Coating device for separator and manufacturing method of separator using same

Abstract

The present invention provides a coating device for a separator, comprising: a storage part for accommodating a coating solution; a coating roll for transferring, onto at least one surface of a substrate transported in one direction, the coating solution that was transported from the storage part; and a modular blade part for removing a part of the coating solution on the surface of the coating roll, wherein the modular blade part includes at least one blade, and the coating roll rotates in the same direction as the transportation direction of the substrate.

Description

Coating device for separator and method for manufacturing separator using the same

[0001] The present invention relates to a coating device and a method for manufacturing a separator for a lithium secondary battery using the same.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0067355, filed May 23, 2024, the entire contents of which are incorporated herein by reference.

[0003]

[0004] Recently, interest in energy storage technology has been growing. As its application expands to include energy for mobile phones, camcorders, laptops, and even electric vehicles, research and development efforts in electrochemical devices are becoming increasingly concrete. Electrochemical devices are attracting the most attention in this regard, and within this field, the development of rechargeable secondary batteries is a particular focus.

[0005] Secondary batteries are chemical batteries that utilize electrochemical reactions to continuously charge and discharge, enabling near-permanent use. They are categorized into lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and lithium secondary batteries. Among these, lithium secondary batteries dominate the secondary battery market due to their superior characteristics of high voltage and energy density compared to other types of batteries.

[0006] Lithium secondary batteries consist of an electrode assembly in which each active material is coated on a current collector, and an electrolyte is impregnated into a porous separator interposed between the positive and negative electrodes. The separator of a lithium secondary battery is manufactured by applying a coating solution that forms a porous coating layer on a porous polymer substrate and then drying the solvent.

[0007] Meanwhile, methods for applying a coating solution onto a porous polymer substrate, i.e., a substrate, include dip coating, die coating, roll coating, and comma coating, for example. Here, roll coating refers to a method of transferring a coating solution from a reservoir containing the coating solution onto a substrate. At this time, a blade may be introduced to control the coating solution applied to the coating roll. The coating roll may include engraved grooves on its surface to transfer more coating solution to the substrate, and the amount and depth of the grooves can be adjusted to control the amount of the transferred coating solution. However, in order to control the thickness, shape, and pattern of the coating, a new coating roll must be manufactured, which increases the manufacturing cost of the separator and increases the manufacturing time.

[0008] In addition, since there is a demand for a separator having various types of coating layers, such as forming coating layers with different patterns on a single substrate or controlling the thickness of the coating layer to vary along the length direction of the substrate, there is a need for the development of a coating device capable of manufacturing the same.

[0009]

[0010] The present invention was invented to solve the above-described technical problem, and specifically, it aims to provide a coating device that can change the thickness of a coating layer on a single substrate or form a coating layer having multiple patterns without replacing a coating roll.

[0011] In addition, the present invention aims to provide a method for manufacturing a separator for a lithium secondary battery in which the thickness of the coating layer is changed on one substrate or a coating layer having multiple patterns is formed.

[0012]

[0013] To achieve this purpose, according to one aspect of the present invention, a coating device of the following embodiment and a method for manufacturing a separator for a lithium secondary battery using the same are provided.

[0014] According to a first embodiment, a coating device for a separation membrane is provided, comprising: a storage unit containing a coating liquid; a coating roll for transferring the coating liquid transferred from the storage unit onto at least one surface of a substrate transferred in one direction; and a modular blade unit for removing a portion of the coating liquid on the surface of the coating roll, wherein the modular blade unit includes at least one blade, the coating roll has a plurality of grooves with an engraved pattern formed on the surface, and the coating roll rotates in the same direction as the transfer direction of the substrate.

[0015] According to a second embodiment, in the first embodiment, the blade may have a protrusion formed with a raised pattern.

[0016] According to a third embodiment, in any one of the first to second embodiments, the modular blade portion may include at least two blades.

[0017] According to a fourth embodiment, in the third embodiment, the modular blade portion may further include a blade rotation portion that enables a plurality of blades to rotate.

[0018] According to a fifth embodiment, in any one of the first to fourth embodiments, the modular blade portion may include at least two blades, and each of the at least two blades may have a protrusion formed with a different relief pattern.

