Novel coating device and coating method of separator electrochemical device using the same

Abstract

The present invention relates to a novel apparatus for coating a separator for an electrochemical device, and a coating method using the same. Specifically, according to one aspect of the present invention, there is an advantage of efficiently pattern-coating a binder on the surface of a separator. In addition, by reversibly modifying the surface of a coating bar for pattern coating, there is an advantage of providing a coating method that facilitates easy pattern modification.

Description

Technology Field

[0001] The present invention relates to a novel apparatus for coating a separator for an electrochemical device, a method for coating a separator using the same, and a separator coated using the same. Background Technology

[0002] Lithium-ion batteries are manufactured through a process in which an electrode assembly, comprising a positive electrode, a separator, and a negative electrode as a single unit, is inserted into a battery case, and then an electrolyte is injected and sealed. At this stage, the separator not only performs the function of blocking physical contact between the positive and negative electrodes, but research is also continuously being conducted to modify the separator to ensure the safety of lithium-ion batteries, such as flame resistance and fire retardancy.

[0003] Primarily, there is a challenge to improve the adhesion between the separator and the anode and cathode to address the short-circuit problem between the anode and cathode caused by the detachment of the separator adjacent to the anode and cathode during battery operation. To this end, a technology has been developed to form an adhesive layer on the surface of the separator using an adhesive binder. However, when the binder is applied across the entire surface of the separator, there is a problem of increased interfacial resistance between the separator and the electrodes. Furthermore, when an adhesive layer is formed across the entire surface of the separator, there has been a problem where the slitting portion comes into contact with the adhesive layer when the separator is cut into a desired shape at the end of the manufacturing process, causing contamination of the device and degradation of the separator's quality.

[0004] In addition to the technology for forming an adhesive layer on the surface of a separator, a technology for coating the surface of a separator with inorganic particles to impart flame retardancy is also being developed. However, since the surface of the separator coated with inorganic particles has little to no adhesion, a technology is being developed to provide an adhesive layer on the inorganic particle coating layer to impart additional adhesion. Similarly, if an adhesive layer is provided on the entire surface of the inorganic particle coating layer, not only does the resistance of the separator increase, but there is also a problem in that it is difficult to uniformly form the adhesive layer on the porous coating layer.

[0005] To address these issues, a technology has been devised to form an adhesive layer in a patterned shape on the surface of a separator. However, despite continuous changes in the composition of the coating layer according to various studies, the technology for performing pattern coating on the surface of the separator is lacking, resulting in the inability to achieve an ideal pattern coating.

[0006] Accordingly, the present invention aims to provide a novel coating apparatus and method that can be used for coating a separation membrane. The problem to be solved

[0007] Accordingly, the problem that the present invention aims to solve is to provide a coating apparatus, a coating method, and a separator for an electrochemical device coated using the same, which solves the aforementioned problem.

[0008] Specifically, according to one aspect of the present invention, a novel apparatus for coating an adhesive layer in a pattern shape on the surface of a separator is provided.

[0009] In particular, according to one aspect of the present invention, a pattern-variable coating apparatus and a coating method using the same are provided so as to enable various patterns to be implemented on the surface of a separation membrane.

[0010] Furthermore, according to one aspect of the present invention, a method for manufacturing a separator is provided by providing an adhesive layer in a patterned shape on the surface of the separator, thereby increasing the ease of the slitting process of the separator.

[0011] In addition, we aim to provide a separator for an electrochemical device with improved resistance and adhesion characteristics manufactured using a novel device. means of solving the problem

[0012] In order to solve the above problem,

[0013] According to one aspect of the present invention, a coating apparatus of the following embodiments is provided.

[0014] The coating device according to the first embodiment is,

[0015] Cylindrical coating bar,

[0016] A surface treatment section provided spaced apart from the above coating bar, and

[0017] It includes a pattern masking part provided between the coating bar and the surface treatment part, and

[0018] The above surface treatment unit includes at least one of a plasma irradiator and a corona irradiator, and

[0019] The pattern masking part above has a transmission region and a non-transmission region of the plasma or corona.

[0020] According to the second embodiment, in the first embodiment,

[0021] The above pattern masking part may be a metal plate or a polymer film material.

