Positive electrode slurry composition, positive electrode, and lithium secondary battery comprising same

Abstract

The present invention relates to a positive electrode slurry composition, a positive electrode, and a lithium secondary battery comprising same and relates specifically to: a positive electrode slurry composition for a lithium secondary battery, which includes a positive electrode active material, a film-forming additive, and a solvent, wherein the film-forming additive is a compound represented by chemical formula 1; a positive electrode for a lithium secondary battery; and a lithium secondary battery comprising same.

Description

Anode slurry composition, anode, and lithium secondary battery containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0125221 filed September 12, 2024 and Korean Patent Application No. 10-2025-0124482 filed September 2, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003]

[0004] Technology field

[0005] The present invention relates to an anode slurry composition, an anode, and a lithium secondary battery in which gas generation caused by side reactions between the anode and the electrolyte is reduced by including the same.

[0006] With the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly rising. Among these secondary batteries, lithium secondary batteries, which exhibit high energy density and operating potential, long cycle life, and low self-discharge rate, have been commercialized and are widely used.

[0007] Meanwhile, as the application range of lithium secondary batteries expands to include not only portable power sources such as mobile phones, laptop computers, digital cameras, and camcorders, but also medium and large power sources such as power tools, electric bicycles, hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), high driving voltages are required to achieve high energy density.

[0008] However, when operating continuously under high voltage, not only is the electrolyte depleted due to oxidative decomposition reactions between the anode and the electrolyte, but the breakdown of the passivation film on the electrode surface also leads to problems such as gas generation from electrolyte side reactions and the leaching of transition metals from the anode, resulting in a deterioration of the battery's long-life performance. These problems are exacerbated or accelerated by exothermic reactions generated during battery operation.

[0009] Accordingly, there is a need to develop lithium secondary batteries capable of achieving high energy density by forming a stable passivation film on the electrode surface during high-voltage operation, thereby suppressing gas generation caused by side reactions in the electrolyte and inhibiting the leaching of transition metals from the anode.

[0010] One objective of the present invention is to solve the above-mentioned problems by providing an anode slurry composition comprising a uracil-based compound capable of first forming a highly durable film on the surface of the anode.

[0011] In addition, another objective of the present invention is to provide an anode comprising an anode composite layer containing a film-forming additive capable of forming a highly durable film on the surface of the anode.

[0012] In addition, another objective of the present invention is to provide a lithium secondary battery comprising the aforementioned positive electrode.

[0013] [1] The present invention provides a positive electrode slurry composition for a lithium secondary battery comprising a positive electrode active material, a film-forming additive, and a solvent, wherein the film-forming additive is a compound represented by the following chemical formula 1.

[0014] [Chemical Formula 1]

[0015]

[0016] In the above chemical formula 1,

[0017] R1 is -SO2F, -OSO2N(R a )(R b), -SO2R c , -OLi or -OR', where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c is a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine, and R' is a carbon-1 to carbon-10 alkyl group.

[0018] [2] The present invention is, in [1] above, wherein in Chemical Formula 1, R1 is -SO2F, -OSO2N(R a )(R b ) or -SO2Rc, where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c The present invention provides a positive electrode slurry composition for a lithium secondary battery, wherein the alkyl group having 1 to 5 carbon atoms is substituted or unsubstituted with fluorine.

[0019] [3] The present invention is, in [1] or [2] above, wherein in Formula 1, R1 is -SO2F, -OSO2N(R a )(R b ) or -SO2Rc, where R a and R b are independently alkyl groups having 1 to 3 carbon atoms, and R c The present invention provides a positive electrode slurry composition for a lithium secondary battery, wherein the alkyl group having 1 to 3 carbon atoms is substituted or unsubstituted with fluorine.

[0020] [4] The present invention provides a positive electrode slurry composition for a lithium secondary battery, wherein, in at least one of [1] to [3], the compound represented by Formula 1 is at least one of the compounds represented by Formulas 1A to 1G below:

[0021] [Chemical Formula 1A]

[0022]

[0023] [Chemical Formula 1B]

[0024]

[0025] [Chemical Formula 1C]

[0026]

[0027] [Chemical Formula 1D]

[0028]

[0029] [Chemical Formula 1E]

[0030]

[0031] [Chemical Formula 1F]

[0032]

[0033] [Chemical Formula 1G]

[0034] .

[0035] [5] The present invention provides a positive electrode slurry composition for a lithium secondary battery, wherein, in at least one of [1] to [4], the film-forming additive is included in an amount of 0.004% to 10% by weight based on the total weight of the solid content of the positive electrode slurry composition.

[0036] [6] The present invention provides a positive electrode slurry composition for a lithium secondary battery, wherein, in at least one of [1] to [5], the film-forming additive is included in an amount of 0.1% to 8.0% by weight based on the total weight of the solid content of the positive electrode slurry composition.

[0037] [7] The present invention provides an anode slurry composition comprising, in at least one of [1] to [6], a positive active material comprising a compound represented by the following chemical formula 2:

[0038] [Chemical Formula 2]

[0039] Li 1+a Ni x Co y M 1 z M 2 w O2

[0040] In the above chemical formula 2,

[0041] M 1 is Mn, Al, or a combination thereof, and

[0042] M 2 is at least one selected from the group consisting of Al, Zr, W, Ti, Mg, Ca, and Sr, and 0≤a≤0.5, 0 <x<1.0, 0<y≤0.4, 0<z≤0.4, 0≤w≤0.1 이며, x+y+z+w는 1일 수 있다.

[0043] [8] The present invention provides a positive electrode slurry composition for a lithium secondary battery, wherein, in at least one of [1] to [7], the positive electrode slurry composition for a lithium secondary battery further comprises at least one of a conductive material, a binder, and a thickener.

[0044] [9] The present invention provides a positive electrode for a lithium secondary battery comprising a positive electrode active material and a film-forming additive, wherein the film-forming additive is a compound represented by the following chemical formula 1:

[0045] [Chemical Formula 1]

[0046]

[0047] In the above chemical formula 1,

[0048] R1 is -SO2F, -OSO2N(R a )(R b ), -SO2R c , -OLi or -OR', where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c is a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine, and R' is a carbon-1 to carbon-10 alkyl group.

[0049]

[0010] The present invention provides an anode in which the anode composite layer comprises a urea-containing film, in accordance with [9].

[0050]

[0011] The present invention provides a method for manufacturing a positive electrode for a secondary battery, comprising the steps of: applying a positive electrode slurry composition onto a positive electrode current collector; and drying and rolling the positive electrode slurry composition to form a positive electrode composite layer, wherein the positive electrode slurry composition is the positive electrode slurry composition of [1].

[0051]

[0012] The present invention provides a lithium secondary battery comprising a positive electrode according to [9]; a negative electrode opposite to the positive electrode; and an electrolyte.

[0052] As described above, the positive electrode slurry composition for a lithium secondary battery according to the present invention includes a uracil-based compound as a film-forming additive, thereby forming a solid urea-containing film on the surface of the positive electrode during initial charging, which can prevent adverse reactions at the interface between the positive electrode and the electrolyte and suppress oxygen desorption from the positive electrode.

[0053] In addition, lithium secondary batteries containing such a cathode can effectively improve electrochemical performance, such as high-temperature life characteristics and high-temperature storage performance, by suppressing gas generation and transition metal leaching from the cathode during operation.

[0054] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0055]

[0056] The present invention will be described in detail below.

[0057] A positive electrode for a lithium secondary battery, a method for manufacturing a positive electrode, and a lithium secondary battery comprising a positive electrode slurry composition, a positive electrode active material, and a positive electrode composite layer comprising a film-forming additive according to the present invention, comprises at least one of the configurations disclosed below and may comprise any combination of technically feasible configurations among the configurations below.

[0058]

[0059] Anode slurry composition for lithium secondary batteries

[0060] The positive electrode slurry composition for a lithium secondary battery according to the present invention

[0061] It comprises a positive electrode active material, a film-forming additive, and a solvent, wherein the film-forming additive may be a compound represented by the following chemical formula 1.

[0062] [Chemical Formula 1]

[0063]

[0064] In the above chemical formula 1,

[0065] R1 is -SO2F, -OSO2N(R a )(R b ), -SO2R c , -OLi or -OR', where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c is a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine, and R' is a carbon-1 to carbon-10 alkyl group.

[0066]

[0067] (1) Positive active material

[0068] The positive electrode active material of the present invention is a compound capable of reversible intercalation and deintercalation of lithium, and specifically, may include a lithium composite metal oxide comprising lithium and one or more metals such as cobalt, manganese, nickel, or aluminum.