[0019] According to a sixth embodiment, in any one of the first to fifth embodiments, a position adjusting unit capable of adjusting the position of the modular blade unit may be further included.

[0020] According to a seventh embodiment, in any one of the first to sixth embodiments, the modular blade portion may be arranged between a transport path of a substrate transported in one direction and a coating roll.

[0021] According to the eighth embodiment, in any one of the first to seventh embodiments, a slot die for supplying a second coating liquid onto the coating roll may be further included.

[0022] According to a ninth embodiment, a method for manufacturing a separation membrane is provided, comprising the step of applying a coating solution on a substrate using a separation membrane coating device according to any one of the first to eighth embodiments on at least one surface of the substrate.

[0023] According to the tenth embodiment, in the ninth embodiment, the gap between the coating roll and the blades facing each other may be adjusted to change the coating thickness, the coating loading amount, the coating pattern, or two or more of them.

[0024] According to the eleventh embodiment, in any one of the ninth to tenth embodiments, the step of applying the coating liquid may be to change the coating thickness, coating loading amount, coating pattern, or two or more thereof by replacing the blades of the modular blade part.

[0025] According to the twelfth embodiment, in any one of the ninth to eleventh embodiments, the step of applying the coating liquid may be to change the coating thickness, coating loading amount, coating pattern, or two or more thereof along the longitudinal direction of the substrate by adjusting the position of the modular blade over time.

[0026] According to the 13th embodiment, in any one of the 9th to 12th embodiments, before the step of applying the coating liquid, the properties of the coating liquid may be measured, and then the position of the modular blade may be adjusted according to the measured properties of the coating liquid.

[0027]

[0028] A coating device for a membrane according to one embodiment of the present invention can control the thickness, loading amount, and pattern of the coating layer on a substrate without replacing the coating roll.

[0029] A coating device for a membrane according to one embodiment of the present invention can control the thickness, loading amount, and pattern of the coating layer along the longitudinal direction of the substrate.

[0030] A coating device for a membrane according to one embodiment of the present invention can form a coating layer of various patterns by using a coating roll having a plurality of grooves of engraved patterns formed therein.

[0031] A coating device for a separator according to one embodiment of the present invention uses a coating roll having a plurality of grooves formed with an engraved pattern, thereby applying different coating solutions to the grooves and non-grooves, thereby forming coating layers of various shapes.

[0032] A coating device for a membrane according to one embodiment of the present invention uses a coating roll having a plurality of grooves of an engraved pattern formed therein, thereby facilitating quantitative control of a coating solution and providing excellent reproducibility and repeatability.

[0033] A method for manufacturing a separation membrane according to one embodiment of the present invention can control the thickness, loading amount, and pattern of the coating layer on a substrate without replacing the coating roll.

[0034] A method for manufacturing a separation membrane according to one embodiment of the present invention can control the thickness, loading amount, or pattern of the coating layer along the longitudinal direction of the substrate.

[0035]

[0036] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of ​​the present invention together with the contents of the invention described above, and therefore the present invention should not be interpreted as being limited to matters described in such drawings.

[0037] Figure 1 is a drawing schematically showing the structure of a coating device for a separation membrane according to one embodiment of the present invention.

[0038] Figure 2 is a drawing schematically showing the structure of a blade according to one embodiment of the present invention.

[0039] Figure 3 is a drawing schematically showing the structure of a blade according to one embodiment of the present invention.

[0040] FIG. 4 is a drawing schematically showing the structure of a modular blade according to one embodiment of the present invention.

[0041] FIG. 5 is a schematic drawing showing the structure of a blade with a different relief pattern according to one embodiment of the present invention.

[0042] Figure 6 is a drawing schematically showing the structure of a coating device for a separation membrane according to one embodiment of the present invention.

[0043] Figure 7 is a drawing schematically showing the structure of a coating device for a separation membrane according to one embodiment of the present invention.

[0044] Figure 8 is a drawing schematically showing the structure of a coating device for a separation membrane according to one embodiment of the present invention.

[0045] Figure 9 is a drawing illustrating the removal of a portion of a coating liquid transferred to a coating roll using a coating roll having no grooves formed on the surface and a blade having no raised patterned protrusions formed.

