KR20090011602A - Connecting method of non-welding type - Google Patents

Abstract

A non-welding type connecting method is provided to prevent the thermal damage and short-circuit possibility of a battery generated in a welding process because a welding process and a soldering process do not need and to minimize the resistance alteration of a terminal connection unit due to a stable coupling structure between the electrode terminals of a battery cell. A non-welding type connecting method is the electrical connection of at least two battery cells (210,220,230,240) using a predetermined connection element(100). The predetermined connection element is a magnetic material capable of intercalation and deintercalation. The electrical connection is carried out by positioning the connection element on the electrode terminal of the battery cells arranged in the side direction and/or the longitudinal direction and cross-coupling battery the cell electrode terminals to the connection element by using the magnetic force of the connection element. The indentation having a shape corresponding to the exterior of the connected portion of the battery cell electrode terminal is formed in the connection element.

Description

Connecting Method of Non-Welding Type

The present invention relates to a method of connecting a non-welding battery cell, and more particularly, to a method of electrically connecting two or more battery cells using a predetermined connection member, and the connection member is easily mounted and detached as necessary. It is made of a magnetic material, the connecting member is positioned on the electrode terminal of the battery cells arranged in the longitudinal and / or lateral direction, the battery cell electrode terminals are mutually coupled to the connecting member by the magnetic force of the connecting member to be electrically connected It provides a connection method to achieve.

As technology development and demand for mobile devices increase, the demand for secondary batteries as a source of energy 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 secondary 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 electrodes may be connected by connecting members such as bus bars after stacking the wide surfaces to face each other. 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 series or in parallel and in series are widely used. As the core pack structure used for 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, 1P The linear structure of -3S and the plate-like structure of 1P-3S are 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 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 having such a plate-like structure of 2P-3S for the 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 in which 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 mainly done by soldering.

In general, a battery pack repeatedly performs a lot of charges and discharges during use, and lithium secondary batteries, which have safety problems under conditions such as external shock, dropping, bed penetration, overcharge, and overcurrent, are mainly used as unit cells. In order to solve this safety problem, a safety device such as a protection circuit module is added. The safety device secures the safety of the pack by acquiring information such as voltage at a corresponding terminal connection portion of the battery pack and performing a predetermined safety process. Therefore, when the connection state of the site is variable, for example, when the resistance value of the terminal connection portion is changed by vibration or the like, due to the inaccuracy of the detection information, the safety device cannot perform the desired process. Therefore, in general, the electrical connection between the battery cell and the protection circuit in the battery pack is made by soldering or the like.

In addition, in order to construct a high-output, high-capacity battery pack, it is necessary to connect a plurality of battery cells in series or in parallel, and stable coupling for minimizing the resistance change of the terminal connection part in order to maintain the performance of the secondary battery pack uniformly. The way is required. The electrical connection between these battery cells is typically made through soldering or welding, preferably spot welding.

However, a welding or soldering process between battery cells has the following problems. Specifically, the welding or soldering process requires the skilled skills and know-how of the operator, and has to continuously manage the parameters for determining the strength of the welding, which leads to complicated production process and increased cost, resulting in increased production efficiency. It acts as a deterrent.

In addition, in the process of directly welding or soldering to a battery cell, a short circuit may occur in the welding part, and electrical or thermal damage may occur between the battery cell and the connection member, which may threaten the safety of the battery and increase the defective rate of the product. . Furthermore, when some battery cells fail during the manufacturing process or use, there is a problem that all battery cells constituting the battery pack should be discarded.

Therefore, it is possible to replace the connection method through welding, soldering, etc., which threatens the stability of the battery and requires a complicated work process, and at the same time, it is possible to reuse the remaining battery cells in case of failure of some battery cells while ensuring a stable connection structure between the battery cells. There is a high need for a technology that can be used.

Meanwhile, in battery packs using primary batteries, various attempts have been made to the electrical connection structure of the connection method. For example, Korean Patent No. 0413381 discloses a technology for forming conductive coils at both ends of left and right sides of a battery case for electrical connection of a battery, and US Patent No. 525037 describes elasticity at both ends of a battery pack. Disclosed is a technical content of making an electrical connection by installing a metal plate bent to have.

