KR102322910B1 - Battery case, battery pack including the same, and vehicle including the same - Google Patents

Abstract

In the battery case according to the present invention, the battery case accommodates a cell assembly in which a plurality of battery cells are stacked, a lower case with an open upper portion, an upper case covering the upper portion of the open lower case, and the lower case and the The upper case is coupled to each other and includes a sealing unit sealing the lower case and the accommodation space formed inside the upper case.

Description

Battery case, battery pack including the same, and vehicle including the same}

The present invention relates to a battery case, a battery pack including the same, and a vehicle, and more particularly, the internal gas discharged from the space between the upper case and the lower case to the outside passes, and the external gas introduced into the space from the outside is It relates to a blocking battery case, a battery pack including the same, and a vehicle.

Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries, so charging and discharging are free, The self-discharge rate is very low and the energy density is high, attracting attention.

Such a lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are applied, respectively, are disposed with a separator therebetween, and a packaging material for sealingly housing the electrode assembly together with an electrolyte.

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

Recently, secondary batteries have been widely used not only in small devices such as portable electronic devices, but also in medium and large devices such as automobiles and power storage devices. When used in such a medium-large device, a large number of secondary batteries are electrically connected to increase capacity and output. In particular, a pouch-type secondary battery is often used in such a medium or large-sized device due to the advantage of easy stacking. In addition, such a plurality of secondary batteries may be accommodated in a pack case to constitute one battery pack.

Various characteristics are required for such a battery pack, and among them, a representative characteristic is safety. Moreover, the safety of a battery pack mounted on a vehicle is very important because it is directly related to the life of an occupant.

In particular, one of the important issues in relation to the safety of the battery pack is the direct exposure to flame. In the case of a battery pack, it is a top priority to prevent a fire from occurring inside, but in some cases, a fire may occur inside the battery pack. At this time, when oxygen is continuously supplied to the inside of the battery pack from the outside, a small-scale flame generated from the battery pack develops into a large-scale fire and high-temperature gas is generated along with the flame, so that not only the internal parts of the battery pack but also the battery pack It may break or damage other components in the vicinity. In particular, when a fire occurs in a battery pack mounted on a vehicle, the generated fire may become a very dangerous factor for occupants. Moreover, when the battery pack is installed in a hybrid vehicle or collides with another vehicle, exposure to flames or high-temperature gas in the fuel storage tank may cause an explosion of fuel, which may lead to a serious accident.

The present invention seals the accommodating space formed inside the upper case and the lower case for accommodating the cell assembly, and the inner gas discharged to the outside from the spaced space formed by the upper sidewall of the upper case and the lower sidewall of the lower case being spaced apart. An object of the present invention is to provide a battery case capable of passing or blocking an external gas flowing into the separation space from the outside, a battery pack including the same, and a vehicle.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

The battery case according to the present invention for solving the above technical problem accommodates a cell assembly in which a plurality of battery cells are stacked therein, a lower case with an open upper portion, an upper case covering an upper portion of the open lower case, and the The lower case and the upper case are coupled to each other to include a sealing part sealing the accommodation space formed in the lower case and the upper case.

Preferably, the lower case may include a lower plate that covers a lower surface of the cell assembly and a lower sidewall that extends upwardly from an edge of the lower plate to cover a side surface of the cell assembly.

Preferably, the upper case may include an upper plate that covers an upper surface of the cell assembly and an upper portion of the open lower case, and an upper sidewall extending downward from an edge of the upper plate and surrounding the outer periphery of the lower sidewall. .

Preferably, the sealing part is formed in a band shape, and the upper part is in close contact with the upper sidewall, and the lower part is in close contact with the lower sidewall to seal the accommodation space from the outside.

Preferably, the sealing part may have an adhesive layer formed on the surfaces facing the upper case and the lower case so that the upper part is adhered to the upper sidewall, and the lower part is adhered to the lower sidewall.

