KR20210127508A - Battery pack with auto disconnect bus bar - Google Patents

Abstract

The present invention relates to a battery pack including: a plurality of battery modules having an external terminal to automatically release electrical contact with the external terminal of the battery module when an abnormality such as heat generation occurs; and a bus bar which electrically connects the external terminal provided in each adjacent battery module, wherein the bus bar includes: a case; a terminal assembly including a terminal positioned inside the case and coming in electrical contact with the external terminal, and a terminal frame coupled to the terminal and having a hole through which the external terminal is inserted into the terminal; and a support unit in which one side is coupled to the terminal frame and the other side is coupled to the case.

Description

Battery pack with auto disconnect bus bar

The present invention relates to a bus bar having a novel structure that can block the current flow of the bus bar and module when an abnormal temperature occurs by applying a shape memory alloy.

As technology development and demand for mobile devices such as cell phones, laptops, camcorders, and digital cameras increase, technologies related to rechargeable batteries that can be charged and discharged are becoming active. In addition, secondary batteries are alternative energy sources for fossil fuels that cause air pollutants, such as electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and energy storage systems (ESSs). applied, etc.

An energy storage system (ESS) is a device that stores a large amount of excessively produced power in a battery and then draws it back for use when necessary. It plays a role in increasing the efficiency of power use by storing power when power usage is low and using the stored power when power demand is high. These ESSs can be broadly divided into grid system ESS, uninterruptible power supply (UPS), and home ESS.

Types of secondary batteries currently widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. The operating voltage of the unit secondary battery cell, that is, the unit battery cell, is about 2.0V to 5.0V. Therefore, when a higher output voltage is required, a plurality of battery cells may be connected in series to form a cell module assembly, and the cell module assembly may be connected in series or parallel according to the required output voltage or charge/discharge capacity. A battery module may be configured, and it is common to manufacture a battery pack by adding additional components using at least one battery module.

However, since the lithium secondary battery has a risk of explosion due to overheating, securing safety is one of the important tasks. Such overheating occurs due to various causes, one of which is an overcurrent flowing through the lithium secondary battery. When the overcurrent flows, the internal temperature of the secondary battery rapidly rises due to heat generation, and the rapid rise in temperature causes a thermal runaway, which may lead to explosion of the secondary battery.

Meanwhile, in FIGS. 1 and 2 , a bus bar 4 to which a shape memory alloy is applied that can protect the secondary battery from dangers such as ignition or explosion due to heat by quickly blocking the overcurrent flowing in the secondary battery and a battery pack including the same This is shown.

Referring to FIGS. 1 and 2 , the conventional bus bar 4 has a fastening hole through which the external terminal 3 of the battery module M is inserted and fixed to the plate-shaped bus bar 4 made of a shape memory alloy ( By providing H), the contact with the external terminal 3 is released by increasing the size of the fastening hole H above the reference temperature.

However, in the case of such a bus bar, there is a disadvantage that the contact area is narrow because the portion in contact with the external terminal only corresponds to the inner cross-section of the fastening hole. There is a risk that contact failure may occur even with deformation.

Korean Patent Publication No. 10-2015-0028073

In order to solve the above problems, the present invention provides a terminal assembly including a terminal covering the outer surface of an external terminal, and a terminal assembly to which a shape memory material is applied to separate the contact between the external terminal and the terminal at a reference temperature or higher. An object of the present invention is to provide a bus bar including a support and a battery pack including the same.

A battery pack according to the present invention for achieving the above object includes a plurality of battery modules having external terminals and a bus bar electrically connecting external terminals provided in each of the adjacent battery modules, wherein the bus bar is a case And a terminal assembly located inside the case and electrically contacting an external terminal, and a terminal assembly including a terminal frame coupled to the terminal and having a hole through which the external terminal is inserted into the terminal, and one side is coupled to the terminal frame, and the other side is It characterized in that it comprises a terminal assembly support coupled to the case.

In addition, the battery pack according to the present invention is characterized in that it is made of a shape memory material that releases the contact between the external terminal and the terminal by deforming the terminal assembly support part into a memorized form at a reference temperature or higher.

