KR101457544B1 - Anode Binder for Secondary Battery Providing Excellent Adhesion Strength and Life Characteristics - Google Patents

Abstract

The present invention provides a binder for a negative electrode of a secondary battery, wherein the 5% solution has a viscosity of 800 cps to 10,000 cps based on NMP solvent and contains a copolymer of a hydrophilic monomer and a hydrophobic monomer. Such a binder provides a secondary battery excellent in lifetime characteristics by fundamentally improving the stability of the negative electrode from the manufacturing process of the electrode.

Description

[0001] The present invention relates to an anode binder for a secondary battery,

More particularly, the present invention relates to a binder for a negative electrode of a secondary battery, which comprises a copolymer of a hydrophilic monomer and a hydrophobic monomer, wherein the viscosity of the 5% solution is 800 cps to 10000 cps based on NMP solvent To a negative electrode binder of a secondary battery.

Due to the rapid increase in the use of fossil fuels, the demand for the use of alternative energy or clean energy is increasing. As a part of this, the most active field of research is electric power generation and storage.

At present, a typical example of an electrochemical device utilizing such electrochemical energy is a secondary battery, and the use area thereof is gradually increasing.

2. Description of the Related Art [0002] Recently, as technology development and demand for portable devices such as portable computers, portable phones, and cameras have increased, the demand for secondary batteries as energy sources has increased sharply. Among such secondary batteries, they exhibit high energy density and operating potential, Many studies have been made on a lithium secondary battery having a long self discharge rate, and it has been commercialized and widely used.

In addition, as the interest in environmental problems grows, researches on electric vehicles and hybrid electric vehicles that can replace fossil fuel-based vehicles such as gasoline vehicles and diesel vehicles, which are one of the main causes of air pollution, . Although nickel-metal hydride secondary batteries are mainly used as power sources for such electric vehicles and hybrid electric vehicles, researches using lithium secondary batteries having high energy density and discharge voltage are being actively carried out, and they are in the commercialization stage.

Conventionally, a typical lithium secondary battery uses graphite as a negative electrode active material, charging and discharging proceed while repeating a process in which lithium ions in an anode are inserted into a negative electrode and desorbed. The theoretical capacity of the battery varies depending on the kind of the electrode active material, but the charging and discharging capacities decrease with the progress of the cycle.

This phenomenon is the biggest cause of the separation of the electrode active material or between the electrode active material and the current collector due to the change of the volume of the electrode caused by the progress of the charging and discharging of the battery, so that the active material fails to function. In addition, lithium ions inserted into the negative electrode may not be properly discharged during the insertion or desorption, and the active sites of the negative electrode may be reduced. As a result, the charge / discharge capacity and lifetime characteristics of the battery may decrease as the cycle progresses.

Particularly, in order to increase the discharge capacity, when a material such as silicon, tin, silicon-tin alloy, etc. having a large discharge capacity is used in combination with natural graphite having a theoretical discharge capacity of 372 mAh / g, The volume expansion of the material is remarkably increased, thereby causing the separation of the negative electrode material from the electrode material. As a result, the capacity of the battery is drastically lowered due to repeated cycles.

Therefore, it is possible to prevent separation between the electrode active material or between the electrode active material and the current collector during the production of the electrode with a strong adhesive force, and to control the volume expansion of the electrode active material generated during repetitive charging and discharging with strong physical properties, There is a great demand in the art for a study on a binder and an electrode material capable of improving the performance of the battery due to the above-mentioned problems.

Since polyvinylidene fluoride (PVdF), which is an organic solvent-based binder, does not satisfy the above requirements, recently, styrene-butadiene rubber (SBR) And a method of using it by mixing with a viscosity adjusting agent have been proposed and are now being used commercially. In the case of such a binder, it is environmentally friendly and has an advantage that the battery capacity can be increased by reducing the content of the binder.

However, in the case of conventional viscosity modifiers such as carboxy metyl cellulose, the viscosity is high and stable, but it is very rigid, thereby deteriorating the processability of the battery and increasing the electrical resistance, .

