KR100890594B1 - Separator with high permeability for electrochemical device and manufacturing method of the same - Google Patents

Abstract

The present invention is a nanofiber web prepared by the electrospinning of the spinning liquid having an air permeability of 1 ~ 30 s / 100cc, heat-treated to 200 ~ 400 ℃ at a temperature rising rate of 1 ~ 5 ℃ per minute under air or inert gas The present invention relates to a separator for an electrochemical device and a method of manufacturing the same.

The present invention is excellent in preventing internal short circuits of electrochemical devices such as lithium batteries because of high heat resistance at high temperatures, in particular, shrinkage at high temperatures, and excellent charge and discharge efficiency and cycle characteristics due to uniform and high air permeability. This excellent separator for electrochemical devices is provided.

Membrane, Nanofiber Web, Air Permeability, Shrinkage

Description

Separator with high permeability for electrochemical device and manufacturing method of the same}

The present invention relates to a separator for an electrochemical device, such as a lithium battery, and more particularly, to a separator for an electrochemical device having excellent heat resistance and air permeability using a nanofiber web manufactured by electrospinning, and a method of manufacturing the same.

Recently, as the electronic equipment becomes smaller and lighter due to the development of advanced electronic devices, the use of portable electronic devices is gradually increasing. Therefore, the necessity of a battery having a high energy density and a long lifespan used as a power source for such electronic devices is increasing, and research on lithium batteries is being actively conducted.

A lithium battery is a battery manufactured using a cathode, an anode, a separator interposed therebetween, and an electrolyte or gel polymer which provides a migration path of lithium ions between the cathode and the anode, wherein lithium ions are inserted / inserted at the cathode and the anode. Electrical energy is generated by oxidation and reduction reactions when deinsertion.

However, if the battery is overcharged due to charger malfunction, etc., and the voltage rises rapidly, excess lithium is precipitated at the cathode and lithium is excessively inserted at the anode, so that the cathode of the cathode / anode is thermally It becomes unstable. In this case, since the organic solvent of the electrolyte is decomposed to cause a rapid exothermic reaction, a situation such as thermal runaway occurs suddenly, causing a serious damage to the safety of the battery. As such, a local internal short circuit may occur due to overcharging, and the temperature rises intensively in the area where the internal short circuit occurs. However, when a local short circuit occurs, the separator does not properly perform a shutdown function (a function of suppressing current flow by suppressing ion movement when the temperature rises). Therefore, local short-circuits due to dendrite formation and temperature rise due to the thermal decomposition of the cathode and anode lead to thermal runaway, which eventually causes the battery to ignite and rupture.

Therefore, the separator of the lithium battery should have excellent heat resistance at high temperature in order to prevent internal short-circuit, and in particular, shrinkage at high temperature should be minimized. In addition, in order to minimize the miniaturization and electrical resistance of the battery pack with such characteristics, a thin film must be formed, and uniform and high porosity is required to improve charge and discharge efficiency and cycle characteristics.

The separator generally used in the prior art is composed of single layered or multi-layered thin films made of polyolefin. However, such a separator has a disadvantage in that heat resistance at high temperatures, in particular, shrinkage at high temperatures is not sufficient to stably prevent internal short circuits, and it is difficult to expect uniform and high porosity due to limitations in the manufacturing method.

In order to prevent the internal short circuit of the lithium battery, heat resistance at high temperature, in particular, shrinkage at high temperature is minimized, and uniform and high porosity is associated with charge and discharge efficiency and cycle characteristics. It is an object of the present invention to provide a separator for an electrochemical device, which can be absorbed quickly and is used as a separator for a lithium battery, which can greatly improve battery performance.

The present invention is a nanofiber web prepared by the electrospinning of the spinning liquid having an air permeability of 1 ~ 30 s / 100cc, heat-treated to 200 ~ 400 ℃ at a temperature rising rate of 1 ~ 5 ℃ per minute under air or inert gas Provided is a separator for an electrochemical device.

The separator for an electrochemical device is characterized by having an area shrinkage of 1 to 6.5% after maintaining for 30 minutes at 100 ℃ or less.

The separator for an electrochemical device is characterized by having an area shrinkage of 1 to 8% after maintaining for 30 minutes at 150 ℃ or less.

The separator for an electrochemical device is characterized by having an area shrinkage of 1 to 10% after maintaining for 30 minutes at 200 ° C or less.

