KR20170015149A - Selective ion adsorbable separator, method for manufacturing the same and electrochemical cell comprising the same - Google Patents

Abstract

The present invention relates to a selective ion adsorbent separator, a method for manufacturing the same, and an electrochemical cell including the same. The separator includes: a porous substrate including a plurality of air gaps; an inorganic coating layer positioned on a surface of the porous substrate, and including inorganic particles; and a polymer electrolyte coating layer disposed on a surface of the inorganic coating layer, and including at least one coating layer selected from the group consisting of a positive polyelectrolyte coating layer, a negative polyelectrolyte coating layer, and a coating layer in which the positive polyelectrolyte coating layer and the negative polyelectrolyte coating layer are laminated alternately. In a battery with a lithium electrode, the separator selectively absorbs only lithium ions and allows the lithium ions to pass therethrough by modifying an inner wall of separator pores so as to increase the Li+ transference number at a lithium electrode interface side, thereby inducing uniform metal plating, which inhibits formation and growth of dendrite.

Description

TECHNICAL FIELD The present invention relates to a selective ion adsorptive separator, a method for producing the same, and an electrochemical cell including the separator. [0001] The present invention relates to a selective ion adsorptive separator,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator, a method of manufacturing the same, and an electrochemical cell including the separator. More particularly, the present invention relates to a separator, the lithium electrode can Li ⁺ transition of the surface side (Li ⁺ transference number) to increase by even metal-plating (plating) induced by dendrite formation, and a separator which are capable of inhibiting the growth, methods for their preparation and electrochemical comprising the same Battery.

The electrochemical cell is composed of a positive electrode and a negative electrode, a separator for separating the negative electrode and the positive electrode, and an electrolyte for relieving the polarization generated during the electrochemical reaction by helping charge transfer And a battery using lithium metal as a negative electrode is generally referred to as a lithium metal battery.

Since the lithium is a metal having high reactivity, the lithium electrode including lithium has a problem of stability that is difficult to handle the electrode itself during the process. When the lithium metal is used as an electrode, lithium dendrites are formed in the charging and discharging process, and the dendrites may short-circuit the battery.

Thus, in the lithium battery applying the lithium electrode, when applying a conventional separator, a liquid electrolyte is impregnated into separator pores Li ⁺ transition number (Li ⁺ transference number) is so Genie a value less than 0.5 is an anion gradient of ions at the electrode interface Resulting in dendrite formation and growth by generating an ion-depletion region.

In order to make the number of lithium ions close to 1 at the conventional lithium electrode interface, a sil-gel ion-conducting polymer was introduced. However, the single ion conductive polymer has very low stability to electrolytes.

Accordingly, research and development of a separator capable of minimizing the interfacial resistance by improving the stability with respect to the electrolyte and improving the contact property between the electrode and the separator are required.

 ECS, 2002, 5, (12) A286 ~ 289, Live Scanning Electron Microscope Observations of Dendritic Growth in Lithium / Polymer Cells

An object of the present invention is to solve the above problems, and it is an object of the present invention to provide a lithium secondary battery which is capable of selectively absorbing and passing only lithium ions through a modification of the inner wall of the separator pore, ^And to provide a separator capable of inducing uniform metal plating by increasing the Li transference number to suppress dendrite formation and growth.

Another object of the present invention is to provide a method of manufacturing the separator.

Still another object of the present invention is to provide an electrochemical cell including the separator.

According to an embodiment of the present invention, there is provided a method of manufacturing a semiconductor device including a porous substrate including a plurality of voids, an inorganic coating layer disposed on a surface of the porous substrate and including inorganic particles, a positive polyelectrolyte disposed on a surface of the inorganic coating layer, The present invention provides a separator comprising a polymer electrolyte coating layer comprising any one coating layer selected from the group consisting of a coating layer, a negative polyelectrolyte coating layer, and an alternately laminated coating layer.

The inorganic coating layer may also be located on the inner surface of the pores of the porous substrate. At this time, the polymer electrolyte coating layer may also be located on the surface of the inorganic coating layer located on the inner surface of the pores of the porous substrate.

The inorganic particles may be at least one selected from the group consisting of SrTiO ₃ , SnO ₂ , CeO ₂ , MgO, NiO, CaO, ZnO, ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , SiC, BaTiO ₃ , _{) O 3 (PZT), Pb} 1-x La x Zr 1-y Ti y O 3 (PLZT, 0 <x <1, 0 <y <1), Pb (Mg 3 Nb 2/3) O 3 -PbTiO _{3 (PMN-PT), HfO} 2, lithium phosphate (Li ₃ PO _4), lithium titanium phosphate _{(Li x Ti y (PO 4} ) 3, 0 <x <2, 0 <y <3), lithium aluminum titanium phosphate (Li _x Al _y Ti _z (PO ₄ ) ₃ , 0 <x <2, 0 <y <1, 0 <z <3), (LiAlTiP) _x O _y series glass <13), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , , 0 <y <1, 0 <z <1, 0 <w <5), lithium nitrides _{(Li x N y, 0 <} x <4, 0 <y <2), SiS 2 (Li x Si y S _{z, 0 <x <3,} 0 <y <2, 0 <z <4) based _{glass, P 2 S 5 (Li} x P y S z, 0 <x <3, 0 <y <3, 0 <z &Lt; 7) series glass, and a mixture thereof.

The inorganic coating layer may include a mixture of the inorganic particles and the binder polymer.

The binder polymer may be at least one selected from the group consisting of polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-co-trichlorethylene, polymethylmethacrylate, Polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyimide, polyethylene oxide (PET), polyvinylpyrrolidone, ), Cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylpolyvinylalcohol, Ethylcellulose (cyanoethylcellulose), cyano But are not limited to, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, polyvinylalcohol, And a mixture thereof.

In the inorganic coating layer, the inorganic particles may be connected and fixed by the binder polymer, and a pore structure may be formed due to an interstitial volume between the inorganic particles.

The polymer electrolyte coating layer may be located on the surface of the pore structure due to the void space between the inorganic particles.

The polymer electrolyte coating layer may include a coating layer in which the cationic polymer electrolyte coating layer and the anion polymer electrolyte coating layer are alternately laminated one or more times.

It is more preferable that the anion polymer electrolyte coating layer is disposed on the outermost surface of the polymer electrolyte coating layer.

