KR20220103012A - Battery module - Google Patents

Abstract

Provided is a battery module including: a plurality of secondary battery cells including an electrode lead unit connected to an electrode assembly, a terrace unit forming an edge of a cell body member in which the electrode assembly is accommodated, and a sealing unit connected to the terrace unit; a housing unit for accommodating the plurality of secondary battery cells therein; and a guard unit having a first region facing at least a part of the terrace unit to delay swelling or bursting of the sealing unit of the at least one secondary battery cell, wherein the guard unit has a shape in which a first gap, which is a distance between inner surfaces of the first region, is smaller than the thickness of the cell body member to limit the expanded thickness of the terrace unit.

Description

Battery module

The present invention relates to a battery module.

As technology development and demand for mobile devices and electric vehicles increase, the demand for secondary battery cells as an energy source is rapidly increasing. The secondary battery cell is a battery capable of repeating charging and discharging because mutual conversion between chemical energy and electrical energy is reversible.

The secondary battery cell includes an electrode assembly such as a positive electrode, a negative electrode, a separator and an electrolyte, which are main components of the secondary battery, and a cell body member of a laminated film casing for protecting the electrode assembly.

In addition, a plurality of the secondary battery cells are mounted to be installed as a battery module in an electric vehicle, an energy storage system (ESS), or the like.

However, the electrode assembly generates heat while undergoing charging and discharging, and the temperature rise due to such heat deteriorates the performance of the secondary battery cell.

In addition, as gas is generated in any one of the secondary battery cells due to an internal factor of the battery module, such as a temperature rise of the secondary battery cell, the secondary battery cell may explode due to an increase in internal pressure. Accordingly, a problem in that the secondary battery cells in the battery module sequentially explode may occur.

That is, as gas is generated inside the secondary battery cell, the terrace portion of the secondary battery cell swells first, then expands to the sealing portion (fusion portion) of the secondary battery cell, which is a heat-sealed portion, and swells and bursts.

However, in the conventional battery module, there is a problem in that venting due to the bursting of the sealing portion proceeds relatively quickly after the terrace portion starts to swell. That is, the conventional battery module has a problem in that the terrace portion of the secondary battery cell is inflated first, and then the sealing portion is rapidly opened (bursted) due to the force applied from the inflated terrace portion to the sealing portion.

If the venting time is fast as in the prior art, the electrolyte in the secondary battery cell evaporates and the capacity decreases accordingly, so that the lifespan of the secondary battery cell and the battery module is greatly reduced.

An object of the present invention is to provide a battery module capable of delaying venting of gas inside a secondary battery cell.

A battery module according to an embodiment of the present invention includes an electrode lead part connected to an electrode assembly, a terrace part forming an edge of a cell body member in which the electrode assembly is accommodated, and a sealing part connected to the terrace part. of secondary battery cells; a housing unit accommodating the plurality of secondary battery cells therein; and a guard unit including a first area facing at least a portion of the terrace portion to delay swelling or bursting of the sealing portion of the at least one secondary battery cell, wherein the guard unit includes, the terrace portion The first interval, which is a distance between the inner surfaces of the first region, may have a shape smaller than the thickness of the cell body member to limit the expansion thickness.

In an embodiment, the first interval may have a constant value within the first region.

In an embodiment, the first interval may vary within the first region, and an average value of the first interval may have a value smaller than a thickness of the cell body member. In this case, the maximum value of the first interval may have a value smaller than the thickness of the cell body member.

In an embodiment, the first interval may have a value greater than a thickness of the terrace portion.

The battery module according to an embodiment of the present invention further includes a bus bar member to which the electrode lead portions of the plurality of secondary battery cells are electrically connected, wherein the guard unit has a bar shape, and the It may be disposed between the terrace portion in a state separated from the bus bar member.

In an embodiment, the guard unit includes the first area and a second area installed to face the sealing part, and the first interval may vary within the first area. In this case, the minimum value of the first interval may be smaller than the second interval or have the same value as the second interval.

In an embodiment, the average value of the first interval may have a greater value than the second interval.

In one embodiment, the guard unit may include: a first block member having a slit hole into which the sealing part is inserted; and a second block member having an opening facing at least a portion of the terrace portion, wherein the first region may be formed over the opening and the slit hole.

In an embodiment, the guard unit includes the first area and a second area installed to face the sealing part, and a second interval that is a distance between the inner surfaces of the second area is the first interval and It can have the same or greater value. In this case, at least one of the first interval and the second interval may have a value that varies within each region, and the average value of the second interval may have a value equal to or greater than the average value of the first interval.

In one embodiment, the guard unit may include: a first block member having a slit hole facing at least a portion of the sealing part; a second block member having an opening facing at least a portion of the terrace portion; and an intermediate block member positioned between the first block member and the second block member and formed with a connection opening for accommodating the sealing part and the terrace part together.

In one embodiment, the guard unit may include a plurality of unit units disposed between terrace portions of adjacent secondary battery cells, and the plurality of unit units may be integrated to form an integrated guard unit.

The battery module according to an embodiment of the present invention further includes at least one bus bar member having the integrated guard unit embedded therein, wherein the electrode lead portions of the plurality of secondary battery cells are electrically connected to the bus bar member. can be connected to

The battery module according to an embodiment of the present invention further includes a bus bar member to which the electrode lead parts of the plurality of secondary battery cells are electrically connected, wherein the guard unit is separated from the bus bar member. It may be disposed between the terrace parts. Alternatively, the guard unit may be disposed between the terrace parts in a state in which the guard unit is coupled to the bus bar member.

In one embodiment, the guard unit, based on the longitudinal direction of the cell body member, may have a shape that faces 50% or more of the total length of the terrace portion and the sealing portion.

In an embodiment, the guard unit may be installed to face a portion of the sealing portion where the electrode lead portion is disposed.

The battery module of the present invention has an advantage in that it is possible to delay the venting of the gas by bursting the sealing portion of the secondary battery cell.

Accordingly, the battery module of the present invention has an effect of delaying the explosion of the secondary battery cell due to gas venting.

In addition, by delaying the time when the sealing part bursts, the time at which the electrolyte in the secondary battery cell is evaporated is also delayed, thereby improving the problem of a sudden decrease in the capacity of the secondary battery cell.

