KR102148497B1 - Battery Pack - Google Patents

Abstract

In the battery pack according to an aspect of the present invention, a battery module assembly comprising one or more battery modules electrically connected to each other, leaving an empty space between an inner wall surface of an end plate supporting an outer side of the battery module assembly and the end plate, A pack case accommodating a battery module assembly, and a damping unit coupled to at least one of an inner wall surface of the pack case and the end plate, disposed in the empty space, and compressible by an external load.

Description

Battery Pack {Battery Pack}

The present invention relates to a battery pack, and more particularly, to a battery pack capable of safely protecting a battery module from external shock and vibration.

Recently, rechargeable batteries have been widely applied to portable devices as well as electric vehicles (EVs), hybrid electric vehicles (HEVs), and energy storage systems driven by an electric drive source. Such a secondary battery is attracting attention as a new energy source for environmentally friendly and energy efficiency improvement in that it does not generate by-products from the use of energy as well as the primary advantage that it can dramatically reduce the use of fossil fuels.

Particularly, a battery pack applied to an electric vehicle has a structure in which a plurality of battery modules including a plurality of unit cells are connected in series and/or in parallel to obtain high output. Here, the unit cell may be repeatedly charged and discharged by an electrochemical reaction between constituent elements including a positive electrode and a negative electrode current collector, a separator, an active material, an electrolyte, and the like.

Meanwhile, when the battery pack is mounted on a vehicle as a driving source, the battery pack may be continuously exposed to shock and vibration environments. In particular, in the event of an accident such as a car crash or rollover, an impact may be applied to the battery pack inside the vehicle. In this case, the battery module may be severely damaged or ignite, and the accident may spread to a secondary level.

As a countermeasure against this, the conventional battery pack protects the battery module from external shocks with an end plate and a pack case made of a rigid material. The end plate is made of a metal material and is mounted on the outer surface of the battery module to provide mechanical support for the battery module. In addition, the battery module may be accommodated in a pack case made of a rigid material.

However, there is a limit to the absorption of external shock and vibration by only the existing pack case and end plate. For example, in the event of a vehicle collision, the battery pack case and the end plate may be deformed without withstanding an external load, and thus battery modules may be directly damaged. Therefore, there is a need for a way to protect the battery module even in a strong impact such as a vehicle collision.

The present invention is invented in consideration of the above-described problems, and provides a battery pack capable of protecting an internal battery module when a battery pack is compressed due to a vehicle collision or the like.

According to an aspect of the present invention, a battery module assembly configured by electrically connecting one or more battery modules; An end plate supporting an outside of the battery module assembly; A pack case for accommodating the battery module assembly while leaving an empty space between the inner wall surface and the end plate; And a damping unit coupled to at least one of the inner wall surface of the pack case and the end plate and disposed in the empty space, and provided to be compressible by an external load.

The damping unit may include a hollow structure having both ends coupled between an inner wall surface of the pack case and the end plate, and the hollow structure may include a corrugated pipe portion in which at least one section is formed in a bellows shape.

The hollow structure may further include a concave pipe portion formed in a shape that is continuously constricted to the corrugated pipe portion and a support pipe portion formed in a smooth column shape with the corrugated pipe portion provided to a predetermined section based on the inner wall surface of the pack case. have.

The damping unit may further include an elastic body provided inside the hollow structure.

The hollow structure may be formed of a material having lower rigidity than that of the battery pack case and the end plate and having excellent ductility that is not broken by external impact.

The hollow structure may be provided with at least one of polypropylene resin, polystyrene resin, and polyethylene resin.

According to another aspect of the present invention, the damping unit may include a damper member coupled to the end plate in a cantilever shape such that the free end on which the elastic body is mounted faces the inner wall surface of the pack case.

The damping unit may further include an elastic body cover member having a receiving groove formed so that the elastic body can be inserted, and coupled to an inner wall surface of the pack case so that the receiving groove faces the elastic body.

A plurality of damping units may be disposed in the empty space and spaced apart from each other by a predetermined interval.

According to another aspect of the present invention, the damping unit may be a cushion pad containing at least one of high elastic sponge, polyurethane foam, latex foam, and air.

The cushion pad may be formed in an oval or spherical shape.

