KR20140032624A - Electrode for secondary battery and method of preparing the same - Google Patents

Abstract

The present invention provides: an electrode for a secondary battery which includes (a) an electrode compound coating layer formed of an electrode compound including an electrode active material, a binder, and a conductive material, and (b) a carbon slurry coating layer formed of carbon slurry, and partially coated on an interface of the electrode compound coating layer and a current collector; and a method of manufacturing the same for remarkably improving adhesive force and output properties among the electrode compound and the current collector. [Reference numerals] (AA) HPPC resistance measurement; (BB) rapamycin (nM); (CC) Comparative example 1; (DD) Administration amount of radiation (Gy)

Description

Electrode for Secondary Battery and Manufacturing Method Thereof {Electrode for Secondary Battery and Method of Preparing the Same}

The present invention is a secondary battery electrode and its manufacturing method,

(a) an electrode mixture coating layer composed of an electrode mixture including an electrode active material, a binder, and a conductive material; And

(b) a carbon slurry coating layer composed of a carbon slurry and coated on at least a part of an interface between the electrode mixture coating layer and a current collector;

It relates to a secondary battery electrode and a manufacturing method thereof comprising a.

As the development and demand for mobile devices increases, the demand for secondary batteries as energy sources is increasing rapidly. Among them, many researches on lithium secondary batteries with high energy density and discharge voltage have been commercialized and widely used. have.

Generally, a lithium secondary battery comprises a separator disposed between an anode, a cathode, and both electrodes, and an electrolytic solution, and an electrolyte in which an appropriate amount of a lithium salt is dissolved in an organic solvent is used.

The electrode of such a lithium secondary battery is generally prepared by coating a current collector with a slurry for an electrode material mixture. The slurry for the electrode material mixture includes an electrode active material for intercalating and deintercalating lithium ions, a conductive material for imparting electrical conductivity , And a binder for bonding the electrode foil to the electrode foil in a solvent such as N-methyl pyrrolidone (NMP). However, in the production of such electrodes, the adhesion between the electrode material mixture and the current collector may be lowered during the pressing process or the subsequent manufacturing process, and dust may be generated. As a result of the volume change of the electrode caused by the progress of charging and discharging of the battery, The active material or the electrode active material may be desorbed between the electrode active material and the current collector so that the active material may not function properly.

Such deterioration of adhesive strength and detachment of the active material due to the deterioration of the active material increases the internal resistance of the battery, thereby deteriorating output characteristics and decreasing the battery capacity.

Therefore, in order to solve the above problems, various methods have been proposed, such as etching the surface of the current collector to form minute unevenness, or applying a specific material to the surface of the current collector to increase the bonding force with the current collector.

However, despite these attempts, the phenomenon of dust due to the decrease in adhesion between the electrode mixture and the current collector is not completely solved in the manufacturing process of the electrode, and due to the material applied to the surface of the current collector, There is a problem that the electrical conductivity of is reduced.

Therefore, there is a high demand for a technology capable of improving the bonding force without compromising the electrical conductivity between the current collector and the electrode mixture.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

After extensive research and various experiments, the inventors of the present application can achieve a desired effect when using an electrode for a secondary battery having a configuration including a carbon slurry coating layer and an electrode mixture coating layer continuously, as described later. It confirmed that there existed and came to complete this invention.

Therefore, the secondary battery electrode according to the present invention,

(a) an electrode mixture coating layer composed of an electrode mixture including an electrode active material, a binder, and a conductive material; And

(b) a carbon slurry coating layer composed of a carbon slurry and coated on at least a part of an interface between the electrode mixture coating layer and a current collector;

And a control unit.

That is, the electrode for secondary batteries according to the present invention is coated with a carbon slurry can improve the electrical conductivity between the current collector and the electrode mixture, the carbon slurry layer has an effect of widening the surface area, so the electrode for the current collector Has the advantage of increasing the adhesion of the mixture.

The carbon slurry may be, for example, at least one carbon-based material selected from the group consisting of graphite, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black, carbon fiber and carbon fluoride, And a polymeric material as a binder.

As the binder, the polymer material is a component that assists in bonding the carbon-based material to the current collector and the electrode mixture layer. For example, polyvinylidene fluoride (PvdF), polyvinyl alcohol, and carboxymethyl cellulose (CMC) , Starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butylene It may be one or two or more selected from the group consisting of rubber and fluorine rubber, but is not limited thereto. Specifically, it may be polyvinylidene fluoride (PvdF).

