Lithium secondary battery

Abstract

The present application provides a lithium secondary battery. In particular, the lithium secondary battery includes: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; a separator interposed between the negative electrode and the positive electrode; and a non-aqueous electrolyte solution for a lithium secondary battery, wherein the non-aqueous electrolyte solution for a lithium secondary battery includes a lithium salt, an organic solvent, and a compound represented by Formula 1. Accordingly, the overall performance of the battery can be improved.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0122325, filed on September 14, 2021, the disclosure of which is incorporated herein by reference. Technical Field

[0004] This invention relates to a lithium secondary battery, which has excellent high-temperature stability and high-temperature cycling characteristics. Background Technology

[0005] As the information society has developed personal IT devices and computer networks, and society's overall reliance on electricity has increased, there is a need to develop a technology for the efficient storage and utilization of electrical energy.

[0006] Because secondary batteries can be manufactured small enough for applications in personal IT devices, electric vehicles, and energy storage devices, they are attracting increasing attention as the most suitable technology for a wide range of applications. Among secondary batteries, lithium-ion batteries (LIBs), as battery systems with high energy density, are receiving significant attention and are currently used in various devices.

[0007] A lithium-ion battery consists of a positive electrode made of a lithium-containing transition metal oxide, a negative electrode capable of storing lithium, an electrolyte solution containing an organic solvent containing a lithium salt, and a separator.

[0008] Meanwhile, to achieve suitable battery performance, lithium-ion batteries primarily use LiPF6 as a representative lithium salt. However, because LiPF6 is highly sensitive to heat, when the battery is exposed to high temperatures, LiPF6 thermally decomposes and produces Lewis acids such as PF5. Such Lewis acid materials not only cause decomposition reactions of organic solvents such as ethylene carbonate, but also degrade the film formed on the electrode surface, such as the solid electrolyte interphase (SEI), leading to further electrolyte solution decomposition reactions and the elution of transition metals from the positive electrode.

[0009] The eluted transition metal ions are redeposited on the positive electrode, increasing its resistance. Conversely, they are transferred to the negative electrode through the electrolyte solution and then deposited there. Due to the self-discharge of the negative electrode or the destruction and regeneration of the solid electrolyte interphase (SEI) film, additional lithium ions are consumed, leading to increased resistance and deterioration of lifespan.

[0010] Therefore, in order to suppress the degradation behavior of batteries when exposed to high temperatures, there is increasing attention on methods that can remove byproducts (such as HF and PF5) generated by the thermal decomposition of lithium salts and at the same time improve the passivation capability of the SEI film. Summary of the Invention

[0011] Technical issues

[0012] One aspect of the present invention provides a lithium secondary battery that achieves excellent high-temperature stability and high-temperature cycling characteristics by including a non-aqueous electrolyte solution containing an electrolyte solution additive capable of removing decomposition products generated by lithium salts, and simultaneously achieving an enhanced SEI effect.

[0013] Technical solution

[0014] According to one aspect of the present invention, a lithium secondary battery is provided, comprising: a positive electrode comprising a positive electrode active material; a negative electrode comprising a negative electrode active material; a separator between the negative electrode and the positive electrode; and a non-aqueous electrolyte solution comprising a lithium salt, an organic solvent, and a compound represented by Formula 1.

[0015] [Formula 1]

[0016]

[0017] In Formula 1, A is a C1 to C5 alkyl group.

[0018] Beneficial effects

[0019] The non-aqueous electrolyte solution contained in the lithium secondary battery of the present invention comprises a Lewis base compound represented by Formula 1, wherein the Lewis base compound contains an acetylacetyl group and two nitrogen elements in its molecular structure, thereby forming a stable film on the respective surfaces of the positive and negative electrodes, while effectively removing byproducts generated due to the thermal decomposition of lithium salts.

[0020] Therefore, since the degradation of the film on the positive and negative electrode surfaces can be prevented by using the lithium secondary battery of the present invention, and the elution of transition metal from the positive electrode can be effectively suppressed, it is possible to realize a lithium secondary battery in which the increase of initial resistance is suppressed and the high-temperature durability is improved. Detailed Implementation

[0021] First, before describing the present invention, it should be understood that the terms or words used in this specification and claims should not be construed as having the meanings defined in commonly used dictionaries, but rather as having meanings and concepts consistent with the technical ideas of the present invention, based on the principle that the inventors can appropriately define the concepts of the terms to best interpret the present invention.

[0022] Furthermore, the terminology used herein is for describing exemplary embodiments only and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0023] It should also be understood that, when used in this specification, the terms “comprising,” “including,” or “having” specify the presence of the stated features, numbers, steps, elements, or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, steps, elements, or combinations thereof.

[0024] In this specification, unless otherwise stated, "%" refers to weight%.

[0025] Before describing the present invention, it should be understood that in the description of "carbon atoms a to b" herein, "a" and "b" refer to the number of carbon atoms contained in a particular functional group. That is, a functional group may include "a" to "b" carbon atoms.

[0026] In this specification, alkyl groups may be straight-chain or branched. They may optionally have substituents. In this specification, unless otherwise defined, "substitution" means that at least one hydrogen atom bonded to a carbon atom is replaced by a non-hydrogen element, for example, by an alkyl group having 1 to 5 carbon atoms or by a fluorine element.

[0027] The invention will be described in more detail below.

[0028] Typically, lithium-ion batteries ensure high-temperature storage performance when the non-aqueous electrolyte solution decomposes during the initial charge / discharge process and forms a passivating film on the surfaces of the positive and negative electrodes. However, this film can be degraded by Lewis acid materials such as HF and PF5, resulting from the thermal decomposition of lithium salts (LiPF6, etc.) widely used in lithium-ion batteries. Specifically, when transition metal elements are eluted from the positive electrode due to attack by Lewis acid materials, the surface structure changes, leading to an increase in the surface resistance of the electrode. Furthermore, the theoretical capacity may decrease due to the loss of metal elements that serve as redox centers, thus reducing the actual capacity. In addition, the eluted transition metal ions, as described above, deposit on the negative electrode, reacting in a strong reduction potential band, consuming electrons, and damaging the film upon deposition, thus exposing the surface of the negative electrode and potentially triggering further decomposition reactions of the non-aqueous electrolyte solution. Consequently, the problem is an increase in negative electrode resistance and irreversible capacity, leading to a continuous decrease in battery capacity.

