KR20160057345A - Method for manufacturing separator for secondary cell, separator for secondary cell and method for manufacturing secondary cell - Google Patents

Abstract

The present invention relates to a method for manufacturing a separator for a secondary battery, which can optimally apply an electrode adhesion layer material to both surfaces of a separator for a secondary battery having one surface or both surfaces of a porous separator substrate coated with an inorganic material; to a separator for a secondary battery manufactured thereby; and to a method for manufacturing a secondary battery including the same. The method for manufacturing a separator for a secondary battery comprises the steps of: (a) manufacturing a porous substrate having an inorganic layer formed thereon by coating one surface of the porous substrate with an aqueous inorganic dispersion; and (b) forming an electrode adhesion layer, which is composed of an aqueous binder composition, on both surfaces of the porous substrate by individually or simultaneously applying the aqueous binder composition to the surface of the inorganic layer of the porous substrate, and a surface where an inorganic surface has not been formed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a secondary battery separator, a secondary battery separator manufactured by the method, and a manufacturing method of a secondary battery including the secondary battery separator,

The present invention relates to a method of manufacturing a separator of an electrochemical device such as a lithium secondary battery, a secondary battery separator manufactured thereby, and a method of manufacturing a secondary battery including the same.

The separator (separator) is provided between the positive electrode and the negative electrode of the secondary battery for securing electrochemical stability. Particularly, adhesion layer is applied for adhesion between inorganic reinforced fine particle coated SRS and electrodes. Conventionally, inorganic fine particles and binder are mixed and coated on organic solvent, and then, In order to reduce the cost, a method of applying a dispersion of an inorganic material using water as a solvent to a separation membrane without using an organic solvent has been changed to a process of separating the phase separation It became difficult to apply the method.

It is further preferable to use a water-soluble material for the adhesive layer in order to reduce the process cost. When an adhesive layer is applied to a separation membrane coated with an inorganic material, a contact layer coating method such as a comma coating and a bar coating may damage the coated inorganic layer because an inorganic layer is coated on the raw material It is not preferable. Therefore, it is very advantageous to apply non-contact type coating, which can be realized by dip coating, spray coating or ink jet coating.

Dip coating and spray coating have the disadvantage that it is difficult to apply the binder uniformly in a desired pattern. Also, in the case of dip coating, since the lower inorganic particle coating layer is to be dried so as not to be damaged when it is immersed in the upper binder coating layer solution, it is necessary to coat and dry the inorganic layer (first step), binder application and drying The process must be constituted in two steps of the process (step).

In addition, when the inorganic material dispersed in water is coated on the separating membrane fabric, the surface characteristics of the both surfaces are different due to the surface energy difference between the inorganic layer and the separating membrane fabric. Thus, for example, it is not easy to apply a single binder solution to a dip coating to make a desired pattern on a separator, or to optimally adjust the electrode adhesive layer materials on both sides in one process.

KR 10-2012-0150587 A

In order to solve the problems of the prior art, the present invention provides a method for manufacturing a secondary battery separator capable of optimally applying an electrode adhesive layer material to both surfaces of a secondary battery separation membrane coated with an inorganic material on one or both surfaces of a porous separation membrane substrate, And a method for manufacturing a secondary battery including the separator.

In order to solve the above problems, the present invention provides a method for manufacturing a porous substrate, comprising the steps of: (a) preparing a porous substrate on which an inorganic layer is formed by coating an aqueous inorganic dispersion on an end surface of the porous substrate; And (b) a step of applying an aqueous binder composition to the surface of the inorganic material layer of the porous substrate and the surface of the porous substrate on which the inorganic material layer is not formed, respectively, to form an electrode adhesive layer comprising an aqueous binder composition on both surfaces of the porous substrate A method of manufacturing a battery separator is provided.

In addition, the present invention provides a secondary battery separator manufactured by the above production method.