The carbon-based material may be included in 20 to 80% by weight based on the total weight of the carbon slurry. When the amount of the carbon-based material is too large, the amount of the binder may be relatively low, resulting in a problem of lowering the adhesive force. On the contrary, when the amount of the carbon-based material is too small, the desired electrical conductivity may not be obtained, which is not preferable. Specifically, the carbon-based material may be 30 to 70% by weight based on the total weight of the carbon slurry.

The carbon slurry coating layer may have a thickness of 0.5 to 50 ㎛. If the thickness of the carbon slurry coating layer is too thin, it is difficult to exert a desired electrical conductivity improvement effect, on the contrary, if too thick, the electrode mixture coating layer results in a decrease as compared to the specification, there is a problem because the battery capacity can be reduced. Therefore, the thickness of the carbon slurry coating layer may be specifically, 10 to 40 ㎛ thickness.

The carbon slurry coating layer may be coated on all or part of the surface of the current collector, and can be appropriately adjusted within a range capable of improving the bonding strength and electrical conductivity with the electrode mixture. The carbon slurry coating layer may be formed in 50 to 100% based on the surface area of the current collector in contact with the electrode mixture, specifically, may be formed in 80 to 100%.

The surface roughness of the carbon slurry coating layer may be appropriately adjusted according to the carbon slurry solid content ratio, and may be, for example, 0.01 to 30 μm, and specifically 0.1 to 10 μm. In the carbon slurry coating layer having such a surface roughness, the interface area with the electrode mixture coating layer is increased, and as a result, the adhesive force may be improved.

An interface between the carbon slurry coating layer and the electrode mixture coating layer may form an uneven interface structure.

The electrode mixture coating layer may have a thickness of 5 to 400 μm, specifically 20 to 200 μm. If the thickness of the coating layer is too small, it is difficult to expect the effect of the application, if the coating layer is too large it is not preferable because it inhibits the fusion of the current collector.

The density of the secondary battery electrode may be 1.5 to 5 g / cc. With such an electrode density, the contact area with the current collector can be kept large, so that an excellent conductive network can be formed, so that the electrical conductivity is excellent.

The electrode active material may be a positive electrode active material, or a negative electrode active material, or a positive electrode active material and a negative electrode active material, a specific configuration will be described below.

In addition, the method of manufacturing an electrode for a secondary battery according to the present invention,

(a) coating and drying a carbon slurry on a part or the entire surface of the current collector to form a carbon slurry coating layer;

(b) coating and drying an electrode mixture including an electrode active material, a binder, and a conductive material on the current collector on which the carbon slurry coating layer is formed to form an electrode mixture coating layer;

(c) roll pressing the continuously coated carbon slurry coating layer and the electrode mixture coating layer;

(d) applying the steps (a), (b) and (c) one or more times;

As shown in FIG.

In the step (a), as described above, the surface roughness of the carbon slurry coating layer may be controlled by controlling the solid content ratio of the carbon slurry.

In the step (b), by continuously coating the electrode mixture coating layer on the carbon slurry coating layer, the processability can be improved by reducing the manufacturing process cost, it is possible to increase the interface area of the carbon slurry coating layer and the electrode mixture coating layer.

The drying of steps (a) and (b) may be carried out within a temperature at which the binder in the carbon slurry and the electrode mixture slurry is not denatured, for example, the drying may be performed at 80 to 200 ° C. for 1 to 20 minutes. Can be done. More specifically, it may be performed at 100 to 150 ° C. for 1 to 10 minutes.

In the step (c), at the interface of the carbon slurry coating layer and the electrode mixture coating layer formed of the continuous coating through roll pressing, the electrode mixture may penetrate into the surface of the carbon slurry coating layer to improve contact with the carbon slurry coating layer. have. In this case, it is possible to control the penetration of the electrode mixture, specifically, the positive electrode active material, by controlling the solid secretion of the carbon slurry in the step (a).

According to the production method of the present invention by repeating the steps (a), (b) and (c) once or twice or more, a secondary comprising a carbon slurry coating layer and electrode mixture coating layer formed in two or more than three times A battery electrode can be provided.

The present invention also provides a secondary battery including the positive electrode, the negative electrode, or the positive electrode and the negative electrode as the secondary battery electrode, and the secondary battery may specifically be a lithium secondary battery.

Hereinafter, the configuration of such a lithium secondary battery will be described.

The lithium secondary battery includes a positive electrode prepared by applying a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode collector, followed by drying and pressing, and a negative electrode prepared using the same method. In this case, A filler is further added to the mixture.

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

The cathode active material may be, for example, a layered compound such as lithium cobalt oxide (LiCoO ₂ ) or lithium nickel oxide (LiNiO ₂ ) or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Lithium nickel manganese cobalt composite oxides such as LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , LiNi _0.5 Mn _0.3 Ni _0.2, and the like; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and LiNi _x Mn _{2 - x} O ₄ (0.01 ≦ x ≦ 0.6).

