KR101749718B1 - Secondary Battery Pack Plated with Welding Metal - Google Patents

Abstract

The present invention relates to a battery cell in which an electrode assembly having a positive electrode / separator / negative electrode structure is sealed inside a battery case together with an electrolytic solution, and electrode terminals are formed at an upper end thereof; A PCM assembly comprising a terminal connection part formed on a lower surface of the PCM so that the protection circuit module (PCM) and the following connection members are coupled to each other, the connection through-hole being perforated; An insulating mounting member mounted on an upper surface of the battery cell and having an opening to expose the electrode terminals of the battery cell, a protection circuit module mounted on the upper surface, A protection circuit module (PCM) mounted on the insulating mounting member and having a protection circuit for controlling overcharge, overdischarge, and overcurrent; A first connecting member and a second connecting member for electrically connecting the electrode terminal of the battery cell and the terminal connecting portion of the PCM; And an insulating cap coupled to an upper end of the battery cell while enclosing the insulating mounting member in a state where the PCM is mounted; Wherein the battery case includes a case body having an open upper end for inserting an electrode assembly and a base plate coupled to an open upper end of the case body, And the second connecting member is joined to the upper surface of the base plate by resistance welding, except for the protruding terminal, and the upper surface of the base plate is welded to a portion where the second connecting member is coupled And a metal for plating is plated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a secondary battery pack,

The present invention relates to a secondary battery pack, and more particularly, to a secondary battery pack comprising a battery cell, an insulating mounting member, a protection circuit module (PCM), and connection members, wherein the battery case comprises a case body and a base plate, And the upper surface of the base plate is plated with a welding metal at a portion to which the connecting member is coupled so that the PCM and the battery cell can be easily coupled by resistance welding.

Lithium rechargeable batteries, which have been recently used, have a variety of combustible materials, and thus have a serious safety problem because of the risk of overheating, overcurrent, other physical external impact, and the like. Therefore, the lithium secondary battery is mounted with a protection circuit module (PCM), which is capable of effectively controlling an abnormal state such as overcharging, connected to the battery cell.

Generally, the PCM is connected to the battery cell by welding or soldering. For example, after a clad is attached to some electrode terminals of a battery cell, a nickel plate as a connecting member is welded to a connection terminal of the PCM and an electrode terminal of the battery cell, respectively, A battery pack is manufactured.

The clad is required when the battery case is joined to the positive electrode, which is a battery case, in a rectangular battery cell made of an aluminum can by resistance welding.

To this end, the clad is attached to a corresponding portion of the battery case, and one end of the nickel plate is welded to the clad. However, due to the small structure of the battery cell, it is necessary to proceed with precise work. In addition, there is a problem that the manufacturing cost of the battery pack increases due to the use of the clad.

Therefore, there is a high need for a technique that simplifies the assembly process by reducing the number of members used in manufacturing the battery pack, and minimizes the occurrence of defects during the assembly process.

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

Specifically, it is an object of the present invention to provide a battery pack which can reduce the number of members required for the battery pack and simplify the assembling process, thereby reducing the manufacturing cost of the battery and providing excellent structural stability.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein,

A battery cell 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 electrode terminals are formed at an upper end thereof;

A PCM assembly comprising a terminal connection part formed on a lower surface of the PCM so that the protection circuit module (PCM) and the following connection members are coupled to each other, the connection through-hole being perforated;

An insulating mounting member mounted on an upper surface of the battery cell and having an opening to expose the electrode terminals of the battery cell, a protection circuit module mounted on the upper surface,

A protection circuit module (PCM) mounted on the insulating mounting member and having a protection circuit for controlling overcharge, overdischarge, and overcurrent;

A first connecting member and a second connecting member for electrically connecting the electrode terminal of the battery cell and the terminal connecting portion of the PCM; And

An insulating cap coupled to an upper end of the battery cell while surrounding the insulating mounting member in a state where the PCM is mounted;

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The battery case includes a case body having a top opened to insert an electrode assembly, and a base plate coupled to an open upper end of the case body,

The first connecting member is coupled to the protruding terminal of the base plate by resistance welding and the second connecting member is coupled to the upper surface of the base plate except for the protruding terminal by resistance welding,

And the upper surface of the base plate is plated with a welding metal at a portion to which the second connecting member is coupled.

