KR20210026589A - Battery module and battery pack including the same - Google Patents

Abstract

The present invention relates to a battery module capable of efficient space utilization and a battery pack including the same. The battery module comprises: a battery cell stack in which a plurality of battery cells are stacked; a U-shaped frame accommodating the battery cell stack and having an open top; an upper plate covering the battery cell stack on the upper part of the U-shaped frame; a bus bar frame respectively formed at both ends of the battery cell stack; a bridge hinged to the bus bar frame; and a temperature sensor located between the bridge and a flexible printed circuit board formed on the lower side of the bridge, wherein the bridge includes a bridge opening formed in a portion corresponding to the position of the temperature sensor.

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 capable of efficient space utilization and a battery pack including the same.

Rechargeable batteries are attracting a lot of attention as an energy source in various product lines such as mobile devices and electric vehicles. Such a secondary battery is a potent energy resource that can replace the use of conventional products that use fossil fuels, and does not generate by-products due to energy use, and thus has been in the spotlight as an eco-friendly energy source.

Recently, as the need for a large-capacity secondary battery structure, including the use of a secondary battery as an energy storage source, increases, the demand for a multi-module structure battery pack in which a number of secondary batteries are connected in series/parallel is increasing. .

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

Such a battery module may include a battery cell stack in which a plurality of battery cells are stacked, a frame accommodating the battery cell stack, and a busbar frame covering the front and rear surfaces of the battery cell stack.

1 is a perspective view showing a conventional battery module.

Referring to FIG. 1, in a conventional battery module, a battery cell stack 12 formed by stacking a plurality of battery cells 11, a frame 20 accommodating the battery cell stack 12, and a battery cell stack ( Covering the upper surface of 12), the cover plate 40 on which the circuit board 15 is formed at the bottom, the front of the busbar frame 30 and the frame 20 covering the front and rear surfaces of the battery cell stack 12 It may include an end plate 50 covering the rear and.

At this time, when the cover plate 40 is assembled, a jamming phenomenon with the frame 20 may occur, the height and weight of the battery module may increase as much as the thickness of the cover plate 40, and the frame In the process of designing (20), unnecessarily wasted space may occur.

FIG. 2 is an enlarged view of part P of FIG. 1. 3 is a partial view schematically showing the interior of portion P of FIG. 1. 4 is a cross-sectional view taken along line II′ of FIG. 2.

Referring to FIGS. 2 to 4, the conventional battery module structure of the part P of FIG. 1 will be described in more detail. First, a part of the cover plate 40 is cut to form an elastic member 21. A flexible circuit board 25 is positioned under the elastic member 21. One end of the flexible circuit board 25 is formed along the direction in which the elastic member 21 extends, and a compression pad 23 is formed between the elastic member 21 and the flexible circuit board 25. An adhesive layer 24 is formed on the upper and lower surfaces of the compression pad 23, respectively, and specifically, a first adhesive layer 24a is positioned between the compression pad 23 and the elastic member 21, and the compression pad 23 A second adhesive layer 24b may be positioned between the and the flexible circuit board 25. The first adhesive layer 24a and the second adhesive layer 24b are double-sided tapes. Using such a double-sided tape, the flexible circuit board 25 may be coupled to the elastic member 21. Here, the temperature sensor 26 is mounted between the compression pad 23 and the battery cell 11 to detect the temperature of the battery cell 11.

However, due to the structural positions of the cover plate 40 and the elastic member 21, it is difficult to check whether the temperature sensor 26 is positioned in the correct position after installation. In addition, since the temperature sensor 26 is located between the battery cell stack 12 and the upper surface of the frame 20, it may receive pressure generated from the battery cell stack 12 and the upper surface of the frame 20. In addition, through the structure of the elastic member 21 and the flexible circuit board 25 on which the temperature sensor 26 is formed, the battery cell stack 12 located at the lower side may receive pressure.

The problem to be solved by the present invention is to provide a battery module that can achieve compactness of the battery module by reducing the height and weight of the battery module.

In addition, an object to be solved of the present invention is to provide a battery module that enables the temperature sensor to be assembled at a certain position and minimizes assembly interference when assembling the temperature sensor.

In addition, the problem to be solved by the present invention is to provide a battery module that minimizes the pressure generated in the battery cell through the pressure generated in the temperature sensor and the structure around the temperature sensor.

