KR101863702B1 - Lead Assembly for Preventing Explosion of Battery Cell and Battery Cell Including the Same - Google Patents

Abstract

The present invention relates to a lead assembly constituting an electrode lead of a pouch type battery cell, the lead assembly comprising: a first lead having a plate shape and made of an electrically conductive metal; A second lead electrically connected to the electrode tabs of the battery cell; A third lead between the first lead and the second lead, one side of which is electrically connected to the first lead and the other side of which is electrically connected to the second lead; A first housing which accommodates at least a part of the third lead on one side and mechanically engages with the second lead on the other side; And a second housing formed with grooves into which at least a part of the first lead and the third lead are inserted and fixed and mechanically fastened to the first housing with the first lead and the third lead inserted therein And the electrical connection portion between the second lead and the third lead is broken when the internal pressure of the battery cell rises, and is cut off.

Description

Technical Field [0001] The present invention relates to a lead assembly for preventing explosion of a battery cell and a battery cell including the same,

A lead assembly for preventing explosion of a battery cell, and a battery cell including the same.

As information technology (IT) technology has developed remarkably, various portable information and communication devices have been spreading, so that the 21st century is being developed into a "ubiquitous society" capable of providing high quality information services regardless of time and place.

In the development base for the ubiquitous society, the lithium secondary battery cell occupies an important position. Specifically, battery cells capable of charging and discharging are widely used as energy sources for wireless mobile devices or wearable electronic devices worn on the body, as well as for air pollution such as gasoline vehicles and diesel vehicles using fossil fuels And is also used as an energy source for electric vehicles, hybrid electric vehicles, and the like, which are proposed as solutions for solving the above problems.

As described above, as the devices to which the battery cells are applied are diversified, the battery cells are diversified so as to provide an appropriate output and capacity for the applied devices.

On the other hand, the heat accumulation occurs when the heat generated in the charge / discharge process of the battery cell can not be effectively removed. In particular, deterioration of the battery cell is generally caused by a rapid temperature rise due to overcharging of the battery cell.

Specifically, when the battery cell is overcharged to about 4.5 V or more, decomposition reaction of the positive electrode active material occurs, and dendrite growth of lithium metal and decomposition reaction of the electrolyte occur in the negative electrode. In this process, the decomposition reaction and the many side reactions are rapidly proceeded with heat accompanied by heat, and the ignition and explosion of the battery may be caused.

Further, the gas generated inside the battery cell may induce a structural deformation of the electrode, such as a twist, to further promote the reaction between the electrode material and the electrolyte.

This deterioration is more serious in a pouch-shaped battery cell using a laminate sheet as a battery case. Specifically, since the pouch-shaped battery case of the laminate sheet contains a large amount of the low-thermal-conductivity polymer material, cooling by heat conduction is not easy, and heat may accumulate from inside the battery cell and eventually lead to severe deterioration.

Accordingly, there is a high need for a technique for a pouch-shaped battery cell that can secure safety against deterioration due to overcharging and overcharging. On the other hand, there is a specific example of the technology as a background of the present invention, as disclosed in patent document KR10-2014-0040327 A (publication date: Apr. 04, 2014).

KR 10-2014-0040327 A

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.

The inventors of the present application have conducted intensive research and various experiments. As described later, when the inner pressure of the battery cell rises due to overcharging, the lead assembly which is lost its power supply function is constituted by the electrode lead of the pouch type battery cell , The safety of the battery cell can be greatly improved, and the present invention has been accomplished.

According to an aspect of the present invention, there is provided a lid assembly comprising:

A lead assembly constituting an electrode lead of a pouch type battery cell,

A first lead having a plate shape made of an electrically conductive metal;

A second lead electrically connected to the electrode tabs of the battery cell;

A third lead between the first lead and the second lead, one side of which is electrically connected to the first lead and the other side of which is electrically connected to the second lead;

A first housing which accommodates at least a part of the third lead on one side and mechanically engages with the second lead on the other side; And

A second housing formed with grooves into which at least a part of the first lead and the third lead are inserted and fixed, and mechanically fastened to the first housing with the first lead and the third lead inserted therein;

, ≪ / RTI >

The electrical connection between the second lead and the third lead is broken when the internal pressure of the battery cell rises.

