Slurry filtering device and separation membrane manufacturing system including the same

Abstract

A slurry filtering device and a separation membrane manufacturing system including the same are disclosed. The slurry filtering device according to one aspect of the present invention includes an accommodation structure having an accommodation space therein and a first inlet and a first outlet communicating with the accommodation space, a filter accommodated in the accommodation space and configured to filter the slurry flowing in through the first inlet and to discharge the filtered slurry to the first outlet, and an ultrasonic module at least a portion of which is disposed in the internal space of the filter and configured to generate ultrasonic vibrations inside the filter.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2022-0182926 filed on December 23, 2022, and Korean Patent Application No. 10-2023-0027312 filed on February 28, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings.

[0002] The present invention relates to a slurry filtering device and a separator manufacturing system including the same, and more particularly, to a slurry filtering device for filtering a slurry containing a coating material by using ultrasound, and a separator manufacturing system for a secondary battery including the same. [Background technology]

[0003] Generally, a secondary battery refers to a battery that can be repeatedly charged and discharged, such as a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel metal hydride battery, a nickel zinc battery, etc. Such a secondary battery can be manufactured by a process of placing an electrode assembly including a positive electrode and a negative electrode stacked with an insulating separator therebetween, and an electrolyte material in various types of cases and sealing the case.

[0004] The separator of such a secondary battery can be manufactured by coating a porous polymer substrate with a slurry containing inorganic particles and a binder polymer, followed by drying. However, if the separator coating slurry contains particles or foreign matter larger than the thickness of the separator or the thickness of the separator coating layer, there is a risk that the separator may be physically damaged or lose its insulating properties during assembly of the secondary battery, resulting in a short circuit between the electrodes. If the thickness of the separator is increased to prevent such a risk, the electrical capacity and energy density of the secondary battery will decrease.

[0005] In the conventional technology, coarse particles and foreign matter contained in the slurry are removed using a filter. However, such a conventional technology has problems in that the filter is easily clogged by the binder polymer contained in the slurry and the filter replacement cycle is short, which delays the coating process and manufacturing process using the slurry and increases costs. Summary of the Invention [Problem to be solved by the invention]

[0006] The technical problem to be solved by the present invention is to provide a slurry filtering device that can increase the continuous use time of a slurry filter and the filtering amount per unit time, thereby reducing the time and cost of coating processes and manufacturing processes using a slurry, and a separation membrane manufacturing system including such a slurry filtering device.

[0007] Another object of the present invention is to provide a slurry filtering device which facilitates management and replacement of a slurry filter, and a separation membrane production system including such a slurry filtering device.

[0008] Another object of the present invention is to provide a slurry filtering device that can ensure the durability and insulating properties of a separator for a secondary battery and enable the separator to be made thinner, thereby improving the electrical capacity and energy density of the secondary battery, and a separation membrane manufacturing system including such a slurry filtering device. [Means for solving the problem]

[0009] A slurry filtering device according to one embodiment of the present invention includes a storage structure having an internal storage space and a first inlet and a first outlet communicating with the storage space, a filter housed in the storage space and configured to filter slurry flowing in through the first inlet and discharge the filtered slurry to the first outlet, and an ultrasonic module at least a portion of which is disposed in the internal space of the filter and configured to generate ultrasonic vibrations inside the filter.

[0010] In one embodiment, the accommodating structure may include a base structure having the first inlet and the first outlet and configured to support the filter, and a cap structure that can be coupled to and separated from the base structure and is configured to couple with the base structure to form the accommodating space.

[0011] In one embodiment, the base structure may include a first insertion groove into which at least one end of the filter is inserted and seated, a second insertion groove provided on an inner surface of the first insertion groove, communicating with the first inlet, into which a second inlet provided at the one end of the filter is inserted, and a third insertion groove provided on an inner surface of the first insertion groove, communicating with the first outlet, into which a second outlet provided at the one end of the filter is inserted.

[0012] In one embodiment, the filter includes a porous structure that filters the slurry flowing in through the first inlet, and the at least a portion of the ultrasonic module may be configured to be disposed in a hollow space provided inside the porous structure.

[0013] In one embodiment, the porous structure may include a plurality of porous layers stacked on top of each other from the cavity toward the exterior of the porous structure.

[0014] In one embodiment, the pores formed in the plurality of porous layers may be configured to have smaller sizes as they are located closer to the hollow side.