The cushion pads may include a plurality of unit cushion pads covering the entire surface of the end plate by being closely disposed in contact with each other.

According to another aspect of the present invention, a vehicle including the above-described battery pack may be provided.

According to an aspect of the present invention, even if the battery pack case is compressed due to a vehicle collision or the like, the damping unit absorbs the shock, thereby protecting the internal battery modules.

1 is a perspective view schematically showing the configuration of a battery pack according to a first embodiment of the present invention.
2 is a structural diagram showing a buffering action of the damping unit according to the first embodiment of the present invention.
3 is a structural diagram showing a modified example of the damping unit of FIG. 2.
4 is a structural diagram showing another modified example of the damping unit of FIG. 2.
5 is a structural diagram showing the buffering action of the damping unit according to the second embodiment of the present invention.
6 is a structural diagram showing the buffering action of the damping unit according to the third embodiment of the present invention.
7 is a structural diagram showing a modified example of the damping unit of FIG. 6.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Since the embodiments of the present invention are provided to more completely describe the present invention to a person skilled in the art, the shape and size of components in the drawings may be exaggerated, omitted, or schematically illustrated for a more clear description. Therefore, the size or ratio of each component does not entirely reflect the actual size or ratio.

1 is a perspective view schematically showing the configuration of a battery pack according to a first embodiment of the present invention.

Referring to FIG. 1, a battery pack 1 according to a first embodiment of the present invention includes a battery module assembly 10, an end plate 20, a pack case 30, and a damping unit 40.

The battery pack 1 may be configured such that a plurality of battery modules 11 are connected in series or parallel to each other according to the intended use. Although not shown in detail for convenience of drawing, each of the battery modules 11 may be configured as a cell assembly in which a plurality of battery cells are stacked.

Here, the battery cell may preferably be a pouch-type battery cell to provide a high stacking rate in a limited space, but may be a rectangular or cylindrical battery cell.

The pouch-type battery cell includes an electrode assembly composed of a positive plate, a separator, and a negative plate, and a positive lead and a negative lead are electrically connected to a plurality of positive and negative tabs protruding from the positive and negative plates of each battery cell. . In addition, the pouch-type battery cell may have a structure in which an edge portion of the outer case is heat-sealed and sealed in a state in which the electrode assembly is embedded in an outer case of a laminate sheet including a resin layer and a metal layer.

In addition, the battery module 11 may further include a cartridge configured to hold the pouch-type battery cells to prevent their flow and to be stackable. Here, the cartridge may be referred to by other terms such as a cell cover or a stacking frame.

The plurality of battery modules 11 may be electrically connected to each other by an inter bus bar 12. Both ends of the inter bus bar 12 are coupled to external terminals of the two battery modules 11 to electrically connect the two battery modules 11. By connecting the plurality of battery modules 11 in this manner, a high output/high capacity battery module assembly 10 may be configured.

The end plate 20 may be a plate-shaped structure and may be disposed on the outer surface of the battery module assembly 10. The end plate 20 may be configured in a plate shape having an approximately large area, and may cover an outer portion of the battery module assembly 10.

Illustratively, the end plate 20 of FIG. 1 is disposed one by one on the left and right sides of the battery module assembly 10, but the end plate 20 is further disposed above and below the battery module assembly 10 or , It may be disposed to surround the entire battery module assembly 10. In addition, the end plate 20 may be configured to be installed on each of the battery modules 11.

The end plate 20 may serve to provide mechanical support for the battery module 11 to the battery module assembly 10 and to protect the battery module 11 from external shocks. Therefore, the end plate 20 may be made of a metal material such as steel to ensure rigidity.

The pack case 30 accommodates the battery module assembly 10 and the end plate 20 described above in a box shape. Although not shown in FIG. 1, in addition to the battery module 11, various devices for controlling charge and discharge of the battery module 11, such as BMS, current/voltage sensor, fuse, etc., may be further included in the pack case 30. have.

Although the pack case 30 of this embodiment has a substantially rectangular parallelepiped shape, it is obvious that the shape of the pack case 30 can be changed in any number to suit the location of use. The pack case 30 may be made of steel or reinforced plastic material to maintain rigidity, and may have a substantially sealed structure. In addition, the pack case 30 may further include a venting port 13 for discharging external gas to the outside of the vehicle through a specific path when an event occurs due to overheating or overcharging of the battery cell.