That is, the lead assembly of the present invention has a structure in which the first, second and third leads are electrically connected to each other. When the internal pressure of the battery cell increases due to overcharging, the second lead and the third lead The electrical connection is cut off and the energizing function of the lead assembly is lost, thereby preventing charging or discharging of the battery cell through the lead assembly.

The third lead of the present invention may have a special structure in which the shape is deformed in accordance with an increase in internal pressure of the battery cell.

Specifically, the third lead includes: a first plate portion joined to a first surface of a first lead of a plate-like shape;

A second plate portion joined to a second surface of the first lead, which is an opposite surface of the first surface;

A deformable portion connecting the first plate portion and the second plate portion and protruding and extending in the second lead direction while increasing the inclination gradually from both end portions to the center portion; And

And a third plate portion located at the center of the variable portion and welded or soldered for electrical connection with the second lead.

In this case, the third lead may be deformed by a pressure in the form of a deformable portion protruding from the third lead, and may break a part of the second lead when deformed.

The second lead being coupled to the other surface of the first housing and being welded or soldered to the third plate portion;

An extension extending from an upper end or a lower end of the coupling portion and bent to be horizontal with respect to the coupling portion; And

A fused portion extending from the extended portion so as to be perpendicular to the coupling portion, the fused portion being welded to the electrode tab of the battery cell;

. ≪ / RTI >

Wherein a plurality of openings are formed in the coupling portion so that a gas generated in the battery cell passes therethrough and pressure is applied to the variable portion of the third lead, And a connection end which is welded or soldered in a surface contact state and can be broken when the internal pressure of the battery cell rises is formed.

The connecting end can be easily broken in response to the deforming force of the deformable part when the deformable part is deformed by the pressure. In detail, the connecting part can be easily broken at the remaining part except for the part where the third plate part is welded or soldered. A plurality of notches or through-holes may be formed.

As described above, the lead assembly according to the present invention including the first lead, the second lead, and the third lead, when the internal pressure of the battery cell rises, becomes gradually gentle due to the variable additional pressure, A deformation to move in the lead direction occurs, and the third plate portion moves by the deformation of the deformable portion to tear off the connection end from the engagement portion. Therefore, when the internal pressure of the battery cell rises abruptly due to overcharging, the third lead may be disconnected from the second lead, thereby losing the function of energizing the lead assembly.

As described above, the lead assembly according to the present invention can lose its power supply function in response to an increase in the pressure inside the battery cell due to charging / discharging or overcharging, thereby shutting off the current to the battery cell via the lead assembly Serious safety problems such as explosion due to deterioration or deterioration of a serious battery cell can be prevented in advance.

Meanwhile, in the lid assembly according to the present invention, the first housing and the second housing have a special structure for receiving and fixing the first, second, and third leads.

In one specific example, the first housing has a depressed groove which can receive the variable portion of the third lead, and the third plate of the third lead is mounted on the other surface of the first housing, An opening may be formed so as to be in contact with the engaging portion of the second lead.

Therefore, the third plate portion and the engaging portion are in contact with each other through the opening of the first housing.

The first housing may also be provided with one or more through holes communicating therewith at positions corresponding to the openings of the engaging portion, so that the gas generated inside the battery cell is discharged through the openings in the engaging portion of the second lead And the through hole of the first housing in order to apply pressure to the variable portion of the third lead.

A sealing member may be added to the indentation groove so as to prevent gas from flowing out to other portions except for the opening and the through-hole. Specifically, a ring-shaped sealing member may be mounted on the indentation groove. The sealing member seals the interface between the third lead and the recessed groove of the housing to prevent gas from flowing out to the interface. Thus, the gas inside the battery cell can be concentrated in the variable portion of the third lead through the opening and the through-hole.

The first housing and the second lead may be mechanically coupled to each other. To this end, the first housing and the second lead may have mutually engageable structures.

Specifically, a plurality of fastening protrusions are formed on the other surface of the first housing, and a plurality of fastening recesses for engaging the fastening protrusions are formed on the fastening protrusions at positions corresponding to the fastening protrusions. The fastening protrusions may have a rivet structure having a larger diameter than the fastening recesses.

In addition, the first housing and the coupling portion may be coupled to each other by ultrasonic joining. The ultrasonic welding is performed at the interface where the first housing and the coupling part are in close contact with each other, so that these surfaces can be firmly bonded to each other. In some cases, the fastening protrusions and the fastening groove parts which are engaged with each other can also be ultrasonic welded.

