KR20090095954A - Secondary Battery Pack of Structure Based upon Improved Productability - Google Patents

Abstract

A secondary battery pack is provided to enhance the assembling workability of a battery pack, to reduce the number of process and to make the automation of the process be possible, thereby improving productivity. A secondary battery pack comprises a battery cell(200) formed at the upper end of a first electrode terminal and a second electrode terminal; a protection circuit module comprising a protection circuit board and a connecting terminal; an electrode terminal connecting member which comprises a hollow insulating mold block and a connecting part and is combined to the connecting terminal of the protection circuit module; and an insulating cap(501) which is combined to the upper end of the battery cell with surrounding the protection circuit module and the electrode terminal connecting member, and has apertures(550,560) formed at the both side ends, and where side caps(600,620) sealing the apertures are connected integrally.

Description

Secondary Battery Pack of Structure Based upon Improved Productability}

The present invention relates to a secondary battery pack having an improved manufacturing processability, and more particularly, an electrode assembly is sealed in an inside of a battery case together with an electrolyte solution, and a first electrode terminal and a second electrode terminal are formed on an upper end of the battery case. A battery cell formed in the battery cell, a protection circuit module (PCM) formed of a protection circuit board (PCB) and a connection terminal, an electrode terminal connection member mounted on an upper surface of the battery cell and coupled to the connection terminal of the PCM, and a PCM and electrode terminal connection Coupled to the upper end of the battery cell surrounding the member, the opening for welding the side of the connecting terminal and the coupling portion of the connection from the outside is formed at both ends, and the side cap for sealing the opening after completing the welding is integral It relates to a secondary battery pack including an insulating cap connected to.

Due to the development of technology and increasing demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, lithium secondary batteries with high energy density, high operating voltage, and excellent storage and life characteristics are not only various mobile devices but also various electronic products. It is widely used as an energy source.

Secondary batteries are classified into roughly cylindrical cells, square cells, and pouch cells according to external and internal structural features. Among them, rectangular batteries and pouch cells having a small width to length are particularly noticeable. I am getting it.

In addition, secondary batteries are attracting attention as energy sources such as electric vehicles and hybrid electric vehicles, which are proposed as a way to solve air pollution of conventional gasoline and diesel vehicles using fossil fuel. Therefore, the type of applications using the secondary battery has been very diversified due to the advantages of the secondary battery, and it is expected that the secondary battery will be applied to many fields and products in the future.

However, the lithium secondary battery contains various combustible materials, and there is a danger of overheating or explosion due to overcharging, overcurrent, other physical external impact, etc., and thus has a serious safety drawback. Accordingly, a lithium secondary battery is mounted with a protection circuit module (PCM) connected to a battery cell capable of effectively controlling abnormal states such as overcharge and overcurrent.

In general, a PCM is composed of a structure in which a field effect transistor (FET), a voltage detector, a capacitor, and the like are coupled to a printed circuit board (PCB), and the safety devices including the PCM are electrode terminals. Maintain electrical connection with the battery while maintaining electrical insulation from other parts of the battery cell. Therefore, in order to form the connection and insulation structure as described above, welding, soldering, etc. for electrically connecting the PCM to the battery cell must be repeatedly performed, and a plurality of insulating mounting members are required. It has a complicated problem.

In particular, when the electrode terminal connecting member is used to electrically connect the connecting terminal of the PCM and the electrode terminal of the battery cell, the side of the coupling portion of the connecting terminal of the PCM and the connecting terminal of the electrode terminal connecting member is welded from the outside to be joined together. In order to keep the part insulated from the outside, a side cap for separately sealing and insulating the joint part is required. However, the process of attaching such side caps to the weld joint is a process requiring delicate work in a limited space, and therefore requires a lot of work time, and greatly reduces the manufacturing processability and productivity of the battery pack.

Therefore, the research on the technique of assembling the upper assembly of the battery pack in a simple and easy way is actively progressing. For example, Korean Patent Application Publication No. 2007-0071245 has a bare cell, a body part attached to one side of the bare cell, and two electrical terminals connected to two electrode terminals of the bare cell. Disclosed is a secondary battery having a formed protection circuit board portion.