The present invention also provides a method of manufacturing a porous substrate, comprising the steps of: (a) preparing a porous substrate on which an inorganic layer is formed by coating an aqueous inorganic dispersion on an end face of the porous substrate by an aqueous system; (b) forming an electrode adhesive layer composed of an aqueous binder composition on both sides of the porous substrate by applying an aqueous binder composition to both the inorganic layer side of the porous substrate and the inorganic layer side, And adhering and laminating the electrode layers to both surfaces of the porous substrate on which the electrode adhesive layer is formed, respectively.

According to the present invention, by applying an electrode adhesive layer to a separator coated with an inorganic material using an inkjet process, it is possible to manufacture a secondary battery separator by implementing a desired pattern and an application amount of the electrode adhesive layer on both sides of the separator, have.

1 is a schematic view of a secondary battery separator manufactured according to the present invention.

Hereinafter, the present invention will be described in more detail.

(A) preparing a porous substrate having an inorganic layer formed by coating an aqueous inorganic dispersion on an end face of the porous substrate by an aqueous system; And (b) a step of applying an aqueous binder composition to the surface of the inorganic material layer of the porous substrate and the surface of the porous substrate on which the inorganic material layer is not formed, respectively, to form an electrode adhesive layer comprising an aqueous binder composition on both surfaces of the porous substrate A method of manufacturing a battery separator is provided.

The method of coating an aqueous inorganic dispersion with an aqueous solution on the cross-section of the porous substrate may be dip coating, spraying, ink jet, laser printing, screen printing, or dispensing.

In the present invention, the term " aqueous inorganic dispersion liquid " means a dispersion liquid in which solid components such as binder polymer and / or inorganic particles are dispersed in an aqueous medium such as water. Further, the term 'aqueous system' means a process system using a dispersion in which an aqueous solvent such as water is used as a medium.

As the porous substrate, any conventional porous substrate used in a separator of an electrochemical device can be used. For example, polyolefin-based compounds such as polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate , Polyimide, polyether ether ketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene etthalene, polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, hexa Fluoroethylene copolymer, fluoropropylene copolymer, polyethylene, polypropylene, etc., or a mixture of two or more of them, or a fibrous substrate.

The thickness of the porous substrate is not particularly limited, but is preferably 5 to 50 μm, and the pore size and porosity present in the porous substrate are also not particularly limited, but are preferably 0.001 to 50 μm and 10 to 99%, respectively.

In the separator manufacturing method of the present invention, the inorganic particles constituting the inorganic material layer formed on the cross section of the porous substrate may be used either individually or in combination with inorganic particles having a dielectric constant of 5 or more or lithium ion- .

In the separator according to the embodiment of the present invention, the inorganic particles used for forming the inorganic layer are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles usable in the present invention are not particularly limited as long as oxidation and / or reduction reaction does not occur in the operating voltage range of the applied electrochemical device (for example, 0 to 5 V based on Li / Li +). Particularly, when inorganic particles having ion transfer ability are used, the ion conductivity in the electrochemical device can be increased to improve the performance. When inorganic particles having a high dielectric constant are used as the inorganic particles, dissociation of an electrolyte salt, for example, a lithium salt, in the liquid electrolyte is also increased, and ion conductivity of the electrolyte can be improved. For the reasons described above, it is preferable to use high-permittivity inorganic particles having a dielectric constant of 5 or more, preferably 10 or more, inorganic particles having lithium ion-transporting ability, or a mixture thereof, as the inorganic particles. Non-limiting examples of the inorganic particles is less than a dielectric constant of 5 is BaTiO3, Pb (Zr, Ti) O 3 (PZT), Pb 1 - x La x Zr 1 -y Ti y O 3 (PLZT), PB (Mg 3 Nb _{2/3) O 3 -PbTiO 3 (PMN} -PT), hafnia _{(HfO 2), SrTiO 3,} SnO 2, CeO 2, MgO, NiO, CaO, ZnO, ZrO 2, Y 2 O 3, Al 2 O ₃ , boehmite (? -AlO (OH), TiO ₂ , SiC, or a mixture thereof).