Preferably, the sealing part may pass an internal gas discharged to the outside in a space formed by separating the upper sidewall and the lower sidewall to be spaced apart, or may block an external gas flowing into the spaced space from the outside.

Preferably, the valve portion is cut from the surface facing the upper case and the lower case to a preset cut-out section, and the cut-out line is formed to extend from the cut-out portion and the cut-out portion formed in a closed curve shape toward the inside of the perforation line, The side surfaces may be provided with a plurality of wings formed to fill the inner side of the perforated line in contact with each other.

Preferably, the plurality of wing portions may be spaced apart from each other by being applied to the pressure of the internal gas and spread outward.

Preferably, the plurality of wing portions are supported on the other cut-out side of the cut-out portion on the side extending from the cut-out portion to block the external gas flowing into the separation space from the outside.

The battery pack according to the present invention may include the battery case.

The vehicle according to the present invention may include the battery pack.

According to the present invention, the sealing part seals the accommodation space formed inside the upper case and the lower case for accommodating the cell assembly, and the inner side discharged to the outside from the spaced space formed by the upper sidewall of the upper case and the lower sidewall of the lower case being spaced apart By passing the gas or blocking the external gas flowing into the separation space from the outside, it is possible to prevent a small flame generated inside the battery pack from developing into a large flame.

1 is a perspective view of a battery case according to an embodiment of the present invention.
2 is an exploded perspective view of a battery case and a battery according to an embodiment of the present invention.
3 is a side view of a battery case according to an embodiment of the present invention.
FIG. 4 is a view showing a part of a cross section taken along line A-A' of FIG. 1 .
FIG. 5 is an enlarged view of the side surface of the sealing part shown in FIG. 4 .
FIG. 6 is an enlarged view showing the surface of the sealing part shown in FIG. 4 .
7 is an enlarged view illustrating a side surface of a sealing part through which an internal gas passes.
8 is an enlarged view showing the surface of the sealing part through which the internal gas passes.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

1 is a perspective view of a battery case according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a battery case and a battery according to an embodiment of the present invention, and FIG. 3 is a battery case according to an embodiment of the present invention. It is a side view.

1 to 3 , the battery case according to an embodiment of the present invention may include a lower case 100 , an upper case 200 , and a sealing part.

The lower case 100 may accommodate the cell assembly 10 in which a plurality of battery cells 11 are stacked, and an upper portion thereof may be opened. More specifically, the lower case 100 may cover the lower surface and all four sides of the cell assembly 10 .

To this end, the lower case 100 may include a lower plate 110 and a lower side wall 120 .

The lower plate 110 of the lower case 100 may cover the lower surface of the cell assembly 10 . In addition, the lower sidewall 120 of the lower case 100 may extend upwardly from the edge of the lower plate 110 to cover the side surface of the cell assembly 10 .

Meanwhile, the lower sidewall 120 of the lower case 100 may have a lower coupling hole 121 formed therethrough.

The lower coupling hole 121 is formed to pass through the upper portion of the lower sidewall 120 and is formed so as to correspond to the formed position with the upper coupling hole 221 formed through the upper sidewall 220 of the upper case 200 to be described later. can

In other words, the lower coupling hole 121 and the upper coupling hole 221 may be formed at positions corresponding to each other so that the through holes coincide when the lower case 100 and the upper case 200 are coupled.

At this time, the lower case 100 and the upper case 200 may be coupled to each other by screwing the bolt B into the lower coupling hole 121 and the upper coupling hole 221 .

Meanwhile, the cell assembly 10 accommodated in the battery case according to the present invention may be formed in a structure in which a plurality of battery cells 11 are stacked. The types of the plurality of battery cells 11 are not particularly limited, and various secondary batteries may be employed in the present invention. For example, the battery cell 11 may include a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydride battery, a nickel zinc battery, and the like. In particular, the battery cell 11 may be a lithium secondary battery.

The upper case 200 may cover an upper portion of the open lower case 100 .