[0015] In one embodiment, the filter further includes a filter housing that accommodates the porous structure therein, and the filter housing may include a second inlet communicating with the first inlet and providing the slurry flowing in through the first inlet to the porous structure, and a second outlet communicating with the first outlet and discharging the slurry filtered through the porous structure to the first outlet.

[0016] In one embodiment, the porous structure may include an opening in communication with the hollow, the opening being configured to communicate with the second outlet.

[0017] In one embodiment, the ultrasonic module may include an insertion rod having a certain length and at least one end configured to be inserted into the internal space of the filter, and at least one transducer coupled to and supported by the one end of the insertion rod to generate ultrasonic vibrations.

[0018] In one embodiment, the ultrasonic module may include a plurality of the transducers, the plurality of transducers being spaced apart from one another at predetermined intervals in the longitudinal direction of the insertion rod and coupled to the one end of the insertion rod.

[0019] In one embodiment, the ultrasonic module may further include an oscillator that generates a high-frequency electrical signal corresponding to an oscillation frequency of the at least one transducer and provides the high-frequency electrical signal to the at least one transducer.

[0020] In one embodiment, the insertion rod can be configured to be inserted into the interior space of the filter through the first outlet.

[0021] A separation membrane manufacturing system according to another aspect of the present invention includes a slurry filtering apparatus according to any of the above-described embodiments. Effect of the Invention

[0022] According to the present invention, at least a portion of the ultrasonic module is disposed in the inner space of the filter and generates ultrasonic vibration from the inside to the outside of the filter, thereby effectively preventing clogging of the innermost pores of the filter where aggregation of particles contained in the slurry most frequently occurs, thereby increasing the continuous use time of the filter and the filtering amount per unit time, and reducing the time and cost of the coating process and manufacturing process using the slurry.

[0023] In addition, by configuring the base structure and the cap structure of the accommodation structure, which are joined together to form the filter accommodation space, to be separable from each other, it is possible to facilitate management and replacement of the filter.

[0024] In addition, the porous structure of the filter that filters the slurry may include a plurality of porous layers stacked on top of each other from a hollow provided inside the porous structure toward the outside of the porous structure, thereby improving the filtering performance for particles contained in the slurry.

[0025] In addition, the pores formed in each of the plurality of porous layers are configured to have smaller diameters as they are located closer to the hollow side, thereby preventing the pores from being blocked by particles contained in the slurry and enhancing the particle dispersion effect of ultrasonic vibration.

[0026] In addition, the transducers of the ultrasonic module are arranged in the internal space of the filter, spaced apart from each other in one direction, and configured to generate ultrasonic vibrations, thereby increasing the transmission area of ​​the ultrasonic vibrations transmitted to the filter and further improving filtering performance.

[0027] In addition, by applying the slurry filtering device according to the present invention to a separation membrane manufacturing system, the time and cost of the separation membrane coating process or manufacturing process can be reduced, the durability and insulation properties of the separation membrane can be ensured, and the separation membrane can be made thinner, thereby improving the electrical capacity and energy density of the secondary battery.

[0028] Furthermore, a person having ordinary skill in the art to which the present invention pertains will understand from the following description that various embodiments of the present invention can solve various technical problems not described above. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view of a slurry filtering apparatus according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view showing the slurry filtering device shown in FIG. 1. [Diagram 3] FIG. 2 is a diagram showing the internal structure of a filter included in a slurry filtering device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of a method for manufacturing a porous structure applicable to the filter shown in FIG. 3. [Diagram 5] 2 is a cross-sectional view of the slurry filtering device shown in FIG. 1 taken along line S1-S1'. [Figure 6] FIG. 1 illustrates a separation membrane manufacturing system according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, in order to clarify the solution to the technical problem of the present invention, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, if the description of related known technologies makes the gist of the present invention unclear, the description thereof may be omitted. Furthermore, the terms used in this specification are defined in consideration of the functions of the present invention, and may vary depending on the intentions or practices of designers, manufacturers, etc. Therefore, the terms described below should be defined based on the contents of this specification as a whole.

[0031] FIG. 1 illustrates a perspective view of a slurry filtering apparatus 100 according to one embodiment of the present invention.

[0032] FIG. 2 illustrates an exploded perspective view of the slurry filtering apparatus 100 shown in FIG.