The cationic polyelectrolyte coating layer may be formed of any one of poly (allylamine hydrochloride), poly (diallyl dimethylammonium chloride), PDAC, linear poly (ethyleneimine) poly (ethylene imine), branched poly (ethylene imine), polylysine, polyaniline, polypyrrole, chitosan, poly (acrylamide-co Poly (acrylamide-co-diallyldimethylammonium chloride)), and a mixture thereof. The cationic polymer electrolyte according to the present invention may further comprise a cationic polymer electrolyte selected from the group consisting of poly (acrylamide-co-diallyldimethylammonium chloride)

The anionic polyelectrolyte coating layer may be formed of at least one selected from the group consisting of poly (acrylic acid), PAA, poly (styrene sulfonate), PSS, poly (methacrylic acid) Poly (styrene sulfonate), hyaluronic acid, poly (thiophene), poly (glutamic acid), poly (thiophene) Acrylamido-2-methyl-1-propanesulfonic acid-poly (2-acrylamido-2-methyl- Acrylonitrile acrylonitrile, poly (acrylic acid sodium salt), polyanethol (polyvinylpyrrolidone), polyaniline (polyvinylpyrrolidone) Poly (4-styrenesulfonic acid-co-maleic acid) sodium salt, poly (4-styrenesulfonic acid) sodium salt (poly (4-st yrenesulfonic acid lithium salt, poly (4-styrenesulfonic acid) ammonium salt, poly (vinyl sulfate) potassium salt, poly (sodium vinylsulfonate) Poly (vinylsulfonic acid sodium salt), and a mixture thereof. The anionic polyelectrolyte may be selected from the group consisting of poly (vinylsulfonic acid sodium salt) and mixtures thereof.

According to another embodiment of the present invention, there is provided a method for producing a porous polymer electrolyte membrane, comprising the steps of preparing a porous substrate containing a plurality of voids, forming an inorganic coating layer containing inorganic particles on the surface of the porous substrate, forming a polymer electrolyte coating layer comprising a coating layer selected from the group consisting of a positive polyelectrolyte coating layer, a negative polyelectrolyte coating layer, and an alternately laminated coating layer, .

The step of forming the inorganic coating layer may include the steps of preparing a composition for forming an inorganic coating layer by adding the inorganic particles to a solvent, and coating the composition for forming the inorganic coating layer on the surface of the porous substrate.

The step of forming the inorganic coating layer includes the steps of preparing a polymer solution by dissolving the binder polymer in a solvent, adding the inorganic particles to the polymer solution, and coating the inorganic coating layer composition on the surface of the porous substrate Step &lt; / RTI &gt;

In the step of forming the polymer electrolyte coating layer, a composition for forming a cation or anion polymer electrolyte coating layer is prepared by adding a cationic or an anionic polymer electrolyte to a solvent, and the porous substrate is immersed in the composition for forming a cationic or anionic polymer electrolyte coating layer, And forming a cationic or anionic polyelectrolyte coating layer.

A step of immersing the porous substrate in the composition for forming a cationic polymer electrolyte coating layer, a step of immersing the composition in the composition for forming an anionic polyelectrolyte coating layer, and a combination thereof are repeated a plurality of times .

According to another embodiment of the present invention, there is provided an electrochemical cell including a positive electrode and a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the separator is a separator according to an embodiment of the present invention .

The electrochemical cell may be a lithium secondary battery.

The cathode may comprise lithium metal.

The present invention even by increasing the battery applied to a lithium electrode, through modifications of the separator is the pore wall so the separator is capable of selectively absorbing and passing only lithium ions to be Li ⁺ transition of the lithium electrode surface side (Li ⁺ transference number) Metal plating can be induced to suppress dendrite formation and growth.

1 is a schematic view schematically showing one example of a separator according to an embodiment of the present invention.
2 is a graph showing the lithium cycle efficiency measured in Experimental Example 2 of the present invention.
3 is a photograph showing the volume expansion of the separator using a scanning electron microscope in Experimental Example 3 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

The separator according to an embodiment of the present invention includes a porous substrate including a plurality of voids, an inorganic coating layer disposed on the surface of the porous substrate and including inorganic particles, and a positive polyelectrolyte ) Coating layer, an anionic polyelectrolyte coating layer (negative polyelectrolyte coating layer), and a coating layer alternately stacked thereon.

Since the separator includes the inorganic coating layer and the high-molecular-weight electrolyte coating layer, the pore inner wall of the separator is modified so that the separator selectively absorbs only lithium ions and can pass therethrough. Thus, Li ⁺ by increasing the number of transition (Li ⁺ transference number) to induce the uniform metal-plating (plating) can be suppressed dendrite formation and growth.

The porous substrate is not particularly limited in the present invention, and may be in the form of a porous membrane. Specifically, the porous substrate includes any one selected from the group consisting of polyolefin, polyester, polysulfone, polyimide, polyetherimide, polyamide, polytetrafluoroethylene, rayon, glass fiber, Or a multilayer film thereof. More specifically, the porous substrate may be a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer and an ethylene / methacrylate copolymer, Layer or more.

In addition, the porous substrate may have a porosity of 50 to 80% by volume based on the total volume of the porous substrate. If the porosity of the porous substrate is less than 50% by volume, the inorganic coating layer or the polymer electrolyte coating layer in the pores is not sufficiently formed and the improvement effect of the coating layer is insufficient. When the porosity is more than 80% by volume, The battery performance may be deteriorated.

In addition, the porous substrate may include micropores having an average pore diameter (D50) of 1 nm to 200 nm in the porous substrate. If the average pore diameter is 1 nm, the formation of the coating layer is not easy or the effect of improving the coating layer is insignificant. If the average pore diameter exceeds 200 nm, the mechanical strength of the separator itself may decrease.

The inorganic coating layer is located on the surface of the porous substrate.

At this time, the inorganic coating layer may be located on one side, both sides, the inner surface of the porous substrate, or both of them, or may be coated on some or all of them. More specifically, the inorganic coating layer may be provided on both sides of the porous substrate, and more specifically, the inorganic coating layer may surround the entire surface of the porous substrate. Also, considering the improvement effect of the formation of the inorganic coating layer, the inorganic coating layer may be located on both the entire surface of the porous substrate and the inner surface of the void.

The inorganic coating layer includes the inorganic particles.

The inorganic particles 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 battery (for example, 0 to 5 V based on Li / Li ⁺ ). Particularly, when inorganic particles having an ion-transporting ability are used, the ion conductivity in the electrochemical device can be increased and the performance can be improved. Therefore, it is preferable that the ionic conductivity is as high as possible. In addition, when the inorganic particles have a high density, it is difficult to disperse the particles at the time of coating. In addition, in the case of an inorganic substance having a high dielectric constant, dissociation of an electrolyte salt in the liquid electrolyte, for example, a lithium salt, can also be increased, and the ion conductivity of the electrolyte can be improved.

