KR102288097B1 - Pouch-typed Battery Cell Comprising Electrode Tab and Lead Having Current Breaking Function - Google Patents

Abstract

an electrode assembly having a structure in which a separator is interposed between the positive electrode, the negative electrode, and the positive electrode and the negative electrode; and a battery case in which a first electrode assembly accommodating part in which a part of the electrode assembly is embedded and a second electrode assembly accommodating part in which the remaining part of the electrode assembly is embedded are formed; including, and extending from the electrode plates of the electrode assembly In the electrode tabs, one end portion is coupled to the other end portion of the electrode lead protruding to the outside of the battery case, and due to expansion and deformation of the battery case when the internal pressure of the battery cell rises, at least one of the electrode tabs and the electrode lead One or the electrode tabs and the connection part of the electrode lead can be disconnected, (i) one surface of the electrode tabs facing the electrode lead and/or (ii) one surface of the electrode lead facing the electrode tabs is fused to the inner surface of the battery case It provides a battery cell, characterized in that the.

Description

{Pouch-typed Battery Cell Comprising Electrode Tab and Lead Having Current Breaking Function}

The present invention relates to a pouch-type battery cell including an electrode tab and a lead having a current blocking function.

With the dazzling development of IT (Information Technology) technology, the spread of various portable information and communication devices is taking place, and the 21st century is developing into a 'ubiquitous society' where high-quality information services are possible regardless of time and place.

A lithium secondary battery occupies an important position in the development basis for such a ubiquitous society. Specifically, a rechargeable lithium battery that can be charged and discharged is widely used as an energy source for wireless mobile devices, and it is proposed as a method to solve the air pollution of existing gasoline and diesel vehicles using fossil fuels. It is also used as an energy source for electric vehicles and hybrid electric vehicles.

As described above, as devices to which lithium secondary batteries are applied are diversified, lithium secondary batteries are being diversified to provide output and capacity suitable for the devices to which they are applied. In addition, there is a strong demand for miniaturization and thinning.

The above-described lithium secondary battery may be classified into a cylindrical battery cell, a prismatic battery cell, a pouch-type battery cell, and the like according to its shape. Among them, a pouch-type battery cell that can be stacked with a high degree of integration, has a high energy density per weight, is inexpensive, and is easy to deform, is attracting a lot of attention.

The pouch-type battery cell has a structure in which an electrode assembly having a positive electrode, a negative electrode, and a separator structure is embedded together with an electrolyte in a battery case of a laminate sheet, and the outer periphery of the battery case is heat-sealed and sealed.

In the case of a conventional pouch-type battery cell, when gas is continuously generated inside the battery cell due to overcurrent and overvoltage during charging and discharging, even if the sealing part on one side of the battery case is opened and the gas is discharged, there is no effect on the electrode assembly through which current flows. Therefore, charging and discharging current continuously flows through the electrode assembly, causing continuous gas generation, and the gas leaks to the outside and has a harmful effect on the human body, and may cause ignition and explosion due to the temperature increase of the battery.

Therefore, there is a great need for a battery cell capable of solving the above problems.

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

An object of the present invention is to provide a battery cell capable of ensuring safety by blocking the current flowing through the battery so as to prevent the gas generated inside the battery from being continuously discharged during abnormal operation of the battery.

The battery cell according to the present invention for achieving this object,

an electrode assembly having a structure in which a separator is interposed between the positive electrode, the negative electrode, and the positive electrode and the negative electrode; and

a battery case in which a first electrode assembly accommodating part in which a part of the electrode assembly is embedded and a second electrode assembly accommodating part in which the remaining part of the electrode assembly is embedded;

contains,

The electrode tabs extending from the electrode plates of the electrode assembly are coupled to the other end portion of the electrode lead from which one end portion protrudes to the outside of the battery case,

At least one of the electrode tabs and the electrode lead, or the connection portion of the electrode tabs and the electrode lead, by the expansion deformation of the battery case when the internal pressure of the battery cell rises, (i) one surface of the electrode tabs facing the electrode lead and / or (ii) one surface of the electrode lead facing the electrode tabs may have a structure that is fused to the inner surface of the battery case.

Therefore, since the battery cell according to the present invention has a structure in which one surface of the electrode tabs facing the electrode leads and/or one surface of the electrode lead facing the electrode tabs is fused to the inner surface of the battery case, the internal pressure of the battery cell increases Due to the expansion deformation of the battery case, at least one of the electrode tabs and the electrode lead, or the connection portion between the electrode tabs and the electrode lead is cut off to prevent continuous gas generation, thereby ensuring safety.

