KR20210011690A - Battery Module Having Current Breaking Function AND Device Including The Same - Google Patents

Abstract

The present invention relates to a battery module having a current breaking function and a device including the same. The battery module comprises: at least one battery cell including a positive lead and a negative lead; a bus bar formed with at least one slit and connected with the positive lead and the negative lead; a bus bar frame to support the bus bar; and a current breaking member to cut at least one of the positive lead and the negative lead. The current breaking member includes a lead cutter, an elastic body, and a bar-shaped stopper, and thereby moves in the positive lead and/or negative lead when a temperature is increased greater than a predetermined temperature to cut the positive lead and the negative lead.

Description

Battery Module Having Current Breaking Function AND Device Including The Same}

The present invention relates to a battery module equipped with a current blocking function and a device including the same, and more particularly, while maintaining the volume of the battery module as it is, cutting an electrode lead using a volume change of a shape memory alloy during abnormal operation, Ultimately, it relates to a battery module equipped with a current blocking function capable of preventing accidents such as explosion of the battery module in advance, and a device including the same.

As technology development and demand for mobile devices such as mobile phones, laptops, camcorders, and digital cameras increase, technologies for rechargeable and dischargeable secondary batteries are becoming more active. In addition, secondary batteries are applied to electric vehicles (EV), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (P-HEV), as an alternative energy source for fossil fuels that cause air pollutants. The need for development is increasing.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries, among which lithium secondary batteries have little memory effect compared to nickel-based secondary batteries, so charging and discharging are free. , The self-discharge rate is very low and the energy density is high.

These lithium secondary batteries mainly use a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively, and a positive electrode plate and a negative electrode plate coated with a positive electrode active material and a negative electrode active material, respectively, are disposed with a separator interposed therebetween, and an electrode assembly It includes an exterior material that is sealed and accommodated together with an electrolyte solution, that is, a battery case.

Depending on the shape of the battery case, secondary batteries can be classified into cylindrical and prismatic batteries in which the electrode assembly is embedded in a cylindrical or rectangular metal can, and pouch-type batteries in which the electrode assembly is embedded in a pouch-shaped case of an aluminum laminate sheet. I can.

In secondary batteries used in small devices, several battery cells are arranged, but a battery module in which a plurality of battery cells are electrically connected is used in automobiles. In such a battery module, a plurality of battery cells are connected in series and parallel to each other to improve capacity and output. In this case, the battery module includes a plurality of secondary batteries, that is, battery cells are stacked and a bus bar for electrical connection between these battery cells. It is common to include a Busbar module. The bus bar module includes a bus bar for connecting electrode leads connected to each battery cell, and may be formed on one side of the battery module.

On the other hand, when a large current flows within a short period of time due to exposure to high temperatures, overcharging, external short-circuit, bed penetration, and local damage, there is a risk of explosion as the battery is heated by heat generation.

In this regard, Patent Document 1 discloses a plurality of battery modules having external terminals, a power connection bus bar connecting between external terminals provided in each of the adjacent battery modules, and the upper left and lower right of the power connection bus bar. It is connected to the external terminal together with the power connection busbar so that the ends are in close contact with each other at regular intervals, and the center of the power connection busbar is broken by alternating shape deformation at a temperature above the reference temperature made of shape memory alloy. Disclosed is a battery pack including a pair of left and right bus bars for power off.

According to the patent document 1, there is an advantage in that the bus bar for power connection can be broken by using a shape-memory alloy that causes shape change when the temperature rises due to overcurrent, and as a result, thermal runaway can be prevented. Since a large amount of memory alloy is required, and additionally, a flat-shaped power cut-off bus bar must be additionally mounted, the problem that the volume of the battery pack is inevitably increased accordingly remains.

Korean Patent Publication No. 2018-0091446

In order to solve the above problems, the present invention is to provide a battery module capable of reducing manufacturing cost while reliably blocking an explosion by reliably blocking current when the temperature inside the battery module rises abnormally, and a device including the same. The purpose.

In addition, an object of the present invention is to provide a battery module capable of minimizing an increase in volume of the battery module while adding a member for blocking current, and a device including the same.