However, since the protection circuit board portion must be formed on one side of the bare cell, there is an inconvenience in that the connection terminal of the protection circuit board electrically connected to the electrode terminal on the top of the bare cell must be separately formed on the side, and the bare cell. Since the structure of the cap to surround the protective circuit board formed on one side of the need to be formed again, the manufacturing process is complicated, there is a problem that the productivity is lowered.

In addition, Korean Patent Application Laid-Open No. 2006-0085193 is a box-type or plate-shaped battery pack, which includes a hard outer jacket member having first and second openings formed at both ends, and a box-type or having an electrode terminal embedded in the outer jacket member. A plate-shaped battery element, a cover molded of resin and fitted into the first opening, a circuit board connected to the electrode terminal lead and embedded in the cover, the at least one electrode terminal lead extending from the first opening, and the cover A battery pack having recesses on both ends of one longer side, the outer jacket member having a cutout exposing at least one recess of the cover, and the outer jacket member and at least one longer side of the cover being heat bonded Is starting.

However, the above technique requires complicated structural parts that are not easy to manufacture, such as a cover having a recess formed therein and a cutout that exposes the recess of the cover, and an outer jacket member having a circuit board embedded therein. Since at least one longer side must be subjected to a process such as thermal bonding, there is a problem that the degree of improvement in manufacturing processability of the battery pack does not reach a desired level.

Therefore, there is a high need for a technology that can solve the problems of the prior art as described above and improve the manufacturing processability and productivity of the battery pack by a simple and easy assembly process.

The present invention aims to solve the above-mentioned problems of the prior art and technical problems that have been requested from the past.

Specifically, an object of the present invention is to change the structure of the various members mounted on the battery cell, to reduce the assembly process of the battery pack, to enable the automation of the process, the secondary battery of the structure that can greatly improve the productivity Is to provide a pack.

Secondary battery pack according to the present invention for achieving this object,

A battery cell in which an electrode assembly having a cathode / separation membrane / cathode structure is sealed inside the battery case together with an electrolyte solution, and the first electrode terminal and the second electrode terminal are formed on an upper end of the battery case;

A protection circuit module (PCM) including a protection circuit board (PCB) having a protection circuit formed thereon, and connection terminals mounted on both bottom surfaces of the PCB in a vertical cross-section with a '-' shape;

An electrode terminal connecting member comprising a hollow insulating mold block and connecting parts mounted on both sides of the insulating mold block, and mounted on an upper surface of the battery cell and coupled to the connecting terminal of the PCM; And

It is coupled to the upper end of the battery cell surrounding the PCM and the electrode terminal connecting member, and openings for welding the side of the coupling terminal and the coupling portion from the outside are formed at both ends, and the opening is completed after welding is completed. An insulating cap having a sealed side cap integrally connected;

It is configured to include.

That is, the secondary battery pack according to the present invention has a side surface of the coupling portion of the PCM (specifically, the connection terminal of the PCM) and the electrode terminal connection member (specifically, the connection portion of the electrode terminal connection member). The side cap sealing the opening after welding from the outside through is integrally connected to both ends of the insulating cap, so that the side cap is insulated as compared to the structure of the rechargeable battery pack in which the conventional insulating cap and the side cap are separated. Since it can be easily inserted into the opening of, the workability can be improved and the manufacturing productivity of the battery pack can be greatly improved.

On the other hand, the present applicant is a secondary battery pack having a structure that simplified the assembly process and the members mounted on the top of the battery cell in Korea Patent Application No. 2007-0105189, the opening is formed in the center of the PCM, connection member The secondary battery pack has a structure in which the structure is in close contact with the lower surface of the opening, and can connect the connection member and the battery cell electrode terminal to each other by welding using the opening.

However, in the secondary battery pack having the above structure, since the opening structure of the PCM has to be formed at a position corresponding to the electrode terminal of the battery cell, external input / output terminals have a limitation in not being located at the central portion of the PCM having the opening.

In contrast, the secondary battery pack according to the present invention has a structure in which no opening is formed in the PCM, while minimizing the number of members mounted on the top of the battery cell and simplifying the assembly process. The location of the input / output terminals is also not limited as described above. Therefore, the external input / output terminals on the upper surface of the PCM may be formed at a desired position according to the specification of the device in which the secondary battery pack is used.