In one specific example, the second housing comprises:

A first groove into which a first lead is inserted; And

And a pair of second grooves communicating with the thickness direction of the second housing so as to be led out in the first lead direction with the first and second plate portions of the third lead inserted.

Here, the first groove may be formed at a depth of 50% to 70% with respect to the thickness of the second housing, and the first lead may be inserted into the first housing with one end of the first lead inserted into the first groove .

The first groove may be formed at a central portion of the first housing at a length corresponding to the width of the first lead, and the second grooves may be formed at upper and lower portions with respect to the first groove.

In this case, the first plate portion and the second plate portion are bent in the first lead direction so as to be in close contact with the upper surface and the lower surface of the first lead, respectively, while being protruded from the second grooves, The plate portions may each be welded or soldered to the upper and lower surfaces of the first lead.

Accordingly, the first lead is electrically connected to the first plate portion and the second plate portion, and is fixed by the first groove of the first housing and the first plate portion and the second plate portion.

The second housing may further include a support portion which is in close contact with and supports at least a part of the variable portion, and the support portion may have a structure in which at least two or more support portions are formed on one surface facing the first housing.

At least a portion of the variable portion may be a portion that is not inclined in the variable portion, specifically, the ends of the variable portion. When the third lead is fixed in the indentation groove of the first housing and the pressure is applied to the deformable portion in the first lead direction, the support portion supports the end portion of the deformable portion while closely contacting the end portions of the deformable portion, And the adjacent variable shape is easily deformed. The supporting portions may also be equipped with a ring-shaped sealing member.

The second housing has a protrusion protruding outward on a surface facing the first housing, and a first housing having a position corresponding to the protrusion is formed with a coupling groove into which the protrusion can be inserted. .

In addition, a screw thread is formed on the inner surface of the protrusion and the coupling groove, and the first housing and the second housing can be coupled by the screw.

An insulating film may be added to outer surfaces of the first and second housings.

The insulating film may include an inner adhesive surface attached to an outer surface of the first housing and the second housing, and an outer adhesive surface thermally adhered together with an inner surface of the battery case.

The inner bonding surface or the outer bonding surface may include at least one selected from the group consisting of, for example, polypropylene, a polypropylene copolymer and a modified polypropylene, but is not limited thereto.

In one specific example, each of the first lead, the second lead, and the third lead may be made of an electrically conductive material. In detail, the first lead, the second lead, and the third lead may be at least one selected from lead, copper, tin and aluminum, It is not.

The first housing and the second housing may be made of an electrically insulating polymer, and the sealing member may include an elastic material, and in particular, it may be rubber or silicone, but is not limited thereto.

The present invention also provides a battery cell including the lead assembly.

The battery cell includes a structure in which two or more unit cells each including at least one anode, a cathode, and a separator are wound in a state where they are arranged in a separation film, or a structure in which a plurality of anodes, a separator, and a cathode are sequentially stacked And a battery case, which is a laminate sheet including a resin layer and a metal layer, together with an electrolytic solution.

The lead assembly may be coupled to the electrode tabs formed on the electrodes of the electrode assembly by welding or soldering. Specifically, the lead assembly may have a structure in which the fused portion is coupled to the electrode tabs in the second lead of the lead assembly.

Thus, the lead assembly can be housed in the battery case in a state of being coupled with the electrode assembly.

The battery cell having such a structure may have a structure in which the first housing and the second housing are located on the outer circumferential surface of the battery case and the outer circumferential surface of the battery case is thermally fused and sealed while the first lead protrudes to the outside.

The battery cell according to the present invention is not particularly limited in its kind, but specific examples thereof include a lithium ion (Li-ion) secondary battery having advantages of high energy density, discharge voltage and output stability, a lithium polymer (Li- polymer secondary battery, a lithium-ion polymer secondary battery, or the like.

Generally, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt.

The positive electrode is prepared, for example, by coating a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector, and then drying the mixture. Optionally, a filler may be further added to the mixture.

The cathode current collector is generally made to have a thickness of 3 to 500 micrometers. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery, and may be formed of a material such as stainless steel, aluminum, nickel, titanium, sintered carbon, or a surface of aluminum or stainless steel Treated with carbon, nickel, titanium, silver or the like may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like. However, the present invention is not limited to these.

The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component which assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for suppressing the expansion of the anode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. Examples of the filler include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The negative electrode is manufactured by applying and drying a negative electrode active material on a negative electrode collector, and if necessary, the above-described components may be selectively included.

