This application claims the benefit of priority based on the date of 18 Korea Patent Application No. 2018-0002493 January 2018, and all information disclosed in the literature of the Korea patent application are included as part of the specification.
[2]
The present invention for the electrochemical device, a secondary battery separator and apply it, and more particularly, when using a large amount of dispersing resin for dispersing the inorganic material, dispersed resin amount and the dispersant used both in order to rule out the resistance increase after the membrane coating is generated a is for a secondary battery, a separator and an electrochemical device is applied to reduce them.
BACKGROUND
[3]
A secondary battery that can be charged and discharged, the electricity that is being proposed as a method for solving such as air pollution, such as conventional gasoline vehicles and diesel vehicles using fossil fuel vehicles (EV), hybrid electric vehicles (HEV), plug-in , including hybrid electric vehicles (Plug-in HEV) it has received attention as a power source for devices which require high-output, large-capacity.
[4]
Secondary batteries, depending on the shape of it be classified as a cylindrical battery cell, a prismatic battery cell, a pouch-type battery cell or the like. On the other hand, the battery case, the positive electrode / separator / a power generation device capable of charge and discharge made of a layered structure of the cathode there is a built-in electrode assembly, the electrode active material are wound by interposing a separator between the positive electrode and the negative electrode of a long sheet-shaped coating jelly-roll type structure and are classified a number of positive and negative electrodes of a predetermined size in a stacked structure stacked in sequence in a membrane interposed state.
[5]
In order to ensure safety and improvement of the lithium secondary battery is a physical, electrochemical stability of the membrane is particularly important among various arrangements included in the lithium secondary battery. A lithium secondary battery separator that is commonly used is to use a polyolefin-based micro-porous film made of a thin-film polyethylene or polypropylene materials. The main material because of its high thermal stability for forming the case of such a polyolefin-based separator having a separator of a microporous membrane from damage or deformation due to a temperature rise resulting from the abnormal movement of the cells may take place easily. Then, the short circuit between the electrodes with the microporous membrane damage or deformation can occur and there is a risk of overheating of the battery, ignition and explosion. Of ignition or explosion of the battery case it is reported in recent years, and a number, and this case is that the hayeotgi of safety that need to be essential to the accompanying with the increase of the battery capacity is insufficient.
[6]
This, as one of methods for improving the safety of the battery is also used for a method for improving the safety of the battery through the thermal stability improvement of the separation membrane to form a coating layer containing an inorganic material over the polyolefin-based film.
[7]
However, a situation that after the separator coating in accordance with the increase in the content of the dispersion resin to be added in order to improve the dispersibility of the inorganic material to be added in order to form such a membrane technology can be used a small amount of resistance increase and expensive dispersants are required.
[8]
Prior art in the Korea Patent Laid-Open Publication No. 2009-0118089 call the polyvinyl alcohol and the hydrophobic monomer in the water reaction medium, and using an initiator to prepare a colloidal polymer latex obtained by polymerization reaction in an aqueous solution, the polymer colloid latex cast coating coating a plastic base band process, it discloses a lithium ion battery, the microporous polymer membrane, characterized in that is produced by separation and dried. However, a separator slurry configuration having a limited content of a dispersion resin and dispersant which limits the weight average molecular weight is not disclosed.
[9]
Korea Patent Laid-Open Publication No. 2017-0024574 call the porous polymeric substrate; And a porous coating layer formed on at least one surface of said porous polymeric substrate; The composite membrane, wherein the composite membrane wherein the porous coating layer, and an electrode layer formed on both surfaces or at least one surface of its outermost surface include inorganic particles and a binder resin, the inorganic particles containing the surface by the binder resin all or is partly covered with it is that the integrated particles by points a binder and / or surface binding between the inorganic particles are formed in a layer, the porous coating layer due to the interstitial volume (interstitial volume) in between the inorganic particles It will have a porous structure, wherein the electrode is an adhesive layer comprising a particulate polymer having an adhesive property and the particulate polymer, but discloses a composite separator for an electrochemical device to a glass transition temperature of -110 to 0 ℃ ℃ , dispersion resin and a small amount of in has a characteristic to improve the dispersibility and the dispersing agent obtain The castle is not disclosed.