The separator for an electrochemical device is characterized in that the separator is melted or greatly contracted at a temperature of 240 ° C. or lower so that an electrical short does not occur.

The separator for an electrochemical device preferably has a thickness of 1 to 50 μm.

The diameter of the nanofibers constituting the separator for the electrochemical device is preferably 10 ~ 700nm.

The spinning solution used to prepare the separator for the electrochemical device is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoro propylene copolymer, polyacrylonitrile, polyvinylidene chloride-acrylonitrile copolymer, polyethylene Oxide, polyurethane, polymethylacrylate, polymethylmethacrylate, polyacrylamide, polyvinylchloride, polyvinylacetate, polyvinylpyrrolidone, polytetraethylene glycol diacrylate, polyethyleneglycol dimethacrylate, cellulose It is preferable to include 5 to 99% by weight of at least one resin component selected from the group consisting of cellulose acetate on a solids basis.

The spinning solution also includes silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), BaTiO ₃ , LiO ₂ , LiF, LiOH, LiN, BaO, Na ₂ O, MgO, Li Precursor for ₂ CO ₃ , LiAlO ₃ , PTFE or the like or a mixture thereof may be further included in 1 to 20 parts with respect to 100 parts by weight of the solid resin.

The present invention also provides a separator for an electrochemical device, characterized in that the separator for the electrochemical device and the membrane having a shutdown function are alternately stacked in two or three layers regardless of the order.

In addition, between the separation membrane for the electrochemical device and the membrane having the shutdown function, or one or both surfaces of the outer surface of the laminate may be further laminated strength support film.

In addition, a porous inorganic (ceramic) nonelectroconductive membrane may be disposed between the separator for the electrochemical device and the membrane having the shutdown function or on one or both surfaces of the outer surface of the laminate, or a porous inorganic (ceramic) nonelectroconductive surface and inside. Porous carriers with a coating layer can be further laminated.

      The bonding method of heterogeneous membranes classified in the lamination methods is a direct coating method by electrospinning, an indirect coating between heterogeneous films, pressing while pressing by heating, and a laminating method between heterogeneous films. In addition, it is possible to include an ultrasonic fusion method and the like.

The present invention also,

(a) applying a high voltage to the spinning solution and electrospinning to prepare a nanofiber web;

(b) calendering the prepared nanofiber web to produce a predetermined thickness; And

(C) the method of producing a separator for an electrochemical device comprising the step of heat-treating the calendared nanofiber web in the air or inert gas at a temperature increase rate of 1 ~ 5 ℃ per minute to 200 ~ 400 ℃ to provide.

The spinning solution of step (a) may be prepared by melting the spinning material or dissolving in a solvent.

The present invention is excellent in the prevention of internal short circuit of electrochemical devices such as lithium batteries, because the heat resistance at high temperatures, in particular, the shrinkage at high temperatures is minimized, has a uniform and high porosity as well as existing products It has a high rate of air permeability that could not be exhibited in the US. Therefore, the separator for an electrochemical device having excellent instantaneous charge and discharge efficiency and cycle characteristics, which provides characteristics such as instantaneous discharge of high current required by an automotive battery, is required. to provide. In addition, the separator for the electrochemical device can absorb the electrolyte uniformly, and when used as a separator such as a lithium battery, greatly improves the performance of the battery, and is laminated with various membranes having different functions to be prepared as various types of separators. Can be.

The present invention is a nanofiber web prepared by the electrospinning of the spinning liquid having an air permeability of 1 ~ 30 s / 100cc, heat-treated to 200 ~ 400 ℃ at a temperature rising rate of 1 ~ 5 ℃ per minute under air or inert gas Provided is a separator for an electrochemical device.

The separator for an electrochemical device has an area shrinkage of 1 to 6.5% after maintaining for 30 minutes at 100 ° C. or less, an area shrinkage of 1 to 8% after maintaining for 30 minutes at 150 ° C. or less, and an area shrinkage after maintaining for 30 minutes at 200 ° C. or less. It is characterized by being 1 to 10%.

The separator for an electrochemical device is characterized in that the separator is melted or greatly contracted at a temperature of 240 ° C. or lower so that an electrical short does not occur.

In addition, the longitudinal size of the pores is 0.05-3 μm, and the porosity is 45-70%. In particular, the pores obtained by the method of the present invention has an elliptical shape in which the pores of the separator obtained by the existing stretching method are elongated in the longitudinal direction, whereas the pores obtained by the present invention are uniform in both the longitudinal direction and the transverse direction. It is characterized by having pores.