[0029] Therefore, in order to form a stable film on the electrode surface, the present invention provides a lithium secondary battery comprising a non-aqueous electrolyte solution for lithium secondary batteries, the non-aqueous electrolyte solution containing additives having improved decomposition product removal and SEI enhancement effects.

[0030] Non-aqueous electrolyte solution for lithium secondary batteries

[0031] The present invention provides a non-aqueous electrolyte solution for lithium secondary batteries, the non-aqueous electrolyte solution comprising a lithium salt, an organic solvent and a compound represented by Formula 1 below.

[0032] [Formula 1]

[0033]

[0034] In Formula 1, A is a C1 to C5 alkyl group.

[0035] (1) Lithium salts

[0036] First, lithium salts are described below.

[0037] In the non-aqueous electrolyte solution for lithium secondary batteries according to embodiments of the present invention, any lithium salt can be used without particular limitation, as long as it is commonly used in electrolyte solutions for lithium secondary batteries. For example, the lithium salt may include Li + As a cation, and may include F selected from - Cl - ,Br - I - NO3 - N(CN)2 - BF4 - ClO4 - AlO4 - AlCl4 - PF6 - SbF6 - AsF6 - B 10 Cl 10 - BF2C2O4 - BC4O8 - PF4C2O4 - PF2C4O8 - (CF3)2PF4 - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - CF3SO3 - C4F9SO3 - CF3CF2SO3 - (CF3SO2)2N - (FSO2)2N - CF3CF2(CF3)2CO - (CF3SO2)2CH - CH3SO3 - CF3(CF2)7SO3 - CF3CO2 - CH3CO2 -SCN - and (CF3CF2SO2)2N - At least one of the following groups is used as an anion. Specifically, the lithium salt may include those selected from LiCl, LiBr, LiI, LiBF4, LiClO4, LiAlO4, LiAlCl4, LiPF6, LiSbF6, LiAsF6, and LiB. 10 Cl 10 The lithium salt may include at least one material selected from the group consisting of LiBF4, LiClO4, LiPF6, LiBOB (LiB(C2O4)2), LiCF3SO3, LiTFSI (LiN(SO2CF3)2), LiFSI (LiN(SO2F)2), LiCH3SO3, LiCF3CO2, LiCH3CO2, and LiBETI (LiN(SO2CF2CF3)2). Specifically, the lithium salt may include one material selected from the group consisting of LiBF4, LiClO4, LiPF6, LiBOB (LiB(C2O4)2), LiCF3SO3, LiTFSI (LiN(SO2CF3)2), LiFSI (LiN(SO2F)2), and LiBETI (LiN(SO2CF2CF3)2), or a mixture of two or more thereof, and more specifically, may include LiPF6.

[0038] The lithium salt content can be appropriately varied within the typical range where lithium salts can be used, but in order to obtain the best effect of forming an anti-corrosion film on the electrode surface, lithium salts can be included in the electrolyte solution at a concentration of 0.8M to 3.0M, specifically 1.0M to 3.0M.

[0039] When lithium salts are contained within the above concentration range, the viscosity of the non-aqueous electrolyte solution can be controlled to achieve optimal impregnation, and the mobility of lithium ions can be improved to enhance the capacity and cycle performance of lithium secondary batteries.

[0040] (2) Organic solvents

[0041] In addition, organic solvents will be described below.

[0042] Organic solvents may include cyclic carbonate organic solvents, linear carbonate organic solvents, or mixtures thereof.

[0043] Cyclic carbonate organic solvents are organic solvents with high viscosity and high dielectric constant, and are therefore organic solvents capable of well dissociating lithium salts in non-aqueous electrolyte solutions. Specific examples 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-pentene carbonate, 2,3-pentene carbonate, and vinylene carbonate, and may include ethylene carbonate.

[0044] In addition, linear carbonate organic solvents are organic solvents with low viscosity and low dielectric constant, and representative examples may include at least one organic solvent selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate and ethyl propyl carbonate, and specifically, may include ethyl methyl carbonate (EMC).

[0045] In this invention, a mixture of cyclic carbonate compounds and linear carbonate compounds can be used, wherein the mixing ratio of the cyclic carbonate compounds to the linear carbonate compounds can be in the range of 1:9 to 5:5 by volume, and specifically, it can be from 2:8 to 4:6 by volume. When the mixing ratio of the cyclic carbonate compounds and the linear carbonate compounds meets the above range, a non-aqueous electrolyte solution with high conductivity can be prepared.

[0046] In addition, if desired, the organic solvent may further include cyclic carbonate organic solvents and / or straight-chain ester organic solvents and / or cyclic ester organic solvents other than straight-chain carbonate organic solvents.

[0047] Specific examples of straight-chain ester organic solvents may include at least one organic solvent selected from methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate.

[0048] In addition, cyclic ester organic solvents can be at least one organic solvent selected from the group consisting of γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone and ε-caprolactone.

[0049] In addition, organic solvents may further include at least one of ether organic solvents, amide organic solvents and nitrile organic solvents.

[0050] As an ether-based organic solvent, it can be selected from any one of the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether and ethyl propyl ether, or a mixture of two or more thereof.

[0051] Nitrile solvents may be at least one selected from the group consisting of acetonitrile, propionitrile, butyronitrile, valerate, octanoic acid, heptanoic acid, cyclopentaneformitrile, cyclohexaneformitrile, 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile.

[0052] (3) Electrolyte solution additives

[0053] The non-aqueous electrolyte solution for lithium secondary batteries of the present invention includes a compound represented by Formula 1 as an electrolyte solution additive.

[0054] [Formula 1]

[0055]

[0056] In Formula 1, A is a C1 to C5 alkyl group.

[0057] Specifically, in Formula 1 above, A is a C1 to C4 alkyl group; more specifically, in Formula 1 above, A can be a C1 to C3 alkyl group.