The unitary structure of the side cap and the insulating cap may be implemented in various ways, for example, the side cap may be connected to the insulating cap in a hinge structure.

The side cap, as mentioned above, consists of a structure that is integrally connected to both ends of the insulating cap, it is possible to easily and easily configure the assembly process of the top of the battery pack, and to enable the automation of the process, For example, the insulating cap and the side cap of the structure may be integrally formed during insert injection molding.

In one preferred example, an insulating tape may be attached to the bottom surface of the insulating cap at a size including at least the bottom surface of the insulating cap. For example, the insulating tape may have an adhesive material coated on the upper surface thereof, and a release paper may be attached to the upper surface of the adhesive material.

Considering that the height of the insulating tape should be of an appropriate size including the bottom surface of the insulating cap, for example, it may be made from 50 to 150% based on the height of the insulating cap.

Since the battery case is required for ease of processing and a certain level or more of mechanical strength, the battery case may be a metal can, preferably an aluminum can or a stainless steel can.

The electrode terminals formed on the top of the battery case may be variously applied regardless of the type and shape of the battery cell. For example, in the case of a square battery cell, the first electrode terminal protrudes from the center of the battery cell. The negative electrode terminal is inserted into the lower portion of the hollow portion of the insulating mold block, the second electrode terminal may be composed of a positive electrode terminal forming the top surface of the battery cell case.

The connecting portion of the electrode terminal connecting member includes a connecting portion A coupled to the first electrode terminal of the battery cell, and a connecting portion B coupled to the second electrode terminal of the battery cell. The connecting portion A and the connecting portion B One end of the c) is bent upward in a '-' shape on the vertical cross section, and can be easily electrically coupled to a connection terminal mounted in a '-' shape on the vertical cross-section on both bottom surfaces of the PCB.

Specifically, as mentioned above, after the electrode terminal connecting member, the PCM, and the insulating cap are sequentially mounted on the top of the battery cell, the connecting portion of the PCM connecting terminal and the electrode terminal connecting member is opened through the opening of the insulating cap. The overlapping portions can be easily joined by side welding. For reference, side welding means performing welding in the lateral direction.

The connection portion A is not particularly limited as long as it is a material or structure capable of electrically connecting the connection terminal of the PCM and the electrode terminal of the battery cell while maintaining an insulation state with the upper end of the battery cell. A) is made of a metal plate, a part of the metal plate may be a structure embedded in the insulating mold block. The connection part B may further include a function of electrically connecting the connection terminal of the PCM and the electrode terminal of the battery cell to further improve the safety of the battery pack by the structure of the PTC device. For example, the connection portion B has a structure of a PTC element including a PTC body, a PCM coupling portion coupled to an upper surface of the PTC body, and a battery cell coupling portion coupled to a lower surface of the PTC body. Part of the battery cell coupling portion may be a structure embedded in the insulating mold block.

Therefore, when the temperature of the battery pack rises rapidly due to an internal short circuit or the like, the connection portion B coupled with the PTC element serves to block the current flow between the battery cell and the PCM, thereby improving the safety of the battery pack. .

The PTC body may have a variety of structures, for example, may be a structure formed by bonding a metal foil to the upper and lower surfaces of the PTC material layer made of a PTC polymer composite, respectively.

The PCM coupler and the battery cell coupler are not particularly limited as long as they have a material having excellent conductivity. For example, the PCM coupler and the battery cell coupler may be made of a nickel plate. Preferably, the battery cell coupling portion itself may be a structure consisting of a metal clad structure for facilitating the coupling with the battery cell second electrode terminal.

On the other hand, in the connecting portion of the electrode terminal connecting member, the metal plate and the battery cell coupling portion may be formed integrally during the molding of the insulating mold block, for example, when formed simultaneously with the insulating mold block by the insert injection molding method, It is preferable because no additional process for mounting the metal plate and the battery cell joint to the insulating mold is necessary. Therefore, the metal plate and the battery cell coupling portion may be manufactured to have a buried structure during insert injection molding of the insulating mold block.