The negative electrode collector is generally made to have a thickness of 3 to 500 micrometers. Such an anode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery, and may be formed of a material such as copper, stainless steel, aluminum, nickel, titanium, fired carbon, surface of copper or stainless steel A surface treated with carbon, nickel, titanium, silver or the like, an aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

Examples of the negative electrode active material include carbon such as non-graphitized carbon and graphite carbon; _{Li x Fe 2 O 3 (0≤x≤1} ), Li x WO 2 (0≤x≤1), Sn x Me 1-x Me 'y O z (Me: Mn, Fe, Pb, Ge; Me' : Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen, 0 < x < Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The separation membrane is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the membrane is generally 0.01 to 10 micrometers, and the thickness is generally 5 to 300 micrometers. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

The electrolytic solution may be a non-aqueous electrolytic solution containing a lithium salt, and is composed of a non-aqueous electrolytic solution and a lithium salt. As the non-aqueous electrolyte, non-aqueous organic solvents, organic solid electrolytes, inorganic solid electrolytes, and the like are used, but the present invention is not limited thereto.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyrolactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane , Acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate Nonionic organic solvents such as tetrahydrofuran derivatives, ethers, methyl pyrophosphate, ethyl propionate and the like can be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, Polymers containing ionic dissociation groups, and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

For the purpose of improving the charge-discharge characteristics and the flame retardancy, the nonaqueous electrolytic solution is preferably a solution prepared by dissolving or dispersing in a solvent such as pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, hexaphosphoric triamide, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like may be added have. In some cases, halogen-containing solvents such as carbon tetrachloride and ethylene trifluoride may be further added to impart nonflammability. In order to improve the high-temperature storage characteristics, carbon dioxide gas may be further added. FEC (Fluoro-Ethylene Carbonate, PRS (Propene sultone), and the like.

In one specific _{example, LiPF 6, LiClO 4, LiBF} 4, LiN (SO 2 CF 3) 2 , such as a lithium salt, a highly dielectric solvent of DEC, DMC or EMC Fig solvent cyclic carbonate and a low viscosity of the EC or PC of And then adding it to a mixed solvent of linear carbonate to prepare a lithium salt-containing non-aqueous electrolyte.

 The present invention also provides a battery pack including at least one battery cell, and a device including the battery pack.

As described above, the lead assembly according to the present invention has a structure in which the first, second, and third leads are electrically connected to each other. When the internal pressure of the battery cell increases due to overcharging, The electrical connection between the second lead and the third lead is cut off, and consequently, the power supply function of the lead assembly is lost, thereby preventing the battery cell from being charged or discharged through the lead assembly.

Also, even if the internal pressure of the battery cell increases due to overcharging or overcharging, the lead assembly loses its function of energizing the battery cell according to the present invention, so that the deterioration of the battery cell due to overcharging, Can be prevented.

1 is an exploded perspective view of a lid assembly according to the present invention;
Figures 2 and 3 are schematic diagrams of a third lead of the lid assembly;
4 is a schematic diagram of a second lead of the lid assembly;
5 is a schematic view of a structure in which a first housing and a second lead are coupled;
Figs. 6 and 7 are schematic diagrams of a structure in which a first housing and a third lead are combined; Fig.
8 is a schematic diagram of a structure in which a first housing and a second housing are coupled together;
9 is a schematic view of a first housing and a second housing that have been combined;
10 is a schematic diagram of a lid assembly that has been assembled;
11 is a vertical cross-sectional view of the lid assembly;
12 is an enlarged schematic view of a portion A in Fig. 11; Fig.
13 is a schematic view of a structure in which a lead assembly and an electrode assembly are combined in a battery cell according to the present invention;
14 is a schematic view of a battery cell according to the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings according to embodiments of the present invention, but the scope of the present invention is not limited thereto.

1 is an exploded perspective view of a lid assembly 100 according to the present invention.

Referring to FIG. 1, the lead assembly 100 includes a first lead 110 having a plate-like shape made of an electrically conductive metal, a second lead 120 connected to the electrode tabs of the battery cell and made of an electrically conductive metal, A third lead 130 electrically connected at one side to the first lead 110 and electrically connected to the second lead 120 at the other side between the first lead 110 and the second lead 120, At least a part of the first housing 140, the first lead 110 and the third lead 130, which accommodates at least a part of the lead 130 on one side and mechanically fastens the second lead 120 on the other side, A second housing 150 formed with grooves to be inserted and fixed and mechanically fastened to the first housing 140 in a state where the first and second leads 110 and 130 are inserted, And an insulating film 170 surrounding the members 160a and 160b and the outer surfaces of the first housing 140 and the second housing 150 .

