KR20180116810A - Electrode Assembly Improved Thermal Safety by Binder Coating Layer - Google Patents

Abstract

The present invention provides a laminated electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode,
A positive electrode tab and a negative electrode tab protruding from one side of the outer circumferential surface of the positive electrode and the negative electrode in the same direction,
The separation membrane is formed to have a size larger than that of the anode and the cathode so as to have an extending portion on the entire outer peripheral surface,
Wherein a portion of the positive electrode tab and a portion of the negative electrode tab which are in contact with the separator is coupled by a binder coating layer on an outer surface of the positive electrode tab and the negative electrode tab protruding in the same direction, And an electrode assembly in which an end portion of the anode and / or the cathode and a portion in contact with the separation membrane are coupled by a binder coating layer.

Description

[0001] The present invention relates to an electrode assembly having improved thermal stability by a binder coating layer,

The present invention relates to an electrode assembly in which thermal stability is improved by a binder coating layer.

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.

As a development base for such a ubiquitous society, a lithium secondary battery occupies an important position. Specifically, the rechargeable lithium secondary battery is widely used as an energy source for wireless mobile devices, and is proposed as a solution for air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels And also as an energy source for electric vehicles, hybrid electric vehicles, and the like.

As described above, as the devices to which the lithium secondary battery is applied are diversified, the lithium secondary battery has been diversified to provide an appropriate output and capacity for the applied device. In addition, miniaturization is strongly demanded.

Typically, in terms of the shape of the battery, there is a high demand for a prismatic secondary battery and a pouch type secondary battery which can be applied to products such as mobile phones with a thin thickness, and the advantages of high energy density, discharge voltage,

There is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries.

The secondary battery includes a cylindrical battery and a prismatic battery in which the electrode assembly is housed in a cylindrical or rectangular metal can according to the shape of the battery case, and a pouch type battery in which the electrode assembly is housed in a pouch-shaped case of an aluminum laminate sheet .

Further, the secondary battery is classified according to the structure of the electrode assembly having the structure in which the separator interposed between the anode, the cathode, and the anode and the cathode is laminated. Typically, the long battery- A stacked (stacked) electrode assembly in which a plurality of positive electrodes and negative electrodes cut in a predetermined size unit are sequentially stacked with a separator interposed therebetween, the jelly-roll type (wound type) electrode assembly having a structure in which a separator is interposed; In recent years, in order to solve the problems of the jelly-roll type electrode assembly and the stack type electrode assembly, an electrode assembly having an advanced structure, which is a combination of the jelly-roll type and the stack type, Bi-cells or full cells, which are laminated with an anode and a cathode interposed therebetween, are sequentially wound on a separator film The stacking / folding type electrode assembly of a structure has been developed.

In recent years, a pouch-shaped battery having a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-shaped battery case of an aluminum laminate sheet has attracted a great deal of attention due to low manufacturing cost, small weight, And its usage is gradually increasing.

One of the major research tasks in such secondary batteries is to improve safety. For example, a secondary battery can have a high temperature and / or high temperature inside the battery that can be caused by an abnormal operating condition of the battery, such as an internal short circuit, an overcharged condition exceeding an allowable current and voltage, exposure to a high temperature, The explosion of the battery may be caused by high pressure.

One of the problems of safety is that the internal short circuit due to shrinkage or breakage of the separator which occurs when the battery is exposed to a high temperature is very serious.

In general, a porous polymer film such as polyethylene or polypropylene is used as a separator. Such a separator is cheap and has excellent chemical resistance and is advantageous for operation of a battery. However, it is likely to shrink in a high temperature environment.

FIG. 1 schematically shows the shape of the separation membrane contraction of a typical stacked-type electrode assembly of the related art.

Referring to FIG. 1, the electrode assembly 10 has a structure in which a cathode and an anode are alternately disposed and a separation membrane 13 is interposed between the anodes and the cathode. The positive electrode tab 11 and the negative electrode tab 11 are formed from the positive electrode and the negative electrode, The negative electrode tab 12 protrudes.

When the electrode assembly is exposed to a high temperature, the separation membrane 13 is contracted toward the inner side of the electrode assembly 10 on the surface on which the positive electrode tab 11 and the negative electrode tab 12 are protruded, .