The problems of the present invention are not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

A battery module according to an embodiment of the present invention for realizing the above object and a battery pack including the same includes a battery cell stack in which a plurality of battery cells are stacked, and a U A-shaped frame, an upper plate covering the battery cell stack above the U-shaped frame, a bus bar frame formed at both ends of the battery cell stack, a bridge hinged to the bus bar frame, and the bridge and the bridge And a temperature sensor positioned between the flexible circuit board formed at the lower side of the bridge, and the bridge includes a bridge opening formed at a portion corresponding to the position of the temperature sensor.

The bridge opening may be formed as an area including the temperature sensor when viewed from the upper side of the bridge.

Bridge side portions may be formed on both sides of the bridge opening to reinforce coupling between the front and rear sides of the bridge based on the bridge opening.

The side portion of the bridge may be formed to have a wider front-rear width than the bridge opening.

It may further include a compression pad positioned between the bridge and the flexible circuit board.

A first adhesive layer positioned between the compression pad and the bridge to couple the compression pad and the bridge may be further included.

A second adhesive layer disposed between the compression pad and the flexible circuit board and bonding the compression pad to the flexible circuit board may be further included.

The bridge may be connected to a rotation shaft formed on an upper end of the bus bar frame.

The bridge may rotate about the rotation axis in a direction in which the battery cell stack is located, so that the temperature sensor located under the bridge detects the temperature of the plurality of battery cells.

A battery module and a battery pack including the same according to an embodiment of the present invention remove the cover plate and instead provide a signal connection part formed of a flexible flat cable, thereby lowering the height of the battery module and reducing the weight of the battery module. And weight reduction can be achieved.

In addition, the battery module and the battery pack including the same according to an embodiment of the present invention provide an effect of lowering the height of the battery module by the thickness of the bridge through the bridge opening through which the temperature sensor can enter.

In addition, the battery module and the battery pack including the same according to an exemplary embodiment of the present invention provide an effect of minimizing the pressure generated in the temperature sensor and the pressure generated in the battery cell through the bridge opening.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a perspective view showing a conventional battery module.
FIG. 2 is an enlarged view of part P of FIG. 1.
3 is a partial view schematically showing the interior of portion P of FIG. 1.
4 is a cross-sectional view taken along line II′ of FIG. 2.
5 is an exploded perspective view showing a battery module according to an embodiment of the present invention.
6 is a perspective view showing a pouch-type battery according to an embodiment of the present invention.
7 is a view showing a state in which a signal connection part and a bridge are combined with a bus bar frame in the battery module of FIG. 5.
FIG. 8 is an enlarged view of part A of FIG. 7.
FIG. 9 is a view of the bridge of FIG. 8 as viewed from above.
10 is a cross-sectional view of the bridge and peripheral configuration of FIG. 8.
11 is a view as viewed from the side of FIG. 8.

The embodiments described below are illustratively shown to aid understanding of the invention, and it should be understood that the present invention may be variously modified and implemented differently from the embodiments described herein. However, in describing the present invention, when it is determined that a detailed description of a related known function or component may unnecessarily obscure the subject matter of the present invention, the detailed description and detailed illustration thereof will be omitted. In addition, the accompanying drawings are not drawn to scale to aid understanding of the invention, but dimensions of some components may be exaggerated.

The first and second terms used in the present application may be used to describe various elements, but the elements should not be limited by terms. The terms are used only for the purpose of distinguishing one component from other components.

In addition, terms used in the present application are only used to describe specific embodiments, and are not intended to limit the scope of the rights. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise", "consist of" or "consist of" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, one or It is to be understood that no further features or possibilities of the presence or addition of numbers, steps, actions, components, parts, or combinations thereof are excluded in advance.

Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS. 5 and 6.

5 is an exploded perspective view showing a battery module according to an embodiment of the present invention. 6 is a perspective view showing a pouch-type battery according to an embodiment of the present invention.

Referring to Figure 5, the battery module 100 according to an embodiment of the present invention, a battery cell stack 120 including a plurality of battery cells 110, a U-shaped top surface, front and rear open The frame 210, the upper plate 220 covering the upper part of the battery cell stack 120, the end plates 311 and 312 respectively located at the front and the rear of the battery cell stack 120, and the battery cell stack It includes a bus bar frame (310, 320) positioned between 120 and the end plates (311, 312).

The U-shaped frame 210 is formed in a plate-shaped structure bent so as to continuously surround both side surfaces and lower surfaces formed in the stacking direction of the battery cell stack 120, that is, in the Y-axis direction shown in FIG. 5. The upper plate 220 is connected to the U-shaped frame 210 and is formed in a plate-shaped structure covering the upper portion of the battery cell stack 120. The U-shaped frame 210 and the upper plate 220 are coupled by welding in a state in which the corresponding corner portions are in contact with each other, thereby forming a structure covering the upper, lower, left, and right surfaces of the battery cell stack 120.