In one embodiment of the present invention, the connection part of the electrode tab and the electrode lead may have a structure located on the unsealed part between the electrode assembly accommodating part and the sealing part formed on the outer periphery of the electrode assembly accommodating part. there is.

In one specific example of the present invention, the battery case consists of a first case member and a second case member;

the first electrode assembly accommodating part is formed on a first case member, and the second electrode assembly accommodating part is formed on a second case member;

surfaces of the electrode tabs facing the electrode lead are fused to the inner surface of the first case member;

One surface of the electrode lead facing the electrode tabs may have a structure that is fused to the inner surface of the second case member.

In addition, the bonding strength between the electrode tabs and the electrode lead in the connection part may be relatively smaller than the fusion strength between the electrode tabs and the battery case or the fusion strength between the electrode lead and the battery case. Accordingly, when the battery case is expanded and deformed, the connection portion between the electrode tabs and the electrode lead may be disconnected prior to being disconnected between the electrode tabs and the battery case or between the electrode lead and the battery case.

Specifically, the bonding strength between the electrode tabs and the electrode lead in the connection part may be 50% to 99% of the fusion strength between the electrode tabs and the battery case or between the electrode lead and the battery case. When the bonding strength between the electrode tabs and the electrode lead is less than 50% of the fusion strength between the electrode tabs and the battery case or between the electrode lead and the battery case, the electrode is not only subjected to expansion and deformation of the battery case, but also to external shocks and vibrations. There may be a problem in that the connection between the tabs and the electrode lead is cut off.

On the other hand, when the bonding strength of the electrode tabs and the electrode lead exceeds 90% of the fusion strength between the electrode tabs and the battery case or between the electrode lead and the battery case, despite the expansion deformation of the battery case, There may be a problem that the connection between the electrode tabs and the electrode lead is not disconnected.

In addition, the rupture strength of the electrode tabs may be relatively smaller than the fusion strength between the electrode tabs and the battery case or the fusion strength between the electrode lead and the battery case. Accordingly, during the expansion deformation of the battery case, a portion of the electrode tab may be ruptured prior to between the electrode tabs and the battery case or between the electrode lead and the battery case, thereby causing power failure.

In addition, the rupture strength of the electrode lead may be relatively smaller than the fusion strength between the electrode tabs and the battery case or the fusion strength between the electrode lead and the battery case. Accordingly, during the expansion deformation of the battery case, a portion of the electrode tab may be ruptured prior to between the electrode tabs and the battery case or between the electrode lead and the battery case, thereby causing power failure.

In one embodiment of the present invention, the electrode tabs and the electrode lead may be coupled by ultrasonic welding. Ultrasonic welding forms a predetermined pattern on a welding surface, so that when the following heat-sealable film is fused to an electrode tab or an electrode lead, the effect of increasing the fusion strength can be exerted.

Specifically, at least one of the electrode tabs and the electrode lead may have a pitch pattern formed on one surface to which ultrasonic welding is applied.

The pitch pattern may be a pattern having a concave-convex structure formed by a plurality of protrusions and grooves on a vertical cross-section.

In one embodiment of the present invention, a heat-sealable film between the electrode tabs and the battery case or between the electrode tabs and the battery case or between the electrode leads and the battery case to increase the adhesive strength between the electrode tabs and the battery case or between the electrode lead and the battery case This may be intervening.

Specifically, the heat-sealable film may be a polypropylene film, but is not limited thereto as long as it is a material capable of increasing the adhesive strength between the electrode tabs and the battery case or between the electrode lead and the battery case.

In one embodiment of the present invention, the positive electrode tabs and the negative electrode tabs may be formed in the same direction. When the positive electrode tabs and the negative electrode tabs are formed in the same direction, the positive electrode tabs can be cut off simply by expansion and deformation of the battery case in only one direction in which the electrode tabs are formed, so that the flow of current in the battery cell can be rapidly increased. can be blocked

In another embodiment of the present invention, the positive electrode tabs and the negative electrode tabs may be formed to face each other. When the positive electrode tabs and the negative electrode tabs are formed in opposite directions, the flow of current in the battery cell may be blocked even if the battery case expands and deforms in only one of the directions in which the positive electrode tabs and the negative electrode tabs are formed.