The conductive material is usually added in an amount of 1 to 50% 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 that 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 50 wt% 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, and various copolymers.

The filler is optionally used as a component for suppressing 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-based polymerizers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

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

The negative electrode active material may be, for example, graphite having a complete layered crystal structure such as natural graphite, soft carbon having a low crystalline graphene structure (structure in which hexagonal honeycomb planes of carbon are arranged in layers) and Carbon and graphite materials such as hard carbon, artificial graphite, expanded graphite, carbon fibers, non-graphitizable carbon, carbon black, carbon nanotubes, fullerenes, activated carbons, in which these structures are mixed with amorphous portions; _{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; Complexes of the above compounds can be used.

Such a lithium secondary battery may have a structure in which a lithium salt-containing electrolyte is impregnated in an electrode assembly having a separator interposed between a cathode and an anode.

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 electrolyte solution containing the lithium salt is composed of an electrolyte solution and a lithium salt. The electrolyte solution may be a non-aqueous organic solvent, an organic solid electrolyte, or an inorganic solid electrolyte, but is not limited thereto.

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

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, A polymer containing an ionic dissociation group and the like may 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 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide.

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), and the like.

In one example, lithium salts such as LiPF ₆ , LiClO ₄ , LiBF ₄ , LiN (SO ₂ CF ₃ ) _2, and the like, are linear with cyclic carbonates of EC or PC, which are highly dielectric solvents, and DEC, DMC, or EMC, which are low viscosity solvents. The lithium salt-containing non-aqueous electrolyte can be prepared by adding to a mixed solvent of carbonate.

Since the lithium secondary battery including the electrode according to the present invention has reduced internal resistance, the battery pack including the same may be used as a power source for a vehicle requiring high temperature stability, long cycle characteristics, high rate characteristics, and lifetime characteristics.

Examples of the vehicle may be an electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) But is not limited thereto.

As described above, since the secondary battery electrode according to the present invention is manufactured through a roll fleshing process after the carbon slurry coating layer and the electrode mixture coating layer are continuously formed on the current collector, the adhesion between the electrode mixture and the current collector is improved, and the resistance is increased. This can be reduced, the secondary battery comprising the same can exhibit excellent output characteristics.

1 is a graph showing the measurement of the HPPC resistance of a secondary battery comprising a positive electrode prepared according to Example 1 and Comparative Examples 1 and 2, respectively;
FIG. 2 is a graph showing charge and discharge cycles of a secondary battery including positive electrodes prepared according to Example 1 and Comparative Examples 1 and 2, respectively.

Hereinafter, although described in more detail with reference to some embodiments according to the present invention, the scope of the present invention is not limited thereto.

&Lt; Example 1 >

1-1. Preparation and Coating of Carbon Slurry

Super-P 65 (carbon) as a carbon-based material and polyvinylidene fluoride (PVdF: KF1100) as a binder were mixed at a weight ratio of 60:40, and N-methyl pyrrolidone (NMP) was added dropwise to the mixture. Slurry was prepared. The carbon slurry prepared above was coated on aluminum foil with a thickness of 20 μm and dried in an oven at 120 ° C. for 5 minutes.

1-2. Preparation and Coating of Anode Mixtures

A: (KF1100 PVdF) 90: LiNi 1/3 Mn 1/3 Co 1/3 O 2, as the conductive material as a Super-P 65 and a binder of polyvinylidene fluoride as a positive electrode active material were mixed at a weight ratio of 5: 5 N-methyl pyrrolidone (NMP) was added dropwise to the mixture to prepare an electrode mixture. The electrode mixture prepared above was applied to an aluminum foil coated with a carbon slurry, and dried at 120 ° C. for 10 minutes.

1-3. Perform roll pressing

Roll pressing was performed on the positive electrode manufactured by the steps 1-1 and 1-2.

&Lt; Comparative Example 1 &

After coating the carbon slurry and the electrode mixture on the aluminum foil, a positive electrode for a secondary battery was manufactured in the same manner as in Example 1 except that roll pressing was not performed.

Comparative Example 2

Roll pressing was performed after coating the carbon slurry on the aluminum foil, and the same method as in Example 1 except that the electrode mixture was coated on the carbon slurry coating layer on which the roll pressing was performed, and then roll pressing was performed again. To prepare a secondary battery positive electrode

<Experimental Example 1>

In order to compare the bonding strength of the positive electrode mixture to the current collector in the positive electrode according to Example 1 and Comparative Examples 1 and 2, each of the prepared positive electrode surface was cut to a fixed size and fixed on a slide glass, and then peeled off the aluminum foil. Peel strength was measured at 180 ℃, the results are shown in Table 1 below.