In another aspect, the battery module of the present invention has the advantage of being able to prevent an explosion due to sudden gas venting by intentionally constantly venting the gas generated in the secondary battery cell.

However, the various and beneficial advantages and effects of the present invention are not limited to the above, and will be more easily understood in the course of describing specific embodiments of the present invention.

1 is an exploded perspective view of a battery module according to an embodiment of the present invention.
2 is a perspective view showing only one secondary battery cell and a guard unit corresponding thereto in a battery module according to an embodiment of the present invention.
3 is a cross-sectional view showing only a guard unit and a secondary battery cell in the battery module according to an embodiment of the present invention.
4 is a cross-sectional view illustrating a state in which the terrace portion of the secondary battery cell in FIG. 3 is inflated.
5 is a cross-sectional view illustrating a case in which the guard unit includes an expansion guide member in the battery module according to an embodiment of the present invention.
6 is a cross-sectional view illustrating a state in which the terrace portion of the secondary battery cell in FIG. 5 is inflated.
7 is a cross-sectional view showing an enlarged portion "A" in FIG.
8 is a cross-sectional view illustrating a modified embodiment in which the needle member is in the form of a tube in FIG. 7 .
9 is a cross-sectional view showing an enlarged portion "B" in FIG.
10 is a cross-sectional view illustrating a state in which a plurality of guard units and secondary battery cells shown in FIG. 3 are installed.
11(a) to 11(c) are side views showing a state in which the guard unit is coupled to the secondary battery cell, and FIG. 11(a) shows the guard unit and the secondary battery cell shown in FIG. 2, 11(b) and 11(c) show a modified example in which the height of the guard unit is increased compared to FIG. 11(a).
12 to 16 are cross-sectional views showing various modifications of the guard unit.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. The shapes and sizes of elements in the drawings may be exaggerated for clearer description.

Also, in this specification, the singular expression includes the plural expression unless the context clearly dictates otherwise, and the same reference signs or reference signs assigned in a similar manner throughout the specification refer to the same element or corresponding element. do it by doing

1 is an exploded perspective view of a battery module according to an embodiment of the present invention. Referring to the drawings, the battery module according to an embodiment of the present invention includes a plurality of secondary battery cells 10 and a housing unit 20. ), it may include a guard unit (30).

Here, the plurality of secondary battery cells 10 form an edge of a cell body member 10a in which an electrode assembly (not shown) is accommodated, an electrode lead 11 connected to the electrode assembly, and a cell body member 10a, , The terrace portion 12, which is a portion in which the pouch-shaped member accommodating the electrode assembly is in contact with each other, and the sealing portion (fusion portion) connected to the outside of the terrace portion 12 and sealing or heat-sealing the pouch-type member in contact with each other ( 13) may be included. The sealing part 13 may be positioned between the electrode lead part 11 and the cell body member 10a exposed to the outside. The housing unit 20 may include at least one bus bar member 21 to which the electrode lead part 11 is coupled. The bus bar member 21 may be electrically connected to the electrode lead portions 11 of the plurality of secondary battery cells 10 . A plurality of secondary battery cells 10 may be accommodated in a stacked state inside the housing unit 20 . The guard unit 30 may be provided on the bus bar member 21 as an example. The guard unit 30 may delay swelling or bursting of the sealing part 13 when gas is generated inside the secondary battery cell 10 . Here, the guard unit 30 may have an integrated structure to correspond to each of the plurality of secondary battery cells 10 , and the integrated guard unit 30 may be installed on the bus bar member 21 . That is, the integrated guard unit 30 may be embedded in the bus bar member 21 .

Accordingly, in the battery module according to an embodiment of the present invention, the sealing part 13 of the secondary battery cell 10 may burst and thereby delay gas venting. It is possible to delay the explosion of the secondary battery cell 10 .

In addition, as the battery module of the present invention delays the time when the sealing part 13 is burst, the time at which the electrolyte in the secondary battery cell 10 is evaporated is also delayed, so that the capacity of the secondary battery cell 10 is drastically reduced. problem can be improved.

For example, under the condition that the secondary battery cell 10 is 100% charged and the temperature is 60° C., the conventional battery module maintains a lifespan of about 42 days, while the present invention including the guard unit 30 's battery module was able to maintain a lifespan of about 191 days. Based on this, in the case of the battery module according to the embodiment of the present invention, it was found that there is an effect of extending the life.

Here, the secondary battery cell 10 may include an electrode assembly and a cell body member 10a surrounding the electrode assembly.

The electrode assembly is used by being accommodated in the cell body member 10a together with substantially including an electrolyte. The electrolyte may contain lithium salts such as LiPF ₆ and LiBF ₄ in an organic solvent such as EC (ethylene carbonate), PC (propylene carbonate), DEC (diethyl carbonate), EMC (ethyl methyl carbonate), DMC (dimethyl carbonate), etc. can Furthermore, the electrolyte may be in a liquid, solid or gel form.

And, the cell body member (10a) is configured to protect the electrode assembly, and to accommodate the electrolyte. For example, the cell body member (10a) may be provided as a pouch-shaped member or a can-shaped member. Here, the pouch-type member may have a shape to accommodate the electrode assembly by covering the electrode assembly with a film casing and sealing the edges of the casing on three or four surfaces. For example, a pouch-type member of a three-sided sealing structure is stacked in a state in which the electrode assembly is accommodated in the receiving space formed in a single sheet of exterior material, and then the three surfaces of the upper and both sides are bonded except for one surface (for example, the lower surface). will be sealed In addition, the can-shaped member is a member configured to normally seal and accommodate the electrode assembly on one surface, and is mainly configured to seal one surface of the upper surface in a state in which the electrode assembly is accommodated therein.

However, these pouch-type secondary battery cells 10 and can-type secondary battery cells 10 are only examples of the secondary battery cells 10 accommodated in the battery module of the present invention, and secondary battery cells accommodated in the battery module of the present invention. (10) is not limited to this kind.

In addition, the secondary battery cell 10 may include a terrace portion 12 forming an edge of the cell body member 10a surrounding the electrode assembly. The edge of the cell body member (10a) is a portion where the exterior material is overlapped. In addition, the secondary battery cell 10 may be provided with a sealing portion 13 for sealing or heat-sealing the overlapping portion of the exterior material.