In particular, the above-described BaTiO3, Pb (Zr, Ti) O 3 (PZT), Pb1-xLaxZr1-yTiyO3 (PLZT), Pb 1- xLa x Zr 1-y Ti y O 3 (PLZT), PB (Mg 3 Nb 2 _{/ 3} ) Inorganic particles such as O ₃ -PbTiO ₃ (PMN-PT) and hafnia (HfO ₂ ) exhibit a high dielectric constant of not less than 100 with a high permittivity constant. In addition, when a certain pressure is applied, By having a piezoelectricity in which a potential difference is generated between both surfaces, it is possible to prevent internal short-circuiting of both electrodes due to an external impact, thereby improving the safety of the electrochemical device. Further, when the above-mentioned high-permittivity inorganic particles and inorganic particles having lithium ion transferring ability are mixed, their synergistic effect can be doubled.

In the separator according to an embodiment of the present invention, the inorganic particle size of the inorganic layer is not limited. However, in order to form a coating layer having a uniform thickness and a proper porosity, the inorganic layer may have a particle size of 0.001 to 10 탆, 3 mu m.

The aqueous-based inorganic dispersion may include a first polymer binder. It said first polymeric binder is a polymer that can be used if the inorganic material layer is formed with inorganic particles can be all used, and preferably a solubility parameter of 15 to 45Mpa ^1/2 in the polymer is used. The binder polymer binds and stabilizes the inorganic particles. Non-limiting examples of such a binder polymer include polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichlorethylene, Polyolefins such as polymethylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, , Cyanoethylcellulose (cyanoethylcellulose) , Cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, styrene butadiene rubber (SBR). These may be used alone or in combination of two or more thereof.

The composition ratio of the inorganic particles of the inorganic layer and the first binder polymer in the separator according to an embodiment of the present invention is preferably in the range of 50:50 to 99: 1, more preferably 70:30 to 95: 5. When the content ratio of the inorganic particles to the first binder polymer is less than 50:50, the content of the polymer is increased and the improvement of the thermal stability of the separator may be deteriorated. In addition, the pore size and porosity due to the reduction of the void space formed between the inorganic particles may be reduced, resulting in deterioration of the final cell performance. If the content of the inorganic particles exceeds 99 parts by weight, the fillerability of the inorganic layer may be weakened because the content of the binder polymer is too small. The thickness of the inorganic layer composed of the inorganic particles and the binder polymer is not particularly limited, but is preferably in the range of 0.01 to 20 mu m. The pore size and porosity are also not particularly limited, but the pore size is preferably in the range of 0.001 to 10 mu m, and the porosity is preferably in the range of 10 to 99%. The pore size and porosity mainly depend on the size of the inorganic particles. For example, when inorganic particles having a particle size of 1 탆 or less are used, pores formed are also about 1 탆 or less. Such a pore structure is filled with an electrolyte solution to be injected at a later stage, and the filled electrolyte serves as an ion transfer function.

According to the step (a), the hydrophobic surface of the porous substrate itself and the hydrophilic surface due to the inorganic layer exist in the porous substrate, and both surfaces of the porous substrate have different surface energies.

In one embodiment of the present invention, a step of drying or semi-drying the liquid component of the inorganic dispersion liquid may be added after performing the step (a) and before the step (b).

In the step (b), the method of applying the aqueous binder composition to both surfaces of the porous substrate is preferably a non-contact method. Examples thereof include a spray, an inkjet printing method, a laser printing method, a screen printing method, a dispensing method, and the like, and their application methods may be appropriately selected according to the purpose of the present invention . In the present invention, the ink-jet printing method can be uniformly applied in a desired pattern. Therefore, the aqueous binder composition may be an inkjet ink composition for applying an electrode adhesive layer.

