KR20130110943A - Battery module of novel structure and battery pack comprising the same - Google Patents

Abstract

PURPOSE: A battery module has excellent structural stability, has a compact structure, is simply assembled, and is formed of various battery cells selected as necessary. CONSTITUTION: A battery module (300) comprises a unit module laminate (600) on which two or more unit modules are laminated; a module case (360) in which the unit modules are installed in series and electrode terminal parts of the unit modules are open; a busbar assembly (350) which is installed in the electrode terminal part and in which one or more busbars for connecting the unit modules in series are in an exposed state in order to weld the busbars from outside; and an electrically insulative cover (310) surrounding the busbar assembly.

Description

Battery Module with Novel Structure and Battery Pack Including It {Battery Module of Novel Structure and Battery Pack Comprising the Same}

The present invention relates to a battery module having excellent structural stability and a battery pack including the same. More particularly, two or more battery cells are mounted in a cell cover in a state in which they are connected in parallel to each other, and the electrode terminal connecting portions of the battery cells are vertically bent. The unit modules protruding from the outside of the cell cover are stacked in a unit module stack of two or more numbers, and the unit modules of the unit module stack are arranged in an array for serial connection. Is installed in the module case and the electrode case of the unit modules in the module case, one or more bus bars for serial connection of the unit modules are mounted in the exposed state to perform welding from the outside And an electrically insulating cover surrounding the assembly and the bus bar assembly. It relates to a battery module to be gong.

BACKGROUND ART [0002] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. The secondary battery is also attracting attention as a power source for an electric vehicle (EV) and a hybrid electric vehicle (HEV), which are proposed as solutions for the air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels .

In a small mobile device, one or two or more battery cells are used per device, while a middle- or large-sized battery module such as an automobile is used as a middle- or large-sized battery module in which a plurality of battery cells are electrically connected due to the necessity of a large-

Since the middle- or large-sized battery module is preferably manufactured in a small size and weight, a prismatic battery, a pouch-shaped battery, and the like, which can be charged with a high degree of integration and have a small weight to capacity ratio, are mainly used as the battery cells of the middle- or large-sized battery modules. Particularly, a pouch-shaped battery using an aluminum laminate sheet or the like as an exterior member has recently attracted a great deal of attention due to its advantages such as a small weight and a low manufacturing cost.

However, since the external member itself is not excellent in mechanical rigidity, in order to manufacture a battery module having a stable structure, generally, battery cells (unit cells) are attached to a pack case such as a cartridge to manufacture a battery module . However, since a mounting space is limited in a device or a vehicle in which a middle- or large-sized battery module is mounted, when the size of the battery module is increased due to the use of a pack case such as a cartridge, a problem of low space utilization is caused. Further, the low mechanical rigidity of the battery cell is caused by the repeated expansion and contraction of the battery cell during charging and discharging, resulting in a case where the heat-welded portion is separated.

Therefore, in order to solve this problem, the present applicant is a Korean Patent Application No. 2006-45444, the battery module including the plate-shaped battery cells, the electrode terminals are formed on the top and bottom, respectively, the electrode terminals are mutually in series Two or more battery cells connected to each other and bent at the connection part of the electrode terminals to form a stacked structure, and a pair of high strength cells which are mutually coupled to cover the entire outer surface of the battery cell stack except for the electrode terminal part. A battery module composed of a cover has been presented.

According to this technique, in the process of assembling the battery module, the two pouch-shaped battery cells are mutually coupled by ultrasonic welding in a state in which the electrode terminals thereof are serially aligned in the longitudinal direction so as to be adjacent to each other continuously. Then, two battery cells combined with electrode terminals are folded so as to face each other to form a battery cell stack, and then a unit cover is manufactured to manufacture a unit battery module, and electrode terminals are connected to produce a medium-large battery module.

However, as described above, in the process of connecting the electrode terminal and the electrode terminal or the electrode terminal and the electrode tab between the unit battery module, before welding the battery module to the pack housing, welding of the electrode terminal and the electrode tab is generally performed by ultrasonic welding. After mounting and connecting the electrode terminal is mounted in the pack housing. Therefore, not only the assembly process is complicated, but there is a problem that an internal short circuit may occur due to the impact generated during the assembly process being transmitted to the electrode terminal.

