KR102092852B1 - Battery Pack - Google Patents

Abstract

The battery pack according to an aspect of the present invention, a plurality of battery modules are arranged adjacent to each other with a spaced apart spaced portion therebetween, and two battery modules adjacent to each other across the spaced spaced portion of the plurality of battery modules electrically Interbus bar to be connected and spaced apart, and at least one of the two battery modules is expanded, compressed in the width direction of the spaced apart and extendable in the longitudinal direction of the spaced off to cut the busbar cutting the interbus bar Includes units.

Description

Battery Pack {Battery Pack}

The present invention relates to a battery pack, and more particularly, relates to a battery pack that can promote safety by breaking the interbus bar that electrically connects the battery modules and battery modules adjacent to each other in an emergency.

2. Description of the Related Art Recently, secondary batteries have been widely used in electric vehicles (EVs), hybrid vehicles (HEVs), and electric power storage devices (Energy Storage Systems) driven by electric driving sources as well as portable devices. These secondary batteries are attracting attention as a new energy source for eco-friendliness and energy efficiency enhancement, in that they do not generate any by-products due to the use of energy, as well as a primary advantage that can dramatically reduce the use of fossil fuels.

In particular, a battery pack applied to an electric vehicle or the like 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 (cell) can be repeatedly charged and discharged by electrochemical reaction between components, including a positive electrode and a negative electrode current collector, a separator, an active material, an electrolyte, and the like.

On the other hand, since the multi-module battery pack is manufactured in a form in which a plurality of unit cells are concentrated in a narrow space, it is important to easily dissipate heat generated in each unit cell. Since the process of charging or discharging the unit cell, that is, the secondary battery is performed by an electrochemical reaction as described above, if the heat of the battery module generated in the charging and discharging process is not effectively removed, the internal temperature of the secondary battery rapidly increases. The rapid rise in temperature may cause a decomposition reaction of the electrolyte solution, and gas may be generated.

In this case, a swelling phenomenon, which is a kind of component phenomenon, may occur due to an increase in the pressure inside the battery case. Furthermore, when the swelling phenomenon is intensified, serious problems such as an explosion of the secondary battery may occur.

Thus, when the pressure exceeds the standard, there are proposed methods to discharge the gas inside the battery case to drop the internal pressure, but these methods are applied in units of individual cells, and the configuration is not simple, resulting in poor economic efficiency and productivity. There is this. Therefore, there is a need to research and develop a more effective and simple safety device that can promote the safety of the battery pack.

Therefore, the present invention was devised to solve the above problems, and it is possible to prevent the battery module from reaching an explosion due to overheating and overcharge, and to provide a battery pack equipped with a safety device that is simple to configure and install. The purpose.

According to an aspect of the present invention, a plurality of battery modules arranged adjacent to each other with a spaced apart spaced portion therebetween; An interbus bar for electrically connecting two battery modules adjacent to each other across the space portion among the plurality of battery modules; And a bus bar which is disposed in the spaced part, and when at least one of the two battery modules expands, is compressed in a width direction of the spaced part and extendable in a lengthwise direction of the spaced part. A battery pack including a cutting unit can be provided.

The bus bar cutting unit, a deformed foam provided in a balloon structure; And it may include a cutting bar coupled to one side of the deformed foam so that the end is facing the inter bus bar.

The deformable foam may have a truncated cylindrical shape with a convex center portion.

The cutting bar may be mounted on the truncated surface of the deformation foam.

According to another aspect of the present invention, the bus bar cutting unit may be provided with an elastically deformable material and have a tip in a direction toward the inter bus bar.

A cutter may be further mounted on the tip.

In the inter bus bar, a notch may be formed in the body.