[0046] Figure 10 is a drawing illustrating removing a portion of a coating liquid transferred to a coating roll using a coating roll having no grooves formed on the surface and a blade having a raised pattern of protrusions formed thereon.

[0047] Figure 11 is a drawing showing the removal of a portion of the coating liquid transferred to the coating roll using a coating roll having a groove formed on the surface and a blade having no raised patterned protrusion formed.

[0048] Figure 12 is a drawing showing the removal of a portion of the coating liquid transferred to the coating roll using a coating roll having a groove formed on the surface and a blade having a raised patterned protrusion formed thereon.

[0049]

[0050] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0051] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0052] Justice

[0053] Throughout this specification, when it is said that a part "includes" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0054] Throughout this specification, the description of “A and / or B” means “A or B or both.”

[0055]

[0056] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0057]

[0058] <Coating device for separator>

[0059] The present invention provides a coating device for a separation membrane.

[0060] FIG. 1 is a drawing schematically showing the structure of a coating device (1) for a separation membrane according to one embodiment of the present invention.

[0061] Referring to FIG. 1, a coating device (1) for a membrane comprises a storage unit (100) containing a coating liquid (20); a coating roll (200) for transferring the coating liquid (20) transferred from the storage unit (100) onto at least one surface of a substrate (10) that is transferred in one direction; and a modular blade unit (300) for removing a portion of the coating liquid (20) on the surface of the coating roll (200). The modular blade unit (300) comprises at least one blade (310), and the coating roll (200) has a plurality of grooves (201) having an engraved pattern formed on the surface, and the coating roll (200) is characterized in that it rotates in the same direction as the transfer direction of the substrate (10).

[0062] A coating device (1) for a separation membrane according to one embodiment of the present invention comprises a replaceable modular blade portion (300) and a coating roll (200) having a plurality of groove portions (201) of an engraved pattern formed therein.

[0063] The coating device (1) of the present invention can form coating layers of various patterns without replacing the coating roll, compared to when using a single blade. Furthermore, since coating layers of various patterns can be formed, high-precision coating is possible, and the uniformity of the coating can be further improved.

[0064] In addition, compared to the case of using a flat-shaped coating roll, the coating roll (200) of the present invention has a clearly defined grooved portion (201) and a non-grooved portion, so that different coating liquids can be respectively loaded, thereby enabling the formation of coating layers of various shapes that are difficult to implement with a flat coating roll. In addition, since the grooved portion is formed, the loading degree of the coating liquid can be constant.

[0065] In other words, the coating device (1) of the present invention has a groove (201) formed, so that the amount of coating liquid contained is superior to that in a case where the groove (201) is not formed, and thus has excellent reproducibility. In addition, since it has a modular blade (300), the properties of the produced separation membrane can be changed simply by replacing the blade.

[0066] In one embodiment of the present invention, the modular blade unit (300) may further include a blade rotation unit (320) that allows a plurality of blades (310) to rotate. The modular blade unit (300) can rotate the plurality of blades (310) around the blade rotation unit (320).

[0067] In one embodiment of the present invention, the modular blade unit (300) has no limitations in its position and connection relationship, as long as it can remove a portion of the coating liquid of the coating roll (200). For example, the modular blade unit (300) may be connected to the outside of the storage unit (100) or may be positioned without direct connection to the storage unit (100).

[0068] The substrate (10) and coating solution (20) illustrated in each drawing are illustrated for reference only, but are not to be construed as limiting the coating device for a separation membrane of the present invention.

[0069]

[0070] FIG. 2 is a drawing schematically showing the structure of a blade (310) according to one embodiment of the present invention.

[0071] In one embodiment of the present invention, the blade (310) may have a protrusion (311) of a relief pattern formed thereon. Specifically, the blade (310) may have a protrusion (311) of a relief pattern formed on an edge facing the coating roll (200). The blade (310) may have at least one or at least two protrusions (311) formed thereon according to a desired relief pattern. In this case, the protrusion (311) can approach closer to the surface of the coating roll (200) than a non-protrusion, and more of the coating liquid that comes into contact with the protrusion (311) can be removed as the coating roll (200) rotates. Accordingly, a predetermined pattern can be formed on the coating layer.

[0072]

[0073] FIG. 3 is a drawing schematically showing the structure of a blade (310) according to one embodiment of the present invention.