When the size of the separator is designed to be much larger than that of the positive electrode and the negative electrode in consideration of the degree of shrinkage of the separator in order to prevent the above problem, due to the extended portion of the separator protruding outside the periphery of the positive electrode and the negative electrode, Not only can the insertion performance of the electrode assembly with respect to the battery case be reduced, but also the volume-to-volume capacity can be reduced by the space occupied by the separator.

Therefore, there is a high need for a technique capable of fundamentally solving such problems.

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.

More specifically, it is an object of the present invention to provide a method of manufacturing a semiconductor device, in which a binder coating layer is formed on a portion where a separator and an electrode tab are in contact with each other and a portion where an electrode end and a separator are in contact with each other, To provide an electrode assembly.

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

An electrode assembly having a laminated structure including an anode, a cathode, and a separator interposed between the anode and the cathode,

A positive electrode tab and a negative electrode tab protruding from one side of the outer circumferential surface of the positive electrode and the negative electrode in the same direction,

The separation membrane is formed to have a size larger than that of the anode and the cathode so as to have an extending portion on the entire outer peripheral surface,

Wherein a portion of the positive electrode tab and a portion of the negative electrode tab which are in contact with the separator is coupled by a binder coating layer on an outer surface of the positive electrode tab and the negative electrode tab protruding in the same direction, And a portion where the end of the anode and / or the cathode contacts with the separator on the opposite surface is bonded by the binder coating layer.

Here, the ends of the positive electrode and the negative electrode start from the end and are substantially inward to 5% of the total length of the electrode.

As described above, in the electrode assembly according to the present invention, the portion where the separator and the electrode tab are in contact with each other and the portion where the separator and the electrode end are in contact with each other are coupled by the binder coating layer, thereby preventing the separator from shrinking into the electrode assembly As a result, there is an effect that heat safety can be improved by preventing a short circuit between the anode and the cathode.

In this regard, conventionally, processes such as joining the extended portions of the separator as a whole, or joining a part thereof have been performed.

However, the shrinkage degree of the separator is large on the portion where the electrode tab is formed and on the opposed surface thereof, as described in the background art, and the shrinkage degree of the separator increases toward both ends of the outer surface,

Therefore, it is not necessary to bond all extension portions of the separation membrane in order to prevent such shrinkage. In this case, an unnecessary loss is caused in terms of the tape and the heat application necessary for bonding, and when bonding is carried out in connection with electrolyte impregnation, electrolyte impregnability becomes poor. In the case where only a part thereof is bonded, if the range is very small, sufficient separation force of the separation membrane in the shrinking direction of the separation membrane can not be exhibited, and a desired degree of thermal stability can not be obtained.

In this way, even when the separator and the electrode assembly are combined with each other, the position is extremely important, and the content of the coating layer for bonding and the bonding method all influence.

Accordingly, the inventors of the present application have found that while employing a configuration in which a separator and an electrode are bonded to each other on the surface of the electrode taps in the shrinking direction of the separator and the surface opposite to the separator, the binder coating layer It was confirmed that the desired effect can be exhibited without loss of volume.

FIG. 2 is a schematic view of an electrode assembly for clearly showing a portion where the binder coating layer of the present invention is formed.

Referring to FIG. 2, the electrode assembly 100 has a structure in which a cathode and an anode are alternately disposed and a separation membrane 130 having a larger size is interposed between the anodes and the cathode, (110) and a negative electrode tab (120) are protruded.

A binder coating layer 141 is interposed between the positive electrode tab 110 and the negative electrode tab 120 and the negative electrode tab 120 and the separator 130 are in contact with each other, A binder coating layer 142 is interposed between the separating film 130 and the binder coating layer 142. The binder coating layer 143 is interposed between the end of the anode or the cathode and the separating film 130, have.

The positive electrode tab and the negative electrode tab are formed on both sides of the electrode so that the active material layer is not formed and the binding force with the separator is weak. The heat shrinkage of the separator can be sufficiently prevented even if the binder coating layer is formed only on the contact portion.

Therefore, the content of the binder coating layer can be minimized and sufficient heat shrinkage can be prevented.

In order to bond the separator and the electrode component according to the present invention, it is most preferable that the separator and the electrode component are made of a material that does not react with the internal materials of the battery and can exert a predetermined adhesive force even when the electrolyte is impregnated. And the binder coating layer was formed using a binder used as the binder coating layer, and in detail, the binder coating layer was made of polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, (EPDM), sulfonated EPDM, styrene-butadiene rubber, and fluorine rubber, or one or more members selected from the group consisting of ethylene-propylene-diene terpolymer It can be made of two or more combinations.