A battery module according to the present invention for solving the above problems includes at least one battery cell 100 including a positive electrode lead 110 and a negative electrode lead 120; A bus bar 200 having one or more slits 210 formed thereon and connected to the positive lead 110 and the negative lead 120; A bus bar frame 300 supporting the bus bar 200; And a current blocking member 400 that cuts at least one of the positive lead 110 and the negative lead 120, wherein the current blocking member 400 rises above a predetermined temperature, the positive lead 110 ) And/or the cathode lead 120 so that the anode lead 110 and/or the cathode lead 120 can be cut, the lead cutter 410, the elastic body 420, and a bar-shaped stopper ( 430).

In addition, in the battery module according to the present invention, the positive lead 110 or the negative lead 120 is fixed to one side of the bus bar 200 after passing through the slit 210, and passing through the slit 210 The current blocking member 400 may be located in the space of the slit 210 so that the positive lead 110 and/or the negative lead 120 can be cut.

In addition, in the battery module according to the present invention, the current lead cutter 410 includes a first side portion 411 (a) facing the lead, and a second side portion positioned opposite to the first side portion 411 (a) ( 411(b)), a third side part 411(c) connecting the first side part 411(a) and the second side part 411(b), and a fourth side part 411(d)) The main body 411 comprising a; A holder 412 provided in the vicinity of the third side part 411(c) and the fourth side part 411(d) so that the lead cutter 410 may be supported on the edge of the slit 210; A vertical wall 413 connected to the second side portion 411 (b) and to which one side of the elastic body 420 is fixed; And it may include a guide member for supporting the stopper 430.

In addition, in the battery module according to the present invention, the guide member is a first guide member 414 for bending the stopper 430 at a first angle, while preventing the stopper 430 from being separated from the main body 411 One side is in contact with the upper surface of the first guide member 414 and the other side is in contact with the upper surface of the main body 411 so that it can be bent at a second angle, and the second guide member 415 and the stopper 430 are at a third angle. It is preferable to include a second guide member 415 and a third guide member 416 positioned at a predetermined distance apart from the holder 412 to be bent.

In addition, in the battery module according to the present invention, it is preferable that the stopper 430 is a shape memory alloy that shrinks when the temperature increases.

In addition, in the battery module according to the present invention, it is preferable that the bus bar 200 is further provided with a guide hole 220 capable of accommodating one side of the stopper 430.

In addition, in the battery module according to the present invention, the elastic body 420 is preferably a coil shape, and more preferably made of a spring steel (KS D 3701).

In addition, in the battery module according to the present invention, the lead cutter 410 is preferably made of an insulating material, and the insulating material may be any one or more of plastic and ceramic.

In addition, in the battery module according to the present invention, a support member 440 for in close contact with one end surface of the slit 210 may be further provided at the other end of the elastic body 420.

In addition, the present invention is characterized in that it is a device including the battery module described above.

A battery module with a current blocking function according to the present invention and a device including the same are provided with a current blocking member including a stopper made of a shape memory alloy, an elastic body and a lead cutter, so that the temperature in the battery module is abnormally increased. Even so, there is an advantage that the lead can be reliably cut and thus an accident due to thermal runaway can be prevented in advance.

In addition, the battery module with a current blocking function and a device including the same according to the present invention minimizes an increase in manufacturing cost because the movement of the current blocking member is controlled through a trigger method that can minimize the amount of use of the shape memory alloy. can do.

In addition, the battery module with a current blocking function and a device including the same according to the present invention have an advantage that the volume of the battery module does not increase because the current blocking member is mounted in the slit space of the bus bar.

1 is a perspective view of a battery module according to a preferred embodiment of the present invention.
FIG. 2 is an enlarged view of portion "A" of FIG. 1.
3 is a perspective view of the current blocking member viewed from various angles
4 is a view for explaining a coupling structure between a holder of a current blocking member and a bus bar.
5 is a view for explaining a coupling structure between a stopper of a current blocking member and a bus bar.
6 is a perspective view showing a modified example of the current blocking member
7 is a view for explaining a coupling structure between the modified current blocking member shown in FIG. 6 and a bus bar.
8 is a view showing a position of a current blocking member in a state in which the battery module operates normally and a position of a current blocking member in an abnormally operating state.

