Specification Title of the invention: Non-aqueous electrolyte and lithium secondary battery containing the same Technical field [One] Mutual citation with related applications [2] This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0026545 filed on March 06, 2018, and all contents disclosed in the documents of the Korean patent application are included as part of this specification. [3] Technical field [4] The present invention relates to a non-aqueous electrolyte and a lithium secondary battery including the same, and more particularly, a non-aqueous electrolyte and a lithium secondary battery including the same, which can maintain the capacity characteristics and life characteristics of the battery above a certain level and have high high-temperature safety. It is about. Background [5] 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 have been commercialized and widely used. [6] In a lithium secondary battery, a positive electrode active material and a negative electrode active material are applied to a current collector with an appropriate thickness, or the 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 can or It is manufactured by putting an electrode assembly in a similar container and then injecting an electrolyte. [7] In general, lithium metal oxide is used as a positive electrode active material, and lithium metal, a lithium alloy, crystalline or amorphous carbon, or a carbon composite is used as the negative electrode active material. In addition, in general, an electrolyte in which an appropriate amount of salt is dissolved in a non-aqueous organic solvent is mainly used, for example, ethylene carbonate, propylene carbonate, dimethoxyethane, gamma butyrolactone, N,N-dimethylformamide, tetrahydro Furan or acetonitrile or the like is used. [8] However, when stored for a long time at a high temperature, organic solvents generally cause oxidation reactions and generate gas to deform the stable structure of the battery, and lead to internal short-circuit when internal heat generation by overcharging or overdischarging, causing the battery to ignite or explode. It can cause problems. [9] In order to solve this problem, a method of using a separator having a high melting point has been proposed. However, there is a problem in that the thickness of the separator must be increased in order to increase the melting point of the separator. In addition, in the case of polyolefin-based films, which are generally used for separators, the melting point is before/after 150℃, so if internal heat is rapidly generated due to oxidation reaction of the electrolyte during overcharging, it still suppresses battery ignition and explosion due to short circuit inside the battery. There is a limit that it is difficult to do. [10] Therefore, development of an electrolyte solution that has excellent oxidation stability and can effectively suppress battery ignition and/or explosion is required. [11] (Patent Document 0001) Japanese Laid-Open Patent Publication No. 1996-185847 [12] Detailed description of the invention Technical challenge [13] An object of the present invention is to solve the above problems, and to provide a non-aqueous electrolyte solution and a lithium secondary battery including the same, while maintaining the capacity characteristics and life characteristics of a battery above a certain level and having excellent high-temperature safety. [14] Means of solving the task [15] In one aspect, the present invention is an ionic solution containing at least one anion and a cation selected from the group consisting of bis (fluorosulfonyl) imide anion and bis (trifluoromethane) sulfonyl imide anion, lithium It provides a non-aqueous electrolyte for a lithium secondary battery comprising a salt, a phosphite additive, and a surfactant including an oligomer represented by the following Formula 1. [16] [Formula 1] [17] [18] In Formula 1, R 0 and R 0 ′ are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R and R′ are each independently an aliphatic, alicyclic or aromatic hydrocarbon group, and R ``, R''' are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, a is an integer of 1 to 3, b is an integer of 0 to 2, and m1 and m3 are each It is independently an integer selected from 1 to 15, m2 is an integer selected from 1 to 10, and x is an integer selected from 1 to 15. [19] In another aspect, the present invention provides a lithium secondary battery including a positive electrode, a negative electrode, a separator interposed between the positive and negative electrodes, and a non-aqueous electrolyte for the lithium secondary battery. [20] Effects of