KR20210080096A - Battery module and battery pack including the same - Google Patents

Abstract

A battery module according to an embodiment of the present invention includes: a battery cell stack in which a plurality of battery cells including an electrode lead are stacked; a bus bar connected to the electrode lead; a sensing assembly positioned on the battery cell stack; and a connecting member connecting the bus bar and the sensing assembly. The connecting member includes a contact unit coming in contact with the bus bar and a spring unit bringing the contact unit in contact with the bus bar. The spring unit is positioned at a central unit of the contact unit.

Description

A battery module and a battery pack including the same {BATTERY MODULE AND BATTERY PACK INCLUDING THE SAME}

The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module including a plurality of battery cells connected to each other through a bus bar, and a battery pack including the same.

Secondary batteries that are easy to apply according to product groups and have electrical characteristics such as high energy density are universally applied to electric vehicles or hybrid vehicles driven by an electric drive source, as well as portable devices, and power storage devices. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency in that not only the primary advantage of being able to dramatically reduce the use of fossil fuels but also the fact that no by-products are generated from the use of energy.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries, so charging and discharging are free and easy. , the self-discharge rate is very low and the energy density is high.

Such a lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are applied, respectively, are disposed with a separator interposed therebetween, and a casing for sealing and housing the electrode assembly together with an electrolyte, that is, a battery case.

In general, a lithium secondary battery may be classified into a prismatic secondary battery in which an electrode assembly is embedded in a metal can and a pouch-type secondary battery in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the exterior material.

While one to three battery cells per device are used in small mobile devices, medium and large-sized devices such as automobiles require high output and high capacity. Accordingly, a medium or large-sized battery module in which a plurality of battery cells are electrically connected is used.

Since it is desirable that the mid- to large-sized battery module be manufactured as small as possible in size and weight, prismatic batteries and pouch-type batteries that can be stacked with high integration and have a small weight to capacity are mainly used as battery cells of the medium and large-sized battery modules.

On the other hand, when configuring a battery pack by connecting a plurality of battery cells in series/parallel, a battery module composed of a plurality of battery cells is configured, and other components are added to the at least one battery module to configure the battery pack. method is common.

Such a battery module includes a battery cell stack in which a plurality of battery cells are stacked, a bus bar connecting the plurality of battery cells, and a sensing assembly positioned on the battery cell stack to measure the voltage and temperature of the battery cells. can be In this case, conventionally, a method such as welding is used to connect the bus bar and the sensing assembly. Accordingly, this additional welding process was required in the manufacturing process. In addition, for such welding, one end of the sensing assembly had to be positioned outside the bus bar, and the welding part had to be exposed to the outside.

An object of the present invention is to provide a battery module with improved manufacturing processability by more easily connecting a bus bar and a sensing assembly, and a battery pack including the same.

However, the problems to be solved by the embodiments of the present invention are not limited to the above problems and may be variously expanded within the scope of the technical idea included in the present invention.

A battery module according to an embodiment of the present invention includes: a battery cell stack in which a plurality of battery cells including electrode leads are stacked; a bus bar connected to the electrode lead; a sensing assembly positioned on the battery cell stack; and a connecting member connecting the bus bar and the sensing assembly, wherein the connecting member comprises a contact portion contacting the bus bar and a spring portion contacting the contact portion to the bus bar, wherein the spring portion is located at the center of the contact portion do.

The contact part may have a plate shape, and the spring part may be a plate spring.

The spring part may be bent by protruding in a direction opposite to a direction in which the bus bar is located.

The contact part and the spring part may be integrated.

One end of the spring part may be connected to the contact part, and an end other than the one end may be spaced apart from the contact part.

The battery module includes a bus bar frame positioned on the front and rear surfaces of the battery cell stack, respectively, the bus bar is mounted on the bus bar frame, and the connecting member is positioned between the bus bar and the bus bar frame. can

The contact portion may contact the bus bar, and the spring portion may contact the bus bar frame.

The bus bar frame may include a separation preventing part protruding toward the connecting member.

The separation preventing unit may include an outer separation preventing unit disposed along the outer periphery of the spring unit.

A through hole may be formed in the spring portion, and the separation preventing portion may include an inner separation preventing portion passing through the through hole.