The inventors of the present application have found that when the welding metal is plated on the upper surface of the base plate of the battery case as described above, the connecting member electrically connects the PCM and the battery cell by resistance welding without using a separate clad, It was confirmed that the secondary battery pack can be easily assembled. Therefore, in the secondary battery pack according to the present invention, since the electrical connection of the PCM to the battery cell is achieved without using a separate clad, the manufacturing process can be simplified, and the raw material and personnel can be saved.

In addition, since the secondary battery pack according to the present invention is welded to the connecting member in a state where the PCM is mounted on the battery cell, the connecting member having a relatively long length is connected to the battery cell, The space required for bending the connecting member in the process of mounting the PCM is greatly reduced as compared with the conventional secondary battery pack to be mounted, and the capacity per unit volume of the secondary battery pack can be increased.

The first connecting member may be a cathode connecting member, and the second connecting member may be an anode connecting member. For example, a prismatic battery cell has a structure in which an electrode terminal and a battery case protruded from an upper surface thereof are respectively a cathode and a cathode terminal, and an insulating member is interposed therebetween to form mutual insulation. Therefore, the first connecting member connected to the negative terminal, and the second connecting member connected to the upper end surface except for the protruding terminal of the base plate constituting the positive electrode terminal are connected to the circuits in the PCM and the electrode assembly Can be electrically connected.

Preferably, the second connecting member is composed of a PCM coupling portion coupled to the terminal connection portion of the PCM, a battery cell coupling portion coupled to the upper end surface of the battery cell, and a PTC device interposed therebetween, When the temperature suddenly rises due to internal short-circuit or the like of the battery pack, the second connecting member coupled with the PTC element serves to cut off the current in the upper assembly of the battery pack, thereby improving the safety of the battery pack.

At this time, the first connecting member and the second connecting member are not particularly limited as long as they are made of a conductive material, but they may preferably be made of nickel or a nickel alloy. It is possible to more easily connect the circuits of the PCM and the electrode assembly inserted into the battery case by using a nickel or nickel alloy having good electrical conductivity and good ductility and softness as the connecting member.

In one preferred embodiment, the insulating mounting member has a size smaller in the longitudinal direction than the upper surface of the battery cell so as to secure a portion where the second connecting member is connected to the battery cell, and the negative terminal of the battery cell is exposed And a second opening exposing the upper end of the case upper end portion of the battery cell (the sealed electrolyte inflow portion) is formed at a predetermined distance from the first opening.

Therefore, since the insulating mounting member is formed to have a smaller length in the longitudinal direction than the upper end surface of the battery cell, a space in which the connecting member A can be positioned between one end of the PCM assembly and one end of the upper end of the battery cell Can be secured.

In addition, since the case body of the battery case requires ease of processing and mechanical strength of a certain level or more, it may be made of a metal can, and preferably an aluminum can or a stainless steel can. Furthermore, an external film may be attached to the outer surface of the battery case. Thus, the battery cell can be protected from external impact and maintained in an electrically insulated state.

As described above, according to the present invention, the welding metal is plated on the upper surface of the base plate where the second connecting member is engaged.

In some cases, the base plate may be plated with a welding metal on the entire upper surface excluding the protruding terminal, and further, the base plate may be formed on the entire upper surface excluding the protruding terminal, The metal may be plated. As described above, in the case of plating the entirety of the upper end surface of the base plate or the entire upper end surface and the entire lower end surface of the base plate with welding metal, personnel and raw materials can be further reduced and the process can be simplified.

The welding metal may be, for example, nickel or a nickel alloy. When the resistance of the two metals is the same, resistance can be more easily achieved when the two metals are resistance-welded. Therefore, if the same metal as the second connection member is used as the welding metal, the effect of the present invention can be further maximized .