The battery case is a battery cell, characterized in that it consists of a laminate sheet comprising a resin outer layer, a barrier metal layer, and a heat-melting resin sealant layer.

The battery case may be made of a pouch-type case having a laminate structure including a metal layer and a resin layer.

As a specific example of the battery case, the battery case is composed of a laminate sheet including an excellent durable resin outer layer, a barrier metal layer, and a heat meltable resin sealant layer, and the resin sealant layers are thermally fused to each other. can

Since the resin outer layer has to have excellent resistance from the external environment, it is necessary to have a tensile strength and weather resistance of at least a predetermined level. In this aspect, polyethylene terephthalate (PET) and a stretched nylon film may be preferably used as the polymer resin of the outer resin layer.

Preferably, aluminum may be used for the barrier metal layer to exhibit a function of improving the strength of the battery case in addition to the function of preventing the inflow or leakage of foreign substances such as gas and moisture.

The resin sealant layer has heat-sealing properties (thermal adhesive properties), low hygroscopicity to suppress the penetration of the electrolyte, and a polyolefin-based resin that is not expanded or eroded by the electrolyte may be preferably used, and more Preferably, unstretched polypropylene (CPP) may be used.

The battery cell may be a lithium secondary battery, specifically, a lithium ion battery or a lithium ion polymer battery.

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

The positive electrode, for example, is prepared 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, and, if necessary, further adding a filler to the mixture.

The positive active material may _{include 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 Formula Li _1+x Mn _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , and LiMnO _{2 ;} 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 ;} Ni site-type lithium nickel oxide represented by the formula LiNi _1-x M _x O ₂ (wherein 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, Zn or Ta and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (where M = Fe, Co, lithium manganese composite oxide represented by 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; And the like Fe ₂ (MoO _{4) 3,} but is not limited to these.

The conductive material is typically added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive active material. Such a conductive material is not particularly limited as long as it has conductivity without causing a chemical change 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 fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskeys such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; A conductive material such as a polyphenylene derivative may be used.

The binder is a component that assists in bonding between the active material and the conductive material and bonding to the current collector, and is typically added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive 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 butyrene rubber, fluororubber, various copolymers, and the like.

The filler is optionally used as a component for inhibiting the expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. For example, an olipine-based polymer such as polyethylene or polypropylene; A fibrous material such as glass fiber or carbon fiber is used.

The negative electrode is manufactured by coating and drying the negative electrode active material on the negative electrode current collector, and if necessary, the above-described components may be optionally further included.

Examples of the negative electrode active material include carbon such as non-graphitizable carbon and graphitic 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 composite oxides such as Al, B, P, Si, elements of Groups 1, 2, and 3 of the periodic table, halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; lithium metal; lithium alloy; silicon-based alloys; tin-based alloys; 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 metal oxides such as _{Bi 2} O _{5 ;} conductive polymers such as polyacetylene; A Li-Co-Ni-based material or the like can be used.

The separator 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 separator is generally 0.01 to 10 μm, and the thickness is generally 5 to 300 μm. As such a separation membrane, For example, olefin polymers, such as chemical-resistant and hydrophobic polypropylene; A sheet or nonwoven fabric made of glass fiber or polyethylene is used. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as a separator.

The lithium salt-containing non-aqueous electrolyte consists of a polar organic electrolyte and a lithium salt. As the electrolyte, a non-aqueous liquid electrolyte, an organic solid electrolyte, an inorganic solid electrolyte, and the like are used.

Examples of the non-aqueous liquid electrolyte include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyl lactone, 1,2-dimethoxy ethane, tetrahydroxy franc, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane , acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, trimethoxy methane, dioxolane derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbo An aprotic organic solvent such as a nate derivative, a tetrahydrofuran derivative, an ether, methyl pyropionate, or ethyl propionate may be used.

Examples of the organic solid electrolyte include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphoric acid ester polymers, poly agitation lysine, polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, A polymer containing an ionic dissociation group or 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, sulfates, etc. of Li such as Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₂ S-SiS _{2 and the like may be used.}

The lithium salt is a material easily 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 there is.

In addition, for the purpose of improving charge/discharge characteristics, flame retardancy, etc. in the non-aqueous electrolyte, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric acid triamide , nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, aluminum trichloride, etc. may be added. may be In some cases, in order to impart incombustibility, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further included, and carbon dioxide gas may be further included to improve high-temperature storage characteristics.