[0022] According to the third embodiment, in the first embodiment or the second embodiment,

[0023] The above pattern masking part may have a pattern in which the transparent area and the non-transparent area alternate and repeat.

[0024] According to the fourth embodiment, in any one of the first to third embodiments,

[0025] A coating solution tank is provided to provide a coating solution to at least a portion of the surface of a surface-treated coating bar, and the coating solution may include a binder.

[0026] According to the fifth embodiment, in any one of the first to fourth embodiments,

[0027] The above coating solution may further include inorganic particles.

[0028] According to the 6th embodiment, in any one of the 1st to 5th embodiments,

[0029] It may further include a transfer unit that provides a coating substrate to a coating bar on which a coating liquid is applied to at least a portion of the surface.

[0030] According to the seventh embodiment, in any one of the first to sixth embodiments,

[0031] The above coating substrate may be a separator for an electrochemical device.

[0033] According to another aspect of the present invention, a method for coating a separation membrane of the following embodiments is provided.

[0034] The coating method of the separation membrane according to the 8th embodiment is,

[0035] (S1) A step of treating at least a portion of the surface of a cylindrical coating bar, and

[0036] (S2) A step of coating a coating solution containing a binder on at least one surface of a coating substrate using the surface-treated coating bar, and

[0037] The above step (S1) includes plasma irradiation or corona irradiation on the surface of the coating bar while at least a portion of the surface of the coating bar is pattern masked.

[0038] According to the ninth embodiment, in the eighth embodiment,

[0039] In the above step (S1), the surface of the coating bar before surface treatment is hydrophobic, and the surface of the surface-treated coating bar may be modified to be hydrophilic.

[0040] According to the 10th embodiment, in the 8th or 9th embodiment,

[0041] The above coating solution may be a dispersion in which the binder is dispersed in an aqueous solvent.

[0042] According to the 11th embodiment, in any one of the 8th to 10th embodiments,

[0043] The above coating solution may further include inorganic particles.

[0044] According to the 12th embodiment, in any one of the 8th to 11th embodiments,

[0045] The above coating substrate may include a porous polymer substrate.

[0046] According to the 13th embodiment, in any one of the 8th to 12th embodiments,

[0047] The above coating substrate may include a porous polymer substrate and a porous coating layer provided on at least one surface of the porous polymer substrate and comprising inorganic particles.

[0049] According to another aspect of the present invention, a separator for an electrochemical device of the following embodiments is provided.

[0050] The separator according to the 14th embodiment is,

[0051] A separator for an electrochemical device having at least one surface coated according to any one of the eighth to thirteenth embodiments,

[0052] The surface of the above-mentioned coated separator is formed to have the binder pattern coated thereon. Effects of the invention

[0053] A coating device according to one aspect of the present invention can increase the efficiency of a method for pattern coating an adhesive layer on the surface of a separator.

[0054] In addition, the coating device has the advantage of improving the ease of cutting the separator during a subsequent process of the separator manufacturing process or the manufacturing process of an electrochemical device by coating an adhesive layer in a patterned shape on the surface of the separator.

[0055] Furthermore, the coating device has the advantage of being able to stably pattern coat a hydrophilic coating solution due to the hydrophilic modification of the surface of the coating bar for pattern coating.

[0056] In addition, using the above coating device has the advantage of enabling the realization of various coating patterns by reversibly modifying the surface of the coating bar for pattern coating. Brief explanation of the drawing

[0057] FIG. 1 is a schematic diagram of a coating device (1) according to one embodiment of the present invention. FIG. 2 is a schematic diagram of a pattern masking unit (30) according to one embodiment of the present invention. FIG. 3 is a schematic diagram of the operation of a coating device according to one embodiment of the present invention. FIG. 4 is a schematic diagram showing a surface change of a coating bar that has been surface-modified non-permanently according to one embodiment of the present invention. Specific details for implementing the invention

[0058] The present invention will be described in detail below.

[0059] In this specification, when a part is described as "comprising" a certain component, it means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0060] Specific terms used in the following detailed description of the invention are for convenience only and are not intended to limit the invention. Additionally, words indicating direction, such as up, down, left, right, front, back, inside, and outside, indicate directions in the referenced drawings or directions toward or away from the geometric center of the respective designated device, system, and its components.