The separator for an electrochemical device preferably has a thickness of 1 to 50 μm, and the diameter of the nanofibers constituting the separator is preferably 10 to 700 nm.

Since the separator for an electrochemical device of the present invention is in the form of a nanofiber web, air permeability is much higher than that of the conventional separator, and thus, when used in an electrochemical device such as a lithium battery, the charge and discharge efficiency and cycle characteristics are excellent. . In addition, since the heat treatment process is performed at a temperature rising rate of 1-5 ° C. per minute under an air or inert gas to 200-400 ° C., the area shrinkage ratio is minimized at a high temperature, and used in an electrochemical device such as a lithium battery. Even in high temperature environments, the possibility of short circuit between electrodes can be minimized.

The spinning solution used to prepare the separator for an electrochemical device of the present invention may be prepared by melting the spinning material or dissolving it in a solvent. The spinning solution is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyvinylidene chloride-acrylonitrile copolymer, polyethylene oxide, polyurethane, poly Consisting of methyl acrylate, polymethyl methacrylate, polyacrylamide, polyvinylchloride, polyvinylacetate, polyvinylpyrrolidone, polytetraethylene glycol diacrylate, polyethylene glycol dimethacrylate, cellulose, cellulose acetate It is preferable to include 5 to 99% by weight of at least one resin component selected from the group based on solid content.

The spinning solution is also considering the mechanical strength of the separator for an electrochemical device, silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), BaTiO ₃ , LiO ₂ , LiF, LiOH, LiN, BaO, Na ₂ O, MgO, Li ₂ CO ₃ , LiAlO ₃ , PTFE, or a mixture thereof may further include 1 to 20 parts based on 100 parts by weight of the resin solids.

The separator for an electrochemical device of the present invention may be prepared by stacking a variety of membranes having different functions. For example, the separator for the electrochemical device and the membrane having a shutdown function may be manufactured in a form of two or three layers alternately regardless of the order. In addition, a strength support membrane may be further stacked between the separator for the electrochemical device and the membrane having the shutdown function, or on one or both surfaces of the outer surface of the laminate.

Shut down function (shut down) in the above means an operation stop function that allows the pores to be closed at a specific temperature, the strength support membrane means a membrane having a function to support the membrane to maintain a constant strength.

Specifically, the shutdown function is a means for controlling thermal runaway that may occur due to battery physical damage, internal defects or short circuits due to overcharging, and most of the pores are closed at a specific temperature (90 to 120 ° C), thereby blocking ion or current flow. Speak the function. The membrane having such a shutdown function may be laminated on the separator for an electrochemical device of the present invention in a state where it is combined with the strength support membrane.

As the film forming material capable of performing the function of shutdown and / or strength support, a polyolefin-based polymer is suitable. For example, in the case of PP / PE / PP membranes, the PE layer is melted at a certain temperature and the pores are closed, thereby providing a shutdown function. As the polyolefin-based polymer used in the composite membrane of the present invention, a polyethylene-based polymer or a polypropylene-based polymer is suitable. For example, a uniaxial or biaxially stretched PE single film, a PP single film, a PE / PP two-layer structure film, A polyolefin-based porous membrane or nonwoven fabric having a PP / PE / PP three-layer structure membrane or a composite multilayer structure composed of PE and PP; Composite constructions in which non-woven fabrics of the same kind of PE or PP are laminated; Polyamide-based porous membranes or nonwovens; Or a polyester-based porous membrane film or nonwoven fabric may be used. Preferably, a porous polyolefin-based membrane film of a PE single membrane, a PE / PP two-layer structure film, and a PP / PE / PP three-layer structure film having a shutdown function and / or a supporting function of a separator is used to prevent a short circuit between the two electrodes. . The polyolefin-based microporous membrane is one of the conventional methods disclosed in European Patent Nos. 1,146,577, US Patent 6,368,742, US Patent 5,691,077, US Patent 6,180,280, US Patent 5,667,911, US Patent 6,080,507, and the like. The membrane produced can be provided.

As the polyolefin microporous membrane, a commercially available polyolefin microporous film can be used. For example, Celgard's Celgard film (PE film, PP film, PP / PE / PP triple layer film) or Asahi Kasaei's Hipore film (PE), Tonen / ExxonMobil's Setela film (PE), Entek International Teklon film (PE) or the like can be used.