In addition, since the positive electrode terminal and the negative electrode terminal of the battery module is made of different materials, the welding bonding force between the terminals tends to be inferior when welding them to each other. There is a problem that a short circuit may occur due to separation of the welded portion at the time of application.

Therefore, there is a great need for a technique that can easily assemble a middle- or large-sized battery pack, improve welding reliability, and fundamentally secure safety while solving the above problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

Specifically, an object of the present invention, by configuring the battery module in a specific structure and arrangement of the battery cells connected in parallel for high capacity and connected in series using a specific bus bar assembly, the overall compact, stable, easy to assemble Rather, it provides a battery module and a battery pack including the same that can be configured by selecting a variety of battery cells as needed in the manufacturing process.

According to an aspect of the present invention,

A unit module stack in which two or more battery cells are mounted on the cell cover in parallel with each other and the unit modules protruding out of the cell cover with the electrode terminal connecting portions of the battery cells vertically bent are stacked in two or more numbers. ;

A module case in which the unit modules of the unit module stack are mounted in an array for serial connection and the electrode terminals of the unit modules are opened;

A bus bar assembly mounted to the electrode terminal portions of the unit modules in the module case, wherein at least one bus bar for serial connection of the unit modules is exposed to be welded from the outside; And

An electrically insulating cover surrounding the bus bar assembly;

As shown in FIG.

Accordingly, the battery module and the battery pack including the same according to the present invention have a compact and stable structure as a whole, easy to assemble, and various battery cells selected as necessary in the manufacturing process. It can work. In addition, welding between the same materials is performed in parallel connection between battery cells, thereby providing improved welding reliability.

The battery cell is preferably a plate-shaped battery cell so as to provide a high deposition rate in a limited space. For example, the battery cell may have a structure in which an electrode assembly is embedded in a battery case of a laminate sheet.

Specifically, the battery cell is a pouch-shaped secondary battery in which an electrode assembly having a positive electrode / separator / negative electrode structure is sealed inside a battery case together with an electrolyte solution, and is a plate-shaped battery cell having a substantially rectangular parallelepiped structure with a thin width. The pouch type secondary battery is generally composed of a pouch-type battery case, and the battery case includes an outer covering layer made of a polymer resin having excellent durability; A barrier layer made of a metal material exhibiting barrier properties against moisture, air, and the like; And an inner sealant layer composed of a polymer resin that can be thermally fused, are laminated in this order.

In one preferred embodiment, the battery cells of the unit module are connected in parallel with the electrode terminals directly coupled to each other, and the electrode terminal connection portion is vertically bent to provide a welding surface contacting the bus bar of the bus bar assembly .

Preferably, the battery cell has a structure in which a positive electrode terminal and a negative electrode terminal are formed together at one end thereof, and the unit modules are alternately arranged such that the positive electrode terminal and the negative electrode terminal are adjacent to each other between adjacent unit modules. It may be made of a stacked structure.

Such an alternating arrangement is highly desirable because it does not require the use of a long length connecting member for series connection between the unit modules.

The module case may vary, and preferably, may have a frame structure surrounding the outer circumferential surface of the unit module stack.

In the above structure, the outer surface of the module case may be a structure in which at least one coupling portion for mounting the battery module to the device or pack case is formed.

Preferably, the coupling portion may be configured to protrude from the outer surface of the module case in the vertical direction and have a structure in which the indented groove is formed along the vertical center axis. Of course, the shape and number of the grooves is not particularly limited.

In one preferred embodiment, the bus bar assembly comprises: a rectangular assembly body mounted to a module case and made of an electrically insulating material; And one or more bus bars mounted on the rectangular body in a state where the front and rear surfaces are open.

In one specific example, the bus bar assembly includes a plurality of bus bars, and the bus bars may be formed of a metal plate having both ends coupled to the assembly body, and at one end of the bus bar for voltage detection. It may have a structure in which a detection terminal is additionally included.

In such a structure, the bus bars constituting the external input / output terminals among the bus bars may have a structure including an external input / output terminal unit coupled to the assembly main body with one end extended.

The external input / output terminal portion may be, for example, a structure coupled to the assembly body by bolts, but is not particularly limited.

In some cases, the bolt may be coupled to the module case via the assembly body, for example, through a through hole of the assembly body.

On the other hand, the electrical connection of the bus bar to the electrode terminal connection can be achieved by performing welding on the outer surface of the bus bar.