Therefore, there is a high demand for development of a binder having an improved adhesive strength and structural stability of the electrode while improving the life characteristics of the battery.

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.

The inventors of the present application have conducted intensive research and various experiments and have developed a binder for a negative electrode of a secondary battery comprising a copolymer of a hydrophilic monomer and a hydrophobic monomer having a predetermined viscosity as described below. It has been confirmed that when a negative electrode binder is used for a secondary battery, it can contribute to an improvement in a life characteristic while providing an excellent adhesive force, and the present invention has been accomplished.

Therefore, the binder for a negative electrode of a secondary battery according to the present invention has a viscosity of 5 to 10 weight percent based on a mixed solution of a binder and an NMP solvent of 800 cps to 10,000 cps.

Since the binder for a negative electrode according to the present invention includes a copolymer of a hydrophilic monomer and a hydrophobic monomer having a predetermined viscosity, it is possible to provide a binder for a flexible negative electrode having a high viscosity without using a viscosity adjusting agent in the course of manufacturing a battery have

The viscosity of the copolymer can be controlled by various factors such as the type and the molecular weight of the monomers constituting the copolymer. For example, in the exemplary monomers described below, the polymerization degree and the like can be selectively controlled, The viscosity of the predetermined range can be obtained in a predetermined solution.

In the present invention, such viscosity measurements are generally made by using a viscometer with the copolymer in a container.

The copolymer may have a viscosity of 30 cps to 700 cps in a 2 wt% solution based on a mixed solution of a binder and an NMP solvent.

In addition, the copolymer may have a viscosity of 50 cps to 500 cps and a viscosity of 5 wt% of the solution may be 1000 cps to 5000 cps, based on the mixed solution of the binder and the NMP solvent. Specifically, the viscosity of the 2 wt% solution based on the mixed solution of the binder and the NMP solvent may be 70 cps to 300 cps, and the viscosity of the 5 wt% solution may be 1600 cps to 4500 cps.

In one preferred example, the copolymer comprises 70 to 99% by weight of at least one monomer selected from the group consisting of (A) a monomer containing a nitrile group, based on the total weight of the binder, and (B) And 1 to 30% by weight of one or more monomers selected from the group consisting of monomers containing one or more monomers containing one or more monomers.

The content of the monomers contained in the copolymer is undesirable if it deviates from the defined range as a range for exerting optimum adhesive force, as can be seen in the following Experimental Examples.

The nitrile monomer may be selected from the group consisting of, for example, succinonitrile, sebaconitrile, fluorinated nitrile, a monomer group having a double bond including a nitrile chloride group, a group selected from the group consisting of acrylonitrile and methacrylonitrile Or more, but is not limited to these.

Examples of the monomer having a carboxylic acid group and an amide group include unsaturated monocarboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, glutaconic acid , And itaconic acid, and an acid anhydride thereof, acrylamide, n-methylol acrylamide, n-butoxymethylacrylamide, and methacrylamide, or a mixture thereof. Or more.

More preferably, the monomer containing the nitrile group may be acrylonitrile, and the monomer containing a carboxylic acid group and an amide group may be acrylic acid. In this case, the tensile strain of the copolymer of acrylonitrile and acrylic acid may be 5 to 100%.

In some cases, the copolymer may further contain a (meth) acrylic acid ester monomer, a conjugated diene monomer, and / or a vinyl monomer. In this case, the added monomers may range from 0.1 to 20% by weight based on the total monomer weight.

The (meth) acrylic acid ester monomer may be, for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, Ethylhexyl acrylate, hydroxypropyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, meta Acrylate, n-amyl acrylate, isoamyl methacrylate, n-hexyl methacrylate, n-ethylhexyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate May be at least one monomer selected from the group consisting of

The conjugated diene monomer may be at least one monomer selected from the group consisting of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene .

The vinyl monomer may be, for example, styrene, o-, m-, and p-methylstyrene,? -Methylstyrene,? -Methylstyrene, 2,4-dimethylstyrene, o-, m-, Ethylstyrene, pt-butylstyrene, divinylbenzene, and vinylnaphthalene.