In some cases, an insulator for insulating the upper surface of the battery cell is additionally mounted on the lower surface of one end portion of the connecting portion A, so that the step of attaching the insulating tape for insulating the connecting portion to the upper surface of the battery cell is omitted. Can be.

In addition, an insulating member may be additionally mounted at one lower end of the connection part B. For example, such an insulating member has a structure in which an insulating material for insulating the upper surface and the lower surface of one end portion of the connection portion B is applied or a predetermined insulator is coupled to the upper surface and the lower surface of the one end portion. By constructing the structure in which the insulating tape is wrapped, mutual insulation between the battery cell upper surface and the connection portion B can be more stably achieved.

Coupling of the electrode terminal connecting member to the upper surface of the battery case (specifically, the coupling of the insulating mold block of the electrode terminal connecting member) in consideration of the manufacturing processability and stable mounting structure of the battery pack, for example, bonding (Bonding) Or by welding.

On the other hand, it is preferable that the outer surface of the battery case is attached to the outer film to ensure the electrical insulation state and display the product information.

The battery cell may be variously applied regardless of its type and appearance, and may be preferably a rectangular lithium secondary battery cell.

Hereinafter, although described with reference to the drawings 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 of a rechargeable battery pack according to the prior art.

Referring to FIG. 1, the secondary battery pack 100 is mounted on the battery cell 200 and the upper surface of the battery cell 200 in which the electrode assembly is sealed inside the battery case together with the electrolyte solution. It is mounted on the upper surface of the electrode terminal connecting member 400, the electrode terminal connecting member 400 for electrically connecting the connection terminals 310 and 320 and the electrode terminals 220 and 240 of the battery cell 200, and overcharge An insulating top cap 500 coupled to the upper end of the battery cell 200 while covering the electrode terminal connecting member 400 in a state where the PCM 300 and the PCM 300 are mounted to effectively control abnormal conditions such as the battery. It consists of a structure including an insulating lower cap 510 is coupled to the lower end of the cell 200, and an outer film 520 attached to surround the outer surface of the case of the battery cell 200.

The upper surface 240 of the battery cell 200 is formed with a negative electrode terminal 220 protruding upward in an insulated state from the battery case, and the remaining portion except for the negative electrode terminal 220 forms a positive electrode terminal. In addition, a metal clad 241 made of an aluminum-nickel alloy is attached to one side of the remaining portions so that the bonding force between the connection portion B 420 of the electrode terminal connecting member 400 and the positive electrode terminal portion is improved, and the electrode terminal is connected to the other side. An insulating tape 242 is attached for insulation from the member 400.

The electrode terminal connecting member 400 is mounted on the top surface 240 of the battery cell 200 by an adhesive method and is coupled to each other. The protruding negative electrode 220 of the battery cell 200 is inserted into the lower portion of the connection part B 420. The opening 430 is formed at the center portion so as to be coupled to the center.

The insulating upper cap 500 wraps the electrode terminal connecting member 400 in a state where the electrode terminal connecting member 400 and the PCM 300 are sequentially mounted on the top of the battery cell 200. It is coupled to the top, extends downward to a predetermined length so as to surround the upper outer surface of the battery cell 200, the A / S label 502 is attached to one side of the upper surface.

In addition, an opening 550 for welding the side surfaces of the connection portions 310 and 320 of the PCM 300 and the coupling portions 410 and 420 of the electrode terminal connecting member 400 from the outside may include an insulating upper cap ( It is formed at both ends of 500).

After welding the overlapping portions of the connecting terminals 310 and 320 of the PCM 300 and the connecting portions 410 and 420 of the electrode terminal connecting member 400 laterally, the side for inserting through the opening 550. Caps 600 and 610 are configured separately.

The outer film 520 made of a heat-shrinkable material is manufactured in the form of a tube, wrapped around the battery cell 200, and then applied with heat to be adhered to the battery cell 200 case surface while being contracted.

2 is a perspective view schematically showing a state in which the insulating cap according to an embodiment of the present invention mounted on the top of the battery cell as a partial perspective view.