The welding may be, for example, a method achieved by irradiating a laser to the outer surface of the bus bar.

The mounting method of the bus bar assembly to the module case may vary. For example, fasteners protrude from both ends of the bus bar assembly, and a fastening groove corresponding to the fastener is formed in the module case. It may be a structure.

Similarly, the mounting method of the cover to the bus bar assembly may also vary. For example, fasteners protrude from both ends of the cover, and the bus bar assembly is provided with a fastening groove corresponding to the fastener. It can be a structure.

The present invention also provides a battery pack in which at least two battery modules are mounted in a pack case, and a device using the battery module or the battery pack as a power source.

Preferred examples of the device in which the battery pack according to the present invention can be used include an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or a power storage device having a limited mounting space and exposed to frequent vibrations and strong impacts. Can be.

It goes without saying that battery packs used as power sources for automobiles can be manufactured in combination according to a desired output and capacity.

Electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and the like using a battery pack as a power source are known in the art, and a detailed description thereof will be omitted in this specification.

As described above, the battery module according to the present invention constitutes a battery module connected in parallel in a specific structure and arrangement and is connected in series using a specific bus bar assembly, thereby making the overall compact, stable, and easy to assemble. In addition, various battery cells may be selected and configured as needed in the manufacturing process.

1 is an exploded perspective view of a battery module according to an embodiment of the present invention;
2 is a perspective view of a battery module according to an embodiment of the present invention;
3 is a perspective view of a battery pack mounted with a battery module according to the present invention;
4 is a perspective view of a battery cell mounted in a unit module;
5 is an exploded schematic view of FIG. 4;
6 is a perspective view of a unit module with two battery cells according to the present invention;
7 is a perspective view of a unit module stack in which two unit modules are stacked according to the present invention;
8 is a plan view of a battery module according to the present invention;
FIG. 9 is an enlarged view of a portion 'A' of FIG. 7.

Hereinafter, although described with reference to the drawings of the battery pack according to an embodiment of the present invention, this is for easier understanding of the present invention, the scope of the present invention is not limited thereto.

1 is an exploded perspective view schematically showing a battery module according to an embodiment of the present invention, Figure 2 is a perspective view schematically showing a battery module according to an embodiment of the present invention, Figure 3 schematically shows a perspective view of a battery pack mounted with a battery module according to the present invention.

Referring to these drawings, the battery pack 200 includes the battery modules 300, the base plate 110, the front support member 120 and the rear support member 130, the side support member 140, and the plurality of strap members. Field 150 is included.

The battery modules 300 are mounted on the upper surface of the base plate 110, and the front support member 120 and the rear support member 130 are mounted on the front and rear surfaces of the battery modules 300, respectively.

The side support member 140 is coupled to the base plate 110 in a structure surrounding one side of the battery modules 300 forming the outer surface of the battery pack 200 and a portion of the front and rear surfaces of the battery pack 200. .

The plurality of strap members 150 are coupled to the base plate 110 while surrounding the top and both sides of the battery modules 300 for fixing or mounting the positions of the battery modules 300.

In the base plate 110, a through hole 115 into which a fastening screw 205 for fixing the battery module 300 is inserted is formed at a position corresponding to the strap member 150.

The battery module 300 includes a unit module stack 600, a module case 360, a bus bar assembly 350, and an electrically insulating cover 310.

The battery module 300 has a structure in which the unit modules 500 including the plurality of battery cells 10 are stacked up and down, and the unit module 500 includes a plurality of electrically connected battery cells 10. The outer surface of the) is made of a structure wrapped by the cell cover 510. Since the battery cell 10 is wrapped by the cell cover 510 and is not exposed to the outside, the battery cell 10 is represented by a dotted line in the drawing.

The structure of the battery cell 10 will be described in more detail below.

To describe the battery module 300 in more detail, the unit module stack 600 is mounted to the cell cover 510 in a state in which two or more battery cells 10 are connected in parallel to each other, and electrode terminals (not shown). Unit modules 500 protruding to the outside of the cell cover 150 are sequentially stacked.

The module case 360 has a frame structure of which an upper surface and a front surface are open so that the unit module stack 600 may be easily mounted and the electrode terminals (not shown) of the unit modules 500 may be mounted in a protruding state. Consists of

In addition, the module case 360 is provided with a bolt insertion portion 365 and a fastening groove 362 for coupling the bus bar assembly 350, and the mounting on the base plate 110 on the outer side of the module case 360. Two coupling parts 363 are formed.

