KR20130116805A - Electrode comprising compound having cyano group and lithium secondary battery comprising the same - Google Patents

Abstract

PURPOSE: An electrode is provided to be able to show an excellent adhesive force even with a small amount by including a cyan-containing compound as a binder. CONSTITUTION: An electrode includes an electrode active material for a secondary battery in which an electrode formulation layer formed on an electrode current collector, and the electrode formulation layer occluding and separating lithium ions, a conductive material and a binder. The binder includes a compound containing cyan (-CN). The content of the compound containing cyan is 2-6 weight% to the total weight of the electrode formulation. A lithium secondary battery comprises said electrode and a polymer membrane. In the lithium secondary battery, an electrode assembly with a structure that a polymer membrane is interposed between the cathode and the anode is built in a battery case.

Description

Electrode comprising a compound containing a cyan group and a lithium secondary battery comprising the same {Electrode Comprising Compound Having Cyano group and Lithium Secondary Battery Comprising The Same}

The present invention relates to a secondary battery capable of repeated charging and discharging and an electrode constituting the secondary battery.

The increase in the price of energy sources due to the depletion of fossil fuels, the increase of interest in environmental pollution, and the demand for environmentally friendly alternative energy sources are becoming indispensable factors for future life. Various researches on power generation technologies such as nuclear power, solar power, wind power, and tidal power have been continuing, and electric power storage devices for more efficient use of such generated energy have also been attracting much attention.

Particularly, in the case of a lithium secondary battery, the demand for an energy source is rapidly increasing due to an increase in technology development and demand for a mobile device. Recently, the use of a lithium secondary battery as a power source for an electric vehicle (EV) and a hybrid electric vehicle , And the area of use is also expanding for applications such as power assisted power supply through gridization.

The binder plays an important role in mechanically stabilizing the electrode.

The electrode expands and contracts repeatedly according to charging and discharging of the battery. When such deformation occurs, the bonding between the active material or the conductive material is loosened and the contact resistance between particles increases. As a result, ohmic resistance of an electrode rises and battery characteristic falls.

These problems are caused by a decrease in the mechanical stability of the electrode can be solved by the use of a binder.

However, the use of excess binder not only reduces the electrode active material ratio, but also causes the binder itself to act as a resistance element in the electrode, thereby reducing the performance of the battery.

On the other hand, insufficient adhesive force causes an electrode peeling phenomenon in a process such as electrode drying and pressing to increase the electrode failure rate. In addition, peeling of the electrode may occur due to an external impact, which may adversely affect the stability of the battery, such as life characteristics.

Therefore, there is a need for an electrode design capable of realizing effective adhesion and performance by differentiating types of binders according to characteristics of electrode active materials.

The present invention is to provide an electrode comprising a compound containing a cyan group (-CN) as a binder within a predetermined content range and a lithium secondary battery comprising the same.

According to the present invention,

An electrode mixture layer comprising an electrode active material for a secondary battery, a conductive material, and a binder that occludes and desorbs lithium ions is formed on the electrode current collector, and the binder contains a compound containing a cyan group (-CN). An electrode is provided.

The present invention also provides a lithium secondary battery having a structure in which an electrode assembly having a structure in which a polymer film is interposed between a cathode, an anode, and a cathode and an anode is housed in a battery case and sealed. The lithium secondary battery may include a lithium salt-containing non-aqueous electrolyte.

The lithium secondary battery may be a lithium ion battery, may be a lithium ion polymer battery, may be a lithium polymer battery.

The electrode may be an anode or a cathode, and may be manufactured by a manufacturing method including the following processes.

The electrode manufacturing method,

Preparing a binder solution by dispersing or dissolving the binder in a solvent;

Preparing an electrode slurry by mixing the binder solution with an electrode active material and a conductive material;

Coating the electrode slurry on a current collector;

Drying the electrode; And

Compressing the electrode to a constant thickness.

In some cases, the method may further include drying the rolled electrode.

The binder solution manufacturing process is a process of preparing a binder solution by dispersing or dissolving a binder in a solvent.

The binder may contain a compound containing a cyan group.

The compound containing the cyan group is cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoacrylate, cyanoethylsucrose , Polyacrylonitrile, poly (acrylonitrile-co-methylmethacrylate), poly (acrylonitrile-co-methacrylic acid), poly (acrylonitrile-co-methylacrylonitrile, poly (acrylonitrile) Krill-co-lithium methacrylate), etc., but is not limited thereto.