The negative electrode binder according to the present invention can be produced, for example, by emulsion polymerization, suspension polymerization, precipitation polymerization and solvent polymerization using the above monomers. The polymerization temperature and the polymerization time may be appropriately determined according to the polymerization method and the kind of the polymerization initiator to be used. For example, the polymerization temperature may be about 50 캜 to 200 캜, and the polymerization time may be about 1 to 20 hours .

As the polymerization initiator, an inorganic or organic peroxide may be used. For example, a water-soluble initiator including potassium persulfate, sodium persulfate, ammonium persulfate and the like and a viscosity initiator including cumene hydroperoxide, benzoyl peroxide, Can be used. The polymerization initiator may further include an activating agent to promote the initiating reaction of the peroxide with the polymerization initiator. Examples of the activating agent include sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate and dextrose At least one selected from the group consisting of

The present invention also provides a negative electrode for a secondary battery, wherein the negative electrode active material and the conductive material are bonded to the current collector by the negative electrode binder described above.

Such an anode can be prepared by preparing a slurry by adding a binder for a negative electrode, a negative electrode active material and a conductive material to a predetermined solvent such as water or NMP, applying the slurry to a collector, followed by drying and rolling. The negative electrode active material will be described later in more detail.

In the case of the positive electrode, a mixture of a positive electrode active material, a conductive material, a positive electrode binder and the like is coated on the positive electrode current collector, followed by drying.

The positive electrode active material is a lithium transition metal oxide. The lithium-transition metal oxide is a layered compound such as lithium cobalt oxide (LiCoO ₂ ) and lithium nickel oxide (LiNiO ₂ ), which contains two or more transition metals and is substituted with, for example, one or more transition metals ; Lithium manganese oxide substituted with one or more transition metals; Formula _{LiNi 1-y M y O 2} ( where, M = Co, Mn, Al , Cu, Fe, Mg, B, Cr, Zn or Ga and Lim, 0.01≤y≤0.7 include one or more elements of the element) A lithium nickel-based oxide represented by the following formula: _{Li 1 + z Ni 1/3 Co 1/3} Mn 1/3 O 2, Li 1 + z Ni 0.4 Mn 0.4 Co 0.2 O 2 , such as _{Li 1 + z Ni b Mn c} Co 1- (b + c + d _{) M d O (2-e} ) A e ( where, -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2 , 0≤e≤0.2, b + c + d <1, M = Al, Mg, Cr, Ti, Si or Y, and A = F, P or Cl; lithium nickel cobalt manganese composite oxide; Formula Li _{1 + x} M _{1 -} and _{y M 'y PO 4 -z X} z ( wherein, M = a transition metal, preferably Fe, Mn, Co or Ni, M' = Al, Mg or Ti, X = F, S or N, and -0.5? X? +0.5, 0? Y? 0.5, and 0? Z? 0.1), but the present invention is not limited thereto.

Examples of the negative electrode active material include carbon and graphite materials such as natural graphite, artificial graphite, expanded graphite, carbon fiber, non-graphitizable carbon, carbon black, carbon nanotube, fullerene and activated carbon; Metals such as Al, Si, Sn, Ag, Bi, Mg, Zn, In, Ge, Pb, Pd, Pt and Ti which can be alloyed with lithium and compounds containing these elements; Complexes of metals and their compounds and carbon and graphite materials; Lithium-containing nitrides, and the like. Among them, a carbon-based active material, a silicon-based active material, a tin-based active material, or a silicon-carbon based active material is more preferable, and these may be used singly or in combination of two or more.

The conductive material is a component for further improving the conductivity of the electrode active material and may be added in an amount of 0.01 to 30% by weight based on the total weight of the electrode mixture. 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; Carbon fibers such as carbon nanotubes and fullerene; conductive fibers such as carbon fibers and metal fibers; 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 positive electrode binder is a component that assists in bonding of the active material to 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 including the negative electrode 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 electrode is a portion where electrons move in the electrochemical reaction of the active material, and the positive electrode collector and the negative electrode collector exist depending on the type of the electrode.