[0074] In one embodiment of the present invention, the blade (310) may have a convex shape at the edge facing the coating roll (200), that is, a convex shape such that the center of the blade (310) is positioned close to the coating roll (200). When the blade (310) has the shape as described above and the surface of the coating roll (200) is smooth, the coating layer may be formed so that both edges have a thick shape based on the width direction of the substrate (10). For example, due to a sliding phenomenon occurring in the electrode active material, the ends of the electrode may be lower in height than the center. At this time, when the blade (310) has a shape as illustrated in FIG. 3, the coating layer may be formed to have a thick film thickness at both ends in the width direction, thereby compensating for this height difference.

[0075]

[0076] FIG. 4 is a drawing schematically showing the structure of a modular blade (300) according to one embodiment of the present invention.

[0077] In one embodiment of the present invention, the modular blade (300) means that at least one blade (310, 310a, 310b) can be detached. The modular blade (300) can detach blades (310, 310a, 310b) having various shapes according to a predetermined purpose.

[0078] In one embodiment of the present invention, the modular blade unit (300) may include at least two blades (310, 310a, 310b). By providing two or more blades (310, 310a, 310b) with different shapes, a coating layer with a different surface pattern can be formed on at least one surface of a substrate (10) onto which a coating liquid is transferred.

[0079] In one embodiment of the present invention, the modular blade unit (300) may further include a blade rotation unit (320) that allows a plurality of blades (310, 310a, 310b) to rotate. The modular blade unit (300) can rotate the plurality of blades (310, 310a, 310b) around the blade rotation unit (320).

[0080]

[0081] FIG. 5 is a schematic drawing showing the structure of a blade (310) with a different relief pattern according to one embodiment of the present invention.

[0082] In one embodiment of the present invention, the modular blade unit (300) includes at least two blades (310a, 310b), and the at least two blades (310a, 310b) may each have protrusions with different relief patterns formed thereon. For example, as shown in FIG. 5, the first blade (310a) and the second blade (310b) having protrusions with different relief patterns formed thereon may form coating layers with different surface patterns on at least one surface of the substrate (10) onto which the coating liquid is transferred. Specifically, by providing the first blade (310a) and the second blade (310b), coating layers with various surface patterns can be formed without replacing the coating roll.

[0083]

[0084] Figure 6 is a drawing schematically showing the structure of a coating device (1) for a separation membrane according to one embodiment of the present invention.

[0085] In one embodiment of the present invention, the coating device (1) for a separation membrane may further include a position adjusting unit (400) capable of adjusting the position of the modular blade unit (300). The position adjusting unit (400) may be connected to, for example, the outer peripheral portion of the storage unit (100) to adjust the position of the modular blade (300). The position adjusting unit (400) may adjust the position of the modular blade (300) up and down and left and right by means of a device such as a cylinder.

[0086] In one embodiment of the present invention, the position adjusting unit (400) can fix the position of the modular blade unit (300) or move it over time. For example, the position adjusting unit (400) can adjust the modular blade unit (300) to move away from the surface of the coating roll (200) over time. As a result, the thickness of the coating layer can be continuously / discontinuously changed depending on the length of the separator, thereby enabling the production of a high-quality separator.

[0087] In one embodiment of the present invention, the coating device (1) for the separation membrane may further include a measuring device (not shown) that measures the properties of the coating liquid, for example, the viscosity of the coating liquid, thereby measuring the properties of the coating liquid, and a receiving device (not shown) that adjusts the position of the modular blade (300) based on the measured data, and the position adjusting unit (400) may further include. Accordingly, the amount of the coating liquid applied on the substrate (10) may be adjusted according to the viscosity of the coating liquid.

[0088]

[0089] In one embodiment of the present invention, the modular blade unit (300) may be disposed between the transport path of the substrate (10) being transported in one direction and the coating roll (200). When the modular blade unit (300) is disposed between the transport path of the substrate (10) being transported in one direction and the coating roll (200), and specifically, when the transported substrate (10) is positioned on the side being transported to the coating roll (200), the modular blade (300) can remove a portion of the coating liquid.