The connection member may include at least one coupling part coupling the connection member and the sensing assembly, and the coupling part may be bent after passing through the sensing assembly.

The sensing assembly may be a flexible printed circuit (FPC) or a flexible flat cable (FFC).

According to embodiments of the present invention, since the bus bar and the sensing assembly can be more easily connected without welding by using a connection member including a spring part, manufacturing processability and cost can be reduced.

1 is an exploded perspective view of a battery module according to an embodiment of the present invention.
FIG. 2 is a perspective view of a battery cell included in the battery module of FIG. 1 .
3 is a front view of the battery cell stack and the first bus bar frame included in the battery module of FIG. 1 .
FIG. 4 is a partial view showing an enlarged portion "A" of FIG. 3 .
FIG. 5 is a cross-sectional view taken along line B-B' of FIG. 4 .
6 is a partial view of a portion “C” of FIG. 3 viewed from another angle.
7 is a perspective view of a connection member according to an embodiment of the present invention.
8 is a partial view for explaining a connection member and a first bus bar frame according to a modified embodiment of the present invention.
9 is a partial view illustrating a state in which the connecting member of FIG. 8 and the first bus bar frame are in contact with each other.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar elements throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness of some layers and regions are exaggerated.

Also, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, it includes not only cases where it is “directly on” another part, but also cases where another part is in between. . Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. In addition, to be "on" or "on" the reference portion means to be located above or below the reference portion, and to necessarily mean to be located "on" or "on" in the direction opposite to gravity no.

In addition, throughout the specification, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

In addition, throughout the specification, when referring to "planar", it means when the target part is viewed from above, and "in cross-section" means when viewed from the side when a cross-section of the target part is vertically cut.

1 is an exploded perspective view of a battery module according to an embodiment of the present invention.

Referring to FIG. 1 , a battery module 100 according to an embodiment of the present invention includes a battery cell stack 200 in which a plurality of battery cells 110 including an electrode lead 150 are stacked; a bus bar 300 connected to the electrode lead 150 ; a sensing assembly 400 positioned on the battery cell stack 200; and a connecting member connecting the bus bar 300 and the sensing assembly 400 . The connection member will be described later in detail with reference to FIGS. 3 to 7 .

FIG. 2 is a perspective view of the battery cell 110 included in the battery module 100 of FIG. 1 .

Referring to FIG. 2 , the battery cell 110 is preferably a pouch-type battery cell. For example, the battery cell 110 according to the present embodiment has a structure in which two electrode leads 150 face each other and protrude from one end 114a and the other end 114b of the battery body 113, respectively. has In more detail, the electrode lead 150 is connected to the electrode assembly (not shown) and protrudes from the electrode assembly (not shown) to the outside of the battery cell 110 .

Meanwhile, in the battery cell 110 , both ends 114a and 114b of the battery case 114 and one side 114c connecting them are adhered in a state in which an electrode assembly (not shown) is accommodated in the battery case 114 . It can be manufactured by In other words, the battery cell 110 according to the present embodiment has a total of three sealing parts 114sa, 114sb, 114sc, and the sealing parts 114sa, 114sb, 114sc are sealed by a method such as thermal fusion. , the other one side may be formed of a connection part 115 .

Referring back to FIG. 1 , the battery cells 110 of FIG. 2 may be stacked along the y-axis direction to form the battery cell stack 200 . Accordingly, the electrode leads 150 of each of the plurality of battery cells 110 protrude toward the front (x-axis direction) and the rear surface (the opposite direction of the x-axis) of the battery cell stack 200 .

According to the direction in which the electrode lead 150 protrudes, the bus bar frames 310 and 320 may be respectively positioned on the front and rear surfaces of the battery cell stack 200 (in the x-axis direction and the x-axis direction opposite direction). Specifically, the first bus bar frame 310 may be positioned on the front surface (x-axis direction) of the battery cell stack 200 , and the second bus bar frame 310 may be positioned on the rear surface (opposite the x-axis direction) of the battery cell stack 200 . A bus bar frame 320 may be positioned.

