Title of the invention: Separator without a description of the separator Technical field [One] This application claims the benefit of priority based on Korean Patent Application No. 2018-0055138 filed May 14, 2018, and all contents disclosed in the documents of the Korean patent application are incorporated as part of this specification. [2] The present invention relates to a separator without a separator substrate, and specifically, to a separator including a binder polymer that binds an inorganic substance and the inorganic substance without including a polyolefin resin substrate constituting the substrate of the separator. Background [3] As portable devices such as smart phones, notebook computers, tablet PCs, and portable game consoles have become lighter and more functional, demand for secondary batteries used as driving power sources is increasing. In the past, nickel-cadmium, nickel-hydrogen, and nickel-zinc batteries have been used, but lithium secondary batteries with high operating voltage and high energy density per unit weight are most often used. [4] 2.The demand for lithium secondary batteries is increasing in proportion to the growth of the portable device market. have. [5] A lithium secondary battery is a structure in which an electrode assembly capable of charging and discharging a positive electrode/separator/cathode structure is mounted on a battery case. The positive electrode and the negative electrode are manufactured by applying a slurry containing an electrode active material or the like to one or both surfaces of a metal current collector, and drying and rolling. [6] The separator is one of the important factors that determine the lifespan of a secondary battery, and requires ion permeability and mechanical strength to allow the electrolyte to pass smoothly while electrically insulating the anode and the cathode. As the application of high-energy lithium secondary batteries is expanded, the demand for safety at high temperatures of the separator is also increasing. [7] Conventionally, a separator made of a commonly used separator substrate and an inorganic coating layer does not have sufficient adhesive strength with an electrode due to its material properties, and thus there is a problem of being partially lifted or wrinkled at the interface depending on the manufacturing process. In addition, polyolefins generally used as separator substrates have problems in thermal stability, such as melting at high temperatures. [8] In order to solve such a problem, the polyolefin separator substrate was removed and the separator was constructed only with an inorganic coating layer.However, the insulation of the separator itself is significantly low, and when applied to an electrochemical device, it is vulnerable to internal short circuits, and due to low tensile strength or elongation There is a fatal disadvantage in that the separator is easily torn and a minute short circuit occurs inside the electrode assembly. [9] Patent Document 1 discloses a microporous polymer layer composed of organically modified aluminum boehmite and an organic polymer, but does not disclose a method such as polymerization for improving the strength thereof. [10] Patent Document 2 relates to an electrolyte for a lithium battery, and a negative electrode and a lithium battery including the same, and discloses an intermediate layer formed of an electrolyte and a solid electrolyte between the positive electrode and the negative electrode and serving as a separator. The electrolyte is interposed between the positive electrode and the negative electrode, or has a structure corresponding to the present invention in that it may include a separator, but differs from the present invention in that the surface-modified nanoparticle composite is dispersed in a block copolymer. . In addition, Patent Document 2 describes only the effect on the surface modification of the nanoparticles. [11] Non-Patent Literature 1 discloses crosslinking of PVdF-HFP/PEGDMA (polyethylene glycol dimethacrylate), but does not disclose that the material is applied to a separator, and applies only to a polymer electrolyte. [12] Non-Patent Document 2 discloses boehmite nanoparticles and polyvinylidene fluoride polymers as separators for lithium secondary batteries, but mentions that they are inadequate for application to a high-stress battery cell assembly process. [13] Non-Patent Document 3 discloses a porous ceramic membrane based on magnesium aluminate as a separator for a lithium secondary battery having flexibility and thermal stability, but does not disclose a method for improving strength. [14] As such, an effective technology for a separator without a polyolefin substrate that has high stability against a high temperature