[0033] As shown in FIGS. 1 and 2, a slurry filtering apparatus 100 according to one embodiment of the present invention includes a receiving structure 110, a filter 120, and an ultrasonic module .

[0034] The receiving structure 110 has a receiving space therein and includes a first inlet 102 and a first outlet 104 communicating with the receiving space. A filter 120 for filtering slurry is accommodated in the receiving space provided inside the receiving structure 110. Slurry supplied from a predetermined slurry supplying device (not shown) and flowing in through the first inlet 102 is provided to the filter 120 accommodated in the receiving space, and the slurry filtered by the filter 120 can be discharged through the first outlet 104.

[0035] In one embodiment, the receiving structure 110 can include a base structure 112 and a cap structure 114 .

[0036] In this case, the base structure 112 of the receiving structure 110 may include a first inlet 102 and a first outlet 104, and may be configured to support the filter 120. To this end, the base structure 112 may include a first insertion groove 112a, a second insertion groove 112b, and a third insertion groove 112c.

[0037] The first insertion groove 112a may be configured to receive and seat at least one end of the filter 120.

[0038] The second insertion groove 112b may be provided on an inner surface of the first insertion groove 112a, communicate with the first inlet 102, and configured to receive a second inlet provided at the one end of the filter 120.

[0039] The third insertion groove 112c may be provided on an inner surface of the first insertion groove 112a, communicate with the first outlet 104, and configured to receive a second outlet provided at the one end of the filter 120.

[0040] For example, the lower end of the filter 120 may be inserted and seated in the first insertion groove 112a. Also, a second inlet and a second outlet protruding with a tubular structure may be provided at the lower end of the filter 120. The second inlet of the filter 120 may be inserted into the second insertion groove 112b and connected to the first inlet 102 of the accommodating structure 110, and the second outlet of the filter 120 may be inserted into the third insertion groove 112c and connected to the first outlet 104 of the accommodating structure 110.

[0041] The cap structure 114 of the receiving structure 110 can be coupled to and separated from the base structure 112 described above, and can be configured to be coupled to the base structure 112 to form a receiving space for receiving the filter 120 .

[0042] For example, the base structure 112 and the cap structure 114 of the receiving structure 110 may be configured to be coupled to each other by a screw coupling method. To this end, a screw thread may be formed on an inner surface of the first insertion groove 112a of the base structure 112, and a corresponding screw thread may be formed on an outer circumferential surface of a lower end of the cap structure 114.

[0043] In this manner, by configuring the base structure 112 and the cap structure 114 of the storage structure 110, which form a filter storage space when joined together, to be separable from each other, it is possible to facilitate management and replacement of the filter.

[0044] As will be explained again below, the filter 120 is accommodated in an accommodation space provided inside the accommodation structure 110, and is configured to filter the slurry flowing in through the first inlet 102 and discharge the filtered slurry to the first outlet 104.

[0045] The ultrasonic module 130 is at least partially disposed in the internal space of the filter 120 and configured to generate ultrasonic vibrations from the inside to the outside of the filter 120. To this end, the ultrasonic module 130 may include an oscillator 132, an insertion rod 134, and a transducer 136.

[0046] The oscillator 132 may be configured to generate a high-frequency electrical signal corresponding to an oscillation frequency of the vibrator 136 and provide the signal to the vibrator 136. The frequency of the high-frequency electrical signal generated by the oscillator 132 may fall within a range of 30 to 10,000 kHz.

[0047] The insertion rod 134 may have a certain length, and at least one end of the insertion rod 134 may be configured to be inserted into the internal space of the filter 120. The insertion rod 134 may serve as a support structure for supporting the vibrator 136. Depending on the embodiment, the insertion rod 134 may also be configured to serve as a connecting member for electrically connecting the oscillator 132 and the vibrator 136.

[0048] The insertion rod 134 may be configured to be inserted into the internal space of the filter 120 through the first outlet 104 of the accommodating structure 110. That is, the insertion rod 134 may be inserted into the internal space of the filter 120 through the first outlet 104 of the accommodating structure 110, the third insertion groove 112c of the accommodating structure 110 communicating with the first outlet 104, and the second outlet of the filter 120 inserted into the third insertion groove 112c.

[0049] The vibrator 136 may be coupled to and supported at one end of an insertion rod 134 located in the internal space of the filter 120, and configured to generate ultrasonic vibrations by a high-frequency electric signal provided from an oscillator 132. To this end, the vibrator 136 may include a piezoelectric vibrator or a magnetostrictive vibrator.

