Title of the invention: Non-aqueous electrolyte and lithium secondary battery containing the same Technical field [One] Cross-reference with related application(s) [2] This application claims the benefit of priority based on Korean Patent Application No. 2018-0116475 filed on September 28, 2018, and all contents disclosed in the documents of the Korean patent application are incorporated as part of this specification. [3] [4] Technical field [5] The present invention relates to a non-aqueous electrolyte having improved high and low temperature stability, and a lithium secondary battery having improved high temperature storage characteristics, low temperature output characteristics, and cycle life characteristics by including the same. Background [6] As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing, and among these secondary batteries, lithium secondary batteries having high energy density and voltage are commercialized and widely used. [7] In a lithium secondary battery, an electrode active material is applied to a current collector with an appropriate thickness, or the electrode active material itself is formed in a film shape of an appropriate length, and then wound or stacked together with a separator as an insulator to manufacture an electrode assembly, and the can or It is prepared by storing in a similar container and then injecting an electrolyte. [8] In such a lithium secondary battery, charging and discharging are performed while repeating a process in which lithium ions are intercalated and deintercalated from the lithium metal oxide of the positive electrode to the graphite electrode of the negative electrode. At this time, since lithium is highly reactive, it reacts with the carbon electrode to generate Li 2 CO 3 , LiO, LiOH, etc. to form a film on the surface of the negative electrode. [9] This film is called a solid electrolyte (SEI) film, and the SEI film formed at the beginning of charging prevents the reaction between lithium ions and a carbon negative electrode or other materials during charging and discharging. In addition, it serves as an ion tunnel, allowing only lithium ions to pass. The ion tunnel serves to prevent the collapse of the structure of the carbon negative electrode by solvating lithium ions and causing organic solvents of a high molecular weight electrolyte to move together with the carbon negative electrode. [10] Therefore, in order to improve the high-temperature storage characteristics and cycle life characteristics of the lithium secondary battery, a solid SEI film must be formed on the negative electrode of the lithium secondary battery. Once the SEI film is formed at the time of initial charge, it prevents the reaction between lithium ions and the negative electrode or other materials when charging and discharging is repeated after using the battery. You will play a role. [11] By adjusting the type or amount of non-aqueous organic solvent, electrolyte additive, or lithium salt contained in the conventional electrolyte to the required amount, the surface of the anode is decomposed when stored at high temperature, or the irreversible capacity of the secondary battery is reduced by continuous reaction between the cathode and the electrolyte due to deterioration of the SEI film. There was a problem of increasing and deteriorating output characteristics. [12] In order to improve this, an organic solvent including ethylene carbonate (EC), which can improve output characteristics, has been used instead of a propylene carbonate solvent that can cause an irreversible decomposition reaction with a graphite material. [13] However, since the ethylene carbonate has a high melting point, the use temperature is limited, it is difficult to maintain high-temperature characteristics, and there is a disadvantage of causing a significant decrease in battery performance at low temperatures. [14] Accordingly, there is a need to develop a technology for providing a non-aqueous electrolyte solution having improved high temperature storage characteristics and cycle life characteristics by improving the disadvantages that may occur when ethylene carbonate is used as an organic solvent. [15] Prior art literature [16] Republic of Korea Patent Publication No. 2017-0110995 Detailed description of the invention Technical challenge [17] In order to solve the above problems, an object of the present invention is to provide a non-aqueous electrolyte with improved high and low temperature stability by minimizing the content of ethylene carbonate, which is a first organic solvent, while including an oligomer having a specific structure. [18] In addition, the present invention is to provide a lithium secondary battery having excellent high-temperature storage characteristics, low-temperature output characteristics, and cycle life characteristics by including the non-aqueous electrolyte. Means of solving the task [19] Specifically, in one embodiment of the present invention [20] 1.2M to 3.3M lithium salt, [21] A first organic