environment, has excellent insulating properties, improves tensile strength and elongation, has excellent electrolyte impregnation properties, and is capable of high ion transfer, has not yet been proposed. Did. [15] (Prior technical literature) [16] (Patent Document 0001) US Patent Publication No.8883354 [17] (Patent Document 0002) Republic of Korea Patent Publication No. 2016-0140211 [18] (Non-patent document 0001) Thermal shundown behavior of PVdF-HFP based polymer electrolytes comprising heat sensitive cross linkable oligomers, J. power Sources 144, 2005 [19] (Non-patent document 0002) Boehmite-based ceramic separator for lithium-ion batteries, Journal of Applied Electrochemisrty, 2016, 69 [20] (Non-patent document 0003) Thin, flexible and thermally stable ceramic membranes as separator for lithium-ion batteries, Journal of Membrane Science, 2014, 103 Detailed description of the invention Technical challenge [21] The present invention is to solve the above problems, and by using a separator having a structure that does not include a polyolefin substrate and includes an inorganic particle and a binder for bonding between the inorganic particles, while securing the insulation of a conventional separator, It has high stability against high-temperature environments, has excellent insulation properties, has excellent electrolyte impregnation properties, enables high ion transfer, and improves the tensile strength and elongation of the separator itself to prevent a short circuit due to damage to the separator. It is an object of the present invention to provide a separation membrane to which there is a technology and the technology is applied. Means of solving the task [22] The present invention for solving the above problems is a porous separator for an electrochemical device to secure electrical insulation between an anode and a cathode, [23] The separator does not contain a polyolefin substrate, [24] Prepared by mixing and coating a composition for a separator including inorganic particles, a polymer binder for bonding between the inorganic particles, and a crosslinking agent, drying, and crosslinking the crosslinking agent thereafter, [25] The content of the crosslinking agent in the composition for a separation membrane provides a porous separation membrane for an electrochemical device comprising more than 0% by weight to 5% by weight or less based on the total weight of the solid content. [26] At this time, the crosslinking agent may be represented by the following formula. [27] Formula 1 [28] [29] Formula 2 [30] [31] Formula 3 [32] [33] In Formulas 1 to 3, m is an integer of 1 to 100, n is an integer of 0 to 30, and o is an integer of 1 to 1,000. The weight average molecular weight of Formulas 1 to 3 is 1,000 to 100,000. [34] Formula 4 [35] [36] In Formula 4, m4 is an integer of 1 to 100, n4 is an integer of 0 to 30, and o4 is an integer of 1 to 1,000. The weight average molecular weight of Formula 4 is 1,000 to 100,000, and the p value is a variable dependent thereon. [37] Formula 5 [38] [39] In Formula 5, a and c are integers of 1 to 30, b is an integer of 1 to 1000, and a weight average molecular weight is 1,000 to 100,000. [40] The inorganic particles are high-k inorganic particles having a dielectric constant of 1 or more, inorganic particles having piezoelectricity, inorganic particles having lithium ion transfer ability, alumina hydrate, or a mixture of two or more thereof, preferably Al 2 O 3 , AlOOH, SiO 2 , MgO, TiO 2 and BaTiO 2 is one or more selected from the group consisting of. [41] The polymeric binder is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, polymethyl methacrylate, poly Acrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethylpolyvinyl alcohol, Cyanoethylcellulose, cyanoethyl sucrose, pullulan, carboxymethylcellulose, acrylonitrile styrene butadiene copolymer, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber (SBR), TFE, It is at least one selected from the group consisting of fluorine rubber and polyimide, and preferably at least one selected from the group consisting of PVdF, TFE, and polyimide. [42] The separator may further include an initiator and/or a reaction catalyst, and the reaction temperature of the crosslinking agent is 120°C to 160°C. [43] The initiator is an azo compound or a peroxide compound, specifically, the azo compound is 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis( Isobutyronitrile), at least one of 2,2'-azobis (2,4-dimethylvaleronitrile) and 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) Is selected, preferably 2,2'-azobis (isobutyronitrile). [44] The peroxide-based compounds are tetramethylbutylperoxy neodecanoate, bis(4-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxycarbonate, butylperoxy