The compound containing the cyan group may be an acrylonitrile-based compound, specifically, may be poly acrylonitrile.

The content of the compound including the cyan group may be 2% by weight to 6% by weight or less based on the total weight of the electrode mixture.

When the content of the compound containing the cyan group is less than 2% by weight, it has an adhesive force of less than 8 N / m, so that the ohmic resistance of the electrode is increased, thereby deteriorating battery characteristics. Compounds containing groups themselves are undesirable because they act as resistance.

Within the above range, it may have an adhesive force in the range of 8.0 N / m or more to less than 130 N / m.

The binder may further include all binders known in the art, and specifically, fluorine resin, polyolefin, styrene-butadiene rubber, carboxy methyl cellulose, mussel protein (dopamine), silane, ethyl cellulose , Methyl cellulose, hydroxypropyl cellulose, polyethylene glycol, polyvinyl alcohol, may be selected from the group consisting of an acrylic copolymer.

The solvent may be selectively used according to the type of the binder. For example, an organic solvent such as isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, and the like may be used.

As one specific embodiment of the present invention, PVdF may be dispersed / dissolved in NMP (N-methyl pyrrolidone) to prepare a binder solution for the positive electrode, and SBR (Styrene-Butadiene Rubber) / CMC (Carboxy Methyl Cellulose) may be used. It is also possible to prepare a binder solution for the negative electrode by dispersing / dissolving in.

An electrode slurry may be prepared by mixing / dispersing an electrode active material and a conductive material in the binder solution. The electrode slurry thus prepared may be transferred to a storage tank and stored until the coating process. In the said storage tank, in order to prevent an electrode slurry from hardening, an electrode slurry can be stirred continuously.

The electrode 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 + y} Mn _2-y O ₄ (where y 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 ; Formula _{LiNi 1-y M y O 2} ( where, the M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, y = 0.01 ~ 0.3 Im) Ni site type lithium nickel oxide which is represented by; Formula LiMn _2-y M _y O ₂ , wherein M = Co, Ni, Fe, Cr, Zn or Ta and y = 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; Carbon such as Fe ₂ (MoO ₄ ) ₃ , non-graphitizable 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, Bi ₂ O ₅ and the like; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like, but are not limited to these.

In a non-limiting example of the present invention, the electrode active material may include lithium metal oxide, and the lithium metal oxide may be preferably represented by the following formula (1).

Li _a M ' _b O _4-c A _c (1)

In the above formula, M 'is at least one element selected from the group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al and Zr;

a and b are 0.1? a? 4; Is determined according to the oxidation number of M 'in the range of 0.2? B? 4;

c is determined according to the oxidation number in the range of 0? c <0.2;

A is one or more of an anion of -1 or -2.

The oxide of Formula (1) may be represented by the following Formula (2).

Li _a Ti _b O ₄ (2)

In the above formula, 0.5? A? 3, 1? B? 2.5.

The lithium metal oxide may be Li _0.8 Ti _2.2 O ₄ , Li _2.67 Ti _1.33 O ₄ , LiTi ₂ O ₄ , Li _1.33 Ti _1.67 O ₄ , Li _1.14 Ti _1.71 O _4, or the like. However, it is not limited only to these.

In a non-limiting embodiment of the present invention, the lithium metal oxide may be Li _1.33 Ti _1.67 O ₄ or LiTi ₂ O ₄ . Li _1.33 Ti _1.67 O ₄ has a spinel structure with little change in crystal structure during charge and discharge and excellent reversibility.

The lithium metal oxide can be produced by a production method known in the art, for example, can be produced by a solid phase method, hydrothermal method, sol-gel method and the like. A detailed description thereof will be omitted.

The lithium metal oxide may be in the form of secondary particles in which primary particles are aggregated.

The particle diameter of the secondary particles may be 200 nm to 30 ㎛.

If the particle diameter of the secondary particles is less than 200 nm, it is not preferable because a high ratio of binder content is required in order to attach the electrode to the current collector due to the extremely large surface area, and it is also undesirable because side reactions with the electrolyte solution may be promoted.

In addition, in a non-limiting embodiment of the present invention, the electrode active material may include a lithium metal oxide having a spinel structure represented by the following formula (3).

Li _x M _y Mn _2-y O _4-z A _z (3)

Wherein 0 < y < 2, 0 z < 0.2,

M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, ;

A is one or more of an anion of -1 or -2.