Specifically, the engaging portion 363 protrudes from the outer surface of the module case 360 in the vertical direction, and the indented groove 361 is formed along the upper and lower central axes, so that the strap member (3) is provided in the indented groove 361. 150 is inserted and mounted to the base plate 110. Sides of the indented grooves 361 are formed with a plurality of ribs 366 pointing to the engaging portion 363.

The bus bar assembly 350 is mounted on one surface of the module case 360, and bus bars 351 for connecting the electrode terminals of the unit modules 500 in series are mounted.

The bus bars 351 are provided with a detection terminal 352 for voltage detection in one direction from one end thereof. Among the bus bars 351, one end thereof extends in the length direction of the bus bars 351. The external input / output terminal portion 353 mounted on the main body of the bus bar assembly 350 in a state is included.

In addition, a fastening groove 355 is formed in the bus bar assembly 351 to be coupled to the electrically insulating cover 310, and a fastener 354 is formed to be coupled to the module case 360.

As such, when the bus bar assembly 351 is mounted on the front surface of the module case 360, the bus bar 351 contacts the electrode terminals of the unit modules 500, and thus, from the front surface of the bus bar assembly 351. The laser beam is irradiated onto the bus bar 351 to facilitate welding.

The electrically insulating cover 310 is mounted to surround a portion where the bus bar 351 of the bus bar assembly 350 is formed.

In addition, the cover 310 is formed of a plastic material to insulate the internal parts and the outside, and a plurality of fasteners 311 are formed for coupling with the bus bar assembly 351.

The module case 360, the bus bar assembly 350, and the cover 310 of the battery module 300 have fastening grooves 355 formed at the bus bar assembly 350 with fasteners 311 formed at the cover 310. The fasteners 354 inserted into the bus bar assembly 350 are inserted into the fastening grooves 362 formed in the module case 360 and are easily fastened to each other.

In addition, the external input / output terminal 353 is inserted into the bolt insertion portion 365 formed in the module case 360 by bolts to complete the coupling.

4 is a perspective view schematically showing one exemplary battery cell mounted on a unit module of the present invention, and FIG. 5 is an exploded schematic view of FIG. 4.

Referring to these drawings, the plate-shaped battery cell 10, inside the pouch-shaped battery case 20, the electrode assembly consisting of a positive electrode, a negative electrode and a separator disposed therebetween its positive and negative electrode tabs (220, 230) Two electrode terminals 222 and 232 electrically connected to each other are configured to be sealed to be exposed to the outside.

The battery case 100 includes a case body 15 including a recess 14 having a concave shape in which the electrode assembly 210 may be seated, and a cover 13 integrally connected to the body 15. have.

In the electrode assembly 210 having a stack type or stack / fold type structure, a plurality of positive electrode tabs 220 and a plurality of negative electrode tabs 230 are fused to each other and coupled to the electrode terminals 11 and 12. In addition, when the surplus portion 144 and the cover 13 of the case body 15 are heat-sealed by the heat welder, the short between the heat welder and the electrode terminals 222 and 232 is prevented from occurring and the electrode terminal 222 is prevented. The insulating film 240 is attached to the upper and lower surfaces of the electrode terminals 222 and 232 to secure the sealing property between the battery pack 232 and the battery case 20.

The case body 15 and the lid 13 are composed of an outer resin layer 16, a barrier metal layer 17, and an inner resin layer 18, and the inner resin layer 18 is an outer surface of the case body 15. And heat and pressure from a heat fusion machine (not shown) applied to the outer surface of the cover 13 can be tightly fixed.

When the electrode assembly 210 impregnated with the electrolyte is seated on the accommodating part 12, the sealing part is formed by heat-sealing the contact portion between the excess part 144 of the case body 15 and the cover 13.

6 schematically shows a perspective view of a unit module in which two battery cells are built according to the present invention, and FIG. 7 schematically illustrates a perspective view of a unit module stack in which two unit modules according to the present invention are stacked. 8 is a plan view of a battery module according to the present invention, and FIG. 9 is an enlarged view of a portion 'A' of FIG. 7.