[0058] Preferably, the compound represented by Formula 1 above can be a compound represented by Formula 1a below.

[0059] [Equation 1a]

[0060]

[0061] The compound represented by Formula 1 is a compound comprising an imidazole group and a propargyl group containing two nitrogen elements in its molecular structure, wherein the two nitrogen elements can act as Lewis bases to increase the binding force with Lewis acid materials generated as decomposition products of lithium salts. As a result, byproducts that cause secondary batteries to deteriorate at high temperatures, such as byproducts generated due to the thermal decomposition of lithium salts, can be easily removed. Furthermore, nitrogen (N) atom-based materials can be electrochemically reduced and decomposed to form a nitrogen (N) atom-based SEI film on the negative electrode surface. The nitrogen (N) atom-based film has the property of being retained and not easily decomposed when the battery is exposed to high temperatures. Therefore, by endowing the SEI film with the property of being stably retained on the negative electrode without decomposition, the compound represented by Formula 1 above can control the additional negative electrode reduction reaction of transition metals caused by SEI decomposition and prevent the deposition of transition metals eluted during high-temperature storage on the negative electrode.

[0062] Furthermore, the compound represented by Formula 1 above includes a propargyl group with a triple bond in its molecular structure, which is known to have metal ion adsorption capacity. Therefore, it can readily adsorb metal foreign matter such as Fe, Co, Mn, or Ni eluted from the positive electrode during charging / discharging, metal foreign matter such as Cu eluted from the negative electrode, or metal foreign matter mixed in the raw materials or during manufacturing. As a result, since the growth of eluted metal foreign matter into dendrites in the negative electrode can be suppressed, the abnormal voltage drop caused by eluted metal foreign matter during high-temperature storage can be suppressed. In addition, when a predetermined voltage is reached during charging / discharging, the propargyl group is reduced on the surface of the negative electrode and forms a stable ion-conducting film, thereby suppressing additional electrolyte decomposition reactions. Moreover, even during overcharging or high-temperature storage, it promotes the adsorption and release of lithium ions from the negative electrode, thereby suppressing the abnormal voltage drop of the secondary battery and improving its cycle life properties and high-temperature storage performance.

[0063] In the case of the non-aqueous electrolyte solution for lithium secondary batteries of the present invention, which includes the compound of Formula 1 as an additive, a more robust passivation film can be formed on the surfaces of the positive and negative electrodes. Therefore, the deterioration of the passivation film at high temperatures can be prevented, thereby enabling a lithium secondary battery with improved high-temperature durability.

[0064] Meanwhile, based on the total weight of the non-aqueous electrolyte solution for lithium secondary batteries, the content of the compound represented by Formula 1 above can be from 0.5% by weight to 6.0% by weight.

[0065] When the compound represented by Formula 1 above is included in the above range, a robust film can be formed on the surface of the positive electrode, while suppressing the side reactions, capacity reduction and resistance increase caused by the additive to the greatest extent. This effectively suppresses the elution of transition metals in the positive electrode active material at high temperature and effectively removes the thermal decomposition products of lithium salt, thereby realizing a lithium secondary battery with excellent high-temperature durability.

[0066] In other words, when the content of the electrolyte solution additive for secondary batteries is 0.5% by weight or more, the effect of removing lithium salt thermal decomposition products such as HF or PF5 and suppressing transition metal elution can be maintained more stably by protecting the positive electrode during battery operation. Furthermore, when the content of the compound represented by Formula 1 above is 6.0% by weight or less, the viscosity of the non-aqueous electrolyte solution can be controlled to achieve optimal impregnation, effectively suppressing the increase in electrode resistance caused by additive decomposition, and further increasing the ionic conductivity in the battery, thereby preventing degradation of rate performance or low-temperature lifespan performance during high-temperature storage.

[0067] Specifically, based on the total weight of the non-aqueous electrolyte solution for lithium secondary batteries, the content of the compound represented by Formula 1 above can be from 0.5% by weight to 5.0% by weight, specifically from 0.5% by weight to 3.0% by weight, preferably from 0.5% by weight to 1.0% by weight.

[0068] (4) Other additives

[0069] Furthermore, if necessary, the non-aqueous electrolyte solution of the present invention may further include other additives besides the compound represented by Formula 1 above, to prevent the non-aqueous electrolyte solution from decomposing in a high-output environment and causing negative electrode collapse, or to further improve the low-temperature high-rate discharge properties, high-temperature stability, prevent overcharging, and suppress battery expansion at high temperatures.

[0070] Examples of additives may include at least one selected from the group consisting of cyclic carbonates, halogen-substituted carbonates, sulfonyl lactones, sulfates / salts, phosphates / salts or phosphites / salts, borates / salts, nitriles, benzenes, amines, silanes, and lithium salts.

[0071] Cyclic carbonate compounds can be, for example, vinylene carbonate (VC), vinyl ethylene carbonate, etc.

[0072] Halogen-substituted carbonate compounds can be, for example, fluoroethylene carbonate (FEC).

[0073] Sulfolactone compounds can be, for example, at least one compound selected from the group consisting of 1,3-propanesulfonyl lactone (PS), 1,4-butanesulfonyl lactone, ethylenesulfonyl lactone, 1,3-propenesulfonyl lactone (PRS), 1,4-butenesulfonyl lactone and 1-methyl-1,3-propenesulfonyl lactone.

[0074] Sulfate / salt compounds can be, for example, ethylene sulfate (ESa), trimethylol sulfate (TMS), methyltrimethylol sulfate (MTMS), etc.

[0075] The phosphate ester / salt or phosphite / salt compound can be, for example, one or more compounds selected from the group consisting of lithium difluoro(bis(oxalato)phosphate), lithium difluorophosphate, tris(trimethylsilyl)phosphate, tris(trimethylsilyl)phosphite, tris(2,2,2-trifluoroethyl)phosphate and tris(trifluoroethyl)phosphite.

[0076] Boronate / salt compounds can be tetraphenylboronic acid ester, lithium oxaloyl difluoroborate (LiODFB), lithium bis(oxaloyl)borate (LiB(C2O4)2, LiBOB), etc.