For the reasons stated above, the inorganic particles are preferably high-permittivity inorganic particles having a dielectric constant of 5 or more, preferably 10 or more, inorganic particles having lithium ion-transporting ability, inorganic particles having piezoelectricity, or a mixture thereof Do.

The piezoelectricity material refers to a nonconductor at normal pressure or a material having electrical conductivity due to a change in internal structure when a certain pressure is applied. The piezoelectricity material exhibits a high permittivity with a dielectric constant of 100 or more, And when charged or tensioned or compressed, charges are generated so that one surface is charged positively and the other surface is charged negatively, thereby forming an electric potential difference between both surfaces.

When the inorganic particles having the above-described characteristics are used as the inorganic coating layer component, if an internal short circuit of the positive electrode and the negative electrode occurs due to an external impact such as local crush or nail, Not only the negative electrode is directly contacted but also the potential difference in the particle is generated due to the piezoelectricity of the inorganic particles. As a result, the electrons move between the anode and the cathode, that is, the minute current flows, The safety can be improved. Examples of the inorganic particles having piezoelectricity include BaTiO ₃ , Pb (Zr, Ti) O ₃ (PZT), Pb _{1 -x} La _x Zr _{1 -y} Ti _y O ₃ (PLZT, 0 < 0 <y <1), Pb (Mg ₃ Nb _2/3 ) O ₃ -PbTiO ₃ (PMN-PT) hafnia, HfO ₂ and mixtures thereof .

The inorganic particles having a lithium ion transferring ability include inorganic particles having lithium ion-containing ability but not lithium and having a function of moving lithium ions, wherein the inorganic particles having lithium ion transferring ability have a particle structure It is possible to transfer and move lithium ions due to a kind of defect existing therein, so that the lithium ion conductivity in the battery is improved and the battery performance can be improved. Examples of the inorganic particles having lithium ion transferring ability include lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0 <x <2, 0 <y < (Li _x Al _y Ti _z (PO ₄ ) ₃ , 0 <x <2, 0 <y <1, 0 <z <3), 14Li ₂ O-9Al ₂ O ₃ -38TiO ₂ -39P ₂ O ₅ as such (LiAlTiP) _x O _y series glass (0 <x <4, 0 <y <13), lithium lanthanum titanate _{(Li x La y TiO 3,} 0 <x <2, 0 <y <3 _{), Li 3.25 Ge 0.25 P 0.75} S 4 lithium germanate Mani help thiophosphate _{(Li x Ge y P z S} w, 0 <x <4, 0 <y <1, 0 <z <1, 0 <w , such as < 5), Li ₃ N lithium nitride _{(Li x N y, 0 <} x <4, 0 <y <2), Li 3 PO 4 SiS 2 family, such as _{-Li 2 S-SiS 2 glass (} Li x such as _{Si y S z, 0 <x} <3, 0 <y <2, 0 <z <4), LiI-Li 2 SP 2 S 5 P 2 S 5 based glass (Li _x P _y S _z, such as 0 < x <3, 0 <y <3, 0 <z <7), and mixtures thereof.

Examples of the inorganic particles having a dielectric constant of 5 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 , SiO ₂ , SiC, and mixtures thereof. When the above-mentioned high-permittivity inorganic particles, the inorganic particles having piezoelectricity, and the inorganic particles having lithium ion transferring ability are mixed, their synergistic effect can be doubled.

The separator can form the pore structure of the inorganic coating layer together with the pores included in the porous substrate by controlling the size of the inorganic particles, the content of the inorganic particles, and the composition ratio of the inorganic particles. The pore size and porosity Can be adjusted together.

The size of the inorganic particles is not limited, but is preferably in the range of 0.001 to 10 mu m for the formation of a film of uniform thickness and a suitable porosity. If the size of the inorganic particles is less than 0.001 탆, the dispersibility of the inorganic particles may be lowered and the physical properties of the inorganic coating layer may be difficult to control. If the size of the inorganic particles exceeds 10 탆, the thickness of the separator may be increased, And an excessively large pore size may increase the probability of an internal short circuit occurring during charging and discharging of the battery.

Meanwhile, the inorganic coating layer may include a mixture of the inorganic particles and the binder polymer. That is, the inorganic coating layer may further include the binder polymer together with the inorganic particles.

The binder polymer is not particularly limited in the present invention, and a binder polymer having a low glass transition temperature (Tg) may be used, and preferably, the binder polymer is in the range of -200 to 200 ° C. This is because mechanical properties such as flexibility and elasticity of the produced separator can be improved. The binder polymer faithfully performs a binder function to connect and stably fix the inorganic particles and particles, the surface of the porous substrate, and a part of the pores of the porous substrate with the inorganic particles, It is possible to prevent degradation.

In addition, although the binder polymer does not necessarily have ion conductivity, the performance of the electrochemical device can be further improved by using a polymer having ion conductivity. Therefore, it is preferable that the binder polymer has a high permittivity constant.

In fact, since the degree of dissociation of the salt in the electrolyte depends on the permittivity constant of the electrolyte solvent, the higher the permittivity constant of the binder polymer, the better the salt dissociation in the electrolyte. The dielectric constant of the binder polymer may be in the range of 1.0 to 100 (measurement frequency = 1 kHz), preferably 10 or more.

In addition to the functions described above, the binder polymer may be gelled upon impregnation with a liquid electrolyte to exhibit a high degree of swelling of the electrolyte. In fact, when the binder polymer is a polymer having an excellent electrolyte impregnation rate, the electrolyte injected after assembling the battery is impregnated with the polymer, and the polymer having the absorbed electrolyte has the ability to conduct electrolyte ions. Therefore, the performance of the electrochemical device can be improved as compared with the conventional separator. In addition, compared with the conventional hydrophobic polyolefin-based separator, wettability with respect to an electrolyte for a battery is improved, and a polar electrolyte for a battery, which has been conventionally difficult to use, can be applied. In addition, when the binder polymer is a polymer that can be gelled upon electrolyte impregnation, the gel electrolyte may be formed by reacting the injected electrolyte with the polymer to form a gelled separator. The electrolyte thus formed is easier to manufacture than the conventional gel type electrolyte, and exhibits high ion conductivity and electrolyte impregnation rate, thereby improving the performance of the battery. Therefore, if possible, a polymer having a solubility index of 15 to 45 MPa ^1/2 is preferable, and a range of 15 to 25 MPa ^1/2 and 30 to 45 MPa ^1/2 is more preferable. If the solubility index is less than 15 MPa &lt; ^1/2 &gt; and more than 45 MPa &lt; ^1/2 &gt;, it may be difficult to swell by a conventional battery liquid electrolyte.