In addition, the battery pack according to the present invention is characterized in that the shape memory material is a shape memory alloy or a shape memory polymer.

In addition, the battery pack according to the present invention is characterized in that the terminal assembly support portion is in the form of a straight bar at room temperature, and the memorized form is in the form of a spring.

In addition, the battery pack according to the present invention is characterized in that the terminal assembly support part has a straight bar shape at room temperature, and the stored shape is a zigzag shape.

In addition, the battery pack according to the present invention is characterized in that the terminal assembly support part has a straight bar shape at room temperature, and the stored shape is a shape bent in one direction.

In addition, the battery pack according to the present invention is characterized in that the terminal assembly support portion has a flat plate shape at room temperature, and the stored shape is a zigzag shape.

In addition, the battery pack according to the present invention is characterized in that the terminal assembly support part is a flat plate shape at room temperature, and the stored shape is a shape curved in one direction.

In addition, the bus bar according to the present invention is a bus bar for electrical connection between a plurality of battery modules having external terminals, wherein the bus bar includes a case, a terminal assembly, and a terminal assembly support part, and the terminal assembly is disposed inside the case. It is located and includes a terminal and a terminal in electrical contact with the external terminal and a terminal frame coupled to the terminal and having a hole through which the external terminal is inserted into the terminal, the terminal assembly support part having one side coupled to the terminal frame and the other side coupled to the case characterized.

In addition, the bus bar according to the present invention is characterized in that it is made of a shape memory material that releases the contact between the external terminal and the terminal by deforming the terminal assembly support part into a memorized shape at a reference temperature or higher.

In addition, the bus bar according to the present invention is characterized in that the shape memory material is a shape memory alloy or a shape memory polymer.

In addition, the bus bar according to the present invention is characterized in that the terminal assembly support is in the form of a straight bar at room temperature, and the memorized form is in the form of a spring.

The battery pack of the present invention includes a terminal assembly support in which the bus bar electrically connecting the external terminals of the battery module is formed of a shape memory material, and automatically separates the bus bar and the external terminal when heat is generated to prevent energy concentration. have.

In addition, the battery pack of the present invention has the advantage of facilitating the flow of current by contacting the external terminal with a large area, including a terminal in which the bus bar surrounds the outer surface of the external terminal.

In addition, the battery pack of the present invention has the advantage of preventing contact failure due to deformation of the shape memory material by applying the shape memory material to the terminal assembly support part that does not directly contact the external terminal in the structure of the bus bar.

1 is a schematic diagram of a battery pack to which a bus bar made of a conventional shape memory alloy is applied.
2 is a schematic view of a bus bar made of a conventional shape memory alloy.
3 is a schematic diagram of a battery pack including a busbar of the present invention.
FIG. 4 is an enlarged view of a terminal assembly of the battery pack of FIG. 3 .
5 is a view showing a process in which the bus bar of the present invention is separated above a reference temperature.
6 and 7 are views showing various embodiments of the terminal assembly support of the present invention.
8 is a view showing an embodiment in which the terminal frame and the external terminal of the present invention are coupled.
9 is a view showing another embodiment in which the terminal frame and the external terminal of the present invention are coupled.

In the present application, terms such as “comprises”, “have” or “have” are intended to designate the existence of features, numbers, steps, components, parts, or combinations thereof described in the specification, and one or more other It is to be understood that this does not preclude the possibility of the presence or addition of features or numbers, steps, operations, components, parts, or combinations thereof.

In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. Throughout the specification, when it is said that a part is connected to another part, it 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 otherwise stated, but means that other components may be further included.

Hereinafter, a battery pack according to the present invention will be described with reference to the accompanying drawings.

3 is a schematic diagram of a battery pack including a busbar according to a first preferred embodiment of the present invention.

When the battery pack 10 is described with reference to FIG. 3 , the battery pack 10 of the present invention includes a plurality of battery modules 200 having external terminals 210 and external terminals of adjacent battery modules 200 . and a bus bar 100 for electrically connecting the 210 .

In addition, the bus bar includes the case 110 , the terminal assembly 120 in electrical contact with the external terminal 210 of the battery module 200 , and one side is coupled to the inner surface of the case 110 , and the other side is the terminal assembly 120 . ) includes a terminal assembly support 130 coupled to.