[0050] In one embodiment, the ultrasound module 130 may include a plurality of the transducers 136. In this case, the plurality of transducers 136 may be coupled to one end of an insertion rod 134 located in the internal space of the filter 120, and may be coupled to the insertion rod 134 at a predetermined interval in the longitudinal direction of the insertion rod 134. For example, the plurality of transducers 136 may be coupled to the insertion rod 134 at a predetermined interval corresponding to a range of 10 to 50 mm.

[0051] In this way, at least a portion of the ultrasonic module 130 is disposed in the internal space of the filter 120 and generates ultrasonic vibrations from the inside to the outside of the filter 120, thereby effectively preventing clogging of the innermost pores of the filter where aggregation of particles contained in the slurry most frequently occurs. As a result, the continuous use time of the filter and the filtering amount per unit time can be increased, and the time and cost of the coating process and manufacturing process using the slurry can be reduced.

[0052] In addition, the transducers of the ultrasonic module 130 are arranged in the internal space of the filter 120, spaced apart from each other at a predetermined interval in one direction, and configured to generate ultrasonic vibrations, thereby increasing the transmission area of ​​the ultrasonic vibration transmitted to the filter and further improving the filtering performance.

[0053] FIG. 3 shows the internal structure of a filter 120 included in a slurry filtering device according to one embodiment of the present invention.

[0054] As shown in FIG. 3, the filter 120 may include a filter housing 122 and a porous structure 124 .

[0055] The filter housing 122 may be configured to accommodate the porous structure 124 therein. The filter housing 122 may include a second inlet 122a, an accommodating space 122b, and a second outlet 122c.

[0056] The second inlet 122a may be configured to communicate with the first inlet 102 of the receiving structure 110 described above and provide the slurry flowing in through the first inlet 102 to the porous structure 124 received in the receiving structure 110. As described above, the second inlet 122a may have a tubular structure, protrude to the outside of the filter 120, and be inserted into the second insertion groove 112b provided in the base structure 112 of the receiving structure 110.

[0057] The receiving space 122b may be configured to receive the slurry flowing in through the porous structure 124 and the second inlet 122a.

[0058] The second outlet 122c may be configured to communicate with the first outlet 104 of the accommodating structure 110 and discharge the slurry filtered through the porous structure 124 to the first outlet 104. As described above, the second outlet 122c may have a tubular structure, protrude to the outside of the filter 120, and be inserted into the third insertion groove 112c provided in the base structure 112 of the accommodating structure 110.

[0059] The porous structure 124 may have a plurality of pores and may be configured to filter the slurry entering through the first inlet 102 of the receiving structure 110 and the second inlet 122 a of the filter housing 122 .

[0060] For this purpose, the porous structure 124 may have a hollow 124a therein and an opening 124b communicating with the hollow 124a. The opening 124b of the porous structure 124 may be configured to communicate with the second outlet 122c of the filter housing 122.

[0061] That is, the slurry filled in the receiving space 122b of the filter housing 122 is filtered by passing through the porous structure 124, and the filtered slurry is collected in the hollow 124a of the porous structure 124. The slurry collected in the hollow of the porous structure 124 can be discharged to the first outlet 104 of the receiving structure 110 through the opening 124b of the porous structure 124 and the second outlet 122c of the filter housing 122.

[0062] In this case, a portion of the ultrasonic module 130 may be disposed in a hollow 124a provided inside the porous structure 124. That is, the insertion rod 134 and the transducer 136 of the ultrasonic module 130 may be disposed in the hollow 124a of the porous structure 124.

[0063] In one embodiment, the porous structure 124 may include a plurality of porous layers stacked on top of each other from the hollow 124a toward the outside of the porous structure 124. In this case, the pores formed in the plurality of porous layers may be configured to have smaller sizes as they are closer to the hollow 124a.

[0064] FIG. 4 shows an example of a method for manufacturing a porous structure that can be applied to the filter 120 shown in FIG.

[0065] 4, the porous structure 124 may be manufactured by winding a sheet-like or film-like porous substrate PS in one direction, so that the porous structure 124 may include a plurality of porous layers stacked on top of each other from the hollow 124a toward the outside of the porous structure 124.