[10]
Korea Patent Laid-Open Publication No. 2017-0053010 call the porous polymeric substrate; And a porous coating layer formed on at least one surface of said porous polymeric substrate; The composite membrane, wherein the composite membrane wherein the porous coating layer, and an electrode layer formed on both surfaces or at least one surface of its outermost surface include inorganic particles and a binder resin, the inorganic particles containing the surface by the binder resin all or is partly covered with it is that the integrated particles by points a binder and / or surface binding between the inorganic particles are formed in a layer, the porous coating layer due to the interstitial volume (interstitial volume) in between the inorganic particles will have a porous structure, wherein the electrode is an adhesive layer comprising a particulate polymer having an adhesive property and the particulate polymer is a polymer disclosed the composite separator for an electrochemical device to a glass transition temperature of -110 to 0 ℃ ℃, dispersion resin and dispersant configured as input a bit having the features in the dispersibility improvement is more Not set forth.
[11]
Korea Patent Application No. 1750325 in the porous substrate having pores; And the heat-expandable microcapsule comprising a ethylene-based polymer shell that is supported on at least one side of the porous substrate, and this liquid hydrocarbon; And comprises a mixture of a binder polymer, wherein the ethylene polymer shell whose in softening temperature than the high temperature, but discloses a porous separator, characterized in that the volume expansion, only the content of the dispersion resin and dispersant which is limited to the weight average molecular weight membrane slurry having the configuration is not disclosed.
[12]
Therefore, without using a dispersing resin in an amount in excess minutes can enhance the acid while electrochemical mineral slurry applied secondary battery separator having the technical features in the dispersion resin and dispersant which can be excluded in the resistance after the coating on the porous membrane, and it a situation there is a need for a high-technology device.
[13]
(Prior art document)
[14]
[Patent Document 1] Korea Patent Laid-Open Publication No. 2009-0118089 No.
[15]
[Patent Document 2] Korea Patent Laid-Open Publication No. 2017-0024574 No.
[16]
[Patent Document 3] Korea Patent Laid-Open Publication No. 2017-0053010 No.
[17]
[Patent Document 4] Korea Patent Publication No. 1750325 No.
Detailed Description of the Invention
SUMMARY
[18]
The present invention aims to provide an electrochemical device, a secondary battery separator and apply it, also can improve the dispersibility of the membrane by introducing a small amount in order to solve the technical problem, which has been requested from the prior art problems, and as described above do.
[19]
Further, the present invention is to provide a secondary battery, a separator and an electrochemical device applying it to eliminate the resistance increase occurring after coating the mineral slurry to the membrane for the purpose.
[20]
In addition, even if a small amount of expensive dispersants and an object thereof is to provide a secondary battery, a separator and an electrochemical device applying them to obtain a dispersion effect equal to or more.
Problem solving means
[21]
Secondary battery separator and an electrochemical device, applying the same according to the present invention for achieving this purpose,
[22]
The porous polymeric membrane substrate having a plurality of pores; In the secondary battery, a separator, a dispersion resin having a weight average molecular weight in the inorganic material layer is more than 500,000, or a viscosity of 550cps, including; inorganic layer comprising an inorganic substance and a binder disposed on at least one surface of the separator base material; And a dispersant; may be formed of a secondary battery separator comprising a.
[23]
Further, the resin dispersion may be made of a polymer resin comprising a cyan.
[24]
In addition, the dispersant may comprise a fatty acid.
[25]
Further, the total content of the polymer resin and the fatty acid may be from 0.5 to 10%, based on the weight of the inorganic material.
[26]
In addition, the amount of the fatty acid can be 1 to 30% by weight of the polymer resin content.