3 is a front view of the battery cell stack 200 and the first bus bar frame 310 included in the battery module of FIG. 1 . Specifically, the first bus bar frame 310 combined with the battery cell stack 200 is viewed from the opposite direction of the x-axis.

1 to 3 , at least one bus bar 300 is mounted on the first bus bar frame 310 , and the electrode lead 150 protruding from the battery cell 110 is attached to the first bus bar frame. After passing through the slit formed in the 310 , it may be bent and connected to the bus bar 300 . There is no particular limitation on the method of such a connection, but they may be connected by welding to each other. As described above, since the electrode leads 150 of the battery cells 110 are connected to the bus bar 300 , the battery cells 110 may be electrically connected to each other.

Meanwhile, in the first bus bar frame 310 , in addition to the bus bar 300 , a part of the sensing assembly 400 positioned on the battery cell stack 200 and a module connector 410 connected to the sensing assembly 400 are provided. can be located

The sensing assembly 400 may be a flexible printed circuit (FPC) or a flexible flat cable (FFC).

The sensing assembly 400 senses the voltage and temperature of the plurality of battery cells 110 , and transmits electrical information to a Battery Mamagement System (BMS) through the module connector 410 , and the overvoltage of each battery cell 110 . , overcurrent, overheating, and other phenomena can be detected. Accordingly, the sensing assembly 400 may include a voltage sensing circuit and a temperature sensing circuit.

Figure 4 is a partial view showing an enlarged portion "A" of Figure 3, Figure 5 is a cross-sectional view taken along the cutting line B-B' of Figure 4, Figure 6 is the portion "C" of Figure 3 from another angle It is a partial view, and FIG. 7 is a perspective view of the connecting member 500 according to an embodiment of the present invention. In this case, the illustration of the bus bar is omitted in FIG. 6 for convenience of description.

4 to 7 , the battery module 100 according to the present embodiment includes a connection member 500 connecting the bus bar 300 and the sensing assembly 400 . The connection member 500 may include a conductive material, and voltage information of the battery cells 110 may be transmitted to the sensing assembly 400 through the bus bar 300 through the connection member 500 . .

The connecting member 500 includes a contact portion 510 in contact with the bus bar 300 and a spring portion 520 for bringing the contact portion 510 into close contact with the bus bar 300 , and the spring portion 520 includes the contact portion ( 510) may be located in the center. In other words, the contact part 510 may be positioned along the outer periphery of the spring part 520 .

The contact part 510 may have a plate shape, and the spring part 520 may be a plate spring. The contact portion 510 is formed in a plate shape to form a large contact area with the bus bar 300 , and the spring portion 520 is configured as a leaf spring to effectively attach the contact portion 510 to the bus bar 300 in a limited space. can be attached. To this end, the spring part 520 of the leaf spring may protrude and bend in a direction opposite to the direction in which the bus bar 300 is located (the opposite direction to the x-axis).

Meanwhile, as shown in FIGS. 6 and 7 , the contact part 510 and the spring part 520 according to the present embodiment are preferably integrated. That is, instead of providing a separate elastic member, the connecting member 500 itself may include the spring portion 520 of the leaf spring. Accordingly, the limited space can be efficiently utilized, and the connection member 500 is positioned between the bus bar 300 and the first bus bar frame 310 only between the bus bar 300 and the sensing assembly 400 . electrical connection is possible. In addition, the elastic force of the spring part 520 may evenly act on the contact part 510 .

More specifically, in the spring part 520 , one end 521 may be connected to the contact part 510 , and the other end 522 , except for one end 521 , may be spaced apart from the contact part 510 . With this structure, the spring part 520 may be bent in a direction opposite to the direction in which the bus bar 300 is located (opposite the x-axis direction) while being integrated with the contact part 510 .

In addition, the connection member 500 may include at least one coupling part 530 protruding for coupling with the sensing assembly 400 . Specifically, the coupling part 530 formed on the connection member 500 may pass through the sensing assembly 400 and then be bent, so that the connection member 500 and the sensing assembly 400 may be coupled.

Conventionally, a method such as welding is used to connect the bus bar 300 and the sensing assembly 400 . Accordingly, this additional welding process was required in the manufacturing process. In addition, for such welding, one end of the sensing assembly 400 had to be positioned outside the bus bar 300 , and the welding part had to be exposed to the outside.