[0061] Coating device and coating method

[0062] A coating device according to one aspect of the present invention is,

[0063] Cylindrical coating bar,

[0064] A surface treatment section provided spaced apart from the above coating bar, and

[0065] It includes a pattern masking part provided between the coating bar and the surface treatment part, and

[0066] The above surface treatment unit includes at least one of a plasma irradiator and a corona irradiator, and

[0067] The pattern masking part above has a transmission region and a non-transmission region of the plasma or corona.

[0068] In one embodiment of the present invention, the coating device may be for pattern coating an adhesive layer containing a binder on one surface of a separator, but the use of the coating device is not limited thereto.

[0069] In another embodiment of the present invention, the coating device may be for pattern coating a porous coating layer containing a binder and inorganic particles on one surface of a separator, but as described above, the use of the coating device is not limited thereto.

[0070] In one embodiment of the present invention, the separator serving as the coating substrate may be, for example, of the following first or second type. However, the present invention is not limited thereto.

[0071] The above-described first type of separator consists solely of a porous substrate. That is, as a separator used in conventional electrochemical devices, specifically secondary batteries, the separator may be in the form of a porous film or a porous sheet, serving as an ion-conducting barrier that allows ions to pass through while blocking electrical contact between the positive and negative electrodes. Additionally, the separator may be composed of a nonwoven fabric, a polyolefin-based material, etc.

[0072] According to one embodiment of the present invention, when the coating substrate is a separation membrane of the first type, the coating device can form an adhesive layer containing a binder in a pattern shape on the surface of the porous substrate.

[0073] According to another embodiment of the present invention, when the coating substrate is a separation membrane of the first type, the coating device may form a porous coating layer containing a binder and inorganic particles in a pattern shape on the surface of the porous substrate.

[0074] The second type of separator described above comprises a porous coating layer containing inorganic particles on the porous substrate. The porous coating layer is formed to contain heat-resistant inorganic particles on the porous substrate to improve the heat resistance of the conventional separator. According to one embodiment, the porous coating layer may comprise only the inorganic particles. In this case, the separator having the porous coating layer has the characteristic of having no or insufficient adhesion to the electrode (anode or cathode). Furthermore, according to another embodiment, the porous coating layer may further comprise a coating layer binder that binds the inorganic particles in addition to the inorganic particles. Specifically, when the porous coating layer comprises inorganic particles and a coating layer binder, the inorganic particles may be included in an amount of 80% or more by weight, 85% or more by weight, 90% or more by weight, 95% or more by weight, or 98% or more by weight based on the total weight of the porous coating layer, and in this case as well, it has the characteristic of having insufficient adhesion between the separator and the electrode.

[0075] According to one embodiment of the present invention, when the coating substrate is a separator of the second type, the coating device may form an adhesive layer containing a binder in a pattern shape to provide additional adhesion on the surface of the porous coating layer.

[0076] Specifically, a coating device according to one aspect of the present invention is intended to pattern-coat a coating liquid onto the surface of a coating substrate using a conventional bar coating device.

[0077] In one embodiment of the present invention, the coating bar is not particularly limited in its material, but may, for example, be a coating bar used in a conventional bar coating device. The coating bar may typically be made of stainless steel, but other metallic materials, polymer materials, or mixtures thereof may also be used, and is not limited thereto.

[0078] In order to apply pattern coating using a coating bar made of conventional materials such as stainless steel, a method has been devised in which an embossed or engraved pattern is formed directly on the surface of the coating bar and then used for pattern coating. However, this method is not suitable as a coating method because it is difficult to change the pattern once an embossed or engraved pattern has been formed on the coating bar. Furthermore, since the wettability of the hydrophilic coating solution is poor on the surface of the conventional coating bar, even if an embossed or engraved pattern is formed on the surface, the wettability between the surface of the coating bar and the coating solution remains poor. Consequently, to achieve the desired coating loading amount, the coating process must be repeated multiple times, or problems such as poor coating quality have been encountered.

[0079] According to one aspect of the present invention, the surface of a coating bar is non-permanently modified, and there is an advantage in that a coating device suitable for pattern coating is provided.