neodecanoate, dipropyl per Oxydicarbonate, diisopropyl peroxydicarbonate, diethoxyethyl peroxydicarbonate, diethoxyhexylperoxydicarbonate, hexyl peroxydicarbonate, dimethoxybutyl peroxydicarbonate, bis(3-methoxy-3) -Methoxybutyl) peroxy dicarbonate, dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl peroxy dicarbonate, 1,1,3,3-tetramethylbutyl per Oxypivalate, hexyl peroxy pivalate, butyl peroxy pivalate, trimethyl hexanoyl peroxide, dimethyl hydroxy butyl peroxy neo decanoate, amyl peroxy neo decanoate, Atofina, butyl peroxy neo Decanoate, t-butylperoxyneoheptanoate, amylperoxy pivalate, t-butylperoxy pivalate, t-amyl peroxy-2-ethylhexanoate, lauryl peroxide, dilauroyl At least one or more of (dilauroyl) peroxide, didecanoyl peroxide, benzoyl peroxide, or dibenzoyl peroxide is selected. [45] It is preferable that the thickness of the separator is 5 μm to 30 μm. [46] The content of the crosslinking agent in the separator is greater than 2% by weight to 20% by weight or less based on the total weight of the solid content, and the air permeability of the separator is 50sec/100cc to 4,000sec/100cc. [47] The present invention provides an electrochemical device comprising a porous separator for an electrochemical device according to the present invention. Mode for carrying out the invention [48] Hereinafter, the present invention will be described in detail. Prior to this, terms or words used in this specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriate the concept of terms to describe their own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of ​​the present invention on the basis of the principle that it can be defined. Therefore, the configurations presented in the embodiments described in the present specification are only the most preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention, and various equivalents that can replace them at the time of the present application It should be understood that there may be variations. [49] The present invention is a porous separator for an electrochemical device for securing electrical insulation between an anode and a cathode, [50] The separator does not contain a polyolefin substrate, [51] It provides a porous separator for an electrochemical device comprising inorganic particles, a polymer binder for bonding between the inorganic particles, and a crosslinking agent. [52] The separator of the present invention has a structure that does not have a substrate based on a polyolefin-based separator as compared to a conventional separator. That is, a conventional separator has a structure in which an inorganic material layer composed of an inorganic material and a binder is applied on one surface of a polyolefin-based separator substrate, whereas the present invention omits the conventional separator material and materials constituting the inorganic material layer directly form the separator. Make up. [53] On the other hand, as another conventional separator, a separator composed of only the inorganic material layer is highly likely to cause a short circuit due to damage to the separator interposed between the electrode assemblies as the overall strength of the separator is lowered because the polyolefin separator substrate is omitted. There is. [54] 1) crosslinking agent [55] The crosslinking agent may be represented by the following formula. [56] Formula 1 [57] [58] Formula 2 [59] [60] Formula 3 [61] [62] In Formulas 1 to 3, m is an integer of 1 to 100, n is an integer of 0 to 30, and o is an integer of 1 to 1,000. The weight average molecular weight of Formulas 1 to 3 is 1,000 to 100,000. [63] Formula 4 [64] [65] In Formula 4, m4 is an integer of 1 to 100, n4 is an integer of 0 to 30, and o4 is an integer of 1 to 1,000. The weight average molecular weight of Formula 4 is 1,000 to 100,000, and the p value is a variable dependent thereon. [66] Formula 5 [67] [68] In Formula 5, a and c are integers of 1 to 30, b is an integer of 1 to 1000, and a weight average molecular weight is 1,000 to 100,000. [69] The content of the crosslinking agent in the separation membrane is more than 2% by weight to 20% by weight or less, preferably more than 2% by weight and 10% by weight or less, more preferably more than 2% by weight and 8% by weight or less, based on the total weight of the solid content. More preferably more than 3% by weight and not more than 7% by weight, most preferably more than 4% by weight and not more than 6% by weight. [70] In the case where the content of the crosslinking agent in the separator is greater than the upper limit, crosslinking does not occur completely, and the crosslinking agent locally acts as a plasticizer, which is not preferable because the tensile strength decreases significantly. [71] If it exceeds 