solvent consisting of ethylene carbonate, [22] A second organic solvent other than ethylene carbonate, and [23] It contains an oligomer represented by the following formula 1 as a first additive, [24] The first organic solvent provides a non-aqueous electrolyte solution containing 0.1% to 12% by weight based on the total weight of the non-aqueous electrolyte. [25] [Formula 1] [26] [27] In Formula 1, [28] R 1 is a substituted or unsubstituted group having 1 to 5 carbon atoms in the alkylene group or ring R with at least one fluorine element 1 'is -O-, wherein R 1 ' is C 1 -C substituted or unsubstituted with at least one fluorine element 5 Is an alkylene group of, [29] R 2 is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element or R 2 ′-O-, wherein R 2 ′ is 1 to 5 carbon atoms unsubstituted or substituted with at least one fluorine element Is an alkylene group of, [30] R 3 is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element or R 3 ′-O-, wherein R 3 ′ is 1 to 5 carbon atoms unsubstituted or substituted with at least one fluorine element Is an alkylene group of, [31] R 4 is an aliphatic hydrocarbon group or an aromatic hydrocarbon group, [32] R a and R b are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, [33] m and n are each independently an integer of 1 to 5, [34] a and b are each independently an integer of 1 to 3. [35] [36] In addition, another embodiment of the present invention provides a lithium secondary battery including the non-aqueous electrolyte according to the present invention. Effects of the Invention [37] The non-aqueous electrolyte solution of the present invention may include a high-concentration lithium salt and an oligomer having a specific structure to improve the impregnation property of the non-aqueous electrolyte solution. In addition, the non-aqueous electrolyte solution of the present invention contains 10% by weight or less of ethylene carbonate, which has low oxidation stability and thermal safety, and reduces resistance due to Li ion depletion during high-rate charging and discharging, thereby improving high-temperature and low-temperature stability. . Accordingly, when the non-aqueous electrolyte solution of the present invention containing an oligomer of a specific structure and 10% by weight or less of ethylene carbonate is used, a secondary battery having improved high-temperature storage characteristics, low-temperature output characteristics, and cycle life characteristics can be implemented. Best mode for carrying out the invention [38] Hereinafter, the present invention will be described in more detail to aid understanding of the present invention. At this time, terms or words used in the present specification and claims should not be construed as being limited to a conventional or dictionary meaning, and the inventor appropriately defines the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of ​​the present invention based on the principle that it can be done. [39] Meanwhile, terms used in the present specification are only used to describe exemplary embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. [40] In the present specification, terms such as "comprise", "include" or "have" are intended to designate the existence of a feature, number, step, component, or a combination of the implemented features, but one or more other features or It is to be understood that the possibility of the presence or addition of numbers, steps, elements, or combinations thereof is not preliminarily excluded. [41] In this specification, "%" means% by weight unless otherwise indicated. [42] Prior to describing the present invention, in the description of "carbon number a to b" in the specification, "a" and "b" mean the number of carbon atoms included in a specific functional group. That is, the functional group may include "a" to "b" carbon atoms. For example, "an alkylene group having 1 to 5 carbon atoms" is an alkylene group containing a carbon atom having 1 to 5 carbon atoms, that is, -CH 2 -, -CH 2 CH 2 -, -CH 2 CH 2 CH 2 -,- It means CH 2 (CH 2 )CH-, -CH(CH 2 )CH 2 -and -CH(CH 2 )CH 2 CH 2 -. [43] In this case, the term "alkylene group" refers to a branched or unbranched divalent unsaturated hydrocarbon group. In one embodiment, the alkylene group may be substituted or unsubstituted. The alkylene group includes, but is not limited to, a methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, tert-butylene group, pentylene group, 3-pentylene group, and the like, and each of these It may be optionally substituted in other embodiments. [44] In addition, in the present specification, "substitution" means that at least one hydrogen bonded to carbon is substituted with an element other than hydrogen, unless otherwise defined, for example, an alkyl group having 1 to 5 carbon atoms or a fluorine element Means substituted with. [45] In addition, in the present invention, unless otherwise specified, "*" refers to the same or different atoms or a connected portion between the terminal