KR100882491B1 - Metal Plate as Electrical Connecting Member and Battery Pack Prepared Using The Same - Google Patents

Abstract

A member for electrically connecting a plurality of batteries and additionally connecting a protection circuit to the connection portion, comprising a plate body for welding with an electrode terminal and a connection portion protruding to an outer surface of the body for soldering of the protection circuit. The surface of the connection portion is provided with a metal plate is formed with fine irregularities so that the flow of the molten solder paste can be suppressed. The metal plate according to the present invention can prevent short circuits that may occur when molten solder paste flows out of the plate and contacts the surface of the battery cell during soldering, and further enhances the bonding force between the plate body and the protection circuit. Whenever the design is changed, a variety of battery packs may be manufactured by selecting and selecting metal plates having a specific structure without having to newly design a shape of the connection member so as to conform thereto.

Description

Metal plate as a connecting member and a battery pack manufactured using the same {Metal Plate as Electrical Connecting Member and Battery Pack Prepared Using The Same}

1 is an exploded view showing a coupling manner of batteries electrically connected by a metal plate as a connecting member;

2 is a schematic view of a battery pack with a metal plate and a protection circuit connected;

3 is a schematic diagram of a metal plate according to a first embodiment of the present invention;

4 is a schematic diagram of a metal plate according to a second embodiment of the present invention;

5 is a schematic diagram of a metal plate according to a third embodiment of the present invention;

6 is a partial schematic view of a core pack of 2P-4S linear structure manufactured using the metal plate according to the present invention.

The present invention relates to a metal plate which is a member used for electrical connection of batteries, and more particularly, to a member for electrically connecting a plurality of batteries and additionally connecting a protection circuit to the connection portion. A plate body for welding and a connection portion protruding to the outer surface of the main body for soldering (Soldering) of the protection circuit, the surface of the connection portion is a metal with fine irregularities formed to suppress the flow of the molten solder paste Provide the plate.

As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing.

The secondary battery may be used in the form of a single battery, or in the form of a battery pack in which a plurality of unit cells are electrically connected, depending on the type of external device in which the secondary battery is used. For example, a small device such as a mobile phone can operate for a predetermined period of time with the output and capacity of one battery, while a medium or large size such as a notebook computer, a portable DVD, a small PC, an electric vehicle, a hybrid electric vehicle, or the like. Large devices require the use of battery packs due to power and capacity issues.

Such a battery pack is manufactured by connecting a protection circuit or the like to a core pack in which a plurality of unit cells are arranged in series and / or in parallel. In the case of using a square or pouch type battery as a unit cell, the wide surfaces thereof may be stacked to face each other, and then the electrode terminals may be easily connected by connecting members such as bus bars. Therefore, in the case of manufacturing a three-dimensional battery pack having a hexahedral structure, a square or pouch type battery is advantageous as a unit cell.

On the other hand, the cylindrical battery generally has a larger capacitance than the square and pouch cells, but due to the external characteristics of the cylindrical battery is not easy to arrange in a laminated structure. However, when the shape of the battery pack is a linear or plate-like structure as a whole, there is a structural advantage over the square or pouch type.

Therefore, in the case of a notebook computer, a portable DVD, a small PC, and the like, battery packs in which a plurality of cylindrical batteries are connected in parallel and in series are used. As the core pack structure used in such a battery pack, for example, a linear structure of 2P (parallel) -3S (serial), a plate structure of 2P-3S, a linear structure of 2P-4S, a plate structure of 2P-4S, and the like It is used.

The parallel connection structure is achieved by arranging two or more cylindrical cells adjacent in their lateral directions with the electrode terminals oriented in the same direction, and welding them to the connecting member. Such parallel cylindrical cells are also referred to as "banks".

In series connection structure, two or more cylindrical cells are arranged in a lateral direction while two or more cylindrical cells are arranged in a long manner so that electrode terminals of opposite polarities are continuous or the electrode terminals are arranged in opposite directions. Arranged adjacent to each other, the welding is performed by the connecting member.

In the electrical connection of such cylindrical cells, spot welding is generally performed using a thin connecting member (for example, a metal plate) such as a nickel plate.

FIG. 1 is a schematic view of a battery pack having a plate-like structure of 2P-3S in a state in which electrical connection work by spot welding is completed. Figure 1 shows the coupling relationship of the battery pack of the plate-like structure of such 2P-3S for convenience of understanding as an exploded view.

As in FIG. 1, three cell pairs of cells 20, 21, each connected in parallel, are connected in series through a metal plate 30 to form a core pack 10.

2 shows a schematic diagram of the battery pack 50 in a state of assembly is completed. For convenience of description, the pack case is omitted.