The cathode current collector is generally made to have 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 change in the battery, and may be formed of a material such as stainless steel, aluminum, nickel, titanium, sintered carbon, or a surface of aluminum or stainless steel Treated with carbon, nickel, titanium, silver or the like may be used.

The 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 conductivity without causing chemical change in the battery, and may be formed of a material such as copper, stainless steel, aluminum, nickel, titanium, fired carbon, surface of copper or stainless steel A surface treated with carbon, nickel, titanium, silver or the like, an aluminum-cadmium alloy, or the like can be used.

These current collectors have a thickness of 3 to 200 mu m and can be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.

In some cases, a filler may be further included in the mixture (electrode mixture) of the electrode active material, the conductive material, the binder and the like.

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

The present invention also provides a lithium secondary battery including the negative electrode for the secondary battery.

The lithium secondary battery generally comprises a separator and a non-aqueous electrolyte containing a lithium salt in addition to the electrode.

The separator is an insulating thin film interposed between the anode and the cathode and having high ion permeability and mechanical strength. The pore diameter of the separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 300 mu m. As such a separation membrane, for example, a sheet or a nonwoven fabric made of an olefin-based polymer such as polypropylene which is chemically resistant and hydrophobic, 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-containing non-aqueous electrolyte is composed of a non-aqueous electrolyte and a lithium salt.

Examples of the nonaqueous electrolytic solution include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, But are not limited to, lactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, Nitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, trimethoxymethane, dioxolane derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives , Tetrahydrofuran derivatives, ether, methyl pyrophosphate, ethyl propionate and the like can be used.

The lithium salt is a material which is soluble in the non-aqueous liquid electrolyte and includes, 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.

In some cases, organic solid electrolytes, inorganic solid electrolytes, etc. may 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.

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, , Nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 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 secondary battery according to the present invention can be suitably used as an electric power source for an electric vehicle, a hybrid electric vehicle, a power storage device and the like which require a long cycle characteristic and a long life characteristic.

As described above, the binder for a negative electrode of a secondary battery according to the present invention includes a copolymer satisfying a predetermined viscosity condition, and can exhibit an improved life characteristic while providing a high adhesive force with a minimum use of a viscosity adjusting agent .

Hereinafter, the present invention will be described in detail with reference to Examples and the like, but the scope of the present invention is not limited thereto.

[Example 1]

95 g of acrylonitrile and 5 g of acrylamide as monomers were added to water containing potassium persulfate as a polymerization initiator and they were mixed and polymerized at a temperature of 70 캜 for about 5 hours to obtain a negative electrode binder for a secondary battery .

[Example 2]

A binder for a negative electrode of a secondary battery was produced in the same manner as in Example 1 except that acrylic acid was used instead of acrylamide as a monomer.

[Example 3]

A negative electrode binder for a secondary battery was prepared using the same method as in Example 1 except that 90 g of acrylonitrile and 10 g of acrylic acid were used as monomers.

[Example 4]

A binder for a negative electrode of a secondary battery was produced in the same manner as in Example 1 except that 90 g of acrylonitrile and 10 g of acrylamide were used as monomers.

[Example 5]

A negative electrode binder for a secondary battery was produced using the same method as in Example 1 except that 5 g of styrene was further used as a monomer.

[Comparative Example 1]

A binder for a negative electrode of a secondary battery was prepared using the same method as in Example 1 except that the amount of the polymerization initiator was increased by three times and polymerization was carried out at a temperature of 80 캜 for about 5 hours.

[Comparative Example 2]

A binder for a negative electrode of a secondary battery was produced in the same manner as in Example 1 except that the amount of the polymerization initiator was reduced to half and polymerization was carried out at a temperature of 60 캜.

[Comparative Example 3]

A binder for a negative electrode of a secondary battery was produced in the same manner as in Example 1, except that acrylonitrile alone was used as a monomer.

[Comparative Example 4]

Polyvinylidene fluoride was prepared as a negative electrode binder of a secondary battery.

[Experimental Example 1] Viscosity measurement

The binder of the negative electrode of the secondary battery according to the present invention was dissolved in NMP to prepare a 2% solution of 5% solution, and the viscosity of the solution was measured.