The lid assembly 100 has a structure in which the lid assembly 100 is assembled and assembled as described below. In the following, the detailed structure and assembly process of each structure of the lid assembly 100 will be described in detail.

2 and 3, a third lead 130 of the lid assembly 100 is schematically illustrated.

Referring to these drawings, the third lead 130 connects the first plate portion 132, the second plate portion 134, the first plate portion 132 and the second plate portion 134, And a third plate portion 138 positioned at a center portion of the variable portion 136. The first plate portion 138 and the second plate portion 138 are formed of a metal plate.

Here, the third plate portion 138 is welded or soldered to a part of the second lead 120 for electrical connection with the second lead 120, and the first plate portion 132 and the second plate portion 134 are joined to the first lead 110 of the plate-like shape by welding or soldering.

The variable portion 136 of the third lead 130 can be deformed from the initial shape in such a manner that the inclination of the variable portion 136 becomes gentle when the pressure is applied.

FIG. 4 shows a schematic view of the second lead 120 of the lid assembly 100.

4, the second lead 120 includes a coupling portion 122 coupled to the first housing 140 and welded or soldered to the third plate portion 138 at the third lead 130, And extends from the upper end or the lower end of the engaging portion 122 and extends from the extending portion 126 so as to be perpendicular to the engaging portion 122 and the extending portion 126 bent to be horizontal with respect to the engaging portion 122. [ And a fused portion 128 welded to and joined to the electrode tab of the battery cell.

A plurality of openings 129 are formed in the coupling part 122 so that gas generated in the battery cell can pass therethrough and a pressure can be applied to the variable part 136 of the third lead 130.

The engaging portion 122 is welded or soldered to the third plate portion 138 in a surface-contacting state at a position facing the third plate portion 138, and can be broken when the internal pressure of the battery cell rises A connecting end 124 is formed.

The connecting end 124 is formed with through holes 124b in other portions except for the portion 124a to be joined to the third plate portion 138 so that the connecting end 124 can be easily broken when an external force is applied.

The engaging portion 122 is also formed with a plurality of engaging grooves 123a and 123b to enable mechanical engaging with the first housing 140. [

Hereinafter, the coupling structure of the first housing 140, the second lead 120, and the third lead 130 will be described in detail.

5 schematically illustrates the coupling structure of the first housing 140 and the second lead 120. In FIGS. 6 and 7, the coupling structure of the first housing 140 and the third lead 130 is Are schematically shown.

Referring to these drawings, a depression groove 146 is formed in a first surface of the first housing 140 so as to receive the variable portion 136 of the third lead 130, A coupling groove 148 for coupling with the second housing 150 is formed.

An opening (not shown) is formed in the indentation groove 146 so that the third plate portion 138 of the third lead 130 can be exposed in the other surface direction of the first housing 140. Accordingly, the third plate portion 138 can contact the engaging portion 122 of the second lead 120 mounted on the other surface of the first housing 140.

A plurality of fastening protrusions 143a and 143b are formed on the other surface of the first housing 140. These fastening protrusions 143a and 143b are larger than the fastening grooves 123a and 123b of the fastening portion 122 Diameter rivet structure.

Accordingly, the first housing 140 is fastened to the fastening protrusions 143a and 143b of the fastening protrusions 143a and 143b of the fastening protrusions 143a and 143b of the fastening protrusions 143a and 143b, 123a, and 123b, respectively, so that mechanical fastening can be achieved.

Ultrasonic joining can be performed on the interface between the first housing 140 and the coupling part 122 so that the first housing 140 and the coupling part 122 Are tightly bonded to each other. In some cases, the fastening protrusions 143a and 143b and the fastening grooves 123a and 123b, which are engaged with each other, may be ultrasonically fused.

The connection end of the second lead 120 is in electrical contact with the third plate portion 138 of the third lead 130 exposed through the opening of the first housing 140, They are combined.

That is, the third plate portion 138 and the connecting end are mechanically and electrically connected to each other through the opening of the housing.