The maximum substitution amount of A may be less than 0.2 mol%, and in a specific embodiment of the present invention, A may be at least one anion selected from the group consisting of halogen, S and N, such as F, Cl, Br, and I.

By substituting these anions, the binding force with the transition metal is improved and the structural transition of the compound is prevented, so that the lifetime of the battery can be improved. On the other hand, if the amount of substitution of the anion A is too large (t ≧ 0.2), it is not preferable because the life characteristics are lowered due to the incomplete crystal structure.

Specifically, the oxide of Formula (3) may be a lithium metal oxide represented by the following Formula (4).

Li _x Ni _y Mn _2-y O ₄ (4)

In the above formula, 0.9? X? 1.2 and 0.4? Y? 0.5.

More specifically, the lithium metal oxide may be LiNi _0.5 Mn _1.5 O ₄ or LiNi _0.4 Mn _1.6 O ₄ .

The conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery. Examples of the conductive material include graphite such as natural graphite and 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 whiskeys 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.

Filler, etc. may be selectively added to the electrode slurry as necessary.

The filler is not particularly limited as long as it is a fibrous material without causing chemical change in the battery. Examples of the filler include olefinic polymers such as polyethylene and polypropylene; Fibrous materials, such as glass fiber and carbon fiber, etc. can be used.

The process of coating the electrode slurry on the current collector is a process of coating the electrode slurry on the current collector in a predetermined pattern and a constant thickness by passing through a coater head.

The method of coating the electrode slurry on the current collector, the method of distributing the electrode slurry on the current collector and then uniformly dispersed using a doctor blade, die casting, comma coating coating, screen printing, and the like. In addition, the electrode slurry may be bonded to the current collector by pressing or lamination after molding on a separate substrate.

The current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver, and the like, aluminum-cadmium alloy, and the like can be used. The positive electrode current collector may be formed into various shapes such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric, or the like by forming fine irregularities on the surface to enhance the bonding force of the positive electrode active material. Specifically, the positive electrode current collector may be a metal current collector including aluminum, and the negative electrode current collector may be a metal current collector including copper. The electrode current collector may be a metal foil, and may be an aluminum (Al) foil or a copper (Cu) foil.

The drying process is a process of removing the solvent and water in the slurry to dry the slurry coated on the metal current collector, in a specific embodiment, is dried within 1 day in a vacuum oven of 50 to 200 ℃.

After the drying process, a cooling process may be further included, and the cooling process may be slow cooling to room temperature so that the recrystallized structure of the binder is well formed.

In order to increase the capacity density of the electrode after the coating process and to increase the adhesion between the current collector and the active materials, the electrode may be compressed into a desired thickness by passing it between two hot-rolled rolls. This process is called a rolling process.

Before passing the electrode between two hot heated rolls, the electrode can be preheated. The preheating process is a process of preheating the electrode before it is introduced into the roll in order to increase the compression effect of the electrode.

The electrode after the rolling process is completed as described above, may be dried within a day in a vacuum oven at 50 to 200 ℃ as a range satisfying the temperature of the melting point or more of the binder. The rolled electrode may be cut to a constant length and then dried.

After the drying process, a cooling process may be further included, and the cooling process may be slow cooling to room temperature so that the recrystallized structure of the binder is well formed.

The polymer membrane is a separator that separates between the positive electrode and the negative electrode. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as the separator.

As the separator, 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; Kraft paper and the like are used. Representative examples currently on the market include the Celgard ^R 2400, 2300 (from Hoechest Celanese Corp.), polypropylene separator (from Ube Industries Ltd. or Pall RAI), and polyethylene series (from Tonen or Entek).

In some cases, a gel polymer electrolyte may be coated on the separation membrane to increase the stability of the cell. Representative examples of such a gel polymer include polyethylene oxide, polyvinylidene fluoride, and polyacrylonitrile.

The electrode assembly may include a jelly-roll electrode assembly (or wound electrode assembly), a stacked electrode assembly (or a stacked electrode assembly), or a stack & folding electrode assembly having a structure known in the art.

In the present specification, the stack & folding type electrode assembly is a method of folding or winding a separator sheet after arranging unit cells having a structure in which a separator is interposed between an anode and a cathode on a separator sheet. It can be understood as a concept including a stack & folding type electrode assembly to be manufactured.

In addition, the electrode assembly may include an electrode assembly having a structure in which any one of an anode and a cathode is laminated by a method such as thermal fusion in a state in which a structure is interposed between the separators.