As the membrane which can be used for imparting a shutdown function in the separator for an electrochemical device of the present invention, the thickness of the polyolefin-based microporous membrane is 5 to 50 μm, porosity (porosity) [porosity (%)) = 1- ( Apparent density / resin density) × 100 of the film is preferably 30 to 80%. In addition, the tensile strength is 700 kg / cm 2 or more in the mechanical direction (MD), 150 kg / cm 2 or more in the transverse direction (CD), the punching strength is 200 g or more per mil (mil, 1 mil = 25.4 μm), and the shrinkage ratio is 100 ° C. Less than 10% for 1 hour, the average pore size is 0.005 ~ 3㎛ physical properties and electrical resistance of 130Ω ~ Ω at 10,000 ~ -cm ² It is preferable to use for the electrochemical device.

The present invention also,

(a) applying a high voltage to the spinning solution and electrospinning to prepare a nanofiber web;

(b) calendering the prepared nanofiber web to produce a predetermined thickness; And

(C) the method of producing a separator for an electrochemical device comprising the step of heat-treating the calendared nanofiber web in the air or inert gas at a temperature increase rate of 1 ~ 5 ℃ per minute to 200 ~ 400 ℃ to provide.

The spinning solution of step (a) may be prepared by melting the spinning material or dissolving in a solvent.

Among the methods for preparing the spinning solution in step (a), solvents used in the preparation of the spinning solution are DMA (dimethyl acetamide), DMF (N, N-dimethylformamide), NMP (N-methyl-2-pyrrolidinone), and DMSO ( dimethyl sulfoxide), tetra-hydrofuran (THF), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), propylene carbonate (PC), acetone, and the like. One or two or more selected species may be used.

 The electrospinning method of step (a) may employ a method known in the art without particular limitation. For example, as follows.

Electrospinning

A spinning solution prepared by dissolving a resin or the like, which is a raw material of the separator for an electrochemical device of the present invention, in a suitable solvent or melting at a high temperature is connected to an electrospinning nozzle using a supply device, and a high voltage generator is provided between the nozzle and the current collector. Electrospinning is carried out by forming a high electric field (~ 100kV) using. The magnitude of the electric field is related to the distance between the nozzle and the current collector, and in order to facilitate the electrospinning, the relationship between them is used in combination. In this case, as the electrospinning apparatus to be used, generally used ones may be used, and an electro-blowing method or a centrifugal electrospinning method may be used. Nanofiber web prepared by the above method is in the form of a nonwoven fabric composed mostly of less than 1㎛ diameter.

The heat treatment step of step (b) is a process of impregnating (stabilizing) the electrospun nanofiber web. Specifically, it is as follows.

Incompatibility (stabilization) treatment

The electrospun nanofiber web is moved to a hot air circulation path using a conveyer belt, and heat-treated to 200-400 ° C. at an elevated temperature rate of 1-5 ° C. per minute in an air or inert gas atmosphere to stabilize the fibers. To prepare. The insoluble fiber thus prepared is completely removed from the residual solvent present during the electrospinning, and the thermoplastic polymer structure is changed to a thermosetting polymer structure to improve heat resistance and handleability. The heat treatment temperature is appropriately selected from this point of view, and is generally set in the range of 200 to 400 ° C, preferably 230 to 350 ° C, more preferably about 250 to 350 ° C.

The separator for an electrochemical device of the present invention may be usefully used in lithium secondary batteries and the like. Specifically, the separator for an electrochemical device of the present invention is used in an electrochemical device such as a lithium secondary battery containing a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an organic electrolyte or gel polymer in a case. Therefore, it can be usefully used as a separator.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Example  1: Preparation of separator for electrochemical device

Polyacrylonitrile (PAN) was used to prepare a spinning solution having a concentration of 10% using DMF (dimethylformamide). At this time, the polyacrylonitrile solids were dissolved in DMF, the solvent, and then stirred at room temperature for 8 hours using a stirrer with a propeller so that the solids were evenly dispersed in the solvent. The stirred solution was stirred so as to be suitable for spinning so that the viscosity was too high to make spinning impossible or the viscosity was too low so that the spinning solution did not flow down. The spinning solution prepared in this way was connected to the spinneret, a voltage of 60 kV was applied to the nozzle, and the discharge was carried out at 0.05 to 1 cc / g per hole while maintaining the distance between the spinneret and the current collector at 60 cm. PAN nanofiber webs were prepared at a belt speed of 10 Hz.

