Title of the invention: Electrolyte composition for lithium secondary battery and lithium secondary battery comprising 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. 2017-0164113 filed December 01, 2017 and Korean Patent Application No. 2018-0151896 filed November 30, 2018, and all disclosed in the documents of the corresponding Korean patent application The content is incorporated as part of this specification. [3] [4] Technical field [5] The present invention relates to an electrolyte composition for a lithium secondary battery and a lithium secondary battery including the same. Background [6] Recently, as the electric, electronic, telecommunication and computer industries are rapidly developing, the demand for high performance, high stability secondary batteries is gradually increasing. In particular, according to the trend of miniaturization and weight reduction of these electronic (communication) devices, thin film and miniaturization of lithium secondary batteries, which are core parts in this field, are required. [7] Lithium secondary batteries have been mainly used as an electrolyte in a liquid state, for example, an ion conductive organic liquid electrolyte in which an electrolyte salt is dissolved in a non-aqueous organic solvent. However, in the case of using a liquid electrolyte, there is a disadvantage in that the electrode material is degraded and the organic solvent is highly likely to be volatilized, and stability is low due to combustion due to an increase in ambient temperature and the temperature of the battery itself. In particular, lithium secondary batteries have a problem in that gas is generated inside the battery due to the decomposition of the carbonate organic solvent and/or side reactions between the organic solvent and the electrode during charging and discharging, thereby expanding the battery thickness. The amount of gas generated is further increased. [8] As such, the continuously generated gas causes an increase in the internal pressure of the battery, causing a phenomenon in which the center of a specific surface of the battery is deformed, such as the prismatic battery swelling in a specific direction, as well as local differences in adhesion at the electrode surface in the battery This causes the problem that the electrode reaction does not occur equally on the entire electrode surface. [9] Accordingly, research has recently been made to commercialize a polymer electrolyte such as a gel polymer electrolyte instead of a liquid electrolyte. [10] The gel polymer electrolyte has excellent electrochemical stability compared to a liquid electrolyte, so that the thickness of the battery can be kept constant, and a stable thin-film battery can be manufactured due to the inherent adhesion of the gel. [11] A secondary battery to which such a gel polymer electrolyte is applied can be manufactured by the following two methods. [12] First, a monomer or polymer having a polymerizable site in a liquid electrolyte in which a salt is dissolved in a non-aqueous organic solvent is dissociated with a polymerization initiator to prepare a composition for a liquid gel polymer electrolyte, and then a positive electrode, a negative electrode, and a separator are wound. Alternatively, there is an injection-type method of injecting into a secondary battery containing a stacked electrode assembly and then gelling (crosslinking) at an appropriate temperature and time to prepare a gel polymer electrolyte. [13] Alternatively, a liquid gel polymer electrolyte composition is coated on one or both surfaces of at least one of the electrode and the separator, and then gelled using heat or UV to form a gel polymer electrolyte on the surface of the electrode or separator. There is a coating type method of assembling a secondary battery using. [14] In the case of the injection type method, compared to the coating type method, there is an advantage in that the electrolyte solution wetting is excellent. There is a disadvantage in that pre-gelation occurs due to the reaction. [15] Accordingly, it is not easy to perform the injection process, and when pre-gelation occurs before curing, the wetting property of the battery may be deteriorated, and various performances such as high temperature stability of the battery may be deteriorated. [16] Therefore, it is necessary to develop a technology for manufacturing a gel polymer electrolyte in which pre-gelation is prevented. [17] [18] Prior art literature [19] Korean Patent Application Publication No. 2003-0089721 Detailed description of the invention Technical challenge [20] The present