The battery cell 110 is preferably a pouch-type battery cell. 6, in the battery cell 110 according to an embodiment of the present invention, two electrode leads 111 and 112 face each other so that one end 114a of the battery body 113 and the other end 114b Each has a structure protruding from ). The battery cell 110 is manufactured by bonding both ends 114a and 114b of the battery case 114 and a side portion 114c connecting them with the electrode assembly (not shown) stored in the battery case 114 Can be. In other words, the battery cell 110 according to the present embodiment has a total of three sealing parts (114sa, 114sb, 114sc), the sealing parts (114sa, 114sb, 114sc) is a structure that is sealed by a method such as thermal fusion. , The other side portion may be formed of the connection portion 115. The distance between both ends 114a and 114b of the battery case 114 is defined in the length direction of the battery cell 110, and a connection part with one side 114c connecting both ends 114a and 114b of the battery case 114 Between 115 may be defined in the width direction of the battery cell 110.

The connection part 115 is an area extending long along one edge of the battery cell 110, and a protrusion 110p of the battery cell 110 may be formed at an end of the connection part 115. The protrusion 110p may be formed on at least one of both ends of the connection part 115, and may protrude in a direction perpendicular to a direction in which the connection part 115 extends. The protrusion 110p may be positioned between one of the sealing portions 114sa and 114sb of both ends 114a and 114b of the battery case 114 and the connection portion 115.

The battery case 114 is generally made of a laminate structure of a resin layer/metal thin film layer/resin layer. For example, when the surface of the battery case is made of an O (oriented)-nylon layer, when a plurality of battery cells are stacked to form a medium or large battery module, they tend to slide easily due to external impact. Therefore, in order to prevent this and maintain a stable stacked structure of battery cells, a battery cell stacked body by attaching an adhesive member such as an adhesive adhesive such as a double-sided tape or a chemical adhesive bonded by a chemical reaction upon adhesion to the surface of the battery case. 120 can be formed. In this embodiment, the battery cell stack 120 is stacked in the Y-axis direction, and accommodated in the U-shaped frame 300 in the Z-axis direction, so that the battery cell stack 120 and the bottom of the U-shaped frame 300 Cooling may be performed by a thermally conductive resin layer (not shown) formed between 210a. As a comparative example of this, there is a case in which the battery cells are formed of cartridge-shaped parts, and thus the fixing between the battery cells is made by assembling the battery module frame. In this comparative example, due to the presence of the cartridge-type component, there is little or no cooling action, and the cooling may not be performed well in the height direction of the battery cell.

Before the battery cell stack 120 according to the present embodiment is mounted on the bottom portion 210a of the U-shaped frame 210, a thermally conductive resin is applied to the bottom portion 210a of the U-shaped frame 210, The thermally conductive resin may be cured to form a thermally conductive resin layer.

Thereafter, the battery cell stack 120 may be mounted on the bottom portion 210a of the U-shaped frame 210 while moving in a direction perpendicular to the bottom portion 210a of the U-shaped frame 210. At this time, the thermally conductive resin layer is positioned between the bottom portion 210a of the U-shaped frame 210 and the battery cell stack 120. The thermally conductive resin layer may serve to transfer heat generated from the battery cells 110 to the bottom of the battery module 100 and to fix the battery cell stack 120.

The width of the side portion 210b and the upper plate 220 of the U-shaped frame 210 according to the present embodiment may be the same. In other words, the edge portion along the X-axis direction of the upper plate 220 and the edge portion along the X-axis direction of the side portion 210b of the U-shaped frame 210 may directly meet and be coupled by a method such as welding.

The battery module 100 according to the present embodiment is located adjacent to the signal connection unit 400 and the signal connection unit 400 connecting the bus bar frames 310 and 320 respectively formed at both ends of the battery cell stack 120 It includes a bridge 500 to. The bridge 500 is hinged to the bus bar frame 320, and a temperature sensor 450 is positioned under the bridge 500. The signal connection part 400 may be formed of a flexible flat cable (FFC).

Conventionally, a flexible printed circuit (FPC) is provided between the bus bar frames, so that the two bus bar frames are connected through the flexible circuit board, and a cover on the top of the flexible circuit board to prevent damage to the flexible circuit board. Additional plates were installed. The cover plate was a component to be added separately from the plate corresponding to the upper plate 220 according to the present embodiment. However, according to an embodiment of the present invention, a cover plate protecting and supporting a flexible circuit board is removed, and a flexible flat cable (FFC) that does not require a protection member such as a cover plate instead of the flexible circuit board is used. The two busbar frames 310 and 320 are connected. Since it has a method and structure for covering the battery cell stack 120 by the combination of the U-shaped frame 210 and the upper plate 220, even if a flexible flat cable is used without the existing cover plate, the flexible flat cable in the assembly process Damage can be prevented.