The nanofiber web prepared above was put between two rolls heated at 120 ° C. to roll calendering to a thickness of 20 μm.

The roll calendered nanofiber web was heat-treated at 250 ° C. for 30 minutes at each temperature at an elevated rate of 3 ° C. per minute in the air to be infusible (stabilized) to prepare a separator for an electrochemical device .

Example  2: Preparation of separator for electrochemical device

Separation membrane for an electrochemical device was manufactured in the same manner as in Example 1 except that polyacrylonitrile (PAN) was used to prepare a spinning solution having a concentration of 17% using DMF (dimethylformamide) .

Example  3: Preparation of separator for electrochemical device

A separator for an electrochemical device was prepared in the same manner as in Example 1 except that polyvinylidene fluoride (PVdF) was used to prepare a spinning solution having a concentration of 10% using DMF (dimethylformamide) .

Example  4 ~ 6: Preparation of separator for electrochemical device

PAN and PVdF were mixed at a weight ratio of 70:30 (Example 4), 50:50 (Example 5) and 30:70 (Example 6), respectively, and the concentration was 10% using co-solvent DMF (dimethylformamide). Except that the room solution was prepared in the same manner as in Example 1 to prepare an electrochemical separator .

Test Example : Measurement of characteristics of membrane for electrochemical device

1.Measurement method

(1) pore size

Mean pore size (MFPS) and maximum pore size were measured using an automated capillary flow porometer (PMI (Porous Materials Inc.), Model CFP-1200AEL (CFP-34RTF8A-X-6-L4)] It was. The wetting fluid used for the measurement was galwick acid (surface tension 15.9 dynes / cm). The diameter of the adapter plate was 21 mm, measured by wet-up / dry-up method.

(2) Porosity measurement

The method of measuring porosity measured the diameter of pores filled by mercury at a certain pressure in accordance with ASTM D 4284-92. The applied pressure ranges from 0.5 to 60,000 psi continuously while applying a constant pressure. The porosity was measured and porosity was measured by measuring the volume of mercury filled in the separator. The measurement is automatically measured and the calculated value is output. The instrument used was the Autopore IV 9500 from Micrometrics, and the measurable pore size ranged from 0.003 µm to 360 µm.

(3) Air permeability measurement

The air permeability of the separator for an electrochemical device of the present invention was measured according to JIS P8117. As a measuring apparatus, B type Gurley densometer (manufactured by Toyo Seiki Co., Ltd.) was used. The separator for electrochemical elements was fixed firmly in a circular hole having a diameter of 28.6 mm and an area of 645 mm ² , and air in the cylinder was passed out of the cylinder from the test circular hole by a mass of 567 g of the inner cylinder. The time to pass through 100 cc of air was measured and referred to as air permeability.

(4) Heat shrinkage measurement of separator for electrochemical device

Insert the separator for electrochemical device (5 cm × 2 cm) between the slide glass, clip both ends into the oven to maintain the set temperature, hold for 30 minutes, remove the membrane from the oven and cool it at room temperature. The area shrinkage was then measured.

2. Example  Characteristics of Separators for Electrochemical Devices 1 to 6

(1) thickness and compressibility of separators for electrochemical devices

(2) pore size and porosity of membrane for electrochemical device

1) Comparative Example 1: PE separator with a thickness of 20㎛ manufactured by stretching by wet method (product of Celgard)

2) Comparative Example 2: PE membrane of 20㎛ manufactured by blowing agent by dry method (product of Asahi Kasahi)

(3) Air permeability of separator for electrochemical device

1) Comparative Example 1: PE separator with a thickness of 20㎛ manufactured by stretching by wet method (product of Celgard)

2) Comparative Example 2: PE membrane of 20㎛ manufactured by blowing agent by dry method (manufactured by Asahi Kasahi)

(4) area shrinkage of separators for electrochemical devices

NOTE 200 of the separator of Example 1 Shrinkage at ℃ was 8%

Note 1) The separator of Example 1 is the shrinkage rate when the belt speed is 10 Hz during electrospinning.

(5) Weight analysis according to temperature of separator for electrochemical device

The thermal weight change was measured using a thermo-gravimetric analyzer (TGA) while raising the temperature from room temperature to 250 ° C. during heat treatment of the nanofiber web prepared in Example 1 (thickness 20 μm after calendering). . In the case of the separator for an electrochemical device from which the solvent remaining on the membrane was removed, almost no change in weight occurred (see FIG. 1).