portions of the chemical formula. [46] In addition, in the present specification, "molecular weight" means a weight average molecular weight (Mw) unless otherwise defined. [47] [48] The inventors of the present invention have conducted research to improve the high and low temperature properties of a non-aqueous electrolyte containing ethylene carbonate, which has low oxidation stability and thermal stability as an organic solvent. When the low ethylene carbonate content is adjusted to 10% by weight or less, furthermore, when a high-concentration lithium salt of 1.2M or more is included, it was found that the high-temperature storage characteristics and low-temperature output characteristics of the non-aqueous electrolyte were improved, and the present invention was completed. [49] [50] Non-aqueous electrolyte [51] Specifically, the non-aqueous electrolyte solution of the present invention [52] 1.2M to 3.3M lithium salt, [53] A first organic solvent consisting of ethylene carbonate, [54] A second organic solvent other than ethylene carbonate, and [55] It contains an oligomer represented by the following formula 1 as a first additive, [56] The first organic solvent is included in an amount of 0.1% to 12% by weight based on the total weight of the non-aqueous electrolyte. [57] [Formula 1] [58] [59] In Formula 1, [60] R 1 is a substituted or unsubstituted group having 1 to 5 carbon atoms in the alkylene group or ring R with at least one fluorine element 1 'is -O-, wherein R 1 ' is C 1 -C substituted or unsubstituted with at least one fluorine element 5 Is an alkylene group of, [61] R 2 is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element or R 2 ′-O-, wherein R 2 ′ is 1 to 5 carbon atoms unsubstituted or substituted with at least one fluorine element Is an alkylene group of, [62] R 3 is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element or R 3 ′-O-, wherein R 3 ′ is 1 to 5 carbon atoms unsubstituted or substituted with at least one fluorine element Is an alkylene group of, [63] R 4 is an aliphatic hydrocarbon group or an aromatic hydrocarbon group, [64] R a and R b are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, [65] m and n are each independently an integer of 1 to 5, [66] a and b are each independently an integer of 1 to 3. [67] [68] (1) lithium salt [69] A lithium salt The lithium salt used for typical non-aqueous electrolyte solution, the lithium salt in detail the Li cation + a, and the anion include F - , Cl - , Br - , I - , NO 3 - , N (CN ) 2 - , ClO 4 - , BF 4 - , AlO 4 - , AlCl 4 - , PF 6 - , SbF 6 - , AsF 6 - , BF 2 C 2 O 4 -, BC 4 O 8 - , (CF 3 ) 2 PF 4 - , (CF 3 ) 3 PF 3 - , (CF 3 ) 4 PF 2 - , (CF 3 ) 5 PF - , (CF 3 ) 6 P - , CF 3 SO 3 - , C 4 F 9 SO 3 - , CF 3 CF 2 SO 3 - , (CF 3 SO 2 ) 2 N - , (FSO 2 ) 2 N - , CF 3 CF 2 (CF 3 ) 2 CO - , (CF 3 SO 2 ) 2 CH - , (SF 5 ) 3 C - , (CF 3SO 2 ) 3 C - , CF 3 (CF 2 ) 7 SO 3 - , CF 3 CO 2 - , CH 3 CO 2 - , SCN - , and (CF 3 CF 2 SO 2 ) 2 N - one selected from the group consisting of One may be included, and in addition to these, a lithium salt commonly used in an electrolyte solution of a lithium secondary battery may be used without limitation. [70] Specifically, the lithium salt is LiCl, LiBr, LiI, LiBF 4 , LiClO 4 , LiB 10 Cl 10 , LiAlCl 4 , LiAlO 4 , LiPF 6 , LiCF 3 SO 3 , LiCH 3 CO 2 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiCH 3 SO 3 , LiFSI (Lithium bis(fluorosulfonyl)imide, LiN(SO 2 F) 2), LiBETI (lithium bisperfluoroethanesulfonimide, LiN(SO 2 CF 2 CF 3 ) 2 and LiTFSI (lithium (bis) trifluoromethanesulfonimide, LiN(SO 2 CF 3 ) 2 )), a single substance or a mixture of two or more selected from the group consisting of And, more specifically, LiPF 6 , Li(CF 3 SO 2 ) 2 N, Li(FSO 2 ) 2 N, and Li(CF 3 CF 2 SO 2 ) 2 N To include at least any one or more selected from the group consisting of I can. [71] The lithium salt may be appropriately changed within a range that is usually usable, but in order to obtain an optimum effect of forming a film for preventing corrosion on the electrode surface, 1.2M or more, such as 1.2M to 3.3M, specifically 1.5M to 3.3M, more Specifically, it may be 2M to 3.2M. [72] In most secondary batteries at present, the reaction heat generated by an electrochemical (ex. overcharge) or chemical (ex. hot box) reaction increases the internal temperature of the battery, and when the temperature reaches a temperature above the ignition point, it is combined with surrounding oxygen. There is a problem that the secondary battery is ignited due to a thermal-runaway phenomenon. Accordingly, it is emerging as a very important factor to lower the calorific value of the electrolyte in order to increase the high temperature safety of the secondary battery. [73] In the case of the non-aqueous electrolyte solution of the present invention, it is possible to reduce resistance due to depletion of lithium ions during high rate charging and discharging by including a high-concentration lithium salt of 1.2M or more, particularly 1.5M or