[0090] In one embodiment of the present invention, the slot die (400) may further include a slot die for supplying a second coating liquid (30) onto the coating roll (200). The slot die (400) may supply the second coating liquid (30) onto the coating liquid from which a portion of the coating liquid (20) has been removed by the modular blade unit (300), as illustrated in FIG. 7, or may supply the second coating liquid (30) onto the coating liquid (20) before a portion of the coating liquid (20) has been removed by the modular blade unit (300), as illustrated in FIG. 8.

[0091] In one embodiment of the present invention, a groove (201) is formed in the coating roll (200) so that the section where the coating liquid (20) is carried can be zoned. In this case, when a second coating liquid (30) having a different composition from the coating liquid is supplied onto the coating roll (200) through a slot die (400), a coating layer having a different composition at each position can be formed using only one coating device (1) for a separation membrane.

[0092] Meanwhile, since the modular blade part (300) can have a protrusion formed, for example, in a raised pattern, the pattern of the coating layer can be controlled by adjusting the shape of the modular blade part (300) and the shape of the slot die (400).

[0093] In one embodiment of the present invention, the coating device (1) for a separator may further include a backup roll (not shown) located opposite the coating roll (200) with a substrate being transported in one direction therebetween. In this case, transfer of the coating solution onto the substrate may be facilitated.

[0094]

[0095] <Method for manufacturing a separation membrane>

[0096] The present invention provides a method for manufacturing a separation membrane.

[0097] The method for manufacturing a separation membrane of the present invention includes a step of applying a coating solution (20) onto a substrate using the aforementioned separation membrane coating device (1) on at least one surface of the substrate (20).

[0098]

[0099] In one embodiment of the present invention, the method for manufacturing a separation membrane can change the coating thickness, coating loading amount, coating pattern, or two or more of them by adjusting the gap between the coating roll (200) and the blades (310) facing each other.

[0100]

[0101] FIG. 9 is a drawing showing the removal of a portion of a coating solution (20) transferred to a coating roll (200) using a coating roll (200) on which a groove (201) is not formed on the surface and a blade (310) on which a raised pattern protrusion (311) is not formed.

[0102] Specifically, the coating liquid (20) transferred from the storage unit (100) to the surface of the coating roll (200) may exist on the coating roll (200) to a thickness of a1, and a portion of the coating liquid (20) may be removed by the blade (310) so that the coating liquid (20) may exist on the coating roll (200) to a thickness of a2 (wherein a1>a2).

[0103]

[0104] FIG. 10 is a drawing showing the removal of a portion of a coating solution (20) transferred to a coating roll (200) using a coating roll (200) that does not have a groove formed on the surface and a blade (310) that has a raised patterned protrusion (311) formed thereon.

[0105] Specifically, the coating liquid (20) transferred from the storage unit (100) on the surface of the coating roll (200) may exist on the coating roll (200) to a thickness of b1, and a portion of the coating liquid (20) may be removed by the blade (310) so that the coating liquid (20) may exist on the coating roll (200) to a portion having a thickness of b1 and a portion having a thickness of b2 (provided that b1>b2). Specifically, the portion where a portion of the coating liquid (20) is removed by the protrusion (311) of the raised pattern may have a thickness of b2, and the portion where the coating liquid (20) is not removed may have a thickness of b1 as is.

[0106] Meanwhile, the coating liquid (20) from which a portion of the coating liquid (20) on the coating roll (200) has been removed is transferred onto the substrate (10). In this case, the time for which the coating liquid flows may vary depending on the viscosity and physical properties of the coating liquid used, but after a sufficient amount of time has passed, the thickness of the coating liquid (20) on the coating roll (200) can be substantially maintained even on the substrate.

[0107]

[0108] Fig. 11 is a drawing showing the removal of a portion of the coating solution (20) transferred to the coating roll (200) using a coating roll (200) having a groove (201) formed on the surface and a blade (310) having no raised patterned protrusion formed thereon.

[0109] Specifically, the coating liquid (20) transferred from the storage unit (100) on the surface of the coating roll (200) may exist on the coating roll (200) to a thickness of c1, and a portion of the coating liquid (20) may be removed by the blade (310) so that the coating liquid (20) may exist on the coating roll (200) to a portion having a thickness of c1 and a portion having a thickness of c2 (provided that c1>c2). Specifically, the portion where the coating liquid (20) is partially removed by the blade (310) may have a thickness of c2, and the portion where the coating liquid (20) is not removed may have a thickness of c1 as is.

