Detailed description of the invention Technical challenge [21] The present invention is to solve the above problems, while improving the performance and safety of the battery by increasing the adhesion with the gel polymer electrolyte, it can be applied to a variety of battery types, a coating layer of a multilayer structure that is easy to manufacture It is to provide a separator for a lithium secondary battery and a lithium secondary battery including the same. [22] Means of solving the task [23] In one aspect, the present invention, the substrate; A first coating layer comprising a first organic binder containing an ethylenically unsaturated group; And a second coating layer comprising a second organic binder and inorganic particles. [24] In this case, the first coating layer may be formed on the surface of the substrate, and the second coating layer may be formed on the first coating layer. [25] Meanwhile, the second coating layer may be formed on the surface of the substrate, and the first coating layer may be formed on the second coating layer. [26] In another aspect, the present invention provides lithium comprising the step of forming a first coating layer including a first organic binder including an ethylenically unsaturated group on a surface of a substrate and a second coating layer including a second organic binder and inorganic particles. It provides a method for manufacturing a separator for a secondary battery. [27] In another aspect, the present invention provides at least one unit cell including at least one or more anodes, at least one or more cathodes, and at least one or more first separators interposed between the anode and the cathode; And a gel polymer electrolyte formed by polymerization of an electrode assembly including a second separator interposed between the unit cells, and an oligomer including a (meth)acrylate group, wherein the first separator and the second separator, A first coating layer containing a first organic binder containing an ethylenically unsaturated group and a second coating layer containing a second organic binder and inorganic particles, the first organic binder containing the ethylenically unsaturated group and the (meta) It provides a lithium secondary battery in which an oligomer including an acrylate group is polymerized to form a polymer network having a three-dimensional structure. [28] Effects of the Invention [29] The separator according to the present invention includes a first organic binder containing an ethylenically unsaturated group in the first coating layer, and the ethylenic unsaturated group and the oligomer contained in the gel polymer electrolyte composition react to improve adhesion between the separator and the gel polymer electrolyte. As a result, the performance and stability of the lithium secondary battery can be improved. [30] In addition, the separator according to the present invention, when a second coating layer including a second organic binder and inorganic particles is formed on the first coating layer, when manufacturing a lithium secondary battery manufactured through a high-temperature process such as a lamination process, ethylene It is possible to prevent the unsaturated group from being exposed to high temperatures, and when it is formed under the first coating layer, a battery can be manufactured under various conditions, and thus manufacturing processability can be improved when manufacturing a separator. [31] Therefore, not only can the durability of the separator be improved, but also it can be used as a separator for a lithium secondary battery having various structures, so that manufacturing processability of a lithium secondary battery can be improved. [32] Best mode for carrying out the invention [33] Hereinafter, the present invention will be described in more detail. [34] The terms or words used in the present 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 a meaning and concept consistent with the technical idea of ​​the present invention based on the principle that there is. [35] The 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. [36] In the present specification, terms such as "comprises", "includes" or "have" are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and 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. [37] In the present specification, the weight average molecular weight may mean a value in terms of standard polystyrene measured by GPC (Gel Permeation Chromatograph), and unless otherwise specified, the molecular weight may mean a weight average molecular weight. In this case, the weight average molecular weight may 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 weight average molecular weight is calculated according to the analysis method (system: Alliance 4, column: Ultrahydrogel linear x 2, eluent: 0.1M NaNO 3 ( pH 7.0 phosphate buffer, flow rate: 0.1 mL/min, temp: 40℃, injection: 100μL) [38] [39] [40] The separator for a lithium secondary battery according to the present invention includes a first coating layer including a first organic binder including an ethylenically unsaturated group, and a second coating layer including a second organic binder and inorganic particles. [41] [42] Conventionally, inorganic particles were coated on the surface of a substrate to improve durability and conductivity of the separator, but the inorganic particles