the Invention [21] The non-aqueous electrolyte solution for a lithium secondary battery according to the present invention has excellent electrochemical safety and uses a flame-retardant ionic solution as a solvent for the non-aqueous electrolyte solution, and at the same time, a phosphite-based additive capable of suppressing side reactions of the electrolyte solution by removing oxygen radicals. By using it, a non-aqueous electrolyte solution for a lithium secondary battery with improved high temperature safety can be prepared. [22] Further, by using the fluorine-substituted oligomer together as a surfactant, the wettability of the electrolyte is improved, so that the capacity characteristics and life characteristics of the battery can also be maintained above a certain level. [23] Best mode for carrying out the invention [24] Hereinafter, the present invention will be described in more detail to aid understanding of the present invention. At this time, the terms or words used in the specification and claims should not be interpreted as being limited to a conventional or dictionary meaning, and the inventor appropriately defines the concept of the term 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. [25] When'include','have','consists of' and the like mentioned in the present specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise. [26] In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description. [27] In this specification, "X to Y" indicating a range means "X or more and Y or less." [28] Hereinafter, the non-aqueous electrolyte according to the present invention will be described in detail. [29] [30] Nonaqueous electrolyte [31] The non-aqueous electrolyte solution according to the present invention includes an ionic solution including an anion, a cation, and a non-aqueous solvent, a lithium salt, a phosphite-based additive, and a surfactant. Hereinafter, each component of the non-aqueous electrolyte composition according to the present invention will be described. [32] The electrolyte of a lithium secondary battery used in the related art includes a part of a lithium salt in order to improve conductivity in an organic solvent. When the lithium salt is included, there is a problem in that an oxidation reaction of the electrolyte solution occurs. [33] When the electrolyte causes an oxidation reaction, the temperature inside the battery may increase due to the reaction heat generated by the oxidation reaction, and thus the temperature may reach a temperature above the ignition point. At this time, when surrounding oxygen participates, there is a problem that ignition and thermal runaway may occur, and thus an explosion phenomenon of the lithium secondary battery may occur. In order to solve this problem, research on a method of inhibiting the electrolytic solution from causing an oxidation reaction has been continued. [34] Therefore, in the present invention, an ionic solution that is electrochemically safe and exhibits oxidation resistance is used as a non-aqueous electrolyte solvent, so that the oxidation decomposition reaction of the electrolyte can be suppressed, and a phosphite-based additive is used during the oxidative decomposition reaction, The generation of oxygen radicals can be suppressed, and thus a non-aqueous electrolyte for a lithium secondary battery having excellent battery life characteristics and capacity characteristics can be provided. [35] Specifically, in the non-aqueous electrolyte solution for a lithium secondary battery according to an embodiment of the present invention, the anions included in the ionic solution are bis (fluorosulfonyl) imide anions (FSI anions) and bis (trifluoromethane). It may include at least one anion selected from the group consisting of sulfonylimide anion (TFSI anion). [36] In addition, the cation included in the ionic solution may include at least one cation selected from the group consisting of cations represented by the following Formulas 2-1 to 2-5. [37] [Formula 2-1] [38] [39] In Formula 2-1, R 1 , R 2 , R 3 and R 4 are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms. [40] [Formula 2-2] [41] [42] In Formula 2-2, R 5 and R 6 are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms. [43] [Formula 2-3] [44] [45] In Formula 2-3, R 7 and R 8 are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms. [46] [Formula 2-4] [47] [48] In Formula 2-4, R 9 , R 10 , R 11 and R 12 are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms. [49] [Formula 2-5] [50] [51] In Formula 2-5, R 13 , R 14 , R 15 and R 16 are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms. [52] [53] For