The present invention also provides a battery pack including one or more of the battery cells.

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 wearable electronic device, a portable computer, a smart pad, a netbook, a light electronic vehicle (LEV), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device.

Since the structures of these devices and their manufacturing methods are known in the art, detailed description thereof will be omitted herein.

As described above, the battery cell according to the present invention has a structure in which one surface of the electrode tabs facing the electrode lead and/or one surface of the electrode lead facing the electrode tabs is fused to the inner surface of the battery case, so the battery When the internal pressure of the cell is increased, due to the expansion and deformation of the battery case, at least one of the electrode tabs and the electrode lead, or the connection portion between the electrode tabs and the electrode lead is cut off to prevent continuous gas generation, thereby ensuring safety.

1 is a side perspective view of a battery cell according to an embodiment of the present invention;
FIG. 2 is a side perspective view of the battery cell of FIG. 1 in a state in which the battery case is expanded and deformed due to an increase in internal pressure, so that the connection between the electrode tabs and the electrode lead is disconnected;
3 is a side perspective view of the battery cell according to one embodiment of the present invention in a state in which the battery case is expanded and deformed in both directions due to an increase in internal pressure, so that the connection between the electrode tabs and the electrode lead is disconnected.

Hereinafter, although described with reference to the drawings according to the embodiment of the present invention, this is for easier understanding of the present invention, and the scope of the present invention is not limited thereto.

1 is a schematic side perspective view of a battery cell according to an embodiment of the present invention.

Referring to FIG. 1 , the battery cell 100 includes an electrode assembly 110 and a battery case 120 .

The electrode assembly 110 has a structure in which an anode, a cathode, and a separator are interposed between the anode and the cathode.

The battery case 120 includes a first case member 123 and a second case member 124, and the first case member 123 includes a first electrode assembly receiving part ( 121) is formed, and the second electrode assembly accommodating part 122 in which the remaining part of the electrode assembly 110 is embedded is formed in the second case member 124 .

The electrode tabs 130 extending in the same direction from the electrode plates 111 of the electrode assembly 110 are ultrasonically welded to the other end of the electrode lead 140 with one end protruding to the outside of the battery case 120 . are joined by A pitch pattern is formed on one surface to which ultrasonic welding is applied on the electrode tabs 130 and the electrode lead 140 .

At least one of the electrode tabs 130 and the electrode lead 140, or the electrode tabs 130 and the electrode lead 140 due to the expansion deformation of the battery case 120 when the internal pressure of the battery cell 100 is increased. The lower surfaces of the electrode tabs 130 facing the electrode lead 140 are fused to the inner surface of the first case member 123 so that the connection part 150 can be disconnected, and the electrodes facing the electrode tabs 130 are fused to the inner surface of the first case member 123 . The upper surface of the lead 140 is fused to the inner surface of the second case member 124 .

The connection part 150 of the electrode tab 130 and the electrode lead 140 is between the electrode assembly accommodating parts 121 and 122 and the sealing part 125 formed on the outer periphery of the electrode assembly accommodating parts 121 and 122 . It is located on the unsealed part.

The bonding strength between the electrode tabs 130 and the electrode lead 140 in the connection part 150 is the fusion strength between the electrode tabs 130 and the battery case 120 or the electrode lead 140 and the battery case 120 . It is relatively smaller than the strength of the fusion between them.

A heat-sealable film 160 is interposed between the electrode tabs 130 and the battery case 120 or between the electrode lead 140 and the battery case (!20) to increase fusion strength.

FIG. 2 schematically shows a side perspective view of the battery cell of FIG. 1 in a state in which the battery case is expanded and deformed due to an increase in internal pressure, and the connection portion between the electrode tabs and the electrode lead is disconnected.

Referring to FIG. 2 together with FIG. 1 , when the internal pressure of the battery cell 100 increases, the electrode fused to the first case member 123 by the expansion and deformation of the first case member 123 of the battery case 120 . The tabs 130 are cut in the downward direction (arrow direction) together with the first case member 123 member, so that the connection part 150 of the electrode tab 130 and the electrode lead 140 is cut off.

3 is a schematic side perspective view of a battery cell according to another embodiment of the present invention in which the battery case is expanded and deformed in both directions due to an increase in internal pressure and the connection between the electrode tabs and the electrode lead is disconnected. there is.