[0069] Specifically, the above-mentioned positive electrode active material is a lithium-cobalt-based oxide (e.g., LiCoO2, etc.), a lithium-manganese-based oxide (e.g., LiMnO2, LiMn2O4, etc.), a lithium-nickel-based oxide (e.g., LiNiO2, etc.), or a lithium-nickel-manganese-based oxide (e.g., LiNi 1-Y Mn Y O2(here, 0 <Y<1), LiMn 2-z Ni z O4 (where 0 < Z < 2), etc.), lithium-nickel-cobalt oxides (e.g., LiNi 1-Y1 Co Y1 O2(here, 0 <Y1<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo 1-Y2 Mn Y2 O2(here, 0 <Y2<1), LiMn 2-z1 Co z1 O4 (where 0 < Z1 < 2), etc.), lithium-nickel-manganese-cobalt oxide or Li(Ni p1 Co q1 Mn r2 )O4(where 0<p1<2, 0<q1<2, 0<r2<2, p1+q1+r2=2) etc.), lithium-nickel-cobalt-transition metal (M) oxide (e.g., Li(Ni p2 Co q2 Mn r3 M S2 It may include )O2(wherein M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg, Ti and Mo, and p2, q2, r3 and s2 are each atomic fractions of independent elements, 0<p2<1, 0<q2<1, 0<r3<1, 0<s2<1, p2+q2+r3+s2=1)), and any one or more of these compounds may be included.

[0070] Among these, in terms of increasing the capacity characteristics and stability of the battery, the positive electrode active material may include at least one selected from the group consisting of lithium-cobalt oxide, lithium-manganese-based oxide, and lithium-nickel-manganese-cobalt-based oxide represented by the following chemical formula 2.

[0071] [Chemical Formula 2]

[0072] Li 1+a Ni x Co y M 1 z M 2 w O2

[0073] In the above chemical formula 2,

[0074] M 1 is Mn, Al, or a combination thereof, and

[0075] M 2 is at least one selected from the group consisting of Al, Zr, W, Ti, Mg, Ca, and Sr, and 0≤a≤0.5, 0 <x<1.0, 0<y≤0.4, 0<z≤0.4, 0≤w≤0.1 이며, x+y+z+w는 1일 수 있다.

[0076] The above 1+a represents the atomic fraction of lithium in the lithium transition metal oxide, and may be 0≤a≤0.5, preferably 0≤a≤0.2, more preferably 0≤a≤0.1.

[0077] The above x represents the atomic fraction of nickel among the total transition metal elements in the lithium transition metal oxide, and 0 <x<1.0, 구체적으로 0.55<x≤0.98, 더욱 구체적으로는 0.6≤x≤0.98, 보다 더 구체적으로는 0.6≤x≤0.95일 수 있다.

[0078] The above y represents the atomic fraction of cobalt among the total transition metal elements in the lithium transition metal oxide, and 0 <y≤0.4, 구체적으로 0<y≤0.3, 더욱 구체적으로는 0.05≤y≤0.3일 수 있다.

[0079] The above z is M among the total transition metal elements in the lithium transition metal oxide. 1 Represents the atomic fraction of an element, and 0 <z≤0.4, 바람직하게는 0<z≤0.3, 더 바람직하게는 0.01≤z≤0.3일 수 있다.

[0080] The above w is M among the total transition metal elements in the lithium transition metal oxide. 2 Represents the atomic fraction of an element, and 0 <w≤0.1, 바람직하게는 0<w≤0.05, 더 바람직하게는 0<w≤0.02이다.

[0081] Specifically, in order to realize a high-capacity battery, the above-mentioned cathode active material may include a lithium composite transition metal oxide having a Ni content of 0.55 atm% or more relative to the total number of metal elements excluding lithium. More specifically, the above-mentioned cathode active material is Li(Ni 0.6 Mn 0.2 Co 0.2 )O2, Li(Ni) 0.6 Mn 0.3 Co 0.1 )O2, Li(Ni) 0.7 Mn 0.15 Co 0.15 )O2, Li(Ni 0.7 Mn 0.2 Co 0.1 )O2, Li(Ni 0.8 Mn 0.1 Co 0.1 )O2, Li(Ni 0.8 Co 0.15 Al 0.05 )O2, Li(Ni 0.86 Mn 0.07 Co 0.05 Al 0.02 )O2 or Li(Ni 0.90 Mn 0.05 Co 0.05 It may include O2, etc.

[0082] The above-mentioned positive active material may be included in an amount of 80 to 108 weight%, more specifically 85 to 108 weight%, based on the total weight of the solids included in the positive slurry composition. When the positive active material is included in the above range, excellent capacity characteristics can be secured, and excellent flowability, conductivity, or physical properties of the positive slurry composition can be obtained.

[0083]

[0084] (2) Film-forming additive

[0085] The anode slurry composition of the present invention may include a film-forming additive so as to form a urea-based film on the surface of the anode.

[0086] The above film-forming additive may be a compound represented by the following chemical formula 1.

[0087] [Chemical Formula 1]

[0088]

[0089] In the above chemical formula 1,

[0090] R1 is -SO2F, -OSO2N(R a )(R b ), -SO2R c , -OLi or -OR', where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c is a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine, and R' is a carbon-1 to carbon-10 alkyl group.

[0091]

[0092] Specifically, the compound represented by Chemical Formula 1, which contains a uracil group in its structure, can form a polymeric film containing one or more polycarbonate units on the electrode surface by reacting with a carbonate-based compound, which is an electrolyte solvent, and / or a Lewis acid (HF) contained in the electrolyte, after the ring structure is decomposed by breaking the -NC- single bond in the -NC=O portion during initial charging.

[0093] When the compound represented by Chemical Formula 1 is used simply as an electrolyte additive, the film-forming effect on the anode surface may be reduced as the compound represented by Chemical Formula 1 is consumed first on the cathode surface during initial charging and discharging. In addition, there is a problem in that the initial resistance increases and a sufficient amount of anode film cannot be formed because the preemptive decomposition of the compound represented by Chemical Formula 1 in the electrolyte is induced at the cathode, causing a film to form on the cathode surface. Furthermore, there is a problem in that uracil in the form of radicals reduced at the cathode is reoxidized at the anode surface, generating by-products, forming complexes with metals leached from the anode, and then moving to the cathode to induce another by-product.

[0094] To improve these problems, the present invention may include a compound represented by Chemical Formula 1 as a film-forming additive in the positive electrode active material slurry. That is, in the present invention, by including a compound represented by Chemical Formula 1 as an additive in the positive electrode active material slurry, a urea-containing film is preemptively formed on the surface of the positive electrode during battery operation, thereby preventing the leaching of metal elements, and since a film can be formed on the surface of the positive electrode first, an excessive film-forming reaction on the surface of the negative electrode is prevented, thereby preventing an increase in initial resistance and simultaneously improving the high-voltage performance of the cell.

[0095] Therefore, while improving the increase in initial resistance during battery operation, it is possible to effectively prevent side reactions at the interface between the anode and the electrolyte, suppress oxidative decomposition reactions of the electrolyte, and suppress oxygen desorption and transition metal leaching from the anode active material, thereby enabling significant improvements in electrochemical performance such as high-temperature life characteristics and high-temperature storage performance of the lithium secondary battery.

[0096] In particular, the compound represented by Chemical Formula 1 above has the advantage of having a high electron interaction, as the substituent (R1) directly bonded to the uracil group (core) is a functional group containing a sulfonyl group (-SO2-) or an oxy group (-O-), and a resonance structure is formed between the uracil group and the functional group. For example, compared to the case where a uracil-based compound directly substituted with an alkyl group, a fluorine group, an amino group, etc., such as the compound represented by Chemical Formula 3 below, is used as a film-forming additive, when the compound represented by Chemical Formula 1 of the present invention is included, the ring-opening reaction of the uracil group is promoted, thereby allowing for the faster formation of a robust urea-containing film with enhanced Li ion properties on the anode surface.

[0097] [Chemical Formula 3]

[0098]

[0099] (In the above Chemical Formula 3, Ro is a fluorine-substituted or unsubstituted alkyl group, -F or -NH2)

[0100] Specifically, in the above Chemical Formula 1, R1 is -SO2F, -OSO2N(R a )(R b ) or -SO2Rc, where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c can be a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine.

[0101] Or, in the above Chemical Formula 1, R1 is -SO2F, -OSO2N(R a )(R b ) or -SO2Rc, where R a and R b are independently alkyl groups having 1 to 3 carbon atoms, and R c can be a carbon-1 to carbon-3 alkyl group substituted or unsubstituted with fluorine.