Referring to FIG. 2, the insulating cap 501 is coupled to an upper end of the battery cell 200, openings 550 and 560 are formed at both ends thereof, and side caps 600 and 620 are integrally formed. It is.

The side caps 600 and 620 are hingedly connected to the insulating cap 501 and connect the connection terminal (not shown) of the PCM and the electrode terminal connecting member (not shown) through the openings 550 and 560. And welds to the coupling portion, and then bends downward to seal the openings 550 and 560. Therefore, since the side caps 600 and 620 are integrally formed in the insulating cap 501, the operation of closing the openings 550 and 560 after welding of the corresponding site can be performed very easily.

3 is a perspective view schematically showing an electrode terminal connecting member used in a battery pack according to an embodiment of the present invention, Figure 4 is a vertical cross-sectional view of the electrode terminal connecting member, PCM and the top of the battery cell of FIG. Schematics are shown.

Referring to these drawings, the electrode terminal connecting member 401 includes a hollow insulating mold block 450 and a connecting portion A 410 and a connecting portion B 420 mounted on both sides of the insulating mold block 450. . The connection parts 410 and 420 are formed to be partially embedded in the insert injection molding of the insulating mold block 450, and one end portions 412 and 422 are bent upward in a '-' shape on a vertical section. .

A portion of the connection portion A 410 made of a metal plate is embedded in the insulating mold block 450, and an insulator 470 for insulating the upper surface of the battery cell 200 is formed at one end of the connection portion A 410. It is mounted on. The insulator 470 may be integrally formed with the insulating mold block 450 in a state of passing through a portion of the connection portion A 410.

The connection portion B 420 has a structure of the PTC body 4202, the PCM coupling portion 4204 coupled to the top surface of the PTC body 4202, and the battery cell coupling portion 4206 coupled to the bottom surface of the PTC body 4202. A part of the battery cell coupling part 4206 is embedded in the insulating mold block 450, and the insulating member 461 surrounds one end of the connection part B 420. The insulating member 461 may also be formed to have a structure surrounding the upper and lower portions of the PCM coupling portion 4204.

The battery cell coupling part 4206 has a metal clad structure to facilitate coupling with the positive electrode terminal 240 of the battery cell 200.

The negative electrode terminal 220 of the battery cell 200 is inserted from the bottom into the opening 430 of the connection portion A 410 and coupled to the metal plate 460 by welding, and the positive electrode terminal 240 of the battery cell 200. Is coupled to the battery cell coupling portion 4206 of the connection portion B (420) by welding.

In addition, the PCM 300 is a vertical cross-section of the printed circuit board 340 on which the plurality of elements 330 are mounted on the protection circuit and the lower surface of both sides of the printed circuit board 340 in a state connected to the protection circuit. It consists of connecting terminals 310 and 320 that are mounted in the shape of a child.

FIG. 5 is a vertical cross-sectional schematic diagram of the insulating cap of FIG. 2, and FIG. 6 is a vertical cross-sectional schematic diagram showing a state where an insulating tape is attached to the bottom surface of the insulating cap of FIG. 2.

First, referring to FIG. 5, side caps 510 integrally formed with the insulating cap 501 during insert injection molding are continuously connected to both ends of the insulating cap 501 in a hinge structure, as mentioned above. Therefore, it is possible to reduce the number of battery pack manufacturing processes, to automate the process, and ultimately to improve assembly productivity. The insulating cap 501 is mounted and coupled to a battery cell (not shown) in a form of wrapping the PCM 300.

Referring next to FIG. 6, the insulating tape 700 includes a bottom surface 502 of the insulating cap 501, with a size h of approximately 75% based on the height H of the insulating cap 501. The lower outer surface of the furnace insulating cap 501 is attached to the upper outer surface of the battery cell 200.

Release paper (not shown) is attached to the insulating tape 700 in the direction of the insulating cap 501, and after the insulating cap 501 is attached to the battery cell 200, the release paper is removed to remove the insulating tape 700. By attaching to the battery cell 200, the coupling process of the insulating cap 501 to the battery cell 200 can be easily performed.

As described above, the secondary battery pack according to the present invention can improve the assembly workability of the battery pack and reduce the number of processes, and the process can be automated, thereby greatly improving the manufacturing processability and productivity of the battery pack. It can be effective.

