KR20240109802A - Battery device - Google Patents

Abstract

A battery device according to an embodiment of the present invention includes a cell stack in which a plurality of battery cells are stacked, a bus bar assembly coupled to the cell stack and electrically connecting the plurality of battery cells to each other, the cell stack and the It may include a housing that accommodates the bus bar assembly therein, and a flame retardant member disposed between the bus bar assembly and the housing to block the spread of flame.

Description

Battery device {BATTERY DEVICE}

The present invention relates to a battery device with high stability.

Unlike primary batteries, secondary batteries can be charged and discharged, so they can be applied to various fields such as digital cameras, mobile phones, laptops, and hybrid cars. Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, and lithium secondary batteries.

Among these secondary batteries, much research is in progress on lithium secondary batteries with high energy density and discharge voltage. Recently, lithium secondary batteries have been manufactured as flexible pouch-type battery cells, connecting multiple units to form modules. It is used in pack form.

However, when multiple battery modules are placed adjacently, such as in a battery pack, if one battery module ignites, flames may spread to other adjacent battery modules, which may cause secondary ignition or explosion. Therefore, there is a need for a battery device that can suppress the propagation of the above-described flames.

The purpose of the present invention is to provide a battery device that can suppress the spread of flame or thermal runaway.

A battery device according to an embodiment of the present invention includes a cell stack in which a plurality of battery cells are stacked, a bus bar assembly coupled to the cell stack and electrically connecting the plurality of battery cells to each other, the cell stack and the It may include a housing that accommodates the bus bar assembly therein, and a flame retardant member disposed between the bus bar assembly and the housing to block the spread of flame.

In this embodiment, a connection terminal electrically connected to the outside is disposed on the first side of the housing, and the flame-retardant member may be disposed between the bus bar assembly and the first side of the housing.

In this embodiment, it may further include a bus bar cover disposed between the bus bar assembly and the housing, and the flame retardant member may be disposed between the bus bar cover and the housing.

In this embodiment, the flame retardant member may be a fire-resistant adhesive that is injected in liquid form between the bus bar cover and the housing and then hardened.

In this embodiment, the bus bar cover has an edge in surface contact with the inner surface of the housing, and may further include a sealing member interposed between the contact surface of the bus bar cover and the housing.

In this embodiment, the sealing member may include a gasket or O-ring.

In this embodiment, the flame retardant member may be formed of a material with an ignition point of 700°C or higher.

In this embodiment, the housing may have at least one venting hole formed on a second surface disposed on the top of the cell stack.

In this embodiment, it further includes a blocking member coupled to the second surface of the housing, and the blocking member may be coupled to the second surface of the housing in a form that blocks the at least one venting hole.

In this embodiment, the blocking member includes any one of a fire-resistant foam pad, metal foam, and ceramic wool, and can pass gas and block flame.

In this embodiment, the blocking member is formed of a mica sheet, and a fractured portion that fractures at a lower pressure than other portions may be formed in a region of the blocking member corresponding to the venting hole.

In the battery device according to an embodiment of the present invention, a flame-retardant member is disposed between the cell stack and the housing where the connection terminal is disposed. Therefore, even if one of the battery cells explodes and explosion by-products are discharged, the flame-retardant member can prevent the explosion by-products from spreading toward the connection terminal of the battery device.

1 is a perspective view schematically showing a battery module according to an embodiment of the present invention.
Figure 2 is an exploded perspective view of the battery module shown in Figure 1.
Figure 3 is an enlarged perspective view of the battery cell of Figure 2.
Figure 4 is a partial cross-sectional view taken along line II' in Figure 1;
FIG. 5 is an exploded perspective view of the second housing shown in FIG. 2.
FIG. 6 is a cross-sectional view illustrating another embodiment of the blocking member shown in FIG. 5.
Figures 7 and 8 are partially exploded perspective views showing an enlarged view of the bus bar assembly and bus bar cover shown in Figure 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the accompanying drawings, some components are exaggerated, omitted, or schematically shown, and the size of each component does not entirely reflect the actual size.

Figure 1 is a perspective view schematically showing a battery module according to an embodiment of the present invention, and Figure 2 is an exploded perspective view of the battery module shown in Figure 1. Additionally, FIG. 3 is an enlarged perspective view of the battery cell of FIG. 2, and FIG. 4 is a partial cross-sectional view taken along line II' of FIG. 1.