The first housing 140 is also formed with a plurality of through-holes 144 communicating with the openings of the engaging portion 122 at positions corresponding to the openings. A ring-shaped sealing member 160a is inserted into the indentation groove 146 and the third lead 130 is mounted in the indentation groove 146 with the sealing member 160a inserted. The third lead 130 is mounted on the indentation groove 146 with the first plate portion 132 and the second plate portion 134 exposed to the outside of the indentation groove 146, The member 160b is inserted into the indentation groove 146 in such a manner as to surround the first plate portion 132 and the second plate portion 134. [

The sealing member 160b may also be mounted on a support portion (see 156 in Fig. 11) formed in the second housing 150 when the first housing 140 and the second housing 150 are engaged.

The sealing members 160a and 160b prevent gas from flowing out to the interfaces at which the third leads 130 and the indentation grooves 146 of the first housing 140 are in contact with each other, The gas may flow through the openings 129 of the engagement portion 122 and the through openings 144 of the first housing and may be concentrated on the variable portion 136 of the third lead 130. [

More specifically, a surplus space (see 190 in FIG. 12) is formed inside the indentation groove 146 and the variable portion 136 mounted on the indentation groove 146, Is sealed from the outside by the sealing members (160a, 160b) except for the through hole (144) of the first housing (140) and the first housing (129).

Therefore, when gas is generated in the battery cell, the gas passes through the opening 129 formed in the engaging portion 122 of the second lead 120 and the through hole 144 of the first housing 140 in order, The pressure can be intensively applied to the variable portion 136 of the three leads 130. [

FIG. 8 shows a coupling structure of the first housing 140 and the second housing 150, and FIG. 9 schematically illustrates the first housing 140 and the second housing 150, which are completely combined.

8, the second housing 150 includes a first groove 153 into which the first lead 110 is inserted and a second groove 153 through which the first plate portion 132 and the second plate 132 of the third lead 130 are inserted. And a pair of second grooves 152a and 152b communicating with each other in the thickness direction of the second housing 150 so as to be led out toward the first lead 110 in a state where the plate portion 134 is inserted .

The second grooves 152a and 152b are spaced apart from each other at the top and the bottom with respect to the first groove 153. The first plate portion 132 and the second plate portion 134 are spaced apart from the second grooves 152a The first housing 140 and the second housing 150 are inserted into the first and second housings 150 and 152b and then protruded outward from the second housing 150 as shown in FIG.

The second housing 150 is formed with a protrusion 154 protruding outward on one surface thereof facing the first housing 140. The protrusion 154 protrudes from the first housing 140 And are coupled to each other.

The coupling may be a screw coupling as an example. Specifically, the protrusion 154 may be configured to communicate with the first housing 140 from the first side of the second housing 150, A thread is formed on the inner surface of the projection 154 and the coupling groove 148 so that the screw can be engaged with the projection 154. When the projection 154 is inserted into the coupling groove 148, And the first housing 140 and the second housing 150 are coupled to each other.

Alternatively, the protrusion 154 may have a rivet structure having a larger diameter than the coupling hop 148, and the coupling may be such that the first housing 140 and the second housing 150 face each other , The protrusion 154 formed at the corresponding position may be engaged with the coupling groove 148 to achieve mechanical fastening to each other.

The first housing 140 and the second housing 150 are coupled to each other at a joint end portion formed on the outer surface of the first housing 140 and the second housing 150, Can be further applied.

An insulating film 170 may be attached to the outer surfaces of the first housing 140 and the second housing 150 with the above-described coupling structure, and the insulating film 170 may be formed on the outer surface of the first housing 140 and the second housing 150, And can be thermally fused together with the outer peripheral portion in a state of being inserted into the outer peripheral portion of the case.

FIG. 10 is a schematic view of a assembled lid assembly 100, and FIG. 11 is a vertical cross-sectional view of the lid assembly 100.

Referring to FIG. 11 and FIGS. 8 and 9, the second housing 150 includes a first housing 140 and a second housing 150. The second housing 150 includes a first housing 140, And a single-phase supporting portion 156 for supporting the single-phase supporting portion 156 is formed.

The support portion 156 is fixed to the end portions of the variable portion 136 so that the third lead 130 is fixed in the indentation groove 146 of the first housing 140 and the second lead 130 is fixed in the direction of the first lead 110 When the pressure is applied to the variable portion 136, the end of the variable portion 136 is supported, and the variable portion 136 adjacent to the third plate portion 138 is easily deformed.