example, the cation represented by Formula 2-1 may be at least one cation selected from the group consisting of cations represented by Formulas 2-1a and 2-1b below. [54] [Formula 2-1a] [55] [56] [Formula 2-1b] [57] [58] For example, the cation represented by Formula 2-2 may be at least one cation selected from the group consisting of cations represented by Formulas 2-2a and 2-2b below. [59] [Formula 2-2a] [60] [61] [Formula 2-2b] [62] [63] For example, the cation represented by Formula 2-3 may be at least one cation selected from the group consisting of cations represented by Formulas 2-3a and 2-3b below. [64] [Formula 2-3a] [65] [66] [Formula 2-3b] [67] [68] For example, the cation represented by Formula 2-5 may be a cation represented by Formula 2-5a. [69] [Formula 2-5a] [70] [71] Meanwhile, the non-aqueous solvent is a solvent commonly used in electrolytes for lithium secondary batteries, for example, ethers, esters (Acetates, Propionates), amides, linear carbonates or cyclic carbonates, nitriles (acetonitrile, SN, etc.). May be used alone or in combination of two or more. [72] Among them, a carbonate-based electrolyte solvent including a carbonate compound, which is typically a cyclic carbonate, a linear carbonate, or a mixture thereof, may be used. [73] Specific examples of the cyclic carbonate compound include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene There is a single compound or a mixture of at least two or more selected from the group consisting of carbonates, vinylene carbonates, and halides thereof. In addition, specific examples of the linear carbonate compound include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethylmethyl carbonate (EMC), methylpropyl carbonate (MPC), and ethylpropyl carbonate (EPC). A compound selected from the group consisting of or a mixture of at least two or more may be representatively used, but is not limited thereto. [74] In particular, among the carbonate-based electrolyte solvents, propylene carbonate and ethylene carbonate, which are cyclic carbonates, are highly viscous organic solvents and can be preferably used because they dissociate lithium salts in the electrolyte well due to their high dielectric constant. These cyclic carbonates include ethylmethyl carbonate and diethyl carbonate. Alternatively, if a low viscosity, low dielectric constant linear carbonate such as dimethyl carbonate is mixed and used in an appropriate ratio, an electrolyte solution having a high electrical conductivity can be prepared, and thus it may be more preferably used. [75] In addition, the esters in the electrolyte solvent include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, γ-valerolactone, γ-caprolactone, α-valerolactone And a single compound selected from the group consisting of ε-caprolactone or a mixture of at least two or more may be used, but is not limited thereto. [76] The ionic solution may be included in an amount of 1 part by weight to 50 parts by weight, preferably 5 parts by weight to 40 parts by weight, more preferably 10 parts by weight to 30 parts by weight, based on 100 parts by weight of the non-aqueous electrolyte solution for a lithium secondary battery. have. [77] Next, the lithium salt is used to provide lithium ions in a lithium secondary battery. For example, as the lithium salt, those commonly used in an electrolyte for a lithium secondary battery may be used without limitation. For example, as the cation Li + and include, as an anion F - , Cl - , Br - , I - , NO 3 - , N (CN) 2 - , BF 4 - , ClO 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 4F 9 SO 3 - , CF 3 CF 2 SO 3 - , (CF 3 SO 2 ) 2 N - , (FSO 2 ) 2 N - , (F 2 SO 2 ) 2 N - , CF 3 CF 2 (CF 3 ) 2 CO - , (CF 3 SO 2) 2 CH - , 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 - , at least one or more selected from the group consisting of It may contain an anion. More specifically, as the anion contained in the lithium salt, PF 6 - , (CF 3 SO 2 ) 2 N - and (FSO 2 ) 2 N - may be at least one or more anions selected from the group consisting of. The lithium salt may be used alone or in combination of two or more as necessary. [78] The concentration of the lithium salt may be 0.5M or more, specifically 0.5M to 4M, specifically 0.7M to 4M, and more specifically 0.9M to 3M. [79] When the concentration of the lithium salt satisfies the above range, it is possible to secure high ion transport characteristics (ie, a cation transport rate (transference number)) of the lithium cation (Li+) by increasing the amount of lithium cation present in the non-aqueous electrolyte, It is possible to improve the problem that the reduction safety