[0102] Specifically, the compound represented by the above chemical formula 1 may be at least one of the compounds represented by the following chemical formulas 1A to 1G, and preferably may be at least one of the compounds represented by the following chemical formulas 1A to 1D and 1G that include a sulfonyl group in their structure.

[0103] [Chemical Formula 1A]

[0104]

[0105] [Chemical Formula 1B]

[0106]

[0107] [Chemical Formula 1C]

[0108]

[0109] [Chemical Formula 1D]

[0110]

[0111] [Chemical Formula 1E]

[0112]

[0113] [Chemical Formula 1F]

[0114]

[0115] [Chemical Formula 1G]

[0116]

[0117]

[0118] The film-forming additive may be included in an amount of 0.004 wt% or more, 0.01 wt% or more, 0.03 wt% or more, 0.05 wt% or more, 0.07 wt% or more, 0.09 wt% or more, or 0.1 wt% or more, based on the total weight of the solids of the anode slurry composition. Additionally, the film-forming additive may be included in an amount of 10 wt% or less, 9.0 wt% or less, 8.0 wt% or less, 7.0 wt% or less, 6.0 wt% or less, or 5.0 wt% or less, based on the total weight of the solids of the anode slurry composition. When the content of the film-forming additive satisfies the above range, the film-forming additive prevents side reactions and forms a solid film on the surface of the anode, thereby suppressing the oxidative decomposition reaction between the anode and the electrolyte, reducing gas generation, and suppressing oxygen desorption from the anode. The above numerical ranges can be combined without limitation and, specifically, may be included in amounts of 0.004 wt% to 10 wt%, 0.01 wt% to 8 wt%, 0.1 wt% to 8 wt%, or 0.1 wt% to 5.0 wt%. That is, if the content of the film-forming additive is 0.004 wt% or more, a solid film can be formed on the surface of the positive electrode during the battery operating time, and if it is 10 wt% or less, side reactions caused by the film-forming additive can be prevented, and a thick film formed on the surface of the positive electrode can be prevented from causing an increase in resistance.

[0119]

[0120] (3) solvent

[0121] In the anode slurry composition of the present invention, the solvent may be an organic solvent and / or an aqueous solvent commonly used in the art.

[0122] Specifically, the organic solvent may be at least one of N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), isopropyl alcohol, acetone, methoxypropyl acetate, butyl acetate, glycol acid, butyl ester, butyl glycol, methylalkyl polysiloxane, alkylbenzene, propylene glycol, xylene, monophenyl glycol, aralkyl-modified methylalkyl polysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyether-modified dimethylpolysiloxane copolymer, polyacrylate, alkylbenzene, diisobutyl ketone, organic-modified polysiloxane, butanol, isobutanol, modified polyacrylate, modified polyurethane, and polysiloxane-modified polymer. Additionally, the aqueous solvent may include water.

[0123] The amount of the above solvent used is sufficient to ensure that the anode slurry composition has an appropriate viscosity, taking into account the coating thickness of the anode composite layer, manufacturing yield, workability, etc., and is not particularly limited.

[0124]

[0125] Meanwhile, the positive electrode slurry composition for a lithium secondary battery according to the present invention may optionally further include at least one of a conductive material, a binder, and a thickener as needed.

[0126]

[0127] (4) Challenge material

[0128] Specifically, the conductive material is used to impart conductivity to the electrode, and in the battery being constructed, it may be used without special limitations as long as it has electronic conductivity without causing chemical changes. Specific examples of the conductive material include carbon black such as acetylene black (or Denka black), Ketjen black, channel black, furnace black, lamp black, or thermal black; graphite powder such as natural graphite, artificial graphite, or graphite with a highly developed crystal structure; conductive fibers such as carbon fibers or metal fibers; conductive powders such as carbon fluoride powder, aluminum powder, or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; polyphenylene derivatives, etc., and one of these alone or a mixture of two or more may be used.

[0129] The conductive material may be included in an amount of 0.1 to 10.0 weight%, preferably 1.0 to 8.0 weight%, based on the total weight of the solids included in the anode slurry composition. When the content of the conductive material satisfies the above range, the conductivity of the anode can be improved and the reduction of the flexibility of the anode can be prevented.

[0130]

[0131] (5) Binder

[0132] The above binder serves to improve adhesion between positive active material particles and adhesion between the positive active material and the current collector. Examples of such binders include fluoropolymer-based binders comprising polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); rubber-based binders comprising styrene butadiene rubber (SBR), acrylonitrile-butadiene rubber, or styrene-isoprene rubber; cellulose-based binders comprising carboxyl methyl cellulose (CMC), starch, hydroxypropyl cellulose, or regenerated cellulose; polyalcohol-based binders comprising polyvinyl alcohol; polyolefin-based binders comprising polyethylene or polypropylene; polyimide-based binders; and polyester-based binders. One type of silane binder alone or a mixture of two or more types may be used.

[0133] The above binder may be included in the anode composite layer in an amount of 0.1 to 15 weight%, preferably 0.1 to 10 weight%, based on the total weight of the solid content of the anode slurry composition. When the content of the binder is at the level described above, it is possible to prevent a decrease in the capacity of the anode while sufficiently securing the bonding strength of the anode active material, anode current collector, etc.

[0134]

[0135] (6) Thickener

[0136] In addition, the above-mentioned thickener can ensure the stability of the anode slurry composition by imparting appropriate viscosity to the anode slurry composition, and can improve surface defects by mitigating the phenomenon of re-aggregation of solids when the anode slurry composition is coated on the anode current collector.

[0137] The above-mentioned thickener may include carboxymethyl cellulose (CMC).

[0138] The above-mentioned thickener may be included in an amount of 0.5% to 5% by weight based on the total weight of the solid content of the anode slurry composition. If the content of the thickener is less than 0.5% by weight, the viscosity of the anode slurry composition is low and it flows down like water, so the anode slurry composition cannot be coated on the anode current collector, and if it exceeds 5% by weight, the viscosity is high and it is stiff, so it may be difficult to form a uniform coating layer.

[0139] Meanwhile, the viscosity of the anode slurry composition of the present invention is not particularly limited and may vary depending on the content of solids in the composition, but considering the phase stability of the anode slurry composition and the ease of the coating process, it may be 1000 cP or more or 4500 cP or more at 25°C.

[0140]

[0141] anode

[0142] In addition, the present invention includes a positive electrode, specifically a positive electrode for a lithium secondary battery.

[0143] Specifically, the present invention provides a positive electrode for a lithium secondary battery that may include a positive electrode composite layer comprising a positive electrode active material and a film-forming additive, wherein the film-forming additive is a compound represented by the chemical formula 1.

[0144] That is, the anode composite layer may be formed from the anode slurry composition of the present invention described above.

[0145] The above positive active material may be included in the above positive composite layer in an amount of 80% to 99% by weight, more specifically 85% to 98% by weight.

[0146] The above film-forming additive may be a compound represented by the above chemical formula 1.

[0147] The film-forming additive may be included in an amount of 0.004 wt% or more, 0.01 wt% or more, 0.03 wt% or more, 0.05 wt% or more, 0.07 wt% or more, 0.09 wt% or more, or 0.1 wt% or more, based on the total weight of the anode composite layer. Additionally, the film-forming additive may be included in an amount of 10 wt% or less, 9.0 wt% or less, 8.0 wt% or less, 7.0 wt% or less, 6.0 wt% or less, or 5.0 wt% or less, based on the total weight of the anode composite layer. When the content of the film-forming additive satisfies the above range, the film-forming additive prevents side reactions and forms a solid film on the surface of the anode, thereby suppressing the oxidative decomposition reaction between the anode and the electrolyte, reducing gas generation, and suppressing oxygen desorption from the anode. The above numerical ranges can be combined without limitation and, specifically, may be included in amounts of 0.004 wt% to 10 wt%, 0.01 wt% to 8 wt%, 0.1 wt% to 8 wt%, or 0.1 wt% to 5.0 wt%. That is, if the content of the film-forming additive is 0.004 wt% or more, a solid film can be formed on the surface of the positive electrode during the battery operating time, and if it is 10 wt% or less, side reactions caused by the film-forming additive can be prevented, and a thick film formed on the surface of the positive electrode can be prevented from causing an increase in resistance.

[0148] The description of other positive electrode active materials and film-forming additives is omitted as it overlaps with the aforementioned content.

[0149] In addition, the anode composite layer may optionally further include a binder, a conductive material, and / or a thickener together with the anode active material and the film-forming additive.

[0150] When the above binder is included in the above anode composite layer, the binder may be included in the above anode composite layer in an amount of 0.1% to 15% by weight, specifically 0.1% to 10% by weight.