As the non-aqueous electrolyte, a non-aqueous electrolyte, an organic solid electrolyte, an inorganic solid electrolyte, and the like are used.

Examples of the nonaqueous electrolyte include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate , Gamma -butyrolactone, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, Diethyl ether, formamide, dimethyl formamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, trimethoxymethane, dioxolane A non-protonic organic solvent such as an ether, a methyl pyrophosphate, or an ethyl propionate is used as the solvent, a sulfone, a methyl sulfolane, a 1,3-dimethyl-2-imidazolidinone, a propylene carbonate derivative, a tetrahydrofuran derivative, .

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, sulfates, and the like 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 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, LiSCN, LiC (CF 3 SO 2) 3, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, 4-phenylborate, imide, and the like can be used.

For the purpose of improving the charge / discharge characteristics and the flame retardancy, the electrolytic solution is preferably mixed with an organic solvent such as pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, Benzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, . 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), FPC (fluoro-propylene carbonate), and the like.

The lithium secondary battery according to the present invention can exhibit a 90% or more discharge capacity retention rate during 3C discharge.

The lithium secondary battery according to the present invention can be used not only in a battery cell used as a power source of a small device but also as a unit cell in a middle- or large-sized battery module including a plurality of battery cells.

Also, the present invention provides a battery pack including the battery module as a power source of a middle- or large-sized device, wherein the middle- or large-sized device is an electric vehicle (EV), a hybrid electric vehicle (HEV) An electric vehicle including a plug-in hybrid electric vehicle (PHEV), a power storage device, and the like, but the present invention is not limited thereto.

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

Since the electrode according to the present invention contains a compound containing a cyan group as a binder, there is an advantage that can exhibit excellent adhesion even in a small amount.

In addition, since it is contained in more than 2% by weight to 6% by weight relative to the total weight of the electrode mixture, it can exhibit an adhesive force of 8 N / m or more even with a small content that does not act as a resistance element.

Therefore, the binder including the cyan group-containing compound according to the present invention, it is preferable to use the oxide of the formula (1) to 4 as the electrode active material that does not have the volume expansion and excellent electrical conductivity due to repeated charging and discharging Can be.

1 is a graph comparing output characteristics of non-limiting embodiments of the invention.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

&Lt; Example 1 >

Li (Ni _0.5 Mn _1.5 ) O ₄ (BASF Co., Ltd.): Super P (Timcal Co., Ltd.): A positive electrode slurry was prepared by mixing a solid content having a mass ratio of 90: 5: 5 of PVdF (Solef Co., Ltd. 6020) in an NMP solvent. A positive electrode having a loading amount of 1 mAh / cm ² was prepared by applying to 20 μm thick aluminum foil.

Li ₄ Ti ₅ O ₁₂ (Posco ESM T30): A solid component having a weight ratio of 90: 6: 4 of Super-P (Timcal): polyacrylonitrile (PAN) was added to an NMP solvent to prepare an anode slurry And applied to an aluminum foil having a thickness of 20 탆 to prepare a negative electrode having a loading amount of 1 mAh / cm ² .

As a separator, a battery cell was prepared using an electrolyte solution in which 1 M LiPF ₆ salt was added to a polyethylene membrane (Celgard, 20 μm thick) and a solvent having EC: DMC: EMC = 1: 1: 1.

<Example 2>

A battery cell was prepared in the same manner as in Example 1, except that the mass ratio of Li ₄ Ti ₅ O ₁₂ : Super-P: polyacrylonitrile (PAN) was 90: 7: 3.

&Lt; Comparative Example 1 &

A battery cell was prepared in the same manner as in Example 1, except that the mass ratio of Li ₄ Ti ₅ O ₁₂ : Super-P: polyacrylonitrile (PAN) was 90: 3: 7.

Comparative Example 2

A solid slurry having a mass ratio of Li ₄ Ti ₅ O ₁₂ : Super-P: PVdF (Solef 6020) of 87: 5: 8 was added to an NMP solvent to prepare a negative electrode slurry, and applied to an aluminum foil having a thickness of 20 μm. A negative electrode having 1 mAh / cm ² was produced.

<Experimental Example 1>

Adhesion tests were performed using the electrodes of Examples 1, 2 and Comparative Examples 1,2. After cutting the surface of the electrode of Example 1, 2 and the comparative example 1, 2, and fixing to the slide glass, peeling strength of 180 degree was measured, peeling off an electrical power collector. Evaluation was made into the average value by measuring five or more peeling strengths.