[0080] FIG. 1 shows a schematic diagram of a coating device according to one embodiment of the present invention, and FIG. 2 shows a schematic diagram of a pattern masking part used in a coating device according to one embodiment of the present invention.

[0081] Referring to FIGS. 1 and 2, the coating device comprises a cylindrical coating bar (10), a surface treatment unit (20) spaced apart from the coating bar, and a pattern masking unit (30) provided between the coating bar and the surface treatment unit. The surface treatment unit includes at least one of a plasma irradiator and a corona irradiator (not shown). The surface of the cylindrical (10) is modified by plasma or corona emitted from the plasma irradiator or corona irradiator, and in order to modify the surface of the cylindrical (10) into a pattern shape, the pattern masking unit (30) is provided with a transmission area (301) and a non-transmission area (302) of the plasma or corona.

[0082] According to one embodiment of the present invention, the pattern masking part may have a transmission area and a non-transmission area for the plasma or corona, thereby performing the function of modifying the surface of the coating bar only in the area where the plasma or corona passes through the transmission area and reaches the surface of the coating bar.

[0083] At this time, the transparent area and the non-transparent area in the pattern masking part are areas separated from each other, for example, the transparent area and the non-transparent area may have a repeating pattern that intersects, but the present invention is not limited thereto.

[0084] FIG. 3 shows a schematic diagram of the operation of a coating device (1) according to one embodiment of the present invention.

[0085] Referring to FIG. 3, the surface treatment unit (20) irradiates plasma or corona from a plasma irradiator or corona irradiator toward the surface of the coating bar (10). At this time, the emitted plasma or corona passes through the pattern masking unit (30) and modifies the surface of the coating bar. Specifically, only the area reached by the plasma or corona that has passed through the transmission area (301) on the surface of the coating bar is modified, and accordingly, the surface of the coating bar has a pattern modified characteristic according to the pattern of the pattern masking unit (30). As shown in FIG. 3, since it is desirable for the surface modification of the cylindrical coating bar to be performed uniformly along the circumference, it may be desirable for the coating bar to rotate at a constant speed when plasma or corona is emitted from the surface treatment unit.

[0086] According to one embodiment of the present invention, the plasma irradiator and the corona irradiator may be used without particular limitation as long as they are capable of modifying the surface of a coating bar. Specifically, the plasma irradiator and the corona irradiator may be used without limitation as long as they are intended to modify the surface of a coating bar, which generally has a hydrophobic surface, to be hydrophilic.

[0087] In this specification, the surface modification by plasma treatment may be performed by generating plasma by electric discharge after introducing argon or nitrogen gas under vacuum or atmospheric pressure conditions, but the present invention is not limited thereto and conventional plasma treatment methods may be used.

[0088] In this specification, the surface modification by corona treatment may be surface treatment by high-frequency discharge, but the present invention is not limited thereto and a conventional plasma treatment method may be used.

[0089] According to one embodiment of the present invention, the surface treatment unit may preferably include a plasma irradiator when the material constituting the coating bar is a metallic material, a polymer material, or a mixture thereof.

[0090] According to another embodiment of the present invention, the surface treatment unit may preferably include a corona irradiator when the material constituting the coating bar is a polymer material.

[0091] According to one embodiment of the present invention, the surface of the coating bar may be hydrophilized by surface modification by plasma treatment and surface modification by corona treatment. In particular, the surface of the coating bar may be hydrophilized by pattern modification by the pattern masking part.

[0092] In this case, since the surface modification by the plasma treatment and the surface modification by the corona treatment are non-permanent modification methods, the surface of the modified coating bar has the advantage of being able to return to its original properties after a predetermined period of time or through a separate recovery process.

[0093] FIG. 4 illustrates a schematic diagram showing a surface change of a coating bar that has been surface-modified non-permanently according to one embodiment of the present invention. Referring to FIG. 4, the surface-modified coating bar can be restored to a single property over time as the surface pattern disappears.

[0094] According to one embodiment of the present invention, the pattern masking unit is provided to perform the role of blocking the transmission of plasma or corona in a pattern shape so that plasma or corona emitted from the surface treatment unit is transmitted to the coating bar only in some areas and is blocked from reaching the coating bar.

