KR101539236B1 - Battery Cell Having Electrode Lead of Improved Resistance Pressure and Stability - Google Patents

Abstract

The present invention relates to a battery cell having a plate-like structure in which an electrode assembly having a separator structure interposed between the positive electrode and the negative electrode, and a separator structure interposed between the positive electrode and the negative electrode, A first coupling part coupled to one surface of the upper surface and a lower surface of the electrode tap laminate, a second coupling part coupled to the other surface of the electrode tap laminate, And an insulating film interposed between the battery case and the electrode lead, the electrode lead being connected to the first coupling portion and the second coupling portion and exposed to the outside of the battery cell to form an external input / output terminal, Cell.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery cell including an electrode lead having improved pressure resistance and stability,

The present invention relates to a battery cell including an electrode lead having improved pressure resistance and stability, and more particularly, to a battery cell including a positive electrode, a negative electrode, and a plate-like structure having an electrode assembly having a separation membrane structure interposed between the positive electrode and the negative electrode, The battery cell of claim 1, further comprising: electrode tabs protruding from the electrode assembly and not coated with an electrode active material; electrode tabs stacked with the electrode tabs laminated; And a main body which is connected to the first and second coupling parts and is exposed to the outside of the battery cell to form an external input / output terminal, And an insulating film interposed between the battery case and the electrode lead.

As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among such secondary batteries, many studies have been made on lithium secondary batteries having high energy density and discharge voltage, Widely used.

Generally, a secondary battery includes an electrode assembly composed of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, which is laminated or wrapped in a battery case of a metal can or a laminate sheet and then injected or impregnated with an electrolyte solution have.

FIG. 1 schematically shows a typical structure of a typical conventional electrode assembly as a side view.

Referring to FIG. 1, at one end of the electrode assembly 10, a plurality of electrode tabs 20 protrude to be electrically connected to the electrode lead 30. At this time, the electrode tabs 20 are coupled to the electrode leads 30 in a laminated structure. The electrode leads 30 are generally joined by welding to the electrode tabs 20, which may be located on and bonded to the upper or lower surface of the associated electrode tabs 20.

However, the electrode assembly 10 having such a structure has a problem that the bonding strength of the electrode tabs 20 to the electrode leads 30 is reduced. That is, in the electrode assembly 20, the welding for joining of the electrode leads 30 and the electrode tabs 20 proceeds only in one direction, so that the external connection of the electrode leads 30 and the electrode tabs 20, The electrode leads 30 and the electrode tabs 20 are easily separated from each other.

In addition, since the electrode lead is formed by the external input / output terminal, if the length of the electrode lead is increased, the possibility that the electrode lead is broken due to the external force is increased, unnecessary dead space occurs, Assembly is not easy.

Accordingly, there is a high need for a technique capable of improving the bonding force between the electrode leads and the electrode tabs, and more compactly forming the electrode leads, thereby ensuring space reduction and ease of assembling the battery pack.

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 an electrode lead structure of a conventional battery cell, that is, an electrode lead structure of an electrode lead and an electrode tab due to an external force, which is a problem caused by joining a thin and long electrode lead only on one surface, And to provide a battery cell capable of solving the problems of separation and electrode lead breakage and increase in insulation resistance.

It is another object of the present invention to provide a battery pack in which the electrode lead is made compact to reduce the space required for assembling the battery pack, Thereby providing a battery cell.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a battery cell according to the present invention includes a positive electrode, a negative electrode, and a separator structure electrode assembly interposed between the positive electrode and the negative electrode, Electrode tabs having no electrode active material applied thereto; An electrode tab laminate having a structure in which the electrode taps are laminated to each other; A first engaging portion coupled to one surface of the upper surface and a lower surface of the electrode tab laminate, a second engaging portion engaging with the other surface of the electrode tab stack, and a second engaging portion connecting the first engaging portion and the second engaging portion, An electrode lead made of a body exposed to the outside to form an external input / output terminal; And an insulating film interposed between the battery case and the electrode lead.

According to the present invention, by joining the first and second engaging portions and the electrode tab laminate body in a state where the electrode tab laminate body is inserted between the first engaging portion and the second engager portion of the electrode lead, And the welding strength between the electrode lead and the electrode lead can be increased.

In addition, the electrode leads exposed to the outside of the battery case are not elongated, but only the main body forming the external input / output terminal protrudes outside the battery case, so that the electrode leads are deformed by the external force, It is possible to reduce the possibility of occurrence of insulation resistance. Further, the space required for assembling the battery pack can be reduced, and the external input / output terminal can be easily assembled by the contact type.