As shown in FIG. 2, each of the cells 20 and 21 is connected to the protection circuit module 90 through the positive lead 60 and the negative lead 70 and the FPCB 80 connected to the metal plate 30. It is. The electrical connection of the protection circuit module 90 to the metal plate 30 is generally done by soldering.

However, whenever the design of the battery pack is changed, the shape of the connection member must be newly designed to suit it, resulting in an increase in the manufacturing cost of the battery pack. These problems may occur not only in the cylindrical battery but also in the electrical connection of general cells such as square cells.

In addition, the soldering process is a process of connecting the connection part of the protection circuit module in a state in which the solder paste is melted by placing and heating the solder paste on the metal plate. When the metal plate has a smooth surface, the molten solder paste May flow out of the plate, and when the molten solder paste reaches the surface of the battery, the battery may be short-circuited, thereby greatly deteriorating the stability of the battery.

On the other hand, Korean Patent Application Laid-Open Publication No. 2006-027269, in order to prevent the conductive plates connecting a plurality of battery cells from being in close contact with each other, a welding plate welded to the surface of the battery cells and a predetermined distance from the welding plate are extended so as to provide wiring. A conductive plate comprising a solder plate to be soldered is disclosed, wherein a connecting member having an embossed portion formed on at least one of the welding plate and the solder plate is disclosed.

However, the connection member of the above application has a problem in that the bonding force of the solder to the conductive plate is weakened due to the embossed portion. Specifically, the molten lead has a very large surface tension during soldering. When soldering to the embossed portion indented to a predetermined depth, the soldering is carried out while air is collected in the embossed portion due to the large surface tension of the molten lead. Will be done. Therefore, the solidified solder paste does not completely apply the embossed portion, and a predetermined space is formed therein, whereby the bonding area is reduced, thereby lowering the bonding force.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

That is, an object of the present invention is to provide a metal plate having irregularities formed in the connecting portion so as to prevent the short circuit of the battery cell by suppressing the flow of the molten solder paste.

That is, another object of the present invention is to provide metal plates having a specific structure capable of manufacturing various core packs in manufacturing a core pack using a plurality of unit cells.

Another object of the present invention to provide a battery pack manufactured using the metal plate.

Metal plate according to the present invention for achieving this object is a member for electrically connecting a plurality of batteries and additionally connecting a protection circuit to the connection portion, the plate body for welding with the electrode terminal and the protection circuit It comprises a connecting portion protruding to the outer surface of the main body for soldering, the surface of the connecting portion is composed of fine unevenness is formed to suppress the flow of the molten solder paste.

Therefore, the molten solder paste does not flow due to the irregularities formed on the surface of the connecting portion, so that the soldering process becomes much easier, thereby preventing the possibility of causing a short circuit of the battery by the molten solder paste, and It can provide good bonding.

In order to prevent the molten solder paste from flowing, the fine unevenness of the connection portion preferably has a depth of 5 to 35% of the thickness of the plate and a pitch of 40 to 70% of the thickness of the plate. If the depth and pitch are too small, the molten solder paste is more likely to flow. On the contrary, if the depth and pitch are too large, air may be trapped in the uneven portion as described in the related art to reduce the bonding force and the mechanical rigidity of the connecting portion. It is not preferable because it is lowered. The more preferable thickness of the fine concavo-convex is 15 to 25% of the thickness of the plate and the more preferable pitch is 50 to 60% of the thickness of the plate.

The method for forming the fine unevenness of the connection portion is not particularly limited, and all known methods of forming fine unevenness on the surface of the metal material may be used. For example, it may be formed by physical treatment such as rolling, polishing, and / or chemical treatment such as etching.

Preferred examples of the metal plate may include a nickel plate, and the nickel plate may be pure nickel or a thin plate-like body plated with nickel on copper.

The metal plate of the present invention may be composed of three structures exemplified below, and these structures may be formed in any type by appropriate cooking choices when constructing a battery pack by connecting unit cells in a lateral direction and a longitudinal arrangement. It is possible to produce a unit cell arrangement of.

As a first structure, the metal plate may have a structure in which a connecting portion for connection with a protection circuit protrudes on an outer surface of the plate body and a slit is formed in the plate body to facilitate welding with the electrode terminal. Such metal plates are mainly used for electrically connecting unit cells arranged in a lateral direction. The unit cells in this lateral arrangement are preferably connected in parallel.

As a second structure, the metal plate is a plate for electrically connecting the unit cells arranged in the longitudinal direction at the same time as the side direction, the metal plate has a connection portion for connecting to the protective circuit left or right of the plate body A slit protruding from the outer surface, and a slit for facilitating welding with the electrode terminal is formed in the plate body, and may have a structure in which a bent guide groove is formed in the upper and / or lower ends of the central portion of the plate body.