In the present invention, the aqueous binder composition is a polymer solution in which a second polymeric binder is dispersed in a solvent, and the solvent includes an aqueous solvent compatible with water such as water and / or ethanol. For the second polymeric binder, the contents of the first polymeric binder described above may be referred to.

According to a specific embodiment of the present invention, it is preferable that the aqueous binder composition contains the second binder polymer in an amount of 3 to 25% by weight based on 100% by weight of the aqueous binder composition. The content of the second polymeric binder is related to the thickness of the adhesive layer. If the thickness of the electrode adhesive layer is high, the thickness of the assembly may increase during stack-folding. If the thickness of the electrode adhesive layer is low, The separation between the separator and the electrode may occur, and an appropriate level of the thickness of the electrode adhesion layer is required.

In one embodiment of the present invention, the water-based binder composition is obtained by ink-forming an aqueous binder polymer and does not excessively penetrate the porous substrate during the process, Is present mainly on the necessary surface, and even when the same amount of binder is applied, the adhesive strength is superior to that of dip coating.

On the other hand, binder polymers dispersed only in water are not easy to apply inkjet process with high surface tension and low viscosity. The aqueous binder composition thus comprises a high boiling point solvent to ensure the ink jetting processability of the aqueous binder composition. In the present invention, the high boiling point solvent has a boiling point of 140 to 210 DEG C, and is highly compatible with water and does not lower the dispersibility of the aqueous binder composition.

In one embodiment of the present invention, the high boiling solvent is selected from the group consisting of propylene glycol, butyl cellosolve, 1,2-hexanediol, butyl carbotal, 2 Pyrollidone. ≪ / RTI >

According to a specific embodiment of the present invention, the aqueous binder composition comprises 3 to 25% by weight of a second polymer binder; 45 to 60% by weight aqueous solvent; 21 to 50% by weight of a high-boiling solvent; Based ink composition.

According to a preferred embodiment of the present invention, butyl cellosolve can be used as the high-boiling solvent. Further, in order to ensure the jetting processability of the ink-jet ink having a low viscosity, 1,2-hexanediol having a boiling point and viscosity higher than that of butyl cellosolve in a compatible solvent can be used.

Accordingly, according to a specific embodiment of the present invention, the aqueous binder composition contains 3 to 25% by weight; 45 to 60% by weight of water; 21 to 40% by weight of butyl cellosolve; 0.1 to 10% by weight of 1,2-hexanediol.

In one specific embodiment of the present invention, the aqueous binder composition may further comprise a surfactant. The addition of the surfactant decreases the surface tension of the ink to improve the ink jetting property and the sustainability. In one specific embodiment of the present invention, the content of the surfactant may be in the range of 0.01 to 2 parts by weight based on 100 parts by weight of the aqueous binder composition.

In one specific embodiment of the present invention, the surfactant may include non-ionic, cationic and silicone surfactants conventionally used in aqueous slurries, specifically Dynol 360, 604, 607, 800, 810, 960, 980, Surfynol 104, 420, 440, 465, 485, and the like, but the present invention is not limited thereto.

In one specific embodiment of the present invention, the aqueous binder composition has a viscosity of 6 to 18 cps.

In one embodiment of the present invention, the aqueous binder composition can be applied to the surface of the porous substrate with a loading amount (loading amount) ranging from 0.35 to 0.8 g / m ² . Further, in one specific embodiment of the present invention, the aqueous binder composition may be applied in an appropriate pattern such as dot, sprite, or the like.

According to a specific embodiment of the present invention, the aqueous binder composition may be applied in a dot pattern. In this case, the size of the dot may be 100 to 150 탆 within the range of the loading amount described above, The interval can be controlled to 100 to 150 mu m.

Aqueous inks containing polymeric binders such as latex are widely used as printing inkjet inks and are used to improve adhesion and print quality between substrate and ink through physicochemical bonding with special surface treated media There is a purpose. Therefore, the purpose of the present invention is different from that of the water-based polymeric binder of the present invention and the aqueous binder composition containing the two, which serve to bond two different kinds of base materials.