Referring to these drawings, the unit module 500 includes two stacked battery cells 10 and a cell cover 510 having a structure surrounding the entire outer surface thereof.

The battery module 300 includes a unit module stack 600 in which a plurality of unit modules 500 are stacked, and the unit modules 500 include electrode terminals 222 and 232 of a built-in battery cell 10. This is connected to each other in series with the outside exposed.

The electrode terminals 222 and 232 of the unit modules 500 are vertically bent to be connected in parallel to each other so that the 'c' shaped electrode terminal connecting portions 550 are formed on the vertical cross sections, and the electrode terminals having the same polarity are the same vertical line. Positioned in parallel to one another.

The electrode terminal connections 550 are vertically bent to provide a welding surface in contact with the bus bar 351 of the bus bar assembly 350. Since the welding surface is electrically connected by laser welding irradiating the laser in a state of being in contact with each other at the outer portion of the bus bar 351, the laser terminal is fixed after fixing the electrode terminal connecting portions 550 to the module case 360. By performing the welding, assembly of the battery module can be easily performed.

The unit modules 500 are interconnected by the bus bar 351 and finally electrically connected to the external input / output terminal 353.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

Claims (21)

A unit module in which two or more battery cells are mounted in a cell cover in a state where they are connected in parallel to each other and the electrode terminal connection portion of the battery cells is protruded outside the cell cover in a vertically bent state, ;
A module case in which the unit modules of the unit module stack are mounted in an array for serial connection and the electrode terminals of the unit modules are opened;
A bus bar assembly mounted to the electrode terminal portions of the unit modules in the module case, wherein at least one bus bar for series connection of the unit modules is exposed to be welded from the outside; And
An electrically insulating cover surrounding the bus bar assembly;
The battery module comprising: The battery module according to claim 1, wherein the battery cell is a plate-shaped battery cell. The battery module according to claim 2, wherein the battery cell has a structure in which an electrode assembly is built in a laminate battery case. The method of claim 1, wherein the battery cells of the unit module are connected in parallel with the electrode terminals directly coupled, the electrode terminal connecting portion is bent vertically to provide a welding surface in contact with the bus bar of the bus bar assembly Battery module. The battery cell of claim 1, wherein the battery cell has a structure in which a positive electrode terminal and a negative electrode terminal are formed together at one end thereof, and the unit modules are alternately arranged such that the positive and negative terminals are adjacent to each other between adjacent unit modules. A battery module, which is laminated in a state. The battery module according to claim 1, wherein the module case has a frame structure surrounding an outer circumferential surface of the unit module stack. The battery module according to claim 1, wherein at least one coupling part for mounting the battery module is formed on the outer surface of the module case. The battery module according to claim 7, wherein the coupling part protrudes from the outer surface of the module case in the vertical direction and has a structure in which an indented groove is formed along the vertical center axis. The assembly of claim 1, wherein the bus bar assembly comprises: a rectangular assembly body mounted on a module case and electrically insulating; And at least one bus bar mounted at the front and rear sides of the rectangular body in an open state. 10. The battery module of claim 9, wherein the bus bar assembly includes a plurality of bus bars, and the bus bar is a metal plate having both ends coupled to the assembly body. The battery module according to claim 10, wherein a detection terminal for voltage detection is added at one end of the bus bar. The battery module according to claim 10, wherein the bus bars constituting the external input / output terminals of the bus bars include an external input / output terminal unit coupled to the assembly main body with one end thereof extended. The battery module according to claim 12, wherein the external input / output terminal is coupled to the assembly body by bolts. The battery module according to claim 13, wherein the bolt is also coupled to the module case. The battery module according to claim 1, wherein the electrical connection of the bus bar to the electrode terminal connection part is achieved by welding the outer surface of the bus bar. The battery module according to claim 15, wherein the welding is achieved by irradiating a laser to an outer surface of the bus bar. The battery module according to claim 1, wherein fasteners protrude from both ends of the bus bar assembly, and fastening grooves corresponding to the fasteners are formed in the module case. The battery module according to claim 1, wherein fasteners protrude from both end portions of the cover, and fastening grooves corresponding to the fasteners are formed in the bus bar assembly. The battery pack according to any one of claims 1 to 18, wherein at least two battery modules are mounted on the pack case. A device comprising the battery module according to claim 1 or the battery pack according to claim 19 as a power source. The device of claim 20, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

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