invention is to provide a thermosetting electrolyte composition for a lithium secondary battery comprising a polymerizable polymer capable of gelation by heat. [21] In addition, the present invention is to provide a gel polymer electrolyte for a lithium secondary battery prepared by thermal polymerization of the thermosetting electrolyte composition. [22] In addition, the present invention is to provide a lithium secondary battery including the gel polymer electrolyte. Means of solving the task [23] In one embodiment of the present invention, [24] LiPF 6 as the first lithium salt , [25] Non-aqueous organic solvent and [26] It includes a polymer or oligomer containing a unit represented by the following formula (1), [27] The polymer or oligomer including the unit represented by Formula 1 provides a thermosetting electrolyte composition for a lithium secondary battery contained in an amount of 0.6% to 15% by weight based on the total weight of the thermosetting electrolyte composition for a lithium secondary battery. [28] [Formula 1] [29] [30] In Formula 1, [31] R is a substituted or unsubstituted C 1 to C 5 alkylene group, [32] R 1 is -OH or, wherein R'is a substituted or unsubstituted alkylene group having 1 to 2 carbon atoms, R'' is hydrogen, -OH, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, b Is an integer of 0 or 1, [33] R 2 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms or a substituted or unsubstituted alkenylene group having 2 to 5 carbon atoms, [34] R 3 is a substituted or unsubstituted cycloalkyl group containing a ketone group having 3 to 10 carbon atoms or a substituted or unsubstituted heterocycloalkyl group containing a ketone group having 2 to 10 carbon atoms, [35] a is an integer of 0 or 1, [36] K, m and n are the number of repeating units, [37] k is an integer from 1 to 7,000, [38] m is an integer from 0 to 2000, [39] n is an integer from 0 to 600, [40] In this case, m and n are not 0 at the same time. [41] [42] In addition, in Formula 1, R is an unsubstituted C1-C3 alkylene group, [43] R 1 is -OH or, wherein R'is an unsubstituted C1-C2 alkylene group, R'' is hydrogen, -OH, or an unsubstituted C1-C2 alkyl group, and b is 0 or 1 Is an integer of any one, [44] R 2 is a substituted or unsubstituted alkenylene group having 2 to 5 carbon atoms, [45] R 3 may be a substituted or unsubstituted C 2 to C 6 heterocycloalkyl group containing a ketone group. [46] [47] Specifically, the unit represented by Formula 1 may be selected from the group consisting of units represented by the following Formulas 1a to 1h. [48] [Formula 1a] [49] [50] In Formula 1a, [51] K1, m1 and n1 are the number of repeating units, [52] k1 is an integer from 1 to 7,000, [53] m1 is an integer from 0 to 2,000, [54] n1 is an integer from 0 to 600, [55] At this time, m1 and n1 are not 0 at the same time. [56] [57] [Formula 1b] [58] [59] In Formula 1b, [60] k2, m2 and n2 are the number of repeat units, [61] k2 is an integer from 1 to 7,000, [62] m2 is an integer from 0 to 2,000, [63] n2 is an integer from 0 to 600, [64] At this time, m2 and n2 are not 0 at the same time. [65] [66] [Formula 1c] [67] [68] In Formula 1c, [69] k3, m3 and n3 are the number of repeat units, [70] k3 is an integer from 1 to 7,000, [71] m3 is an integer from 0 to 2,000, [72] n3 is an integer from 0 to 600, [73] At this time, m3 and n3 are not 0 at the same time. [74] [75] [Formula 1d] [76] [77] In Formula 1d, [78] k4, m4 and n4 are the number of repeat units, [79] k4 is an integer from 1 to 7,000, [80] m4 is an integer from 0 to 2,000, [81] n4 is an integer from 0 to 600, [82] At this time, m4 and n4 are not 0 at the same time. [83] [84] [Formula 1e] [85] [86] In Formula 1e, [87] k5, m5 and n5 are the number of repeating units, [88] k5 is an integer from 1 to 7,000, [89] m5 is an integer from 0 to 2,000, [90] n5 is an integer from 0 to 600, [91] At this time, m5 and n5 are not 0 at the same time. [92] [93] [Formula 1f] [94] [95] In Formula 1f, [96] k6, m6 and n6 are the number of repeat units, [97] k6 is an integer from 1 to 7,000, [98] m6 is an integer from 0 to 2,000, [99] n6 is an integer from 0 to 600, [100] At this time, m6 and n6 are not 0 at the same time. [101] [102] [Formula 1g] [103] [104] In Formula 1g, [105] k7, m7 and n7 are the number of repeating units, [106] k7 is an integer from 1 to 7,000, [107] m7 is an integer from 0 to 2,000, [108] n7 is an integer from 0 to 600, [109] At this time, m7 and n7 are not 0 at the same time. [110] [111] [Formula 1h] [112] [113] In Formula 1h, [114] k8, m8 and n8 are the number of repeat units, [115] k8 is an integer from 