According to another aspect of the present invention, the bus bar cutting unit includes a cylinder that accommodates a working fluid in an interior space, and a cutting bar that is directed toward the inter bus bar and is capable of translating relative to the cylinder by the working fluid. Cylinder module provided; And a plunger module that protrudes from the wall surfaces of the two battery modules facing each other in the width direction of the spaced part and is configured to connect an end portion to the inside of the cylinder to pressurize the working fluid when the battery module is expanded. can do.

The plunger module, a flange attached to the wall surface of the battery module; It may include a telescopic portion extending in the width direction of the spaced portion in a bellows form from the center of the flange, and a pressing portion extending from the telescopic portion to the inside of the cylinder module.

The cylinder may be provided in the form of a "T" shaped tubular body.

The bus bar cutting unit may further include an electrically insulating insulating material on an outer peripheral portion.

According to another aspect of the present invention, an automobile including the above-described battery pack can be provided.

According to an aspect of the present invention, by providing a bus bar cutting unit, it is possible to prevent explosion of the battery modules by breaking the electrical connection between the battery modules in an emergency.

According to another aspect of the present invention, since the busbar cutting unit is operated by a mechanism using the expansion pressure of the battery module, it is efficient, and the structure is simple, so it may be economical because there is no need to significantly change the design of the existing battery pack.

1 is a side view schematically showing a configuration of a battery pack according to an embodiment of the present invention.
FIG. 2 is a top view of the battery pack of FIG. 1.
3 is a schematic perspective view of a bus bar cutting unit according to an embodiment of the present invention.
4 and 5 are views schematically showing a state change of the bus bar cutting unit according to an embodiment of the present invention.
6 is a diagram showing modifications of the inter bus bar of the present invention.
7 and 8 are views schematically showing a state change of the bus bar cutting unit according to another embodiment of the present invention.
9 and 10 are views schematically showing a state change of the bus bar cutting unit according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or lexical meanings, and the inventor appropriately explains the concept of terms to explain his or her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

In addition, in the description of the present invention, when it is determined that detailed descriptions of related well-known structures or functions may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

Since the embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art, the shapes and sizes 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 side view schematically showing a configuration of a battery pack according to an embodiment of the present invention, and FIG. 2 is a top view of the battery pack of FIG. 1.

First, a schematic configuration of the battery pack 1 of the present invention will be briefly described with reference to FIGS. 1 and 2.

Referring to these drawings, the battery pack 1 according to an embodiment of the present invention includes a plurality of battery modules 10a and 10b, an inter bus bar 20 and a bus bar cutting unit 30. The battery pack 1 may be configured such that a plurality of battery modules 10a and 10b are connected in series or in parallel with each other according to the use purpose. Each of the plurality of battery modules 10a and 10b may include a battery cell 11, a cell cover 12 and a cooling tube (not shown).

The battery cell 11 may be preferably a pouch-shaped battery cell 11 to provide a high stacking rate in a limited space. The pouch-type battery cell 11 includes an electrode assembly composed of a positive electrode plate, a separator, and a negative electrode plate, and positive and negative leads are electrically connected to a plurality of positive and negative tabs protruding from the positive and negative plates of each battery cell 11, respectively. It may be connected to. In addition, the pouch-type battery cell 11 may have a structure in which an edge assembly of the exterior case is heat-sealed and sealed in a state in which an electrode assembly is embedded in an exterior case of a laminate sheet including a resin layer and a metal layer.

The cell cover 12 is a configuration used to stack the battery cells 11, and is configured to hold the battery cells 11 to prevent their flow and to be stackable to guide the assembly of the battery cells 11 Can play a role.

The cooling tube is provided in the form of a tube having a hollow structure through which a refrigerant flows, and may be interposed between each battery cell 11 or cell cover 12. The battery pack 1 may further include a cooling water supply duct 13, and the cooling tube may be configured to be connected to the cooling water supply duct 13 so that the cooling water circulates therein.