In one embodiment of the present invention, in step (b), the aqueous binder composition may be applied to the both sides of the porous substrate in different amounts per unit area. It is also possible to form a desired pattern upon application. Software may be used for this purpose.

(Amount of loading) of the aqueous binder composition applied to the surface of the inorganic material layer of the porous substrate is 0.3 to 0.9 g / m < ² > to ensure adhesion between the hydrophilic inorganic material layer of the porous substrate and the electrode.

The amount of the aqueous binder composition to be applied to the surface of the porous substrate on which the inorganic layer is not formed is 0.3 to 0.9 g / m ² in order to secure the adhesion between the hydrophobic surface of the porous substrate and the electrode on which the inorganic layer is not formed .

According to an embodiment of the present invention, when an aqueous binder composition is introduced by an ink-jet method, it is possible to effectively realize discrete dots of 100 to 150 μm at a high speed (40 m / min or more) , And the viscosity of the binder solution may have a wide range.

The present invention provides a secondary battery separator manufactured by the above manufacturing method.

The thus-fabricated separator according to an embodiment of the present invention is used in an electrochemical device interposed between a cathode and an anode. The electrochemical device includes all devices that perform an electrochemical reaction, and specific examples include capacitors such as all kinds of primary, secondary cells, fuel cells, solar cells, or super capacitor devices. Particularly, a lithium secondary battery including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery is preferable.

The present invention also provides a method of manufacturing a porous substrate, comprising the steps of: (a) preparing a porous substrate on which an inorganic layer is formed by coating an aqueous inorganic dispersion on an end face of the porous substrate by an aqueous system; (b) forming an electrode adhesive layer composed of an aqueous binder composition on both sides of the porous substrate by applying an aqueous binder composition to both the inorganic layer side of the porous substrate and the inorganic layer side, And adhering and laminating the electrode layers to both surfaces of the porous substrate on which the electrode adhesive layer is formed, respectively.

In one embodiment of the present invention, in the step (a), the aqueous inorganic dispersion may be prepared by dispersing inorganic particles and a polymeric binder in an aqueous medium such as water. The inorganic particles and the polymeric binder refer to the above-mentioned contents for the aqueous inorganic dispersion. The aqueous inorganic dispersion may be prepared by dispersing inorganic particles in an emulsion solution of a binder polymer formed by emulsion polymerization.

In one embodiment of the present invention, a step of drying or semi-drying the liquid component of the inorganic dispersion before the step (b) may be added.

The electrode to be bonded to the electrode adhesive layer in the step (c) is not particularly limited, and the electrode active material may be bound to the electrode current collector according to a conventional method known in the art. Examples of the cathode active material include, but are not limited to, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a combination thereof It is preferable to use a lithium composite oxide. As a non-limiting example of the anode active material, a conventional anode active material that can be used for an anode of an electrochemical device can be used. In particular, lithium metal or a lithium alloy, carbon, petroleum coke, activated carbon, Lithium-adsorbing materials such as graphite or other carbon-based materials and the like are preferable. Non-limiting examples of the cathode current collector include aluminum, nickel, or a combination thereof, and examples of the anode current collector include copper, gold, nickel, or a copper alloy or a combination thereof Foil to be manufactured, and the like.

As a process of applying the separator according to an embodiment of the present invention to a battery, a lamination, stacking and folding process of a separator and an electrode can be performed in addition to a general winding process.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the above-described embodiments. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

≪ Example 1 >

(CMC) (trade name, manufactured by Nabaltec Co., Ltd., Apyral AOH60) and styrene butadiene rubber (SBR) (JSR Corporation, TRD102A) Daicel Chemical Industry, 1220) 90: 6: 4, dissolving in water at 50 DEG C for about 3 hours or more, and then pulverizing and dispersing the inorganic particles using a ball mill method for 12 hours or longer, 30% water-based inorganic dispersion was prepared.