The thickness of the welding metal may be, for example, 0.001 to 1.0 mm. If the thickness of the welding metal is too small, the welding member can not achieve the desired effect of the present invention because the thickness is too small for resistance welding with the second connecting member. If the thickness of the welding metal is too thick, There is a problem that the battery capacity of the battery pack is reduced by the thickness of the metal for the battery pack.

In one specific example, the second connecting member coupled to the upper surface of the base plate may be provided with an insulating tape for insulation from a portion other than the terminal connecting portion of the PCM, and more particularly, It can be a double-sided adhesive tape. In addition to the insulating effect, when the insulating tape is a double-sided adhesive tape, the bonding force between the second connecting member and the PCM and the base plate is further strengthened at the time of assembling the battery pack.

The secondary battery pack according to the present invention can be applied to various types of battery cells regardless of the type and external shape of the battery cell, and preferably to a battery pack including a prismatic lithium secondary battery as a battery cell.

The present invention also provides a device including the battery pack as a power source.

The device may be selected from a mobile phone, a portable computer, a smart phone, a tablet PC, a smart pad, a netbook, a wearable electronic device, a notebook computer, and the like. The structure of these devices and their fabrication methods are well known in the art, and a detailed description thereof will be omitted herein.

The present invention also provides a method of manufacturing the secondary battery pack.

Specifically, the secondary battery pack according to the present invention may be manufactured by a method including plating a base plate of the battery case with a metal ion aqueous solution.

The method may further include the step of attaching a plating preventing tape to the remaining portion of the base plate excluding the joining portion of the second connecting member before the plating process as described above, And a step of attaching an anti-plating tape to the lower end surface of the base plate before the plating process.

Such a manufacturing method can provide a secondary battery pack in which the number of working steps is reduced and the structural stability is improved as compared with a conventional battery pack manufacturing process using a clad.

As described above, in the secondary battery pack according to the present invention, by welding the welding metal to the upper surface of the base plate of the battery case, resistance welding can be performed between the connecting member and the base plate without a separate clad, , The work process can be simplified, and the structural stability can be improved.

Furthermore, the secondary battery pack according to the present invention can provide the maximum capacity in the same battery pack standard by a specific internal structure.

1 is an exploded perspective view of a secondary battery pack according to an embodiment of the present invention;
2 is a schematic view of a structure in which connecting members are coupled to a lower surface of a PCM assembly;
FIGS. 3 to 5 are partial schematic views for explaining a series of processes for assembling the secondary battery pack of FIG. 1 step by step; FIG.
6 is a schematic exploded view of an upper structure of a battery cell according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

1 is an exploded perspective view of a secondary battery pack according to an embodiment of the present invention.

Referring to FIG. 1, a secondary battery pack 100 includes a battery cell 110 in which an electrode assembly is sealed in a battery case together with an electrolyte, a PCM assembly 120 for effectively controlling an abnormal condition such as overcharging, An insulating mounting member 130 on which the PCM assembly 120 is mounted and mounted on the upper surface 114 of the base plate of the battery cell 110 and an insulating mounting member 130 mounted on the PCM assembly 120 An insulative lower cap 150 coupled to a lower end of the battery cell 110 and an insulative lower cap 150 coupled to the upper end of the battery cell 110 to surround the battery cell 110. [ And a film (160).

A protruding terminal 112 protruding upward from the battery case in a state insulated from the battery case is formed on the upper end surface 114 of the base plate of the battery cell 110. The protruding terminal 112, The other part forms a bipolar terminal. In addition, the electrolyte injection portion 116 sealed with a metal ball, a polymer resin, or the like projects in a circular shape on a plane. A portion 111 where the welding metal is plated is formed on one side of the upper end surface 114 of the base plate of the battery cell 110.

The insulating mounting member 130 is mounted on and bonded to the upper surface 114 of the base plate of the battery cell 110 in an adhesive manner so that the protruding terminal 112 of the battery cell 110 can be exposed upward A first opening 132 is formed at a central portion of the insulating mounting member 130 and a second opening 134 is formed at a right side portion of the insulating mounting member 130 so that a part of the upper end surface 114 of the base plate of the battery cell 110 is exposed. Is formed.