[27]
In addition, the composition for forming an inorganic material layer with respect to 100 parts by weight of inorganic material, wherein the dispersed resin is less than 10 parts by weight, the dispersing agent may include less than 3 parts by weight.
[28]
In addition, the dispersant may be minutes with 8 to 22 carbon atoms, branched or unbranched saturated or unsaturated fatty acids.
[29]
In addition, the separator base material is polyethylene (polyethylene), PP (polypropylene), polyethylene terephthalate (polyethyleneterephthalate), polybutylene terephthalate (polybutyleneterephthalate), polyester (polyester), polyacetal (polyacetal), polyamide (polyamide) , polycarbonate (polycarbonate), polyimide (polyimide), polyether ether ketone (polyetheretherketone), poly aryl ether ketone (polyaryletherketone), polyetherimide (polyetherimide), polyamide-imide (polyamideimide), polybenzimidazole (polybenzimidazole) , polyether sulfone (polyethersulfone), polyphenylene oxide (polyphenyleneoxide), cyclic olefin and a polymer (cyclic olefin copolymer), polyphenylene sulfide (polyphenylenesulfide) and polyethylene naphthalene one selected from the group consisting of (polyethylenenaphthalene) a polymer or of these, formed of a mixture of two or more Polymer film or may be those of a multi-film, a woven fabric or nonwoven fabric.
[30]
Further, the inorganic particles can be selected from inorganic particles, and mixtures thereof with inorganic particles, the lithium ion conductivity than a dielectric constant of 5.
[31]
It may be an electrochemical device comprising a separation membrane comprising the technical features interposed between an anode, a cathode, and the anode and the cathode.
[32]
In the inorganic layer to form a binder solution by dissolving with a solvent, a dispersing agent dispersed in the resin and fatty acids; Phase in which the inorganic particles forming the dispersed slurry by the addition of inorganic particles to the binder solution and stirred; And the step of applying to at least one surface of a porous substrate having pores the slurry; And the porous drying the slurry coated on at least one surface of the substrate; wherein the the As the drying step is conducted, in sequence in the thickness direction from the porous substrate is a porous layer and binder layer are formed, wherein the dispersion resin has a weight-average a polymer resin to a molecular weight comprising a cyan less than 500,000 or more, or viscosity of 550cps, in at least one surface of the inorganic material 100 is less than 10 parts by weight per part by weight of the dispersant is less than 3 parts by weight of the porous coating layer has the porous base regions, or it may be made by the process of the separation membrane in an area of ​​the pores of the at least one surface and the porous base material of the porous substrate.
[33]
Structure and its manufacturing method of these electrochemical devices are so well known in the art, in the present specification a detailed description thereof will be omitted.
Brief Description of the Drawings
[34]
1 is a conceptual view showing a separation membrane comprising a porous substrate, the porous coating layer and a binder layer made according to one embodiment of the present invention.
[35]
Figure 2 is a process flow diagram of a method of manufacturing a separator according to an embodiment of the present invention.
[36]
3 is an improved coating properties result when the separation membrane according to an embodiment of the present invention.
[37]
Figure 4 is a slurry improved dispersibility results in accordance with an embodiment of the present invention.
Mode for the Invention
[38]
Reference to the accompanying drawings self having ordinary skill in the art will be described in detail an embodiment that can easily practice the invention. However, if it is determined that in the following description of the detail of the operation principle of a preferred embodiment of the present invention is a detailed description of known functions or constructions may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.
[39]
1 is a conceptual diagram of a slurry for forming a schematic view showing the section and the coating layer of a membrane comprising a porous substrate, the porous coating layer and a binder layer made according to one embodiment of the present invention.
[40]
Membrane according to one aspect of the present invention is a porous substrate having a plurality of pores; Located on at least one surface and a part or all of the plurality of inorganic particles and the surface of the inorganic particles, is formed in at least one area of ​​the pores of the porous base material of the porous substrate with a binder for connecting and fixing between the inorganic particles porous coating layer comprising; And comprises a binder layer formed on the porous coating layer. Here, the binder layer of the present invention is porous because it improves the ionic conductivity of the membrane, in particular has a superior adhesion characteristics to the electrodes.