more. [74] Moreover, in the non-aqueous electrolyte of the present invention, when the concentration of the lithium salt satisfies the above range, high ion transport properties of lithium cations (Li + ) due to an increase in lithium cations present in the non-aqueous electrolyte (i.e., cation transport A transmission number) can be secured, and the effect of improving the cycle capacity characteristics can be achieved by achieving the effect of reducing the diffusion resistance of lithium ions. At this time, when the concentration of the lithium salt is 3.3M or less, specifically 3.2M or less, it is possible to prevent an increase in the viscosity of the electrolyte solution while securing a moving speed of lithium ions. On the other hand, when the maximum concentration of the lithium salt exceeds 3.3M, the viscosity of the non-aqueous electrolyte may be excessively increased, so that the impregnating property of the electrolyte may be reduced. [75] [76] (2) the first organic solvent [77] The first organic solvent may include ethylene carbonate, based on the total weight of the non-aqueous electrolyte, 0.1% to 12% by weight, specifically 1% to 10% by weight, more specifically 3% to 10% by weight It can be included in %. [78] As a solvent having a high dielectric constant of ethylene carbonate, when used in an electrolytic solution, there is an advantage in that the ionic conductivity of the electrolytic solution can be increased and output characteristics can be improved. However, in the case of the ethylene carbonate, since the melting point is high and it is difficult to maintain the properties at high temperature, the use temperature is limited, and oxidation stability and thermal stability are reduced during high temperature storage. [79] Accordingly, in the present invention, the first organic solvent, ethylene carbonate, is included in an amount of 12% by weight or less, specifically 10% by weight or less based on the total weight of the non-aqueous electrolyte, thereby increasing the ionic conductivity of the non-aqueous electrolyte to secure output characteristics. At the same time, it is possible to secure high-temperature storage characteristics and low-temperature output characteristics of the non-aqueous electrolyte. On the other hand, if the content of ethylene carbonate, which is the first organic solvent, is less than 0.1% by weight, it is difficult to form a solid SEI film, so the irreversible capacity of the secondary battery increases due to the continuous side reaction of the negative electrode and the electrolyte, and the output characteristics decrease. I can. In addition, when the content of ethylene carbonate exceeds 10% by weight, particularly 12% by weight, the oxidation stability and low-temperature performance of the non-aqueous electrolyte are inferior, and thus, oxidation and decomposition reactions of the non-aqueous electrolyte such as overcharge and hot box may The storage characteristics and cycle life characteristics of the non-aqueous electrolyte solution tend to decrease under the exothermic environment that affects them. [80] [81] (3) Second organic solvent [82] The second organic solvent is not particularly limited as long as it can minimize decomposition due to oxidation reactions or the like during the charging and discharging process of the secondary battery, and can exhibit the desired properties with additives. It may include at least one organic solvent selected from the group consisting of a solvent, a linear carbonate-based organic solvent, a linear ester-based organic solvent, and a cyclic ester-based organic solvent. [83] Cyclic carbonate-based organic solvents excluding ethylene carbonate are specific examples thereof: propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3 -It may contain at least one organic solvent selected from the group consisting of pentylene carbonate, vinylene carbonate, and fluoroethylene carbonate (FEC). [84] In addition, the linear carbonate-based organic solvent is a specific example of the dimethyl carbonate (dimethyl carbonate, DMC), diethyl carbonate (diethyl carbonate, DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate and ethyl propyl carbonate. It may contain at least one or more organic solvents selected from the group consisting of, among which ethylmethyl carbonate (EMC) may be included. [85] The linear ester organic solvent is a specific example of 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. Can include. [86] The cyclic ester-based organic solvent may include at least one organic solvent selected from the group consisting of γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone, and ε-caprolactone. I can. [87] Specifically, in the present invention, in order to prepare a non-aqueous electrolyte solution having a high ionic conductivity, it is preferable to mix and use a linear carbonate-based organic solvent having a low viscosity and a low dielectric constant together with the first organic solvent. [88] In addition, in the present