In the third structure, the metal plate has a connection portion for connection with the protection circuit protrudes on the outer surface near the center of the plate body, and a slit is formed in the plate body to facilitate welding with the electrode terminal, the plate body It may be a structure in which the bent induction groove is formed on the top and / or bottom surface of the center of the center.

Therefore, in connecting the unit cells in the lateral and longitudinal arrangements, the metal plates of different structures may be used selectively or together. This means that when connecting unit cells or banks in a series manner of 3S or more, bending in opposite directions is necessary, and when connecting a protection circuit to a core pack, the connection member is positioned at one side of the core pack to minimize such connection length. Because it is preferable to install.

When the battery pack is manufactured by arranging unit cells or banks in a lateral direction, the connecting portions are formed at an angle of 30 to 150 degrees from the plate body so that the connecting portions of the metal plates may be exposed on the upper or lower surface of the battery pack. It is preferable that it is done. If the shape angle of the connection part is too small or too large, some connection parts are located inside the outer circumferential surface of the unit cell, so that the protection circuit is not easily connected.

In one preferred embodiment, a bending guide hole is formed in the connection portion of the metal plate to facilitate vertical bending. The bending guide groove refers to a groove in which the width of the plate body is reduced so that the plate body can be easily bent when the unit cells or banks are arranged in the longitudinal direction in the state in which the unit cell or the bank is welded to the plate body. The bending guide groove may be formed on the top and / or bottom surface of the center of the plate body, preferably, may be symmetrically formed on the top and bottom surfaces of the center of the plate body.

Such combinations of metal plates allow for the fabrication of a wide variety of core packs, including parallel and series connections. Examples of the structure of such a core pack include a linear structure of 2P-3S, a plate structure of 2P-3S, a linear structure of 2P-4S, a plate structure of 2P-4S, and the like.

More details on this are described in Korean Patent Application No. 2005-116659 of the present application, which is incorporated by reference in the context of the present invention.

The present invention also provides a battery pack, which uses a metal plate according to the present invention as a member for electrical connection of a plurality of battery cells.

In particular, by selectively using the three types of metal plates as described above, based on a plurality of unit cells, in particular, cylindrical unit cells based on a battery pack of various structures that form a parallel and series connection It can be manufactured easily. As a result, even if the structure of the battery pack is changed, the three types of metal plates can be selected without the need for separately manufacturing a metal plate, so that the connection member can be shared.

The battery that can be used in the battery cell is possible in various forms, for example, a cylindrical battery or a square battery, preferably a cylindrical battery. The cylindrical battery is generally configured to form a negative electrode terminal on the whole of the battery case in a state in which the positive electrode terminal protrudes at an end thereof and is insulated therefrom. Therefore, when connecting the unit cells in the lateral direction, that is, the positive terminals of the banks in parallel to each other, it is preferable to perform welding of the metal plate with the insulating sheet covering the upper end of the bank so that only the positive terminals are exposed. Do.

The connection of the metal plate to the unit cell or bank is achieved by spot welding. A slit may be formed at a position where the electrode terminal of the unit cell or the bank contacts the plate body, in which case the weldability of spot welding is improved.

After the main body of the metal plate is bonded to the electrode terminal of the battery cell by spot welding, the connecting portion is bent and brought into close contact with the outer surface of the battery cell. Then, it is preferable to perform soldering on the protection circuit. At this time, when the connection part is in close contact, an insulating sheet can be interposed between at least the connection part and the case of the unit battery so as to prevent the connection part from contacting the case of the unit cell. The insulating sheet for insulation of the connection part may be added in a manner of attaching in advance to the outer surface of the unit cell where the connection part will be located when the connection member is connected.

Hereinafter, the content of the present invention will be described with reference to the drawings, but the scope of the present invention is not limited thereto.

3 schematically shows a metal plate according to the first embodiment of the present invention.

Referring to FIG. 3, the metal plate 100 includes a connection part 120 protruding from one end of the plate main body 110 and slits 130 and 131 formed near both ends of the main body 110. The slits 130 and 131 are formed at positions corresponding to the electrode terminals 411 and 421 of the first unit cell 410 and the second unit cell 420 constituting the bank 400. Improve weldability. The connecting portion 120 protrudes from the main body 110 at an angle of about 45 degrees, and a pair of bending guide grooves 121 and 122 are formed in the middle. The upper connection portion 120a, which is a portion that is bent to the side of the battery by the bending guide grooves 121 and 122, has fine irregularities formed on the outer surface thereof so that the molten solder paste does not flow out of the plate. Therefore, the soldering process is much easier and the short circuit can be prevented, thereby improving the safety of the battery. In this figure, the shape of the fine concavo-convex is a lattice shape, but if it can prevent the flow of the solder paste, is not particularly limited, of course, various forms are possible.