1 to 4, the battery device 100 of this embodiment includes a cell stack 1, a housing 30, a bus bar assembly 70, a bus bar cover 90, and a flame retardant member 85. may include.

The cell stack 1 can be formed by stacking a plurality of battery cells 10. In this embodiment, the battery cells 10 are stacked in the thickness direction. Each of the battery cells 10 may be a pouched type secondary battery, and may have a structure in which the electrode leads 15 are arranged to face opposite directions.

Referring to FIG. 3, the battery cell 10 may be configured with an electrode assembly (not shown) accommodated in the cell case 11.

The electrode assembly includes a plurality of electrode plates and electrode tabs and may be placed in the cell case 11 together with the electrolyte solution. Here, the electrode plate is composed of a positive electrode plate and a negative electrode plate, and the electrode assembly may be formed by stacking the positive electrode plate and the negative electrode plate so that the wide surfaces face each other with a separator in between.

The positive and negative electrode plates may each be provided with an electrode tab connected to the electrode lead 15, and electrode plates of the same polarity may be connected to the same electrode lead 15.

The cell case 11 forms the outer shape of the battery cell 10 and may provide an internal space where the electrode assembly and electrolyte are accommodated. At this time, a portion of the electrode lead 15 connected to the electrode assembly may be exposed to the outside of the cell case 11.

The cell case 11 may be divided into a sealing portion 202 and a receiving portion 204.

The receiving portion 204 may provide a sealed internal space. The electrode assembly and electrolyte solution described above may be accommodated in the internal space of the receiving portion 204.

The sealing portion 202 is formed along the circumference of the receiving portion 204 to seal the receiving portion 204. Accordingly, the sealing portion 202 may be formed in a flange shape extending outward from the receiving portion 204.

The sealing portion 202 may be defined as an area where the cell cases 11 are arranged to overlap and are bonded to each other. The sealing portions 202 may be bonded to each other using a heat fusion method, but the configuration of the present invention is not limited thereto.

Additionally, in this embodiment, the sealing part 202 may be divided into a first sealing part 2021 in which the electrode lead 15 is disposed, and a second sealing part 2022 in which the electrode lead 15 is not disposed.

In this embodiment, the cell case 11 can be formed by forming a single sheet of exterior material. More specifically, the cell case 11 can be completed by forming one or two grooves in one exterior material and then folding the exterior material so that the grooves form one space (i.e., a receiving portion).

In this embodiment, the receiving portion 204 may be formed in a square shape. When forming the cell case 11 by folding a single sheet of exterior material, there is no need to form a sealing portion 202 on the side where the exterior material is folded (lower surface in FIG. 2). Accordingly, in this embodiment, the sealing portion 202 may be provided on only three of the four sides forming the exterior of the receiving portion 204.

However, the present invention is not limited to this, and when the cell case 11 is formed by bonding two exterior materials together, the sealing portion 202 may be provided on all four sides.

Additionally, the sealing portion 202 of this embodiment may be fixed by the adhesive member 17 in a folded state at least once along the bending lines C1 and C2. Accordingly, the sealing reliability of the sealing part 202 can be increased and the volume occupied by the sealing part 202 can be minimized.

The battery cell 10 configured in this way is a secondary battery capable of repeated charging and discharging, and may be a lithium (Li) battery or a nickel-hydrogen (Ni-MH) battery.

The housing 30 defines the external shape of the battery device 100 and is disposed outside the plurality of battery cells 10 to protect the battery cells 10 from the external environment. At the same time, the housing 30 of this embodiment can also be used as a heat dissipation member of the battery device 100.

For easy manufacturing of the battery device 100, the housing 30 may be divided into multiple pieces. For example, the housing 30 of this embodiment includes a first housing 50 disposed on one side of the cell stack 1, a second housing 40 disposed on the other side of the battery cells 10, and a battery. It may include a third housing 60 disposed on a side where the electrode leads 15 of the cells 10 are disposed.

The first housing 50 includes a lower plate 52 disposed below the cell stack 1 to support the lower surface of the cell stack 1, and the battery cells 10 in the cell stack 1. The receiving portion 204 may include a side plate 58 supporting the exposed side. However, if necessary, it is also possible to configure the side plate 58 and the lower plate 52 as independent components.