In the detailed description and claims, the terrace portion 12 is defined to mean a portion excluding the sealing portion 13 among the edges of the cell body member 10a. That is, the edge of the cell body member 10a (the portion where the exterior material is overlapped) may be composed of a terrace portion 12 and a sealing portion 13 connected thereto.

The electrode lead part 11 is exposed to the outside of the exterior material through the terrace part 12 and the sealing part 13 .

The sealing part 13 may be sealed (fused) to the outside of the terrace part 12 to seal the edge of the cell body member 10a. In addition, in the portion where the electrode lead part 11 is located, the sealing part 13 may seal the electrode lead part 11 together with the edge of the cell body member 10a.

Here, to be sealed (fusion-bonded) means to be solidified and combined in a pressurized state after being melted by heat or the like. In addition, the sealing part 13 may be sealed with an adhesive material such as a sealant.

In addition, the secondary battery cell 10 of the battery module according to an embodiment of the present invention is disposed between the edge of the cell body member 10a (the portion where the exterior material is overlapped and abutted) and the electrode lead portion 11. An insulating member (not shown) may be included. That is, the insulating member may have a structure covering the electrode lead part 11 . Accordingly, the edge of the cell body member 10a may be electrically separated from the electrode lead part 11 and insulated.

The housing unit 20 serves as a body of a battery module in which the plurality of secondary battery cells 10 are accommodated.

That is, the housing unit 20 has a configuration in which a plurality of secondary battery cells 10 are installed. It serves to transfer the electric energy to the secondary battery cell (10).

To this end, the housing unit 20 includes a bus bar member 21 that is connected to the electrode lead 11 of the secondary battery cell 10 and electrically connects the secondary battery cell 10 to the outside. can do.

Also, the housing unit 20 may include a bottom member 22 accommodating the plurality of secondary battery cells 10 .

Here, the floor member 22 may have an insulating member applied to the front end portion and the rear end portion coupled to the bus bar member 21 , or may be attached in the form of a sheet. This is to secure the insulation of the bus bar member 21 .

In addition, the bottom member 22 may be configured such that a heat transfer material is applied to a portion in contact with the secondary battery cell 10 so that heat transfer between the secondary battery cell 10 and the secondary battery cell 10 occurs more effectively. However, this is only an example, and a heat transfer material is not provided between the bottom member 22 and the secondary battery cell 10 of the present invention, and the secondary battery cell 10 may be in direct contact with the bottom member 22 . .

In addition, the housing unit 20 may include a side wall member 24, a front member 25, a rear member 26, a cover member 23, etc. in order to accommodate the secondary battery cell 10 in a surrounding shape. can

Here, the bottom member 22 may be disposed at the lower end of the secondary battery cell 10 . The side wall member 24 may be provided at a corner of the bottom member 22 . The front member 25 may be provided in front of the housing unit 20 and may be connected to a front bus bar member 21 coupled to one electrode lead part 11 of the secondary battery cell 10 . . The rear member 26 may be provided at the rear of the housing unit 20 and may be connected to the rear bus bar member 21 coupled to the other electrode lead 11 of the secondary battery cell 10 . . The cover member 23 is provided on the upper ends of the side wall member 24 , the front member 25 , and the rear member 26 , and may be configured to protect the upper end of the secondary battery cell 10 .

Here, the bottom member 22 may be configured to transfer heat generated in the secondary battery cell 10 to an external heat sink to cool it. The side wall member 24 may also discharge heat generated in the secondary battery cell 10 to the outside.

In addition, the housing unit 20 is provided with a buffer pad member between the secondary battery cells 10 or between the secondary battery cell 10 and the side wall member 24, so that the secondary battery cell 10 is swollen. (Swelling) may be configured to buffer.

The guard unit 30 serves to delay swelling or bursting of the sealing part 13 of the secondary battery cell 10 . The guard unit 30 will be described with reference to FIGS. 2 to 4 .

FIG. 2 is a perspective view showing only one secondary battery cell 10 and a corresponding guard unit 30 in the battery module according to an embodiment of the present invention, and FIG. 3 is a perspective view according to an embodiment of the present invention It is a cross-sectional view showing only the guard unit 30 and the secondary battery cell 10 in the battery module, and FIG. 4 is a cross-sectional view showing a state in which the terrace portion 12 of the secondary battery cell 10 in FIG. 3 is inflated. For convenience and clarity of illustration, the secondary battery cell 10 is illustrated in FIGS. 3 and 4 .

2 to 4 , the guard unit 30 may be configured such that the expansion of the terrace part 12 is possible within a limited range, but the expansion of the sealing part 13 can be reduced as much as possible. That is, in the guard unit 30, the gap G1 with the sealing part 13 is smaller than the gap G2 with the terrace part 12, so that the space for the expansion of the terrace part 12 is a cell. It is configured to provide a relatively small space for expansion of the sealing part 13 while providing it in a range smaller than the thickness T3 of the body member 10a.

In this case, while the gas generated inside the secondary battery cell 10 is accommodated in a space secured by the expansion of the terrace part 12 , the sealing of the sealing part 13 can be maintained. Accordingly, it is possible to prevent the secondary battery cell 10 from explosion due to gas venting. The guard unit 30 of the battery module according to an embodiment of the present invention includes a first block member 31 and a second block member. (32) may be included.

Here, a slit hole 31a into which the sealing part 13 is inserted may be formed in the first block member 31 . The second block member 32 is provided integrally with the first block member 31 , and may face the terrace portion 12 . An opening 32a through which the sealing part 13 and the terrace part 12 are introduced may be formed in the second block member 32 . In addition, the gap G1 between the sealing part 13 and the inner surface of the slit hole 31a is smaller than the gap G2 between the terrace part 12 and the inner surface of the second block member 32 . can be

That is, since the gap G1 between the first block member 31 and the sealing part 13 is relatively small, the expansion of the sealing part 13 is suppressed, while the second block member 32 and the sealing part 13 are separated from each other. Since the gap G2 between the terrace portions 12 is relatively large, the expansion of the terrace portion 12 is possible within the space between the inner surfaces of the first block member 32 .

Accordingly, while the gas generated inside the secondary battery cell 10 is accommodated in a space secured by the expansion of the terrace part 12 , the sealing of the sealing part 13 can be maintained.