Referring to FIG. 3 , when the internal pressure of the battery cell 200 increases, the first case member 223 and the second case member 224 of the battery case 220 undergo expansion and deformation in both directions, the first case member The electrode tabs 230 fused to the 223 are cut in the downward direction (arrow direction) together with the first case member 223 member, and by the expansion deformation of the second case member 224 , the second case member The electrode lead 140 fused to the 224 is cut in the upward direction (arrow direction) together with the second case member 224. Accordingly, the connection between the electrode tab 230 and the electrode lead 240 is cut off

Except for the structure in which the electrode tab and the electrode lead are cut off from the connection part, the remaining structures are the same as those of the embodiment of FIG. 1 , and thus a detailed description thereof will be omitted.

In the case where the power is disconnected in both directions as described above, the predictability of the disconnection is higher and the accuracy of the disconnection can be further increased compared to the case where the power is disconnected in one direction. This is because, when power is disconnected in one direction, the lead or tab may move along the direction, so that power disconnection may not be performed accurately, and in this case, it is difficult to effectively secure the safety of the battery.

Although described above with reference to the drawings according to the embodiment of the present invention, those skilled in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above content.

Claims (14)

an electrode assembly having a structure in which a separator is interposed between the positive electrode, the negative electrode, and the positive electrode and the negative electrode; and
a battery case in which a first electrode assembly accommodating part in which a part of the electrode assembly is embedded and a second electrode assembly accommodating part in which the remaining part of the electrode assembly is embedded;
contains,
The electrode tabs extending from the electrode plates of the electrode assembly are coupled to the other end portion of the electrode lead from which one end portion protrudes to the outside of the battery case,
so that at least one of the electrode tabs and the electrode lead, or the connection portion between the electrode tabs and the electrode lead, may be cut off due to the expansion deformation of the battery case when the internal pressure of the battery cell rises,
(i) one surface of the electrode tabs facing the electrode lead and/or (ii) one surface of the electrode lead facing the electrode tabs is fused to the inner surface of the battery case,
The bonding strength of the electrode tabs and the electrode lead in the connection part is,
Relatively smaller than the fusion strength between the electrode tabs and the battery case or the fusion strength between the electrode lead and the battery case,
The bonding strength of the electrode tabs and the electrode lead in the connection part is,
50% to 99% of the fusion strength between the electrode tabs and the battery case or between the electrode lead and the battery case,
The electrode tabs and the electrode lead are coupled by ultrasonic welding,
At least one of the electrode tabs and the electrode lead has a pitch pattern formed on one surface to which ultrasonic welding is applied,
The positive tabs and the negative tabs are formed in opposite directions to each other,
The battery case is composed of a laminate sheet including a resin outer layer, a barrier metal layer, and a heat meltable resin sealant layer,
Polyethylene terephthalate (PET) and stretched nylon film are used for the polymer resin of the resin outer layer of the battery case ,
The rupture strength of the electrode tabs is relatively smaller than the fusion strength between the electrode tabs and the battery case, or the fusion strength between the electrode lead and the battery case,
A battery cell used in an electric vehicle or hybrid electric vehicle in which a part of the electrode tab ruptures earlier than between the electrode tabs and the battery case or between the electrode lead and the battery case when the battery case is expanded and deformed. The electric vehicle or hybrid according to claim 1, wherein the connection part between the electrode tab and the electrode lead is located on an unsealed part between the electrode assembly accommodating part and the sealing part formed on the outer periphery of the electrode assembly accommodating part. used in electric vehicles battery cell. The method of claim 1,
the battery case includes a first case member and a second case member;
the first electrode assembly accommodating part is formed on a first case member, and the second electrode assembly accommodating part is formed on a second case member;
a surface of one electrode tab facing the electrode lead is fused to an inner surface of the first case member;
A battery cell used in an electric vehicle or hybrid electric vehicle, characterized in that one surface of the electrode lead facing the electrode tabs is fused to the inner surface of the second case member. delete delete delete The electric vehicle or hybrid electric vehicle according to claim 1, wherein the rupture strength of the electrode lead is relatively smaller than the fusion strength between the electrode tabs and the battery case or the fusion strength between the electrode lead and the battery case. battery cell. delete delete The battery cell according to claim 1, wherein a heat-sealable film is interposed between the electrode tabs and the battery case or between the electrode lead and the battery case. The battery cell according to claim 10, wherein the heat-sealable film is a polypropylene film. delete delete delete

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