and conventional binders have low bonding strength with the gel polymer electrolyte and can perform polymerization reactions. There is a problem that the adhesion with the electrolyte is significantly lowered because it cannot be used. If the adhesion between the electrolyte and the separator decreases, the safety of the battery may decrease, such as inducing a short circuit inside the battery. [43] Accordingly, the inventors of the present invention devised a separation membrane further forming a separate layer including a first organic binder containing an ethylenically unsaturated group in addition to the conventional inorganic particle coating layer. The ethylenically unsaturated group included in the first organic binder may undergo a radical polymerization reaction with an oligomer included in the composition for a gel polymer electrolyte. [44] More specifically, the composition for a gel polymer electrolyte may include an oligomer including a (meth)acrylate group, an amide group, an oxyalkylene group, a siloxane group, and the like, and the functional groups included in the oligomer are the first organic binder These are functional groups capable of radical polymerization reaction with ethylenic unsaturated groups contained in. Accordingly, the oligomer and the first organic binder may be bonded in a three-dimensional structure through a radical polymerization reaction in the curing process of the composition for a gel polymer electrolyte, and as a result, the adhesion between the separator and the gel polymer electrolyte may be improved. On the other hand, in the case of the present invention, not only the adhesion between the separator and the gel polymer electrolyte is improved by the first coating layer containing the first organic binder, but also the adhesion between the separator and the electrode by the second coating layer including the second organic binder. You can keep it constant. In addition, in the case of the separator for a lithium secondary battery according to the present invention, the stacking order of the first and second coating layers may be changed in consideration of the structure of the battery to be manufactured, the purpose of use, and the battery manufacturing process. [45] At this time, the thickness of the separation membrane may be 0.1 to 20 ㎛, preferably 0.5 to 20 ㎛, more preferably 1.0 to 20 ㎛. When the thickness of the separation membrane is formed to the thickness, the mechanical properties and high temperature durability of the separation membrane may be kept constant. [46] [47] As the substrate, a porous substrate may be used, and in general, the porous substrate may be used without particular limitation as long as it can be used as a separator material for an electrochemical device. Such porous substrates include, for example, polyolefin, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyether sulfone, polyphenylene oxide, A nonwoven fabric or a porous polymer film formed of at least one of polymer resins such as polyphenylene sulfide and polyethylene naphthalene, or a laminate of two or more of them, but is not particularly limited thereto. [48] [49] The first coating layer is for improving adhesion between the gel polymer electrolyte and the separator, and includes a first organic binder containing an ethylenically unsaturated group. The ethylenically unsaturated group is bonded to the oligomer contained in the composition for the gel polymer electrolyte through radical polymerization. [50] For example, the ethylenically unsaturated group may include at least one selected from the group consisting of a vinyl group, an acryloxy group, and a methacryloxy group. [51] Meanwhile, in the first organic binder, in addition to the functional groups, an alkylene group, an alkylene oxide group, and a halogen element (F, Cl, Br, I) in which at least one halogen element (F, Cl, Br, I) is substituted It may further include a unit including at least one or more selected from the group consisting of an alkylene oxide group, an imide group, and a celluloid. [52] At this time, in the case of the ethylenically unsaturated group, it may be located at the end portion of the polymer main chain composed of the units or the side portion of the polymer main chain, and the number or position of the attached functional groups is not specified. [53] For example, the unit including an alkylene group in which at least one halogen element is substituted may be represented by at least one selected from units represented by the following Chemical Formulas X-1 to X-6. [54] [Formula X-1] [55] [56] In Formula X-1, m1 is an integer ranging from 1 to 100. [57] [Formula X-2] [58] [59] In Formula X-2, m2 and m3 are each independently an integer of 1 to 100. [60] For example, a unit containing an alkylene oxide group may be represented by the following Formula X-3. [61] [Formula X-3] [62] [63] In Formula X-3, m4 is an integer ranging from 1 to 100. [64] For example, a unit containing an alkylene oxide group in which the halogen element is substituted may be represented by Formula X-4 below. [65] [Formula X-4] [66] [67] In Formula X-4, m5 is an integer ranging from 1 to 100. [68] For example, the unit containing the imide group may be represented by the following Formula X-5. [69] [Formula X-5] [70] [71] In Formula X-5, m6 is an integer of 1 to 100. [72] For example, the