Meanwhile, looking at the terminal assembly 120 in detail with reference to FIG. 4 , the terminal assembly 120 includes a terminal 121 into which a part of the external terminal 210 is inserted and electrically contacting the external terminal 210 , and the terminal. 121 is coupled to one surface and has a hole H into which the external terminal 210 can be inserted, and includes a terminal frame 122 that is movable inside the case 110 .

The terminal 121 is preferably formed so as to have an inner shape corresponding to the outer surface of the inserted external terminal 210 so that an area of electrical contact with the inserted external terminal 210 is wide.

In addition, the terminal assembly support 130 is composed of a shape memory material. The shape memory material refers to a material exhibiting a shape memory effect. It refers to the phenomenon of returning to its original shape when it is transformed into a shape and heated again to a specific temperature.

Such shape memory materials include metals such as nickel-titanium alloys, copper-zinc alloys, gold-cadmium alloys, and shape memory polymers. .

In addition, referring to FIG. 5 , looking at the process in which the bus bar 100 of the present invention is automatically separated from the external terminal 210 above the reference temperature, below the reference temperature, the terminal assembly support 130 made of the shape memory material is a straight bar. supports the terminal frame 122 in the form of By automatically disconnecting from the external terminal 210 , the bus bar and the battery module 200 can be electrically cut off quickly.

That is, by appropriately selecting the shape memory material of the terminal assembly support 130 , the bus bar 100 can perform a function of blocking current at an appropriate temperature, thereby ensuring safety in using the secondary battery.

On the other hand, the shape of the terminal assembly support 130 can be formed in various shapes as well as the shape shown in FIG. 5 , and other embodiments thereof are shown in FIGS. 6 and 7 .

First, looking at the shape of the terminal assembly support 130 with reference to FIG. 6 , the terminal assembly support 130 may be in the form of a straight bar as shown in FIG. 6(a) below the reference temperature, and the cross-sectional shape of the straight bar is a rectangle It is possible to have a circular shape as well as a angular shape such as a back. In addition, the form above the reference temperature is not only a spring form, but also a form such as, for example, (b), (c), (d) of FIG. 6 , and a terminal frame connected by a certain degree of contraction during deformation As long as it can separate the 122 from the external terminal 210 , it is applicable without being limited to a specific shape. In addition, the number of the terminal assembly support 130 may be one as shown in FIG. 6 , and in some cases, a plurality of terminals made of the same shape memory material may be installed.

7 shows another embodiment of the terminal assembly support 130, the terminal assembly support 130 may be in the form of a flat plate as shown in FIG. 7 (a) below the reference temperature, and above the reference temperature (b) and (c) are transformed into the same shape and serve to electrically separate the terminal 121 and the external terminal 210 .

On the other hand, in order to further increase the coupling force between the external terminal 210 and the terminal assembly 120 , the external terminal 210 and the terminal frame 122 have a fastening groove 211 and a fastening protrusion P, respectively, as shown in FIG. 8 . can be formed. When the external terminal 210 is inserted into the terminal assembly 120 , the fastening protrusion P formed in the terminal frame 122 is inserted into the fastening groove 211 formed in the external terminal 210 , so that the terminal assembly 120 and the external terminal are inserted. The binding force of (210) may be further increased.

This fastening protrusion (P) is a portion protruding into the hole (H) of the terminal frame 122 is pressed toward the terminal frame 122 under a certain pressure when the external terminal 210 is inserted into the external terminal 210 . The coupling is made by protruding back to the original state from the fastening groove 211 portion of the , and the same process as the insertion can be performed even during separation. However, the structure of the fastening protrusion (P) is not limited thereto, for example, by applying a shape memory material like the terminal assembly support part 130 of the present invention, applying a constant pressure to combine the fastening protrusions (P) at a reference temperature or higher. Separation can be facilitated by deformation of the shape. In this case, the shape memory material used for the fastening protrusion P may use the same material as the terminal assembly support 130 , or may use a material having substantially the same deformation temperature as the shape memory material of the terminal assembly support 130 .

In addition, the number and size of the fastening protrusion P and the fastening groove 211 are not particularly limited, and may be appropriately selected in consideration of various conditions.