[41]
In addition, the binder layer is an adhesive layer functions as an electrode for facilitating cell adhesion of the porous coating layer and the electrode upon assembly of the electrode, such as after assembly.
[42]
If the porous substrate is generally a porous substrate used in the electrochemical device, it is possible to use both. But it is not limited to polyethylene in the porous base material (polyethylene), PP (polypropylene), polyethylene terephthalate (polyethyleneterephthalate), polybutylene terephthalate (polybutyleneterephthalate), polyester (polyester), polyacetal (polyacetal), polyamide (polyamide ), polycarbonate (polycarbonate), polyimide (polyimide), polyether ether ketone (polyetheretherketone), poly aryl ether ketone (polyaryletherketone), polyetherimide (polyetherimide), polyamide-imide (polyamideimide), polybenzimidazole (polybenzimidazole ), polyether sulfone (polyethersulfone), polyphenylene oxide (polyphenyleneoxide), cyclic olefin and a polymer (cyclic olefin copolymer), polyphenylene sulfide (any one of a polymer selected from the group consisting of polyphenylenesulfide) and polyethylene naphthalene (polyethylenenaphthalene) or a mixture of two or more of these Or the generated polymer may be those of a multi-film, a woven or non-woven fabric, but are not limited to.
[43]
The thickness of the porous substrate is not particularly limited, about 5 and may be about 50㎛, pore size and pore present in the porous substrate also is not particularly limited, about 0.01 to about 50㎛, and from about 10 to about 95, respectively % can be.
[44]
The dispersion resin of the binder role is cyano (Cyano) system, and it is apparent that a choice of a polymer comprising a cyano group.
[45]
However, and in the present invention and a cyano resin for use in the resin molecular weight distribution cyano applying no resin to improve the dispersibility with only a small amount of dispersion resin added increases Chengdu adhesive and characters.
[46]
The weight average molecular weight (Mw) of the cyano-resin may be at least 500,000.
[47]
The viscosity of the cyano-resin may be more than 550cps.
[48]
The viscosity was used as a Brook field viscometer (LV model), the cyano resin in the DMF solution from the spindle 52, 12 rpm condition was measured after dissolution to 20 wt%.
[49]
Further, a dispersion resin is added to the binder may be mixed to further enhance the binding property between the inorganic particles in addition to the above-described dispersed resin, an increase in the durability of the porous coating and the like. Such additional binders include, but are not limited to, polyarylate (polyarylate), polyvinylidene fluoride (polyvinylidene fluoride, PVdF), polyvinylidene fluoride-hexafluoropropylene (polyvinylidene fluoride-ohexafluoropropylene), polyvinylidene fluoride - trichlorethylene (polyvinylidene fluoride-co-trichloroethylene) polymethyl methacrylate (polymethylmethacrylate), polyacrylonitrile (polyacrylonitrile), polyvinylpyrrolidone (polyvinylpyrrolidone), polyvinyl acetate (polyvinylacetate), ethylene-co-vinyl acetate (polyethyleneco-vinyl acetate), polyethylene oxide (polyethylene oxide), cellulose acetate (cellulose acetate), cellulose acetate butyrate (cellulose acetate butyrate), cellulose acetate propionate (cellulose acetate propionate), cyanoethyl pullulan (cyanoethylpullulan) , cyanoethyl polyvinyl alcohol (cyanoethy lpolyvinylalcohol), cyanoethyl cellulose (cyanoethylcellulose), cyanoethyl sucrose (cyanoethylsucrose), pullulan (pullulan), carboxyl methyl cellulose (carboxyl methyl cellulose),
[50]
Optionally, in accordance with one embodiment of the invention, the porous coating layer may further comprise a dispersing agent.
[51]
In addition, the dispersant may comprise a fatty acid.