1 to 7,000, [116] m8 is an integer from 0 to 2,000, [117] n8 is an integer from 0 to 600, [118] At this time, m8 and n8 are not 0 at the same time. [119] [120] More specifically, the unit represented by Formula 1 may be a unit represented by Formula 1a. [121] [122] In addition, the polymer or oligomer including the unit represented by Formula 1 may be included in an amount of 1% to 15% by weight based on the total weight of the thermosetting electrolyte composition for a lithium secondary battery. [123] [124] Further, the lithium secondary battery electrolyte thermosetting composition LiPF 6 a may further include a second lithium salt other than. [125] The second lithium salt is Li cation + a, and the anion include F - , Cl - , Br - , I - , NO 3 - , N (CN) 2 - , ClO 4 - , BF 4 - , AlO 4 - , AlCl 4 - , SbF 6 - , AsF 6 - , BF 2 C 2 O 4 - , BC 4 O 8 - ,PO 2 F 2 - , PF 4 C 2 O 4 - , PF 2 C 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 3 SO 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 - it can include at least one selected from the group consisting of, specifically, Li (FSO 2 ) 2 may be a N. [126] [127] In addition, an embodiment of the present invention provides a gel polymer electrolyte for a lithium secondary battery prepared by thermally polymerizing the thermosetting electrolyte composition for a lithium secondary battery of the present invention. [128] [129] In addition, an embodiment of the present invention provides a lithium secondary battery including the gel polymer electrolyte of the present invention. Effects of the Invention [130] According to the present invention, it is possible to provide a thermosetting electrolyte composition for a lithium secondary battery capable of preventing pre-gelation at room temperature by including a polymer or oligomer containing a cyano group capable of polymerization by heat instead of not including a polymerization initiator. . In addition, it is possible to manufacture a gel polymer electrolyte with improved wettability and a high-performance lithium secondary battery with improved high-temperature stability by using the same. Best mode for carrying out the invention [131] Hereinafter, the present invention will be described in more detail. [132] The terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention based on the principle that there is. [133] [134] Thermosetting electrolyte composition for lithium secondary battery [135] Specifically, in one embodiment of the present invention [136] LiPF 6 as the first lithium salt , [137] Non-aqueous organic solvent and [138] It includes a polymer or oligomer containing a unit represented by the following formula (1), [139] The polymer or oligomer including the unit represented by Formula 1 provides a thermosetting electrolyte composition for a lithium secondary battery contained in an amount of 0.6% to 15% by weight based on the total weight of the thermosetting electrolyte composition for a lithium secondary battery. [140] [Formula 1] [141] [142] In Formula 1, [143] R is a substituted or unsubstituted C 1 to C 5 alkylene group, [144] R 1 is -OH or, wherein R'is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, R'' is hydrogen, -OH, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, b Is an integer of 0 or 1, [145] R 2 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms or a substituted or unsubstituted alkenylene group having 2 to 5 carbon atoms, [146] R 3 is a substituted or unsubstituted cycloalkyl group containing a ketone group having 3 to 10 carbon atoms or a substituted or unsubstituted heterocycloalkyl group containing a ketone group having 2 to 10 carbon atoms, [147] a is an integer of 0 or 1, [148] K, m and n are the number of repeating units, [149] k is an integer from 1 to 7,000, [150] m is an integer from 0 to 2000, [151] n is an integer from 0 to 600, [152] In this case, m and n are not 0 at the same time. [153] [154] (1) first lithium salt [155] First, the thermosetting electrolyte composition for a lithium secondary battery of the present invention includes LiPF 6 as a first lithium salt . [156] The first lithium salt, LiPF 6, is pyrolyzed by heat during the curing process for gelation to generate PF 5 , and the generated PF 5 may serve as a polymerization initiator. That is, by PF 5 generated by heat , a cyano group, a substituent contained in the compound represented by Formula 1, causes cationic polymerization to form a cross-link between the units represented by Formula 1 While curing, gelation may occur. [157] The first lithium salt, LiPF 6 , may be contained in a concentration of 0.2M to 