The aqueous inorganic dispersion thus prepared was coated on a polyethylene porous substrate (porosity of 45%) having a thickness of 12 탆 by a dip coating method. At this time, the thickness of the coating layer was adjusted to about 20 탆.

Next, an aqueous binder composition was prepared by mixing 70% by weight of a water-dispersible acrylic polymer binder (Zeon, 30% solids), 25% by weight of butyl cellosolve and 5% by weight of 1,2-hexanediol. Further, 0.1 part by weight of Surfynol 104 was further added to 100 parts by weight of the binder composition. It was confirmed that the viscosity of the obtained aqueous binder composition was 3 to 6 cP and that all the nozzles could be jetted. The mixed solvent has a boiling point of 150 ° C or higher and is excellent in compatibility with water to enable inkjet jetting. Surfynol 104, which is a surfactant, lowers the surface tension of the ink so as to have stable jetting stability.

The inorganic coating layer of the polyethylene porous substrate was subjected to patterning with a dot spacing of 150 탆 by the ink jet process using the aqueous binder composition. The dot size was about 100 탆, and dot patterns were formed at equal intervals. Air (N ₂ ) gas was blown or passed through an oven to improve the drying speed of the aqueous binder after application of the binder.

After the base material coated with the aqueous binder and the Cu electrode were passed through a laminator at a high temperature (100 ° C) to form a laminate, the adhesive strength to the electrodes was tested.

≪ Example 2 >

dot interval of 125 [micro] m.

≪ Example 3 >

dot spacing of 100 占 퐉, and a pattern was formed in a planar shape.

<Example 4>

The procedure of Example 1 was repeated except that the polyethylene porous substrate was patterned at a dot spacing of 150 占 퐉 on the substrate.

&Lt; Example 5 >

The procedure of Example 1 was repeated except that the polyethylene porous substrate was patterned to have a dot spacing of 125 탆.

&Lt; Example 6 >

The procedure of Example 1 was repeated except that the polyethylene porous substrate was patterned at a dot interval of 100 占 퐉 to form a pattern in a planar shape.

&Lt; Comparative Example 1 &

The procedure of Example 1 was repeated except that Zeon aqueous binder (LP-PX11) was applied to the inorganic coating layer of a polyethylene porous substrate by a dip coating process, followed by dip coating followed by drying. After the dip coating, a sample coated with an aqueous binder on the inorganic coating layer of the polyethylene porous substrate was obtained through a drying process.

&Lt; Comparative Example 2 &

The procedure of Example 1 was repeated except that Zeon aqueous binder (LP-PX11) was applied to the inorganic coating layer of a polyethylene porous substrate by a dip coating process, followed by dip coating followed by drying. After the dip coating, a sample coated with an aqueous binder on the circular cross section of the polyethylene porous substrate was obtained through a drying process.

Test Example 1 : Adhesion measurement method

Each of the separators prepared in Examples 1 to 6 and Comparative Examples 1 and 2 was folded and laminated on polyethylene terephthalate (PET), and the separator was bonded at 100 ° C using a roll laminator. After the bonded separator was cut to a width of 25 mm and a length of 120 mm, the force (gf / 25 mm) necessary for desorbing the bonded separator was measured using a tensile strength measuring instrument. The measurement results are shown in Table 1 below.

Test Example 2 : Separator  Air permeability evaluation

The separators prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were cut into 50 mm × 50 mm to prepare samples. The time (in seconds) it takes for 100 ml of air to completely pass through the prepared samples is measured and shown in Table 1 below.