[0077] Nitrile compounds can be, for example, at least one compound selected from the group consisting of succinate, adiponitrile, acetonitrile, propionitrile, butyronitrile, valerate, octanoic acid, heptanoic acid, cyclopentanenitrile, cyclohexanenitrile, 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile.

[0078] Benzene compounds can be, for example, fluorobenzene; amine compounds can be, for example, triethanolamine or ethylenediamine; and silane compounds can be, for example, tetravinylsilane.

[0079] Lithium salt compounds are compounds that are different from lithium salts contained in non-aqueous electrolyte solutions, and can be LiPO2F2 or LiBF4, etc.

[0080] When additional additives include vinylene carbonate, vinyl ethylene carbonate, or succinic anionylene, a more robust SEI film can be formed on the negative electrode surface during the initial activation process of the secondary battery. Furthermore, the inclusion of LiBF4 can suppress gas generation that may occur due to electrolyte solution decomposition during high-temperature storage, thereby improving the high-temperature stability of the secondary battery.

[0081] Other additives may be used in combination of two or more compounds, and based on the total weight of the non-aqueous electrolyte solution, the total content of the compound represented by Formula 1 above and other additives may be less than 50% by weight, specifically from 0.05% by weight to 20% by weight, and more specifically from 0.05% by weight to 10% by weight. When the total content of additives meets the above range, the low-temperature output performance of the battery can be improved, its high-temperature storage performance and high-temperature life performance can be further effectively improved, and battery side reactions caused by additives remaining after the reaction can be prevented.

[0082] Lithium secondary batteries

[0083] Furthermore, another embodiment of the present invention provides a lithium secondary battery comprising the non-aqueous electrolyte solution for lithium secondary batteries of the present invention.

[0084] Specifically, a lithium secondary battery may include a positive electrode, a negative electrode, and the aforementioned non-aqueous electrolyte solution for lithium secondary batteries. More specifically, a lithium secondary battery may include a positive electrode, a negative electrode, a separator between the positive and negative electrodes, and the aforementioned non-aqueous electrolyte solution for lithium secondary batteries.

[0085] Meanwhile, the lithium secondary battery of the present invention can be manufactured by the following process: forming an electrode assembly in which a positive electrode, a separator and a negative electrode are stacked in sequence, housing the electrode assembly in a battery case, and then introducing the non-aqueous electrolyte solution of the present invention into the battery case.

[0086] Typical methods known in the art for manufacturing lithium secondary batteries can be applied to the method of the present invention for manufacturing lithium secondary batteries, which will be described in detail below.

[0087] (1) Positive electrode

[0088] The positive electrode of the present invention may include a positive electrode active material layer comprising a positive electrode active material, and if necessary, the positive electrode active material layer may further include a conductive material and / or an adhesive.

[0089] The positive electrode active material is a compound capable of reversibly intercalating and deintercalating lithium, and may include a lithium transition metal oxide containing one or more metals selected from cobalt, manganese, nickel or aluminum and lithium. Specifically, it may include at least one of lithium manganese-based oxides, lithium iron phosphate or lithium nickel manganese cobalt-based oxides having high capacity performance and battery safety. Specifically, the positive electrode may contain at least one of lithium iron phosphate or lithium nickel manganese cobalt-based oxides.

[0090] Specifically, the lithium manganese-based oxide may be LiMnO2 or LiMn2O4, and the lithium iron phosphate may be, for example, LiFePO4.

[0091] In addition, the lithium nickel manganese cobalt-based oxide may include a lithium transition metal oxide represented by Formula 2 below.

[0092] [Formula 2]

[0093] Li a Ni x Co y M 1 z M 2 w O2

[0094] In Formula 2,

[0095] M 1 is Mn, Al or a combination thereof,

[0096] M 2 is at least one selected from Al, Zr, W, Ti, Mg, Ca and Sr, where 0 ≤ a ≤ 0.5, 0.55 ≤ x < 1.0, 0 < y < 0.4, 0 < z < 0.4, 0 < w ≤ 0.1.

[0097] a represents the atomic fraction of lithium in the lithium nickel-based oxide, where a may satisfy 0.8 ≤ a ≤ 1.2, preferably 0.85 ≤ a ≤ 1.15, more preferably 0.9 ≤ a ≤ 1.2. When the molar ratio of lithium satisfies the above range, the crystal structure of the lithium nickel-based oxide can be formed stably.

[0098] x represents the atomic fraction of nickel in all metal elements other than lithium in the lithium nickel-based oxide, where x may satisfy 0.55 < x ≤ 1.0, especially 0.6 < x < 1.0, more especially 0.7 ≤ x ≤ 1.0, for example 0.8 ≤ x ≤ 0.99, more preferably 0.88 ≤ x ≤ 0.99. When the molar ratio of nickel satisfies the above range, it exhibits a high energy density and can achieve a high capacity.

[0099] y represents the atomic fraction of cobalt in all metal elements other than lithium in the lithium nickel-based oxide, where y can satisfy 0 < y ≤ 0.4, particularly 0 < y ≤ 0.3, more particularly 0.05 ≤ y ≤ 0.3, and more preferably 0.01 ≤ y ≤ 1.12.

[0100] z represents the atomic fraction of element M in all metal elements other than lithium in the lithium nickel-based oxide 1 where z can satisfy 0 < z ≤ 0.4, preferably 0 < z ≤ 0.3, more particularly 0.05 ≤ z ≤ 0.3, and more preferably 0.01 ≤ z ≤ 0.12.

[0101] w represents the atomic fraction of element M in all metal elements other than lithium in the lithium nickel-based oxide 2 where w can satisfy 0 < w ≤ 0.1, preferably 0 < w ≤ 0.05, and more preferably 0 < w ≤ 0.02.