The PCM assembly 120 is connected to the lower surface of the connecting member 124, and the welding through-hole 122 is formed at the central portion.

The insulating upper cap 140 is coupled to the upper end of the battery cell 110 while covering the insulating mounting member 130 in a state where the PCM assembly 120 is mounted and covers the upper end of the battery cell 110 And the A / S label 142 is attached to one side of the upper surface.

The outer surface of the battery case is attached with an outer film 160 for securing an electrically insulated state from the outside and displaying information on the product. The covering film 160 made of a heat-shrinkable material is manufactured in a tube shape and attached to the battery cell 110 in a structure in which the battery cell 110 is wrapped around the battery cell 110,

Fig. 2 is a schematic view of a structure in which connecting members are coupled to the lower surface of the PCM assembly.

Referring to FIG. 2 together with FIG. 1, a pair of connecting members 123 and 128 are coupled to a lower surface of the PCM assembly 120. The second connecting member 123 electrically connected to the upper end surface 114 of the base plate of the battery cell 110 is connected between the PCM coupling part 126 of the plate shape and the battery cell coupling part 124 of the plate- And the battery cell engaging portion 124 protrudes from the outer end of the PCM assembly 120. As shown in FIG. Also, the first connecting member 128 is coupled to the lower surface of the PCM assembly 120 by the SMT method in such a manner as to completely seal the welding through-hole (FIG. 1: 122).

The second connecting member 123 is welded to the upper end surface 114 of the base plate which is the positive terminal of the battery cell 110 and the first connecting member 128 is connected to the negative terminal of the battery cell 110 The battery cell 110 and the PCM assembly 120 can be electrically connected to each other.

Since the connection members 123 and 128 are connected to the electrode terminals of the battery cell 110 in a state that the connection members 123 and 128 are not bent as shown in FIG. 2, a connecting member having a smaller size than that of the conventional method can be used, It does not cause a dead space for bending.

FIGS. 3 to 5 are partial schematic views for explaining a series of processes for assembling the secondary battery pack of FIG. 1 step by step.

3 shows a structure in which the insulating mounting member 130 is coupled to the upper end surface 114 of the base plate of the battery cell 110. In FIG 3, The protruding terminal 112 of the battery cell 110 is exposed through the first opening 132 of the insulating mounting member 130 and is exposed to the top, The sealed electrolyte infusion portion 116 of the battery cell 110 is exposed through the second opening 134 to the upper portion of the insulating mounting member 130.

The length l of the insulating mounting member 130 is shorter than the length L of the upper end of the battery cell 110 and the length L of the insulating mounting member 130 is shorter than the length L of the upper end of the upper surface 114 of the base plate of the battery cell 110, And a portion 111 to which a welding metal is to be plated for connection of the second connecting member (Fig. 1: 123) is formed in a part L1.

4, a structure in which the PCM assembly 120 is coupled to the structure of FIG. 3 is shown in FIG. 4. Referring to FIG. 4, the second connecting member 123 is placed in a region 111 where a welding metal is plated, After the first connecting member 128 is positioned on the protruding terminal (FIG. 3: 112) of the battery cell 110, electrical connection and mechanical connection structure can be achieved by welding, respectively.

5 is a schematic view illustrating a structure in which the insulating upper cap 140 is coupled to the structure of FIG. 4. Referring to FIG. 5, the insulating upper cap 140 is provided with an insulating mounting member (Not shown) is formed at a position corresponding to the insulating cap member (not shown), and a fastener (not shown) of the insulating upper cap 140 is fastened to the fastening groove (Not shown) so as to mechanically fasten each other.

6 is a schematic exploded view of a top structure of a battery cell according to another embodiment of the present invention.