However, the above technologies have a problem in that the connection member must have sufficient elasticity to fix the battery cell and to make stable connection with the electrode terminal. In particular, the technique using the conductive coil has a high electric resistance because the cross-sectional area of the wire constituting the coil is small and the connection length is relatively long, and the increased resistance causes power loss and heat generation, resulting in stable connection of the battery. May inhibit. In addition, the technology of using the metal plate bent to have elasticity, due to excessive force or repeated use in the process of inserting the battery cell into the pack case, the metal plate loses elasticity or is destroyed, the external impact on the battery cell When this is applied, a phenomenon of detachment or a disconnection of the electrical connection may occur.

Moreover, the connection member as described above has a limitation in that it is applicable to the battery pack as described above due to the variable connection state at the corresponding site.

Therefore, there is a need for a technology that can replace a connection method through welding and soldering, which threatens the safety of the battery and requires a complicated work process, and at the same time secures a stable connection structure between the battery cells.

The present invention aims 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 method for stably and electrically connecting two or more secondary batteries without performing soldering, welding, and the like, and a battery pack manufactured using the same.

In order to achieve this object, an electrical connection method of a connection member to a battery cell according to the present invention is a method of making an electrical connection of two or more battery cells using a predetermined connection member, wherein the connection member is required. According to the present invention, it is made of a magnetic material to facilitate mounting and detachment, and the connection member is positioned on the electrode terminals of battery cells arranged in the longitudinal direction and / or the lateral direction to connect the battery cell electrode terminals by the magnetic force of the connection member. It is comprised by making mutual connection by mutually connecting to a member.

That is, the electrical connection method of the present invention does not use the soldering and welding process for the electrical connection of the battery cell electrode terminals, and maintains a stable connection structure only by coupling the connection member made of magnetic material and the battery cell electrode terminal, soldering To prevent the possibility of battery short circuit, which can occur during welding, and to ensure that the resistance change of the connection part does not deviate from the reliability level even by an external impact, and at the same time, to facilitate the assembly process of the battery pack, and to ensure stable It can provide a bonding force.

In addition, when a failure occurs during the assembly or use of the battery pack, since the battery cells can be easily separated, some of the battery cells constituting the battery pack due to the failure of the battery cell or the connection member has to be disposed of I can eliminate it.

In some cases, by forming an insulating member on the connecting member and the electrode terminal coupling portion, not only the coupling structure can be formed more stably, but also the respective battery cells and the entire core pack due to the use of the connecting member made of magnetic material. This can prevent the possibility of performance degradation.

In one preferred example, the connection member may be formed with an indentation formed in a shape corresponding to the outer surface of the coupling portion of the battery cell electrode terminal, when the indentation of the connection member is coupled to the connection member and the electrode terminal, Since the coupling portion of the electrode terminal is wrapped, the electrical coupling between the battery cells can be further solidified.

In addition, the battery cell is preferably a cylindrical battery, in this case the indentation may be made of a concentric circle structure. For example, the connection member may be formed in a concentric circle structure having a shape corresponding to the positive terminal and the negative terminal of the cylindrical battery. Since the indentation of this shape can effectively wrap the end where the electrode terminal is formed in the cylindrical battery, it is preferable because it can provide a structurally stable high bonding force.

In general, in a cylindrical battery, a plurality of openings ('gas outlets') for discharging the internal high pressure gas generated in an abnormal operating state of the battery are perforated in the protruding positive electrode terminal. The gas outlet is radially formed at a predetermined distance from the central axis so as not to cause an increase in internal resistance during electrical connection of the secondary battery.

Therefore, in one preferred example, the battery cell may include a protruding positive electrode terminal, and the protruding portion of the positive electrode terminal may have a structure in which a plurality of gas outlets are formed in the circumferential direction.

On the other hand, the connection member is a structure that can easily combine the battery cells arranged in the longitudinal and / or lateral direction, and minimize the increase in the volume of the entire battery pack when mounted in the battery pack case with the battery cells Since it should be formed as, preferably may be made of a plate-shaped magnet.

In addition, the indentation portion of the connecting member is 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, a linear structure of 1P-3S, and 1P. When manufacturing a core pack having various structures, such as a plate-like structure of -3S, a connection member may be formed between a battery and an end portion of the battery so that the cells can be coupled to each other.