[0102] Specifically, the lithium nickel manganese cobalt-based oxide can include a lithium composite transition metal oxide, such as Li(Ni <00并将其替换为正确的内容,例如: 0.6 Mn 0.2 Co 0.2 )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 Mn 0.15 Co 0.05 )O2, Li(Ni 0.86 Mn <00并将其替换为正确的内容,例如: 0.07 Co 0.05 Al 0.02 )O2 and Li(Ni 0.90 Mn 0.05 Co 0.05 )O2, and preferably includes a lithium transition metal oxide with a nickel content of 70 atm% or more in the transition metal. That is, since the higher the nickel content in the transition metal, the higher the capacity to be achieved, it is more beneficial to use a lithium transition metal oxide with a nickel content of 70 atm% or more to achieve a high capacity. The above lithium composite metal oxide can be at least one selected from Li Li(Ni 0.7 Mn 0.15 Co 0.15 )O2 and Li(Ni 0.8 Mn 0.1 Co 0.1 )O2.

[0103] 请注意,原文中部分标签内容不完整或格式有误,我在翻译时尽量按照正确的格式和内容进行处理。如果还有其他疑问,请随时告诉我。Meanwhile, in addition to lithium transition metal oxides, the positive electrode active material of the present invention may further include lithium cobalt-based oxides (such as LiCoO2, etc.), lithium nickel-based oxides (such as LiNiO2, etc.), lithium nickel manganese-based oxides (such as LiNi 1-Y Mn Y O2(0 < Y < 1) and LiMn 2-z Ni z O4(0 < z < 2)), lithium nickel cobalt-based oxides (such as LiNi 1-Y1 Co Y1 O2(0 < Y1 < 1)), lithium manganese cobalt-based oxides (such as LiCo 1-Y2 Mn Y2 O2(0 < Y2 < 1) and LiMn 2-z1 Co z1 O4(0 < z1 < 2)), etc., at least one of them.

[0104] Based on the total weight of the solids in the positive electrode active material layer, the content of the positive electrode active material can be 90% to 99% by weight, specifically 93% to 98% by weight.

[0105] There is no particular limitation on the conductive material as long as it has conductivity without causing chemical changes in the battery. For example, carbon powders such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black or thermal cracking carbon black can be used; graphite powders such as natural graphite, artificial graphite or graphite with a very developed crystal structure; conductive fibers such as carbon fibers or metal fibers; conductive powders such as fluorocarbon powders, aluminum powders or nickel powders; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; conductive materials such as polyphenylene derivatives, etc.

[0106] Based on the total weight of the solids in the positive electrode active material layer, the addition amount of the conductive material is usually 1% to 30% by weight.

[0107] The binder is a component for improving the adhesion between positive electrode active material particles and the adhesion between the positive electrode active material and the current collector, and is usually added in an amount of 1% to 30% based on the total weight of the solids in the positive electrode active material layer. Examples of the binder can include fluororesin-based binders, including polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE); rubber-based binders, including styrene-butadiene rubber (SBR), nitrile rubber and styrene-isoprene rubber; cellulose-based binders, including carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose and regenerated cellulose; polyvinyl alcohol-based binders, including polyvinyl alcohol; polyolefin-based binders, including polyethylene and polypropylene; polyimide-based binders; polyester-based binders; silane-based binders, etc.

[0108] The positive electrode of the present invention as described above can be manufactured by methods known in the art for manufacturing positive electrodes. For example, the positive electrode can be manufactured by: dissolving or dispersing a positive electrode active material, a binder, and / or a conductive material in a solvent to prepare a positive electrode slurry, coating the positive electrode slurry onto a positive electrode current collector, and then drying and rolling it to form a positive electrode active material layer; or casting the positive electrode active material layer onto a separate carrier, and then pressing the film layer obtained by peeling off the carrier onto the positive electrode current collector, etc.

[0109] There are no particular restrictions on the positive electrode current collector, as long as it is conductive and does not cause chemical changes in the battery. For example, stainless steel, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel with a surface treatment of one of carbon, nickel, titanium, silver, etc., can be used.

[0110] The solvent may include organic solvents such as N-methyl-2-pyrrolidone (NMP) and may be used in an amount such that a preferred viscosity is achieved when the positive electrode active material and optional binders and conductive materials are included. For example, the solvent content may be such that the solids concentration in the active material slurry containing the positive electrode active material and optional binders and conductive materials is 10% to 70% by weight, preferably 20% to 60% by weight.

[0111] (2) Negative electrode

[0112] Next, the negative electrode will be described.

[0113] The negative electrode of the present invention includes a negative electrode active material layer comprising a negative electrode active material, and if desired, the negative electrode active material layer may include a conductive material and / or an adhesive.

[0114] As the negative electrode active material, various negative electrode active materials used in the art can be used, such as carbon-based negative electrode active materials, silicon-based negative electrode active materials, or mixtures thereof.

[0115] According to one embodiment, the negative electrode active material may include a carbon-based negative electrode active material, and various carbon-based negative electrode active materials used in the art can be used as the carbon-based negative electrode active material, such as graphite materials, such as natural graphite, artificial graphite and Kish graphite; high-temperature sintered carbon, such as pyrolytic carbon, mesophase pitch-based carbon fibers, mesophase carbon microspheres, mesophase pitch, petroleum and coal tar pitch-derived coke; soft carbon and hard carbon. There are no particular limitations on the shape of the carbon-based negative electrode active material, and materials of various shapes can be used, such as irregular, planar, sheet-like, spherical or fibrous.

[0116] Preferably, the carbon-based negative electrode active material may include at least one of natural graphite and artificial graphite. More preferably, the carbon-based negative electrode active material may include natural graphite and artificial graphite. When natural graphite and artificial graphite are used together, the adhesion to the current collector can be increased to inhibit the peeling of the active material.

[0117] According to another embodiment, the negative electrode active material may include a silicon-based negative electrode active material, and the silicon-based negative electrode active material may include, for example, at least one selected from the group consisting of metallic silicon (Si), silicon oxide (SiOx, where 0 < x ≤ 2), silicon carbide (SiC), and Si-Y alloy (where Y is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, transition metals, rare earth elements, and combinations thereof, and is not Si). The element Y may be selected from the group consisting of Mg, Ca, Sr, barium (Ba), radium (Ra), Sc, Y, Ti, Zr, hafnium (Hf), (Rf), V, Nb, Ta, (Db), Cr, Mo, W, (Sg), technetium (Tc), rhenium (Re), (Bh), Fe, lead (Pb), ruthenium (Ru), osmium (Os), (Hs), rhodium (Rh), iridium (Ir), palladium (Pd), platinum (Pt), Cu, silver (Ag), gold (Au), Zn, cadmium (Cd), B, Al, Ga, tin (Sn), In, Ti, germanium (Ge), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), sulfur (S), selenium (Se), tellurium (Te), polonium (Po), and combinations thereof.