Non-limiting examples of usable binder polymers include polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichlorethylene, Polyolefins such as polymethylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyimide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolylane, Vinyl alcohol (cyanoethylpolyvinylalcohol), cyanoethylcellulose But are not limited to, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, , Polyvinyl alcohol, and mixtures thereof. The term &quot; polyvinyl alcohol &quot; In addition, any material including the above-mentioned characteristics may be used alone or in combination.

When the inorganic coating layer further comprises the polymer binder, the content of the inorganic particles is not particularly limited, but is preferably 50 to 99% by weight, more preferably 60 to 95% by weight based on the total weight of the inorganic coating layer. More preferable. If the content of the inorganic particles is less than 50% by weight, the content of the binder polymer becomes excessively large, and the pore size and porosity due to the reduction of the void space formed between the inorganic particles may be decreased, If the content of the binder polymer is more than 99% by weight, the mechanical properties of the final separator may be deteriorated due to the weak adhesion between the inorganic particles because the content of the binder polymer is too small.

In the inorganic coating layer, the composition ratio of the inorganic particles and the binder polymer is not particularly limited, but it is adjustable within a weight ratio of 10:90 to 99: 1, and preferably a weight ratio of 80:20 to 99: 1. When the content of the inorganic particles is less than 10:90 by weight, the content of the binder polymer becomes excessively large, resulting in a reduction in pore size and porosity due to a decrease in void space formed between the inorganic particles, If the content of the inorganic particles is more than 99: 1 by weight, the binder polymer may be too low in the mechanical strength of the final separator due to the weak adhesion between the inorganic particles.

The inorganic coating layer may further include other commonly known additives in addition to the inorganic particles and the binder polymer.

In the inorganic coating layer, the inorganic particles are connected and fixed by the binder polymer, and a pore structure due to the interstitial volume between the inorganic particles is formed.

The pore size and porosity of the inorganic coating layer mainly depend on the size of the inorganic particles. For example, when inorganic particles having a particle size of 1 μm or less are used, pores formed also show 1 μm or less. The surface of such a pore structure can also be coated by the polymer electrolyte coating layer described later, and in this case, the effect of forming the polymer electrolyte coating layer can be doubled.

The thickness of the inorganic coating layer is not particularly limited, but is preferably in the range of 0.01 to 100 mu m. The pore size and porosity of the inorganic coating layer are preferably 0.001 to 10 탆 and 5 to 95%, respectively, but the present invention is not limited thereto.

Accordingly, the final pore size and porosity of the separator including the inorganic coating layer and the polymer electrolyte coating layer are preferably 0.001 to 10 탆 and 5 to 95%, respectively. The thickness of the separator is not particularly limited and can be appropriately adjusted in consideration of battery performance. The thickness of the separator is preferably in the range of 1 to 100 mu m, more preferably in the range of 1 to 30 mu m.

In addition, when the inorganic coating layer includes the inorganic particles and the binder polymer, a plurality of uniform pore structures are formed on both the inorganic coating layer and the porous substrate, and the lithium ions are smoothly moved through the pores, The electrolyte of the battery can be filled with a high impregnation rate, so that the performance of the battery can be improved at the same time.

Also, since the conventional polyolefin-based separator has a melting point of 120 to 140 ° C, heat shrinkage occurs at a high temperature. However, the separator having the inorganic particles and the binder polymer in the inorganic coating layer is not thermally shrunk due to heat resistance of the inorganic particles. Therefore, in the electrochemical device using the separator, even if the separator ruptures in the battery due to an excessive condition due to internal or external factors such as high temperature, overcharging, external impact, etc., the anode is not easily short-circuited by the inorganic coating layer, It is possible to prevent the short-circuited area from greatly expanding, thereby improving the safety of the battery.

On the other hand, the polymer electrolyte coating layer is located on the surface of the inorganic coating layer.

At this time, the polymer electrolyte coating layer is located on the surface of the inorganic coating layer and may be formed at any position where the inorganic coating layer is located. That is, the porous substrate may be located on one side, both sides, the inner surface of the cavity, or both, and may be coated on some or all of them. Also, the surface of the pore structure due to the void space between the inorganic particles of the inorganic coating layer may be coated with the polymer electrolyte coating layer.

The polyelectrolyte coating is a metal-play even by increasing the separator are lithium ion only be optionally Li ⁺ metastasis makes it possible to absorb and pass through the lithium electrode surface side of the (Li ⁺ transference number) through a modification of the separator pores inside wall Ting thereby inducing plating and thereby inhibiting dendrite formation and growth.

On the other hand, when the porous substrate contains a hydrophobic substance such as polyolefin, the wettability with the aqueous solution is poor. In order to form the polymer electrolyte coating layer, the wettability of the porous substrate is improved through oxygen (O ₂ ) However, in the case of the present invention, since the wettability of the porous substrate is improved by the inorganic coating layer, the polymer electrolyte coating layer may be formed without further constitution and process for improving the wettability of the plasma treatment or the like There are advantages to be able to.

The polymer electrolyte coating layer includes the cationic polymer electrolyte coating layer or the anionic polymer electrolyte coating layer, or alternatively includes a coating layer alternately laminated. When the polymer electrolyte coating layer includes a coating layer in which the cationic polymer electrolyte coating layer and the anion polymer electrolyte coating layer are alternately stacked, the cationic polymer electrolyte coating layer and the anion polymer electrolyte coating layer may be alternately laminated at least once. That is, the polymer electrolyte coating layer may include the cationic polymer electrolyte coating layer or the anionic polymer electrolyte coating layer, respectively, and the cationic polymer electrolyte coating layer and the anionic polymer electrolyte coating layer may be respectively only one layer, The cationic polymer electrolyte coating layer and the anionic polymer electrolyte coating layer may be alternately stacked including the polymer electrolyte coating layer and a plurality of the anionic polymer electrolyte coating layers.

At this time, the anion polymer electrolyte coating layer is preferably disposed on the outermost surface of the polymer electrolyte coating layer. When the anionic polymer electrolyte coating layer is disposed on the outermost surface of the polymer electrolyte coating layer, the surface of the separator and the inner wall of the gap have a negative charge, so that the separator selectively absorbs only lithium ions and can pass therethrough and it may be able to induce the transition of the number of Li ⁺ lithium electrode interface side (Li ⁺ transference number) metal-play even by increasing the plated (plating) can suppress dendrite formation and growth.

The cationic polymer electrolyte coating layer may contain -NR ⁴⁺ ions. The R may be hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms .

As a specific example, the cationic polymer electrolyte coating layer may be formed of at least one selected from the group consisting of poly (allylamine hydrochloride), poly (diallyl dimethylammonium chloride) (PDAC), linear poly (ethyleneimine hydrochloride) poly (ethylene imine), branched poly (ethylene imine), polylysine, polyaniline, polypyrrole, chitosan, poly (ethylene imine) Amide-co-diallyldimethylammonium chloride), poly (acrylamide-co-diallyldimethylammonium chloride), and mixtures thereof.

The anionic polyelectrolyte coating is -COO ^- or -SO may include ^3- ion. For example, the anionic polyelectrolyte coating layer may be formed of at least one selected from the group consisting of poly (acrylic acid), PAA, poly (styrene sulfonate), PSS, poly (methacrylic acid) ), Poly (glutamic acid), poly (thiophene), poly (styrenesulfonate), poly (styrene sulfonate), hyaluronic acid, Poly (2-acrylamido-2-methyl-1-propanesulfonic acid), poly (2-acrylamido-2-methyl- Acrylonitrile acrylate, poly (acrylic acid sodium salt), poly (acrylic acid sodium salt), polyacrylic acid, Polyanetholesulfonic acid sodium salt, poly (4-styrenesulfonic acid-co-maleic acid) sodium salt, poly (4-styrenesulfonic acid) sodium salt, ) (4-styrenesulfonic acid) ammonium salt, poly (4-styrenesulfonic acid) lithium salt, poly (4-styrenesulfonic acid) ), Poly (vinylsulfonic acid sodium salt), and a mixture thereof. The anionic polyelectrolyte may be selected from the group consisting of poly (vinylsulfonic acid sodium salt), poly (vinylsulfonic acid sodium salt) and mixtures thereof.

1 is a schematic view schematically showing one example of the separator.

1, the separator 100 includes a porous substrate 10 including a plurality of voids, an inorganic coating layer 20 disposed on the surface of the porous substrate 10 and containing inorganic particles, And a polymer electrolyte coating layer 30 disposed on the surface of the coating layer 20 and alternately stacking a cationic polymer electrolyte coating layer 31 and an anion polymer electrolyte coating layer 32. At this time, a negative electrode (not shown) may be disposed on the anionic polyelectrolyte coating layer 32, and an anode (not shown) may be disposed on the porous substrate 10 side.

In the case of directly coating the polymer electrolyte coating layer 30 on the porous substrate 10, since there is a limit to the coating of the polymer electrolyte which directly charges, the inorganic coating layer 20 is formed, The polymer electrolyte coating layer 30 may be formed on the polymer electrolyte membrane 20.

In addition, in the case of the general olefin-based porous substrate, since the surface of the porous substrate is made porous, it is difficult to coat the surface completely. On the other hand, in the case of the porous substrate 10 on which the inorganic coating layer 20 is formed, it is easy to form the polymer electrolyte coating layer 30 on the inorganic coating layer 20.

Since the inorganic coating layer 20 is densely coated on the porous substrate 10, the polymer electrolyte for forming the polymer electrolyte coating layer 30 can be uniformly coated on the surface of the inorganic coating layer 20, Thus, the charge of the inner wall of the small pores of the inorganic coating layer 20 can be controlled.

According to another aspect of the present invention, there is provided a method of manufacturing a separator, comprising: forming an inorganic coating layer containing inorganic particles on a surface of a porous substrate including a plurality of voids; and forming a positive polyelectrolyte ) Coating layer, a negative polyelectrolyte coating layer, and a coating layer alternately stacked on the polymer electrolyte layer.

First, an inorganic coating layer containing inorganic particles is formed on the surface of the porous substrate containing a plurality of voids.

The method of forming a plurality of microvoids in the porous substrate is not particularly limited in the present invention and may be a method that is commonly used in the art. For example, it is possible to use a wet method or a dry method. However, in the wet method, the thickness of the porous substrate can be controlled thinner and uniformly than in the dry method, the size of the generated pores can be uniformly controlled, It is possible to produce an excellent porous substrate.

In order to form the inorganic coating layer, the inorganic particles are first added to a solvent to prepare a composition for forming an inorganic coating layer.

As the solvent to which the inorganic particles are added, the solubility index is similar to that of the inorganic particles to be used, and the boiling point is preferably low. This is to facilitate uniform mixing and subsequent solvent removal. Non-limiting examples of usable solvents include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone ( N-methyl-2-pyrrolidone, NMP), cyclohexane, water or a mixture thereof.

After the inorganic particles are added to the solvent, the inorganic particles can be crushed. In this case, the crushing time is preferably 1 to 20 hours, and the particle size of the crushed inorganic particles is preferably 0.001 to 10 탆 as mentioned above. As the crushing method, a conventional method can be used, and a ball mill method is particularly preferable.

Meanwhile, in the case of preparing an inorganic coating layer containing a mixture of the inorganic particles and the binder polymer, the step of preparing the composition for forming an inorganic coating layer may include preparing a polymer solution by dissolving the binder polymer in a solvent, And adding inorganic particles to the polymer solution to prepare a composition for forming an inorganic coating layer.

Specifically, the binder polymer is first dissolved in an appropriate organic solvent to prepare a polymer solution. It is preferable that the solvent has a solubility index similar to that of the binder polymer to be used and a low boiling point. Non-limiting examples of usable solvents include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone ( N-methyl-2-pyrrolidone, NMP), cyclohexane, water or a mixture thereof.

The composition for forming an inorganic coating layer may be prepared by adding and dispersing the inorganic particles to the polymer solution. At this time, after the inorganic particles are added to the polymer solution, the inorganic particles may be crushed. The composition of the inorganic coating layer composition composed of the inorganic particles and the binder polymer is not particularly limited and can be appropriately adjusted according to the thickness, pore size, and porosity of the finally produced separator.

For example, as the weight ratio (ratio = I / P) of the inorganic particles (I) to the binder polymer (P) is increased, the porosity of the separator increases and the same solid content (weight of inorganic particles + Resulting in an increase in the thickness of the separator. In addition, since the pores of the inorganic particles increase, the pore size increases. At this time, since the interstitial distance between the inorganic particles increases as the size (particle size) of the inorganic particles increases, .

Next, the inorganic coating layer can be prepared by coating the prepared composition for forming an inorganic coating layer on the prepared porous substrate and then drying the composition.

The inorganic coating layer forming composition may be coated on the porous substrate by a conventional coating method known in the art. For example, a dip coating, a die coating, a roll coating, Various methods such as comma coating or mixing method thereof can be used.

At this time, when the composition for forming an inorganic coating layer is coated on the porous substrate, it may be coated on both sides of the porous substrate, or may be selectively coated on only one side.

