodiment is provided with a particle pocket portion 320 and can collect high-temperature dust, particles, etc. According to this, even if a thermal event occurs in any pouch-type battery cell 100, it is possible to prevent flames from rapidly spreading to other battery cells 100 or electrical components inside the pack case 200. .

As shown in FIG. 12, for example, the particle pocket portion 320 may be formed on the upper side of the cell cover 300. Due to this shape, the upper side of the cell cover 300 is made of thermal resin 400 and The contact area may increase. In this case, heat conductivity to the outside of the cell cover 300 can be increased, thereby improving cooling efficiency.

That is, referring to FIG. 13, the upper side of the cell cover 300 may be thermally connected to the pack case 200, which has a large heat capacity, through the thermal resin 400. At this time, since the thermal resin 400 fills the concave central area on the upper side of the cell cover 300, the contact area between the cell cover 300 and the thermal resin 400 can be increased. And, this has the effect of improving heat dissipation performance.

Referring to FIG. 15, a mesh member 321 may be formed inside the particle pocket portion 320. The mesh member 321 may be provided in the form of overlapping several porous metal plates to function like a flame arrester.

According to this configuration, the movement of flame, high-temperature dust, particles, etc. within the particle pocket portion 320 can be further restricted, thereby preventing the spread of flame to other battery cells 100.

Referring to FIG. 15, in the battery pack 10 according to the third embodiment of the present invention, a directional venting portion 330 may be formed in the cell cover 300. The directional venting unit 330 is configured to guide the venting gas and discharge it in a preset direction.

When the thermal resin 400 is coupled to the cell cover 300, as shown in FIG. 14, the cell cover 300 has a portion to which the thermal resin 400 is bonded and a portion to which the thermal resin 400 is not bonded. exist.

Additionally, a gas exhaust port 331 may be formed in a portion of the cell cover 300 to which the thermal resin 400 is not coupled. For example, the gas exhaust port 331 may be formed in the lower part of the cell cover 300. Additionally, a moving passage 332 (see FIG. 15) may be formed between the pouch-type battery cell 100 and the cell cover 300.

In this case, the directional venting unit 330 includes the above-described gas exhaust port 331 and the movement passage 332. Referring to the arrow in FIG. 15, the gas generated from the pouch-type battery cell 100 flows through the movement passage ( 332) and can be discharged to the outside through the gas exhaust port 331 toward the lower side of the cell cover 300.

Referring to FIG. 15, when venting gas is generated in the pouch-type battery cell 100, the venting gas may move to the front or rear of the cell cover 300 along the particle pocket portion 320. At this time, particles or flames cannot pass through the mesh member 321 provided in the particle pocket portion 320, and the venting gas passes through the mesh member 321 and includes the movement passage 332 and the gas exhaust port 331. It can be discharged through the directional venting part 330.

In this way, when the directional venting portion 330 is formed on the cell cover 300, when gas is generated from any battery cell 100 included in the battery pack 10, the gas is discharged into other adjacent battery cells 100. ) and may be discharged toward the lower part of the pack case 200 through the directional venting unit 330 without propagating to the other side.

That is, according to this embodiment of the present invention, gas or flame, etc. can be induced to the exposed side of the cell cover 300 and then discharged to the outside of the pack case 200 through the directional venting part 330. By doing this, directional venting can be easily implemented.

Accordingly, the battery pack 10 according to the third embodiment of the present invention has the effect of preventing or suppressing thermal runaway propagation of the pouch-type battery cells 100 when a thermal event occurs.

Figure 16 is a diagram for explaining a vehicle including a battery pack according to each embodiment of the present invention.

The automobile 20 according to an embodiment of the present invention may include one or more battery packs 10 according to each of the above-described embodiments. Here, the vehicle 20 includes various vehicles 20 that are designed to use electricity, such as electric vehicles or hybrid vehicles.

Although the present invention has been described above with limited examples and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the description below will be understood by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalence of the patent claims.

10: Battery pack
100: battery cell 200: pack case
210: discharge hole 300: cell cover
310: Deformed straight part 311, 313, 315, 317: Side part
312, 316: Center 319: Triangle part
320: Particle pocket part 321: Mesh member
330: Directional venting part 331: Gas exhaust port
332: Movement passage 400: Thermal resin
500: Battery management system 600: Battery disconnection unit
700: Busbar 800: Thermal Barrier
20: car

Claims (15)

A plurality of pouch-type battery cells;
a pack case storing the pouch-type battery cells in an internal space; and
A battery pack including a cell cover provided to at least partially surround at least some of the pouch-type battery cells among the plurality of pouch-type battery cells in an internal space of the pack case, and having a deformed straight portion formed on at least one side. According to paragraph 1,
The battery pack, wherein the deformed straight portion is formed in a corrugated structure on the upper side of the cell cover and is configured to unfold when the pouch-type battery cell expands. According to paragraph 2,
A battery pack characterized in that the deformed straight portion has a wave pattern shape in which side portions on both sides protrude toward the top and central portions connected to both side portions are concave toward the bottom. According to paragraph 1,
The cell covers are provided in plural numbers,
A discharge hole is formed on at least one side of the pack case,
The deformed straight portion is configured to change length in the width direction,
A battery pack characterized in that the communication area with the discharge hole is variable by changing the length of the cell cover in the width direction. According to paragraph 4,
A battery pack, characterized in that the discharge holes of the pack case are formed long or formed in multiple numbers along the arrangement direction of the plurality of cell covers. According to paragraph 4,
The battery pack, wherein the deformed straight portion is formed on an upper side of the cell cover, and a triangle portion folded into a triangle shape is formed. According to paragraph 1,
The cell cover is configured to be spaced apart from the pouch-type battery cell and includes a particle pocket portion configured to collect particles ejected from the pouch-type battery cell when a thermal event occurs. In clause 7,
The particle pocket portion is a battery pack characterized in that both side portions along the width direction of the cell cover are configured to protrude more toward the top than the center portion. In clause 7,
A battery pack, characterized in that a mesh member is formed inside the particle pocket portion. In clause 7,
A battery pack characterized in that the cell cover is formed with a directional venting portion that guides venting gas and discharges it in a preset direction. According to clause 10,
Including thermal resin coupled to the cell cover,
The cell cover has a portion to which the thermal resin is bonded and a portion to which the thermal resin is not bonded,
The directional venting part,
a gas exhaust port formed in a portion of the cell cover to which the thermal region is not coupled; and
A battery pack comprising a moving passage formed between the pouch-type battery cell and the cell cover. According to paragraph 1,
The cell cover is a battery pack characterized in that it is configured to partially surround the pouch-type battery cell so that at least one side of the wrapped pouch-type battery cell is exposed to the outside. According to paragraph 1,
The cell cover is a battery pack characterized in that at least one side of the wrapped pouch-type battery cell is exposed toward the bottom of the battery pack. According to paragraph 1,
A battery pack, wherein the cell cover is directly mounted on the pack case. A vehicle comprising a battery pack according to any one of claims 1 to 14.

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