Meanwhile, the plurality of battery modules 10a and 10b may be electrically connected to each other by the inter bus bar 20. 1 and 2, the inter bus bar 20 electrically connects the two battery modules 10a, 10b by having both ends coupled to the external terminals of the two battery modules, respectively. For reference, it is obvious that a high output / high capacity battery pack can be implemented by connecting two or more battery modules 10a and 10b in this manner.

The inter bus bar 20 is a thin plate-shaped or rod-shaped conductor, allowing the flow of a large current between two battery modules 10a and 10b. The inter bus bar 20 may be made of a metal such as copper (Cu), tin (Sn), gold (Au), silver (Ag), and alloys thereof, and may be coated with an electrical insulating material. In addition, the inter bus bar 20 may be bolted or welded to the external terminals of the battery modules 10a and 10b whose both ends are adjacent to each other.

In particular, the battery modules (10a, 10b) of the present invention may be arranged adjacent to each other with a spaced space portion (S) of a predetermined interval. In addition, the inter bus bar 20 may be installed to cross the space S between the battery modules 10a and 10b. For example, as illustrated in FIGS. 1 and 2, external terminals are provided at both upper edge regions of the battery modules 10a and 10b, and two external terminals adjacent to each other are interposed in the two battery modules 10a and 10b. By connecting to the bus bar 20, it can be installed to cross the space between the battery modules (10a, 10b), that is, spaced apart portion (S).

In addition, the inter-bus bar 20 of the present invention may be provided such that at least a part of the spacer space S is less rigid than other parts. For convenience of description, the portion having low rigidity will be referred to as the soft portion 21. For example, the soft portion 21 may have a notch formed in a predetermined depth recessed from the surface of the inter bus bar 20. Notches, as shown in (a) to (c) of Figure 3, at least one of the upper and lower surfaces of the inter bus bar 20 may be inwardly recessed form. 3 (d) is another modified example of the soft portion 21, and the soft portion 21 may be formed of a mesh structure.

By placing the soft part 21 in the inter bus bar 20 in this way, the inter bus bar 20 can be easily broken by an external impact in case of an emergency. Particularly, the soft part 21 may be provided with a notch, so that a rapid fracture effect may be expected due to heat generation due to an increase in electrical resistance when an overcurrent flows.

The bus bar cutting unit 30 serves to cut off the electrical connection between the battery modules 10a and 10b in an emergency. For example, in case of an emergency, the inter bus bar 20 is cut off by the bus bar cutting unit 30 to cut off external power and thus stop charging or discharging of the battery cells 11.

4, the busbar cutting unit 30 of the present invention is disposed in a space S between two battery modules. More specifically, it can be disposed in the space between the battery modules just below the reference to the soft part 21 of the inter bus bar 20.

In addition, the bus bar cutting unit 30 may be configured to cut the inter bus bar 20 by applying an impact to the weak portion 21 of the inter bus bar 20 when the battery module is inflated. In other words, the busbar cutting unit 30 is compressed under pressure from the battery module while the spacer part S is narrowed due to expansion of at least one of the two battery modules, and extends toward the interbus bar 20 It can be configured as possible.

The bus bar cutting unit 30 according to an embodiment of the present invention may include a deformed foam 31 and a cutting bar 32. The deformable foam 31 may be a balloon or a component formed of an elastically deformable material. For example, the deformable foam 31 may be embodied as an air-bag, a spherical soft rubber, or the like, which can be deformed even at a slight pressure. Of course, the deformable foam 31 can be made of whatever material is applied as long as it is made of a material that is well stretched and elastic without breaking by pressure. However, the deformable foam 31 is preferably selected from electrically insulating materials.

Deformed foam 31, as shown in Figure 4, may be a truncated cylindrical shape with a convex center portion. As such, when the middle portion is convexly swelled compared to the upper and lower portions, extensibility in the upper and lower directions during compression may be higher.