Here, the gap G1 between the sealing part 13 and the inner surface of the slit hole 31a of the battery module according to an embodiment of the present invention is the sealing part 13 through the slit hole 31a. It may be at least 0.5 times or less of the inserted length (L).

That is, in the battery module according to an embodiment of the present invention, there may also be a gap G1 between the sealing part 13 and the slit hole 31a of the first block member 31, and this gap G1 ) is defined as above.

Accordingly, the sealing part 13 may also expand by the gas generated in the secondary battery cell 10 . However, the distance G1 at which the sealing part 13 can expand, which is the distance G1 between the sealing part 13 and the slit hole 31a, is the insertion length L of the sealing part 13 . 0.5 times or less. In addition, when the sealing part 13 is split due to the inflow of gas, it is gradually divided from one end of the sealing part 13 coupled to the terrace part 12 to the other end of the sealing part 13 adjacent to the outside. will lose

And the maximum distance that one end of the sealing portion 13 can be separated from the original position while one end of the sealing portion 13 is split is the gap G1 between the sealing portion 13 and the slit hole 31a. do. In addition, this gap (G1) is less than 1/2 of the insertion length (L) of the sealing portion (13).

Therefore, even if one end of the sealing part 13 is maximally split, the other end of the sealing part 13 is not split, so that the sealing can be maintained at the other end of the sealing part 13 .

3 and 4 , the guard unit 30 may be divided into a first area A1 corresponding to the terrace portion 12 and a second area A2 facing the sealing portion 13 . . That is, the guard unit 30 may be installed to face at least a portion of the terrace portion 12 and at least a portion of the sealing portion 13 . At this time, the first interval T1, which is the distance between the inner surfaces in the first area A1, corresponds to the space in which the terrace part 12 can expand, and is the distance between the inner surfaces in the second area A2. The second gap T2 corresponds to a space in which the sealing part 13 can expand. Since the guard unit 30 is provided with the second block member 32 forming the opening 32a, due to the thickness of the second block member 32, it is between the inner surface in the area A1 facing the terrace portion 12. The interval T1 is smaller than the thickness T3 of the cell body member 10a. Accordingly, the expanded thickness of the terrace portion 12 may be limited by the interval T1 between the inner surfaces of the area A1 facing the terrace portion 12 .

The battery module according to the prior art has a problem in that the terrace portion of the secondary battery cell is inflated first, and then the sealing portion is rapidly opened (bursted) due to the force applied from the inflated terrace portion to the sealing portion. However, according to the embodiment of the present invention, since the expanded thickness of the terrace portion 12 is limited within a certain range (ie, T1), the phenomenon in which the sealing portion 13 is rapidly opened due to excessive expansion of the terrace portion 12 is reduced. It is possible to delay the gas venting accordingly.

In addition, due to the thickness of the first block member 31, the guard unit 30 has a thickness T3 between the inner surfaces of the guard unit 30 in the area A2 facing the sealing portion 13 (T2) of the cell body member 10a. ) can be formed smaller than Accordingly, the range in which the sealing part 13 can expand may be limited.

And, as shown in FIGS. 3 and 4 , in the guard unit 30 , the gap T2 between the inner surfaces in the area A2 facing the sealing part 13 faces the terrace part 12 . It may be formed to be smaller than the interval T1 between the inner surfaces of the region A1.

In addition, the interval T1 between the inner surfaces in the area A1 facing the terrace portion 12 so that the terrace portion 12 can be introduced into the opening 32a of the guard unit 30 is equal to that of the terrace portion 12 . It may have a value greater than the thickness.

On the other hand, the guard unit 30 has a gap T1 between the inner surfaces in the area A1 facing the terrace portion 12 and/or the space between the inner surfaces in the area A2 facing the sealing portion 13 . (T2) may have a changing structure (see FIGS. 5 and 6). In this way, when the intervals (T1, T2) between the inner surfaces of the guard member 30 change, each average interval may be considered. That is, the average distance between the inner surfaces in the area A2 facing the sealing portion 13 may be formed to be smaller than the average distance between the inner surfaces in the area A1 facing the terrace portion 12 . In this case, the average interval (average value) may be defined as a value obtained by integrating the intervals T1 and T2 between the inner surfaces of the guard member 30 by dividing a value obtained by integration by the length of each region.

In addition, the guard unit 30 constant expansion of the terrace portion 12 and the sealing portion 13 in the area A1 facing the terrace portion 12 and the area A2 facing the sealing portion 13. limited within the scope. At this time, the expansion limit length LC of the terrace portion 12 and the sealing portion 13 of the guard unit 30 is based on the longitudinal direction (X1 direction) of the cell body member 10a, the terrace portion 12 and It corresponds to the sum of the lengths corresponding to the sealing portion (13).

In this case, in order to limit the expansion range of the terrace portion 12, the guard unit 30 may have a shape that faces at least half of the entire length LA of the terrace portion 12 and the sealing portion 13. . That is, the expansion limit length LC of the guard unit 30 may have a value of 50% (half) or more of the total length LA of the terrace portion 12 and the sealing portion 13 . In addition, the expansion limit length LC of the guard unit 30 is 60% or more, 70% or more, 80% or more, or 90% or more of the total length LA of the terrace part 12 and the sealing part 13. may have When the expansion limit length LC is shortened, the distance LD between the side surface of the cell body member 10a and the guard unit 30 increases, and accordingly, the area of the terrace portion 12 in which the expansion thickness is not limited. this will increase

In addition, the guard unit 30 may be installed to face the entire sealing portion 13 to limit the expansion of the entire sealing portion (13).

And, the second block member 32 of the battery module according to an embodiment of the present invention, the edge adjacent to the cell body member (10a) of the portion facing the terrace portion 12 is formed in a curved shape with a concave shape. can

As described above, since the second block member 32 has a concave curved shape on the edge side adjacent to the cell body member 10a, it is possible to further secure the expansion space of the terrace part 12 .

In addition, since the second block member 32 includes a concave curved surface shape on the edge side adjacent to the cell body member 10a, the terrace portion 12 is formed at a corner portion when the terrace portion 12 is expanded. It is possible to prevent the problem of sticking and bursting.