Inkjet application DIP coating materials SRS coating layer fabric SRS coating layer fabric division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Dot pitch
(탆) 150 125 100 150 125 100 Loading amount
(g / m ² ) 0.35 0.51 0.8 0.35 0.51 0.8 1.0 (based on double-coated) Adhesion
(gf / 25 mm) 6.5 to 7.5 10 to 10.5 17 ~ 17.2 35 ~ 39 39 to 43 52 to 60 12.5 to 17.7 6.3 to 7.4 Ventilation
(second) 173 260 375 165 176 390 346

As shown in Table 1, it was confirmed that Examples 1 to 3, in which a binder was applied to the inorganic coating layer of the substrate, had similar adhesive strength as compared with Comparative Example 1. In Examples 4 to 6 in which the binder was applied to the circular cross section of the substrate, higher adhesion was measured than in Comparative Example 2. In the case of Comparative Example 2, a 0.8 g / m &lt; ² &gt; binder was applied to the SRS coating layer and a 0.2 g / m &lt; ² &gt; As a result of comparing the loading amounts of Example 4 and Comparative Example 2, it can be confirmed that the present invention can have a high adhesive force even with a low loading amount.

Claims (15)

(a) preparing a porous substrate on which an inorganic layer is formed by coating an aqueous inorganic dispersion on an end face of the porous substrate with an aqueous system; And
(b) applying an aqueous binder composition to the surface of the inorganic material layer and the surface of the inorganic material layer of the porous substrate, respectively, or simultaneously to form an electrode adhesive layer comprising an aqueous binder composition on both surfaces of the porous substrate A method of manufacturing a separator. The method according to claim 1,
Wherein a method of coating an aqueous inorganic material dispersion on an end surface of the porous substrate by an aqueous system is dip coating, spraying, ink jet, laser printing, screen printing, or dispensing. The method according to claim 1,
Wherein the porous substrate comprises a polyolefin-based compound. The method according to claim 1,
Wherein the porous substrate has a thickness of 5 to 50 占 퐉. The method according to claim 1,
Wherein the average particle diameter of the inorganic material is 0.001 to 10 mu m. The method according to claim 1,
Wherein the method of applying the aqueous binder composition to the porous substrate in the step (b) is a non-contact type spray, ink jet, laser printing, screen printing, or dispensing method. The method according to claim 1,
Wherein the method of applying the aqueous binder composition to the porous substrate in the step (b) is an inkjet method. The method according to claim 1,
The aqueous binder composition is applied by inkjet printing at a loading of 0.35 to 0.8 g / m ^{2 under} the control of dot sizes of 100 to 150 탆 and dot spacing of 100 to 150 탆. (Method for manufacturing secondary battery separator). The method according to claim 1,
Wherein the aqueous binder composition comprises an aqueous latex binder. The method according to claim 1,
The aqueous binder composition comprises 3 to 25% by weight of a polymer binder; 45 to 60% by weight aqueous solvent; And 21 to 50% by weight of a high boiling point solvent. The method according to claim 1,
Wherein the coating amount of the aqueous binder composition applied to the surface of the inorganic material layer of the porous substrate is 0.3 to 0.9 g / m ² in order to secure the adhesion between the inorganic material layer and the electrode of the porous material. The method according to claim 1,
The amount of the aqueous binder composition to be applied to the surface of the porous substrate on which the inorganic layer is not formed is 0.3 to 0.9 g / m ² in order to ensure adhesion between the surface of the porous substrate on which the inorganic layer is not formed and the electrode Wherein the separator is made of a thermoplastic resin. The method according to claim 1,
Wherein a coating amount of the aqueous binder composition for securing an adhesion force between the porous substrate surface having hydrophobic properties and the electrode on which the inorganic layer is not formed is 0.3 to 0.9 g / m ² . A secondary battery separator produced by the manufacturing method of claim 1. (a) coating a cross-section of a porous substrate with an aqueous inorganic dispersion to prepare a porous substrate having an inorganic layer formed thereon;
(b) applying an aqueous binder composition to an inorganic layer surface of the porous substrate and a surface not having an inorganic layer simultaneously to form an electrode adhesive layer composed of an aqueous binder composition on both surfaces of the porous substrate; and
(c) bonding and laminating the electrode layers on both surfaces of the porous substrate on which the electrode adhesive layer is formed, respectively.

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