[0095] To this end, the pattern masking part (30) is provided with a plasma or corona transmission area (301) and a non-transmission area (302).

[0096] According to one embodiment of the present invention, a pattern formed by the transparent area and the non-transparent area provided in the pattern masking part may be transferred to the surface of the coating bar. The specific shape of the pattern is not particularly limited in the present invention.

[0097] In one embodiment of the present invention, the pattern may have a repeating pattern in which the transparent area and the non-transparent area each have a square shape and intersect, but the present invention is not limited thereto.

[0098] In one embodiment of the present invention, since the pattern masking portion has a non-transparent region that blocks plasma or corona as described above, it can be used with any material capable of blocking plasma or corona without particular limitation. For example, the pattern masking portion may be composed of a polymer material such as a polymer film, a metal material such as stainless steel, or a mixture thereof.

[0099] In one embodiment of the present invention, when the pattern masking part is a metal material such as stainless steel, the pattern formed on the pattern masking part may be formed through a waterjet cutter or through a metal etching solution, but the method of forming the pattern of the pattern masking part is not limited thereto.

[0100] In another embodiment of the present invention, when the pattern masking part is a polymer material such as a polymer film, the pattern formed on the pattern masking part may be formed through a known cutting method, but the method of forming the pattern of the pattern masking part is not limited thereto.

[0101] According to one embodiment of the present invention, the coating device may further comprise a coating liquid tank for providing a coating liquid to the coating bar after the surface is patterned by the surface treatment unit and the pattern masking unit. In this case, the coating liquid tank may include a binder.

[0102] Specifically, when an adhesive layer containing a binder is formed on the surface of the separator by the coating device, the coating liquid tank can accommodate an adhesive binder.

[0103] In addition, when a porous coating layer containing a binder and inorganic particles is formed on the surface of the separation membrane by the above coating device, the coating liquid tank may further contain inorganic particles in addition to the binder.

[0104] In one embodiment of the present invention, when forming an adhesive layer containing a binder on the surface of a separator using the coating device, the binder contained in the coating liquid tank may be used without particular limitation as long as it is an adhesive binder. For example, the adhesive binder may include an acrylic polymer, a PVDF polymer, or a mixture thereof.

[0105] The above acrylic polymer may include, for example, (meth)acrylic polymers. The above (meth)acrylic polymer is a general term for polymers containing (meth)acrylic acid esters as monomers. The monomers of the above acrylic polymer are, for example, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxymethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, n-oxyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, 1-hydroxy-n-propyl (meth)acrylate, 2-hydroxy-n-propyl (meth)acrylate, 3-hydroxy-n-propyl (meth)acrylate, lauryl (meth)acrylate, tetra Examples may include decyl (meth)acrylate, acrylamide, (meth)acrylic acid, or a mixture of two or more of these, but the present invention is not limited thereto. The acrylic polymer may be a homopolymer of the monomers described above, a copolymer of two or more monomers, or a blend of each homopolymer, but the present invention is not limited thereto.

[0106] The above PVdF-based polymer may include one or more of a homopolymer of vinylidene fluoride (i.e., polyvinylidene fluoride), a copolymer of vinylidene fluoride with a monomer capable of copolymerizing with vinylidene fluoride, and a mixture thereof. As the monomer, for example, a fluorinated monomer and / or a chlorinated monomer may be used. Non-limiting examples of the fluorinated monomer include vinyl fluoride; trifluoroethylene (TrFE); chlorofluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro(alkylvinyl) ethers such as perfluoro(methylvinyl) ether (PMVE), perfluoro(ethylvinyl) ether (PEVE), and perfluoro(propylvinyl) ether (PPVE); perfluoro(1,3-dioxol); and perfluoro(2,2-dimethyl-1,3-dioxol) (PDD), and one or more of these may be included. In one embodiment of the present invention, the PVDF-based polymer may include one or more selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride-chlorofluoroethylene (PVDF-CTFE), polyvinylidene fluoride-tetrafluoroethylene (PVdF-TFE), and polyvinylidene fluoride-trifluoroethylene (PVdF-TrFE), but the present invention is not limited thereto.