More specifically, the upper case 200 may be coupled to the lower case 100 so as to cover the upper portion of the lower case 100 in which the cell assembly 10 is accommodated.

To this end, the upper case 200 may include a top plate 210 and an upper sidewall 220 .

The upper plate 210 of the upper case 200 may cover the open upper portion of the lower case 100 together with the upper surface of the cell assembly 10 . To this end, the upper plate 210 of the upper case 200 may be formed to be larger than the area of the lower plate 110 of the lower case 100 .

The upper sidewall 220 of the upper case 200 may extend downward from the edge of the upper plate 210 to surround the outer periphery of the lower sidewall 120 .

FIG. 4 is a view showing a part of a cross section taken along line A-A' of FIG. 1 .

Referring to FIG. 4 , the upper sidewall 220 of the upper case 200 may be spaced apart from the lower sidewall 120 of the lower case 100 by T to surround the outer periphery of the lower sidewall 120 .

Meanwhile, the upper sidewall 220 of the upper case 200 may have an upper coupling hole 221 formed therethrough.

The upper coupling hole 221 may be formed to penetrate the center of the upper sidewall 220 , and as described above, may be formed to correspond to the formed position with the lower coupling hole 121 formed through the lower sidewall 120 .

In addition, the upper case 200 and the lower case 100 may be coupled to each other by screwing the bolt B into the upper coupling hole 221 and the lower coupling hole 121 .

At this time, as shown in FIG. 4 , the upper side wall 220 and the lower side wall 120 are spaced apart from each other even if the bolt B is screwed into the upper coupling hole 221 and the lower coupling hole 121 . can

Hereinafter, a space formed by separating the upper sidewall 220 and the lower sidewall 120 is referred to as a spaced space T. Referring to FIG.

In the battery case according to the present invention, in order to block the phenomenon that the internal gas (IS) is discharged from the battery case to the outside through the separation space (T) and the external gas (OS) is introduced into the battery case from the outside, the sealing part is It may be coupled to the lower case 100 and the upper case 200 .

More specifically, the sealing part may seal the accommodation space formed inside the lower case 100 and the upper case 200 by coupling the lower case 100 and the upper case 200 .

In this case, the sealing part may be a band-shaped insulating tape (Imide tape).

As shown in FIG. 1 , the sealing portion is attached to the upper sidewall 220 of the upper case 200 , and the lower portion is attached to the lower sidewall 120 of the lower case 100 , thereby sealing the accommodation space. can

In other words, an adhesive layer is formed on the surface facing the upper case 200 and the lower case 100 among the wide surfaces of the sealing part, the upper part of the adhesive layer is attached to the upper side wall 220, and the lower part of the adhesive layer is the lower side wall 120 ), it is possible to seal the accommodation space formed inside the upper case 200 and the lower case 100 .

FIG. 5 is an enlarged view showing the side surface of the sealing part shown in FIG. 4 , and FIG. 6 is an enlarged view showing the surface of the sealing part shown in FIG. 4 .

5 and 6 , the sealing part may include a valve part 310 .

A plurality of valve parts 310 are formed on the surface of the sealing part, and the internal gas (IS) discharged to the outside from the separation space (T) passes or the external gas (OS) flows into the separation space (T) from the outside. can be blocked.

Here, the internal gas IS may mean a gas generated due to overcharging and aging of the battery cell 11 , and the external gas OS may mean an atmosphere containing oxygen flowing outside the battery case. have.

As shown in FIG. 5 , the valve portion 310 may include a cutout portion 312 and a plurality of wing portions 311 .

The cutout 312 may be formed by cutting from the surface of the sealing part facing the upper case 200 and the lower case 100 to a preset cutout section.

That is, as shown in FIG. 4 , the cutout 312 is a cutout section cut from the surface facing the upper case 200 and the lower case 100 from the surface of the sealing part to a preset cutout section, and a preset cutout section From the upper case 200 to the opposite surface of the lower case 100 may be composed of a non-cut portion not cut.