20% by weight, the inorganic material content is small, so the ionic conductivity is lowered, and mechanical properties such as thermal contraction of the film may be deteriorated. [72] In the present invention, the crosslinking agent reacts at a specific temperature to form a three-dimensional network structure, and as the density increases due to the characteristics of the network structure, physical properties related to stiffness are improved, and since it affects the movement of electrons, insulation resistance is increased. [73] The reaction temperature of the crosslinking agent may be in the range of 120°C to 160°C, more preferably in the range of 130°C to 150°C. At a low temperature before reaching the temperature range, the crosslinking agent having a linear structure, As the temperature range is reached, a reaction occurs and a three-dimensional network structure is formed by crosslinking. [74] When the reaction temperature of the crosslinking agent is lower than 120°C, the crosslinking reaction is difficult to occur because the crosslinking site of the crosslinking agent is not broken, and when it is higher than 160°C, the crosslinking agent may melt, which is not preferable. [75] In addition, the separator according to the present invention has a high breakdown voltage even if the separator substrate is omitted because a crosslinking agent is added to the separator composed of inorganic particles and a binder. [76] Specifically, when a foreign material such as iron (Fe), which is a conductive material, is applied to the separator of the present application, it is applied to a secondary battery for automobiles, and it is confirmed that it has a substantially similar dielectric breakdown voltage value when compared to a separator including a separator substrate. In addition, the dielectric breakdown voltage hardly decreases before and after the application of the conductive material. [77] 2) inorganic particles [78] Inorganic particles can also form micropores by enabling the formation of empty spaces between inorganic particles, and serve as a kind of spacer capable of maintaining physical shape. Does not have a characteristic. [79] These inorganic particles are not particularly limited as long as they are electrochemically stable, that is, the inorganic particles that can be used in the present invention are oxidized and/or in the operating voltage range of the applied battery (eg, 0-5V based on Li/Li+). Or it is not particularly limited as long as the reduction reaction does not occur. Particularly, in the case of using inorganic particles having a high electrolyte ion transfer ability, it is possible to improve the performance in the electrochemical device, and thus it is preferable that the electrolyte ion transfer ability is as high as possible. In addition, when the inorganic particles have a high density, it is difficult to disperse when the separator is formed, as well as a problem of increasing the weight when manufacturing a battery, so it is preferable that the density is as small as possible. In addition, in the case of an inorganic material having a high dielectric constant, the ionic conductivity of the electrolyte may be improved by contributing to an increase in the degree of dissociation of an electrolyte salt such as a lithium salt in the liquid electrolyte. [80] For the above reasons, the inorganic particles are high-k inorganic particles having a dielectric constant of 1 or more, preferably 10 or more, inorganic particles having piezoelectricity, inorganic particles having lithium ion transfer ability, alumina hydrate, or these It may be a mixture of two or more of. [81] Examples of inorganic particles having a dielectric constant of 1 or more include SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , SiC or a mixture thereof. However, it is not limited thereto. [82] The piezoelectricity inorganic particles are non-conductors at normal pressure, but when a certain pressure is applied, they refer to a material having physical properties that allow electricity to pass through changes in the internal structure, and exhibit high dielectric constant properties having a dielectric constant of 100 or more, as well as a constant pressure. When tensioned or compressed by applying, electric charges are generated, and one side is positively charged and the other side is negatively charged, thereby generating a potential difference between both sides. [83] In the case of using inorganic particles having the above characteristics, when an internal short circuit occurs between the two electrodes due to external impacts such as local crush, nail, etc. In addition, a potential difference in the particles occurs due to the piezoelectricity of the inorganic particles, and