In addition, the second block member 32 of the battery module according to an embodiment of the present invention may be provided on both sides of the terrace portion 12, respectively. Therefore, the distance T1 between the inner surfaces in the area A1 facing the terrace portion 12 due to the thickness of the second block member 32 is smaller than the thickness T3 of the cell body member 10a. will have

Accordingly, the second block member 32 can induce the expansion shape of the terrace part 12 while securing some expansion spaces on both sides of the terrace part 12 . That is, the second block member 32 may induce uniform expansion of both sides of the terrace portion 12 without asymmetrical expansion of one side of the terrace portion 12 . Accordingly, it is possible to secure the maximum expansion space while preventing swelling or bursting of the terrace portion 12 .

5 is a cross-sectional view illustrating a case in which the guard unit 30 includes the expansion guide member 33 in the battery module according to an embodiment of the present invention, and FIG. 6 is a terrace of the secondary battery cell 10 in FIG. It is a cross-sectional view showing the state in which the part 12 is inflated. For convenience and clarity of illustration, the secondary battery cell 10 is illustrated in FIGS. 5 and 6 .

Referring to the drawings, the guard unit 30 of the battery module according to an embodiment of the present invention may further include an expansion guide member 33 . The guard unit 30 shown in FIGS. 5 and 6 has the same configuration as the guard unit 30 described with reference to FIGS. 2 to 4 , except that it additionally includes an expansion guide member 33 . Accordingly, in order to avoid unnecessary duplication, descriptions of the same or similar components will be omitted and the descriptions of FIGS. 2 to 4 will be substituted.

One end of the expansion guide member 33 is coupled to the first block member 31 , and the other end is formed to extend to the second block member 32 , and as the terrace portion 12 expands, The other end may be elastically moved in the direction of the second block member 32 . That is, the expansion guide member 33 may be elastically moved in the thickness direction (X2) of the cell body member (10a).

In this way, by the expansion guide member 33, the expansion of the terrace portion 12 can be guided during expansion. That is, the expansion shape and expansion pressure of the terrace part 12 can be adjusted by the expansion guide member 33 .

Accordingly, it is possible to prevent the terrace portion 12 from bursting due to an impact caused by the sudden expansion of the terrace portion 12 . That is, by guiding the terrace portion 12 to gradually expand, swelling or bursting of the terrace portion 12 can be prevented.

In addition, the expansion guide member 36 may be limited in movement in a range smaller than the thickness of the cell body member 10a to limit the expanded thickness of the terrace portion 12 . That is, due to the thickness of the second block member 32 and the thickness of the expansion guide member 36, the gaps T1a and T1b between the inner surfaces in the area A1 facing the terrace portion 12 are the cell body member 10a. ) is larger than the thickness T3. Accordingly, the expanded thickness of the terrace portion 12 may be limited to a range smaller than the distances T1a and T1b between the inner surfaces in the area A1 facing the terrace portion 12 .

In addition, the guard unit 30 shown in FIGS. 5 and 6 has a shape in which the distances T1a and T1b between the inner surfaces in the area A1 facing the terrace portion 12 change. In this case, the average distance between the inner surfaces in the area A1 facing the terrace portion 12 may have a larger value than the average distance between the inner surfaces in the area A2 facing the sealing portion 13 .

And, the guard unit 30 has a gap T2 between the inner surfaces in the area A2 facing the sealing part 13, and the gap T2 between the inner surfaces in the area A1 facing the terrace part 12 ( It may be formed smaller than T1a, T1b).

The expansion guide member 33 of the battery module according to an embodiment of the present invention may be formed in a shape including a concave curved surface in a central portion facing the terrace portion 12 .

That is, since the expansion guide member 33 includes a concave curved shape on the edge side adjacent to the cell body member 10a, it is possible to further secure the expansion space of the terrace part 12 .

In addition, since the expansion guide member 33 includes a concave curved shape on the edge side adjacent to the cell body member 10a, the terrace part 12 is in close contact with the edge part when the terrace part 12 is expanded. This will prevent the popping problem.

7 is a cross-sectional view showing an enlarged portion "A" in FIG. 6, and FIG. 8 is a cross-sectional view showing a modified embodiment in which the needle member 34 in FIG. 7 is in the form of a tube.

Referring to the drawings, the guard unit 30 of the battery module according to an embodiment of the present invention may further include a needle member 34 .

Here, the needle member 34 is coupled to the second block member 32, and protrudes in the direction of the terrace portion 12, so as to open the expanded terrace portion 12, the expansion guide member ( 33) may be disposed to pass through the through hole (33a) formed in the.

As described above, the needle member 34 opens a part of the expanded terrace portion 12 to discharge the gas inside the terrace portion 12 to the outside.

The needle member 34 is a configuration for constantly venting the gas generated in the secondary battery cell 10 intentionally in the battery module of the present invention. That is, the needle member 34 opens the terrace portion 12 to prevent explosion caused by sudden gas venting.

And, the needle member 34 of the battery module according to an embodiment of the present invention is provided in the form of a tube having an inner hollow, an inlet hole 34a opened at the front tip is formed, and the middle portion is formed. A discharge hole (34b) for communicating the inner hollow and the outside may be formed.

As shown in FIG. 7, the needle member 34 may be provided in the form of a general column having no hollow inside, or may be provided in the form of a tube having an inner hollow as shown in FIG.

When the needle member 34 is provided in the form of a tube and the inlet hole 34a and the outlet hole 34b are formed, the gas inside the terrace part 12 passes through the inlet hole 34a. It can be discharged through the discharge hole (34b). That is, even if the needle member 34 does not separate after passing through the terrace portion 12 , the gas inside the terrace portion 12 can be discharged.

In addition, the guard unit 30 of the battery module according to an embodiment of the present invention may include a reinforcing pad member 35 .

Here, the reinforcing pad member 35 is provided on one surface of the expansion guide member 33 facing the terrace portion 12, and an adhesive material for adhering the expanding terrace portion 12 may be applied. .

As such, the reinforcing pad member 35 is adhered to the terrace portion 12 when the terrace portion 12 expands. In addition, since the terrace part 12 is adhered to the terrace part 12 even when the terrace part 12 is opened by the needle member 34, the opening part of the terrace part 12 is used as a starting point for the terrace part ( 12) It is possible to prevent the problem of tearing and bursting.