On the other hand, according to the present embodiment, the electrical connection between the bus bar 300 and the sensing assembly 400 is achieved only by locating the connecting member 500 between the bus bar 300 and the first bus bar frame 310 . This makes the conventional welding process unnecessary. Accordingly, in manufacturing the battery module 100 , it is possible to improve manufacturing processability and reduce costs.

In addition, since the connecting member 500 is positioned between the bus bar 300 and the first bus bar frame 310 , naturally one end of the sensing assembly 400 and the connecting member 500 are positioned outside the bus bar 300 . Since it can be located inside, it is possible to protect one end of the sensing assembly 400 and the connection member 500 .

Referring back to FIG. 5 , as described above, the bus bar 300 is mounted on the first bus bar frame 310 , and the connecting member 500 is connected to the bus bar 300 and the first bus bar frame 310 . can be located between At this time, the contact portion 510 may contact the bus bar 300 , and the spring portion 520 may contact the first bus bar frame 310 .

Specifically, the bus bar 300 is inserted into the fixing part 311 of the first bus bar frame 310 so that the bus bar 300 is not separated in the x-axis direction and can be stably mounted. In addition, the spring part 520 contacts the first bus bar frame 310 to bring the contact part 510 into close contact with the bus bar 300 . The bus bar 300 fixed by the fixing part 311 is not pushed in the x-axis direction even by the elastic force of the spring part 520 , and all parts of the contact part 510 come into strong contact with the bus bar 300 . Electricity is made between the 300 and the connecting member 500 .

Meanwhile, although the above description has been made based on the first bus bar frame 310 , according to the present embodiment, the configuration of the connecting member 500 may be equally applied to the second bus bar frame 320 .

In addition, although the description has been made based on the bus bar 300 located on the rightmost side in FIG. 1 , the configuration of the connecting member 500 may be equally applied to other bus bars 300 .

Hereinafter, a connection member and a first bus bar frame according to a modified embodiment of the present invention will be described together with FIGS. 8 and 9 . In FIGS. 8 and 9 , illustration of the bus bar is omitted for convenience of description.

8 is a partial view for explaining a connecting member 500a and a first bus bar frame 310a according to a modified embodiment of the present invention, and FIG. 9 is a connecting member 500a and a first bus of FIG. It is a partial view showing a state that the bar frame 310a is in contact with each other.

8 and 9 , the connection member 500a according to this embodiment includes a contact part 510a and a spring part 520a, is connected to the sensing assembly 400, and a bus bar (not shown) and It may be positioned between the first bus bar frames 310a. Since this is a duplicate of the above-described content, further description will be omitted.

In this case, the first bus bar frame 310a may include a separation preventing part 330 protruding in the direction of the connecting member 500a.

The separation prevention part 330 may include an outer separation prevention part 331 disposed along the outer periphery of the spring part 520a.

Specifically, the spring portion 520a may be integrated with the contact portion 510a, one end 521a is connected to the contact portion 510a, and the other end 522a excluding the one end 521a is the contact portion 510a. can be separated from

The outer separation preventing part 331 may be disposed along the remaining end 522a of the outer periphery of the spring part 520a. The outside separation preventing portion 331 may be disposed along at least a portion of the remaining end 522a, but is preferably disposed along all of the remaining end 522a as shown in FIG. 8 .

In addition, the outer separation preventing part 331 may be configured to be spaced apart at regular intervals, but it is preferable to be arranged so as to be connected as shown in FIG. 8 . That is, the outer separation preventing part 331 may be arranged to extend along the outer periphery of the spring part 520a.

Through the external departure preventing part 331, the connecting member 500a located between the bus bar and the first bus bar frame 310a is prevented from deviate from the designated position due to external shock or vibration applied to the battery module. can

Meanwhile, a through hole 523 may be formed in the spring portion 520a , and the separation preventing portion 330 may include an inner separation preventing portion 332 passing through the through hole 523 .