The cutting bar 32 may be configured with a mounting plate 32a forming a lower end of the cutting bar 32 and a bar 32b having a sharp end. The mounting plate 32a has a flat plate surface and can be stably coupled to the truncated surface 31a of the deformed foam 31 by making surface contact with the truncated surface 31a of the deformed foam 31. For example, one surface of the mounting plate 32a and the truncated surface 31a of the deformable foam 31 may be configured to be bonded to each other. The bar 32b may have a body extended by a predetermined length and a sharp end.

The cutting bar 32 is preferably excellent in electrical insulation, and may be made of a material having higher rigidity than the inter bus bar 20. For example, tempered glass, tempered plastic, ceramics, and the like may be used, but are not limited thereto. For example, the cutting bar 32 may be a stainless steel coated with an electrically insulating insulating material.

Hereinafter, the operation of the bus bar cutting unit 30 according to the present embodiment will be described with reference to FIGS. 5 and 6.

As shown in FIG. 5, the deformable foam 31 is interposed in a state in a circular shape in the space S between the battery modules 10a and 10b, wherein the cutting bar 32 has an end of the interbus bar. It is located opposite to the lower surface of the soft part 21 of (20).

Although not shown in detail, the battery modules 10a and 10b start to expand when the battery cells 11 gradually swell due to a malfunction, overcharge, or overheating of the BMS. For example, the battery module expands in the direction in which the battery cells 11 are stacked, that is, in the same direction as the arrow shown in FIG. 6. Therefore, if at least one of the two battery modules 10a and 10b is expanded, the spaced apart space S becomes narrow and the deformed foam 31 is compressed (in the X-axis direction of FIG. 6), and simultaneously (FIG. 6). (In the Y-axis direction). At this time, with the elongation of the deformable foam 31, the cutting bar 32 is gradually pushed up toward the soft part 21 of the inter bus bar 20.

And at least before the battery module (10a, 10b) reaches the expansion limit value, the cutting bar 32 penetrates the interbus bar 20 and rises upwards, thereby completely breaking the soft portion 21 of the interbus bar 20, thereby removing the battery module. Cut off electrical connections between them. Accordingly, the battery cells 11, which are powered off, are no longer charged or discharged, so that the explosion of the battery module can be prevented.

Here, the expansion limit value of the battery modules 10a and 10b may mean the volume of the battery modules 10a and 10b, which are starting to increase in the possibility that the battery modules 10a and 10b will explode. Accordingly, the space between the battery modules 10a and 10b, that is, the width of the spaced portion S and the deformable foam 31 may be appropriately designed in consideration of the expansion limit value of the battery modules 10a and 10b.

Next, with reference to FIGS. 7 and 8, a modified example of the busbar cutting unit according to the present embodiment will be described.

7 and 8 are views schematically showing a state change of the bus bar cutting unit according to the modification of FIG. 4.

The bus bar cutting unit 30 of FIG. 4 is composed of a deformable foam 31 and a cutting bar 32, whereas the bus bar cutting unit 40 according to the present modified example has a tip 42. It may be an elastically deformed workpiece 41 formed.

For example, as shown in FIG. 7, the bus bar cutting unit 40 of the present modification is formed of a soft rubber of a spherical shape, and may have a tip 42 protruding sharply from the curved surface of the soft rubber. . In addition, the bus bar cutting unit 30 may be interposed in the space part S so that the tip 42 faces the inter bus bar 20.

In addition, a pressure plate 43 may be further provided between the bus bar cutting unit 40 and the side portions of the battery modules 10a and 10b. One surface of the pressure plate 43 is coupled to the wall surface of the battery modules 10a and 10b, and the other surface can support the spherical busbar cutting unit 30. The pressure plate 43 may be provided in a plate shape to prevent the flow of the spherical busbar cutting unit 30 and to serve to effectively transmit pressure to the busbar cutting unit 30 when the battery module is inflated.

In addition, the cutting edge with respect to the inter-bus bar 20 may be increased by further mounting a cutter having a higher rigidity than the inter-bus bar 20.