The side plate 58 extends from both sides of the lower plate 52 and can support the battery cells 10 arranged on both sides of the cell stack 1 stacked in the left and right directions.

In order to firmly support the battery cell 10, the side plate 58 may be configured to press the receiving portion 204 of the battery cell 10 at a certain pressure.

The second housing 40 may be disposed on top of the cell stack 1 and coupled to the first housing 50 . The second housing 40 is provided in the form of a flat plate and can be fastened to the top of the side plate 58 of the first housing 50. Accordingly, when the second housing 40 is fastened to the first housing 50, the second housing 40 and the first housing 50 may have the shape of a tubular member with an empty interior. Hereinafter, for convenience of explanation, the second housing 40, which is the part of the housing 30 disposed on the upper part of the cell stack 1, will be referred to as the second surface of the housing 30.

The first housing 50 and the second housing 40 configured in this way may be made of a material with high thermal conductivity, such as metal. For example, the first housing 50 and the second housing 40 may be made of aluminum. However, it is not limited to this, and various materials can be used as long as they have thermal conductivity similar to metal, even if they are not metal.

The first housing 50 and the second housing 40 may be joined by welding or the like. However, it is not limited to this, and various modifications are possible, such as coupling in a sliding manner or coupling using fixing members such as bolts or screws.

Meanwhile, in this embodiment, the first housing 50 and the second housing 40 are separately provided and coupled to each other, but the configuration of the present invention is not limited thereto, and the first housing 50 and the second housing 40 are used as necessary. It is also possible to manufacture (40) integrally.

Meanwhile, the housing 30 of this embodiment may have a plurality of venting holes 45 provided on the second side of the housing 40, which is the second side.

FIG. 5 is an enlarged exploded perspective view of the second housing shown in FIG. 2.

Referring to FIG. 5 , the venting hole 45 may be formed as a hole penetrating the second housing 40, and a plurality of venting holes 45 may be spaced apart from each other.

When gas is discharged from the battery cell 10, the venting hole 45 may be used as a path through which the gas is discharged to the outside of the battery device 100. Accordingly, the venting holes 45 may be distributed and disposed in areas corresponding to the cell stack 1. Additionally, in order to prevent unnecessary foreign substances from entering the battery device 100 through the venting hole 45, a blocking member 48 may be disposed on the inner surface of the second housing 40. The blocking member 48 may be coupled to the second housing 40 in the form of blocking the venting holes 45, and may be formed in the form of a single sheet and attached to the inner surface of the second housing 40. However, it is not limited to this. For example, the blocking member 48 may be attached to the outer surface of the second housing 40 or may be inserted into each venting hole 45.

When gas is generated inside the battery device 100, the gas may pass through the blocking member 48 and the venting hole 45 and be discharged to the outside of the battery device 100. To this end, the blocking member 48 may be formed of a material that allows gas to pass through, or may be configured to break at a certain pressure or higher.

The blocking member 48 of this embodiment may be formed of a refractory sheet containing a refractory material such as mica. In this case, the blocking member 48 may be configured to have a fractured portion 49 that is relatively vulnerable to pressure so that when the internal pressure of the battery device 100 increases, the fractured portion 49 is preferentially fractured. The fracture portion 49 may be formed in an area corresponding to each venting hole 45, and the thickness of the blocking member 48 may be formed to be relatively thin or the mica sheet may be partially cut to have a lower thickness compared to other portions. The portion may be configured to fracture or open under pressure. However, the configuration of the present invention is not limited to this.

Additionally, the blocking member 48 of this embodiment may include any one of a fire-resistant foam pad (e.g., urethane foam), metal foam, or ceramic wool, and may allow gas to pass through and flame to block. It can be formed from a material. In this case, when the battery cell 10 in the battery device 100 explodes, only gas among the explosion by-products passes through the blocking member 48 and is discharged to the outside of the battery device 100, and flames or foreign substances, etc. are discharged from the blocking member ( 48), the flow may be blocked. Accordingly, since flames or foreign substances are not discharged to the outside of the battery device 100, it is possible to fundamentally prevent such flames or foreign substances from flowing into other battery cells 10 through the other vent holes 45.