<Table 1>

As shown in Table 1, the positive electrode of Example 1 according to the present invention exhibits a higher adhesive force than the positive electrode of Comparative Examples 1 and 2. That is, it was found that the bonding force of the positive electrode mixture to the current collector was improved by roll pressing performed after continuously forming the carbon slurry layer and the electrode mixture layer on the current collector.

<Experimental Example 2>

Including the positive electrode prepared according to Example 1 and Comparative Examples 1 and 2, 1C cell capacity of the pouch type secondary battery (Polymer pouch type single layer cell) of 20mAh class was prepared, respectively.

As a negative electrode, a negative electrode slurry prepared by mixing natural graphite: CMC: SBR binder: carbon conductive material (super-C65) with 95: 1: 2: 2 was coated and dried on a copper foil having a thickness of 60 μm. In this case, unlike the positive electrode, no carbon slurry was applied. Polyethylene was used as the separator.

In the secondary battery manufactured above, cell resistance was measured by HPPC at room temperature (25 ° C.), and then the charge and discharge cycle characteristics of the same cell were measured at 45 ° C. under 1C / discharge 2C. And 2.

<Table 2>

According to Table 2 and FIGS. 1 and 2 below, the positive electrode of Example 1 is reduced in cell resistance by reducing the interfacial resistance between the positive electrode mixture and the current collector as compared with the positive electrodes of Comparative Examples 1 and 2, and thus the secondary battery including the same. Output characteristics can be improved. This resistance difference is more noticeable in a medium-large secondary battery using an increased number of cycles or a large amount of active material in one battery cell.

In addition, the positive electrode of Example 1 due to the high adhesion, the secondary battery including the same due to the mechanical stress due to the generation of gas by the side reaction during charging and discharging, by-product generation in the electrode mixture, and volumetric shrinkage expansion of the positive electrode active material itself, etc. Improved lifespan characteristics can also be demonstrated when contact degradation occurs between the whole and the electrode mixture.

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 (14)

a) an electrode mixture coating layer comprising an electrode mixture including an electrode active material, a binder, and a conductive material; And
b) a carbon slurry coating layer composed of a carbon slurry and coated on at least part of an interface between the electrode mixture coating layer and a current collector;
Secondary battery electrode comprising a.  The method of claim 1, wherein the carbon slurry is at least one carbon-based material selected from the group consisting of graphite, carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, carbon fiber and carbon fluoride, A secondary battery electrode comprising a polymer material as a binder. The method of claim 2, wherein the polymer material is polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluor A secondary battery electrode, characterized in that at least one selected from the group consisting of ethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene- butylene rubber and fluorine rubber.  The electrode of claim 2, wherein the carbon-based material is included in an amount of 20 to 80 wt% based on the total weight of the carbon slurry.  The method of claim 1, wherein the carbon slurry coating layer is a secondary battery electrode, characterized in that the thickness of 0.5 to 50 ㎛.  According to claim 1, wherein the carbon slurry coating layer is a secondary battery electrode, characterized in that formed in 50 to 100% based on the surface area of the current collector.  The method of claim 1, wherein the surface roughness of the carbon slurry coating layer (roughness) is a secondary battery electrode, characterized in that the size of 0.01 to 30 ㎛. The electrode for secondary batteries according to claim 1, wherein an interface between the carbon slurry coating layer and the electrode mixture coating layer has an uneven interface structure.  The method of claim 1, wherein the electrode mixture coating layer is a secondary battery electrode, characterized in that the thickness of 5 to 400 ㎛. The method of claim 1, wherein the density of the electrode is a secondary battery electrode, characterized in that 1.5 to 5 g / cc. As a method of manufacturing an electrode for secondary batteries according to claim 1,
a) coating a carbon slurry on a part or the entire surface of the current collector and drying to form a carbon slurry coating layer;
b) coating and drying an electrode mixture including an electrode active material, a binder, and a conductive material on the current collector on which the carbon slurry coating layer is formed to form an electrode mixture coating layer;
c) roll pressing the continuously coated carbon slurry coating layer and the electrode mixture coating layer;
d) applying the steps (a), (b) and (c) one or more times;
&Lt; / RTI &gt;  The method of claim 11, wherein the drying of step (a) and step (b) is carried out at 80 to 200 ℃ for 1 to 20 minutes. A secondary battery comprising the electrode according to claim 1 as a positive electrode, a negative electrode, or a positive electrode and a negative electrode. The secondary battery of claim 11, wherein the secondary battery is a lithium secondary battery.

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