4 schematically illustrates a metal plate according to a second embodiment of the present invention, and FIG. 5 schematically illustrates a metal plate according to a third embodiment of the present invention.

First, referring to FIG. 4, the metal plate 200 has a connection portion 220 protruding from one end of the plate body 210 having a length approximately twice that of the first metal plate of FIG. A pair of bending guide grooves 221 and 222 are formed in the grooves. Fine concavities and convexities are formed on the outer surface of the upper connection portion 220a, which is a portion that is bent toward the side of the battery by the bending guide grooves 221 and 222.

Slits 230 and 233 are formed near both ends of the main body 210, and slits 231 and 232 are formed near the central part, and a pair of bending guide grooves 211 and 2 are formed at upper and lower ends of the central part of the main body 210. 212 is formed, and is divided into a main body left part 210a and a main body right part 210b around the bending guide grooves 211 and 212. Therefore, the bank (not shown: a) connected to the main body left part 210a and the bank (not shown: b) connected to the main body right part 210b are bent based on the bending guide grooves 211 and 212.

In the metal plate 300 of FIG. 5, the connecting portion 320 is formed near the center of the plate main body 310, that is, the left side of the main body 310a near the bending guide grooves 311 and 312. Except that it is inclined at an angle symmetrical with respect to the connecting portion 220, it has the same structure as the metal plate 200 of FIG.

FIG. 6 schematically shows a part of a core pack in a battery pack manufactured using the metal plate of the present invention as a connecting member.

Referring to FIG. 6, in the state where the metal sheets are bent to fully unfold the unit cells, and the insulating sheet 500 is attached to a corresponding portion of the battery case corresponding to the connecting portions 220a and 320a, fine unevenness is formed. When the corresponding portions of the formed connection parts 220a and 320a are bent downward and closely contact with each other, a core pack 400 having a linear structure is formed. Since fine concavities and convexities are formed on the surfaces of the connection parts 220a and 320a in close contact with the side parts of the unit cells of the core pack 400, as described above, the molten solder paste is formed on the surface of the battery cell when soldering is performed. Penetration can prevent partial damage or short circuiting. The core pack 400 is connected to the protection circuit module through soldering, FPCB, etc. by soldering to form a battery pack.

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.

As described above, according to the present invention, by suppressing the flow of the molten solder paste during soldering, it is possible to prevent a short circuit caused by the molten solder paste flows out of the plate to contact the surface of the battery cell, the plate body and the protection circuit It is possible to further increase the binding force of. In addition, it is possible to manufacture various battery packs by selecting and selecting metal plates having a specific structure without having to newly design the shape of the connection member to suit the design whenever the design of the battery pack is changed.

Claims (11)

A member for electrically connecting a plurality of batteries and additionally connecting a protection circuit to the connection portion, comprising a plate body for welding with an electrode terminal and a connection portion protruding to an outer surface of the body for soldering of the protection circuit. The surface of the connection portion is formed with fine concavo-convex to suppress the flow of the molten solder paste, the concave-convex portion of the connection portion is 5 to 35% of the depth (depth) of the plate thickness and 40 to the thickness of the plate A metal plate having a pitch of 70%, wherein the shape of the fine unevenness is a lattice shape. delete The metal plate according to claim 1, wherein the fine concavo-convex portion is formed by a physical treatment of rolling or polishing and / or a chemical treatment by etching. The metal plate of claim 1, wherein a connection portion for connection with a protection circuit protrudes on an outer surface of the plate body, and a slit is formed in the plate body to facilitate welding with the electrode terminal. Metal plate. The metal plate of claim 1, wherein a connection portion for connection with a protection circuit protrudes on the left or right outer surface of the plate body, and a slit is formed in the plate body to facilitate welding with the electrode terminal. Metal plate, characterized in that the bending guide groove is formed on the upper surface and / or lower surface of the center of the plate body. The metal plate of claim 1, wherein a connection portion for connection with a protection circuit protrudes on an outer surface near the center of the plate body, and a slit is formed in the plate body to facilitate welding with an electrode terminal. Metal plate, characterized in that the bending guide groove is formed on the upper surface and / or lower surface of the center of the main body. The metal plate according to claim 1, wherein the connecting portion is formed at an angle of 30 to 150 degrees from the plate body. The metal plate according to claim 1, wherein a bending guide groove is formed at a connection portion of the metal plate to facilitate vertical bending. A battery pack comprising a metal plate according to any one of claims 1 and 3 to 8 as a member for electrical connection of a plurality of battery cells. The battery pack as claimed in claim 9, wherein the battery cell is a cylindrical battery. 10. The method of claim 9, wherein after the main body of the metal plate is bonded to the electrode terminal of the battery cell by spot welding, the connecting portion is bent to be in close contact with the outer surface of the battery cell, and then soldered to the protection circuit. Battery pack.

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