On the other hand, the battery module assembly 10 of the present invention is seated inside the pack case 30 with a predetermined empty space S between the inner wall surface 30a of the pack case 30 and the end plate 20. In addition, a damping unit 40 may be disposed in the empty space S.

The damping unit 40 does not cause physical damage to the end plate 20 by using the minimum shrinkage thickness even if the pack case 30 is pushed toward the end plate 20 in response to an external load in case of an accident such as a vehicle collision. It serves to prevent.

As shown in FIG. 1, a plurality of damping units 40 of the present embodiment are disposed on the left and right sides of the battery module assembly 10, respectively. The position of the damping unit 40 may correspond to the front and rear directions of the vehicle when the battery pack 1 is mounted on the vehicle. Of course, since Fig. 1 shows an embodiment of the present invention, the scope of the present invention is not limited thereto. That is, the damping unit 40 may be configured to be radially disposed with respect to the battery module assembly 10.

2 is a structural diagram showing a buffering action of the damping unit according to the first embodiment of the present invention.

Referring to FIG. 2A, the damping unit 40 of this embodiment may be a hollow structure having a corrugated pipe part 41 formed in a bellows shape. In addition, the hollow structure may be made of a material having lower rigidity than the pack case 30 and the end plate 20 and having excellent ductility that is not broken by external impact. For example, the hollow structure may be manufactured by blending any one of polypropylene resin, polystyrene resin, and polyethylene resin, or an additive for improving the properties thereof.

These resins basically have the advantages of excellent electrical insulation, impact resistance, chemical stability, and ease of processing, and particularly have good ductility and can be compressed without being easily broken against external loads. Of course, since the scope of the present invention is not limited to the above-described resins, other synthetic resins or compressible and expandable materials having good ductility and non-breakable physical properties may be used.

In addition, the damping unit 40 of this embodiment is designed to have a hollow structure that is hollow, thereby lowering rigidity and increasing compressibility against external loads. And the hollow structure is provided with a bellows-shaped corrugated pipe part 41 in the longitudinal direction, so that compression can be induced without breaking against external loads, and as the total cross-sectional area that can be compressed is increased, a greater amount of impact Can absorb.

This hollow structure, as shown in Figure 2 (b), by absorbing a significant amount of impact while being compressed by an external load can prevent the pack case 30 from being pushed toward the end plate 20. Therefore, even if a strong external load is applied to the battery pack 1, as in a vehicle crash accident, at least the hollow structure suppresses the pack case 30 from being pushed in and deforming the end plate 20 so that the battery modules 11 May not be damaged.

FIG. 3 is a structural diagram illustrating a modified example of the damping unit of FIG. 2, and FIG. 4 is a structural diagram illustrating another modified example of the damping unit of FIG. 2. Next, modified examples of the present embodiment will be described with reference to these drawings.

First, as shown in (a) of FIG. 3, the damping unit 40' of this modified example includes a corrugated pipe part 41 formed only up to a predetermined section extending from the inner wall surface 30a of the pack case 30, and , It includes a concave pipe portion 42 formed in a concave shape in the middle section of the hollow structure, and a support pipe portion 43 formed in a smooth column shape from the concave pipe portion 42 to the end plate 20. That is, the hollow structure of the present modified example, compared to the hollow structure of Figure 2, the corrugated pipe portion 41 is formed only in a certain section, in succession with the corrugated pipe portion 41, the concave pipe portion 42 and the support pipe portion 43 There is a difference that it is equipped.

As described above, according to the present modified example, when an external load is applied, the shock absorbing power and support of the damping unit 40 ′ to the pack case 30 may be higher.

To further explain, the hollow structure absorbs impact while the corrugated pipe part 41 is first compressed by an external load. However, in general, the range and location to which the external load is transmitted are irregular. In this case, as shown in (b) of FIG. 3, the hollow structure may be twisted and compressed in the concave pipe portion 42.