thus electron transfer between the two electrodes, that is, a fine current flow, can be achieved, thereby smoothly reducing the voltage of the battery and thus improving the safety. [84] Examples of the piezoelectric inorganic particles include BaTiO 3 , Pb(Zr,Ti)O 3 (PZT), Pb 1-x La x Zr 1-y Ti y O 3 (PLZT), Pb(Mg 1/3 Nb 2 /3 )O 3 -PbTiO 3 (PMN-PT) hafnia (HfO 2 ) or a mixture thereof, and the like, but is not limited thereto. [85] The inorganic particles having a lithium ion transfer ability refer to inorganic particles containing a lithium element but not storing lithium and having a function of moving lithium ions, and the inorganic particles having a lithium ion transfer ability exist inside the particle structure. Since lithium ions can be transferred and moved due to a kind of defect, the lithium ion conductivity in the battery is improved, and thus, battery performance can be improved. [86] Examples of the inorganic particles having the lithium ion transfer ability include lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li x Ti y (PO 4 ) 3 , 0 [117] Hereinafter, examples and experimental examples will be described in more detail in order to specifically describe the present invention, but the present invention is not limited by these examples and experimental examples. The embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to completely explain the present invention to those of ordinary skill in the art. [118] [119] Boehmite (AlO(OH)) as inorganic particles, polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP, 5130) as a binder, and a compound of formula 4 as a crosslinking agent are mixed in a ratio of 78:20:2 A slurry was prepared so that the content of the solid content was 18% by weight based on the total weight of the slurry. [120] Specifically, after adding 28.08 g of boehmite (AlO(OH)), 7.2 g of PVdF-HFP, and 0.72 g of a compound of Formula 4 to 164 g of acetone, a slurry was prepared. The slurry was formed into a separator and dried at 150° C. for 30 minutes to prepare a separator. After the crosslinking reaction was completed, additional drying was performed at room temperature to complete the separation membrane. [121] [122] A separator was prepared in the same manner as in Example 1, except that 0.0072 g of 2,2'-azobis (isobutyronitrile) as an initiator was added to the slurry of Example 1. [123] [124] A separator was prepared in the same manner as in Example 1, except that the slurry of Example 1 was changed to the compound of Formula 5 instead of the compound of Formula 4. [125] [126] A separator was prepared in the same manner as in Example 2, except that the slurry of Example 2 was changed to the compound of Formula 5 instead of the compound of Formula 4. [127] [128] In order not to contain the compounds of Formula 4 and Formula 5, which are crosslinking agents, boehmite (AlO(OH)) and polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP, 5130) were mixed in a ratio of 78:22. A separator was prepared in the same manner as in Example 1 except for use. [129] [130] The volume insulation resistance, electrical resistance, tensile strength, dimensional change rate, swelling, air permeability, thickness, and the like were measured for the separators of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1. [131] [Table 1] Industrial availability [132] As described above, the porous separator for an electrochemical device according to the present invention does not include a polyolefin substrate used as a separator substrate, unlike a conventional separator, and is made of a material containing inorganic particles, a binder, and a crosslinking agent. It is possible to overcome the problem of low thermal stability, and as the crosslinking agent compound forms a three-dimensional network structure, the insulating property of the separator may be remarkably improved. [133] In addition, as the crosslinking agent is transformed from a linear structure to a three-dimensional network structure, the tensile strength and elongation of the separator itself are improved, reducing the possibility of damage to the separator, and as a result, it is possible to prevent the occurrence of a short circuit inside the battery. have. [134] In addition, there are advantages of high stability against high-temperature environments, excellent electrolyte impregnation properties, and high ion transfer. Claims [Claim 1] A porous separator for an electrochemical device for securing electrical insulation between an anode and a cathode, wherein the separator does not contain a polyolefin substrate, and comprises inorganic particles, a polymer binder for bonding between the inorganic particles, and a crosslinking agent. An electrochemical device prepared by mixing, coating, drying, and