2M, specifically 0.5M to 1.5M. If the concentration of the electrolyte salt exceeds 2M, the viscosity of the electrolyte for a lithium secondary battery may increase excessively, so that the electrolyte wettability may decrease, and the film formation effect may decrease. When the concentration of the lithium salt is less than 0.2M, the effect of the gelling reaction decreases, and thus the mechanical strength of the gel polymer electrolyte cannot be sufficiently secured. [158] [159] (2) organic solvent [160] In addition, the thermosetting electrolyte composition of the present invention contains a non-aqueous organic solvent. [161] The non-aqueous organic solvent is not limited as long as it can minimize decomposition due to an oxidation reaction or the like in the charging/discharging process of a secondary battery, and can exhibit desired properties together with an additive. [162] The organic solvent may include at least one organic solvent selected from the group consisting of a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, a linear ester-based organic solvent, and a cyclic ester-based organic solvent. [163] Specifically, the organic solvent may include a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent. [164] Specific examples of the cyclic carbonate-based organic solvent include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3- Any one selected from the group consisting of pentylene carbonate and vinylene carbonate, or a mixture of two or more of them may be exemplified, and among them, as an organic solvent of high viscosity, it includes ethylene carbonate that has high dielectric constant and thus dissociates lithium salt in the electrolyte well. I can. [165] In addition, the linear carbonate-based organic solvent is an organic solvent having a low viscosity and a low dielectric constant, and representative examples thereof are dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethylmethyl carbonate ( EMC), methylpropyl carbonate, and may include at least one selected from the group consisting of ethylpropyl carbonate. [166] In addition, the organic solvent may further include a linear ester-based organic solvent and/or a cyclic ester-based organic solvent in order to prepare a thermosetting electrolyte composition having a high electrical conductivity. [167] Such a linear ester-based organic solvent may include at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate as specific examples. have. [168] In addition, the cyclic ester-based organic solvent may include at least one selected from the group consisting of γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone, and ε-caprolactone. . [169] In addition, the organic solvent may be used by adding an organic solvent commonly used when preparing an electrolyte solution without limitation, if necessary. For example, it may further include at least one organic solvent of an ether-based organic solvent and a nitrile-based organic solvent. [170] The ether-based organic solvent may include any one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methylpropyl ether, and ethylpropyl ether. [171] The nitrile-based organic solvent is, for example, acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanenitrile, cyclopentane carbonitrile, cyclohexane carbonitrile, 2-fluorobenzonitrile, 4 -It may contain any one selected from the group consisting of fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile. . [172] [173] (3) Polymer or oligomer containing a unit represented by Formula 1 [174] In addition, the thermosetting electrolyte composition for a lithium secondary battery of the present invention includes a polymer or oligomer comprising a unit represented by the following formula (1) having a reaction site capable of thermal polymerization in the absence of a polymerization initiator. [175] [Formula 1] [176] [177] In Formula 1, [178] R is a substituted or unsubstituted C 1 to C 5 alkylene group, [179] R 1 is -OH or, wherein R'is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, R'' is hydrogen, -OH, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, b Is an integer of 0 or 1, [180] R 2 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms or a substituted or unsubstituted alkenylene group having 2 to 5 carbon atoms, [181] R 3 is a substituted or unsubstituted cycloalkyl group containing a ketone group having 3 to 10 carbon atoms or a substituted or unsubstituted heterocycloalkyl group containing a ketone group having 2 to 10 carbon atoms, [182] a is an integer of 0 or 1, [183] K, m and n are the number of repeating units, [184] k is an integer