As described above, the concave pipe portion 42 is formed in a shape that is recessed in the circumferential direction of the hollow structure. Accordingly, the concave pipe portion 42 may be compressed irregularly by twisting due to geometric characteristics if the direction and magnitude of the force acting per unit area are not uniform. In this way, when the concave pipe portion 42 is twisted and compressed irregularly, the external load cannot be completely concentrated in the axial direction of the hollow structure. Therefore, the concave pipe portion 42 and the continuous support pipe portion 43 can receive less vertical load.

The support pipe part 43 serves to provide mechanical support for the pack case 30 pushed in by an external load. In particular, the support pipe portion 43 of the present modified example may have higher structural rigidity than the corrugated pipe portion 41 even though it is a non-breakable ductile material, so that the impact resistance against an external load may be higher. Since the support pipe part 43 not only has a predetermined mechanical support, but also receives a vertical load distributed by the concave pipe part 42, the pack case 30 may more effectively prevent the push in.

Subsequently, the damping unit 40 ″ of another modified example illustrated in FIG. 4 is made of a hollow structure having a bellows-shaped corrugated pipe part 41, like the damping unit 40 illustrated in FIG. 2. The difference between the damping unit 40 ″ of this modified example and the damping unit 40 of FIG. 2 is that an elastic body is further provided inside the hollow structure. Here, the elastic body may be the coil spring 44, but it is not necessarily limited thereto, and may be any one having an elastic deformation force.

The damping unit 40 ″ of this modified example has the advantage that the compressive force of the hollow structure and the compressive force of the elastic body may be added, so that the shock absorption rate for external loads may be higher. In addition, since the elastic body is located in the empty space (S) inside the hollow structure, space utilization may be increased.

Hereinafter, a damping unit according to other embodiments of the present invention will be described.

5 is a structural diagram showing a buffering action of the damping unit 50 according to the second embodiment of the present invention. The same reference numerals denote the same members, and redundant descriptions of the same members are omitted, and differences from the above-described embodiments will be mainly described.

The damping unit 50 according to the second embodiment of the present invention includes a damper member 51 and an elastic cover member 53.

The damper member 51 may be coupled to the end plate 20 in a cantilever shape. An elastic body 52 is mounted at the free end of the damper member 51 and faces the inner wall surface 30a of the pack case 30. The elastic cover member 53 may be coupled to the inner wall surface 30a of the pack case 30 so as to face the damper member 51. In addition, the elastic cover member 53 has a receiving groove in the axial direction, and is provided so that the damper member 51 can be inserted into the receiving groove. A plurality of such damping units 40 ″ may be disposed in the empty space S of the pack case 30 at a predetermined distance from each other.

For example, as shown in (a) of FIG. 5, each of the plurality of damper members 51 is coupled to the end plate 20 in a cantilever shape, and each of the plurality of elastic body cover members 53 complementary thereto is accommodated. The groove is coupled to the inner wall surface (30a) of the pack case (30) toward the elastic body (52). And, as shown in (b) of Figure 5, even if the pack case 30 is pushed by an external load, the elastic body 52 of the damper member 51 is compressed and absorbs the shock so that the battery modules 11 are protected. Can

The damping unit 50 of the present embodiment has the advantage that the elastic body 52 having a shock absorbing function, for example, a coil spring, can be protected by the elastic body cover member 53 and can be compressed guided. In particular, the damper member 51 and the cover member 53 provide mechanical support for the pack case 30 so that the pack case 30 does not push toward the end plate 20 by a predetermined distance or more. Here, the damper member 51 and the cover member 53 may be preferably made of a metal material such as steel so as to provide strong mechanical support.

6 is a structural diagram showing a buffering action of a damping unit according to a third embodiment of the present invention, and FIG. 7 is a structural diagram showing a modified example of the damping unit of FIG. 6.

Next, referring to Figure 6 (a), the damping unit 60 according to the third embodiment of the present invention, a cushion pad made of at least one of a high elastic sponge, polyurethane foam, latex foam, and air ( 60).

However, the above-mentioned materials are illustrative of the preferred internal structure of the cushion pad 60 according to the present embodiment, and the scope of the present invention is not necessarily limited to the above-mentioned materials. That is, the elastic deformation may be replaced with other materials having lower strength and good ductility than the pack case 30 and the end plate 20.

The cushion pad 60 shown in FIG. 6 has one side attached to the wall surface of the end plate 20 and is separated from the inner wall surface 30a of the pack case 30, but unlike this, the end plate 20 and the pack case 30 It may be configured to completely fill the empty space S between the inner wall surfaces 30a.