[52]
Further, the total content of the polymer resin and the fatty acid may be from 0.5 to 10%, based on the weight of the inorganic material.
[53]
Preferably the total content of the polymer resin and the fatty acid can be 1 to 8% by weight. Outside the above range may be a resistance decreases after a separator coating.
[54]
In addition, the amount of the fatty acid can be 1 to 30% by weight of the polymer resin content.
[55]
Preferably the amount of the fatty acid may be any of 1 to 20% by weight, more preferably from 1 to 10% by weight. Outside the above range, the heat stability may decrease after coating.
[56]
In addition, the composition for forming an inorganic material layer with respect to 100 parts by weight of inorganic material, wherein the dispersed resin is less than 10 parts by weight, the dispersing agent may include less than 3 parts by weight.
[57]
The content ratio of the dispersing agent may be from 1 to 30 according to the following formula.
[58]
The content ratio of (a dispersing agent content (g) / resin dispersion amount (g)) * 100
[59]
In addition, the dispersant may be minutes with 8 to 22 carbon atoms, branched or unbranched saturated or unsaturated fatty acids.
[60]
It is also possible to use mixtures of the fatty acids.
[61]
Similarly, it is also possible to use mixtures of carboxylic acids, such as acetic acid or propionic acid with the above-mentioned fatty acids with 2 to 6 carbon atoms.
[62]
Preferred are each of 10-18 saturated or unsaturated fatty acids having carbon atoms, for example acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, pelargonic, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic, behenic, lignoceric Serre mountains, portrait acid, alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid, gamma-linolenic acid, di-homo - it may be linolenic acid, arachidonic acid, waves sounded acid, oleic acid, El fluoride acid, Eiko sensan, any one or two or more of the fatty acids erucic acid, acid in Nerja - gamma.
[63]
The dispersant may be a mixture of one or more selected from the group consisting of acrylic copolymers. This dispersant exhibits a function as an excellent dispersant for improving the dispersibility of the inorganic material. Further, the dispersing agent has a function as a binder having excellent adhesion with a function as the dispersing agent.
[64]
The dispersant may increase the dispersion of the inorganic hayeoseo interacting with the inorganic material having a surface, by having such a polar group containing polar groups. Further, the dispersant is easy to control physical properties thereof, and can contribute to the stability of the separator and an electrochemical device using the separator including the same will be possible to balance improvement of the dispersibility and adhesion.
[65]
Inorganic particles, just electrochemically stable is not particularly limited. In other words, inorganic particles that can be used in the present invention include electrical operating voltage range of the chemical elements (e.g., Li / Li applied + so long as the oxidation and / or reduction reactions do not occur in the standard 0 to about 5V) is not particularly limited. In particular, in the case of using the inorganic particles in the ion conductivity can be improved performance, increasing the ion conductivity in the electrochemical device.
[66]
In addition, the contribution in the case of using the inorganic particles as the high dielectric constant inorganic particles, the electrolyte salt liquid electrolyte, such as increased dissociation of the lithium salt can enhance the ionic conductivity of the electrolyte.
[67]
Because of the aforementioned reasons, the inorganic particles may include inorganic particles or a mixture thereof having at least a dielectric constant of about 5, such as about 10 or more high dielectric constant inorganic particles, the lithium ion conductivity. Non-limiting examples of a dielectric constant of about 5 or more inorganic particles is BaTiO 3 , 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 , TiO 2 has, SiC, or a mixture thereof.
[68]
BaTiO 3 , 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 ) and the piezoelectric to the potential difference between the both sides caused by electric charge is generated when such inorganic particles not only exhibit a dielectric constant of about 100 or more high dielectric constant characteristics, is applied by tension or compression to a predetermined pressure ( by having the piezoelectricity), to prevent internal short circuit of both electrodes due to external impact can be reduced to improve the safety of an electrochemical device. Moreover, when mixing the inorganic particles having a high dielectric constant inorganic particles with lithium ion conductivity thereof increases above effect it may be doubled.