Adhesive force (N / m) Example 1 21.4 Example 2 8.4 Comparative Example 1 130.2 Comparative Example 2 11.4

Referring to Table 1, Example 1 exhibits 21.4 N / m of adhesion even though it contains 4% by weight of polyacrylonitrile, and Example 2 contains 8.4% of 3% by weight of polyacrylonitrile. Compared with the adhesive force of N / m, it can be seen that Comparative Example 2 exhibits an adhesive force of 11.4 N / m even though it contains 8% by weight of PVdF. Examining Comparative Examples 1 and 2 together, it can be seen that Comparative Example 1 exhibits significantly greater adhesive strength than Comparative Example 2, despite the difference of 1% by weight.

<Experimental Example 2>

The battery cells of Examples 1, 2 and Comparative Example 1 were charged at 0.1 C in a voltage range of 3.4 to 4.85 V and discharged at 0.1 C, 1.0 C, and 3.0 C, respectively, to measure output characteristics. The results are shown in Fig. Referring to FIG. 1, it can be seen that in Comparative Example 1, the discharge capacity retention rate gradually decreased at a high rate compared to Examples 1 and 2. FIG.

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 (17)

An electrode mixture layer comprising an electrode active material for a secondary battery, a conductive material, and a binder that occludes and desorbs lithium ions is formed on the electrode current collector, and the binder contains a compound containing a cyan group (-CN). An electrode. The method of claim 1,
The compound containing the cyan group is cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoacrylate, cyanoacrylate, cyanoethylsucrose, polyacrylonitrile, Poly (acrylonitrile-co-methylmethacrylate), poly (acrylonitrile-co-methacrylic acid), poly (acrylonitrile-co-methylacrylonitrile, poly (acrylonitrile-co-methacrylic) And one or more electrodes selected from the group consisting of lithium acid). The electrode according to claim 2, wherein the compound containing cyan group is an acrylonitrile compound. The electrode according to claim 3, wherein the acrylonitrile-based compound is polyacrylonitrile. The electrode according to claim 1, wherein the content of the compound including the cyan group is 2 wt% to 6 wt% based on the total weight of the electrode mixture. The electrode according to claim 1, wherein the electrode active material contains a lithium metal oxide having a spinel structure represented by the following general formula (1):
Li _x M _y Mn _{2 - y} O _{4 - z z} (1)
Wherein 0 < y < 2, 0 z < 0.2,
M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, ;
A is one or more of an anion of -1 or -2. The electrode according to claim 6, wherein the oxide of formula (1) is represented by the following formula (2):
Li _x Ni _y Mn _2-y O ₄ (2)
Wherein 0.9 ≦ x ≦ 1.2 and 0.4 ≦ y ≦ 0.5. 8. The electrode of claim 7, wherein the lithium metal oxide is LiNi _0.5 Mn _1.5 O ₄ or LiNi _0.4 Mn _1.6 O ₄ . The electrode according to claim 1, wherein the electrode active material comprises a lithium metal oxide represented by the following general formula (3):
Li _a M ' _b O _{4-ca c} (3)
In the above formula, M 'is at least one element selected from the group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al and Zr;
a and b are 0.1? a? 4; Is determined according to the oxidation number of M 'in the range of 0.2? B? 4;
c is determined according to the oxidation number in the range of 0? c <0.2;
A is one or more of an anion of -1 or -2. The electrode according to claim 9, wherein the oxide of Formula 3 is represented by the following Formula (4):
Li _a Ti _b O ₄ (4)
In the above formula, 0.5? A? 3, 1? B? 2.5. The electrode of claim 10, wherein the lithium metal oxide is Li _1.33 Ti _1.67 O ₄ or LiTi ₂ O ₄ . A lithium secondary battery comprising the electrode according to any one of claims 1 to 11 and a polymer membrane, and an electrode assembly having a structure in which a polymer membrane is interposed between a cathode and an anode. The lithium secondary battery of claim 12, wherein the lithium secondary battery is a lithium ion battery. The lithium secondary battery of claim 12, wherein the lithium secondary battery is a lithium ion polymer battery. The lithium secondary battery of claim 12, wherein the lithium secondary battery is a lithium polymer battery. The lithium secondary battery according to claim 12, wherein the lithium secondary battery has a discharge capacity retention rate of 90% or more during 3 C discharge. 6. The electrode according to claim 5, having an adhesive force in the range of 8.0 N / m or more to less than 130 N / m.

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