In the present application, terms such as "include", "have" or "have" are intended to designate the presence of features, numbers, steps, components, parts, or combinations thereof described in the specification, but one or more other It is to be understood that the presence or addition of features, numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of being excluded.

In addition, the same reference numerals are used for parts having similar functions and functions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only a case in which it is directly connected, but also a case in which it is indirectly connected with another element interposed therebetween. In addition, the inclusion of a certain component does not exclude other components unless specifically stated to the contrary, but means that other components may be further included.

Hereinafter, a battery module having a current blocking function according to the present invention will be described.

1 is a perspective view of a battery module according to a preferred embodiment of the present invention, and FIG. 2 is an enlarged view of a portion "A" of FIG. 1.

1 and 2, a battery module according to a preferred embodiment of the present invention includes at least one battery cell 100, a bus bar 200, a bus bar frame 300, and a current blocking member 400. Including.

The battery cell 100 includes a cell assembly and a case, wherein the cell assembly is a jelly-roll type cell assembly having a structure in which a separator is interposed between a long sheet-shaped positive electrode and a negative electrode, and then wound, or a rectangular positive electrode and a negative electrode are formed as a separator. A stacked cell assembly consisting of unit cells of a structure stacked in a state interposed therebetween, a stack-folding cell assembly in which the unit cells are wound by a long separation film, or a state in which the unit cells are interposed between the separators It may be formed of a lamination-stack type cell assembly that is stacked and attached to each other, but is not limited thereto.

The cell assembly as described above is embedded in a case, and the case is typically made of a laminate sheet structure of an inner layer/metal layer/outer layer. Since the inner layer is in direct contact with the cell assembly, it must have insulation and electrolyte resistance, and for sealing with the outside, that is, the sealing area where the inner layers are thermally bonded must have excellent thermal bonding strength. The material of the inner layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, polybutylene, etc., and polyurethane resins and polyimide resins having excellent chemical resistance and sealing properties, but is not limited thereto, Polypropylene, which has excellent mechanical properties such as tensile strength, stiffness, surface hardness, and impact strength, and chemical resistance are most preferred.

The metal layer in contact with the inner layer corresponds to a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside, and an aluminum film film having a light weight and excellent formability may be used as a preferable material for the metal layer.

In addition, an outer layer is provided on the other side of the metal layer, and this outer layer can use a heat-resistant polymer having excellent tensile strength, moisture permeability and air permeation prevention properties to secure heat resistance and chemical resistance while protecting the electrode assembly. Nylon or polyethylene terephthalate may be used as an example, but is not limited thereto.

Meanwhile, the leads made of the positive lead 110 and the negative lead 120 have a structure in which the positive and negative tabs of the cell assembly are electrically connected to each other and then exposed to the outside of the case, and such a battery cell is generally known. Since they correspond to the existing configurations, a more detailed description will be omitted.

In order for the battery cells to be electrically connected inside the battery module, the electrode leads are connected to each other, and the connection portion may be fixed in contact with the bus bar by welding or the like to maintain such a connection state. In other words, the battery cells of the battery module may have parallel and/or series electrical connection. To connect in parallel, electrode leads of the same polarity are connected to each other to the busbar, and electrode leads of different polarities are connected in series. Are connected to each other on the bus bar

1 and 2, in the battery module of the present invention, in order to connect one positive lead 110 and one negative lead 120 in series with each other, three slits 210 are formed in the middle. A bus bar 200 is provided. In addition, one of the positive lead 110 or the negative lead 120 is bent through the slit 210 and then bonded to the upper surface of the bus bar 200, and the other is After extending to, it is bonded to the upper surface of the bus bar 200.

Here, in the accompanying drawings, a bus bar 200 provided with one slit is shown as an example, but it is obvious that a bus bar having two or more slits may be used depending on the number of battery cells, a serial or parallel connection structure, etc. .