from 1 to 7,000, [185] m is an integer from 0 to 2000, [186] n is an integer from 0 to 600, [187] In this case, m and n are not 0 at the same time. [188] [189] Specifically, in Formula 1, R is an unsubstituted C1 to C3 alkylene group, [190] R 1 is -OH or, wherein R'is an unsubstituted C1-C2 alkylene group, R'' is hydrogen, -OH, or an unsubstituted C1-C2 alkyl group, and b is 0 or 1 Is an integer of any one, [191] R 2 is a substituted or unsubstituted alkenylene group having 2 to 5 carbon atoms, [192] R 3 may be a substituted or unsubstituted C 2 to C 6 heterocycloalkyl group containing a ketone group. [193] [194] In addition, in Formula 1, the molar ratio of the repeating unit k: the repeating unit (m+n) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k: the repeating unit (m+n) is 75 :25 to 90:10. [195] If the molar ratio of the repeating unit (m+n) to the repeating unit k is less than 1, the crosslinking reaction rate for gelation is lowered, making it difficult to form a stable gel polymer electrolyte.Therefore, the adhesion between the electrode and the separator decreases, resulting in thermal The effect of improving stability against mechanical and electrical shock may be insignificant. [196] In addition, when the molar ratio of the repeating unit (m+n) to the repeating unit k exceeds 30, side reactions are caused due to the increase in hygroscopicity, making it difficult to control the gelation reaction rate, and gelation occurs before sufficiently wetting inside the cell. Problems arise. [197] That is, since the polymer or oligomer containing the unit represented by Chemical Formula 1 contains a cyano group (CN) and a hydroxyl group (OH-) in its structure, it can be used at room temperature (25°C±10°C) without a separate polymerization initiator. ℃), for example, at a temperature of 40°C or higher, specifically 60°C or higher, to cause crosslinking polymerization reaction by anions, for example PF 6 - , generated from Li salts present in the thermosetting electrolyte composition, resulting in gelation. By such cross-linking, it is possible to prepare a gel polymer electrolyte including a polymer matrix that is stable at high temperatures and maintains strong adhesion to the positive electrode. As a result, the diffusion of metals such as Ni and Co Mn eluted from the positive electrode during high temperature storage is suppressed to suppress the loss of the active material, effectively control the generation of lithium polysulfide during charge/discharge, or O 2 or O radicals move to the electrolyte to inhibit a direct side reaction with the electrolyte, thereby preventing thermal runaway. Moreover, the prepared gel polymer electrolyte increases the adhesion between the electrode and the separator, thereby preventing the separator from shrinking when exposed to high temperature, thereby improving the thermal stability of the secondary battery even in a high temperature storage environment such as a hot box test. The effect can be implemented. [198] [199] More specifically, the unit represented by Formula 1 may be selected from the group consisting of units represented by the following Formulas 1a to 1h. [200] [Formula 1a] [201] [202] In Formula 1a, [203] K1, m1 and n1 are the number of repeating units, [204] k1 is an integer from 1 to 7,000, [205] m1 is an integer from 0 to 2,000, [206] n1 is an integer from 0 to 600, [207] At this time, m1 and n1 are not 0 at the same time. [208] Specifically, in Formula 1a, the molar ratio of the repeating unit k1: (m1+n1) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k1: the repeating unit (m1+n1) is 75:25 To 90:10. [209] [210] [Formula 1b] [211] [212] In Formula 1b, [213] k2, m2 and n2 are the number of repeat units, [214] k2 is an integer from 1 to 7,000, [215] m2 is an integer from 0 to 2,000, [216] n2 is an integer from 0 to 600, [217] At this time, m2 and n2 are not 0 at the same time. [218] Specifically, in Formula 1b, the molar ratio of the repeating unit k2: (m2+n2) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k2: the repeating unit (m2+n2) is 75:25 To 90:10. [219] [220] [Formula 1c] [221] [222] In Formula 1c, [223] k3, m3 and n3 are the number of repeat units, [224] k3 is an integer from 1 to 7,000, [225] m3 is an integer from 0 to 2,000, [226] n3 is an integer from 0 to 600, [227] At this time, m3 and n3 are not 0 at the same time. [228] Specifically, in Formula 1c, the molar ratio of the repeating unit k3: (m3+n3) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k3: the repeating unit (m3+n3) is 75:25 To 90:10. [229] [230] [Formula 1d] [231] [232] In Formula 