Meanwhile, FIG. 9 shows another embodiment for increasing the coupling force between the external terminal 210 and the terminal assembly 120 .

Looking in detail with reference to Figure 9, Figure 9 (a) shows the addition of the shape memory alloy nut 123 to the contact surface of the terminal frame 122 and the external terminal 210, Figure 9 (b) and (c) shows the shape of the shape memory alloy nut 123 below the reference temperature and above the reference temperature, respectively.

The shape memory alloy nut 123 may use a shape memory alloy of the same material as the terminal assembly support 130 , or an alloy having substantially the same deformation temperature as the shape memory material of the terminal assembly support 130 .

In addition, the shape memory alloy nut 123 has a deformed form in which one surface in the direction in which the external terminal is inserted is rolled inward as shown in FIG. 9 ( b ) below the reference temperature, whereby the terminal assembly 120 and the external terminal When the 210 is coupled, it serves to increase the bonding force between the two, and when the reference temperature is higher than the reference temperature, the part rolled inward is unfolded in a memorized form (same form as in FIG. 9 (c)), and the terminal assembly 120 and It is possible to facilitate the separation of the external terminal.

In addition, the battery pack of the present invention having such a structure can be applied to an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (P-HEV), an energy storage system (ESS), and the like.

As the specific part of the present invention has been described in detail above, for those of ordinary skill in the art, these specific descriptions 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 can be made within the scope and spirit of the present invention, and it is natural that such variations and modifications fall within the scope of the appended claims.

1: battery cell
2: Module case
3, 210: external terminal
4, 100: bus bar
M, 200: battery module
H: Hall
10 : battery pack
110: case
120: terminal assembly
121 : terminal
122: terminal frame
123: shape memory alloy nut
130: terminal assembly support
211: fastening groove
P: fastening protrusion

Claims (12)

a plurality of battery modules having external terminals; and
and a bus bar electrically connecting between the external terminals provided in each of the adjacent battery modules,
The bus bar includes a case;
a terminal assembly including a terminal located inside the case and electrically contacting the external terminal, and a terminal frame coupled to the terminal and having a hole through which the external terminal is inserted into the terminal; and
and a terminal assembly support part having one side coupled to the terminal frame and the other side coupled to the case.
The battery pack according to claim 1, wherein the terminal assembly support part is made of a shape memory material that releases the contact between the external terminal and the terminal by being deformed to a memorized shape at a reference temperature or higher.
The battery pack according to claim 2, wherein the shape memory material is a shape memory alloy or a shape memory polymer.
The battery pack according to claim 2, wherein the terminal assembly support part has a straight bar shape at room temperature, and the stored shape is a spring shape.
The battery pack according to claim 2, wherein the terminal assembly support part has a straight bar shape at room temperature, and the stored shape is a zigzag shape.
The battery pack according to claim 2, wherein the terminal assembly support part has a straight bar shape at room temperature, and the stored shape is a curved shape in one direction.
The battery pack according to claim 2, wherein the terminal assembly support part has a flat plate shape at room temperature, and the stored shape is a zigzag shape.
The battery pack according to claim 2, wherein the terminal assembly support part has a flat plate shape at room temperature, and the stored shape is a curved shape in one direction.
A bus bar for electrical connection between a plurality of battery modules having external terminals, the bus bar comprising:
The bus bar includes a case, a terminal assembly and a terminal assembly support,
The terminal assembly may include a terminal positioned inside the case and in electrical contact with the external terminal; and
A terminal frame coupled to the terminal and having a hole through which the external terminal is inserted into the terminal,
The terminal assembly support portion is a bus bar, characterized in that one side is coupled to the terminal frame and the other side is coupled to the case.
The bus bar according to claim 9, wherein the terminal assembly support part is made of a shape memory material that releases the contact between the external terminal and the terminal by being deformed into a memorized shape at a reference temperature or higher.
The bus bar according to claim 10, wherein the shape memory material is a shape memory alloy or a shape memory polymer.
The bus bar according to claim 10, wherein the terminal assembly support part has a straight bar shape at room temperature, and the stored shape is a spring shape.

Images