Meanwhile, in order to fix the bus bar 200, a bus bar frame 300 is located near the bus bar 200, and the bus bar frame 300 is manufactured separately from the housing 500 and then combined or 500 may be formed integrally so that the bus bar 200 may be formed in itself.

Subsequently, the current blocking member 400 is positioned in the space portion of the slit 210, more specifically, in front of or behind the anode lead 110 or the cathode lead 120. When the inside of the battery module rises above a predetermined temperature, the current blocking member 400 cuts the lead by moving in the direction of the anode lead 110 or the cathode lead 120 located nearby, and consequently blocks the flow of current. Perform.

3 is a perspective view of the current blocking member viewed from various angles, FIG. 4 is a view for explaining a coupling structure between a holder of the current blocking member and a bus bar, and FIG. 5 is a diagram illustrating a coupling structure of a stopper of the current blocking member and a bus bar. It is a drawing for.

First, referring to FIG. 3, the current blocking member 400 will be described. The current blocking member 400 includes a lead cutter 410, an elastic body 420, and a stopper 430.

The lead cutter 410 has a predetermined thickness and a main body 411 having a substantially rectangular shape, a holder 412 for connecting the current blocking member 400 to the edge of the slit 210, a vertical wall 413, and a plurality of It may be formed by including a guide member (414, 415, 416) made of.

Specifically, the main body 411 is a first side portion 411 (a) facing the anode lead 110 or the cathode lead 120, and a second side portion positioned opposite to the first side portion 411 (a) (411(b)), the third side part 411(c) and the fourth side part 411(d) respectively connecting the first side part 411(a) and the second side part 411(b) Including. Here, the first side portion 411 (a) is preferably formed to have a sharp edge cross section so that the anode lead 110 or the cathode lead 120 can be quickly cut, but the thickness of the main body 411 is reduced. It is not particularly limited as long as it is formed in a shape that can cut the anode lead 110 or the cathode lead 120.

A pair of holders 412 located in the vicinity of the third side portion 411 (c) and the fourth side portion 411 (d) of the main body 411 respectively are the lead cutter 410 in the space portion of the slit 210 To locate.

Referring to FIG. 4 together, the holder 412 has an approximately'C' shape, and the upper, side and lower sides of both sides of the circumference of the slit 210 are positioned perpendicular to the direction in which the main body 411 moves. The main body 411 is positioned in close contact with the slit 210 and slides back and forth in the direction of the anode lead 110 or the cathode lead 120 while the main body 411 is positioned in the space within the slit 210.

Referring to FIG. 3 again, the vertical wall 413 is described, and the vertical wall 413 is bent at a substantially right angle at the second side portion 411 (b) and then extends upward for a predetermined length, and the vertical wall 413 ) One side of the elastic body 420 is fixed so that the elastic body 420 can contract or expand in a direction opposite to the outer surface, that is, the first side portion 411(a). In addition, the vertical wall 413 is formed to be slightly recessed from the edge of the second side portion 411 (b) in the direction of the first side portion 411 (a), which is the first side portion 411 (a) and the second side portion It is to minimize the width of the main body 411, which can be defined as the distance between (411(b)).

A part of the guide member fixed to one side of the main body 411 is a current blocking member 400 to prevent the main body 411 from moving in the direction of the anode lead 110 or the cathode lead 120 when the temperature inside the module is normal. ) Is fixed, and, on the contrary, when the temperature rises abnormally, the current blocking member 400 performs a function of releasing the fixing so that it can move.

This guide member is composed of a first guide member 414, a second guide member 415, and a third guide member 416. The first guide member 414 has one side of the rod-shaped stopper 430 facing the third side portion 411 (c) or the fourth side portion 411 (d) in the direction of the second side portion 411 (b). It is for bending at a first angle, more specifically at a right angle, and has a'b' shape.

The second guide member 415 is bent at a right angle so that the stopper 430 bent at a right angle can face a second angle, more specifically, the stopper 430 in the other direction, and the stopper 430 is the main body 411 ), one side is in contact with the upper surface of the first guide member 414 and the other side is fixed to the upper surface of the main body 411 so as to prevent separation.