[0066] In this case, the pores H formed in the plurality of porous layers in , H out The pores H formed in the porous substrate PS may have a smaller size as they are closer to the hollow 124a. in , H out The size of the pores H may be gradually reduced from one end of the porous substrate PS located on the outside after winding to the other end of the porous substrate PS located on the inside after winding. That is, the size of the pores H formed on one end of the porous substrate PS may be gradually reduced from one end of the porous substrate PS located on the outside after winding to the other end of the porous substrate PS located on the inside after winding. out The size of the pores H formed on the other end side of the porous substrate PS is larger than that of the in The size of the

[0067] In this manner, the porous structure 124 of the filter 120 includes multiple porous layers stacked on top of each other from the hollow 124a provided therein toward the outside of the porous structure 124, thereby improving the filtering performance of particles contained in the slurry.

[0068] In addition, the pores formed in each of the plurality of porous layers are configured to have smaller diameters as they are closer to the hollow 124a, thereby preventing the pores from being blocked by particles contained in the slurry and enhancing the particle dispersion effect of ultrasonic vibration.

[0069] FIG. 5 shows a cross-sectional view of the slurry filtering apparatus 100 shown in FIG. 1 taken along line S1-S1'.

[0070] As shown in FIG. 5, the receiving structure 110 of the slurry filtering device 100 may include a base structure 112 and a cap structure 114 .

[0071] The base structure 112 includes a first inlet 102 and a first outlet 104, and may support a filter 120. In this case, a lower end of the filter 120 may be inserted into a first insertion groove 112a of the base structure 112 to be seated.

[0072] In addition, the second inlet 122a of the filter 120 may be inserted into the second insertion groove 112b of the base structure 112 to be connected to the first inlet 102 of the receiving structure 110. In this case, an O-ring 116 may be interposed between the second inlet 122a of the filter 120 and the second insertion groove 112b of the base structure 112 to prevent leakage of the slurry.

[0073] In addition, the second outlet 122c of the filter 120 may be inserted into the third insertion groove 112c of the accommodating structure 110 to be connected to the first outlet 104 of the accommodating structure 110. In this case, an O-ring 118 may be interposed between the second outlet 122c of the filter 120 and the third insertion groove 112c of the base structure 112 to prevent leakage of slurry.

[0074] The cap structure 114 may be coupled to the base structure 112 to form a receiving space for receiving the filter 120 .

[0075] Thereafter, the slurry supplied from a predetermined slurry supplying device (not shown) and flowing in through the first inlet 102 may be received in the receiving space 122b of the filter housing 122 through the second inlet 122a of the filter 120.

[0076] The slurry contained in the containing space 122 b of the filter housing 122 is filtered by passing through the porous structure 124 of the filter 120 , and is collected in the hollow 124 a of the porous structure 124 .

[0077] The filtered slurry collected in the hollow 124 a of the porous structure 124 can be discharged to the outside through the second outlet 122 c of the filter housing 122 and the first outlet 104 of the base structure 112 .

[0078] During the filtering process, the ultrasonic module 130 of the slurry filtering device 100 generates ultrasonic vibrations from the inside to the outside of the filter 120 to prevent clogging of the porous structure 124.

[0079] To this end, one end of an insertion rod 134 of the ultrasonic module 130 and a plurality of transducers 136 may be disposed in the hollow 124a of the porous structure 124. In this case, the insertion rod 134 may be inserted into the hollow 124a of the porous structure 124 through the first outlet 104 of the receiving structure 110 and the second outlet 122c of the filter 120.

[0080] The plurality of transducers 136 may be coupled to one end of an insertion rod 134 located in the internal space of the filter 120, and may be coupled to the insertion rod 134 at a predetermined interval in the longitudinal direction of the insertion rod 134. For example, the plurality of transducers 136 may be coupled to the insertion rod 134 at a predetermined interval corresponding to a range of 10 to 50 mm.

[0081] When the high frequency electrical signal generated by the oscillator 132 of the ultrasonic module 130 is transmitted to the plurality of transducers 136, each of the plurality of transducers 136 may generate ultrasonic vibrations by the high frequency electrical signal. In this case, the frequency of the high frequency electrical signal generated by the oscillator 132 may fall within the range of 30 to 10,000 [kHz].

[0082] FIG. 6 shows a separation membrane manufacturing system 10 according to one embodiment of the present invention.