celluloid-containing unit may be represented by Formula X-6 below. [73] [Formula X-6] [74] [75] In Formula X-6, m7 is an integer of 1 to 100. [76] Specifically, the compound used as the first organic binder is an ethylenic unsaturated group substituted at the end or side portion of the polymer main chain including at least one unit selected from the group consisting of Formulas X-1 to X-6. It is a compound. [77] For example, in the case of a polymer or copolymer containing units represented by Formulas X-1 to X-6, it is generally formed by a free radical reaction or the like. At this time, at the end of the polymerization reaction, end-capping is performed to prevent further polymerization from occurring at the end or side of the main chain of the polymer or copolymer. An oxide group and an alkyl group are attached. [78] For example, in the case of treating the end with a functional group containing a halogen element, a halogenated compound such as sodium chloride (NaCl) may be used as an end-capping agent, but limited to the above method Also, the type of the end capping agent is not limited to the above material. [79] For example, when a halogen element or the like is located at the end or side portion, when reacted with a (meth)acrylate compound or a vinyl compound, the halogen element at the end portion is a (meth)acryloxy group or a vinyl group. Likewise, it is substituted with an ethylenically unsaturated group. Through the above reaction, a first organic binder having an ethylenically unsaturated group may be prepared. [80] [81] The first organic binder may be used alone for the first coating layer, or 1 to 80 parts by weight, preferably 5 to 60 parts by weight, more preferably 5 parts by weight, based on 100 parts by weight of the first coating layer. It may be included in parts by weight to 40 parts by weight. When the first organic binder is included within the above range, the bonding strength with the gel polymer electrolyte may be maintained above a certain level. [82] Meanwhile, the first coating layer may further include the inorganic particles in addition to the first organic binder, and the content may be included in the balance of the first coating layer excluding the first organic binder. The inorganic particles will be described in more detail below. [83] [84] The second coating layer is formed directly on the surface of the substrate in order to enhance the durability of the separator substrate and improve processability according to the stacking order, or is formed on the first coating layer when subjected to a lamination process, etc. It is for preventing exposure to this high temperature, and includes a second organic binder and inorganic particles. [85] [86] The second organic binder is used to fix the inorganic particles. [87] As the second organic binder, a conventional binder may be used. More specifically, the second organic binder is an alkylene group in which at least one halogen element (F, Cl, Br, I) is substituted, an alkylene oxide group, an alkyl substituted with a halogen element (F, Cl, Br, I) It may include a polymer including a unit containing at least one or more selected from the group consisting of a ren oxide group, an imide group, and a celluloid. [88] For example, the second organic binder may include a polymer including at least one unit selected from the group consisting of Formulas X-1 to X-6, and the above Formulas X-1 to X-6 As described above, description is omitted. [89] [90] For example, the second organic binder may include polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HEP), polyvinylidenefluoride, etc., but limited to the above types. It does not become. [91] Meanwhile, as the second organic binder, polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethylcellulose (polyacrylonitrile), polymethylmethacrylate, polyvinyl alcohol, carboxymethylcellulose ( CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), various copolymers including fluorine rubber, and the like may be used. [92] The second organic binder may be included in an amount of 1 to 80 parts by weight, preferably 5 to 60 parts by weight, more preferably 5 to 40 parts by weight, based on 100 parts by weight of the second coating layer. When the second organic binder is included within the above range, detachment of inorganic particles may be prevented, and adhesion and mechanical performance may also be maintained above a certain level. [93] The inorganic particles form an interstitial volume between the particles to form microscopic pores and at the same time serve as a type of spacer capable of maintaining a physical shape. In addition, since the inorganic particles can transfer and move lithium ions, lithium ion conductivity can be improved. At this time, by adjusting the size of the inorganic particles, the content of the inorganic particles, and the composition of the inorganic particles and the polymer, microscopic pores can be formed, and the pore size and porosity can be controlled. [94] The inorganic particles may include inorganic particles commonly used in the art. For example, the inorganic particles may include at least one element selected from the group consisting of Si, Al, Ti, Zr, Sn, Ce, Mg, Ca, Zn, Y, Pb, Ba, Hf, and Sr. And, preferably, it may include at least one element selected from the group consisting of Si, Al, Ti, and Zr. [95] More