1 is a planar photograph of a separator for an electrochemical device manufactured in Example 1 of the present invention.

Figure 2 is a cross-sectional photograph of a separator for an electrochemical device prepared in Example 1 of the present invention.

3 is a graph showing the thermogravimetric change of the separator for an electrochemical device manufactured in Example 1 of the present invention.

4 is a schematic diagram of an apparatus for manufacturing a separator for an electrochemical device of the present invention.

Figure 5 is a graph showing the shrinkage ratio of the temperature of the separator for an electrochemical device prepared in Example 1 of the present invention.

Claims (16)

A nanofiber web prepared by electrospinning of spinning solution, having an air permeability of 1 to 30 s / 100cc, the diameter of the nanofibers constituting the nanofiber web is 10 to 700 nm, and 1 to 1 minute per minute under air or an inert gas. Separation membrane for an electrochemical device, characterized in that the heat treatment to 200 ~ 400 ℃ at a temperature increase rate of 5 ℃. The separator for an electrochemical device according to claim 1, wherein the area shrinkage ratio is 1 to 6.5% after maintaining for 30 minutes at 100 ° C or less. The separator for an electrochemical device according to claim 1, wherein the area shrinkage ratio is 1 to 8% after maintaining for 30 minutes at 150 ° C or less. The separator for an electrochemical device according to claim 1, wherein the area shrinkage ratio is 1 to 10% after 30 minutes of holding at 200 ° C or less. The separator for an electrochemical device according to claim 1, wherein the separator for the electrochemical device does not melt at 240 ° C. or less. The separator for an electrochemical device according to claim 1, wherein the separator has a thickness of 1 to 50 µm. delete The method of claim 1, wherein the spinning solution is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoro propylene copolymer, polyacrylonitrile, polyvinylidene chloride-acrylonitrile copolymer, polyethylene oxide, polyurethane, poly Methyl acrylate, polymethyl methacrylate, polyacrylamide, polyvinylchloride, polyvinylacetate, polyvinylpyrrolidone, polytetraethylene glycol diacrylate, polyethylene glycol dimethacrylate, cellulose, cellulose acetate Separation membrane for an electrochemical device comprising at least one resin component selected from 5 to 99% by weight based on solids. The method of claim 8, wherein the spinning solution is silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), BaTiO ₃ , LiO ₂ , LiF, LiOH, LiN, BaO, Na ₂ O, MgO, Li ₂ CO ₃ , LiAlO ₃ , PTFE, or an electrochemical device separator, characterized in that it further comprises 1 to 20 parts with respect to 100 parts by weight of the resin solids. A separator for an electrochemical device according to any one of claims 1 to 6, 8 or 9 and a membrane having a shutdown function are alternately stacked in two or three layers irrespective of the order. The separator for an electrochemical device according to claim 10, wherein a strength support membrane is further laminated between the separator for the electrochemical device and the membrane having the shutdown function or on one or both surfaces of the outer surface of the laminate. The porous inorganic (ceramic) non-electroconductive membrane between the separator for an electrochemical device and the membrane having the shutdown function or on one or both surfaces of the laminate, or a porous inorganic (ceramic) on the surface and inside. Separation membrane for an electrochemical device, characterized in that the porous carrier having a non-conductive conductive layer is further laminated. (a) applying a high voltage to the spinning solution and electrospinning to prepare a nanofiber web; (b) calendering the nanofiber web prepared in step (a) to produce a constant thickness; And (C) the membrane for electrochemical device comprising the step of heat-treating the calendered nanofiber web in step (b) to 200 ~ 400 ℃ at a temperature increase rate of 1 ~ 5 ℃ per minute under air or inert gas Manufacturing method. The method of manufacturing a separator for an electrochemical device according to claim 13, wherein the spinning solution of step (a) is prepared by melting the spinning material or dissolving it in a solvent. In the electrochemical device containing a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode and an organic electrolyte or gel polymer in the case, The separator is an electrochemical device, characterized in that the separator for an electrochemical device according to any one of claims 1 to 6, 8 or 9. In the electrochemical device containing a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode and an organic electrolyte or gel polymer in the case, The separator is an electrochemical device, characterized in that the separator for an electrochemical device of claim 10.

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