of the ionic solution is deteriorated. Therefore, it is possible to implement an effect of improving the output characteristics of the lithium secondary battery. In addition, it is possible to prevent an exothermic reaction at a high temperature from appearing at the initial stage of the reaction by adding an effect of improving flame retardancy. In this case, when the concentration of the electrolyte salt is 4M or more, the viscosity of the electrolyte increases significantly, so it is difficult to secure the transfer speed of lithium ions, the wetting characteristics of the electrolyte decrease, and battery performance may rather decrease. [80] Next, the phosphite-based additive is for removing oxygen radicals generated by the oxidation reaction of the electrolyte and the collapse reaction of the anode under high temperature conditions. Is discharged in the form of oxygen radicals, and thus the anode structure is collapsed. On the other hand, if the oxygen radical generator, by this the oxygen radical reaction the phosphite-based additive, it becomes, forming a phosphate, removing the oxygen radicals, oxygen radical scavengers (O 2 to act as radical scavenger), oxygen It is possible to suppress the generation of radicals in a chain (see Scheme 1 below). [81] [Scheme 1] [82] [83] For example, as the phosphite-based additive, a compound represented by the following Formula 3-1 may be used. [84] [Formula 3-1] [85] [86] In Formula 3-1, [87] The R 17 , R 18 and R 19 are each independently hydrogen, fluorine, chlorine, bromine, iodine, -CF 3 , -CH 2 CF 3 , -CF 2 CCl 3 , -C(CF 3 ) 3 , -C (CF 2 F 3 ) 3 , -Si(CH 3 ) 3 , -Si(CH 2 CH 3 ) 3 , -Si(CF 3 ) 3 , -Si(CF 2 CF 3) 3 , -CCl 3 , -CCl 2 CCl 3 , -C(CCl 3 ) 3 , -C(CCl 2 Cl 3 ) 3 , -CBr 3 , -CBr 2 CBr 3 , -C(CBr 3 ) 3 ,- C(CBr 2 Br 3 ) 3 , -CI 3 , -CI 2 CI 3 , -C(CI 3 ) 3 and -C(CI 2CI 3 ) is at least one functional group selected from the group consisting of 3 . [88] More specifically, the compound represented by Formula 3-1 may be at least one compound selected from the group consisting of the following Formulas 3-1a and 3-1b. [89] [Chemical Formula 3-1a] [90] [91] [Formula 3-1b] [92] [93] The phosphite-based additive is included in an amount of 1 to 30 parts by weight, preferably 2 to 25 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the non-aqueous electrolyte for a lithium secondary battery. I can. When the content of the phosphite-based additive satisfies the above range, generation of oxygen radicals can be suppressed to improve high-temperature safety, and side reactions can be minimized. [94] Next, the surfactant including the oligomer represented by Chemical Formula 1 is for improving the wettability of the non-aqueous electrolyte for a lithium secondary battery, thereby improving the capacity characteristics and life characteristics of the battery. [95] [Formula 1] [96] [97] In Formula 1, R 0 and R 0 ′ are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R and R′ are each independently an aliphatic, alicyclic or aromatic hydrocarbon group, and R ``, R''' are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, a is an integer of 1 to 3, and b is an integer of 0 to 2. m1 and m3 are each independently an integer selected from 1 to 15, preferably one integer selected from 5 to 10. m2 is one integer selected from 1 to 10, and preferably one integer selected from 1 to 5. [98] The x is one integer selected from 1 to 15, and preferably one integer selected from 1 to 10. [99] Since the oligomer represented by Formula 1 contains a urethane group (-NHC(O)O-) in the main chain, it has excellent solubility in an ionic solution, and a unit containing fluorine (F) having hydrophobicity is used as the main chain. And hydrophilic (meth)acrylate is located at the end of the main chain. Accordingly, when the oligomer is included as described above, the polyolefin-based compound, which is a component of the separator, is also a hydrophobic material in the battery, and the wettability of the electrolyte is improved by the unit having the hydrophobicity of the oligomer. When the wettability of the electrolyte is improved, since the electrolyte can be uniformly located in the battery, polarization that may occur during charging and discharging of the lithium secondary battery can be minimized, thereby improving the life characteristics of the battery. [100] In one embodiment, the oligomer represented by Formula 1 may be an oligomer represented by Formula 1a. [101] [Formula 1a] [102] [103] In Formula 1a, m1 and m3 are each independently an integer selected from 1 to 15, preferably an integer selected from 3 to 15, and