[69]
Mineral grain size, but is limited and can be suitable for the coating layer formed and the porosity of uniform thickness, with about 0.01 to about 10㎛, or from about 0.05 to about 1.0㎛ possible. If the size of the inorganic particles satisfy the above range, the dispersibility is improved when easy to adjust the physical properties of the separation membrane, and the thickness of the porous coating layer is increased in the mechanical properties due to the excessively large pore size may be degraded, or the battery charge and discharge there is a problem arise internal short circuit can be prevented.
[70]
The composition ratio of a binder containing inorganic particles and dispersion resin in the porous coating layer, for example about 50:50 to about 99: 1, or from about 60:40 to about 95: may be 5 days. The thickness of the porous coating layer consisting of inorganic particles and binder Although there is no particular limitation, may be from about 0.01 to about 20㎛ range. In addition, pore size and porosity but is also no particular limitation, the pore size is about 0.01 to about 5㎛ range, the porosity may be from about 5 to about 75% by weight.
[71]
May further comprise other additives commonly used in the art in addition to the inorganic particles and the polymer described above as components of the porous coating layer is apparent.
[72]
According to a further aspect of the invention, an anode, a cathode, and the anode and the the electrochemical device, such as a lithium secondary battery described above it is interposed a separator between the negative electrode is provided.
[73]
Figure 2 is a schematic flow diagram of a method of manufacturing a separation membrane according to another embodiment of the invention. Referring to FIG. 2, according to another aspect of the invention, a method for manufacturing a separation membrane comprising a forming step (S1), step form of slurry (S2) and the forming of a porous coating layer (S3) of the binder solution is provided.
[74]
And a binder and the solubility parameter to be used are similar to the solvent, it is preferred that the low boiling point. This is because the can may be made mixing a uniform, easily removed after solvent. In particular, the solvent is a polar solvent having a boiling point of less than 100 ℃ is preferred. However, in the case of a non-polar solvent it is undesired for, since there is a fear of the dispersion decreases.
[75]
Non-limiting examples of solvents include acetone (acetone), in tetrahydrofuran (tetrahydrofuran), methylene chloride (methylene chloride), chloroform, (chloroform), dimethylformamide (dimethylformamide), N- methyl-2-pyrrolidone (Nmethyl- 2-pyrrolidone, may be NMP), cyclohexane (cyclohexane), 1 either individually or in combination of two or more thereof selected from the group consisting of such as water.
[76]
Solvents include solids and 100 parts by weight of the total amount of solvent, i.e., inorganic, solid mixture of binder and a dispersing agent and two types of solvents (e. G., Polar solvent) of about 50 to about 90 parts by weight in a total amount of 100 parts by weight based on parts of. When the solvent is deteriorated, it had a solids and due to the increased viscosity of less than 50 parts by weight of a total amount of 100 parts by weight based on the solvent, coatability and the great difficulty occurs in the formation of the binder layer, and there is the difficulty of delamination, and, conversely, more than 90 parts by weight, productivity It can result in an increase in the degradation and production cost.
[77]
In step S2, the addition of inorganic particles to the binder solution formed in the step S1 to form the said inorganic particles dispersed slurry by stirring.
[78]
After the addition of inorganic particles to the binder solution, it may be subjected to crushing of the inorganic particles. The crushing time is suitably about 1 to about 20 hours, and the particle size of the crushed inorganic particles may be from about 0.01 to about 3㎛. Fracturing methods may be used conventional methods, in particular for a milling method such as ball mill (ball mill) method.
[79]
How the inorganic particles are coated with a dispersion slurry on the porous substrate may be a known conventional coating methods in the art, for example dip (Dip) coating, die (Die) coating, roll (roll) coating, comma (comma) or coating may be used in a variety of ways such as a mixture of these methods. In addition, the porous coating layer may be selectively formed only on both sides or one side of the porous substrate.