[0151] When the conductive material is included in the anode composite layer, the conductive material may be included in the anode composite layer in an amount of 0.1% to 10.0% by weight, preferably 0.1% to 8.0% by weight.

[0152] When the above-mentioned thickener is included in the above-mentioned anode composite layer, the above-mentioned thickener may be included in the above-mentioned anode composite layer in an amount of 0.5% to 5% by weight.

[0153] Furthermore, the descriptions of the above-mentioned binder, conductive material, and thickener are omitted as they overlap with the previously mentioned contents.

[0154] Meanwhile, the thickness of the anode composite layer may be 50㎛ to 500㎛, specifically 100㎛ to 300㎛.

[0155]

[0156] Specifically, the anode of the present invention may include a urea-containing film disposed on a portion of the surface or the entire surface of the anode composite layer. Specifically, during the formation process, as the compound represented by Formula 1, which is a film-forming additive, decomposes, a urea-containing film with enhanced Li-ion characteristics can be formed on the anode surface through a ring-opening reaction caused by an oxidation reaction. In particular, the urea component contained in the compound represented by Formula 1 can suppress the anode degradation reaction or form a robust polymeric film, thereby preventing film degradation and ensuring high thermal safety of the anode surface, which can achieve an effect of improving high-temperature life characteristics and resistance increase rate.

[0157]

[0158] Meanwhile, the anode may further include an anode current collector. Specifically, the anode composite layer may be disposed on at least one surface of the anode current collector, specifically on one surface or both surfaces.

[0159] Meanwhile, the above positive current collector is not particularly limited as long as it is conductive without causing chemical changes in the battery, and for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface treated with carbon, nickel, titanium, silver, etc. may be used.

[0160] In addition, the thickness of the positive current collector is not specifically limited and can be set within an appropriate range considering the mechanical strength, productivity, or capacity of the positive ore. For example, the thickness of the positive current collector can typically be 3 μm to 500 μm. Furthermore, the positive current collector may form fine irregularities on the surface of the current collector to increase the adhesion of the positive material. For example, it can be used in various forms such as films, sheets, foils, nets, porous materials, foams, and nonwoven materials.

[0161]

[0162] Meanwhile, the anode of the present invention may be manufactured according to an anode manufacturing method known in the art. For example, the anode of the present invention may be manufactured by an anode manufacturing method comprising the steps of: preparing an anode slurry composition and then applying the anode slurry composition onto an anode current collector; and drying the anode slurry composition and then rolling it to form an anode composite layer. Alternatively, the anode of the present invention may be manufactured through an anode manufacturing method such as the step of casting the anode slurry composition onto a separate support; and laminating the anode composite layer film obtained by peeling off the support onto an anode current collector.

[0163] Specifically, in the present invention

[0164] A step of coating an anode slurry composition on an anode current collector; and

[0165] The method includes the step of forming an anode composite layer by drying and then rolling the anode slurry composition;

[0166] The above anode slurry composition provides a method for manufacturing an anode for a secondary battery, which is the anode slurry composition of the present invention.

[0167] According to the above method for manufacturing a positive electrode for a secondary battery, since a film-forming additive is introduced into the positive electrode slurry composition during the step of manufacturing the positive electrode composite layer, a smoother formation of the positive electrode film is possible compared to the case where the film-forming additive is added to a non-aqueous electrolyte and introduced into the positive electrode. Therefore, the positive electrode and secondary battery manufactured through the above method for manufacturing the positive electrode can have excellent high-temperature cycle life performance and high-temperature storage performance.

[0168] The above drying temperature may be 80 to 250 ℃.

[0169]

[0170] lithium secondary battery

[0171] A lithium secondary battery according to the present invention may include a positive electrode of the present invention, a negative electrode facing the positive electrode, and an electrolyte.

[0172] In addition, the lithium secondary battery of the present invention may further include a separator interposed between the positive electrode and the negative electrode as needed.

[0173] Meanwhile, since the description regarding the constituent materials and manufacturing method of the anode of the present invention overlaps with the above-mentioned content, such description is omitted, and other components are described below.

[0174]

[0175] (1) Cathode

[0176] The negative electrode used in the lithium secondary battery of the present invention may include a negative electrode composite layer comprising a negative electrode active material and a conductive material.

[0177] The above-mentioned negative electrode active material may include at least one selected from the group consisting of lithium metal, a carbon material capable of reversibly intercalating / deintercalating lithium ions, a metal or an alloy of these metals and lithium, a metal composite oxide, a material capable of doping and dedoping lithium, and a transition metal oxide.

[0178] As for the carbon material capable of reversibly intercalating / deintercalating the above lithium ions, any carbon-based negative electrode active material commonly used in lithium-ion secondary batteries may be used without particular limitation, and representative examples include crystalline carbon, amorphous carbon, or a combination thereof. Examples of the above crystalline carbon include graphite such as amorphous, plate-like, flake-like, spherical, or fibrous natural graphite or artificial graphite, and examples of the above amorphous carbon include soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0179] As the above metal or alloy of these metals and lithium, a metal selected from the group consisting of Cu, Ni, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn, or an alloy of these metals and lithium may be used.

[0180] The above metal composite oxides include PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5, Li x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1) and Sn x Me 1-x Me y O z(Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Group 1, 2, and 3 elements of the periodic table, halogens; 0 <x≤1; 1≤y≤3; 1≤z≤8) 로 이루어진 군에서 선택되는 것이 사용될 수 있다.

[0181] Materials capable of doping and dedoping the above lithium include Si, SiC, and SiO x (0 <x<2), Si-Y 합금(상기 Y는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Si은 아님), Sn, SnO2, Sn-Y(상기 Y는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Sn은 아님) 등을 들 수 있고, 또한 이들 중 적어도 하나와 SiO2를 혼합하여 사용할 수도 있다. 상기 원소 Y로는 Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ge, P, As, Sb, Bi, S, Se, Te, Po 및 이들의 조합으로 이루어진 군에서 선택될 수 있다.

[0182] Examples of the above transition metal oxides include lithium-containing titanium composite oxide (LTO), vanadium oxide, and lithium vanadium oxide.

[0183] According to one embodiment, the negative electrode active material of the present invention may include a carbon-based negative electrode active material or a silicon-based negative electrode active material together with the carbon-based negative electrode active material.

[0184] The above-mentioned negative electrode active material may be included in an amount of 80% to 98% by weight based on the total weight of the negative electrode composite layer. When the content of the negative electrode active material satisfies the above range, excellent capacitance characteristics and electrochemical characteristics can be obtained.

[0185] The above conductive material is used to impart conductivity to the electrode, and in the battery being constructed, it may be used without special restrictions as long as it has electronic conductivity without causing chemical changes, and may be the same as or different from the conductive material included in the positive electrode.

[0186] The above conductive material may be carbon black such as acetylene black (or Denka black), Ketjen black, channel black, furnace black, lamp black, or thermal black; graphite powder such as natural graphite, artificial graphite, or graphite with a highly developed crystal structure; conductive fibers such as carbon fibers or metal fibers; conductive powders such as carbon fluoride powder, aluminum powder, or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; polyphenylene derivatives, etc., and one of these alone or a mixture of two or more may be used.

[0187] The conductive material may be included in the cathode composite layer in an amount of about 0.01 to 2.0 weight%, specifically 0.01 to 1.5 weight%, and more specifically 0.01 to 1.0 weight% based on the total weight of the cathode composite layer. If the content of the conductive material is 0.01 weight% or more, sufficient conductivity between active materials can be secured, and if the content of the conductive material is 2.0 weight% or less, the content of the cathode active material included in the cathode composite layer can be increased, thereby enabling the manufacture of a lithium secondary battery capable of securing excellent high capacity.

[0188]

[0189] The above cathode composite layer may further include a binder.

[0190] The above binder is a component that assists in the bonding between a conductive material, an active material, or a current collector, and examples of such binders include fluoropolymer-based binders comprising polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); rubber-based binders comprising styrene butadiene rubber (SBR), acrylonitrile-butadiene rubber, or styrene-isoprene rubber; cellulose-based binders comprising carboxyl methyl cellulose (CMC), starch, hydroxypropyl cellulose, or regenerated cellulose; polyalcohol-based binders comprising polyvinyl alcohol; polyolefin-based binders comprising polyethylene or polypropylene; polyimide-based binders; polyester-based binders; and silane-based binders.

[0191] The binder may be included in the cathode composite layer in an amount of 0.1 to 15.0 weight%, preferably 0.1 to 10.0 weight%, based on the total weight of the cathode composite layer.

[0192]

[0193] The above cathode may further include a cathode current collector. Specifically, the cathode composite layer may be disposed on the cathode current collector.