[0083] As shown in FIG. 6, a separation membrane manufacturing system 10 according to an embodiment of the present invention may include a substrate supplying unit 12 for supplying a porous polymer substrate M, a coating unit 14 for coating the porous polymer substrate M with a coating slurry filtered by the slurry filtering device 100 according to the present invention, a drying unit 16 for drying a solvent contained in the coating slurry, and a winding unit 18 for winding up the porous polymer substrate CM having a coating layer formed thereon into a roll.

[0084] The porous polymer substrate M is a substrate in which a plurality of pores are formed. The pores are interconnected to allow gas or liquid to pass from one surface of the substrate to the other surface. As such a porous polymer substrate, a porous polymer film containing a thermoplastic resin can be used from the viewpoint of providing a shutdown function. The shutdown function refers to a function in which, when the temperature of the battery becomes high, the thermoplastic resin melts and closes the pores of the porous substrate, thereby blocking the movement of ions and preventing thermal runaway of the battery. The thermoplastic resin may have a melting point of less than about 200° C. from the viewpoint of the shutdown function.

[0085] The thickness of the porous polymer substrate is not particularly limited, but may be in the range of about 1 μm to 100 μm, or in the range of 5 μm to 50 μm, and the porosity of the porous polymer substrate is not particularly limited, but may be in the range of about 10% to 95%, or in the range of 35% to 65%.

[0086] In the porous coating layer coated on such a porous polymer substrate, inorganic particles are bound to each other by a binder polymer while in contact with each other, and interstitial volumes are formed between the inorganic particles, and the porous coating layer can have a porous structure due to the interstitial volumes.

[0087] In one embodiment, the weight ratio of binder polymer to inorganic particles in the porous coating layer may be from 99:1 to 50:50.

[0088] In the present invention, the binder polymer is not particularly limited as long as it can provide a binding force between inorganic particles and a binding force between the porous coating layer and the electrode. For example, the binder polymer may be polyvinylidene fluoride-co-hexafluoropropylene (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-ethylbutylpoly(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 acetate), cellulose acetate butyrate, cellulose acetate propionateThe polymerizable monomer may include one or more polymerizable monomers selected from the group consisting of acrylonitrile-styrene-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, sucrose, cellulose acetate, cellulose ester, cellulose acylate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxyl methyl cellulose, and polyimide.

[0089] Also, the binder polymer may be a particle-type binder polymer resin. For example, it may be an acrylic copolymer, a styrene butadiene rubber, or a mixture of two or more of them, and the acrylic copolymer may include a copolymer of ethylhexyl acrylate and methyl methacrylate, polymethylmethacrylate, polyethylhexyl acrylate, polybutylacrylate, polyacrylonitrile, a copolymer of butyl acrylate and methyl methacrylate, or a mixture of two or more of them.

[0090] In the present invention, the inorganic particles are not particularly limited as long as they are electrochemically stable. For example, the inorganic particles are not particularly limited as long as they do not undergo oxidation and / or reduction reactions within the operating voltage range of the applied electrochemical element (for example, 0 to 5 V based on Li / Li+). Non-limiting examples include ZrO2, BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb2 / 3 ) O3-PbTiO3 (PMN-PT), hafnia (HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, AlOOH, Al(OH)3, SiC, or mixtures thereof, etc. On the other hand, in addition to these, lithium phosphate (Li3PO4), lithium titanium phosphate (Li x Ti y (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), (LiAlTiP) x O y -based glass (glass) (0 < x < 4, 0 < y < 13), lithium lanthanum titanate (Li x La y TiO3, 0 < x < 2, 0 < y < 3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 < x < 4, 0 < y < 1, 0 < z < 1, 0 < w < 5), lithium nitride (Li x N y , 0 < x < 4, 0 < y < 2), SiS2-based glass (Li x Si y S z , 0 < x < 3, 0 < y < 2, 0 < z < 4), P2S5-based glass (Li x P y S z , 0 < x < 3, 0 < y < 3, 0 < z < 7), or can further contain two or more of these inorganic particles.

[0091] For reference, the slurry filtering device 100 according to the present invention can of course be applied not only to the separation membrane manufacturing system described above, but also to various coating processes using coating slurries. That is, the slurry filtering device 100 according to the present invention can also be applied to the coating process of the positive electrode or the negative electrode using a slurry.