The third guide member 416 is to be bent again at a right angle so that one side of the stopper 430 bent by the second guide member 415 faces the second side portion 411 (b), and the second guide member 415 and the holder 412 and are located spaced apart a predetermined distance.

Due to the first to third guide members 414, 415, and 416 having the above configuration, the stopper 430 is mounted on the main body 411 while being bent at a predetermined angle.

Meanwhile, as described above, the elastic body 420 has one side fixed to the vertical wall 413 and the other side is in close contact with the edge of one side of the slit 210. Here, the elastic body 420 may be made of a conventional material capable of contraction and expansion, and may be, for example, a spring steel (KS D 3701).

After being bent at a predetermined angle by the first guide member 414, the second guide member 415, and the third guide member 416, one end faces the second side portion 411 (b), while the other end The stopper 430 protruding for a predetermined length toward the first side portion 411 (a) or the second side portion 411 (b) is made of a shape memory alloy that contracts or expands according to temperature. Specifically, the shape memory alloy may include a nickel-titanium alloy, a copper-zinc alloy, a gold-cadmium alloy, an indium-thallium alloy, and the like, and the temperature at which the volume of these shape memory alloys begins to decrease is 70° C. to 120°C. It is preferable that it is degrees.

When described in detail with reference to FIG. 5 together, when the temperature in the module is normal, the other end of the stopper 430 is inserted into the guide hole 220 of the bus bar 200 to limit the movement of the current blocking member 400. . However, when the temperature rises above a predetermined temperature, the volume contracts, so that it is separated from the guide hole 220 and thus the current blocking member 400 is changed to a movable state. Of course, there is no particular limitation as long as it is a structure capable of temporarily fixing the other end of the stopper 430 instead of the guide hole 220.

As described above, in the present invention, a rod-shaped stopper 430 that can minimize the amount of use of the shape memory alloy and an elastic body 420 that is a conventional metal material having a low cost is used to control the movement of the current blocking member by a trigger method. Therefore, it is possible to minimize an increase in manufacturing cost.

Meanwhile, a lead cutter 410 including a main body 411, a holder 412, a vertical wall 413, a first guide member 414, a second guide member 415 and a third guide member 416 Is an insulating material, for example, may be any one or more of plastic and ceramic, but the insulating material is not particularly limited.

The coupling method of the elastic body 420 and the main body 411 is not particularly limited, but as an example, in the case of the coil-shaped elastic body 420, one end of the coil is passed through a hole (not shown) of the main body 411 to be fixed. can do.

6 is a perspective view showing a modified example of the current blocking member. Since it is the same as that of FIG. 3 except for the support member 440, only different configurations will be described below.

In the modified example of the current blocking member, a support member 440 that can be detachably coupled to the other end of the elastic body 420 is additionally provided. Specifically, the support member 440 having an approximately cylindrical shape has a seating groove 441 on the outside to accommodate the elastic body 420 so that the support member 440 can be fastened or separated into the elastic body 420 through a screwing method. Has been. In addition, a receiving groove 442 is provided at one end so as to be simultaneously supported and fixed to the upper and lower surfaces of the circumference of the slit 210.

Referring to Fig. 7 which is a diagram for explaining the coupling structure between the deformed current blocking member and the bus bar, and explaining the operation relationship, the inner side of the elastic body 420 and the support member so that the receiving groove 442 protrudes slightly. (440) The seating grooves 441 of the outer circumferential surface are fastened to each other, and the receiving groove 442 is in close contact with the upper and lower surfaces of the circumferential portion of the slit 210.

Accordingly, the elastic body 420 can accurately move in the horizontal direction within the slit 210 of the bus bar 200, and it is possible to reliably prevent the elastic body 420 from being separated from the circumference of the slit 210.

8 is a view showing a position of a current blocking member in a state in which the battery module operates normally and a position of the current blocking member in an abnormally operating state.

Referring to the operating state of the battery module according to the present invention, first, in a normal state, as shown in Fig. 8(a), the lead cutter 410 and the positive electrode lead 110 are spaced apart a predetermined distance or are simply in contact. That is, although the elastic body 420 is located between the slit 210 of the bus bar 200 and the vertical wall 413, the stopper 430 made of the shape memory alloy does not shrink and is originally because the battery module operates normally. It is in a state of being inserted into the guide hole 220 of the bus bar 200 to maintain the volume of.