9 is an enlarged cross-sectional view of part "B" in FIG. 6, and with reference to the drawing, the guard unit 30 of the battery module according to an embodiment of the present invention may include a holding member 36. can

Here, the holding member 36 is provided on the second block member 32 , and the other end of the expansion guide member 33 moved in the direction of the second block member 32 may be caught and fixed.

That is, the holding member 36 is provided to fix the expansion guide member 33 , so that the expansion guide member 33 does not press the terrace part 12 after the terrace part 12 is expanded. do.

Accordingly, after intentional venting occurs, the shape of the inflated terrace portion 12 is maintained, thereby minimizing exposure of the open portion to the outside air.

On the other hand, if the holding member 36 is not provided, the terrace portion 12 pressed by the expansion guide member 33 returns to its original shape and the opening portion opened by the needle member 34 remains intact. are exposed Accordingly, oxygen flows into the secondary battery cell 10 due to the circulation of the secondary battery cell 10 and the outside air, or the electrolyte inside the secondary battery cell 10 leaks to the outside further aggravates the problem. do.

Therefore, by including the holding member 36 in the battery module of the present invention, it is possible to improve this problem.

To this end, specifically, the holding member 36 of the battery module according to an embodiment of the present invention may include a support tab portion 36a and a hook portion 36b.

Here, the support tab portion 36a may be coupled to the second block member 32 . One end of the hook portion 36b is hinged to the support tab portion 36a, and the other end is formed in a wedge shape to fit into the fixing hole 33b formed in the extension guide portion, and is attached to the support tab portion 36a. It can be pressed in the direction of the second block member 32 by the provided elastic member (36c).

Accordingly, as the terrace portion 12 is expanded and the extension guide member 33 approaches the second block member 32 , the other end of the extension guide member 33 is part of the hook portion 36b. It is moved between the other end and the outer surface of the second block member (32). In addition, when the other end of the extension guide member 33 is completely in close contact with the second block member 32 , the other end of the hook portion 36b in the wedge shape is formed at the other end of the extension guide member 33 . It is fitted to be caught in the fixing hole (33b).

10 is a cross-sectional view illustrating a state in which a plurality of the guard unit 30 and the secondary battery cells 10 shown in FIG. 3 are installed. 3 shows a state in which the guard units 30 are disposed on both sides of the terrace part 12 of one secondary battery cell 10, whereas in the case of FIG. 10, the guard unit 30 shown in FIG. It shows a state in which a plurality of unit units are connected. The embodiment of the guard unit 30 shown in FIG. 10 is the same as the embodiment of the guard unit 30 shown in FIG. 3 except that a plurality of unit units have an integrated shape, so the same or similar A detailed description of the configuration will be replaced with the above description, and only differences will be described.

As shown in FIG. 10 , the guard unit 30 includes a plurality of unit units disposed between the terrace portions 12 of adjacent secondary battery cells 10 , and the plurality of unit units are integrated with the guard unit 30 . ) can be formed. When the integrated guard unit 30 is used, it is possible to obtain the advantage that the installation of the guard unit 30 is easy. Also, the integrated guard unit 30 may be integrated with the bus bar member 21 to be embedded in the bus bar member 21 as shown in FIG. 1 .

Meanwhile, as shown in FIG. 10 , the guard unit 30 may be disposed between the bus bar member ( 21 in FIG. 1 ) to which the electrode lead part 11 is coupled and the terrace part 12 in a separated state. . That is, the guard unit 30 and the bus bar member 21 may be configured separately. Alternatively, the guard unit 30 may be disposed between the terrace units 12 in a state coupled to the bus bar member 21 (ie, an integrated state) as shown in FIG. 1 .

11 (a) to 11 (c) are side views illustrating a state in which the guard unit 30 is coupled to the secondary battery cell 10, and FIG. 11 (a) is the guard unit 30 shown in FIG. 2 . and the secondary battery cell 10 , and FIGS. 11 ( b ) and 11 ( c ) show a modified example in which the height of the guard unit 30 is increased compared to FIG. 11 ( a ).

As shown in FIG. 11( a ), the guard unit 30 may be installed to face the part where the electrode lead part 11 is disposed among the terrace part 12 and the sealing part 13 . In order for the guard unit 30 to fully correspond to the portion where the electrode lead part 11 is disposed, the height H1 of the guard unit 30 has a value greater than the height HL of the electrode lead part 11. can A portion of the sealing portion 13 to which the electrode lead portion 11 is exposed to the outside may have relatively weak bonding strength compared to other portions of the sealing portion 13 . The embodiment of the present invention limits the expansion of the terrace portion 12 through the guard unit 30 to delay the swelling or bursting of the sealing portion 13 in the portion where the electrode lead portion 11 is exposed to the outside. be able to

The height H1 of the guard unit 30 may have a value of half or more of the height H3 of the cell body member 10a, as shown in FIG. 11(b), as shown in FIG. 11(c). It is also possible to be installed to have a height similar to or the same as the height (H3) of the cell body member (10a). As such, when the height of the guard unit 30 is increased, it is possible to suppress the expansion of the terrace portion 12 in a large area, thereby delaying the swelling or bursting of the sealing portion 12 .

In addition, in order to limit the expansion range of the terrace portion 12, the guard unit 30 has a shape that faces at least 50% (half) of the total length LA of the terrace portion 12 and the sealing portion 13. can have The guard unit 30 may have a shape that faces 60% or more, 70% or more, 80% or more, or 90% or more of the total length LA. When the area that the guard unit 30 covers the terrace portion 12 decreases, the distance LD between the side surface of the cell body member 10a and the guard unit 30 increases, and accordingly, the expansion thickness is not limited. The area of the terrace part 12 is increased.

12 is a cross-sectional view showing a modified example of the guard unit (30). The guard unit 30 shown in FIG. 12 is different from the guard unit 30 shown in FIG. 10 only in that the positions of the terrace part 12 and the sealing part 13 have different structures. In order to avoid unnecessary duplication, detailed descriptions of the same or similar components will be replaced with those described with reference to FIGS. 3 and 10 .

The guard unit 30 shown in FIG. 12 may include a first area A1 facing at least a portion of the terrace portion 12 and a second area A2 facing the sealing portion 13 . have.