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.

1 is an exploded perspective view of a rechargeable battery pack according to the prior art;

2 is a perspective view showing a state in which the insulating cap is mounted on the top of the battery cell in a battery pack according to an embodiment of the present invention in a partial perspective view;

3 is a perspective view of an electrode terminal connecting member used in a battery pack according to an embodiment of the present invention;

Figure 4 is a vertical cross-sectional schematic diagram of the electrode terminal connecting member, PCM, and the battery cell top of Figure 3;

5 is a vertical cross-sectional schematic diagram of the insulating cap of FIG. 2;

It is a vertical cross-sectional schematic diagram which shows the state in which the insulating tape was affixed on the lower surface of the insulating cap of FIG.

Claims (17)

A battery cell in which an electrode assembly having a cathode / separation membrane / cathode structure is sealed inside the battery case together with an electrolyte solution, and the first electrode terminal and the second electrode terminal are formed on an upper end of the battery case; A protection circuit module (PCM) including a protection circuit board (PCB) having a protection circuit formed thereon, and connection terminals mounted on both bottom surfaces of the PCB in a vertical cross-section with a '-' shape; An electrode terminal connecting member comprising a hollow insulating mold block and connecting parts mounted on both sides of the insulating mold block, and mounted on an upper surface of the battery cell and coupled to the connecting terminal of the PCM; And It is coupled to the upper end of the battery cell surrounding the PCM and the electrode terminal connecting member, and openings for welding the side of the coupling terminal and the coupling portion from the outside are formed at both ends, and the opening is completed after welding is completed. An insulating cap having a sealed side cap integrally connected; Secondary battery pack comprising a. The secondary battery pack as claimed in claim 1, wherein the side cap is connected to the insulating cap in a hinge structure. The secondary battery pack of claim 1, wherein the insulating cap and the side cap are integrally formed by insert injection molding. The secondary battery pack according to claim 1, wherein an insulating tape is attached to a lower end surface of the insulating cap at least including a lower end surface of the insulating cap. The secondary battery pack according to claim 4, wherein the height of the insulating tape is 50 to 150% based on the height of the insulating cap. The secondary battery pack as claimed in claim 1, wherein the battery case is a metal can. The secondary battery pack of claim 1, wherein the first electrode terminal of the battery cell is a negative electrode terminal and the second electrode terminal is a positive electrode terminal. According to claim 1, wherein the connecting portion of the electrode terminal connecting member comprises a connecting portion (A) coupled to the first electrode terminal of the battery cell, and a connecting portion (B) coupled to the second electrode terminal of the battery cell, A) and one end portion of the connection portion (B) is a secondary battery pack, characterized in that the vertical bent upward in the 'b' shape on the cross-section. The secondary battery pack according to claim 8, wherein the connection portion (A) is made of a metal plate, and a part of the metal plate is embedded in the insulating mold block. 9. The PTC device according to claim 8, wherein the connection portion B has a structure of a PTC element including a PTC body, a PCM coupling portion coupled to an upper surface of the PTC body, and a battery cell coupling portion coupled to a lower surface of the PTC body. And a part of the battery cell coupling part is embedded in the insulating mold block. The secondary battery pack according to claim 10, wherein the PTC body is formed by bonding metal foils to upper and lower surfaces of the PTC material layer made of the PTC polymer composite, respectively. The secondary battery pack according to claim 10, wherein the PCM coupling part and the battery cell coupling part are each made of a metal plate. The secondary battery pack according to claim 9 or 10, wherein a part of the metal plate and the battery cell coupling part is buried in the insert injection molding of the insulating mold block. The secondary battery pack according to claim 8, wherein an insulator is additionally mounted on the lower surface of one end portion of the connection portion (A). The secondary battery pack according to claim 8, wherein an insulating member is further mounted on one lower end of the connection portion (B). The secondary battery pack according to claim 1, wherein the coupling of the electrode terminal connecting member to the top surface of the battery case is achieved by bonding or welding. The secondary battery pack as claimed in claim 1, wherein the battery cell is a rectangular lithium secondary battery cell.

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