[0118] Since the silicon-based negative electrode active material has higher capacity characteristics than the carbon-based negative electrode active material, better capacity characteristics can be obtained when the silicon-based negative electrode active material is further included. However, for a negative electrode including a silicon-based negative electrode active material, it contains more oxygen-rich components in the SEI than a graphite negative electrode, and when Lewis acids such as HF or PF5 are present in the electrolyte, the SEI containing oxygen-rich components tends to decompose more easily. Therefore, for a negative electrode containing a silicon-based negative electrode active material, it is necessary to inhibit the formation of Lewis acids such as HF and PF5, or remove (or scavenge) the formed Lewis acids to stably maintain the SEI. The non-aqueous electrolyte of the present invention includes a compound acting as a Lewis base, thereby inhibiting the generation of Lewis acids to inhibit the dissolution of transition metals from the positive electrode and effectively preventing damage to the SEI formed on the surface of the silicon-based negative electrode active material. [[ID=​​​Specific examples of carbon-based and silicon-based anode active materials are the same as those described above.

[0121] The mixing ratio of silicon-based anode active material to carbon-based anode active material by weight can be from 3:97 to 99:1, preferably from 5:95 to 30:70, and more preferably from 5:95 to 15:85. When the mixing ratio of silicon-based anode active material to carbon-based anode active material meets the above range, excellent cycle performance can be ensured because the volume expansion of silicon-based anode active material is suppressed and the capacity characteristics are improved.

[0122] Based on the total weight of the solids in the negative electrode active material layer, the content of the negative electrode active material can be from 80% to 99% by weight. When the amount of negative electrode active material meets the above range, excellent capacity and electrochemical properties can be obtained.

[0123] Conductive materials are components used to further improve the conductivity of the negative electrode active material, and the amount of conductive material added can range from 1% to 20% by weight, based on the total solid weight in the negative electrode active material layer. There are no particular limitations on the conductive material, as long as it is conductive and does not cause chemical changes in the battery. Examples of conductive materials that can be used include: graphite, such as natural or artificial graphite; carbon black, such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermally cracked carbon black; conductive fibers, such as carbon fibers and metal fibers; conductive powders, such as fluorocarbon powders, aluminum powder, and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0124] Adhesives are components used to aid in the bonding between conductive materials, active materials, and current collectors, and their addition amount is typically from 1% to 30% by weight, based on the total solid weight in the negative electrode active material layer. Examples of adhesives may include: fluoropolymer adhesives, including polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); rubber adhesives, including styrene-butadiene rubber (SBR), nitrile rubber, and styrene-isoprene rubber; cellulose adhesives, including carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, and regenerated cellulose; polyvinyl alcohol adhesives, including polyvinyl alcohol; polyolefin adhesives, including polyethylene and polypropylene; polyimide adhesives; polyester adhesives; silane adhesives, etc.

[0125] The negative electrode can be manufactured using methods known in the art. For example, the negative electrode can be manufactured by: preparing a negative electrode slurry by dissolving or dispersing the negative electrode active material and optionally a binder and conductive material in a solvent, applying the negative electrode slurry onto a negative electrode current collector, and then rolling and drying it to form a layer of negative electrode active material; or by casting the negative electrode active material layer onto a separate carrier, and then pressing the film layer obtained by peeling off the carrier onto the negative electrode current collector.

[0126] Negative electrode current collectors typically have a thickness of 3 to 500 μm. There are no particular limitations on the negative electrode current collector, as long as it has high conductivity without causing chemical changes in the battery. Materials used include, for example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel surface-treated with one of carbon, nickel, titanium, or silver, and aluminum-cadmium alloys. Furthermore, similar to the case with the positive electrode current collector, microscopic irregularities can be formed on the surface of the negative electrode current collector to improve the adhesion of the negative electrode active material. The negative electrode current collector can be used in various forms, such as films, sheets, foils, meshes, porous bodies, foams, and nonwoven fabrics.

[0127] The solvent may include water or organic solvents such as NMP or alcohols, and may be used in an amount that achieves a preferred viscosity when the negative electrode active material and optional binders, conductive materials, etc., are included. For example, the solvent content may be such that the solids concentration in the active material slurry containing the negative electrode active material and optional binders and conductive materials is 50% to 75% by weight, preferably 50% to 65% by weight.

[0128] (3) Diaphragm

[0129] The lithium secondary battery of the present invention includes a separator between the positive electrode and the negative electrode.

[0130] The separator is used to separate the negative electrode and the positive electrode and provide a path for the movement of lithium ions. Any separator can be used without particular limitation, as long as it is a separator commonly used in lithium secondary batteries. However, separators with low resistance to the movement of ions in the electrolyte and thus excellent electrolyte moisture retention are particularly preferred.

[0131] Specifically, as a separator, porous polymer membranes can be used, such as porous polymer membranes made from polyolefin polymers like ethylene homopolymers, propylene homopolymers, ethylene / butene copolymers, ethylene / hexene copolymers, and ethylene / methacrylate copolymers, or membranes having two or more stacked layers. Alternatively, typical porous nonwoven fabrics can be used, such as nonwoven fabrics formed from high-melting-point glass fibers, polyethylene terephthalate fibers, etc. Furthermore, coated separators including ceramic components or polymer materials can be used to ensure heat resistance or mechanical strength, and can optionally be used in single-layer or multi-layer structures.

[0132] The lithium secondary battery of the present invention, as described above, can be usefully used in portable devices such as mobile phones, laptops and digital cameras, as well as electric vehicles such as hybrid electric vehicles (HEVs).

[0133] Therefore, according to another embodiment of the present invention, a battery module including a lithium secondary battery as a unit cell is provided, and a battery pack including the battery module is provided.