x is an integer selected from 1 to 15 , Preferably it is an integer selected from 1 to 10. [104] [105] The oligomer represented by Formula 1 may be included in an amount of 0.01 parts by weight to 10 parts by weight, preferably 0.5 parts by weight to 10 parts by weight, based on 100 parts by weight of the non-aqueous electrolyte for a lithium secondary battery. When the content of the oligomer represented by Chemical Formula 1 satisfies the above range, the resistance of the lithium secondary battery, the movement of lithium ions, and the resulting decrease in ionic conductivity are minimized, while improving the wettability of the non-aqueous electrolyte solution containing the ionic solution. I can make it. [106] The weight average molecular weight (MW) of the oligomer represented by Formula 1 may be adjusted by the number of repeating units in the oligomer constituting the oligomer, about 1,000 g/mol 100,000 g/mol, specifically 1,000 g/mol to 50,000 g/mol, more specifically 1,000 g/mol to 10,000 g/mol. When the weight average molecular weight of the oligomer is within the above range, the affinity between the oligomer and the ionic solution is improved, the solubility of the oligomer is improved, and the surface tension between the electrolyte and the separator using a hydrophobic compound is reduced, thereby wetting the electrolyte ( wetting) phenomenon can be improved. [107] The weight average molecular weight may refer to a value converted to standard polystyrene measured by gel permeation chromatography (GPC), and unless otherwise specified, the molecular weight may refer to a weight average molecular weight. For example, in the present invention, measurements are made using Agilent's 1200 series under GPC conditions, and the used column may be Agilent's PL mixed B column, and THF may be used as a solvent. [108] In addition, the non-aqueous electrolyte for a lithium secondary battery of the present invention may further include other additives to suppress side reaction reactions in the films formed on the surfaces of the positive and negative electrodes, and specifically, N,N'-dichlorohexylcar At least one compound selected from the group consisting of bodyimide (DCC), vinylene carbonate, saturated sultone, cyclic sulfite, acyclic sulfone, alkylsilyl compound, and inorganic compound may be further included as an additive. [109] The dichlorohexylcarbodiimide (DCC) inhibits the generation of HF generated when lithium salt is ionized and the generation of by-products caused by salt anions, and ultimately suppresses side reactions in the anode and cathode coatings to improve resistance. Can be expected. [110] Representative examples of the saturated sultone include 1,3-propane sultone (PS) and 1,4-butane sultone, and unsaturated sultones include ethene sultone, 1,3-propene sultone, and 1,4-butene sultone. Or 1-methyl-1,3-propene sultone, etc. are mentioned. [111] Representative examples of the cyclic sulfite are ethylene sulfite (Esa), methyl ethylene sulfite, ethyl ethylene sulfite, 4,5-dimethyl ethylene sulfite, 4,5-diethyl ethylene sulfite, propylene sulfite, 4, 5-dimethyl propylene sulfite, 4,5-diethyl propylene sulfite, 4,6-dimethyl propylene sulfite, 4,6-diethyl propylene sulfite, or 1,3-butylene glycol sulfite. have. [112] [113] Lithium secondary battery [114] Next, a lithium secondary battery according to the present invention will be described in detail. [115] The lithium secondary battery according to the present invention includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte solution for the lithium secondary battery. [116] Specifically, the lithium secondary battery can be prepared by injecting the non-aqueous electrolyte for a lithium secondary battery 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 and negative electrodes. [117] In this case, the positive electrode, the negative electrode, and the separator constituting the electrode assembly may be all those that have been manufactured and used in a conventional method when manufacturing a lithium secondary battery. [118] First, the positive electrode may be manufactured by forming a positive electrode mixture layer on a 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. [119] 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. [120] In addition, the positive electrode active material is a compound capable of reversible intercalation and deintercalation of lithium, and specifically includes a lithium composite metal oxide including lithium and at least one metal such as cobalt, manganese, nickel or aluminum. can do. 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