[0110] Meanwhile, the coating liquid (20) from which a portion of the coating liquid (20) on the coating roll (200) has been removed is transferred onto the substrate (10). In this case, the time for which the coating liquid flows may vary depending on the viscosity and physical properties of the coating liquid used, but after a sufficient amount of time has passed, the thickness of the coating liquid (20) on the coating roll (200) can be substantially maintained even on the substrate.

[0111]

[0112] Fig. 12 is a drawing showing the removal of a portion of a coating solution (20) transferred to a coating roll (200) using a coating roll (200) having a groove (201) formed on the surface and a blade (310) having a raised patterned protrusion (311) formed thereon.

[0113] Specifically, the coating liquid (20) transferred from the storage unit (100) on the surface of the coating roll (200) may exist on the coating roll (200) to a thickness of d1, and a portion of the coating liquid (20) may be removed by the blade (310) so that the coating liquid (20) may exist on the coating roll (200) in a portion having a thickness of d1 and a portion having a thickness of d2 (provided that d1>d2). Specifically, the portion where the coating liquid (20) is partially removed by the blade (310) may have a thickness of d2, and the portion where the coating liquid (20) is not removed may have a thickness of d1 as is.

[0114] Meanwhile, the coating liquid (20) from which a portion of the coating liquid (20) on the coating roll (200) has been removed is transferred onto the substrate (10). In this case, the time for which the coating liquid flows may vary depending on the viscosity and physical properties of the coating liquid used, but after a sufficient amount of time has passed, the thickness of the coating liquid (20) on the coating roll (200) can be substantially maintained even on the substrate.

[0115]

[0116] In one embodiment of the present invention, the step of applying the coating solution may change the coating thickness, coating loading amount, coating pattern, or two or more thereof by replacing the blade (310) of the modular blade unit (300). Specifically, by replacing the blade (310) of the modular blade (300), the coating thickness, coating loading amount, and / or coating pattern on one substrate (10) may be changed.

[0117]

[0118] In one embodiment of the present invention, the step of applying the coating solution can change the coating thickness, coating loading amount, coating pattern, or two or more thereof along the longitudinal direction of the substrate (10) by adjusting the position of the modular blade (300) over time. Specifically, the modular blade (300) can be positioned closer to or farther from the coating roll (200) over time to adjust the amount of the coating solution (20) positioned on the coating roll (200), thereby allowing the coating layer formed on the substrate (10) to have a different thickness along the longitudinal direction of the substrate.

[0119]

[0120] In one embodiment of the present invention, prior to the step of applying the coating liquid, the properties of the coating liquid may be measured, and then the position of the modular blade may be adjusted based on the measured properties of the coating liquid. Specifically, the properties of the coating liquid may be measured, and the position of the modular blade (300) may be adjusted based on the measured data, thereby controlling the amount of the coating liquid (20) positioned on the coating roll (200), thereby controlling the coating thickness and / or coating loading amount formed on the substrate (10).

[0121] In one embodiment of the present invention, the method for manufacturing a separation membrane can apply a second coating solution onto a coating roll using a second coating solution supply device such as a slot die, thereby forming a coating layer having a different composition depending on the location.

[0122]

[0123] In one embodiment of the present invention, the method for manufacturing a separation membrane may include a step of preparing a coating solution including a binder polymer and inorganic particles prior to the step of applying the coating solution onto a substrate.

[0124] The coating solution containing the above binder polymer and inorganic particles can be prepared by adding the binder polymer and inorganic particles to a solvent.

[0125] In one embodiment of the present invention, the solvent may be an aqueous solvent or an organic solvent.

[0126] In one embodiment of the present invention, the aqueous solvent may be water or an aqueous solvent containing water. Furthermore, when drying speed and temperature are limited, a co-solvent such as methanol, ethanol, or isopropyl alcohol, which has a lower boiling point than water, may be used.