invention, at least one of a cyclic carbonate-based organic solvent, a linear ester-based organic solvent, and a cyclic ester-based organic solvent other than the first solvent is added to the mixed solvent of the first organic solvent and the linear carbonate-based organic solvent. Can also be included as [89] The second organic solvent may be included in a residual amount excluding the first organic solvent and additives based on the total weight of the non-aqueous electrolyte. [90] [91] (4) first additive [92] The non-aqueous electrolyte solution of the present invention may include an oligomer represented by the following Formula 1 as a first additive in order to lower viscosity and surface tension. [93] [Formula 1] [94] [95] In Formula 1, [96] R 1 is a substituted or unsubstituted group having 1 to 5 carbon atoms in the alkylene group or ring R with at least one fluorine element 1 'is -O-, wherein R 1 ' is C 1 -C substituted or unsubstituted with at least one fluorine element 5 Is an alkylene group of, [97] R 2 is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element or R 2 ′-O-, wherein R 2 ′ is 1 to 5 carbon atoms unsubstituted or substituted with at least one fluorine element Is an alkylene group of, [98] R 3 is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element or R 3 ′-O-, wherein R 3 ′ is 1 to 5 carbon atoms unsubstituted or substituted with at least one fluorine element Is an alkylene group of, [99] R 4 is an aliphatic hydrocarbon group or an aromatic hydrocarbon group, [100] R a and R b are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, [101] m and n are each independently an integer of 1 to 5, [102] a and b are each independently an integer of 1 to 3. [103] [104] In general, when the lithium salt in the non-aqueous electrolyte solution contains a high concentration of 1.2 M or more, the viscosity of the non-aqueous electrolyte solution may increase and the electrolyte wetting characteristics may be reduced. In the present invention, by including the oligomer represented by Formula 1 as the first additive, the viscosity and surface tension of the non-aqueous electrolyte solution increased by the high concentration lithium salt may be lowered. [105] That is, in the case of a polymer having a general alkylene oxide skeleton used in a conventional non-aqueous electrolyte, the reduction safety is low, and a film that is easily destroyed at high temperature is formed on the surface of the negative electrode during initial charging. This film has a disadvantage of increasing the interface resistance between the electrode and the electrolyte by causing a side reaction. [106] On the other hand, the oligomer represented by Formula 1 of the present invention contains an acrylate functional group, which is a hydrophilic group capable of forming crosslinks on both ends of the main chain, and at the same time, urethane (-NC(O)O Since it contains a -) group and a fluorine-substituted alkylene group, it exhibits a balanced affinity with the anode or separator (SRS layer), which is a hydrophilic part, and the cathode or membrane fabric, which is a hydrophobic part, and can give the role of a surfactant. [107] Therefore, the non-aqueous electrolyte solution of the present invention further includes an oligomer represented by Chemical Formula 1, although it contains a high-concentration lithium salt of 1.2 M or more, particularly 1.5 M or more, and thereby lowers the surface tension with the electrode. Since the resistance can be improved, an effect of improving the impregnation of the electrode and the electrolyte can be obtained. [108] Moreover, the oligomer represented by Chemical Formula 1 is electrochemically stable and has high reduction safety, and has the ability to dissociate lithium salts, thereby minimizing the reduction reaction on the surface of the negative electrode and improving lithium ion mobility. . [109] Therefore, in the case of the non-aqueous electrolyte solution of the present invention containing the oligomer represented by Formula 1, a polymer having an alkylene oxide skeleton such as ethylene oxide, propylene oxide, or butylene oxide, which has been commercialized during the production of the conventional non-aqueous electrolyte solution, Alternatively, as compared with a non-aqueous electrolyte solution using dialkyl siloxane, fluorosiloxane, and block copolymers and graft polymers having these units, side reactions with the electrode are reduced, and the interface safety effect between the electrode and the electrolyte is improved. , It is possible to improve the initial output characteristics and cycle life characteristics of the lithium secondary battery. [110] [111] Meanwhile, in Formula 1, R 4 may be an aliphatic hydrocarbon group. [112] The aliphatic hydrocarbon group may include an alicyclic hydrocarbon group or a linear hydrocarbon group. Specifically, the alicyclic hydrocarbon group is a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms; A substituted or unsubstituted C4 to