[0107] In one embodiment of the present invention, when a porous coating layer containing a binder and inorganic particles is formed on the surface of a separator using the coating device, the binder and inorganic particles contained in the coating liquid tank may be used without particular limitation as long as they are intended to form a porous coating layer on the surface of the separator. For example, the binder may be the adhesive binder described above. Meanwhile, the inorganic particles are not particularly limited as long as they are electrochemically stable.

[0108] In one embodiment of the present invention, the inorganic particles are not particularly limited as long as they do not undergo oxidation and / or reduction reactions in the operating voltage range of the electrochemical device to which the separator is applied (e.g., 0 to 5 V based on Li / Li+).

[0109] In one embodiment of the present invention, the coating solution may be in the form of a suspension in which the binder and / or inorganic particles are dispersed in a dispersion medium, or a solution dissolved in a solvent, and is not particularly limited in type. For example, the dispersion medium or solvent may be water, acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, or a mixture of two or more of these, but the present invention is not limited thereto.

[0110] According to one aspect of the present invention, when the coating solution is provided to the surface-modified coating bar, it may be preferable that the coating solution is applied to the hydrophilic surface-modified area of ​​the coating bar and not to the surface-unmodified area.

[0111] According to another aspect of the present invention, when the coating solution is provided to the surface-modified coating bar, it may be preferable that the coating solution is not applied to the hydrophilic surface-modified area of ​​the coating bar, and that the coating solution is applied to the surface-unmodified area.

[0112] The area where the coating liquid is applied to the surface-modified coating bar may vary depending on the specific composition of the coating liquid, and is not specifically limited in the present invention.

[0113] According to one embodiment of the present invention, the coating device may further include a transfer unit that provides a coating substrate to a coating bar coated with the coating liquid after the coating liquid is provided to at least a portion of the surface of the coating bar.

[0114] As described above, the coating substrate may be a separator for an electrochemical device. In addition, the separator serving as the coating substrate may be of the first or second type described above, but the present invention is not limited thereto.

[0116] According to another aspect of the present invention, a method for coating a separator for an electrochemical device using the coating apparatus described above is provided.

[0117] A method for coating a separation membrane according to another aspect of the present invention is,

[0118] (S1) A step of treating at least a portion of the surface of a cylindrical coating bar, and

[0119] (S2) A step of coating a coating solution containing a binder on at least one surface of a coating substrate using the surface-treated coating bar, and

[0120] The above step (S1) includes plasma irradiation or corona irradiation on the surface of the coating bar while at least a portion of the surface of the coating bar is pattern masked.

[0121] According to one embodiment of the present invention, in step (S1), the surface of the coating bar before surface treatment is hydrophobic, and the surface of the surface-treated coating bar may be modified to be hydrophilic.

[0122] According to another embodiment of the present invention, in step (S1), the surface of the coating bar before surface treatment is hydrophilic, and the surface of the surface-treated coating bar may be modified to be hydrophobic.

[0123] In this specification, the hydrophobicity and hydrophilicity of the surface of the coating bar before and after the surface treatment are relative concepts, and the relativity of hydrophobicity and hydrophilicity may be measured according to known measurement methods of hydrophobicity / hydrophilicity, such as the magnitude of the water droplet contact angle of the surface, for example, but is not particularly limited to such measurement methods.

[0124] In one embodiment of the present invention, a coating liquid is supplied from the coating liquid tank to the surface-treated coating bar, and at least one surface of a coating substrate can be coated using the coating bar supplied with the coating liquid. At this time, the coating liquid includes a binder as described above.

[0125] In one embodiment of the present invention, as described above, the coating solution may be in the form of a dispersion in which the binder is dispersed in a dispersion medium. For example, the coating solution may be a dispersion in which the binder is dispersed in an aqueous solvent. In this case, the aqueous solvent may include, for example, water (H2O).

[0126] According to one embodiment of the present invention, when the surface of a coating bar is patterned and modified by plasma irradiation or corona irradiation while the surface of the coating bar is pattern-masked as described above, the surface modification of the coating bar is performed in a non-permanent manner, so the advantage is that the pattern on the surface of the coating bar can be changed by changing the pattern of the pattern masking part even after the coating bar has been surface-modified once.