[0194] The above-mentioned negative current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., and aluminum-cadmium alloy may be used. In addition, the above-mentioned negative current collector may typically have a thickness of 3 μm to 500 μm, and, similar to the positive current collector, fine irregularities may be formed on the surface of the current collector to strengthen the bonding strength of the negative active material. For example, it may be used in various forms such as a film, sheet, foil, net, porous body, foam, nonwoven fabric, etc.

[0195]

[0196] Meanwhile, the above-mentioned cathode may be manufactured according to a cathode manufacturing method known in the art. For example, the above-mentioned cathode may be manufactured by forming a cathode composite layer by applying a cathode slurry, prepared by dissolving or dispersing a carbon-based active material, a cathode conductive material, and optionally a binder in a solvent, onto a cathode current collector, rolling, and drying, or by casting the cathode slurry onto a support and then peeling off the support to obtain a cathode composite layer, and then laminating the resulting film onto a cathode current collector.

[0197] The above solvent may be a solvent commonly used in the relevant technical field, and may include dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, or water, and one of these alone or a mixture of two or more may be used. The amount of the above solvent used is not particularly limited, provided that it is sufficient to adjust the cathode slurry to have an appropriate viscosity, taking into account the coating thickness of the cathode composite material, manufacturing yield, workability, etc.

[0198]

[0199] (2) Electrolyte

[0200] The electrolyte included in the lithium secondary battery according to the present invention may be a gel electrolyte, a solid electrolyte, or a non-aqueous electrolyte. Specifically, the non-aqueous electrolyte may include a lithium salt, a non-aqueous organic solvent, and an additive.

[0201] (2-1) Lithium salt

[0202] First, the above lithium salt can be any that are commonly used in electrolytes for lithium secondary batteries without limitation, for example, Li as a cation + It includes, and as anion, F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , B 10 Cl 10 - , AlCl4 - , AlO4 - , PF6 - , CF3SO3 - , CH3CO2 - , CF3CO2 - , AsF6 - , SbF6 - , CH3SO3 - , (CF3CF2SO2)2N - , (CF3SO2)2N - , (FSO2)2N - , BF2C2O4 - , BC4O8 - , PF4C2O4 - , PF2C4O8 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , C4F9SO3 - , CF3CF2SO3 -, CF3CF2(CF3)2CO - , (CF3SO2)2CH - and CF3(CF2)7SO3 - It may include at least one selected from the group consisting of

[0203] Specifically, the lithium salt is LiCl, LiBr, LiI, LiBF4, LiClO4, LiB 10 Cl 10 It may include a single substance or a mixture of two or more substances selected from the group consisting of LiAlCl4, LiAlO4, LiPF6, LiCF3SO3, LiCH3CO2, LiCF3CO2, LiAsF6, LiSbF6, LiCH3SO3, LiN(SO2F)2(Lithium bis(fluorosulfonyl)imide, LiFSI), LiN(SO2CF2CF3)2(lithium bis(pentafluoroethanesulfonyl)imide, LiBETI), and LiN(SO2CF3)2(lithium bis(trifluoromethanesulfonyl)imide, LiTFSI), and specifically LiBF4, LiPF6, LiN(SO2F)2(Lithium bis(fluorosulfonyl)imide, LiFSI), LiN(SO2CF2CF3)2(lithium bis(pentafluoroethanesulfonyl)imide, LiBETI), and LiN(SO2CF3)2(lithium It may include at least one selected from the group consisting of bis(trifluoromethanesulfonyl)imide (LiTFSI). In addition to these, lithium salts commonly used in the electrolytes of lithium secondary batteries may be used without limitation.

[0204] The above lithium salt can be appropriately modified within a range that is typically usable, but in order to obtain the effect of forming a corrosion-preventing film on the optimal electrode surface, it may be included in the electrolyte at a concentration of 0.8M to 3.0M, specifically 1.0M to 2.0M, preferably 1.0M to 1.8M.

[0205] When the concentration of the lithium salt is within the above range, the viscosity of the non-aqueous electrolyte can be controlled to achieve optimal impregnation, and the mobility of lithium ions can be improved to obtain the effect of improving the capacity characteristics and cycle characteristics of the lithium secondary battery.

[0206]

[0207] (2-2) Non-aqueous organic solvents

[0208] In addition, the description of the above-mentioned non-aqueous organic solvent is as follows.

[0209] As the above-mentioned non-aqueous organic solvent, various organic solvents commonly used in non-aqueous electrolytes may be used without limitation. There are no restrictions on the type of solvent provided that decomposition due to oxidation reactions, etc., during the charging and discharging process of the secondary battery can be minimized and that it can exhibit the desired characteristics in combination with additives.

[0210] Specifically, the above-mentioned non-aqueous organic solvent may include at least one of a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent in order to secure high ionic conductivity.

[0211] The above-mentioned cyclic carbonate-based organic solvent is a high-viscosity organic solvent that has a high dielectric constant and effectively dissociates lithium salts in a non-aqueous electrolyte. Specific examples thereof may include at least one organic solvent selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, and vinylene carbonate, and among these, at least one of ethylene carbonate (EC) and propylene carbonate (PC) may be included.

[0212] The above linear carbonate-based organic solvent is an organic solvent having low viscosity and low dielectric constant, and as specific examples, it may include at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethylmethyl carbonate (EMC), methylpropyl carbonate, and ethylpropyl carbonate, and specifically, it may include at least one of dimethyl carbonate, ethylmethyl carbonate, and diethyl carbonate.

[0213] In order to secure high ion conductivity in the present invention, a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent may be mixed and used as the non-aqueous organic solvent, and the cyclic carbonate-based organic solvent and the linear carbonate-based organic solvent may be mixed and used in a volume ratio of 10:90 to 50:50, a volume ratio of 10:90 to 40:60, or a volume ratio of 20:80 to 40:60.

[0214] If necessary, the above-mentioned non-aqueous organic solvent may additionally include a linear ester-based organic solvent that has a lower melting point than the cyclic carbonate-based organic solvent and high stability at high temperatures.

[0215] Specific examples of the above linear ester-based organic solvent may include at least one organic solvent selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate, and preferably, it may be at least one of ethyl propionate and propyl propionate.

[0216] Meanwhile, the remainder of the non-aqueous electrolyte of the present invention, excluding the lithium salt and additives, may all include a non-aqueous organic solvent unless otherwise noted.

[0217]

[0218] (2-3) Additives

[0219] Next, the non-aqueous electrolyte of the present invention may include additives to form a robust film on the surface of the cathode so that the non-aqueous electrolyte decomposes in a high-power environment, thereby inducing cathode collapse, while simultaneously improving low-temperature high-rate discharge characteristics, high-temperature stability, prevention of overcharging, and suppression of battery expansion at high temperatures.

[0220] The above additive may further include, as specific examples, at least one selected from the group consisting of cyclic carbonate compounds, fluorine-based cyclic carbonate compounds, sulfone compounds, sulfate compounds, phosphate compounds, nitrile compounds, benzene compounds, amine compounds, and silane compounds.

[0221] Examples of the above-mentioned cyclic carbonate compounds include vinylene carbonate (VC) or vinylethylene carbonate. The above-mentioned cyclic carbonate compounds may be included in an amount of 1.0% to 10% by weight, specifically 1.0% to 5.0% by weight, of the total weight of the non-aqueous electrolyte. When the content of the above-mentioned cyclic carbonate compounds satisfies the above range, low-temperature output of the battery and high-temperature storage characteristics and high-temperature life characteristics can be effectively improved while suppressing side reactions.

[0222] In addition, the above-mentioned fluorine-based cyclic carbonate compound may include fluoroethylene carbonate (FEC). The above-mentioned fluoroethylene carbonate (FEC) forms a robust film containing polymer components on the surface of the cathode, thereby minimizing damage to the SEI film during high-voltage charging and discharging, and preventing cathode degradation. The above-mentioned fluorine-based cyclic carbonate compound may be included in an amount of 500 to 1,000 parts by weight based on 100 parts by weight of the total content of lithium difluorophosphate (LiDFP) and hexamethylene diisocyanate. When the content of the above-mentioned fluorine-based cyclic carbonate compound satisfies the above range, it is possible to effectively prevent the degradation of the anode and cathode during high-voltage charging and high-temperature storage by forming a robust film on the surfaces of the anode and cathode while preventing side reactions caused by additives that remain undecomposed.