C20 cycloalkenylene group; And at least one or more selected from the group consisting of a substituted or unsubstituted heterocycloalkylene group having 2 to 20 carbon atoms. [113] The linear hydrocarbon group is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; A substituted or unsubstituted C 1 to C 20 alkoxyl group; A substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms; And at least one selected from the group consisting of a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms. [114] In addition, in Formula 1, R 4 may be an aromatic hydrocarbon group. [115] The aromatic hydrocarbon group is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms; Or a substituted or unsubstituted C2-C20 heteroarylene group is mentioned. [116] Specifically, in Formula 1, R 1 is R 1 ′-O-, wherein R 1 ′ is an alkylene group having 1 to 5 carbon atoms substituted or unsubstituted with at least one fluorine element, and R 2 is R 2 ′ -O- and, wherein R 2 'is a substituted or unsubstituted alkylene group having 1 to 5 rings with at least one elemental fluorine, R 3 is substituted with at least one fluorine element or unsubstituted alkyl group having 1 to 5 carbon atoms a group, wherein R 4 is may be an aliphatic hydrocarbon. [117] More specifically, in Formula 1, R 1 is R 1 ′-O-, wherein R 1 ′ is an alkylene group having 1 to 3 carbon atoms unsubstituted or substituted with at least one fluorine element, and R 2 is R 2 'is -O-, wherein R 2 ' is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms ring with at least one elemental fluorine, R 3 is 1 to 3 carbon atoms substituted or unsubstituted with at least one fluorine element an alkylene group, wherein R 4 is may be an aliphatic hydrocarbon. [118] More specifically, the oligomer represented by Formula 1 may be an oligomer represented by Formula 1a. [119] [Formula 1a] [120] [121] In Formula 1a, [122] m1 and n1 are each independently an integer of 1 to 5. [123] Specifically, in Formula 1a, m1 and n1 are each independently an integer of 3 to 5. [124] [125] In addition, the oligomer represented by Formula 1 may be included in 0.1% to 22% by weight, specifically 0.1% to 20% by weight, specifically 0.5% to 10% by weight based on the total weight of the non-aqueous electrolyte. [126] When the content of the first additive is 0.1% by weight or more, the surface tension may be lowered to improve the impregnation property of the non-aqueous electrolyte solution to the electrode. Accordingly, it is possible to prevent disadvantages such as an increase in resistance, a decrease in capacity and a limitation of movement of lithium ions, for example, a decrease in ionic conductivity. [127] On the other hand, the weight average molecular weight (MW) of the oligomer represented by Formula 1 can be controlled by the number of repeating units, specifically 1,000 g/mol to 100,000 g/mol, more specifically 1,000 g/mol to It may be 50,000 g/mol, more specifically 1,000 g/mol to 10,000 g/mol. Preferably, the weight average molecular weight (MW) of the oligomer represented by Formula 1 may be 1,000 g/mol to 5,000 g/mol. [128] When the weight average molecular weight of the oligomer is within the above range, the mechanical strength of the non-aqueous electrolyte solution including the oligomer can be effectively improved. [129] If the weight average molecular weight of the oligomer represented by Chemical Formula 1 is less than 1,000 g/mol, appropriate mechanical strength cannot be expected, and the use of a more polymerization initiator is required, or a difficult additional polymerization process is required. There is a disadvantage that the process becomes complicated. On the other hand, when the weight average molecular weight exceeds 100,000 g/mol, the oligomer physical properties themselves become rigid, and the affinity with the electrolyte solvent decreases, making it difficult to dissolve, and thus formation of a uniform and excellent gel polymer electrolyte cannot be expected. [130] The weight average molecular weight can be measured using Gel Permeation Chromatography (GPC). For example, after preparing a sample sample of a certain concentration, the GPC measurement system alliance 4 device is stabilized. When the device is stabilized, a standard sample and a sample sample are injected into the device to obtain a chromatogram, and then the molecular weight can be calculated according to the analysis method (system: Alliance 4, column: Ultrahydrogel linearX2, eluent: 0.1M NaNO 3 (pH 7.0). phosphate buffer, flow rate: 0.1 mL/min, temp: 40℃, injection: 100μL) [131] [132] (5) second additive [133] In addition, the non-aqueous electrolyte solution of the present invention contains at least one of a fluorine-containing aromatic compound having 9 or less carbon atoms, a carbonate ester compound having an unsaturated bond, and an acid anhydride in order to improve the storage characteristics and cycle characteristics of the non-aqueous electrolyte solution when overcharged . It may contain more. [134] Specifically, the