However, when the battery module is in an abnormally operating state such as overcurrent or high temperature and the temperature rises, the stopper 430 contracts and deviates from the guide hole 220. At this time, since the elastic body 420 between the slit 210 and the vertical wall 413 always exerts a force to expand, the lead cutter 410 moves in the direction of the anode lead 110, and eventually the first side portion 411 The anode lead 110 is cut by (a)) (Fig. 8(b)). Therefore, the battery module according to the present invention can secure stability against an abnormal operating state by blocking the flow of current through the above principle.

The battery module as described above can be applied to various devices. Such a device may be applied to a vehicle such as an electric bicycle, an electric vehicle, or a hybrid, but is not limited thereto and may be applied to various devices capable of using a secondary battery.

Specific parts of the present invention have been described in detail above, and for those of ordinary skill in the art, these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereby. It is obvious to those skilled in the art that various changes and modifications are possible within the scope and scope of the technical idea, and it is natural that such modifications and modifications fall within the appended claims.

100: battery cell
110: positive lead
120: negative lead
200: bus bar
210: slit
220: guide
300: busbar frame
400: current blocking member
410: lead cutter
411: main body
411(a): first side part 411(b): second side part
411(c): third side portion 411(d): fourth side portion
412: holder
413: vertical wall
414: first guide member
415: second guide member
416: third guide member
420: elastic body
430: stopper
440: support member
441: seating groove 442: receiving groove
500: case

Claims (12)

At least one battery cell including a positive lead and a negative lead;
A bus bar having at least one slit formed therein and connected to the positive lead and the negative lead;
A bus bar frame supporting the bus bar; And
Including a current blocking member for cutting at least one of the positive lead and the negative lead,
The current blocking member includes a lead cutter, an elastic body, and a bar-shaped stopper so that when the current blocking member rises above a predetermined temperature, it moves in the direction of the positive electrode lead and/or the negative electrode lead to cut the positive electrode lead and/or the negative electrode lead. A battery module, characterized in that.
The method of claim 1,
The positive lead or the negative lead is fixed to one side of the busbar after passing through the slit,
The battery module, wherein the current blocking member is located in the slit space so that the positive lead and/or the negative lead through the slit can be cut.
The method of claim 1,
The current lead cutter,
A main body including a first side portion facing a lead, a second side portion positioned opposite to the first side portion, a third side portion connecting the first side portion and the second side portion, and a fourth side portion respectively; A holder provided in the vicinity of the third side portion and the fourth side portion, respectively, so that the lead cutter may be supported on the edge of the slit; A vertical wall connected to the second side portion and to which one side of the elastic body is fixed; And a guide member for supporting the stopper.
The method of claim 1,
The guide member is a first guide member for bending the stopper at a first angle, one side is in contact with the upper surface of the first guide member and the other side is in contact with the first guide member so that the stopper can be bent at a second angle while preventing separation from the main body. A battery module comprising a second guide member positioned on the upper surface of the body, and a third guide member positioned at a predetermined distance apart from the second guide member and the holder so that the stopper can be bent at a third angle.
The method of claim 1,
The battery module, wherein the stopper is a shape memory alloy that shrinks when the temperature increases.
The method of claim 5,
The battery module, characterized in that the bus bar further includes a guide hole for accommodating one side of the stopper.
The method of claim 5,
The battery module, characterized in that the elastic body has a coil shape.
The method of claim 7,
The battery module, characterized in that the elastic body is made of a spring steel (KS D 3701).
The method of claim 1,
The lead cutter is a battery module, characterized in that made of an insulating material.
The method of claim 9,
The insulating material is a battery module, characterized in that at least one of plastic and ceramic.
The method of claim 7,
A battery module, characterized in that a support member for intimate contact with the end surface of the slit is further provided at the other end of the elastic body.
A device comprising the battery module of any one of claims 1 to 11.

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