In this way, through the connection of the two busbar frames through FFC, the height of the battery module 100 is reduced, thereby increasing the energy density of the battery module itself.

As described above, the signal connection part 400 formed of FFC according to an embodiment of the present invention is located between the upper plate 220 and the battery cell stack 120. In more detail, an insulating member (not shown) is formed on the upper side of the battery cell stack 120, and the signal connection part 400 may be located between the insulating member (not shown) and the upper plate 220. .

The signal connection part 400 is formed of a soft cable and can be bent, and since a circuit for electrical connection between busbar frames is inserted into the cable, it is easy to cope with an external shock.

7 is a view showing a state in which a signal connection part and a bridge are combined with a bus bar frame in the battery module of FIG. 5. FIG. 8 is an enlarged view of part A of FIG. 7. FIG. 9 is a view of the bridge of FIG. 8 as viewed from above. 10 is a cross-sectional view of the bridge and peripheral configuration of FIG. 8. 11 is a view as viewed from the side of FIG. 8.

Hereinafter, a temperature sensor and a peripheral configuration thereof according to an embodiment of the present invention will be described with reference to FIGS. 7 and 8.

7 and 8, the temperature sensor 450 according to an embodiment of the present invention is formed between the bridge 500 and the flexible circuit board 490 formed on the lower side of the bridge 500, the flexible circuit It may be located on the upper surface of the substrate 490. The temperature sensor 450 may be formed of a thermistor element. The thermistor device is a semiconductor device using a phenomenon in which a resistance value varies depending on temperature, and may be formed by mixing and sintering oxides such as copper, manganese, nickel, cobalt, chromium, and iron. Such thermistors have the advantage of being small in size and capable of measuring even with rapid temperature changes or fine temperature changes.

The temperature information measured by the temperature sensor 450 may be transmitted to another device outside the battery module. For example, when the temperature is measured by the temperature sensor 450, the measured temperature information is transmitted to a battery management system (BMS) outside the battery module, and may be used to control the battery module. To this end, the battery module may include a temperature measurement cable (not shown) having one end connected to the temperature sensor 450. A connector may be provided at the other end of the cable, and this connector may be connected to an external device such as a BMS.

A compression pad 480 may be positioned between the bridge 500 and the flexible circuit board 490. The compression pad 480 may be formed of polyurethane foam. Through the compression pad 480, the distance between the bridge 500 and the flexible circuit board 490 is more flexibly adjusted, and durability of the overall bridge and temperature sensor structure may be improved.

A bridge 500 is positioned above the compression pad 480, and a first adhesive layer 470a is formed between the compression pad 480 and the bridge 500 to couple the compression pad 480 and the bridge 500. I can. A flexible circuit board 490 is positioned under the compression pad 480, and a second adhesive layer 470b is formed between the compression pad 480 and the flexible circuit board 490, so that the compression pad 480 and the flexible circuit board 490 can be combined. The first adhesive layer 470a and the second adhesive layer 470b may be double-sided tapes.

Hereinafter, an installation of a temperature sensor according to an embodiment of the present invention will be described with reference to FIG. 11.

Referring to FIG. 11, the temperature sensor 450 according to an embodiment of the present invention may be installed on a flexible circuit board 490 located under the bridge 500 and coupled to the bridge. At this time, one end of the bridge 500 may be connected to the rotation shaft 495 formed at the top of the bus bar frame, and the bridge 500 connected to the rotation shaft 495 is the direction in which the battery cell 110 is located around the rotation shaft 495 It can be assembled by rotating it.

The bridge 500 and the flexible circuit board 490 can be assembled to be adjacent to the battery cell 110 through rotation, and the temperature sensor 450 installed on the flexible circuit board 490 is also adjacent to the battery cell 110. Can be assembled in position. Through this, the assembled temperature sensor 450 may detect a temperature according to heat generated from the battery cell 110.

Conventionally, there was a concern that interference with the frame may occur when the cover plate on which the temperature sensor is formed is installed, but according to an embodiment of the present invention, a signal connection part 400 is formed instead of the cover plate, and adjacent to the signal connection part 400 A rotation shaft 495 is formed there, and the bridge 500 hinged to the rotation shaft 495 is assembled into the battery module through rotation, so that interference between the bridge and surrounding components may be minimized during assembly.