[Table 1]

[Experimental Example 2] Adhesion test

The adhesive force between the electrode active material and the current collector was measured using the negative electrode binder of the secondary battery according to the present invention.

First, a binder according to the above-described Examples and Comparative Examples was added so that the ratio of the anode active material (silicon-carbon based active material), the conductive material and the binder was 95: 1: 4, Was coated on a Cu foil, dried in an oven at 130 ° C for 30 minutes, and dried in an oven at 110 ° C for 12 hours to prepare a negative electrode. The prepared negative electrode was pressed, and the surface was cut and fixed on a slide glass. Then, a 180-degree peel strength was measured while peeling the collector, and the results are shown in Table 2 below. The evaluation was made by measuring the peel strengths of 5 or more and calculating the average value.

[Table 2]

As shown in Table 2, it can be seen that the cathodes using the binders of the embodiments of the present invention exhibit higher adhesive force than the cathodes using the binders of the comparative examples.

[Experimental Example 3] Life characteristics test

A coin type lithium secondary battery was fabricated from the electrode prepared in Experimental Example 2 and lithium metal. The thus prepared coin-type lithium secondary battery was charged at 0.1 C in a voltage range of 0 to 1 V, discharged at 0.1 C, and then charged and discharged at 1 C for 50 cycles to measure the lifetime characteristics. The results are shown in Table 3 below.

[Table 3]

As shown in Table 3, the batteries manufactured according to the embodiments of the present invention are superior in life characteristics to the batteries manufactured according to the comparative examples. In the case of Comparative Example 2, although the adhesive strength was greatly improved, it was confirmed that the internal resistance was large and the life characteristics were much lower than those in Examples.

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 (11)

A binder for a negative electrode of a secondary battery, comprising a copolymer having a viscosity of from 5,000 to 5,000,000 cps based on a mixed solution of a binder and an NMP solvent, wherein the copolymer has (a) 1 to 30% by weight of at least one monomer selected from the group consisting of monomers containing carboxylic acid groups and amide groups, and (b) from 70 to 99% by weight of at least one monomer selected from the group consisting of And a binder for a negative electrode of a secondary battery. The binder for a negative electrode of a secondary battery according to claim 1, wherein the copolymer has a viscosity of 30 cps to 700 cps in a 2 wt% solution based on a mixed solution of a binder and an NMP solvent. The binder for a negative electrode of a secondary battery according to claim 1, wherein the copolymer has a viscosity of 5 cps to 5000 cps based on a mixed solution of a binder and an NMP solvent. The binder for a negative electrode of a secondary battery according to claim 1, wherein the copolymer has a viscosity of 50 cps to 500 cps in a 2 wt% solution based on a mixed solution of a binder and an NMP solvent. delete The method of claim 1, wherein the monomer comprising the nitrile group is selected from the group consisting of succinonitrile, cevanonitrile, fluoronitrile, a monomer having a double bond comprising nitrile, acrylonitrile and methacrylonitrile Wherein the binder is one or more kinds of monomers. The composition according to claim 1, wherein the monomer containing a carboxylic acid group and an amide group is an unsaturated monocarboxylic acid monomer selected from acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, citraconic acid, Unsaturated dicarboxylic acid monomers selected from the group consisting of rutaconic acid, itaconic acid, acid anhydrides of the unsaturated monocarboxylic acid monomers, acid anhydrides of the unsaturated dicarboxylic acid monomers, acrylamide, n-methylol acrylamide, n- Wherein the binder is at least one monomer selected from the group consisting of methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, The negative electrode binder for a secondary battery according to claim 1, wherein the monomer containing nitrile group is acrylonitrile, and the monomer containing carboxylic acid group and amide group is acrylic acid and has a tensile strain of 5 to 100% . The negative electrode for a secondary battery according to any one of claims 1 to 4 and 6 to 8, wherein the negative electrode active material and the conductive material are bonded to the current collector by the negative electrode binder of the secondary battery. The negative electrode for a secondary battery according to claim 9, wherein the electrode current collector has a thickness of 3 to 200 탆. A lithium secondary battery comprising the negative electrode for a secondary battery according to claim 10.