Therefore, an indentation is formed on each of the upper and lower surfaces of the connection member, and the lower indentation corresponds to the outer surface shape of the battery cell electrode terminal positioned at the lower portion thereof, and contacts the lower battery cell electrode terminal on the outer circumferential surface thereof. The upper indentation may correspond to the outer surface shape of the battery cell electrode terminal positioned at the upper portion thereof, and may be in contact with the upper battery cell electrode terminal at its outer circumferential surface.

For example, an indentation of a shape corresponding to the shape of the negative electrode terminal of the battery cell is formed on the upper surface of the connection member to contact the negative terminal of the battery cell, and a shape corresponding to the shape of the positive electrode terminal of the battery cell on the lower surface of the connection member. The indentation portion of the battery cell may be formed as a connection member having a structure in contact with the positive terminal of the battery cell. On the contrary, the upper indentation of the connection member may be in contact with the positive terminal of the battery cell, and the lower indentation may be in contact with the negative terminal of the battery cell.

In another preferred embodiment, an insulating member may be mounted or coated on the outer surfaces of the connection member and the battery cell electrode terminal coupling portion.

As mentioned above, since the connection method according to the present invention uses a connection member made of a magnetic material when the battery cells are electrically connected, a magnetic field generated in the connection member is a protection circuit such as a PCM (Protective Circuit Module). Modules may be affected, in which case there is a possibility that the performance of each battery cell and the entire core pack is degraded. Therefore, in order to solve this problem, it is preferable to mount an insulating member or to apply an insulating material to the outer surface of the connecting member and the battery cell electrode terminal coupling portion.

The insulating member is not particularly limited as long as it is a material having insulation against electric and magnetic fields without changing the physical properties and shapes of the connection member and the end of the battery pack. Preferably, the insulating member may be made of a silicon material.

In addition, the insulating member preferably includes a filler for blocking the magnetic field of the connecting member. For example, aluminum filler or ferrite beads having a magnetic field blocking function as a filler may be mixed with the insulating member. Can be used.

The present invention also provides a battery pack for making an electrical connection using the connection method.

The battery pack may be used as a power source for home electronic devices such as portable DVDs, small PCs, and the like, which require high output and large capacity, but is not limited thereto, and particularly preferably used as a power source for notebook computers.

Since the general structure of the battery pack and the notebook computer and its manufacturing method and the like are known in the art, further description thereof will be omitted herein.

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.

3 to 5 are diagrams illustrating developments of a connection method according to various embodiments of the present disclosure.

Referring to these drawings, in the core pack (FIG. 3: 200a) of the 2P-2S structure, the connecting member 100 made of a plate-shaped magnet has a series of cylindrical batteries 210, 220, 230, and 240 having a 2P structure. (2S) is connected. In addition, in the core pack (FIG. 4: 200b) of the 2S structure, the connecting member 110 connects two cylindrical batteries 210, 230 in series with each other, and in the core pack (FIG. 5: 200c) of the 2P structure, The connection member 120 electrically connects two cylindrical batteries 210 and 220 in parallel.

FIG. 6 is a schematic diagram illustrating a process of manufacturing a 2P-2S core pack using a connection member according to an embodiment of the present invention, and FIG. 7 is connected in a state where the core pack of FIG. 6 is embedded in a pack case. A partial schematic diagram showing an enlarged portion of the member and the electrode terminal coupling portion is shown.

First, referring to FIG. 6, the connecting members 100 and 120 are mounted on the positive and negative terminals of the cylindrical batteries 210 and 220, respectively, to be modularized into one bank 310. When another modular bank 320 is connected to the connection member 100 mounted on the bank 310, a core pack 300 having a 2P-2S structure is formed, and further, the 2P-3S and 2P-4S structures are formed. Multicells can be assembled.

Therefore, the core pack 300 of the 2P-2S structure uses the connection members 100 and 120 made of magnets without any soldering or welding, so that the cylindrical batteries 210, 220, 230, and 240 are connected in series and in parallel. The electrical connection prevents the possibility of a short circuit of the battery, which may occur during soldering or welding, and can easily assemble a battery pack having a desired battery capacity.

Next, referring to FIG. 7, a core pack having a 2P-2S structure is mounted on the pack case 410, and two banks 310 and 320 are connected in series by the connection member 100. In addition, the magnetic field generated in the connection member 100 may be blocked by applying silicon (not shown) containing ferrite beads to the coupling portion 420 of the connection member 100 and the electrode terminals.