FIG. 6 is a cross-sectional view illustrating another embodiment of the blocking member shown in FIG. 5, and is a partial cross-sectional view taken along line II′ of FIG. 1.

Referring to FIG. 6, the blocking member 48a of the present embodiment may be made of a material that allows gas (G) to pass through and flame to block, such as a fireproof foam pad (e.g., urethane foam) and ceramic wool. . In this case, when the battery cell 10 in the battery device 100 explodes, only gas (G) among the explosion by-products passes through the blocking member 48 and is discharged to the outside of the battery device 100, and flames or foreign substances, etc. The flow may be blocked by the blocking member 48. Accordingly, since flames or foreign substances are not discharged to the outside of the battery device 100, it is possible to fundamentally prevent such flames or foreign substances from flowing into other battery cells 10 through the other vent holes 45.

The third housings 60 may be respectively coupled to both sides where the electrode leads 15 of the battery cells 10 are disposed.

As shown in FIGS. 1 and 2, the third housings 60 are coupled to the first housing 50 and the second housing 40 and are coupled to the first housing 50 and the second housing 40. The outer surface of the battery device 100 may be configured.

In this embodiment, the third housings 60 are made of metal. However, it is not limited to this, and if necessary, it is possible to form part or all of it from an insulating material such as resin.

A connection terminal 72 may be disposed to protrude to the outside of at least one of the third housings 60 . Hereinafter, the surface of the third housings 60 on which the connection terminal 72 is disposed will be referred to as the first surface of the housing 30. Accordingly, the third housing 60 forming the first surface of the housing 30 may be provided with a terminal hole 62 for exposing the connection terminal 72 to the outside.

In this embodiment, the case where both connection terminals 72 are disposed in one third housing 60 is given as an example, but this is not limited, and connection terminals may be connected to each of the two third housings 60 as necessary. (72) may also be placed.

The third housings 60 may be coupled to the first housing 50 and the second housing 40 using fastening members such as screws or bolts, or by welding or adhesive methods. However, the configuration of the present invention is not limited to this.

A bus bar assembly 70, a bus bar cover 90, and a flame retardant member 85 may be interposed between the third housing 60 and the cell stack 1.

The bus bar assembly 70 may be disposed on the side where the electrode leads 15 of the battery cells 10 are disposed and coupled to the cell stack 1, and includes at least one bus bar 80 and an insulating frame ( 71) may be included.

Figures 7 and 8 are partially exploded perspective views showing an enlarged view of the bus bar assembly and bus bar cover shown in Figure 2. Figure 7 shows the bus bar assembly and bus bar cover shown on the right side of Figure 2. Figure 8 shows the bus bar assembly and bus bar cover shown on the left.

Referring to FIGS. 7 and 8 together, the insulating frame 71 is formed of an insulating material, and at least a portion of the bus bar 80 is embedded within the insulating frame 71 or fixed to one surface of the insulating frame 71. can be combined

The insulating frame 71 may be provided with a plurality of through holes 73 into which the electrode leads 15 are inserted.

The bus bar assembly 70 may be provided with a connection terminal 72 for electrically connecting the battery cells 10 to the outside. The connection terminal 72 may be exposed to the outside through the terminal hole 62 formed in the third housing 60. Accordingly, the terminal hole 62 of the third housing 60 may be formed in a shape corresponding to the size and shape of the connection terminal 72.

In this embodiment, the connection terminal 72 is made of a conductive member and may be physically/electrically connected to at least one of the bus bars 80.

The bus bar 80 may be formed in the form of a conductive metal plate and coupled to the outer surface of the insulating frame 71. The battery cells 10 may be electrically connected to each other through the bus bar 80. For this purpose, the bus bar 80 may be provided with a plurality of through slits 81 into which the electrode leads 15 are inserted, and the electrode leads 15 are inserted into the through slits 81 of the bus bar 80. After being inserted, it can be joined to the bus bar 80 through a method such as welding. Accordingly, as shown in FIG. 4, at least a portion of the end of the electrode lead 15 may completely penetrate the bus bar 80 and be exposed to the outside of the bus bar 80.