Finally, a polymer electrolyte coating layer including a coating layer selected from the group consisting of a cationic polymer electrolyte coating layer, an anion polymer electrolyte coating layer, and alternately laminated coating layers is formed on the surface of the inorganic coating layer.

Specifically, in the step of forming the polymer electrolyte coating layer, the cation or anion polymer electrolyte is added to a solvent to prepare a composition for forming a cationic or anionic polymer electrolyte coating layer, and the porous substrate is coated with a composition for forming the cationic or anionic polymer electrolyte coating layer To form the cationic or anionic polymer electrolyte coating layer.

The solvent for dissolving the cationic polymer electrolyte or the anionic polymer electrolyte is not particularly limited as long as it can dissolve the cationic polymer electrolyte or the anionic polymer electrolyte. Examples of the solvent include water, tetrahydrofuran (THF) , An ether solvent generally used as an electrolyte, or a carbonate solvent can be used.

The amount of the cationic polymer electrolyte or the anionic polymer electrolyte to be added to the solvent can be appropriately adjusted according to the immersion conditions such as the immersion process time and the like.

Next, the porous substrate may be immersed in the composition for forming the cation or anion polymer electrolyte coating layer for a predetermined time to form the cation or anion polymer electrolyte coating layer on the surface of the inorganic coating layer. At this time, the immersion process may be performed at room temperature (20 to 30 ° C) without particular limitation, and the time of the immersion process may be suitably controlled according to the cation or anionic polymer electrolyte, and is preferably 1 to 20 minutes, 5 to 10 minutes.

At this time, in order to form a polymer electrolyte coating layer in which the cationic polymer electrolyte coating layer and the anionic polymer electrolyte coating layer are alternately laminated, the porous base material is alternately applied to the composition for forming a cationic polymer electrolyte coating layer and the composition for forming an anionic polymer electrolyte coating, (Times).

As described above, conventionally, the polymer electrolyte coating layer is formed after the wettability of the porous substrate is improved through oxygen (O ₂ ) plasma treatment or the like in order to form the polymer electrolyte coating layer. However, in the present invention, As the wettability of the porous substrate is improved by the inorganic coating layer, the polymer electrolyte coating layer can be formed without further constitution and process for improving wettability such as plasma treatment.

Specifically, when the above-described polymer electrolyte coating layer is formed on a general olefin-based porous substrate, plasma treatment is performed because there is a limit to the polymer electrolyte coating that directly charges. Even so, since the porous substrate has pores of several hundred nanometers or more, the portion coated with the polymer electrolyte may be limited, and even if the porous substrate is coated, pores of several hundred nanometers or more are continuously present There is a limit to obtaining an ion selectivity improving effect at the interface with the lithium metal electrode. On the other hand, although the thickness of the polymer electrolyte coating layer can be formed by further carrying out an immersion cycle, in this case, the ion selective effect can be reduced by neutralization of the charge. On the other hand, in the present invention, as the inorganic coating layer is formed, since the inorganic particles are densely coated on the general olefin-based porous substrate, the polymer electrolyte can be uniformly coated on the surface of the inorganic particles, The effect of which can be excellently exerted.

However, in the case of the present invention, the wettability of the porous substrate may be further improved through the plasma treatment, and then the polymer electrolyte coating layer may be formed.

The plasma treatment may be performed according to a conventional method, specifically, by treating with an oxygen plasma for 5 to 120 minutes.

The electrochemical cell according to another embodiment of the present invention includes the above-described separator.

The electrochemical device includes all devices that perform an electrochemical reaction, and specific examples thereof include all kinds of primary, secondary, fuel cell, solar cell, and capacitor. In particular, the secondary battery is preferably a lithium battery, and examples thereof include non-limiting examples of the lithium secondary battery, .

The lithium battery is not particularly limited and may be classified into a cylindrical type, a rectangular type, a coin type, a pouch type, and the like depending on the form, and may be divided into a bulk type and a thin type depending on the size. .

Specifically, the lithium battery according to an embodiment of the present invention includes an anode, a cathode, and the separator positioned between the anode and the cathode, wherein the inorganic coating layer and the polymer electrolyte coating layer are provided on the separator. Can face the cathode side of the lithium battery.

Further, in the lithium battery, a lithium electrode may be used as a cathode of the lithium battery.

Wherein the lithium electrode comprises lithium as an active material, and the lithium is lithium metal; Lithium metal alloy; Or in the form of a complex of lithium and at least one selected from the group consisting of coke, activated carbon, graphite, graphitized carbon, carbon nanotubes, graphine and carbon, .

In addition, the lithium electrode may be prepared by mixing an additive such as a binder, a conductive material, a dispersant, and the like in a solvent in addition to lithium, and then coating the collector with a current collector and drying the lithium electrode.

At this time, the current collector may be a foil formed of a combination of copper, nickel, etc. and alloys thereof. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the negative electrode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

In addition, the binder is a component that assists in binding of the negative electrode active material and the conductive material to the negative electrode collector, and may be selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, Polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, fluorocarbon rubber, various copolymers thereof, etc. .

The conductive material is a component for further improving the conductivity of the electrode active material. The conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, and examples thereof include natural graphite, artificial graphite, and the like Graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskers such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

In the lithium battery, the positive electrode may be a positive electrode active material coated on the positive electrode collector. The cathode active material may be a conventional material used as a cathode active material of a secondary battery. Examples of the cathode active material include LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li (Ni _a Co _b Mn _c ) O ₂ It may be (a, b, c is a, a + b + c = from 0 to 1, respectively 1), LiFePO _4, or one or more mixtures thereof. The cathode current collector may be a foil or the like made of a combination of aluminum, nickel, etc., and one or more of these alloys.

The lithium battery as described above can be produced by a conventional method, except that it includes the separator described above.

As described above, since the lithium battery including the separator according to the present invention stably exhibits excellent discharge capacity, cycle life characteristics, and efficiency characteristics, it can be used in portable devices such as mobile phones, notebook computers, digital cameras, camcorders, (HEV), plug-in HEV (PHEV), and medium-to-large-sized energy storage systems.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. However, the following embodiments are intended to illustrate the invention, but the invention is not limited thereto.

[Preparation Example 1: Production of separator]

(Example 1)

1) Inorganic coating layer formation

A polymer solution was prepared by adding about 5% by weight of polyvinylidene fluoride-chlorotrifluoroethylene copolymer (PVdF-CTFE) polymer to acetone and dissolving at a temperature of 50 ° C for about 12 hours or longer. The BaTiO ₃ powder was added to the polymer solution so that the ratio was BaTiO ₃ / PVdFCTFE = 90/10 (weight ratio), and the BaTiO ₃ powder was crushed and pulverized for 12 hours or longer using a ball mill method to prepare a slurry. At this time, BaTiO ₃ particle size of the slurry was pulverized to about 400 nm to prepare a slurry.