1d, [233] k4, m4 and n4 are the number of repeat units, [234] k4 is an integer from 1 to 7,000, [235] m4 is an integer from 0 to 2,000, [236] n4 is an integer from 0 to 600, [237] At this time, m4 and n4 are not 0 at the same time. [238] Specifically, in Formula 1d, the molar ratio of the repeating unit k4: (m4+n4) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k4: the repeating unit (m4+n4) is 75:25 To 90:10. [239] [240] [Formula 1e] [241] [242] In Formula 1e, [243] k5, m5 and n5 are the number of repeating units, [244] k5 is an integer from 1 to 7,000, [245] m5 is an integer from 0 to 2,000, [246] n5 is an integer from 0 to 600, [247] At this time, m5 and n5 are not 0 at the same time. [248] Specifically, in Formula 1e, the molar ratio of the repeating unit k5: (m5+n5) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k5: the repeating unit (m5+n5) is 75:25 To 90:10. [249] [250] [Formula 1f] [251] [252] In Formula 1f, [253] k6, m6 and n6 are the number of repeat units, [254] k6 is an integer from 1 to 7,000, [255] m6 is an integer from 0 to 2,000, [256] n6 is an integer from 0 to 600, [257] At this time, m6 and n6 are not 0 at the same time. [258] Specifically, in Formula 1f, the molar ratio of the repeating unit k6: (m6+n6) is 70:30 to 99:1, and more specifically, the molar ratio of the repeating unit k6: repeating unit (m6+n6) is 75:25 To 90:10. [259] [260] [Formula 1g] [261] [262] In Formula 1g, [263] k7, m7 and n7 are the number of repeating units, [264] k7 is an integer from 1 to 7,000, [265] m7 is an integer from 0 to 2,000, [266] n7 is an integer from 0 to 600, [267] At this time, m7 and n7 are not 0 at the same time. [268] Specifically, in Formula 1g, the molar ratio of the repeating unit k7: (m7+n7) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k7: the repeating unit (m7+n7) is 75:25 To 90:10. [269] [270] [Formula 1h] [271] [272] In Formula 1h, [273] k8, m8 and n8 are the number of repeat units, [274] k8 is an integer from 1 to 7,000, [275] m8 is an integer from 0 to 2,000, [276] n8 is an integer from 0 to 600, [277] At this time, m8 and n8 are not 0 at the same time. [278] Specifically, in Formula 1h, the molar ratio of the repeating unit k8: (m8+n8) is 70:30 to 99:1, more specifically, the molar ratio of the repeating unit k8: the repeating unit (m8+n8) is 75:25 To 90:10. [279] [280] More specifically, the unit represented by Formula 1 may be a unit represented by Formula 1a. [281] [282] On the other hand, the polymer or oligomer containing the unit represented by Formula 1 is 0.6% to 15% by weight, specifically 1% to 15% by weight, more specifically based on the total electrolyte weight of the thermosetting electrolyte composition for a lithium secondary battery. It may be included in 1% to 10% by weight, more specifically 1% to 7% by weight. [283] When the content of the polymer or oligomer containing the unit represented by Formula 1 is 0.6% by weight or more, adhesion between the electrode and the separator is improved, and a gel polymer electrolyte capable of securing sufficient mechanical strength can be prepared. In addition, if the content of the polymer or oligomer containing the unit represented by Formula 1 is 15% by weight or less, specifically 10% by weight or less, disadvantages such as increase in resistance and decrease in ionic conductivity due to excessive amounts of polymers or oligomers can be prevented. In addition, it is possible to improve the wetting properties of the electrolyte composition. [284] If the content of the polymer or oligomer containing the unit represented by Formula 1 is less than 0.6% by weight, the gel-forming effect is lowered and a stable gel polymer electrolyte cannot be prepared.If it exceeds 15% by weight, an excessive amount of polymer or oligomer While not being dissolved in the non-aqueous organic solvent and remaining, it may be difficult to manufacture a gel polymer electrolyte having a desired performance as the resistance increases, making it impossible to drive the battery. [285] [286] On the other hand, the polymer or oligomer containing the unit represented by Formula 1 is a crosslinked polymer or oligomer having a weight average molecular weight (Mw) of 500,000 or less capable of forming gelation in a thermal polymerization reaction at a temperature of 60°C or higher, wherein the weight average Molecular weight can be controlled by the number of repeating units. Specifically, the weight average molecular weight of the polymer or oligomer may be 5,000 to 500,000, specifically 5,000 to 380,000, and when the weight average molecular weight of the polymer