The busbar cutting unit 30 according to the present modification has a simple structure compared to the above-described embodiment, and thus has an advantage of easier processing, and is made of a spherical shape, so that the compression rate of the battery modules when inflated compared to the above-described embodiment Contrast elongation may be high. In addition, the bus bar cutting unit 40 according to the present modification can increase the space utilization by using the remaining empty space as a cooling air flow space, etc., because the occupied area is relatively small in the space S.

Another embodiment of the present invention to be described below can be referred to as a configuration corresponding to FIGS. 5 to 6 when compared with the above-described embodiment. The same member number indicates the same member, and duplicate description of the same member will be omitted.

In another embodiment of the present invention, when compared with the above-described embodiment, the busbar cutting unit 50 is compressed in the width direction of the spacer space S by the compression force of the battery modules 10a, 10b and the spacer space ( S) is configured to be stretched in the longitudinal direction is similar, but there is a difference in configuration and operation mechanism. Hereinafter, the differences from the above-described embodiment will be mainly described.

9 and 10 are views schematically showing a state change of the bus bar cutting unit according to another embodiment of the present invention.

Referring to these drawings, the bus bar cutting unit 50 according to another embodiment of the present invention includes a cylinder module 51 and a plunger module 52.

The cylinder module 51 faces the cylinder 51a and the interbus bar 20 that accommodate the working fluid O in the inner space, and is provided with a cutting fluid that is translatable with respect to the cylinder 51a by the working fluid O. And a bar 51b.

For example, as shown in FIG. 9, the cylinder 51a is a "T" shaped tubular body having both openings in the horizontal direction, and the vertical direction has a through hole formed smaller than the diameter.

The cutting bar 51b is located inside the cylinder 51a and is formed integrally with the lower end and the lower end having a shape corresponding to the inner diameter of the cylinder and extends out of the cylinder 51a through the through hole of the cylinder 51a ( bar). And the end of the cutting bar (51b) has a sharp shape. The cutting bar 51b may be extended toward the interbus bar 20 by pushing up the lower end portion by hydraulic pressure or pneumatic pressure of the working fluid O. Here, the working fluid O may be pressurized by the plunger module 52. The working fluid (O) may be a liquid or gas.

The plunger module 52 is configured to press the working fluid O when the battery modules 10a and 10b are expanded, and the spacer portions (on the wall surfaces of the two battery modules 10a and 10b facing each other) It protrudes in the width direction of S) and is configured to be connected to the end portion inside the cylinder 51a.

The plunger module 52 includes a flange 52a coupled to the wall surfaces of the battery modules 10a and 10b, an expansion and contraction portion 52b, and a pressing portion 52c.

The expansion and contraction portion 52b extends in the width direction of the separation space portion S at the center of the flange 52a and may be formed of a bellows-type or compressible material. And the pressing portion 52c is connected to the expansion and contraction portion 52b, extends to the inside of the cylinder 51a, and may be made of a hard rubber material. Here, referring to FIG. 10, the expansion and contraction part 52b may be provided to contract in the same direction as the expansion direction of the battery modules 10a and 10b when at least one of the two battery modules 10a and 10b is expanded. .

The expansion and contraction portion 52b has a predetermined flexibility in a bellows shape, and may serve to alleviate the impact of the cylinder 51a upon irregular expansion of the battery modules 10a and 10b. However, if only the portion of the expansion and contraction portion 52b is excessively compressed, the pressing force of the pressing portion 52c that pushes up the working fluid O may drop, so that the expansion and contraction portion 52b has flexibility but has a predetermined mechanical support force. It may be provided with a metal material or a hard rubber.

 The pressing portion 52c is a portion that is slidingly coupled to the inside of the cylinder 51a through the opening of the cylinder 51a and moves in the width direction of the separation space portion S when the battery modules 10a and 10b expand. O) serves to pressurize.