For example, the cushion pad 60 may be provided in an oval or spherical shape. According to this configuration, as shown in (b) of FIG. 6, when the pack case 30 is pushed inward by an external load, the cushion pad is compressed in the X-axis direction to which pressure is applied and at the same time, the cushion pad is further compressed in the Y-axis direction. It can be stretched effectively. That is, the elliptical or spherical cushion pad can cover the entire end plate 20 on a wide surface while absorbing the impact caused by an external load, so that the battery module 11 can be effectively protected in a wider range.

Next, a modified example of the damping unit of FIG. 6 will be described with reference to FIG. 7.

While the cushion pad 60 of FIG. 6 is one per side of the end plate 20, the cushion pads 60' of FIG. 7 are densely disposed in contact with each other, so that a plurality of unit cushions covering the entire surface of the end plate 20 It includes a pad 60'a.

The unit cushion pad 60'a, like the cushion pad 60 of FIG. 6, may be made of or enclosed in any one of coelastic sponge, polyurethane foam, latex foam, and air. In addition, in this modified example, the diameter of the unit cushion pad 60'a is smaller than that of the cushion pad 60 of the third embodiment, and the inner wall surface 30a and the end plate 20 of the pack case 30 ) The width of the empty space (S) can be configured to be small.

With this configuration, it is possible to increase the cross-sectional area for absorbing shocks against external loads, and by suppressing the deformation of the end plate 20, damage to the battery modules 11 inside the end plate 20 can be prevented. In addition, since the present modified example can reduce the volume of the empty space S occupied by the damping unit 40, there is an advantage of increasing the capacity of the battery module 11 by that amount.

The battery pack 1 having a damping unit according to the present invention can be applied to a vehicle such as an electric vehicle or a hybrid vehicle. That is, the vehicle according to the present invention may include the battery pack 1 described above.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific preferred embodiments described above, and in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Anyone of ordinary skill in the art can implement various modifications, as well as such modifications will be within the scope of the claims.

On the other hand, in this specification. Although terms indicating directions such as up, down, left, right, etc. were used, these terms are for convenience of explanation only, and it is understood that these terms may be expressed differently depending on the viewing position of the observer or the position of the object. Self-explanatory to

10: battery module assembly 20: end plate
30: pack case 40,50,60: damping unit
41: corrugated pipe part 42: concave pipe part
43: support pipe portion 44: spring
51: damper member 52: elastic body
53: cover member S: empty space

Claims (13)

A battery module assembly 10 configured by electrically connecting one or more battery modules;
An end plate 20 supporting the outside of the battery module assembly;
A pack case 30 for accommodating the battery module assembly while leaving an empty space between the inner wall surface and the end plate; And
Includes a damping unit 40 ′ coupled to at least one of the inner wall surface 30a and the end plate 20 of the pack case and disposed in the empty space, and provided to be compressible by an external load,
The damping unit 40 ′,
A bellows-shaped corrugated pipe part 41 which is formed of a soft material and is a hollow structure that extends from the inner wall surface 30a of the pack case to a predetermined section; A concave pipe portion 42 formed in a concave shape continuously in the corrugated pipe portion; and a support pipe portion 43 formed in a smooth column shape extending from the concave pipe portion to the end plate; And a coil spring-shaped elastic body (44) provided inside the hollow structure, and a plurality of radially disposed inside the pack case around the battery module assembly (10).
delete delete delete The method of claim 1,
The hollow structure is a battery pack, characterized in that provided with a material having a lower rigidity than that of the battery pack case and the end plate and having excellent ductility that is not broken by external impact. The method of claim 1,
The hollow structure is a battery pack, characterized in that provided with at least one of polypropylene resin, polystyrene resin, and polyethylene resin. The method of claim 1,
The damping unit,
The battery pack, characterized in that coupled to the end plate so that the elastic body faces the inner wall surface of the pack case. delete The method of claim 1,
The damping unit is a battery pack, characterized in that the plurality of the plurality of the damping units are spaced apart from each other by a predetermined interval. delete delete delete A vehicle comprising the battery pack according to any one of claims 1, 5 to 7, and 9.

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