specifically, the inorganic particles are SiO 2 , Al 2 O 3 , TiO 2 , ZrO 2 , SnO 2 , CeO 2 , MgO, CaO, ZnO, Y 2 O 3 , 　Pb(Zr,Ti)O 3　(PZT) , Pb (1-a1) La a1 Zr (1-b1) Ti b1 O 3　(0≤a1≤1, 0≤b1≤1, PLZT), PB(Mg 3 Nb 2/3 )O 3 -PbTiO 3　 ( PMN-PT), BaTiO 3, HfO 2 (hafnia), SrTiO 3　 and the like, and the inorganic materials listed above generally have properties that do not change their physical properties even at a high temperature of 200°C or higher. More preferably, the inorganic particles may include at least one inorganic material selected from the group consisting of SiO 2 , Al 2 O 3 , TiO 2 and ZrO 2 . [96] The inorganic particles may be included in the balance excluding the second organic binder based on 100 parts by weight of the second coating layer. [97] [98] [99] Next, a method of manufacturing a separator for a lithium secondary battery according to the present invention will be described. The separator for a lithium secondary battery according to the present invention is manufactured by forming a first coating layer including a first organic binder containing an ethylenically unsaturated group and a second coating layer including a second organic binder and inorganic particles on the surface of the substrate do. [100] For example, after forming the first coating layer on the substrate, a second coating layer may be formed on the first coating layer. For another example, after forming the second coating layer on the substrate, a first coating layer may be formed on the second coating layer. [101] Meanwhile, according to the order of formation of the first and second coating layers, a separator for a lithium secondary battery may be formed in which a substrate/first coating layer/second coating layer or a substrate/second coating layer/first coating layer are stacked in this order. The reason for the different stacking order has already been described, and thus description thereof will be omitted. [102] [103] The first coating layer may be formed under a temperature condition of 40°C to 110°C, preferably 50°C to 110°C, more preferably 60°C to 110°C. When the first coating layer is formed under the above temperature conditions, coating can be easily performed while minimizing damage to ethylenically unsaturated groups. [104] More specifically, to prepare a first coating layer composition comprising a first organic binder containing an ethylenically unsaturated group. In this case, an organic solvent or the like may be used as a solvent other than the first organic binder. For example, N-methylpyrrole, acetone, or the like may be used, but is not limited to the type of the solvent. The solvent may be included so that the content of the solid content including the first organic binder may be 10 parts by weight to 50 parts by weight, preferably 10 parts by weight to 40 parts by weight relative to the total 100 parts by weight of the first coating layer composition. When the solvent is included within the above range, it is easy to apply and processability may be improved. [105] [106] The second coating layer may be formed under a temperature condition of 120 ℃ to 200 ℃, preferably 120 ℃ to 190 ℃, more preferably, 120 ℃ to 180 ℃. When the second coating layer is formed under the temperature condition, damage to the separation membrane can be prevented, and the solvent used in the coating layer forming process can be effectively removed. [107] More specifically, to prepare a second coating layer composition comprising a second organic binder and inorganic particles. In this case, in addition to the second organic binder and inorganic particles, a solvent commonly used for coating a separator may be used as a solvent. For example, N-methylpyrrole or the like can be used. The solvent is included so that the content of the solid content including the second organic binder and inorganic particles may be 10 parts by weight to 50 parts by weight, preferably 10 parts by weight to 40 parts by weight based on the total 100 parts by weight of the second coating layer composition. I can. When a solvent is included within the above range, it is easy to apply and maintain fairness above a certain level. [108] [109] [110] Next, a lithium secondary battery according to the present invention will be described. A lithium secondary battery according to another embodiment of the present invention includes an electrode assembly and a gel polymer electrolyte. [111] More specifically, the electrode assembly includes at least one unit cell including at least one positive electrode, at least one negative electrode, at least one first separator interposed between the positive electrode and the negative electrode, and a second interposed between the unit cells. It includes a separator. In this case, the first separator and the second separator use the separator, and the details thereof are the same as those described above, and a detailed description thereof will be omitted. [112] The positive electrode may be prepared by coating a positive electrode active material slurry including a positive electrode active material, an electrode binder, a conductive material, and a solvent on the positive electrode current collector. [113] 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. [114] 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 containing 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-Y1 Mn Y1 O 2 (here, 0