fluorine-containing aromatic compound having 9 or less carbon atoms is fluorobenzene, 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 1,2,3- Trifluorobenzene, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1,2,3,4-tetrafluorobenzene, 1,2,3,5-tetrafluoro Lobenzene, 1,2,4,5-tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene, 2-fluorotoluene, 3-fluorotoluene, 4-fluorotoluene, 2,3-difluoro Rotoluene, 2,4-difluorotoluene, 2,5-difluorotoluene, 2,6-difluorotoluene, 3,4-difluorotoluene, benzotrifluoride, 2-fluorobenzotri Fluoride, 3-fluorobenzo trifluoride, 4-fluorobenzo trifluoride, 3-fluoro-o-xylene, 4-fluoro-o-xylene, 2-fluoro-m-xylene , 5-fluoro-m-xylene, 2-methylbenzo trifluoride, 3-methylbenzo trifluoride, 4-methylbenzo trifluoride and at least one selected from the group consisting of octafluorotoluene. I can. [135] The fluorine-containing aromatic compound is preferably included in an amount of 0.01% by weight or more and 10% by weight or less, specifically 0.1% by weight to 5% by weight or less, based on the weight of the non-aqueous electrolyte. If the content of the fluorine-containing aromatic compound is less than 0.01% by weight, the effect of improving overcharge safety is insignificant, and if it exceeds 10% by weight, excessive side reactions in the electrolyte may occur during charging and discharging of the battery due to increased resistance due to excessive additives. There is a possibility. [136] In addition, the carbonate ester compound having an unsaturated bond is specific examples thereof, vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 4,5-dimethylvinylene carbonate, 4,5-diethyl vinylene carbonate, fluoroethylene Vinylene carbonate compounds such as carbonate or trifluoromethyl vinylene carbonate; 4-vinyl ethylene carbonate, 4-methyl-4-vinyl ethylene carbonate, 4-ethyl-4-vinyl ethylene carbonate, 4-n-propyl-4-vinyl ethylene carbonate, 5-methyl-4-vinyl ethylene carbonate, 4, Vinyl ethylene carbonate such as 4-divinyl ethylene carbonate or 4,5-divinyl ethylene carbonate; It may contain at least one or more methylene ethylene carbonate compounds such as 4,4-dimethyl-5-methylene ethylene carbonate or 4,4-diethyl-5-methylene ethylene carbonate. Among them, vinylene carbonate, 4-vinyl ethylene carbonate, 4-methyl-4-vinyl ethylene carbonate or 4,5-divinyl ethylene carbonate, particularly vinylene carbonate or 4-vinyl ethylene carbonate are preferred, and two or more of them It can be mixed and used. [137] The cyclic carbonate ester compound having an unsaturated bond is preferably included in an amount of 0.01% by weight or more and 10% by weight or less, specifically 0.1% by weight to 5% by weight or less based on the total weight of the non-aqueous electrolyte. If it is less than 0.01% by weight, the effect of improving the cycle characteristics may be insignificant, and if it exceeds 10% by weight, gas is generated during storage at high temperature and the internal pressure of the battery may increase. [138] In addition, representative examples of the acid anhydride are succinic anhydride, glutaric anhydride, maleic anhydride, cytraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxyl anhydride, cyclopentane And an anhydride of at least one carboxyl group selected from the group consisting of tetracarboxylic dianhydride and phenylsuccinic anhydride. [139] The acid anhydride is preferably included in an amount of 0.01% by weight or more and 10% by weight or less, specifically 0.1% by weight to 5% by weight or less based on the total weight of the non-aqueous electrolyte. If it is less than 0.01% by weight, the effect of improving the cycle characteristics may be insignificant, and if it exceeds 10% by weight, there is a possibility that side reactions in the non-aqueous electrolyte solution excessively occur during charging and discharging of the battery. [140] [141] (6) additional additives [142] In addition, the non-aqueous electrolyte for a lithium secondary battery of the present invention can form a more stable ion conductive film on the electrode surface if necessary in order to further improve the low-temperature high-rate discharge characteristics, high-temperature stability, overcharge prevention, and swelling improvement effect during high-temperature storage. It may further include additional additives that may be. [143] Representative examples of the additional additives include at least one compound selected from the group consisting of a sultone compound, a sulfate compound, a nitrile compound, a phosphate compound, a borate compound, and a lithium salt compound. [144] The sultone-based compound is 1,3-propane sultone (PS), 1,4-butane sultone, ethene sultone, 1,3-propene sultone (PRS), 1,4-butene sultone, and 1-methyl-1, And at least one compound selected from the group consisting of 3-propene sultone. [145] The sulfate-based compound may include ethylene sulfate (Esa), trimethylene sulfate (TMS), or methyl trimethylene sulfate (MTMS), and 3 based on the total weight of