then crosslinking the crosslinking agent, and the content of the crosslinking agent in the separator composition is greater than 0% to 5% by weight based on the total weight of the solid content. For porous separator. [Claim 2] The method of claim 1, wherein the crosslinking agent is a porous separator for an electrochemical device represented by the following formula, Formula 1 Formula 2 Formula 3 In Formulas 1 to 3, m is an integer of 1 to 100, and n is an integer of 0 to 30 And o is an integer of 1 to 1,000. The weight average molecular weight of Formulas 1 to 3 is 1,000 to 100,000. Formula 4 In Formula 4, m4 is an integer of 1 to 100, n4 is an integer of 0 to 30, and o4 is an integer of 1 to 1,000. The weight average molecular weight of Formula 4 is 1,000 to 100,000, and the p value is a variable dependent thereon. Formula 5 In Formula 5, a and c are integers of 1 to 30, b is an integer of 1 to 1000, and a weight average molecular weight is 1,000 to 100,000. [Claim 3] The electrochemical device of claim 1, wherein the inorganic particles are high-k inorganic particles having a dielectric constant of 1 or more, inorganic particles having piezoelectricity, inorganic particles having lithium ion transfer ability, alumina hydrate, or a mixture of two or more thereof. For porous separator. [Claim 4] The porous separator for an electrochemical device according to claim 2, wherein the inorganic particles are at least one selected from the group consisting of Al 2 O 3 , AlOOH, SiO 2 , MgO, TiO 2 and BaTiO 2 . [Claim 5] The method of claim 1, wherein the polymeric binder is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, poly Methyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyano Noethylpolyvinyl alcohol, cyanoethylcellulose, cyanoethyl sucrose, pullulan, carboxymethylcellulose, acrylonitrile styrene butadiene copolymer, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butyrene rubber (SBR), TFE, fluorine rubber, and a porous separator for an electrochemical device of at least one selected from the group consisting of polyimide. [Claim 6] The porous separator for an electrochemical device according to claim 5, wherein the polymeric binder is at least one selected from the group consisting of PVdF, TFE, and polyimide. [Claim 7] The porous separator for an electrochemical device according to claim 1, wherein the separator further comprises an initiator and/or a reaction catalyst. [Claim 8] The porous separator for an electrochemical device according to claim 1, wherein the reaction temperature of the crosslinking agent is 120°C to 160°C. [Claim 9] The porous separator for an electrochemical device according to claim 7, wherein the initiator is an azo-based compound or a peroxide-based compound. [Claim 10] The method of claim 9, wherein the azo-based compound is 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2 ,4-dimethylvaleronitrile) and 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) at least one selected from the porous separator for an electrochemical device. [Claim 11] The method of claim 9, wherein the peroxide-based compound is tetramethylbutylperoxy neodecanoate, bis(4-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxycarbonate, butylperoxy neode Decanoate, dipropyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, diethoxyethyl peroxy dicarbonate, diethoxyhexylperoxy dicarbonate, hexyl peroxy dicarbonate, dimethoxybutyl peroxy dicarbonate, bis( 3-methoxy-3-methoxybutyl) peroxy dicarbonate, dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl peroxy dicarbonate, 1,1,3, 3-tetramethylbutyl peroxypivalate, hexyl peroxy pivalate, butyl peroxy pivalate, trimethyl hexanoyl peroxide, dimethyl hydroxy butyl peroxy neo decanoate, amyl peroxy neo decanoate, Atofina, butyl peroxy neodecanoate, t-butylperoxyneoheptanoate, amylperoxy pivalate, t-butylperoxy pivalate, t-amyl peroxy-2-ethylhexanoate, lauryl per Oxide, dilauroyl (dilauroyl) peroxide, didecanoyl peroxide, benzoyl peroxide, or a porous separator for an electrochemical device at least one selected from among dibenzoyl peroxide. [Claim 12] The porous separator for an electrochemical device according to claim 1, wherein the separator has a thickness of 5 μm to 30 μm. [Claim 13] The porous separator for an electrochemical device according to claim 1, wherein the content of the crosslinking agent in the separator is greater than 0% to 5% by weight based on the total weight of the solid content. [Claim 14] The porous separator for an electrochemical device according to claim 1, wherein the separator has an air permeability of 50sec/100cc to 4,000sec/100cc. [Claim 15] An electrochemical device comprising a porous separator for an electrochemical device according to any one of claims 1 to 14.