Therefore, the desired effect of the present invention can be exhibited without side reactions with other materials in the electrode assembly.

On the other hand, the length of the extended portion of the separator for coupling with the components of the electrode may be 2% to 10% of the length of the positive electrode and the negative electrode, on the outer surface and the opposite surface where the positive electrode tab and the negative electrode tab protrude.

If the elongation percentage of the separator is less than 2%, heat shrinkage can not be prevented to a desired degree. If it exceeds 10%, the electrolytic solution impregnability is hindered and the length of the positive electrode tab and the negative electrode tab must be long, It is not preferable from the viewpoint of efficiency.

Here, the length means a size in a direction parallel to the protruding direction of the positive electrode tab and the negative electrode tab.

In addition, the width extending from both sides of the separator in the vertical direction to the outer surface where the positive electrode tab and the negative electrode tab protrude may be 5% to 50% of the width of the positive electrode and the negative electrode.

When the width is less than 5% of the width of the positive electrode and the negative electrode, the width slightly shrinks in the width direction due to heat, which may cause short-circuiting of the electrode. When the width exceeds 50%, the separator becomes too large, It is not preferable since the efficiency of the contrast capacity may be deteriorated.

Here, the width means a size in a direction perpendicular to the protruding direction of the positive electrode tab and the negative electrode tab.

The thickness of the binder coating layer may be 20% to 100% with respect to the thickness of the positive electrode tab or the negative electrode tab. If it is less than 20%, the desired heat shrinkage of the separator can not be prevented. If it exceeds 100%, it becomes too thick and the volume becomes larger due to the binder coating layer. It is not preferable because the bonding force at other portions may be deteriorated by the space.

In the electrode assembly according to the present invention that satisfies the above conditions, the extended portion of the separator on the outer surface of the positive electrode tab and the negative electrode tab protruding from the opposing surface can be contracted to 100% or less of the total extended length by heating , In particular to less than 90%.

Therefore, it is possible to prevent a short circuit between the positive electrode and the negative electrode, which is caused by the contraction of the extended portion of the separation membrane to the inside of the electrode assembly.

At this time, the heating may be 200 DEG C or less. If the temperature rises to a higher temperature beyond the above range, the shrinkage of the separator becomes worse or melts, and if it can be held up to the above range, it is possible to cover the use level of the battery.

The present invention also provides a battery cell including the electrode assembly, wherein the battery cell may be a lithium secondary battery, and the type thereof is not limited, and specific examples thereof include a high energy density, a discharge voltage, Lithium ion battery, lithium ion polymer battery and the like, which have advantages such as stability and stability.

The lithium secondary battery can be manufactured by incorporating the electrode assembly according to the present invention in a battery case and impregnating a lithium salt-containing non-aqueous electrolyte solution.

Hereinafter, other configurations of the electrode assembly and the lithium secondary battery of the present invention will be described.

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 not less than 3 micrometers and not more than 500 micrometers. Such a positive electrode collector is not particularly limited as long as it has conductivity without causing chemical change to the battery, and may be formed on the surface of stainless steel, aluminum, nickel, titanium, sintered carbon or aluminum or stainless steel 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; Li _x Mn _2-x O ₄ wherein x is 0 to 0.33, LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ Lithium manganese oxide; 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 anode current collector is generally made to have a thickness of not less than 3 micrometers and not more than 500 micrometers. The negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery. Examples of the negative electrode current collector include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver or the like, 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 &lt; 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 separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 300 mu m. 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 lithium salt-containing non-aqueous electrolyte solution is composed of a polar organic electrolyte and a lithium salt. As the electrolytic solution, a non-aqueous liquid electrolytic solution, an organic solid electrolyte, an inorganic solid electrolyte and the like are used.

Examples of the nonaqueous liquid electrolytic solution 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 non-aqueous liquid electrolyte may contain, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like are added It is possible. In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

As described above, the electrode assembly according to the present invention is characterized in that a binder coating layer is formed at a portion where the separator and the electrode tab are in contact with each other and at a portion where the electrode end and the separator are in contact with each other, Shrinkage is suppressed, internal short-circuiting is prevented, and safety can be improved.