In other words, the cut-out portion 312 may be formed by contacting the cut-out portion and the non-cut portion, which are not cut, when looking at the cross-section.

As shown in FIG. 5 , the cut-out 312 may have a cut-off line on the surface facing the upper case 200 and the lower case 100 in a closed curve shape.

That is, the cut-out portion 312 may be cut in a circular shape, a square shape, etc. to form a closed curve, and the cut-out depth may be cut to correspond to a preset cut-out section.

The plurality of wings 311 may be formed to extend from the above-described cut-out 312 toward the inside of the cut-out line of the closed curve shape. More specifically, each of the plurality of wing portions 311 is formed to have one side extending from the non-cut portion among the above-described cut-out portions 312 , and the extending direction may be toward the inside of the cut-out line of the cut-out portion 312 .

Accordingly, the plurality of wing portions 311 may be formed to extend from the cut-out portion 312 toward the inside of the perforated line, and thus the extended ends may be formed to face each other.

In this case, the plurality of wing portions 311 may be formed such that side surfaces of the plurality of wing portions 311 excluding the side extending from the cutout 312 are in contact with each other to fill the inside of the perforated line of the closed curve shape.

More specifically, one side of the plurality of wings 311 may extend from the non-cut section of the cutout 312 as described above. Accordingly, each of the plurality of wing parts 311 may have a side that does not extend from the cutout 312 among the side surfaces, and side surfaces other than the side extending from the cutout 312 may be formed to contact each other.

Meanwhile, the valve part 310 may further include a support part 313 surrounding the cut-out part 312 .

The support portion 313 may be located outside the perforated line formed by the cutout 312 , and may be formed by the cutout 312 .

That is, when the cut-out 312 is cut, a side facing the perforated line is formed among the side surfaces of the plurality of wing parts 311 on the inside of the perforated line, and one side of the support 313 may be formed on the outside of the perforated line. have.

As shown in FIG. 4 , the support part 313 supports the side facing the perforation line among the side surfaces of the plurality of wing parts 311 , so that the plurality of wing parts 311 are opened toward the separation space (T). can prevent

Accordingly, when the external gas (OS) flowing from the outside of the battery case moves toward the plurality of wing parts 311 , the support part 313 supports the side of the plurality of wing parts 311 toward the perforation line. By preventing the plurality of wing portions 311 from being opened toward the separation space T, it is possible to block the external gas OS flowing into the separation space T.

In other words, the plurality of wing parts 311 are supported on the side surface of the support part 313, which is the other side cut out of the cut-out part 312, in which the side extending from the cut-out part 312 is provided to the spaced space T from the outside. It is possible to block the inflow of external gas (OS).

According to this configuration of the present invention, by blocking the external gas (OS) flowing into the accommodating space inside the battery case and the separation space T between the upper case 200 and the lower case 100, the inside of the battery pack Even if a small flame occurs, it is possible to prevent the development of a large flame by cutting off the oxygen supply.

FIG. 7 is an enlarged view showing the side surface of the sealing part that passes the internal gas IS, and FIG. 8 is an enlarged view showing the surface of the sealing part that passes the internal gas IS.

Referring to FIGS. 7 and 8 , the plurality of valve parts 310 included in the sealing part may pass through the internal gas (IS) generated in the battery cell 11 to the outside when the internal gas (IS) flows in the separation space (T). have.

More specifically, when the plurality of wing parts 311 provided in the valve part 310 generate the internal gas IS from the battery cell 11 and flow to the separation space T, the increased internal gas IS ) can be applied to the internal pressure of the battery case and open toward the outside.

As described above, when the external gas OS flows toward the separation space T, the plurality of wing portions 311 are supported by the support portion 313 and do not spread toward the separation space T, but a plurality The wing portion 311 of the cut-out portion 312 may be opened toward the outside, as the cut-out portion is opened.