8 is a front schematic view and a planar schematic view of a connection member having an indentation formed in a shape corresponding to the outer surface of the coupling portion of the electrode terminal, and FIG. 9 is a process of coupling the connection member of FIG. A schematic of is shown.

Referring to these drawings, the lower indentation 102 corresponding to the outer surface shape of the positive electrode terminals of the cylindrical batteries 210 and 220 is formed in a concentric shape on the lower surface of the connecting member 100, and the connecting member 100. An upper indent 104 corresponding to the outer surface of the negative electrode terminals of the cylindrical batteries 230 and 240 is formed on the upper surface of the upper surface.

Accordingly, the lower indentation 102 connects the both terminals of the lower bank 310 positioned in the lower portion of the connecting member 100 in parallel, and the upper indenting portion 104 is the upper bank 320 located above the connecting member. Connect the negative terminals of) in parallel.

In addition, the connection member 100 may easily configure a core pack having a 2P-2S structure by connecting the banks 310 and 320 disposed in the upper and lower portions in series.

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, the method and battery pack for making the electrical connection according to the present invention does not require a welding, soldering process, etc. for the electrical connection of the battery cell electrode terminals, the possibility of thermal damage and short circuit of the battery that may occur during the welding process It can prevent and greatly reduce the defective rate, the stable coupling structure between the electrode terminals of the battery cell can minimize the resistance change of the terminal connection portion, it is possible to significantly improve the production efficiency.

In addition, the battery pack according to the present invention can be easily separated from the battery cell using the connection member of the magnetic material, due to the failure of some of the battery cell or the connection member has to discard all the battery cells constituting the battery pack Can be solved.

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

FIG. 2 is a schematic view showing a battery pack in a state in which a metal plate and a protection circuit of FIG. 1 are connected;

3 to 5 are exploded schematic views of a connection method using the connection member of the present invention;

6 is a schematic diagram of a process for manufacturing a 2P-2S core pack using a connecting member according to one embodiment of the present invention;

7 is an enlarged partial schematic view of the coupling member and the electrode terminal coupling portion in a state where the core pack of FIG. 6 is embedded in the pack case;

8 is a front schematic view and a planar schematic view of a connection member in which an indentation portion having a shape corresponding to the outer surface of the coupling portion of the electrode terminal is formed;

FIG. 9 is a schematic diagram illustrating a process in which the connection member of FIG. 8 is coupled to electrode terminals of a cylindrical battery.

Claims (11)

A method of making an electrical connection between two or more battery cells using a predetermined connection member, wherein the connection member is made of a magnetic material to facilitate mounting and detachment as necessary, and the connection member is longitudinally and / or side-by-side. And the battery cell electrode terminals are electrically connected to the connection member by the magnetic force of the connection member so as to be placed on the electrode terminals of the battery cells arranged in the direction. The connection method according to claim 1, wherein the connection member has an indentation formed in a shape corresponding to the outer surface of the coupling portion of the battery cell electrode terminal. 3. The connection method according to claim 2, wherein the battery cell is a cylindrical battery cell and the indentation forms a concentric circle structure. The connection method according to claim 1, wherein the battery cell includes a protruding positive electrode terminal, and a plurality of gas outlets are formed in the protruding portion of the positive electrode terminal in a circumferential direction. A connecting method according to claim 1, wherein the connecting member is a plate-shaped magnet. According to claim 2, wherein the indentation is formed on the upper surface and the lower surface of the connecting member, wherein the lower indentation corresponding to the outer surface shape of the battery cell electrode terminal located in the lower, the lower battery cell at its outer peripheral surface And an upper indentation part in contact with the upper battery cell electrode terminal at its outer circumferential surface in correspondence with the outer surface shape of the battery cell electrode terminal positioned at the upper portion. The connection method according to claim 1, wherein an insulating member is attached to or coated on the outer surfaces of the connection member and the battery cell electrode terminal coupling portion. 8. The connection method according to claim 7, wherein the insulating member is made of a silicon material. 8. The connection method according to claim 7, wherein the insulating member includes a filler for blocking a magnetic field of the connecting member. A battery pack comprising the electrical connection by using the connection method according to any one of claims 1 to 9. The battery pack as claimed in claim 10, wherein the battery pack is used as a power source for a notebook computer.

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