is within the above range, it is possible to effectively improve the mechanical strength of a battery including the polymer or oligomer. In addition, the stability improvement effect is excellent, and the effect of wetting properties of the thermosetting electrolyte composition can be realized. That is, when the weight average molecular weight of the polymer or oligomer containing the unit represented by Formula 1 is 500,000, specifically 380,000 or less, the effect of improving the impregnation of the thermosetting electrolyte composition into the electrode pores and the separator pores can be realized. [287] In this case, the weight average molecular weight of the polymer or oligomer may refer to a value in terms of standard polystyrene measured by GPC (Gel Permeation Chromatography), and unless otherwise specified, the molecular weight may refer to the weight average molecular weight. have. 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. [288] In addition, the viscosity (DMF, 20%, 25°C) of the polymer or oligomer including the unit represented by Formula 1 may be adjusted by the number of repeating units, and specifically, the unit including the unit represented by Formula 1 The viscosity of the polymer or oligomer may be 130 cPs to 160 cPs, more specifically 135 cPs to 155 cPs. [289] When the viscosity of the polymer or oligomer containing the unit represented by Formula 1 is within the above range, it is easy to secure the impregnation property of the thermosetting electrolyte composition. That is, when the viscosity of the polymer or oligomer containing the unit represented by Formula 1 is 130 cPs or more, the effect of limiting the movement of the sulfide-based compound can be implemented, and when the viscosity is 160 cPs or less, the impregnation of the thermosetting electrolyte composition over a certain range. Can be secured. [290] The viscosity is obtained by dissolving a polymer or oligomer containing a unit represented by Formula 1 in DMF (dimethyl formamide) at a concentration of 20%, and then using Brookfield's LV DV-II + Pro Viscometer (cone-plate type) at 25°C. The measurement was performed, and the spindle was S40, rpm 15, and the sample loading amount was 1mL. [291] [292] Specifically, since the polymer or oligomer containing the unit represented by Formula 1 contains a cyano group (-CN) as a terminal group in the structure, irreversible crosslinking reaction due to heat may be caused in the battery without a polymerization initiator. . [293] That is, when PF 5 is generated from LiPF 6 , which is the first lithium salt present in the thermosetting electrolyte composition by heat , it reacts with H 2 O remaining in the thermosetting electrolyte composition to produce H + (PF 5 OH) - . Then, the H + (PF 5 OH) - has the formula in combination with a first polymer or a cyano group (-CN) of the oligomer containing a unit represented by = C HN + (PF 5 OH) - , form a, and which also It forms a crosslinking bond with a cyano group (-CN) of a polymer or oligomer containing a unit represented by one formula (1). As a result, even if a separate polymerization initiator is not included, a polymerization reaction due to heat may be caused and gelation may occur. Therefore, it is possible to effectively prevent the pregelation reaction caused by the polymerization initiator when preparing the conventional gel polymer electrolyte. [294] Moreover, in the case of a gel polymer electrolyte containing a general polymerization initiator, a small amount of N 2 gas is generated from the polymerization initiator while the polymerization initiator generates radicals, and the gas thus generated remains inside the gel polymer electrolyte to prevent the formation of a non-uniform film. Cause. Therefore, it is possible to increase the interfacial resistance and to precipitate lithium dendrite. In addition, since the polymerization initiator remaining after radicals are generated from the polymerization initiator remains in the polymer matrix inside the gel polymer electrolyte after the reaction, it may cause an increase in resistance. [295] On the other hand, since the polymer or oligomer represented by Formula 1 used in the present invention does not require a polymerization initiator during the gelation reaction, problems such as generation of N 2 gas and increase in resistance due to the remaining polymerization initiator can be improved. In particular, when a gel polymer electrolyte containing a polymer or oligomer represented by Formula 1 is applied to a secondary battery equipped with a Ni-rich positive electrode, a polymer matrix