In addition, conventionally, since the temperature sensor is assembled in a fixed state under the cover plate, it is difficult to check whether the temperature sensor is assembled in the correct position. However, since the temperature sensor 450 according to an embodiment of the present invention is installed on the flexible circuit board 490 coupled to the bridge 500, the temperature sensor 450 is fixed before assembling it to the rotation shaft 495. You can check if it is installed in the location, and it can be possible to adjust the location when assembling it in the wrong location.

Hereinafter, a bridge opening according to an embodiment of the present invention will be described with reference to FIGS. 8 to 10.

8 to 10, the bridge 500 according to an embodiment of the present invention includes a bridge opening 510 formed in a portion corresponding to the position of the temperature sensor 450. The bridge opening 510 may be formed as an area including the temperature sensor 450 when viewed from the upper side of the bridge 500.

If the structure of the bridge opening 510 is not formed on the upper side of the temperature sensor 450, the height of the battery module may increase as much as the thickness of the bridge located on the upper side of the temperature sensor due to the volume of the temperature sensor. The temperature sensor formed between the circuit boards receives pressure directly through the bridge and the flexible circuit board, and an error may occur in the sensor measurement value of the temperature sensor, and the pressure transmitted in the order of the frame, the bridge, the temperature sensor, and the flexible circuit board. It can be delivered to the cell.

Accordingly, according to the present invention, by forming the bridge opening 510 according to the embodiment, the temperature sensor 450 can enter the space formed by the bridge opening 510, thereby reducing the height of the battery module by the thickness of the bridge. , It is possible to reduce the vertical pressure generated in the temperature sensor 450 and the battery cell 110 by the space formed by the thickness of the opening.

Bridge side portions 520 may be formed on both sides of the bridge opening 510 to reinforce the coupling between the front and rear of the bridge 500 based on the bridge opening 510. The bridge side portion 520 may be formed of a first bridge side portion 520a formed on one side of the bridge 500 and a second bridge side portion 520b formed on the other side. The bridge side portion 520 may be formed to have a wider width in the front-rear direction than the bridge opening. Rigidity of the bridge 500 due to the formation of the bridge opening 510 may be reinforced through the bridge side portion 520.

The battery module described above may be included in the battery pack. The battery pack may have a structure in which one or more battery modules according to the present embodiment are collected and a battery management system (BMS) that manages the temperature or voltage of the battery, and a cooling device are added and packed.

The battery pack 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 vehicle, but the present invention is not limited thereto and may be applied to various devices capable of using a battery module, and this also falls within the scope of the present invention. .

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and the present invention is generally in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications may be implemented by those skilled in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

100: battery module
110: battery cell
120: battery cell stacked body
210: U-shaped frame
220: upper plate
310, 320: busbar frame
400: signal connection
450: temperature sensor
470: adhesive layer
480: compression pad
490: flexible circuit board
500: bridge
510: bridge opening
520: bridge side portion

Claims (10)

A battery cell stack in which a plurality of battery cells are stacked;
A U-shaped frame accommodating the battery cell stack and having an open top;
An upper plate covering the battery cell stack on the U-shaped frame;
Busbar frames formed at both ends of the battery cell stack;
A bridge hinged to the busbar frame; And
It includes a temperature sensor located between the bridge and the flexible circuit board formed on the lower side of the bridge,
The bridge, the battery module including a bridge opening formed in a portion corresponding to the position of the temperature sensor. In claim 1,
The bridge opening is a battery module formed in an area including the temperature sensor when viewed from an upper side of the bridge. In claim 1,
On both sides of the bridge opening, a bridge side portion is formed to reinforce the coupling between the front and rear of the bridge based on the bridge opening. In paragraph 3,
The bridge side portion is formed to have a width in the front-rear direction wider than that of the bridge opening. In claim 1,
A battery module further comprising a compression pad positioned between the bridge and the flexible circuit board. In clause 5,
A battery module further comprising a first adhesive layer positioned between the compression pad and the bridge and coupling the compression pad and the bridge. In clause 5,
A battery module further comprising a second adhesive layer positioned between the compression pad and the flexible circuit board and coupling the compression pad and the flexible circuit board. In claim 1,
The bridge is a battery module connected to a rotation shaft formed on the upper end of the bus bar frame. In clause 8,
The bridge is a battery module that rotates about the rotation axis in a direction in which the battery cell stack is located, so that the temperature sensor located under the bridge detects the temperature of the plurality of battery cells. A battery pack comprising the battery module according to claim 1.

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