When the spring part 520a of the connection member 500a comes into contact with the first bus bar frame 310a, the inner separation prevention part 332 protruding in the direction of the connection member 500a passes through the through hole 523. can

Through the inner separation preventing unit 332, the connecting member 500a located between the bus bar and the first bus bar frame 310a is prevented from deviate from the designated position due to external shock or vibration applied to the battery module. can

As shown in FIG. 9 , the connection member 500a may be stably fixed by the outer separation prevention part 331 disposed along the outer periphery of the spring part 520a. In addition, the connecting member 500a may be stably fixed by the inner separation preventing part 332 passing through the through hole 523 .

The separation preventing unit 330 according to the present embodiment may include an outer separation preventing unit 331 or an inner separation preventing unit 332 , and both the outer separation preventing unit 331 and the inner separation preventing unit 332 . may include

Meanwhile, referring back to FIG. 1 , the battery module 100 according to the present embodiments may include a module frame and an end plate 700 for accommodating the battery cell stack 200 . The module frame, as shown in Figure 1, the front (x-axis direction) and the rear surface (direction opposite to the x-axis) are open, the upper surface (z-axis direction), the lower surface (opposite the z-axis direction) and both sides (y-axis) direction and the opposite direction) may be a mono frame 600 integrated.

The battery cell stack 200 may be accommodated in a mono frame 600 having an open front (x-axis direction) and a rear surface (opposite to the x-axis direction), and the end plate 700 covers the open front and rear surfaces. can There is no particular limitation on the bonding of the mono frame 600 and the end plate 700, but may be welded to each other.

Electrical components including the battery cell stack 200 may be accommodated in the mono frame 600 and the end plate 700 to be protected.

Meanwhile, when the sensing assembly 400 and the battery cell stack 200 are accommodated in the mono frame 600 , the cover plate 900 is disposed on the sensing assembly 400 to prevent damage to the sensing assembly 400 . can be placed.

Although not specifically shown, the module frame in the present invention includes a U-shaped frame in which the lower surface (opposite the z-axis direction) and both sides (the y-axis direction and the opposite direction) are integrated and an upper plate covering the open top of the U-shaped frame. may include.

One or more battery modules according to the present embodiment described above may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.

The battery module or battery pack may be applied to various devices. Specifically, it may be applied to transportation means such as an electric bicycle, an electric vehicle, a hybrid, etc., but is not limited thereto and may be applied to various devices that can use a secondary battery.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

100: battery module
110: battery cell
200: battery cell stack
300: bus bar
310: first bus bar frame
320: second bus bar frame
400: sensing assembly
500: connection member
510: contact
520: spring part

Claims (13)

a battery cell stack in which a plurality of battery cells including electrode leads are stacked;
a bus bar connected to the electrode lead;
a sensing assembly positioned on the battery cell stack; and
a connecting member connecting the bus bar and the sensing assembly;
The connecting member includes a contact portion in contact with the bus bar and a spring portion in close contact with the contact portion to the bus bar,
A battery module in which the spring part is located in the center of the contact part. In claim 1,
The contact part is plate-shaped, and the spring part is a plate spring. In claim 2,
The spring part protrudes in a direction opposite to a direction in which the bus bar is located and is bent. In claim 1,
The contact part and the spring part are integrated battery module. In claim 4,
The spring part has one end connected to the contact part, and an end other than the one end part is spaced apart from the contact part. In claim 1,
It includes a bus bar frame positioned on the front and rear surfaces of the battery cell stack, respectively,
The bus bar is mounted on the bus bar frame,
The connecting member is a battery module positioned between the bus bar and the bus bar frame. In claim 6,
A battery module in which the contact portion is in contact with the bus bar, and the spring portion is in contact with the bus bar frame. In claim 6,
The bus bar frame is a battery module including a separation preventing part protruding in the direction of the connecting member. In claim 8,
The separation preventing portion, the battery module including an outer separation preventing portion disposed along the outer periphery of the spring portion. In claim 8,
A through hole is formed in the spring part,
The separation preventing unit, a battery module including an inner separation preventing unit passing through the through hole. In claim 1,
The connection member includes at least one coupling part for coupling the connection member and the sensing assembly,
The battery module is bent after the coupling part penetrates the sensing assembly. In claim 1,
The sensing assembly is a battery module that is a flexible printed circuit (FPC) or a flexible flat cable (FFC). A battery pack comprising at least one battery module according to claim 1 .

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