Due to this, the side surfaces of the plurality of wings 311 except for the side extending from the cut-out 312 are in contact with each other, and the contacted side surfaces are spaced apart from each other by spreading outward, and from the center of the above-mentioned perforation line The separation space T may communicate with the outside.

Accordingly, the internal gas IS flowing through the separation space T may be discharged to the outside through the space in which the plurality of wing parts 311 are opened.

According to this configuration of the present invention, the external gas (OS) flowing from the outside of the battery case blocks the inflow into the separation space (T), that is, the inside of the battery case, and increases the internal gas (OS) in the separation space (T). IS) can be discharged by passing it to the outside.

Through this, the battery case according to the present invention discharges the internal gas (IS) flowing in the accommodating space inside and the space T between the upper case 200 and the lower case 100 to the outside, thereby causing swelling due to swelling. It can prevent the explosion of the battery pack.

For those of ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible within the scope of the present invention without departing from the technical spirit of the present invention. is not limited by

100: lower case 200: upper case
300: seal

Claims (10)

a lower case accommodating a cell assembly in which a plurality of battery cells are stacked therein, and having an open top;
an upper case covering the upper part of the open lower case; and
and a sealing part in which the lower case and the upper case are coupled to seal the accommodation space formed inside the lower case and the upper case,
The lower case is
a lower plate covering the lower surface of the cell assembly; and
and a lower sidewall extending upwardly from an edge of the lower plate to cover a side surface of the cell assembly,
The upper case is
an upper plate covering an upper surface of the cell assembly and an upper portion of the open lower case; and
and an upper sidewall extending downward from the edge of the upper plate and surrounding the outer periphery of the lower sidewall,
The upper sidewall is positioned to be spaced apart from the lower sidewall so as to cover the lower sidewall and a spaced space is formed between the upper sidewall and the lower sidewall,
The upper sidewall and the lower sidewall are fastened by bolts,
The sealing portion is attached to the upper sidewall and the lower sidewall to cover the opening formed between the lower end and the lower sidewall of the upper sidewall,
The sealing part includes a valve part that passes the internal gas discharged to the outside from the separation space but blocks the external gas flowing into the separation space from the outside,
The sealing part is a strip-shaped insulating tape,
The valve portion is provided at a position corresponding to the separation space formed between the upper sidewall and the lower sidewall,
The valve portion includes a wing portion formed by cutting off a portion of the insulating tape,
The valve portion may include the insulating tape on the inner surface of the insulating tape so that the wing portion is relatively easily bent in a direction opposite to the direction toward the separation space and not relatively easily bent in a direction toward the separation space. and a cutout formed to a depth shallower than the thickness of the tape,
The valve part is bent in a direction opposite to the direction in which the wing part faces the separation space, thereby discharging gas to the outside when the gas pressure in the accommodating space increases, and preventing outside air from flowing into the separation space.
delete According to claim 1,
the sealing part
A battery case that is formed in a band shape and has an upper portion in close contact with the upper sidewall and a lower portion in close contact with the lower sidewall to seal the accommodating space from the outside.
According to claim 1,
the sealing part
An adhesive layer is formed on the surfaces facing the upper case and the lower case so that the upper part is adhered to the upper sidewall, and the lower part is adhered to the lower sidewall.
delete According to claim 1,
The valve part
The upper case and the lower case are cut from the surface facing the lower case to a preset cut-out section, and the cut-out line is formed in a closed curve shape, and
A plurality of wing portions extending from the cut-out portion toward the inside of the perforation line and having side surfaces in contact with each other to fill the inner side of the perforation line
battery case.
7. The method of claim 6,
The plurality of wings
A battery case that is spaced apart from each other by being applied to the pressure of the internal gas and spreading outward.
7. The method of claim 6,
The plurality of wings
A battery case in which a side extending from the cut-out is supported on the other cut-out side of the cut-out to block external gas flowing into the separation space from the outside.
The battery case according to any one of claims 1, 3, 4, and 6 to 8
Included battery pack.
The battery pack according to claim 9
including cars.

Images