The electrode assembly is not particularly limited as long as it is composed of an anode, a cathode, and a separator interposed therebetween. For example, the electrode assembly may be a folding type, a stack type, or a stack / folding type structure.

The electrode assembly may be formed in a thickness range of 1.0 mm to 10.0 mm. If the thickness of the electrode assembly is too small, it is necessary to construct a plurality of electrode assemblies to secure a required battery capacity. If the electrode assemblies are too thick, it is difficult to construct the electrode assembly elastically according to the required battery capacity.

Details of the stack / folding type electrode assembly are disclosed in Korean Patent Application Laid-Open Nos. 2001-0082058, 2001-0082059, and 2001-0082060, the contents of which are incorporated herein by reference As a reference.

The electrode tabs may be in a state in which the active material is not coated in order to facilitate coupling between electrode tabs or coupling with the electrode leads. The electrode tabs may be laminated to form an electrode tab laminate, and the electrode tab laminate may have a thickness ranging from 0.1 mm to 5.0 mm. If the thickness of the electrode tab laminate is too thin, there is a risk of breakage due to an external impact, and if it is too thick, the electrode tab laminate may not be easily coupled with the electrode lead.

The first and second coupling portions of the electrode lead are respectively coupled to one surface of the upper surface and the lower surface of the electrode tab laminate. The electrode lead and the electrode tab laminate are easily coupled with each other, Shaped structure so as to be able to be formed. Wherein the main body, the first engaging portion, and the second engaging portion are formed integrally with each other, wherein the main body, the first engaging portion, and the second engaging portion are integrally formed, May be formed in a continuous structure from the end of the first engagement portion to the end of the second engagement portion.

Specifically, the electrode leads may be formed in a " C " Accordingly, the electrode tab laminate is inserted into the depressed portion of the electrode lead, and the electrode lead can be coupled to the electrode tab laminate so as to surround the electrode tab laminate. Such a stable structure can increase the rigidity of the portion where the electrode tab laminate and the electrode lead are coupled.

An external pressure is applied to the electrode lead laminate when the electrode tab laminate is inserted into the depressed portion of the electrode lead and when the electrode lead laminate is welded to the electrode tab or when the battery case and the electrode lead are sealed. And a portion where the first and second coupling portions of the electrode lead are in contact with each other. In order to prevent the electrode lead from being broken due to such stress, the vertical cross-sectional thickness of the main body may be thicker than the vertical cross-sectional thickness of the first and second engaging portions.

Specifically, the average vertical cross-sectional thickness of the body may be in the range of 120% to 500% of the average vertical cross-sectional thickness of the first and second engagement portions.

The width of the electrode leads may be in a range of 110% to 150% of the width of the electrode tabs so as to cover both the top and bottom surfaces of the electrode tabs. If the width of the electrode lead is too small, the contact surface with the electrode tab is small, so that the bonding force can be weakened. On the other hand, if the width of the electrode lead is too large, an unnecessary dead space occurs between the first and second coupling parts.

The material of the electrode lead is not particularly limited as long as it is made of a material that can be electrically connected to the electrode tab. Specifically, aluminum, aluminum alloy, copper, copper alloy, nickel and nickel alloy can be cited. It is not.

The electrode tab laminate and the battery leads can be bonded in various ways, specifically, more stably by welding, and such welding can be carried out by, for example, ultrasonic welding, resistance welding, Laser welding, spot welding, or the like.

An insulating film may be interposed between the battery case and the electrode lead to prevent short circuit between the battery case and the electrode lead. Specifically, the material of the insulating film may be a sealant or a caulking material, but is not limited thereto.

The first and second coupling portions of the electrode tab laminate and the electrode lead may be sealed inside the battery case to prevent a short circuit, and the main body may protrude out of the battery case.

Since the electrode lead protrudes from the battery case only to the outside of the battery case, the electrode lead is deformed due to an external impact to reduce the possibility that the battery case and the insulating film may be broken, .

In addition, the main body protrudes to the outside to form an external input / output terminal, and a current is applied in a terminal contact manner. Therefore, in order to stably contact the external device, the main body may be formed parallel to a corresponding surface of the battery case in which the main body is located. Such a structure can reduce the space required for assembling the battery pack, and facilitates assembly due to the terminal contact method.