[0223] In addition, the sulfone-based compound may include at least one compound selected from the group consisting of 1,3-propane sulfone (PS), 1,4-butane sulfone, ethene sulfone, 1,3-propene sulfone (PRS), 1,4-butene sulfone, and 1-methyl-1,3-propene sulfone, and preferably may include 1,3-propane sulfone (PS). The sulfone-based compound forms a stable SEI film by a reduction reaction on the cathode surface, thereby preventing side reactions between the cathode and the electrolyte at high temperatures, suppressing gas generation, and enabling increased durability during high-temperature storage. Such a sulfone-based compound may be included in an amount of 1.0% to 10% by weight, specifically 1.0% to 5.0% by weight, of the total weight of the non-aqueous electrolyte. When the content of the sulfone-based compound satisfies the above range, a robust film is formed on the surfaces of the anode and cathode, which can effectively prevent deterioration of the anode and cathode during high-voltage charging and high-temperature storage.

[0224] In addition, the above sulfate-based compound may be ethylene sulfate (Esa), trimethylene sulfate (TMS), or methyl trimethylene sulfate (MTMS). The above sulfate-based compound may be included in an amount of 0.01 to 10 weight%, specifically 0.05 to 5.0 weight%, of the total weight of the non-aqueous electrolyte. If the content of the above sulfate-based compound satisfies the above range, side reactions within the electrolyte during charging and discharging of the battery are suppressed, and a robust SEI film is formed, thereby achieving an effect of improving excellent lifespan characteristics.

[0225] The above phosphate-based compound may be one or more compounds selected from the group consisting of lithium difluoro(bisoxalato)phosphate, lithium difluorophosphate (LiDFP), tris(trimethylsilyl)phosphate, tris(2,2,2-trifluoroethyl)phosphate, and tris(trifluoroethyl)phosphate. The above phosphate-based compound may be included in an amount of 0.01 to 10 weight%, specifically 0.05 to 5.0 weight%, based on the total weight of the non-aqueous electrolyte. When the content of the above phosphate-based compound satisfies the above range, a robust SEI film is formed, thereby achieving the effect of improving low-temperature output, high-temperature storage characteristics, and high-temperature life characteristics of the battery.

[0226] In addition, the nitrile-based compound may include at least one compound selected from the group consisting of succinonitrile, hexane tricyanide (HTCN), adiponitrile, acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanitrile, hexamethylene diisocyanate, 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile.

[0227] The above nitrile-based compound may be included in an amount of 1.0% to 10% by weight, specifically 1.0% to 5.0% by weight, of the total weight of the non-aqueous electrolyte. When the content of the above nitrile-based compound satisfies the above range, a stable film is formed on the surfaces of the cathode and anode to suppress gas generation caused by side reactions between the anode and the electrolyte, and the leaching of metal foreign matter can be effectively suppressed.

[0228] Examples of the above benzene-based compound include fluorobenzene. The above benzene-based compound may be included in an amount of 0.01 to 10 weight%, specifically 0.05 to 5.0 weight%, based on the total weight of the non-aqueous electrolyte.

[0229] Examples of the above amine-based compounds include triethanolamine or ethylenediamine. The above amine-based compounds may be included in an amount of 0.01 to 10 weight%, specifically 0.05 to 5.0 weight%, based on the total weight of the non-aqueous electrolyte.

[0230] Tetravinylsilane may be an example of the above silane compound. The above silane compound may be included in an amount of 0.01 to 10 weight%, specifically 0.05 to 5.0 weight%, based on the total weight of the non-aqueous electrolyte.

[0231]

[0232] (3) Separator

[0233] The above separator separates the negative and positive electrodes and provides a pathway for the movement of lithium ions. It can be used without any particular restrictions as long as it is typically used as a separator in a lithium secondary battery, and it is particularly desirable that it has low resistance to the movement of lithium salt ions while having excellent electrolyte moisture retention capacity.

[0234] Specifically, as a separator, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof may be used. In addition, a conventional porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fibers or polyethylene terephthalate fibers, may be used. Furthermore, a coated separator containing a ceramic component or a polymer material may be used to ensure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure.

[0235]

[0236] The lithium secondary battery according to the present invention as described above can be usefully applied in portable devices such as mobile phones, laptop computers, and digital cameras, as well as in the field of electric vehicles such as hybrid electric vehicles (HEVs).

[0237] The external shape of the lithium secondary battery of the present invention is not particularly limited, but can be a cylindrical shape using a can, a prismatic shape, a pouch shape, or a coin shape.

[0238] The lithium secondary battery according to the present invention can be used not only as a battery cell used as a power source for a small device, but can also preferably be used as a unit cell in a medium-to-large battery module comprising a plurality of battery cells.

[0239]

[0240] Hereinafter, the present invention will be described in detail with reference to examples in order to specifically explain the invention. However, the embodiments according to the present invention may be modified in various different forms, and the scope of the present invention should not be interpreted as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the invention to those with average knowledge in the art.

[0241]

[0242] [Example]

[0243] Example 1.

[0244] (Preparation of anode slurry composition)

[0245] N-methylpyrrolidone (NMP) with a positive active material (Li(Ni) 0.6 Mn 0.3 Co 0.1 An anode slurry composition was prepared by dissolving a conductive material (carbon nanotube), a binder (PVDF), and a thickener (CMC) in a weight ratio of 97.00:1.20:1.44:0.36, and then adding a compound represented by Chemical Formula 1A as a film-forming additive to make up 0.4% by weight based on the total solid content.

[0246]

[0247] (Anode manufacturing)

[0248] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0249]

[0250] (Cathode manufacturing)

[0251] In distilled water, a cathode active material (graphite and SiC = 95:5 weight ratio), a binder (SBR), and bundled single-walled carbon nanotubes (SWCNT) with an average diameter of 10 nm (length: 7 µm, specific surface area: 1,000 m²) as a conductive material 2A negative electrode active material slurry was prepared by adding (manufacturer: Nano Materials) in a weight ratio of 96.84:3.15:0.01. The negative electrode active material slurry prepared above was coated onto a copper current collector with a thickness of 15 μm, and then dried and rolled to produce a negative electrode.

[0252]

[0253] (Preparation of non-aqueous electrolytes)

[0254] A non-aqueous electrolyte was prepared by dissolving LiPF6 to a concentration of 1.2 M in a non-aqueous organic solvent mixed with ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 2:7:1, and then adding vinylene carbonate to a concentration of 0.5 wt%.

[0255]

[0256] (Secondary battery manufacturing)

[0257] An electrode assembly was manufactured by interposing a porous separator (polypropylene) between the anode and the cathode opposite to the anode, then housing it in a battery case, and then injecting the manufactured non-aqueous electrolyte to manufacture a lithium secondary battery.

[0258]

[0259] Example 2.

[0260] (Preparation of anode slurry composition)

[0261] An anode slurry composition was prepared in the same manner as in Example 1, except that a compound represented by Chemical Formula 1B was included instead of a compound represented by Chemical Formula 1A as a film-forming additive.

[0262]

[0263] (Anode manufacturing)

[0264] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0265]

[0266] (Secondary battery manufacturing)

[0267] A lithium secondary battery was manufactured in the same manner as Example 1, except that it includes the positive electrode manufactured above.

[0268]

[0269] Example 3.

[0270] (Preparation of anode slurry composition)

[0271] An anode slurry composition was prepared in the same manner as in Example 1, except that a compound represented by Chemical Formula 1C was included instead of a compound represented by Chemical Formula 1A as a film-forming additive.

[0272]

[0273] (Anode manufacturing)

[0274] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0275]

[0276] (Secondary battery manufacturing)

[0277] A lithium secondary battery was manufactured in the same manner as Example 1, except that it includes the positive electrode manufactured above.

[0278]

[0279] Example 4.

[0280] (Preparation of anode slurry composition)

[0281] An anode slurry composition was prepared in the same manner as in Example 1, except that a compound represented by Chemical Formula 1D was included instead of a compound represented by Chemical Formula 1A as a film-forming additive.

[0282]

[0283] (Anode manufacturing)

[0284] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0285]

[0286] (Secondary battery manufacturing)

[0287] A lithium secondary battery was manufactured in the same manner as Example 1, except that it includes the positive electrode manufactured above.

[0288]

[0289] Example 5.

[0290] (Preparation of anode slurry composition)

[0291] An anode slurry composition was prepared in the same manner as in Example 1, except that a compound represented by Chemical Formula 1E was included instead of a compound represented by Chemical Formula 1A as a film-forming additive.

[0292]

[0293] (Anode manufacturing)

[0294] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0295]

[0296] (Secondary battery manufacturing)

[0297] A lithium secondary battery was manufactured in the same manner as Example 1, except that it includes the positive electrode manufactured above.

[0298]

[0299] Example 6.