Since the first intervals T1a and T1b, which are the distances between the inner surfaces of the first region A1, have a shape smaller than the thickness T3 of the cell body member 10a, the expansion thickness of the terrace portion 12 is limited. Venting of the gas inside the battery cell 10 may be delayed. In addition, since the second interval T2 , which is the distance between the inner surfaces of the second region A2 , also has a smaller value than the thickness T3 of the cell body member 10a, the expansion thickness of the sealing part may be limited.

The first intervals T1a and T1b may vary within the first area A1 . That is, the distance T1a between the inner surface of the guard member 30 on one side close to the cell body member 10a in the first area A1 and the distance between the inner surface of the guard member 30 on the other side of the first area A1. (T1b) may have different values. In this case, the minimum value T1b of the first interval may have the same value as the second interval T2. That is, the distance T1b between the inner surfaces of the guard member 30 on the other side of the first area A1 close to the electrode lead part 11 may be equal to the second interval T2 . Also, the average value of the first interval may have a larger value than the second interval T2 . The average value of the first interval may be obtained from a value obtained by integrating the interval between the inner surfaces of the guard member 30 by dividing the value obtained by the integration by the length of the first area A1 .

The guard unit 30 includes a first block member 31 having a slit hole 31a into which the sealing part 13 is inserted, and a second block having an opening 32a facing at least a portion of the terrace part 12 . It includes a member 32 , wherein the first area A1 may be formed across the opening 32a and the slit hole 31a.

In the guard unit 30 shown in FIG. 12 , the expanded thickness of the terrace portion 12 may be limited by the first gaps T1a and T1b between the inner surfaces in the area A1 facing the terrace portion 12 . Accordingly, it is possible to reduce a phenomenon in which the sealing portion 13 is suddenly opened due to excessive expansion of the terrace portion 12 , and accordingly, it is possible to delay gas venting of the secondary battery cell 10 .

13 is a cross-sectional view showing another modified example of the guard unit (30). The guard unit 30 shown in FIG. 13 has a different arrangement of spacing between the inner surfaces of the first and second areas A1 and A2 when compared to the guard unit 30 shown in FIG. 12 . In order to avoid unnecessary duplication, detailed descriptions of the same or similar components will be replaced with those described with reference to FIGS. 3, 10 and 12 .

The guard unit 30 shown in FIG. 13 may include a first area A1 facing at least a portion of the terrace portion 12 and a second area A2 facing the sealing portion 13 . have.

Since the first intervals T1a and T1b, which are the distances between the inner surfaces of the first region A1, have a shape smaller than the thickness T3 of the cell body member 10a, the expansion thickness of the terrace portion 12 is limited. Venting of the gas inside the battery cell 10 may be delayed. In addition, since the second intervals T2a and T2b, which are the distances between the inner surfaces of the second region A2, also have a smaller value than the thickness T3 of the cell body member 10a, the expansion thickness of the sealing part can be limited. .

Here, the second intervals T2a and T2b may be equal to or greater than the first intervals T1a and T1b. Also, the minimum value T1a of the first interval may have a smaller value than the second interval T2a and T2b.

In addition, at least one of the first intervals T1a and T1b and the second intervals T2a and T2b may change within each of the regions A1 and A2. For example, a distance T1a between the inner surface of the guard member 30 on one side close to the cell body member 10a in the first area A1 and the inner surface of the guard member 30 on the other side of the first area A1. The distance T1b may have different values. In addition, the distance T2a between the inner surface of the guard member 30 on one side close to the cell body member 10a in the second area A1 and the distance between the inner surface of the guard member 30 on the other side of the second area A2. (T2b) may have different values. In this case, the average value of the first interval may have a value equal to or greater than the average value of the second interval. The average value of the first and second intervals may be obtained from a value obtained by integrating the intervals between the inner surfaces of the guard member 30 by dividing the values obtained by the integration by the lengths of the respective areas A1 and A2.

The guard unit 30 includes a first block member 31 having a slit hole 31a into which the sealing part 13 is inserted, and a second block having an opening 32a facing at least a portion of the terrace part 12 . It may include a member 32 and an intermediate block member 31 ′ positioned between the first block member 31 and the second block member 32 . A connection opening 31'a for accommodating the sealing part 13 and the terrace part 12 together may be formed in the intermediate block member 31'. In this case, both the first area A1 and the second area A2 may be positioned in the connection opening 31'a. Although FIG. 13 shows a configuration in which an inclined surface is formed in the connection opening 31'a, the connection opening 31'a may have a stepped structure between the opening 32a and the slit hole 31a. In addition, the guard unit 30 may be provided with only the first block member 31 and the second block member 32 without the intermediate block member 31 ′ shown in FIG. 13 .

In the guard unit 30 shown in FIG. 13 , the expanded thickness of the terrace portion 12 may be limited by the first gaps T1a and T1b between the inner surfaces in the area A1 facing the terrace portion 12 . Accordingly, it is possible to reduce a phenomenon in which the sealing portion 13 is suddenly opened due to excessive expansion of the terrace portion 12 , thereby delaying gas venting of the secondary battery cell 10 .

Next, a modified example of the above-described guard unit 30 will be described with reference to FIGS. 14 to 16 .

The guard unit 40 shown in FIGS. 14 to 16 is configured to include a first area A1 facing at least a portion of the terrace portion 12 to delay the swelling or bursting of the sealing portion 13. have However, the guard unit 40 shown in FIGS. 14 to 16 is different from the embodiment shown in FIGS. 3 to 6 , 10 , 12 and 13 , the area facing the sealing part 13 is not provided. The difference is that it doesn't.

The guard unit 40 has a shape in which the first interval T1, which is the distance between the inner surfaces of the first area A1, is smaller than the thickness T3 of the cell body member 10a, and through this, the The expansion thickness can be limited. That is, even in the case of the guard unit 40 shown in FIGS. 14 to 16 , it is possible to reduce a phenomenon in which the sealing part 13 is rapidly opened due to excessive expansion of the terrace part 12 , and accordingly, the secondary battery cell 10 ) can delay gas venting

As shown in FIG. 14 , the first interval T1 of the guard unit 40 may have a constant value within the first area A1 . That is, the guard unit 40 may have the same interval T1 at one side 41 and the other side 42 . In this case, it may have a bar shape with a rectangular cross-section.