[80]
Drying may be used for any method known in the art, using an oven or a heated chamber in consideration of the vapor pressure of the solvent used the temperature range is possible by a batch-wise or continuously. The drying is to substantially remove the solvent present in the slurry, which can be carried out preferably as fast as possible in consideration of the productivity, for example, less than one minute, preferably for less than 30 seconds.
[81]
According to the invention in the drawings will be described as in the detailed embodiment.
[82]
(Example 1)
[83]
3, the comparison with Example 1, for preparing a slurry by adding a dispersing agent 5 ~ 10 wt% to the dispersion resin having cyano groups only weight average molecular weight of 30 to 40 to then was coated on the membrane in Example 1, a weight average after the dispersion resin having a cyano group only molecular weight 50 to 60 for preparing a slurry, a dispersant cheomgahyeong 5 ~ 10 wt% was coated on a separator.
[84]
Membrane interface-coating adhesive strength evaluation after attaching the after adhering the double-faced tape to the glass plate length to adhere the membrane of the 60mm and width 15mm, and the adhesive tape, by using a UTM (Universal Testing Machine) equipment with a membrane attached to the adhesive tape the peeling speed 300mm / min, (separation direction?) was measured while pulling 180 degrees.
[85]
Membrane surface - in the case of Example 1 when compared to 80 (gf / 15mm) of Comparative Example 1, comparing the coating adhesion, as measured in 110 (gf / 15mm) was found improved adhesion.
[86]
Also it confirmed the improved value of 15% / 10% in Comparative Example 1 in a 40% / 35% that of Comparative Example 1 was measured in the heat shrinkage (MD / TD) to 150 ℃, 1 time conditions.
[87]
In addition, a weight average molecular weight of 500,000 or more, or a viscosity of use of cyano resin than 550cps, when using a ratio range of dispersant 30% or more membrane interface - decreases in coating adhesion 20 (gf / 15mm), the heat shrinkage modulus 48% / It was found to increase by 45%.
[88]
(Example 2)
[89]
4, the Comparative Example 2 having a weight average molecular weight was coated on a separator and then to prepare a slurry by using a number, but dispersion having a cyano group only 50 to 60, Example 2 to a weight average molecular weight cyano only 50-60 after preparing a slurry, a dispersant cheomgahyeong 5 ~ 10 wt% to the dispersion resin having a group was coated on a separator.
[90]
Was to determine the optimal mixing ratio of the dispersion resin and the dispersing agent, it was confirmed that the dispersion resin and the dispersing agent is the slurry improves the bun be made acidic by the mixing ratio of the appropriate conditions.
[91]
Particle size (D50) is to in the particle size distribution curve of the particles, means the particle diameter corresponding to 50% of the number of accumulation, the average particle diameter of the particles is Particle Size Analyzer was measured through the (product name: Malvern: MASTERSIZER 3000, manufacturer).
[92]
Particle settling velocity Dispersion Analyzer (product name: Lumisizer, Manufacturer: LUM) to measure the sedimentation rate with time in the state of applying a centrifugal force at a rotational speed of 1000rpm by using the.
[93]
In Comparative Example 2 In the case of the particle size (D50) (μm), to check the difference in particle size can be judged dispersibility compared to 3 of example 2 to 10 or more values, precipitation rate (μm / s), in Comparative example 2, it was confirmed that minute is very less compared to the acid to at least 100, example 9.
[94]
Those of ordinary skill in the art that the present invention it will be possible to perform a variety of applications and modifications within the scope of the invention as disclosed in the accompanying claims.
Industrial Applicability
[95]
As described above, the electrochemical device, a separator and a secondary battery applying the same according to the present invention, there is an effect that it is possible to eliminate the resistance increase occurring after the porous separator coating by reducing the content of the dispersing resin.
[96]
In addition, there is an effect that improves the physical properties and dispersibility by mixing the resin dispersion of the specific weight-average molecular weight.
[97]
In addition, there is to eliminate the use of expensive dispersants effects that can reduce the cost of the process.