[0127] In one embodiment of the present invention, the organic solvent is cyclic aliphatic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as toluene, xylene and ethylbenzene; ketones such as acetone, ethyl methyl ketone, diisopropyl ketone, cyclohexanone, methylcyclohexane and ethylcyclohexane; chlorinated aliphatic hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; esters such as ethyl acetate, butyl acetate, γ-butyrolactone and ε-caprolactone; acylonitrile such as acetonitrile and propionitrile; ethers such as tetrahydrofuran and ethylene glycol diethyl ether; alcohols such as methanol, ethanol, isopropanol, ethylene glycol and ethylene glycol monomethyl ether; amides such as N-methylpyrrolidone and N,N-dimethylformamide. , and the organic solvent may include acetone in consideration of the advantage in the drying process.

[0128] In one embodiment of the present invention, the organic solvent may be used alone, or a mixed solvent of two or more thereof may be used. Among these, solvents with low boiling points and high volatility are particularly preferred, as they can be removed in a short period of time and at low temperatures. Specifically, acetone, toluene, cyclohexanone, cyclopentane, tetrahydrofuran, cyclohexane, xylene, or N-methylpyrrolidone, or a mixed solvent thereof, are preferred.

[0129] In one embodiment of the present invention, the binder polymer is not particularly limited as long as it provides bonding force between inorganic particles and bonding force between the porous coating layer and the porous polymer substrate. The above binder polymer is, for example, polyvinylidene fluoride-co-hexafluoro propylene (PVDF-co-HFP), polyvinylidene fluoride-co-trichloro ethylene, polyvinylidene fluoride-co-chlorotrifluoro ethylene, poly(methyl)methacrylate, polyethyl(meth)acrylate, poly n-propyl(meth)acrylate, polyisopropyl(meth)acrylate, poly n-butyl(meth)acrylate, poly t-butyl(meth)acrylate, poly sec-butyl(meth)acrylate, polypentyl(meth)acrylate, poly 2-ethylbutyl poly(meth)acrylate, poly 2-ethylhexyl (Meth)acrylate, poly n-octyl (meth)acrylate, polyisooctyl (meth)acrylate, polyisononyl (meth)acrylate, polylauryl (meth)acrylate, polytetradecyl (meth)acrylate, poly N-vinylpyrrolidinone, polyacrylonitrile, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan,It may be cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, or two or more of these.

[0130] In one embodiment of the present invention, the inorganic particles are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles that can be used in the present invention can be used within the operating voltage range of the applied electrochemical device (e.g., Li / Li). + There is no particular limitation as long as no oxidation and / or reduction reaction occurs at a reference voltage of 0 to 5 V. In particular, when using inorganic particles with a high dielectric constant as inorganic particles, it can contribute to increasing the degree of dissociation of electrolyte salts, such as lithium salts, in the liquid electrolyte, thereby improving the ionic conductivity of the electrolyte.

[0131] For the reasons mentioned above, it is preferable that the inorganic particles include high-k inorganic particles having a dielectric constant of 5 or more, preferably 10 or more. Non-limiting examples of inorganic particles having a dielectric constant of 5 or more include BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT, 0 <x<1, 0<y<1), Pb(Mg 1 / 3 Nb 2 / 3 )O3-PbTiO3(PMN-PT), hafnia (HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, SiO2, Y2O3, Al2O3, SiC and TiO2 or mixtures thereof.

[0132] In addition, as the inorganic particles, inorganic particles having lithium ion transfer capability, i.e., inorganic particles containing lithium elements but having the function of transferring lithium ions without storing lithium, can be used. Non-limiting examples of inorganic particles having lithium ion transfer capability include lithium phosphate (Li3PO4), lithium titanium phosphate (LixTiy(PO4)3, 0 < x <2, 0 < y < 3), lithium aluminum titanium phosphate (Li x Al y Ti z (PO4)3, 0 < x < 2, 0 < y < 1, 0 < z < 3), 14Li2O-9Al2O3-38TiO2-39P2O5, etc. (LiAlTiP) x O y Series Glass (0 <x < 4, 0 < y < 13), 리튬란탄티타네이트(Li x La y TiO3, 0 < x < 2, 0 < y < 3), Li 3.25 Ge 0.25 P 0.75 Lithium germanium thiophosphate (Li) such as S4 x Ge y P z S w , 0 < x < 4, 0 < y < 1, 0 < z < 1, 0 < w < 5), lithium nitride (Li 3 N ), etc. x N y , 0 < x <4, 0 < y < 2), SiS2 series glasses such as Li3PO4-Li2S-SiS2 (Li x Si y S z , 0 < x < 3, 0 <y < 2, 0 < z < 4), LiI-Li2S-P2S5등과 같은 P2S5계열 글래스(Li x P y S z , 0 < x < 3, 0< y < 3, 0 < z < 7) or mixtures thereof.