Referring to FIG. 10 together with FIGS. 8 and 9, the first lead 110 is fixed to the first housing 140 with one end of the first lead 110 inserted into the first groove, The first plate portion 132 and the second plate portion 134 of the third lead 130 protruding from the second grooves of the first lead 110 and the second lead portion 130 are in close contact with the upper surface and the lower surface of the first lead 110, The first plate portion 132 and the second plate portion 134 are welded to the upper surface and the lower surface of the first lead 110, respectively.

1 to 11, a lead assembly 100 according to the present invention includes a first lead 110, a second lead 120, and a third lead 130, which are electrode leads, And the deformable portion 136 of the third lead 130 is deformed to deform the first lead 110 and the second lead 150 in the abnormal state of the battery cell, And electrically disconnects the second lead 120 and the third lead 130 from each other.

Referring to FIG. 12, if a large amount of gas is generated in the battery cell and the internal pressure rises, the pressure of the gas flowing through the opening of the coupling part 122 and the through hole of the first housing 140 The variable section 136 is deformed toward the first lead 110 and the inclination becomes gentle. At this time, when deformation of the variable portion 136 continues and the deformation force of the variable portion 136 is equal to or higher than the coupling force between the connection end 124a and the engagement portion 122 (dotted line in FIG. 12), the connection end 124a ' And moves in the direction of the first lead 110 together with the third plate portion 138 which is completely broken from the coupling portion 122 and coupled to each other.

Accordingly, the electrical connection between the third lead 130 and the second lead 120 is lost, and as a result, the first lead 110 connected to the third lead 130 is short-circuited.

Accordingly, the lead assembly 100 according to the present invention can lose the power supply function corresponding to the increase in the pressure inside the battery cell due to charge / discharge or overcharging, It is possible to prevent a safety problem such as an explosion due to deterioration and deterioration of the battery cell.

Fig. 13 schematically shows the coupling structure of the lead assembly 100 and the electrode assembly, and Fig. 14 schematically shows the battery cell according to the present invention.

Referring to these figures, a battery cell 200 is formed in a state where a plurality of electrode tabs 212 formed on an electrode assembly 210 are connected to a fused portion 128 of a second lead 120 from a lead assembly 100, And is housed together with an electrolyte in a pouch-shaped battery case 220 that can be sealed by fusing.

A lead assembly 100 protrudes from one end of the battery cell 200 and an electrode lead 214 protrudes from the other end of the battery cell 200 in an opposite polarity to the lead assembly 100.

The lead assembly 100 includes a first housing 140 and a second housing 150 to which the insulating film 170 is attached and a first lead 110 positioned on one side of the outer circumferential surface of the battery case 220, And is thermally fused together with the outer circumferential surface of the battery case 220. [

Although FIG. 14 shows the single lead assembly 100 as an electrode lead of the battery cell 200, it is needless to say that the pair of lead assemblies 100 can be constituted of the positive electrode lead and the negative electrode lead of the battery cell.

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 (24)