In addition, since the binder coating layer is formed only at the portion where the most shrinkage can occur, the thermal shrinkage of the separator can be effectively prevented even with a small amount of the binder, so that the efficiency of the volume-to-volume capacity can be prevented from being lowered and deterioration of the electrolyte impregnability can be prevented .

1 is a schematic view showing heat shrinkage of a separation membrane of a conventional electrode assembly;
2 is a schematic diagram of an electrode assembly according to one embodiment of the present invention;
3 is a photograph showing the results according to Experimental Example 1. Fig.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the following examples.

&Lt; Comparative Example 1 &

(Negative electrode active material, graphite), a conductive material (Denka black) and a binder (PVdF) were mixed in NMP at a weight ratio of 92: 3: 5 and mixed to prepare a negative electrode material mixture. The negative electrode material mixture was coated Followed by rolling and drying to produce a negative electrode.

Denka black and a binder (PVdF) were mixed in NMP at a weight ratio of 88: 8.5: 3.5 by using LiNi _0.4 Mn _0.3 Co _0.3 O ₂ as a positive electrode active material, Coated on an aluminum foil, rolled and dried to prepare a positive electrode.

A polyethylene porous membrane (Asahi, thickness: 16 占 퐉) was placed as a separator on the surface of the outermost electrode assembly and between the cathode and the anode so as to have a size slightly larger than that of the anode and the cathode.

&Lt; Example 1 >

An electrode assembly was prepared in the same manner as in Comparative Example 1, except that a binder coating layer of PVdF was formed on the portion shown in Fig.

<Experimental Example 1>

Three electrode assemblies prepared in the same manner as in Comparative Example 1 and three electrode assemblies prepared in the same manner as in Example 1 were prepared and allowed to stand in a chamber at 130 ° C. for 5 minutes and then taken out to obtain a separator The degree of shrinkage was confirmed, and the results are shown in Fig.

3, the separation membrane of the electrode assembly having the binder coating layer according to the present invention hardly shrinks to such an extent that the surface electrode is not visible. However, the separation membrane of the electrode assembly without the binder coating layer is greatly shrunk, I can confirm almost everything. This means that the separator interposed between the anode and the cathode in the electrode assembly exhibits a similar pattern. In the case where the binder coating layer is formed as in the present invention, shorting between the anode and the cathode can be effectively prevented.

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 (10)

An electrode assembly having a laminated structure including an anode, a cathode, and a separator interposed between the anode and the cathode,
A positive electrode tab and a negative electrode tab protruding from one side of the outer circumferential surface of the positive electrode and the negative electrode in the same direction,
The separation membrane is formed to have a size larger than that of the anode and the cathode so as to have an extending portion on the entire outer peripheral surface,
Wherein a portion of the positive electrode tab and a portion of the negative electrode tab which are in contact with the separator is coupled by a binder coating layer on an outer surface of the positive electrode tab and the negative electrode tab protruding in the same direction, Wherein a portion of the anode and / or the cathode which is in contact with the separation membrane is coupled by a binder coating layer on the opposite surface. The electrode assembly according to claim 1, wherein a length of the extended portion of the separator extending from an outer surface and an opposite surface of the anode tab and the anode tab protruded is 2% to 10% of the length of the anode and the cathode. 2. The electrode assembly according to claim 1, wherein a width of each of the extending portions of the separator extending from both sides perpendicular to the outer surface of the anode tab and the anode tab protruded is 5% to 50% of the width of the anode and the cathode. . The method of claim 1, wherein the binder coating layer is selected from the group consisting of polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, Characterized in that the electrode assembly is made of one or a combination of two or more selected from the group consisting of ethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, . The electrode assembly according to claim 1, wherein the thickness of the binder coating layer is 20% to 100% of the thickness of the positive electrode tab or the negative electrode tab. The electrode assembly according to claim 1, wherein an extension part of the separator on the outer surface of the positive electrode tab and the negative electrode tab protrudes and the opposite surface thereof is contracted to 100% or less of the total extension length by heating. The electrode assembly according to claim 6, wherein an extension part of the separator on the outer surface of the positive electrode tab and the negative electrode tab protrudes and the opposite surface thereof is contracted to 90% or less of the total extension length by heating. 8. The electrode assembly according to claim 6 or 7, wherein the heating is 200 DEG C or less. A battery cell comprising the electrode assembly according to claim 1. The battery cell according to claim 9, wherein the battery cell is a lithium secondary battery.

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