The battery cell is not particularly limited as long as it is a secondary battery capable of providing a high voltage and a high current when the battery pack is constructed. For example, the battery cell may be a lithium secondary battery having a large energy storage amount per volume.

The battery pack may be suitably used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, a power storage device and the like in consideration of structural stability and the like, but is not limited thereto.

Accordingly, the present invention provides a device comprising the battery pack as a power source, and the device can be specifically an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or a power storage device.

The structure and manufacturing method of such a device are well known in the art, so a detailed description thereof will be omitted herein.

As described above, in the battery cell according to the present invention, the electrode tab laminate is inserted between the first and second coupling parts of the electrode lead, and the first and second coupling parts and the electrode tap lamination It is possible to increase the welding strength between the electrode tab laminate and the electrode lead.

In addition, the electrode leads exposed to the outside of the battery case are not elongated, but only the main body forming the external input / output terminal protrudes outside the battery case, so that the electrode leads are deformed by the external force, It is possible to reduce the possibility of occurrence of insulation resistance. Further, the space required for assembling the battery pack can be reduced, and the external input / output terminal can be easily assembled by the contact type.

FIG. 1 is a side view showing a connection structure of a battery tab and an electrode lead of a conventional battery cell; FIG.
2 is a schematic view of a battery cell according to one embodiment of the present invention;
3 is a schematic view showing the structure before the electrode leads are coupled to the electrode tab laminate in the battery cell of FIG. 2;
4 is a side view of the structure in which the electrode tab laminate and the electrode lead of the present invention are combined;
5 is a number plan view of an electrode tab laminate and an electrode lead of the present invention;
6 is a side view of a structure in which an insulating film is interposed between a battery case and an electrode lead of the present invention;
Fig. 7 is a perspective view of Fig. 2. Fig.

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.

2 is a schematic view of a battery cell according to an embodiment of the present invention.

2, the battery cell 100 includes an electrode assembly 110, an electrode tab stack 120, an electrode lead 130, and a battery case 140. The electrode assembly 110 is impregnated with an electrolyte in the battery case 140.

Specifically, the electrode assembly 110 has a thickness W1 of 1.0 mm to 1.0 mm. The thickness W1 of the electrode assembly 110 can be flexibly adjusted according to the required battery capacity.

FIG. 3 is a schematic view showing a structure before the electrode leads are coupled to the electrode tab laminate in the battery cell of FIG. 2. FIG. 4 is a side view of the structure in which the electrode tab laminate and the electrode leads of the present invention are combined. And FIG. 5 is a top plan view of the electrode tab stack body and the electrode leads.

3 to 5, the electrode tab laminate 120 has a structure in which the electrode tabs 121 are coupled in a laminated state. The electrode tabs 121 protrude from the electrode assembly 110 and are not coated with an active material in order to facilitate coupling between the electrode tabs 121 and the electrode leads 130.

The electrode tab stack body 120 has a thickness W2 of 0.1 mm to 5.0 mm. The thickness W2 of the electrode tab laminate 120 can be adjusted to reduce the risk of breakage due to an external impact and to facilitate bonding with the electrode lead 130. [

The electrode lead 130 includes a first coupling portion 131 and a second coupling portion 132 and a main body 133. The first coupling portion 131 and the second coupling portion 132 are formed in a plate-like structure in order to facilitate coupling between the top and bottom surfaces of the electrode tap stack and to minimize the size after coupling. The main body 133 is coupled to the right end of the first engaging part 131 and the second engaging part 132 to be engaged with the first engaging part 131, (131) and the second engaging portion (132). The portion where the first engaging portion 131 and the second engaging portion 132 are in contact with the main body 133 is bent vertically. The first coupling portion 131 and the second coupling portion 132 and the main body 133 have a "C" shape in a vertical section, and are integrally formed at the left end of the first coupling portion 131, To the left end portion of the portion 132.

The vertical cross-sectional thickness W3 of the body 133 is thicker than the vertical cross-sectional thickness W4 of the first and second engagement portions. The vertical section thickness W3 of the main body 133 is formed to be 120% to 500% of the vertical section thickness W4 of the first and second engaging portions. By forming the vertical cross-sectional thickness W3 of the main body 133 to be larger than the vertical cross-sectional thickness W4 of the first engaging portion and the second engaging portion, it is possible to prevent breakage that may occur when an external pressure is applied to the electrode lead 130 have. The width W5 of the electrode lead 130 is 110 to 150% of the width W6 of the electrode tab 121. [ The width W5 of the electrode lead 130 is formed to be larger than the width W6 of the electrode tab 121 so that the electrode lead 130 completely covers the electrode tab 121 and can be firmly connected.