A lead assembly constituting an electrode lead of a pouch type battery cell,
A first lead having a plate shape made of an electrically conductive metal;
A second lead electrically connected to the electrode tabs of the battery cell;
A third lead between the first lead and the second lead, one side of which is electrically connected to the first lead and the other side of which is electrically connected to the second lead;
A first housing which accommodates at least a part of the third lead on one side and mechanically engages with the second lead on the other side; And
A second housing formed with grooves into which at least a part of the first lead and the third lead are inserted and fixed, and mechanically fastened to the first housing with the first lead and the third lead inserted therein;
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The electrical connection portion between the second lead and the third lead is broken when the internal pressure of the battery cell rises,
The other surface of the first housing is in close contact with the second lead while the electrical connection portion between the second lead and the third lead is mechanically and electrically connected through the opening of the other surface of the first housing. Lead assembly. The semiconductor device according to claim 1,
A first plate portion joined to the first surface of the first lead of the plate-like shape;
A second plate portion joined to a second surface of the first lead, which is an opposite surface of the first surface;
A deformable portion connecting the first plate portion and the second plate portion and protruding and extending in the second lead direction while increasing the inclination gradually from both end portions to the center portion; And
A third plate portion located at the center of the variable portion and welded or soldered for electrical connection with the second lead;
Wherein the lead assembly comprises: 3. The semiconductor device according to claim 2,
An engaging portion welded or soldered to the third plate portion while being coupled to the other surface of the first housing;
An extension extending from an upper end or a lower end of the coupling portion and bent to be horizontal with respect to the coupling portion; And
A fused portion extending from the extended portion so as to be perpendicular to the coupling portion, the fused portion being welded to the electrode tab of the battery cell;
Wherein the lead assembly comprises: 4. The battery pack according to claim 3, wherein a plurality of openings are drilled in the coupling portion, and are welded or soldered to the third plate portion at a position facing the third plate portion, and when the internal pressure of the battery cell rises Wherein a connecting end is formed which can be broken. The lid assembly according to claim 4, wherein the connecting end is formed with a plurality of notches or through-holes in the remaining portion except the portion where the third plate portion is welded or soldered. The battery pack according to any one of claims 2 to 5, wherein when the internal pressure of the battery cell rises, the variable portion is deformed toward the first lead as the inclination becomes gentle by the pressure, and the third plate portion deforms And the connecting end is ruptured and separated from the engaging portion. 6. The connector according to any one of claims 1 to 5, wherein a depressed groove capable of accommodating a variable portion of a third lead is formed on one surface of the first housing, and a third plate portion of the third lead And an opening is formed so as to be in contact with the engaging portion of the second lead mounted on the other surface of the housing. The lid assembly of claim 7, wherein the first housing is formed with one or more through-holes communicating with the openings of the coupling portion at corresponding positions. 8. The lid assembly of claim 7, wherein the indentation groove is mounted with a ring-shaped sealing member. [8] The apparatus of claim 7, wherein a plurality of fastening protrusions are formed on the other surface of the first housing, and a plurality of fastening recesses for engaging the fastening protrusions are formed on the fastening protrusions at positions corresponding to the fastening protrusions Features a lid assembly. 11. The lid assembly of claim 10, wherein the first housing and the coupling portion are coupled to each other by ultrasonic joining. The connector according to any one of claims 1 to 5, wherein the second housing comprises:
A first groove into which a first lead is inserted; And
A pair of second grooves communicating with the thickness direction of the second housing so as to be led out in the first lead direction with the first and second plate portions of the third lead inserted;
Wherein the lead assembly comprises: 13. The lid assembly of claim 12, wherein the first groove is formed at a depth of 50% to 70% based on the thickness of the second housing. 13. The electronic device of claim 12, wherein the first groove is formed at a central portion of the first housing with a length corresponding to the width of the first lead, and the second grooves are formed at upper and lower portions with respect to the first groove Wherein the lead assembly is made of a metal. 13. The apparatus of claim 12, wherein the first plate portion and the second plate portion are respectively bent in a first lead direction so as to be in close contact with the upper surface and the lower surface of the first lead in a state of protruding from the second grooves, And the second plate portion are welded or soldered to the upper surface and the lower surface of the first lead, respectively. 13. The lid assembly as claimed in claim 12, wherein the second housing includes a support portion which is in close contact with and supports at least a part of the variable portion, and at least two or more support portions are formed on one surface of the first housing facing the first housing. 17. The lid assembly of claim 16, wherein the support portions are mounted with a ring-shaped sealing member. [2] The apparatus according to claim 1, wherein the second housing has protrusions protruding outward on one surface thereof facing the first housing, and the protrusions can be inserted into one surface of the first housing at a position corresponding to the protrusions And a coupling groove is formed in the coupling member. 19. The lid assembly of claim 18, wherein a thread is formed on an inner surface of the protrusion and the coupling groove, and the first housing and the second housing are coupled by the screw. The lid assembly according to claim 1, wherein an insulating film is attached to outer surfaces of the first housing and the second housing. A battery cell comprising the lead assembly according to claim 1,
A structure in which two or more unit cells each including at least one anode, a cathode, and a separator are wound in a state of being arranged in a separation film, or an electrode assembly having a structure in which a plurality of anodes, a separator and a cathode are sequentially stacked, , And the battery cell is housed in a pouch-shaped battery case which is a laminate sheet including a resin layer and a metal layer. The battery cell according to claim 21, wherein the battery cell has a structure in which the first housing and the second housing are located on the outer circumferential surface of the battery case and the outer circumferential surface of the battery case is thermally fused and sealed with the first lead protruding outward . A battery pack comprising at least one battery cell according to claim 21. 26. A device comprising a battery pack according to claim 23.

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