the non-aqueous electrolyte. It may be included in weight percent or less. [146] The nitrile compounds are succinonitrile (SN), adiponitrile (Adn), acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanenitrile, cyclopentane carbonitrile, cyclohexane carbonitrile , 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile At least one or more compounds selected from are mentioned. [147] The nitrile-based compound may be 5% to 8% by weight, specifically 6% to 8% by weight based on the total weight of the non-aqueous electrolyte. When the total weight of the nitrile-based compound in the non-aqueous electrolyte solution exceeds 8% by weight, resistance increases due to an increase in the film formed on the electrode surface, and battery performance may deteriorate. [148] The phosphate-based compound is at least one compound selected from the group consisting of lithium difluoro (bisoxalato) phosphate, lithium difluoro phosphate, trimethyl silyl phosphate, and tris (2,2,2-trifluoroethyl) phosphate For example, it may be included in an amount of 3% by weight or less based on the total weight of the non-aqueous electrolyte. [149] The borate-based compound may include tetraphenylborate or lithium oxalyldifluoroborate, and may be included in an amount of 3% by weight or less based on the total weight of the non-aqueous electrolyte. [150] The lithium salt-based compound is a lithium salt different from the compound contained in the nonaqueous electrolytic solution, LiPO 2 F 2 , LiODFB, LiBOB (lithium bis oxalate reyito borate (LiB (C 2 O 4 ) 2 ), and LiBF 4 from the group consisting of One or more selected compounds may be mentioned, and may be included in an amount of 3% by weight or less based on the total weight of the non-aqueous electrolyte. [151] Two or more of the additives may be mixed and included, and the total weight of the additives may be 20% by weight or less, specifically 0.01 to 20% by weight, specifically 0.1 to 10% by weight, based on the total weight of the non-aqueous electrolyte. , Preferably it may be 0.1 to 5% by weight. When the content of the additives exceeds 20% by weight, there is a possibility that side reactions in the non-aqueous electrolyte solution excessively occur during charging and discharging of the battery. In particular, when the additives for forming the SEI film are added in an excessive amount, they may not be sufficiently decomposed at high temperature, and thus may be present as unreacted or precipitated in the electrolyte at room temperature. Accordingly, a side reaction may occur in which the lifespan or resistance characteristics of the secondary battery are deteriorated. [152] [153] Lithium secondary battery [154] In addition, the present invention can provide a lithium secondary battery including the non-aqueous electrolyte solution described above. [155] 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 disposed between the positive electrode and the negative electrode, and the aforementioned non-aqueous electrolyte. [156] Specifically, the lithium secondary battery of the present invention can be manufactured by injecting the non-aqueous electrolyte of the present invention into an electrode assembly formed by sequentially stacking a positive electrode, a negative electrode, and a separator selectively interposed between the positive electrode and the negative electrode. At this time, the positive electrode, the negative electrode, and the separator constituting the electrode assembly may be all those conventionally used in manufacturing a lithium secondary battery. [157] The positive and negative electrodes constituting the lithium secondary battery of the present invention may be manufactured and used in a conventional manner. [158] [159] (1) anode [160] The positive electrode may be manufactured by forming a positive electrode mixture layer on the positive electrode current collector. The positive electrode mixture layer may be formed by coating a positive electrode slurry including a positive electrode active material, a binder, a conductive material, and a solvent on a positive electrode current collector, followed by drying and rolling. [161] The positive electrode current collector is not particularly limited as long as it has conductivity without causing chemical changes to the battery, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon on the surface of aluminum or stainless steel. , Nickel, titanium, silver, or the like may be used. [162] The positive electrode active material is a compound capable of reversible intercalation and deintercalation of lithium, and specifically, may include at least one metal such as cobalt, manganese, nickel, or aluminum, and a lithium composite metal oxide containing lithium. have. More specifically, the lithium composite metal oxide is a lithium-manganese oxide (eg, LiMnO 2 , LiMn 2 O 4, etc.), a lithium-cobalt oxide (eg, LiCoO 2, etc.), a lithium-nickel oxide (E.g., LiNiO 2 ), lithium-nickel-manganese oxide (e.g., LiNi 1-Y Mn Y O 2 (here, 0