The slurry thus prepared was coated on a polyethylene porous substrate (porosity of 45%) having a thickness of about 18 탆 by a dip coating method, and the coating thickness was adjusted to about 3 탆. As a result of measurement with a porosimeter, the pore size and porosity in the inorganic coating layer coated on the polyethylene porous substrate were 0.5 탆 and 58%, respectively.

2) Polymer electrolyte coating layer formation

The porous substrate on which the inorganic coating layer was formed was immersed in a solution of positively charged poly (allylamine hydrochloride) (PAH) / H ₂ O (1 mg / mL) as a cationic polymer electrolyte for 10 minutes, and then taken out and washed with water for 1 minute.

The porous substrate was dried naturally for 12 hours and vacuum-dried at room temperature for 12 hours to prepare a separator.

(Example 2)

The separator prepared in Example 1 was immersed in a solution of negatively charged poly (acrylic acid) (PAA) / H ₂ O (1 mg / mL) as an anionic polymer electrolyte for 10 minutes, and then taken out and washed with water for 1 minute.

The separator was dried naturally for 12 hours and vacuum-dried at room temperature for 12 hours to prepare a separator.

(Comparative Example 1)

A separator was produced in the same manner as in Example 1 except that the polyethylene porous substrate used in Example 1 was used and the inorganic coating layer and the polymer electrolyte coating layer were not formed.

(Comparative Example 2)

A separator was produced in the same manner as in Example 1 except that the polyethylene porous substrate on which the inorganic coating layer was formed was used in Example 1 and the polymer electrolyte coating layer was not formed.

(Comparative Example 3)

A polyethylene porous substrate (porosity of 45%) having a thickness of about 18 탆 was prepared, and then subjected to sonication cleaning with ethanol and water for 5 minutes each. The polyethylene porous substrate dried with a nitrogen stream was subjected to UVO plasma treatment for 15 minutes.

The plasma-treated porous substrate was immersed in a solution of positively charged poly (allylamine hydrochloride) (PAH) / H ₂ O (1 mg / mL) as a cationic polymer electrolyte for 10 minutes, and then taken out and washed with water for 1 minute. The porous substrate was subjected to natural drying for 12 hours and vacuum drying at room temperature for 12 hours to form a cationic polymer electrolyte coating layer.

The porous substrate on which the cationic polymer electrolyte coating layer was formed was immersed in a solution of negatively charged poly (acrylic acid) (PAA) / H ₂ O (1 mg / mL) as an anionic polymer electrolyte for 10 minutes, and then taken out and washed with water for 1 minute. The porous substrate was subjected to natural drying for 12 hours and vacuum drying at room temperature for 12 hours to form an anionic polyelectrolyte coating layer.

[Preparation Example 2: Preparation of lithium symmetric cell]

A lithium symmetric cell was prepared using the separator prepared in the above Examples and Comparative Examples.

Specifically, lithium having a thickness of 20 탆 was used as the working electrode and the counter electrode, and the separator prepared in the above example and comparative example was used. The electrolyte injected in this example was tetraglyme: 1,3-dioxolane: 1 M LiFSI and 1 wt% LiNO ₃ were dissolved in a 1: 1: 1 volume ratio of tetraglyme (1,3-dioxolane: dimethoxyethane).

[Experimental Example 1: Measurement of water contact angle]

The water contact angles of the separators prepared in the Examples and Comparative Examples were measured, and the results are shown in Table 1.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Water contact angle (°) About 70 20 20-25 50 to 60 About 20 to 30

As shown in Table 1, it was found that the surface of the polyethylene porous substrate of Comparative Example 1 was hydrophobic and thus it was difficult to form the polymer electrolyte coating layer. However, the porous porous substrate of Comparative Example 2 having the inorganic coating layer formed on the polyethylene porous substrate The water contact angle is lowered to form the polymer electrolyte coating layer.

In the case of Example 1, the cation polymer electrolyte coating layer was formed on the surface of the porous substrate having the inorganic coating layer of Comparative Example 2, and thus the water contact angle was increased. In Example 2, the cation polymer electrolyte coating layer It can be seen that the water contact angle is decreased again as the anionic polymer electrolyte coating layer is formed on the surface of the porous substrate formed with the anion polymer electrolyte. It can be seen from this that the coating layer of each layer is well formed.

[Experimental Example 2: Lithium Efficiency Measurement]

Was calculated on the lithium cycle efficiency and Li ⁺ can transition (Li ⁺ transference number) from the number of charge-discharge cycles indicated in the current (current) of 5.5 mAh with respect to the lithium symmetrical cell was prepared in Preparative Example 2, respectively, and the results 2 And Table 2.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Li ⁺ transition number 0.30 to 0.45 0.35-0.50 0.30-0.50 0.30-0.50 0.55-0.65

Referring to FIG. 2 and Table 2, it can be seen that the lithium cycle efficiency and the Li ⁺ transition number are the highest in the case of the separator of Example 2 in which the anion polymer electrolyte coating layer is formed on the outermost surface.

[Experimental Example 3: Comparison of volume expansion]

The lithium symmetry cells prepared using the separators prepared in Comparative Examples 1 and 2 were subjected to full deposition at 0.1 C and 10% DOD, and the separator was observed with a scanning electron microscope. The results are shown in FIG. 3 .

3, in the separator manufactured in Comparative Example 1, the electrode volume expansion occurred while the dendrite was growing, and the phenomenon in which the separator was pressed by the internal pressure of the cell was observed, while the separator manufactured in Example 2 was lithium Since the volume expansion was comparatively small as it grew relatively uniformly at this interface, there was no phenomenon of being pressed by the pressure.

That is, a separator prepared in Example 2, the separator is uniform by increasing the lithium ion only can be selectively absorbed and passed by the number of Li ⁺ transition of the lithium electrode surface side (Li ⁺ transference number) through a modification of the pore inner wall It was confirmed that metal plating could be induced to suppress dendrite formation and growth.