[0133] In addition, the inorganic particles may have a particle size within the range of 3 ㎛ to 200 ㎛ at the time of injection, and when discharged into the porous polymer substrate, the D of the inorganic particles 50 There is no special limitation, but in order to form a coating layer of uniform thickness and have an appropriate porosity, it is preferably in the range of 0.1 ㎛ to 1.5 ㎛. If it is less than 0.1 ㎛, dispersibility may be reduced, and if it exceeds 1.5 ㎛, the thickness of the formed inorganic coating layer may increase.

[0134] The weight ratio of the binder polymer and the inorganic particles may be, for example, 50:50 to 99:1 or 70:30 to 95:5. When the weight ratio of the binder polymer and the inorganic particles satisfies the above-described range, the pore size and porosity of the porous coating layer may be appropriate, and the heat resistance characteristics of the separator may be better.

[0135]

[0136] In one embodiment of the present invention, the viscosity of the coating solution may be 5 cps to 30 cps, or 10 cps to 20 cps, at 23°C. When the viscosity of the coating solution satisfies the above-described range, the shape of the pattern of the coating layer may be more distinct. At this time, the viscosity may be measured using, for example, a Brookfield viscometer (DV2T viscometer, 12 rpm, spindle 24) at 23°C.

[0137]

[0138] In one embodiment of the present invention, the substrate may include, for example, polyethylene, polypropylene, polyimide, polyethylene terephthalate, polyamide, polysulfone, polyvinylidene fluoride, polyacrylonitrile, or two or more thereof.

Claims

1. A storage unit containing a coating liquid; A coating roll that transfers the coating liquid transferred from the storage unit onto at least one side of a substrate being transferred in one direction; and It includes a modular blade part that removes some of the coating liquid on the surface of the coating roll; The above modular blade section includes at least one blade, The above coating roll has a plurality of grooves with an engraved pattern formed on the surface, A coating device for a separation membrane, characterized in that the coating roll rotates in the same direction as the transport direction of the substrate.

2. In claim 1, A coating device for a membrane, characterized in that the above blade has a protrusion formed in a raised pattern.

3. In claim 1, A coating device for a membrane, characterized in that the modular blade section includes at least two blades.

4. In claim 3, A coating device for a separation membrane, characterized in that the modular blade section further includes a blade rotation section that enables a plurality of blades to rotate.

5. In claim 1, The above modular blade portion includes at least two blades, A coating device for a separator, wherein at least two of the blades are each formed with protrusions having different relief patterns.

6. In claim 1, A coating device for a separation membrane, characterized in that it further includes a position adjusting unit capable of adjusting the position of the modular blade unit.

7. In claim 1, A coating device for a separation membrane, characterized in that the modular blade section is positioned between a transport path of a material transported in one direction and a coating roll.

8. In claim 1 A coating device for a separator, characterized in that it further includes a slot die for supplying a second coating liquid onto the coating roll.

9. A method for manufacturing a separation membrane, comprising the step of applying a coating solution on a substrate using the separation membrane coating device of claim 1 on at least one side of the substrate.

10. In claim 9, A method for manufacturing a separation membrane, characterized in that the gap between the coating roll and the blades facing each other is adjusted to change the coating thickness, coating loading amount, coating pattern, or two or more of these.

11. In claim 9, A method for manufacturing a separation membrane, characterized in that the step of applying the coating solution is performed by replacing the blades of the modular blade unit to change the coating thickness, coating loading amount, coating pattern, or two or more of these.

12. In claim 9, A method for manufacturing a separation membrane, characterized in that the step of applying the coating solution changes the coating thickness, coating loading amount, coating pattern, or two or more thereof along the longitudinal direction of the substrate by adjusting the position of the modular blade over time.

13. In claim 9, A method for manufacturing a separation membrane, characterized in that, prior to the step of applying the coating solution, the properties of the coating solution are measured, and the position of the modular blade is adjusted according to the measured properties of the coating solution.

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