15 and 16 , the first intervals T1a and T1b of the guard unit 40 may be configured to change within the first area A1. For example, between the distance T1a between the inner surface of the guard member 40 in the portion adjacent to one side 41 of the first area A1 and the inner surface of the guard member 40 in the portion adjacent to the other side 42 . The distance T1b may have different values. 15 , the first intervals T1a and T1b of the guard unit 40 may have a large value in a portion adjacent to the other side 42 far from the cell body member 10a. Alternatively, as shown in FIG. 16 , the first intervals T1a and T1b of the guard unit 40 may have a large value in a portion adjacent to one side 41 close to the cell body member 10a. Although not shown in the drawings, it is also possible that the first interval between the central portions of the one side 41 and the other side 42 has the largest value.

When the first interval (T1a, T1b) of the guard unit 40 is changed, the average value of the first interval is greater than the thickness (T3) of the cell body member (10a) so as to limit the expanded thickness of the terrace portion (12). It can have a small value. Likewise, the maximum value of the first interval may also have a value smaller than the thickness T3 of the cell body member 10a.

On the other hand, the first gap (T1, T1a, T1b) between the inner surfaces in the area A1 facing the terrace portion 12 so that the terrace portion 12 can be introduced into the opening 43 of the guard unit 40 is It may have a value greater than the thickness of the terrace portion 12 .

In addition, the guard unit has a bar shape, and may be disposed between the terrace portion 12 in a state separated from the bus bar member (21 in FIG. 1 ).

In the above, the embodiment of the present invention has been mainly described with respect to the 'battery module', but the 'battery module' according to the embodiment of the present invention is not limited to a typical battery module accommodated in a battery pack. For example, the 'battery module' according to the present invention may include a battery pack having a plurality of secondary battery cells 10 and a battery management system (BMS) inside the housing unit. That is, the 'battery module' according to the present invention may include a cell-to-pack structure in which a plurality of secondary battery cells 10 are directly installed inside a pack housing (housing unit). . In consideration of this point, in the claims, a 'battery module' according to the present invention is defined as including both a battery module in a conventional sense and a battery pack in a conventional sense.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it is understood that various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be obvious to one with ordinary knowledge.

For example, it may be implemented by deleting some components in the above-described embodiment, and each embodiment may be implemented in combination with each other.

10: secondary battery cell 11: electrode lead part
12: terrace part 13: sealing part
20: housing unit 21: bus bar member
22: bottom member 23: cover member
24: side wall member 25: front member
26: rear member 30, 40: guard unit
31: first block member 32: second block member
33: expansion guide member 34: needle member
35: reinforcing pad member 36: holding member

Claims (19)

a plurality of secondary battery cells including an electrode lead part connected to the electrode assembly, a terrace part forming an edge of a cell body member in which the electrode assembly is accommodated, and a sealing part connected to the terrace part;
a housing unit accommodating the plurality of secondary battery cells therein; and
a guard unit including a first area facing at least a portion of the terrace portion to delay swelling or bursting of the sealing portion of the at least one secondary battery cell;
includes,
The guard unit is a battery module having a shape in which a first interval, which is a distance between the inner surfaces of the first region, is smaller than the thickness of the cell body member so as to limit the expansion thickness of the terrace portion. According to claim 1,
The first interval is a battery module having a constant value within the first region. The method of claim 1,
the first interval varies within the first region;
The average value of the first interval is a battery module having a smaller value than the thickness of the cell body member. 4. The method of claim 3,
The maximum value of the first interval is a battery module having a value smaller than the thickness of the cell body member. According to claim 1,
The first interval is a battery module having a larger value than the thickness of the terrace portion. According to claim 1,
a bus bar member to which the electrode lead portions of the plurality of secondary battery cells are electrically connected;
further comprising,
The guard unit has a bar shape, and the battery module is disposed between the terrace part in a state separated from the bus bar member.
According to claim 1,
The guard unit includes the first area and a second area installed to face the sealing part,
The first interval is a battery module that varies within the first area. 8. The method of claim 7,
The minimum value of the first interval is smaller than the second interval or has the same value as the second interval. 8. The method of claim 7,
The average value of the first interval is a battery module having a larger value than the second interval. 8. The method of claim 7,
The guard unit,
a first block member having a slit hole into which the sealing part is inserted; and
a second block member having an opening facing at least a portion of the terrace portion;
includes,
The first region is formed across the opening and the slit hole.
According to claim 1,
The guard unit includes the first area and a second area installed to face the sealing part,
A second interval, which is a distance between inner surfaces of the second region, has a value equal to or greater than the first interval. 12. The method of claim 11,
At least one of the first interval and the second interval has a value that varies within each region,
The average value of the second interval is equal to or greater than the average value of the first interval. 12. The method of claim 11,
The guard unit,
a first block member having a slit hole facing at least a portion of the sealing part;
a second block member having an opening facing at least a portion of the terrace portion; and
an intermediate block member positioned between the first block member and the second block member and having a connection opening for accommodating the sealing portion and the terrace portion together;
A battery module comprising a.
12. The method of claim 7 or 11,
The guard unit includes a plurality of unit units disposed between terraces of adjacent secondary battery cells,
A plurality of the unit units are integrated to form an integrated guard unit battery module. 15. The method of claim 14,
at least one bus bar member in which the integrated guard unit is embedded;
further comprising,
A battery module to which the electrode lead portions of the plurality of secondary battery cells are electrically connected to the bus bar member. 12. The method of claim 7 or 11,
a bus bar member to which the electrode lead portions of the plurality of secondary battery cells are electrically connected;
further comprising,
The guard unit is a battery module disposed between the terrace portion in a state separated from the bus bar member. 12. The method of claim 7 or 11,
a bus bar member to which the electrode lead portions of the plurality of secondary battery cells are electrically connected;
further comprising,
The guard unit is a battery module disposed between the terrace portion in a state coupled to the bus bar member. 12. The method of claim 7 or 11,
The guard unit, based on the longitudinal direction of the cell body member, a battery module having a shape that faces 50% or more of the entire length of the terrace portion and the sealing portion. According to claim 1,
The guard unit is a battery module that is installed to face a portion of the sealing portion where the electrode lead portion is disposed.

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