The electrode tab laminate 120 is inserted into the depressed portion of the electrode lead 130 so that the electrode lead 130 surrounds the electrode tab laminate 120. The top and bottom surfaces of the electrode tab stack 120 may be joined to the first and second engaging portions 131 and 132 to improve the rigidity.

6 is a vertical sectional view of a structure in which an insulating film is interposed between a battery case and an electrode lead of the present invention.

6, an insulating film 150 is interposed between the upper surface and the lower surface of the battery case 140 and the electrode lead 130, respectively. The insulating film 150 can reduce the risk of a short circuit that may occur between the battery case 140 and the electrode lead 130.

Fig. 7 is a perspective view of Fig.

Referring to FIG. 7, as shown in FIG. 6, in order to prevent a possibility that a short circuit may occur between the first coupling part 131 and the second coupling part 132 of the electrode lead 130 and the electrode tap laminate 120 And is formed to be sealed inside the battery case 140. Only the main body 133 protrudes to the outside of the battery case 140 so that the possibility that the electrode lead 130 is deformed by the external impact and the battery case 140 and the insulating film 150 are broken can be reduced, The occurrence of insulation resistance can be prevented.

The main body 133 forms an external input / output terminal, and current is applied in a terminal contact manner. The main body 133 is formed parallel to the front surface of the battery case 140, and stably contacts the external device. Such a structure can reduce the space required for assembling the battery pack, and facilitates assembly due to the terminal contact method.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

A battery cell having a plate-like structure having an anode, a cathode, and an electrode assembly having a separator structure interposed between the anode and the cathode,
Electrode tabs protruding from the electrode assembly and not coated with an electrode active material;
An electrode tab laminate having a structure in which the electrode taps are laminated to each other;
A first engaging portion coupled to one surface of the upper surface and a lower surface of the electrode tab laminate, a second engaging portion engaging with the other surface of the electrode tab stack, and a second engaging portion connecting the first engaging portion and the second engaging portion, An electrode lead made of a body exposed to the outside to form an external input / output terminal; And
An insulating film interposed between the battery case and the electrode lead;
/ RTI >
The first and second coupling parts of the electrode lead are respectively in a plate-like structure. The main body is continuous from the first coupling part to the second coupling part in a form integrated with the first coupling part and the second coupling part In addition,
Wherein the electrode lead is formed in a " C "shape in a vertical cross section. The battery cell according to claim 1, wherein the electrode assembly has a stacked or stacked / folded structure. The battery cell according to claim 1, wherein the thickness of the electrode assembly is 1.0 mm to 10.0 mm. The battery cell according to claim 1, wherein the thickness of the electrode tab laminate is 0.1 mm to 5.0 mm. delete delete The battery cell according to claim 1, wherein a thickness of the vertical section of the body is thicker than a thickness of a vertical section of the first and second engaging portions. The battery cell according to claim 7, wherein the average vertical cross-sectional thickness of the body is 120% to 500% of the average vertical cross-sectional thickness of the first and second engaging portions. The battery cell according to claim 1, wherein a width of the electrode lead is 110% to 150% of a width of the electrode tab. The battery cell according to claim 1, wherein the material of the electrode lead is selected from the group consisting of aluminum, an aluminum alloy, copper, a copper alloy, nickel, and a nickel alloy. The battery pack according to claim 1, wherein the electrode tab laminate and the battery lead are welded and joined by at least one welding method selected from the group consisting of ultrasonic welding, resistance welding, heat welding, laser welding, and spot welding Battery cell. The battery cell according to claim 1, wherein the insulating film is made of a sealant or caulking material. The battery pack according to claim 1, wherein the first and second engaging portions of the electrode tab laminate and the electrode lead are sealed inside the battery case, and the main body protrudes to the outside of the battery case . 14. The battery cell according to claim 13, wherein the main body protrudes in parallel with an end of the main body with respect to a corresponding surface of the battery case in which the main body is located. The battery cell according to claim 1, wherein the battery cell is a lithium secondary battery. A battery pack comprising at least two battery cells according to any one of claims 1 to 4 and claims 7 to 15. The device according to claim 16, comprising a battery pack as a power source. 18. The device of claim 17, wherein the device is selected from a cell phone, a portable computer, a smart phone, a smart pad, a netbook, a LEV (Light Electronic Vehicle), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, ≪ / RTI >

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