that maintains strong adhesion between the gel polymer electrolyte and the positive electrode when exposed to high temperatures is formed. Therefore, when exposed to high temperatures, O 2 or O radicals generated due to collapse of the anode structure move to the electrolyte and prevent direct side reactions with the electrolyte, thereby reducing the amount of heat generated and leading to thermal runaway. Therefore, it is possible to further improve the high temperature stability of the secondary battery including the Ni rich anode. [296] [297] (4) second lithium salt [298] Meanwhile, the thermosetting electrolyte composition for a lithium secondary battery of the present invention may consume Li + ions while part of the first lithium salt, LiPF 6 , participates in the polymerization reaction during the gelation reaction . Thus, in the present invention, the Li in the lithium secondary battery electrolyte composition thermosetting + LiPF order to prevent the ion consumption 6 a may include a second lithium salt other than together. [299] The second lithium salt is a compound that can provide a lithium ion can be used without particular limitation, as the representative example the cation Li which is used in the lithium secondary battery + as an anion contains, F - , Cl - , Br - , I - , NO 3 - , N (CN) 2 - , ClO 4 - , BF 4 - , AlO 4 - , AlCl 4 - , SbF 6 - , AsF 6 - , BF 2 C 2 O 4 - , BC 4O 8 - , PO 2 F 2 - , PF 4 C 2 O 4 - , PF 2 C 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 - , 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 - consisting of At least one selected from the group may be included, and specifically, the second lithium salt may be lithium bisfluorosulfonylimide (Li(FSO 2 ) 2 N). [300] The molar ratio of the first lithium salt: the second lithium salt may be 1:9 to 9:1. [301] When the molar ratio of the first lithium salt and the second lithium salt is included in the above range, a safe output improvement effect of the lithium secondary battery may be realized. In this case, if the molar ratio of the second lithium salt to the first lithium salt exceeds 9, corrosion of the electrode current collector may be caused during charging and discharging, thereby deteriorating the high temperature stability of the secondary battery. [302] [303] Gel polymer electrolyte [304] In addition, in an embodiment of the present invention [305] It is possible to provide a gel polymer electrolyte for a lithium secondary battery formed by thermally polymerizing the thermosetting electrolyte composition for a lithium secondary battery in an inert atmosphere. [306] Specifically, the gel polymer electrolyte may be prepared by injecting the thermosetting electrolyte composition into a secondary battery and then curing it by a thermal polymerization reaction. [307] The thermal polymerization reaction takes about 2 minutes to 48 hours, and may be carried out at 60°C to 100°C, specifically 60°C to 80°C. [308] [309] Lithium secondary battery [310] In addition, in an embodiment of the present invention [311] It is possible to provide a lithium secondary battery including a negative electrode, a positive electrode, a separator interposed between the negative electrode and the positive electrode, and the gel polymer electrolyte for a lithium secondary battery of the present invention. [312] In the lithium secondary battery of the present invention, an electrode assembly comprising a positive electrode, a negative electrode, and a separator selectively interposed between the positive electrode and the negative electrode is sequentially stacked in a secondary battery case or an exterior material, and then the electrolyte composition for a lithium secondary battery is injected. And, it may be prepared by curing the infused electrolyte composition for a lithium secondary battery by thermal polymerization. [313] [314] Meanwhile, in the lithium secondary battery of the present invention, the positive electrode, the negative electrode, and the separator may be all those that have been manufactured and used by a conventional method when manufacturing a lithium secondary battery. [315] [316] (1) anode [317] 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. [318] 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. [319] The positive electrode active material is a compound capable of reversible intercalation and deintercalation of lithium, and specifically, may include a lithium composite metal oxide including lithium and at least one metal such as cobalt, manganese, nickel or aluminum. 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