A plurality of bus bars 80 may be arranged in parallel and spaced apart along the stacking direction of the battery cells 10, and at least two battery cells 10 may be coupled to one bus bar 80.

The bus bar cover 90 may be made of an insulating material such as resin and may be disposed between the bus bar assembly 70 and the third housing 60. Therefore, the bus bar cover 90 can be arranged so that one side faces the bus bar assembly 70 and the other side faces the third housing 60, and the bus bar cover 70 is formed to cover the entire bus bar 80. ) can be combined.

The bus bar cover 90 may be provided to ensure insulation between the bus bar 80 and the third housing 60. Therefore, the bus bar cover 90 can be formed in various shapes as long as it covers the entire bus bars 80.

Busbar cover 90 may include at least one terminal hole 92. The terminal hole 92 of the bus bar cover 90, like the terminal hole 62 of the third housing 60, is provided to expose the connection terminal 72 to the outside of the battery device 100, and the connection terminal 72 is provided to the outside of the battery device 100. (72) can be formed in a size that can penetrate.

At least a portion of the bus bar cover 90 of this embodiment may be disposed below the connection terminal 72 to support the connection terminal 72. However, the configuration of the present invention is not limited to this.

As shown in FIG. 4, the edge of the bus bar cover 90 of this embodiment and the periphery of the terminal hole 92 are in surface contact with the inner surface of the third housing 60, and the bus bar cover 90 and the third housing 60 are in surface contact. 3 A sealing member 95 may be interposed between the contact surfaces of the housing 60. The sealing member 95 may include a gasket or O-ring. To this end, at least one of the bus bar cover 90 or the third housing 60 may be provided with a groove into which the sealing member 95 can be inserted on the contact surface.

The sealing member 95 prevents the liquid flame-retardant member 85, which will be described later, from flowing into the battery cell 10 when the liquid form is injected between the bus bar cover 90 and the third housing 60. It can be prepared to prevent this from happening. Therefore, if the flame retardant member 85 is not formed by injecting liquid, the sealing member 95 may be omitted. also the city

The bus bar cover 90 may be joined to the third housing 60 through an adhesive. However, it is not limited to this, and various modifications are possible, such as configuring the joint surface to be pressed when the third housing 60 is coupled to the first and second housings 50 and 40.

The flame retardant member 85 is disposed between the bus bar assembly 70 and the third housing 60 to prevent explosion by-products such as flames or high-temperature gases or flames from spreading toward the third housing 60 during thermal runaway. there is.

To this end, the flame retardant member 85 may be formed of a member having flame retardancy or flame retardancy. Here, flame retardant performance refers to the ability to prevent the spread of combustion, and flame retardant performance refers to the ability to prevent combustion even if a fire occurs. Therefore, the flame retardant member 85 may have combustibility to a degree that does not cause combustion to spread, or may have non-flammable properties. For example, the flame retardant member 85 of this embodiment may be formed of a material with an ignition point of 700°C or higher.

The flame retardant member 85 of this embodiment may be formed to fill the space between the bus bar cover 90 and the first surface of the housing 30. For example, the flame retardant member 85 may be formed of a fire-resistant adhesive that is injected in liquid form into the space between the bus bar cover 90 and the third housing 60 and then hardened. In this case, an injection port for injecting the flame retardant member 85 may be provided in the third housing 60.

Since the sealing member 95 is interposed between the bus bar cover 90 and the third housing 60, an unnecessary gap is not formed between the bus bar cover 90 and the third housing 60, and thus the flame retardant member ( 85), the liquid flame retardant member 85 filled in the space between the bus bar cover 90 and the third housing 60 can be hardened within the space without leaking to the outside.

The hardened flame retardant member 85 may be formed in the form of foam, but is not limited thereto. In addition, it is also possible to separately prepare a flame retardant member 85 in a solid state and then insert it between the bus bar cover 90 and the third housing 60, instead of using the injection method described above.

The flame retardant member 85 of this embodiment may include mica or silicone, and may include fire-resistant urethane foam, flame-retardant rubber foam insulation, mineral wool, ceramic wool, glass wool, polyester wool, waste fiber wool, It is also possible to form one selected from flame retardant silicone foam, flame retardant polyurethane foam, flame retardant PE foam, flame retardant EVA foam, flame retardant EPDM foam, and flame retardant organic compound foam.