[0128] Separator and electrochemical device

[0129] According to another aspect of the present invention, a separator for an electrochemical device is provided, wherein a binder is pattern-coated on the surface using the coating device described above.

[0130] In one embodiment of the present invention, the electrochemical element may be an example of a primary battery, a secondary battery, a supercapacitor, an electric double layer capacitor, etc. More specifically, the secondary battery may be a lithium-ion secondary battery.

[0131] Furthermore, an electrochemical device to which the above-mentioned separator is applied may be provided.

[0132] The electrochemical element described above comprises: an electrode assembly including the aforementioned separator, a first electrode and a second electrode respectively provided on both sides of the separator; an electrolyte; and a case accommodating the electrode assembly and the electrolyte.

[0133] In one embodiment of the present invention, the first electrode and the second electrode may each be an anode or a cathode. The anode and the cathode may each have an electrode active material coated on a current collector, and their size, shape, or type of active material is not particularly limited.

[0134] In one embodiment of the present invention, the electrolyte may be a conventional electrolyte depending on the type of electrochemical device being implemented or the type of the first electrode and the second electrode, and is not particularly limited in its composition.

[0135] In one embodiment of the present invention, the case may be one that is conventionally used as a battery case, and is not particularly limited in its external shape according to the use of the battery. For example, the case may be a cylindrical, prismatic, pouch, or coin type using a can.

[0136] Once the electrode assembly described above is completed, an electrochemical device can be manufactured by housing it in a case using a conventional method, injecting an electrolyte, and sealing it, wherein the electrochemical device may be, for example, a lithium secondary battery. Explanation of the symbols

[0137] 1: Coating device 10: Coating bar 20: Surface treatment section 30: Pattern masking section 301: Transmission area 302: Irtransparent area

Claims

Claim 1 A coating device comprising a cylindrical coating bar, a surface treatment unit spaced apart from the coating bar, and a pattern masking unit provided between the coating bar and the surface treatment unit, wherein the surface treatment unit comprises at least one of a plasma irradiator and a corona irradiator, and the pattern masking unit comprises a transmission region and a non-transmission region of the plasma or corona. Claim 2 A coating device according to claim 1, wherein the pattern masking part is a metal plate or a polymer film material. Claim 3 A coating device according to claim 1, wherein the pattern masking part has a pattern in which the transparent area and the non-transparent area alternate and repeat. Claim 4 A coating device according to claim 1, further comprising a coating liquid tank to provide a coating liquid to at least a portion of the surface of a surface-treated coating bar, wherein the coating liquid comprises a binder. Claim 5 A coating device according to claim 4, wherein the coating liquid further comprises inorganic particles. Claim 6 A coating apparatus according to claim 1, further comprising a transfer unit for providing a coating substrate to a coating bar on which a coating liquid is applied to at least a portion of the surface. Claim 7 A coating device according to claim 6, wherein the coating substrate is a separator for an electrochemical device. Claim 8 (S1) a step of treating at least a portion of the surface of a cylindrical coating bar, and (S2) a step of coating a coating liquid containing a binder on at least one surface of a coating substrate using the surface-treated coating bar, wherein the step (S1) comprises plasma irradiation or corona irradiation on the surface of the coating bar while at least a portion of the surface of the coating bar is pattern-masked. A method for coating a separator for an electrochemical device. Claim 9 A method for coating a separator for an electrochemical device according to claim 8, wherein in step (S1), the surface of the coating bar before surface treatment is hydrophobic, and the surface of the surface-treated coating bar is modified to be hydrophilic. Claim 10 A method for coating a separator for an electrochemical device according to claim 8, wherein the coating solution is a dispersion in which the binder is dispersed in an aqueous solvent. Claim 11 A method for coating a separation membrane according to claim 8, wherein the coating solution further comprises inorganic particles. Claim 12 A method for coating a separation membrane according to claim 8, wherein the coating substrate comprises a porous polymer substrate. Claim 13 A method for coating a separation membrane according to claim 8, wherein the coating substrate comprises a porous polymer substrate and a porous coating layer provided on at least one surface of the porous polymer substrate and comprising inorganic particles. Claim 14 A separator for an electrochemical device having at least one surface coated according to any one of claims 8 to 13, wherein the surface of the coated separator is pattern-coated with the binder.

Images