[0134] Battery modules or battery packs can be used as a power source for one or more medium to large-sized devices, such as power tools, electric vehicles such as electric vehicles (EVs), hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), and energy storage systems.

[0135] The shape of the lithium secondary battery of the present invention is not particularly limited, but it can be cylindrical, square, bag-shaped, coin-shaped, etc.

[0136] The lithium secondary battery of the present invention can be used as a battery cell for powering small devices, and can also preferably be used as a unit cell for medium and large battery modules comprising multiple battery cells.

[0137] The present invention will be described in detail below with reference to embodiments.

[0138] In this regard, embodiments of the present invention can be modified into various other forms, and the scope of the present invention should not be construed as limited to the embodiments described below. Embodiments of the present invention are provided to describe the invention more fully to those skilled in the art.

[0139] The present invention will be described in detail below with reference to specific embodiments.

[0140] Example

[0141] Example 1

[0142] (Preparation of non-aqueous electrolyte solutions)

[0143] After dissolving LiPF6 in a non-aqueous organic solvent (in which ethylene carbonate (EC): ethyl methyl carbonate (EMC) are mixed in a volume ratio of 30:70) to achieve a LiPF6 concentration of 1.0 M, a non-aqueous electrolyte solution for lithium secondary batteries is prepared by adding 0.5 wt% of the compound represented by Formula 1a and 0.5 wt% of ethylene carbonate (VC).

[0144] (Manufacturing of secondary batteries)

[0145] The positive electrode active material (Li(Ni) 0.8 Co 0.1 Mn 0.1Carbon black (using O2 and NMC811) as conductive material and polyvinylidene fluoride (PVDF) as binder were added to N-methyl-2-pyrrolidone (NMP) as solvent in a weight ratio of 97.5:1:1.5 to prepare a positive electrode slurry (50% by weight solids). The positive electrode slurry was coated onto a 15 μm thick positive electrode current collector (Al film) and dried, then rolled to manufacture the positive electrode.

[0146] A negative electrode slurry (60% by weight solids) was prepared by adding the negative electrode active material (graphite:SiO weight ratio = 95:5), binder (SBR-CMC), and conductive material (carbon black) to water as a solvent in a weight ratio of 95:3.5:1.5. The negative electrode slurry was coated onto a 6 μm thick copper (Cu) film as the negative electrode current collector and dried, then rolled to manufacture the negative electrode.

[0147] An electrode assembly is fabricated by sequentially stacking a positive electrode, a polyolefin porous membrane with inorganic particles (Al2O3) applied thereon, and a negative electrode.

[0148] The assembled electrode assembly is housed in a battery case, and 6 mL of the prepared non-aqueous electrolyte solution is injected into it to manufacture a stacked cell (capacity: 2 Ah).

[0149] Example 2

[0150] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 1.0 wt% of the compound represented by Formula 1a and 0.5 wt% of vinylene carbonate (see Table 1 below).

[0151] Example 3

[0152] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 3.0 wt% of the compound represented by Formula 1a and 0.5 wt% of vinylene carbonate (see Table 1 below).

[0153] Example 4

[0154] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 5.0 wt% of the compound represented by Formula 1a and 0.5 wt% of vinylene carbonate (see Table 1 below).

[0155] Example 5

[0156] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 6.0 wt% of the compound represented by Formula 1a and 0.5 wt% of vinylene carbonate (see Table 1 below).

[0157] Comparative Example 1

[0158] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 3.0 wt% of vinylene carbonate (see Table 1 below).

[0159] Comparative Example 2

[0160] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 3.0 wt% of the compound represented by Formula 3 and 0.5 wt% of vinylene carbonate (see Table 1 below).

[0161] [Formula 3]

[0162]

[0163] Comparative Example 3

[0164] The lithium secondary battery was manufactured in the same manner as in Example 1, except that after dissolving LiPF6 in a non-aqueous organic solvent to a concentration of 1.0 M, a non-aqueous electrolyte solution for the lithium secondary battery was prepared by adding 3.0 wt% of the compound represented by Formula 4 and 0.5 wt% of vinylene carbonate (see Table 1 below).

[0165] [Formula 4]

[0166]

[0167] Table 1

[0168]

[0169] In Table 1 above, VC is an abbreviation for vinylene carbonate.

[0170] Experimental Example

[0171] Experiment Example 1: Evaluation of Initial Resistance

[0172] The lithium secondary batteries manufactured in Examples 1 to 5 and the lithium secondary batteries manufactured in Comparative Examples 1 to 3 were each charged to 4.2V at a rate of 0.33C under constant current / constant voltage conditions at room temperature (25°C), discharged to 50% depth of discharge (DOD) to meet SOC 50%, and then discharged at a rate of 2.5C for 10 seconds to measure their initial resistance using a PNE-0506 charger / discharger (manufacturer: PNE solution). The results are shown in Table 2 below.

[0173] Table 2

[0174] Initial resistance (mΩ) Example 1 5.23 Example 2 5.31 Example 3 5.65 Example 4 5.89 Example 5 7.54 Comparative Example 1 8.56 Comparative Example 2 10.35 Comparative Example 3 11.98

[0175] Referring to Table 2 above, it can be seen that the initial resistance of each secondary battery in Embodiments 1 to 5 of the present invention is less than about 7.54 mΩ.

[0176] Meanwhile, it can be seen that, compared with each of the secondary batteries in Examples 1 to 5, the initial resistance of the secondary battery in Comparative Example 1, which does not contain the electrolyte solution additive of the present invention, the secondary battery in Comparative Example 2, which contains the compound represented by Formula 3, and the secondary battery in Comparative Example 3, which contains the compound represented by Formula 4, all increased.

[0177] Experimental Example 2: Evaluation of capacitance retention and resistivity increase at high temperature (45℃)

[0178] The lithium secondary batteries prepared in Examples 1 to 5 and the lithium secondary batteries prepared in Comparative Examples 1 to 3 were each charged to 4.2V at a rate of 0.33C under constant current / constant voltage conditions at 45°C, and then discharged to 3V at a rate of 0.33C under constant current / constant voltage conditions. This was set as one cycle, and then 200 charge / discharge cycles were performed to measure the capacity retention rate (%) and the resistance increase rate (%). The capacity retention rate (%) was calculated according to Equation 1 below, and the resistance increase rate (%) was calculated according to Equation 2 below. The measurement results are shown in Table 3 below.