In the battery device according to the present embodiment described above, the flame prevention member 85 is disposed between the cell stack 1 and the third housing 60 where the connection terminal 72 is disposed. Therefore, even if one of the battery cells 10 explodes and explosion by-products are discharged, the explosion by-products can be suppressed from spreading toward the connection terminal 72 by the flame prevention member 85. In this case, explosion by-products may be discharged to the outside through the venting hole 45 of the second housing 40.

As described above, in the battery device 100 of this embodiment, the blocking member 48 is disposed on the second housing 40 that forms the second surface of the housing 30. When the internal pressure of the battery device 100 increases, the fracture portion 49 of the blocking member 48 of this embodiment may be broken and explosion by-products may be discharged to the outside of the battery device 100. At this time, when any one of the plurality of broken parts 49 is broken, explosion by-products are discharged through the broken part 49 and the corresponding vent hole 45, and the internal pressure is reduced, so that the other broken parts 49 can remain unbroken. Accordingly, the blocking member 48 can block explosion by-products discharged to the outside of the battery device 100 from flowing into the other battery cell 10 through the other vent hole 45.

Meanwhile, in the above-described embodiment, a case where a bus bar cover is provided is given as an example, but the bus bar cover 90 may be omitted as needed. In this case, the flame retardant member 85 may be filled in the space between the bus bar assembly 70 and the third housing 60.

When the bus bar cover 90 is omitted, insulation between the bus bar 80 and the third housing 60 must be secured, so the flame retardant member 85 may be formed of an insulating material. In addition, as the bus bar cover 90 is omitted, when the liquid flame retardant member 85 is injected between the bus bar assembly 70 and the third housing 60, the solution is in direct contact with the bus bar 80. can do. Therefore, when the bus bar cover 90 is omitted, the flame retardant member 85 can be manufactured as a solid insulating structure and then inserted between the bus bar assembly 70 and the third housing 60.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible without departing from the technical spirit of the present invention as set forth in the claims. This will be self-evident to those with ordinary knowledge in the field. Additionally, each embodiment may be implemented in combination with each other.

1: Cell stack
10: battery cell
30: case
40: second housing
50: first housing
60: third housing
70: Busbar assembly
80: bus bar
85: Flame retardant member
90: Busbar cover
95: Sealing member

Claims (11)

A cell stack in which multiple battery cells are stacked;
A bus bar assembly coupled to the cell stack to electrically connect the plurality of battery cells to each other;
a housing accommodating the cell stack and the bus bar assembly therein; and
a flame retardant member disposed between the bus bar assembly and the housing to block the spread of flame;
A battery device containing a.
According to paragraph 1,
A connection terminal electrically connected to the outside is disposed on the first side of the housing,
The battery device wherein the flame retardant member is disposed between the bus bar assembly and the first surface of the housing.
According to paragraph 2,
Further comprising a bus bar cover disposed between the bus bar assembly and the housing,
A battery device wherein the flame retardant member is disposed between the bus bar cover and the housing.
The method of claim 3, wherein the flame retardant member is:
A battery device that is a fireproof adhesive that is injected in liquid form between the busbar cover and the housing and then hardened.
According to paragraph 4,
The bus bar cover has an edge in surface contact with the inner surface of the housing,
The battery device further includes a sealing member interposed between the bus bar cover and a contact surface of the housing.
According to clause 5,
A battery device wherein the sealing member includes a gasket or O-ring.
The method of claim 1, wherein the flame retardant member is:
A battery device made of a material with an ignition point of 700°C or higher.
According to paragraph 2,
A battery device wherein the housing has at least one venting hole formed on a second surface disposed on an upper portion of the cell stack.
According to clause 8,
Further comprising a blocking member coupled to the second surface of the housing,
The blocking member is a battery device coupled to the second surface of the housing in a form that blocks the at least one venting hole.
The method of claim 9, wherein the blocking member is:
A battery device that includes any one of fire-resistant foam pad, metal foam, and ceramic wool, and allows gas to pass through and flame to block.
According to clause 9,
The blocking member is formed of a mica sheet,
A battery device in which a fractured portion that fractures at a lower pressure than other portions is formed in a region of the blocking member corresponding to the venting hole.

Images