[98]
In addition, there is an effect that can solve problems, such as when using the commercially available dispersing agent, lowering interfacial adhesion and high-temperature heat shrinkage that may occur after the membrane coating.

WE Claims

[Claim 1]
The porous polymeric membrane substrate having a plurality of pores; Inorganic layer comprising an inorganic substance and a binder disposed on at least one surface of the separator base material; In the secondary battery, a separator, a dispersion resin having in the inorganic material layer having a weight average molecular weight is more than 500,000, or 550cps viscosity, including; And a dispersant; secondary battery separator comprising a.
[Claim 2]
The method of claim 1 wherein the polymer resin of a secondary battery separator of the dispersion resin comprising a cyan.
[Claim 3]
The method of claim 2, wherein the dispersing agent is a fatty acid of a secondary battery separator.
[Claim 4]
According to claim 3, wherein the polymer resin and the total content of said fatty acid is a secondary battery separator of 0.5 to 10% by weight of the inorganic material to prepare.
[Claim 5]
The method of claim 3 wherein the amount of the fatty acid is a secondary battery separator 1 to 30% by weight of the polymer resin content.
[Claim 6]
The method of claim 1, wherein the secondary battery separator of the composition for forming an inorganic material layer with respect to the inorganic material 100 parts by weight of the dispersed resin is less than 10 parts by weight, the dispersing agent comprises less than 3 parts by weight.
[Claim 7]
Claim 6, wherein the dispersing agent is from 8 to 22 minutes, with a carbon atom of a branched or unbranched saturated or unsaturated fatty acids, a secondary battery separator.
[Claim 8]
The method of claim 1, wherein the membrane substrate is a polyethylene (polyethylene), PP (polypropylene), polyethylene terephthalate (polyethyleneterephthalate), polybutylene terephthalate (polybutyleneterephthalate), polyester (polyester), polyacetal (polyacetal), poly amides (polyamide), polycarbonate (polycarbonate), polyimide (polyimide), polyether ether ketone (polyetheretherketone), poly aryl ether ketone (polyaryletherketone), polyetherimide (polyetherimide), polyamide-imide (polyamideimide), Paul Revenge microporous sol (polybenzimidazole), polyether sulfone (polyethersulfone), polyphenylene oxide (polyphenyleneoxide), which is selected from a cyclic olefin and the group consisting of a polymer (cyclic olefin copolymer), polyphenylene sulfide (polyphenylenesulfide) and polyethylene naphthalene (polyethylenenaphthalene) a polymer or a mixture of two or more of these Polymer film or a multi-film, a woven or non-woven fabric formed of a secondary battery separator.
[Claim 9]
The method of claim 1, wherein the secondary battery separator in which the inorganic particles have a dielectric constant is selected from the group consisting of a mixture of inorganic particles and those having 5 or more inorganic particles, the lithium ion conductivity.
[Claim 10]
An anode, a cathode, and an electrochemical device comprising the positive electrode and the separator of any one of the claims 1 to 9 interposed between the negative electrode.
[Claim 11]
In the inorganic layer to form a binder solution by dissolving with a solvent, a dispersing agent dispersed in the resin and fatty acids; Phase in which the inorganic particles forming the dispersed slurry by the addition of inorganic particles to the binder solution and stirred; And the step of applying to at least one surface of a porous substrate having pores the slurry; And the porous drying the slurry coated on at least one surface of the substrate; wherein the the As the drying step is conducted, in sequence in the thickness direction from the porous substrate is a porous layer and binder layer are formed, wherein the dispersion resin has a weight-average a polymer resin to a molecular weight comprising a cyan less than 500,000 or more, or viscosity of 550cps, in at least one surface of the inorganic material 100 is less than 10 parts by weight per part by weight of the dispersant is less than 3 parts by weight of the porous coating layer has the porous base region, or a method of producing a separation membrane in an area of ​​the pores of the at least one surface and the porous base material of the porous substrate.