[0179] [Equation 1]

[0180] Capacity retention (%) = (Discharge capacity after 200 cycles / Discharge capacity after 1 cycle) × 100

[0181] [Equation 2]

[0182] Resistance improvement rate (%) = {(resistance after 200 cycles - resistance after 1 cycle) / resistance after 1 cycle} × 100

[0183] Table 3

[0184]

[0185] Referring to Table 3 above, it can be seen that the capacity retention rate (%) of each secondary battery in Examples 1 to 5 of the present invention is approximately 92.40% or more after 200 cycles, and its resistance increase rate (%) is approximately 5.34% or less. In other words, it can be seen that as the additive content increases, the capacity retention rate improves and the resistance increase rate decreases. This phenomenon appears to occur because when the additive content increases, the amount of residual additive remaining after initial consumption increases, and the residual additive is used to regenerate the SEI that decomposes during cycling, thereby suppressing further decomposition reactions, resulting in improved capacity retention and increased resistance increase rate.

[0186] However, as shown in Table 2 of Experimental Example 1, a drawback of including a slightly larger amount of additive in the secondary battery of Experimental Example 5 is that the film resistance increases in the initial stage, resulting in a higher initial resistance. Therefore, considering the initial resistance of the secondary battery, it seems necessary to appropriately control the range of additive content.

[0187] Meanwhile, it can be seen that the capacity retention rate (%) and resistance increase rate (%) of the secondary battery of Comparative Example 1, which does not contain the electrolyte solution additive of the present invention, the secondary battery of Comparative Example 2, which contains the compound represented by Formula 3, and the secondary battery of Comparative Example 3, which contains the compound represented by Formula 4, are worse than those of each secondary battery of Examples 1 to 5 after 200 cycles.

[0188] Experimental Example 3: Evaluation of Volume Increase Rate After High-Temperature Storage

[0189] The lithium secondary batteries prepared in Examples 1 to 5 and the lithium secondary batteries prepared in Comparative Examples 1 to 3 were each charged to 4.2V at a rate of 0.33C under constant current / constant voltage conditions at room temperature (25°C), discharged to 50% depth of discharge (DOD) to meet SOC 50%, and then discharged at a rate of 2.5C for 10 seconds to measure the initial thickness.

[0190] Subsequently, each lithium secondary battery was stored at 60°C for two weeks, and its thickness after high-temperature storage was measured. The results are shown in Table 4 below.

[0191] Table 4

[0192] Volume increase rate (%) Example 1 10.47 Example 2 9.57 Example 3 8.54 Example 4 7.21 Example 5 7.02 Comparative Example 1 23.20 Comparative Example 2 21.46 Comparative Example 3 20.23

[0193] Referring to Table 4 above, it can be seen that, compared with the secondary batteries of Comparative Examples 1 to 3, the volume increase rate (%) of the secondary batteries of Examples 1 to 5 of the present invention after high-temperature storage is improved.

Claims

1. A lithium secondary battery, comprising: A cathode containing positive electrode active materials; A negative electrode containing a negative electrode active material; The membrane between the negative electrode and the positive electrode; and A non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution comprises: Lithium salts; Organic solvents; and Compounds represented by Formula 1: [Formula 1] in, In Equation 1, A is a C1 to C5 alkyl group.

2. The lithium secondary battery as described in claim 1, wherein, In Formula 1, A is a C1 to C4 alkyl group.

3. The lithium secondary battery as described in claim 2, wherein, In Formula 1, A is a C1 to C3 alkyl group.

4. The lithium secondary battery as described in claim 1, wherein, The compound represented by Formula 1 is the same as the compound represented by Formula 1a: [Equation 1a] 5. The lithium secondary battery as described in claim 1, wherein, Based on the total weight of the non-aqueous electrolyte solution, the content of the compound represented by Formula 1 is from 0.5% to 6.0% by weight.

6. The lithium secondary battery as described in claim 5, wherein, Based on the total weight of the non-aqueous electrolyte solution, the content of the compound represented by Formula 1 is from 0.5% by weight to 5.0% by weight.

7. The lithium secondary battery as described in claim 1, wherein, The lithium salt includes at least one selected from the group consisting of LiBF4, LiClO4, LiPF6, LiB(C2O4)2, LiCF3SO3, LiN(SO2CF3)2, LiN(SO2F)2 and LiN(SO2CF2CF3)2.

8. The lithium secondary battery as described in claim 1, wherein, The organic solvents include cyclic carbonate organic solvents, linear carbonate organic solvents, or combinations thereof.

9. The lithium secondary battery as described in claim 8, wherein, The cyclic carbonate organic solvent comprises at least one selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentene carbonate, 2,3-pentene carbonate, and vinylene carbonate.

10. The lithium secondary battery as described in claim 8, wherein, The linear carbonate organic solvent comprises at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate, and ethyl propyl carbonate.

11. The lithium secondary battery as described in claim 1, wherein, The organic solvents include cyclic carbonate organic solvents and linear carbonate organic solvents.

12. The lithium secondary battery as described in claim 11, wherein, The volume ratio of the cyclic carbonate organic solvent to the linear carbonate organic solvent is 1:9 to 5:

5.

13. The lithium secondary battery as described in claim 1, wherein, The non-aqueous electrolyte solution further comprises at least one additive selected from the group consisting of halogen-substituted or unsubstituted carbonate compounds, sulfonyl lactone compounds, sulfate / salt compounds, phosphate / salt or phosphite / salt compounds, borate / salt compounds, nitrile compounds, amine compounds, silane compounds and lithium salt compounds.

14. The lithium secondary battery as described in claim 1, wherein, The positive electrode active material comprises lithium and at least one metal selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe) and aluminum (Al).

15. The lithium secondary battery as described in claim 1, wherein, The negative electrode active material includes at least one of carbon-based negative electrode active materials or silicon-based negative electrode active materials.

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