100: Separator
10: Porous substrate
20: inorganic coating layer
30: Polymer electrolyte coating layer
31: Cationic polymer electrolyte coating layer
32: Anionic polymer electrolyte coating layer

Claims (19)

A porous substrate comprising a plurality of voids,
An inorganic coating layer positioned on the surface of the porous substrate and containing inorganic particles,
A polymer electrolyte coating layer disposed on the surface of the inorganic coating layer and including a coating layer selected from the group consisting of a positive polyelectrolyte coating layer, an anionic polyelectrolyte coating layer, and alternately laminated coating layers,
. The method according to claim 1,
The inorganic coating layer is also located on the inner surface of the void of the porous substrate,
Wherein the polymer electrolyte coating layer is also located on the surface of the inorganic coating layer located on the inner surface of the void of the porous substrate. The method according to claim 1,
The inorganic particles may be at least one selected from the group consisting of SrTiO ₃ , SnO ₂ , CeO ₂ , MgO, NiO, CaO, ZnO, ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , SiC, BaTiO ₃ , _{) O 3 (PZT), Pb} 1-x La x Zr 1-y Ti y O 3 (PLZT, 0 <x <1, 0 <y <1), Pb (Mg 3 Nb 2/3) O 3 -PbTiO _{3 (PMN-PT), HfO} 2, lithium phosphate (Li ₃ PO _4), lithium titanium phosphate _{(Li x Ti y (PO 4} ) 3, 0 <x <2, 0 <y <3), lithium aluminum titanium phosphate (Li _x Al _y Ti _z (PO ₄ ) ₃ , 0 <x <2, 0 <y <1, 0 <z <3), (LiAlTiP) _x O _y series glass <13), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , , 0 <y <1, 0 <z <1, 0 <w <5), lithium nitrides _{(Li x N y, 0 <} x <4, 0 <y <2), SiS 2 (Li x Si y S _{z, 0 <x <3,} 0 <y <2, 0 <z <4) based _{glass, P 2 S 5 (Li} x P y S z, 0 <x <3, 0 <y <3, 0 <z &Lt; 7) series glass, and mixtures thereof. The method according to claim 1,
Wherein the inorganic coating layer comprises a mixture of the inorganic particles and the binder polymer. 5. The method of claim 4,
The binder polymer may be at least one selected from the group consisting of polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-co-trichlorethylene, polymethylmethacrylate, Polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyimide, polyethylene oxide (PET) ), Cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylpolyvinylalcohol, Ethylcellulose (cyanoethylcellulose), cyano But are not limited to, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, polyvinylalcohol, And mixtures thereof. &Lt; Desc / Clms Page number 13 &gt; 5. The method of claim 4,
Wherein the inorganic coating layer is formed such that the inorganic particles are connected and fixed by the binder polymer and a pore structure is formed due to an interstitial volume between the inorganic particles. The method according to claim 6,
Wherein the polymer electrolyte coating layer is also located on the surface of the pore structure due to the void space between the inorganic particles. The method according to claim 1,
Wherein the polymer electrolyte coating layer is formed by alternately laminating the cationic polymer electrolyte coating layer and the anion polymer electrolyte coating layer at least once. The method according to claim 1,
Wherein an anionic polymer electrolyte coating layer is disposed on an outermost surface of the polymer electrolyte coating layer. The method according to claim 1,
The cationic polyelectrolyte coating layer may be formed of any one of poly (allylamine hydrochloride), poly (diallyl dimethylammonium chloride), PDAC, linear poly (ethyleneimine) poly (ethylene imine), branched poly (ethylene imine), polylysine, polyaniline, polypyrrole, chitosan, poly (acrylamide-co (Poly (acrylamide-co-diallyldimethylammonium chloride)), and mixtures thereof. The separator according to claim 1, wherein the cationic polymer electrolyte is selected from the group consisting of poly (acrylamide-co-diallyldimethylammonium chloride) The method according to claim 1,
The anionic polyelectrolyte coating layer may be formed of at least one selected from the group consisting of poly (acrylic acid), PAA, poly (styrene sulfonate), PSS, poly (methacrylic acid) Poly (styrene sulfonate), hyaluronic acid, poly (thiophene), poly (glutamic acid), poly (thiophene) Acrylamido-2-methyl-1-propanesulfonic acid-poly (2-acrylamido-2-methyl- Acrylonitrile acrylonitrile, poly (acrylic acid sodium salt), polyanethol (polyvinylpyrrolidone), polyaniline (polyvinylpyrrolidone) Poly (4-styrenesulfonic acid-co-maleic acid) sodium salt, poly (4-styrenesulfonic acid) sodium salt (poly (4-st yrenesulfonic acid lithium salt, poly (4-styrenesulfonic acid) ammonium salt, poly (vinyl sulfate) potassium salt, poly (sodium vinylsulfonate) Poly (vinylsulfonic acid sodium salt), and mixtures thereof. The separator according to claim 1, wherein the anionic polymer electrolyte is selected from the group consisting of poly (vinylsulfonic acid sodium salt) and mixtures thereof. Forming an inorganic coating layer containing inorganic particles on the surface of the porous substrate containing a plurality of voids, and
Forming a polymer electrolyte coating layer on the surface of the inorganic coating layer, the coating layer being selected from the group consisting of a positive polyelectrolyte coating layer, a negative polyelectrolyte coating layer, and alternately laminated coating layers;
Wherein the separator is made of a metal. 13. The method of claim 12,
The step of forming the inorganic coating layer
Adding the inorganic particles to a solvent to prepare a composition for forming an inorganic coating layer, and
Coating the composition for forming an inorganic coating layer on the surface of the porous substrate
Wherein the separator is made of a metal. 13. The method of claim 12,
The step of forming the inorganic coating layer
Dissolving the binder polymer in a solvent to prepare a polymer solution,
Adding the inorganic particles to the polymer solution to prepare a composition for forming an inorganic coating layer, and
Coating the composition for forming an inorganic coating layer on the surface of the porous substrate
Wherein the separator is made of a metal. 13. The method of claim 12,
The step of forming the polymer electrolyte coating layer
A cation or an anionic polymer electrolyte is added to a solvent to prepare a composition for forming a cationic or anionic polymer electrolyte coating layer and the porous substrate is immersed in the composition for forming a cationic or anionic polymer electrolyte coating layer to form the cationic or anionic polymer electrolyte coating layer step
Wherein the separator is made of a metal. 16. The method of claim 15,
A step of immersing the porous substrate in the composition for forming a cationic polymer electrolyte coating layer, a step of immersing the composition in the composition for forming an anionic polyelectrolyte coating layer, and a combination thereof are repeated a plurality of times By weight based on the total weight of the separator. Anode and cathode, and
And a separator interposed between the positive electrode and the negative electrode,
Wherein the separator is the separator according to claim 1. 18. The method of claim 17,
Wherein the electrochemical cell is a lithium secondary battery. 19. The method of claim 18,
Wherein the negative electrode comprises lithium metal.

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