[0300] (Preparation of anode slurry composition)

[0301] An anode slurry composition was prepared in the same manner as in Example 1, except that a compound represented by Chemical Formula 1F was included instead of a compound represented by Chemical Formula 1A as a film-forming additive.

[0302]

[0303] (Anode manufacturing)

[0304] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0305]

[0306] (Secondary battery manufacturing)

[0307] A lithium secondary battery was manufactured in the same manner as Example 1, except that it includes the positive electrode manufactured above.

[0308]

[0309] Example 7.

[0310] (Preparation of anode slurry composition)

[0311] An anode slurry composition was prepared in the same manner as in Example 1, except that a compound represented by chemical formula 1G was included instead of a compound represented by chemical formula 1A as a film-forming additive.

[0312]

[0313] (Anode manufacturing)

[0314] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0315]

[0316] (Secondary battery manufacturing)

[0317] A lithium secondary battery was manufactured in the same manner as Example 1, except that it includes the positive electrode manufactured above.

[0318]

[0319] Example 8.

[0320] (Preparation of anode slurry composition)

[0321] N-methylpyrrolidone (NMP) with a positive active material (Li(Ni) 0.6 Mn 0.3 Co 0.1 An anode slurry composition was prepared by dissolving a conductive material (carbon nanotube), a binder (PVDF), and a thickener (CMC) in a weight ratio of 97.00:1.20:1.44:0.36, and then adding a compound represented by Chemical Formula 1A as a film-forming additive to make up 10.0 wt% of the total solid content.

[0322]

[0323] (Anode manufacturing)

[0324] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0325]

[0326] (Secondary battery manufacturing)

[0327] A lithium secondary battery was manufactured in the same manner as in Example 1, except that the anode manufactured above was used.

[0328]

[0329] Example 9.

[0330] (Preparation of anode slurry composition)

[0331] N-methylpyrrolidone (NMP) with a positive active material (Li(Ni) 0.6 Mn 0.3 Co 0.1An anode slurry composition was prepared by dissolving a conductive material (carbon nanotube), a binder (PVDF), and a thickener (CMC) in a weight ratio of 97.00:1.20:1.44:0.36, and then adding a compound represented by Chemical Formula 1A as a film-forming additive to make up 1.0 wt% based on the total solid content.

[0332]

[0333] (Anode manufacturing)

[0334] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0335]

[0336] (Secondary battery manufacturing)

[0337] A lithium secondary battery was manufactured in the same manner as in Example 1, except that the anode manufactured above was used.

[0338]

[0339] Example 10.

[0340] (Preparation of anode slurry composition)

[0341] N-methylpyrrolidone (NMP) with a positive active material (Li(Ni) 0.6 Mn 0.3 Co 0.1 An anode slurry composition was prepared by dissolving a conductive material (carbon nanotube), a binder (PVDF), and a thickener (CMC) in a weight ratio of 97.00:1.20:1.44:0.36, and then adding a compound represented by Chemical Formula 1A as a film-forming additive to make up 5.0 wt% of the total solid content.

[0342]

[0343] (Anode manufacturing)

[0344] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0345]

[0346] (Secondary battery manufacturing)

[0347] A lithium secondary battery was manufactured in the same manner as in Example 1, except that the anode manufactured above was used.

[0348]

[0349] Example 11.

[0350] (Preparation of anode slurry composition)

[0351] N-methylpyrrolidone (NMP) with a positive active material (Li(Ni) 0.6 Mn 0.3 Co 0.1 An anode slurry composition was prepared by dissolving a conductive material (carbon nanotube), a binder (PVDF), and a thickener (CMC) in a weight ratio of 97.0:1.20:1.44:0.36, and then adding a compound represented by Chemical Formula 1A as a film-forming additive to make up 8.0 wt% of the total solid content.

[0352]

[0353] (Anode manufacturing)

[0354] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0355]

[0356] (Secondary battery manufacturing)

[0357] A lithium secondary battery was manufactured in the same manner as in Example 1, except that the anode manufactured above was used.

[0358]

[0359] Comparative Example 1.

[0360] (Preparation of anode slurry composition)

[0361] N-methylpyrrolidone (NMP) with a positive active material (Li(Ni) 0.6 Mn 0.3 Co 0.1 An anode slurry composition was prepared by dissolving )O2), a conductive material (carbon nanotube), a binder (PVDF), and a thickener (CMC) in a weight ratio of 97.00:1.20:1.44:0.36.

[0362]

[0363] (Anode manufacturing)

[0364] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0365]

[0366] (Cathode manufacturing)

[0367] In distilled water, a cathode active material (graphite and SiC = 95:5 weight ratio), a binder (SBR), and bundled single-walled carbon nanotubes (SWCNT) with an average diameter of 10 nm (length: 7 µm, specific surface area: 1,000 m²) as a conductive material 2 A negative electrode active material slurry was prepared by adding 96.84:3.15:0.01 parts by weight of ( / g, Manufacturer: Nano Materials). The negative electrode active material slurry prepared above was coated onto a copper current collector with a thickness of 15 μm, and then dried and rolled to produce a negative electrode.

[0368]

[0369] (Preparation of non-aqueous electrolytes)

[0370] A non-aqueous electrolyte was prepared by dissolving LiPF6 to a concentration of 1.2 M in a non-aqueous solvent mixed with ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 2:7:1, and then adding vinylene carbonate to a concentration of 0.5 wt%.

[0371]

[0372] (Secondary battery manufacturing)

[0373] An electrode assembly was manufactured by interposing a porous separator polypropylene between the anode and the manufactured cathode, then housing it in a battery case, and a lithium secondary battery was manufactured by injecting the manufactured non-aqueous electrolyte.

[0374]

[0375] Comparative Example 2.

[0376] (Preparation of non-aqueous electrolytes)

[0377] A non-aqueous electrolyte was prepared by dissolving LiPF6 to a concentration of 1.2 M in a non-aqueous solvent mixed with ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 2:7:1, and then adding 1.0 wt% of a compound represented by Chemical Formula 1A and 0.5 wt% of vinylene carbonate.

[0378]

[0379] (Secondary battery manufacturing)

[0380] A lithium secondary battery was manufactured in the same manner as Comparative Example 1, except that the above-mentioned non-aqueous electrolyte was injected.

[0381]

[0382] Comparative Example 3.

[0383] (Preparation of anode slurry composition)

[0384] An anode slurry composition was prepared in the same manner as in Example 1 above, except that a compound represented by the following chemical formula 3A was included instead of a compound represented by chemical formula 1A as a film-forming additive.

[0385] [Chemical Formula 3A]

[0386]

[0387]

[0388] (Anode manufacturing)

[0389] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0390]

[0391] (Secondary battery manufacturing)

[0392] A lithium secondary battery was manufactured in the same manner as Comparative Example 1, except that the anode manufactured above was used.

[0393]

[0394] Comparative Example 4.

[0395] (Preparation of anode slurry composition)

[0396] An anode slurry composition was prepared in the same manner as in Example 1 above, except that a compound represented by the following chemical formula 3B was included instead of a compound represented by chemical formula 1A as a film-forming additive.

[0397] [Chemical Formula 3B]

[0398]

[0399]

[0400] (Anode manufacturing)

[0401] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0402]

[0403] (Secondary battery manufacturing)

[0404] A lithium secondary battery was manufactured in the same manner as Comparative Example 1, except that the anode manufactured above was used.

[0405]

[0406] Comparative Example 5.

[0407] (Preparation of anode slurry composition)

[0408] An anode slurry composition was prepared in the same manner as in Example 1 above, except that a compound represented by the following chemical formula 3C was included instead of a compound represented by chemical formula 1A as a film-forming additive.

[0409] [Chemical Formula 3C]

[0410]

[0411]

[0412] (Anode manufacturing)

[0413] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0414]

[0415] (Secondary battery manufacturing)

[0416] A lithium secondary battery was manufactured in the same manner as Comparative Example 1, except that the anode manufactured above was used.

[0417]

[0418] Comparative Example 6.

[0419] (Preparation of anode slurry composition)

[0420] An anode slurry composition was prepared in the same manner as in Example 1 above, except that a compound represented by the following chemical formula 3D was included instead of a compound represented by chemical formula 1A as a film-forming additive.

[0421] [Chemical Formula 3D]

[0422]

[0423]

[0424] (Anode manufacturing)

[0425] The anode slurry composition prepared above was applied to an aluminum foil (Al foil) current collector with a thickness of 12 μm, and then dried and rolled at 50°C for 2 hours to produce an anode with an anode composite layer formed thereon.

[0426]

[0427] (Secondary battery manufacturing)

[0428] A lithium secondary battery was manufactured in the same manner as Comparative Example 1, except that the anode manufactured above was used.