For example, when the battery module is inflated in the direction of the arrow in FIG. 10, the pressing portion 52c of the plunger module 52 is in the width direction (the X-axis direction) of the spacer unit S due to the pressure of the battery modules 10a and 10b. ) While pressing the working fluid (O) inside the cylinder. The pressurized working fluid (O) increases in the longitudinal direction (Y-axis direction) of the spacer part (S) while simultaneously extending the cutting bar (51b).

When the battery modules 10a and 10b reach the expansion limit value in this way, the battery modules 10a and 10b are configured by cutting the soft part 21 of the inter bus bar 20 completely by the cutting bar 51b. It can cut off the electrical connection between them.

As described above, the battery pack 1 according to an aspect of the present invention is provided with a bus bar cutting unit (30, 40, 50) to cut off the electrical connection between the battery modules (10a, 10b) in an emergency and the battery module ( 10a, 10b) explosion can be prevented. In particular, the bus bar cutting unit (30, 40, 50) of the present invention is mechanically operated by the expansion pressure of the battery modules (10a, 10b), so it is efficient and simple in structure and economical. In addition, even in the application of the bus bar cutting units 30, 40 and 50, there is an advantage that there is no need to significantly change the design of the existing battery pack 1.

Meanwhile, the battery pack 1 according to the present invention can be applied to an automobile 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.

The preferred embodiments of the present invention have been shown and described above, but the present invention is not limited to the specific preferred embodiments described above, and the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Of course, various modifications can be made to anyone having ordinary knowledge, and such changes are within the scope of the claims.

Meanwhile, in this specification. Terms indicating directions such as up, down, left, and right are used, but these terms are merely for convenience of explanation, and can be expressed differently according to the viewing position of the observer or the position of the object. Is self-evident.

1: Battery pack 10a, 10b: Battery module
11: Battery cell 12: Cell cover
13: Cooling water supply duct 20: Inter bus bar
21: weak part 30,40,50: bus bar cutting unit
31: Deformed foam 32: Cutting bar
41: elastic deformation workpiece 42: tip
51: cylinder module 51a: cylinder
52: plunger module 52a: flange
52b: telescopic portion 52c: pressing portion
S: Spaced apart

Claims (12)

A plurality of battery modules arranged adjacent to each other with a spaced apart portion at a predetermined interval therebetween;
An interbus bar for electrically connecting two battery modules adjacent to each other across the space portion among the plurality of battery modules; And
The bus bar is disposed in the spaced part, and when at least one of the two battery modules is inflated, compressed in the width direction of the spaced part and extendable in the length direction of the spaced part to cut the inter bus bar. Includes units,
The surface of the inter bus bar is formed with a soft portion made of a mesh structure,
The bus bar cutting unit,
A cylinder module having a cylinder accommodating a working fluid in an inner space, and a cutting bar facing the soft part of the interbus bar and being provided in a translational motion with respect to the cylinder by the working fluid; And
And a plunger module configured to protrude in the width direction of the spaced part from the wall surfaces of the two battery modules facing each other and to be connected to the inside of the cylinder at an end portion to pressurize the working fluid when the battery module is expanded. ,
The plunger module,
A flange attached to the wall surface of the battery module;
A stretchable part extending in the width direction of the spaced part in a bellows form from the center of the flange and having flexibility; And
It includes a pressing portion extending from the expansion portion to the interior of the cylinder module,
The expansion and contraction of the battery pack, characterized in that when the expansion of at least one of the two battery modules in the same direction as the expansion direction of the battery module. delete delete delete delete delete delete delete delete According to claim 1,
The cylinder, the battery pack, characterized in that provided in the form of a "T" shaped tubular body. According to claim 1,
The bus bar cutting unit, the battery pack characterized in that it further comprises an electrically insulating insulating material on the outer periphery. A vehicle comprising the battery pack according to any one of claims 1 and 10 to 11.

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