6, the base plate 214, the rivet 212a, the upper gasket 212b of the upper surface 211 of the battery cell, and the lower gasket and the lower plate, not shown in the figure, . A metal for welding is plated not only on one side of the top surface 211 of the base plate 214 but also on the entire upper surface 211 excluding the rivet 212a and the upper gasket 212b where the protruding terminal is located , Although not shown in the figure, the entire lower surface of the base plate 214 may also be plated with a welding metal.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (21)

A battery cell in which an electrode assembly having a positive electrode / separator / negative electrode structure is sealed inside a prismatic battery case together with an electrolytic solution, and electrode terminals are formed at an upper end thereof;
A PCM assembly comprising a terminal connection part formed on a lower surface of the PCM so that the protection circuit module (PCM) and the following connection members are coupled to each other, the connection through-hole being perforated;
An insulating mounting member mounted on an upper surface of the battery cell and having an opening formed therein for exposing electrode terminals of the battery cell, a protection circuit module mounted on the upper surface of the battery cell,
A protection circuit module (PCM) mounted on the insulating mounting member and having a protection circuit for controlling overcharge, overdischarge, and overcurrent;
A first connecting member and a second connecting member for electrically connecting the electrode terminal of the battery cell and the terminal connecting portion of the PCM; And
An insulating cap coupled to an upper end of the battery cell while surrounding the insulating mounting member in a state where the PCM is mounted;
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The battery case includes a case body having a top opened to insert an electrode assembly, and a base plate coupled to an open upper end of the case body,
The first connecting member is coupled to the protruding terminal of the base plate by resistance welding and the second connecting member is coupled to the upper surface of the base plate except for the protruding terminal by resistance welding,
Wherein the base plate is plated with a welding metal on the entire upper surface except for the protruding terminal. The battery pack according to claim 1, wherein the first connecting member is coupled to a lower surface of the PCM so that at least a part of the first connecting member can be exposed to the upper portion of the PCM assembly through the connecting through-hole. The battery pack according to claim 1, wherein the second connecting member protrudes from one end of the PCM assembly so that a portion electrically connected to the battery cell can be exposed to an upper portion of the PCM assembly. The battery pack according to claim 1, wherein the electrical connection between the connection member and the battery cell electrode terminals is achieved from the top of the PCM with the insulating mounting member and the PCM assembly mounted on the battery cell. The battery pack according to claim 1, wherein the first connecting member is a negative electrode connecting member, and the second connecting member is a positive electrode connecting member. The battery pack according to claim 1, wherein the first connecting member and the second connecting member are made of nickel or a nickel alloy, respectively. The battery pack of claim 1, wherein the insulating mounting member has a size smaller than a top surface of the battery cell in the longitudinal direction so as to secure a portion to which the second connecting member is connected to the battery cell, And a second opening exposing the case upper end protrusion (sealed electrolyte inflow portion) of the battery cell upward at a predetermined distance from the first opening. The battery pack according to claim 1, wherein the case body of the battery case is a metal can. delete The battery pack according to claim 1, wherein the base plate is plated with a welding metal on the entire upper surface and the entire lower surface except for the protruding terminal. The battery pack according to claim 1, wherein the welding metal is nickel or a nickel alloy. The battery pack according to claim 1, wherein the plating metal has a plating thickness of 0.001 to 1.0 mm. The battery pack according to claim 1, wherein an insulating tape is provided on the second connecting member coupled to the upper surface of the base plate for insulation from a portion other than the terminal connecting portion of the PCM. 14. The battery pack according to claim 13, wherein the insulating tape is a double-sided adhesive tape. The battery pack according to claim 1, wherein an outer film is attached to an outer surface of the battery case. The battery pack according to claim 1, wherein the battery cell is a lithium secondary battery cell. A device comprising a battery pack according to any one of claims 1 to 8 and 10 to 16. 18. The device of claim 17, wherein the device is a mobile phone, a portable computer, a smart phone, a tablet PC, a smart pad, a netbook, a wearable electronic device, or a notebook computer. The method for manufacturing a battery pack according to any one of claims 1 to 8 and 10 to 16, further comprising the step of plating the base plate of the battery case by supporting the base plate in a metal ion aqueous solution Of the battery pack. The method of manufacturing a battery pack according to claim 19, further comprising the step of attaching an anti-plating tape to a remaining portion of the base plate excluding a joining portion of the second connecting member before the plating process . 20. The method of claim 19, further comprising the step of attaching an anti-plating tape to a lower surface of the base plate before the plating process.

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