[0429]

[0430] Experimental Example

[0431] Experimental Example 1. Evaluation of High-Temperature Cycle Characteristics

[0432] The lithium secondary batteries prepared in Examples 1 to 11 and the lithium secondary batteries prepared in Comparative Examples 1 to 6 were each charged to 4.5V at a constant current / constant voltage condition at a rate of 0.33 C at room temperature (25℃), discharged for 10 seconds at a rate of 0.33 C, and then the initial capacity was measured using a PNE-0506 charge / discharger (manufacturer: PNE solution).

[0433] Then, 200 cycles were performed, with one cycle consisting of charging to 4.5 V under constant current / constant voltage conditions at a rate of 0.33 C at a high temperature (45℃) and discharging to 2.5 V under constant current conditions at a rate of 0.33 C. Afterward, the capacity retention rate, resistance increase rate, and gas generation amount were measured, and the results are shown in Table 1 below.

[0434] Capacity retention rate (%) after 200 cycles Resistance increase rate (%) Gas generation amount (μL) Example 1: 9318983 Example 2: 90201032 Example 3: 92201342 Example 4: 89171100 Example 5: 87241499 Example 6: 68241320 Example 7: 88261230 Example 8: 84251653 Example 9: 90191076 Example 10: 88271260 Example 11: 86241311 Comparative Example 1: 65423213 Comparative Example 2: 79311975 Comparative Example 3: 78292215 Comparative Example 4: 80322013 Comparative Example 5: 77312316 Comparative Example 6: 680292152

[0435]

[0436] Referring to Table 1 above, it can be seen that in the case of the lithium secondary batteries manufactured in Examples 1 to 11 of the present invention, the capacity retention rate (%) after high-temperature cycling, the resistance increase rate, and the amount of gas generated are mostly significantly improved compared to the lithium secondary batteries of Comparative Examples 1 to 6.

[0437]

[0438] Experimental Example 2. Evaluation of High-Temperature Storage Characteristics

[0439] The lithium secondary batteries prepared in Examples 1 to 11 and the lithium secondary batteries prepared in Comparative Examples 1 to 6 were each charged to a high voltage of 4.5V at a constant current / constant voltage condition at a rate of 0.33 C at room temperature (25℃), discharged for 10 seconds at a rate of 0.33 C, and then the initial capacity was measured using a PNE-0506 charge / discharger (manufacturer: PNE solution).

[0440] Then, after storing at a high temperature (60℃) for 8 weeks, one cycle was performed in which the device was charged to 4.5V under constant current / constant voltage conditions at a rate of 0.33 C and discharged to 2.5V under constant current conditions at a rate of 0.33 C, and then the capacity retention rate, resistance increase rate, and gas generation amount were measured, and the results are shown in Table 2 below.

[0441] Capacity retention rate (%) after high temperature (60℃) storage Resistance increase rate (%) Gas generation amount (µL) Example 19 219 1213 Example 28 9 2114 02 Example 38 9 2313 20 Example 49 0 2214 52 Example 58 8 2315 23 Example 68 6 2518 22 Example 78 6 2416 51 Example 88 5 2719 30 Example 99 0 19 14 02 Example 108 8 2416 50 Example 118 6 2716 54 Comparative Example 16 245 5215 Comparative Example 27 6 3129 20 Comparative Example 37 5 293 011 Comparative Example 47 6 26 3151 Comparative Example 57 42 93 245 Comparative Example 679302957

[0442]

[0443] Referring to Table 2 above, it can be seen that in the case of the lithium secondary batteries manufactured in Examples 1 to 11 of the present invention, the capacity retention rate (%) after high-temperature storage, the resistance increase rate, and the amount of gas generated are significantly improved compared to the lithium secondary batteries of Comparative Examples 1 to 6.

[0444]

[0445] Experimental Example 3. Hot box evaluation

[0446] The lithium secondary batteries prepared in Examples 1 to 11 and the lithium secondary battery prepared in Comparative Example 1 were each fully charged to a State of Charge (SOC) of 100%, the fully charged battery cells were stored inside a box, and the internal temperature of the box was raised from room temperature to 150°C at a rate of 2°C / min, and then stored at 150°C for 120 minutes. During storage, it was checked whether the lithium secondary batteries ignited, and the results are shown in Table 3 below. In Table 3 below, if the lithium secondary battery ignited, it was indicated as Fail, and if it did not ignite, it was indicated as Pass.

[0447] Hot box Evaluation Example 1 Pass Example 2 Pass Example 3 Pass Example 4 Pass Example 5 Pass Example 6 Pass Example 7 Pass Example 8 Pass Example 9 Pass Example 10 Pass Example 11 Pass Comparison Example 1 Fail

[0448]

[0449] Referring to Table 3 above, it can be seen that in the case of the lithium secondary batteries manufactured in Examples 1 to 11 of the present invention, ignition is not induced even when stored at high temperatures. On the other hand, it can be seen that the lithium secondary battery manufactured in Comparative Example 1 ignited when stored at high temperatures.

Claims

1. It comprises a positive electrode active material, a film-forming additive, and a solvent, and A positive electrode slurry composition for a lithium secondary battery in which the above-mentioned film-forming additive is a compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, R1 is -SO2F, -OSO2N(R a )(R b ), -SO2R c , -OLi or -OR', where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c is a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine, and R' is a carbon-1 to carbon-10 alkyl group.

2. In Paragraph 1, In the above Chemical Formula 1, R1 is -SO2F, -OSO2N(R a )(R b ) or -SO2Rc, where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c A positive electrode slurry composition for a lithium secondary battery, wherein the alkyl group having 1 to 5 carbon atoms is substituted or unsubstituted with fluorine.

3. In Paragraph 1, In the above Chemical Formula 1, R1 is -SO2F, -OSO2N(R a )(R b ) or -SO2Rc, where R a and R b are independently alkyl groups having 1 to 3 carbon atoms, and R c A positive electrode slurry composition for a lithium secondary battery, wherein the alkyl group having 1 to 3 carbon atoms is substituted or unsubstituted with fluorine.

4. In Paragraph 1, A positive electrode slurry composition for a lithium secondary battery in which the compound represented by Chemical Formula 1 above is at least one of the compounds represented by Chemical Formulas 1A to 1G below: [Chemical Formula 1A] [Chemical Formula 1B] [Chemical Formula 1C] [Chemical Formula 1D] [Chemical Formula 1E] [Chemical Formula 1F] [Chemical Formula 1G] .

5. In Paragraph 1, A positive electrode slurry composition for a lithium secondary battery, wherein the above film-forming additive is included in an amount of 0.004% to 10% by weight based on the total weight of the solid content of the above positive electrode slurry composition.

6. In Paragraph 1, A positive electrode slurry composition for a lithium secondary battery, wherein the above film-forming additive is included in an amount of 0.1% to 8.0% by weight based on the total weight of the solid content of the positive electrode slurry composition.

7. In Paragraph 1, The above-mentioned positive active material is a positive slurry composition comprising a compound represented by the following chemical formula 2: [Chemical Formula 2] Li 1+a Ni x Co y M 1 z M 2 w O2 In the above chemical formula 2, M 1 is Mn, Al, or a combination thereof, and M 2 is at least one selected from the group consisting of Al, Zr, W, Ti, Mg, Ca, and Sr, and 0≤a≤0.5, 0 <x<1.0, 0<y≤0.4, 0<z≤0.4, 0≤w≤0.1, x+y+z+w= 1이다.

8. In Paragraph 1, The above-described positive electrode slurry composition for a lithium secondary battery further comprises at least one of a conductive material, a binder, and a thickener.

9. A positive electrode composite layer comprising a positive electrode active material and a film-forming additive, and The above film-forming additive is a positive electrode for a lithium secondary battery, which is a compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, R1 is -SO2F, -OSO2N(R a )(R b ), -SO2R c , -OLi or -OR', where R a and R b are independently alkyl groups having 1 to 5 carbon atoms, and R c is a carbon-1 to carbon-5 alkyl group substituted or unsubstituted with fluorine, and R' is a carbon-1 to carbon-10 alkyl group.

10. In Paragraph 9, The above anode composite layer is an anode comprising a urea-containing film.

11. A step of applying an anode slurry composition onto an anode current collector; and The method includes the step of forming an anode composite layer by drying and then rolling the anode slurry composition; The above anode slurry composition is a method for manufacturing an anode for a secondary battery, which is the anode slurry composition for a lithium secondary battery of claim 1.

12. A lithium secondary battery comprising a positive electrode according to claim 9; a negative electrode facing the positive electrode; and an electrolyte.

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