[0092] As described above, according to the present invention, at least a portion of the ultrasonic module is disposed in the inner space of the filter and generates ultrasonic vibration from the inside to the outside of the filter, thereby effectively preventing clogging of the innermost pores of the filter where aggregation of particles contained in the slurry most frequently occurs. As a result, the continuous use time of the filter and the filtering amount per unit time can be increased, and the time and cost of the coating process and manufacturing process using the slurry can be reduced.

[0093] In addition, by configuring the base structure and the cap structure of the accommodation structure, which are joined together to form the filter accommodation space, to be separable from each other, it is possible to facilitate management and replacement of the filter.

[0094] In addition, the porous structure of the filter that filters the slurry may include a plurality of porous layers stacked on top of each other from a hollow provided inside the porous structure toward the outside of the porous structure, thereby improving the filtering performance for particles contained in the slurry.

[0095] In addition, the pores formed in each of the plurality of porous layers are configured to have smaller diameters as they are located closer to the hollow side, thereby preventing the pores from being blocked by particles contained in the slurry and enhancing the particle dispersion effect of ultrasonic vibration.

[0096] In addition, the transducers of the ultrasonic module are arranged in the internal space of the filter, spaced apart from each other in one direction, and configured to generate ultrasonic vibrations, thereby increasing the transmission area of ​​the ultrasonic vibrations transmitted to the filter and further improving filtering performance.

[0097] In addition, by applying the slurry filtering device according to the present invention to a separation membrane manufacturing system, the time and cost of the separation membrane coating process or manufacturing process can be reduced, the durability and insulation properties of the separation membrane can be ensured, and the separation membrane can be made thinner, thereby improving the electrical capacity and energy density of the secondary battery.

[0098] Furthermore, it goes without saying that the embodiments according to the present invention can solve various other technical problems in the related technical field in addition to the problems described in this specification.

[0099] The present invention has been described above with reference to specific embodiments. However, it will be clear to those skilled in the art that various modified embodiments are possible within the technical scope of the present invention. Therefore, the above disclosed embodiments should be considered from an explanatory perspective, not a limiting one. That is, the true scope of the technical idea of ​​the present invention is set forth in the claims, and all differences within the scope of the equivalents thereto should be interpreted as being included in the present invention.

Claims

1. A storage structure having an internal storage space and a first inlet and a first outlet communicating with the storage space; a filter accommodated in the accommodation space and configured to filter the slurry flowing in through the first inlet and discharge the filtered slurry to the first outlet; an ultrasonic module disposed at least in part within an interior volume of the filter and configured to generate ultrasonic vibrations within the filter.

2. The containment structure includes: a base structure configured to support the filter, the base structure including the first inlet and the first outlet; The slurry filtering device according to claim 1 , further comprising: a cap structure that is connectable to and detachable from the base structure and configured to connect to the base structure to form the receiving space.

3. The base structure includes: a first insertion groove into which at least one end of the filter is inserted and seated; a second insertion groove provided on an inner surface of the first insertion groove and communicating with the first inlet, and into which a second inlet provided at the one end of the filter is inserted; a third insertion groove provided on an inner surface of the first insertion groove, communicating with the first outlet, and into which a second outlet provided at the one end of the filter is inserted.

4. The filter includes a porous structure that filters the slurry flowing through the first inlet, 2. The slurry filtering apparatus of claim 1, wherein the at least a portion of the ultrasonic module is configured to be disposed in a hollow provided inside the porous structure.

5. 5. The slurry filtering apparatus of claim 4, wherein the porous structure includes a plurality of porous layers stacked on top of each other from the hollow toward the exterior of the porous structure.

6. The slurry filtering apparatus according to claim 5, wherein the pores formed in the plurality of porous layers are configured to have smaller sizes as they are positioned closer to the hollow side.

7. The filter further includes a filter housing that houses the porous structure therein; The filter housing comprises: a second inlet communicating with the first inlet and supplying the slurry flowing through the first inlet to the porous structure; 5. The slurry filtering device according to claim 4, further comprising: a second outlet communicating with the first outlet and discharging the slurry filtered through the porous structure to the first outlet.

8. The porous structure has an opening communicating with the hollow, 8. The slurry filtering apparatus of claim 7, wherein the opening is configured to communicate with the second outlet.

9. The ultrasonic module includes: An insertion rod having a certain length and configured such that at least one end is inserted into the interior space of the filter; 2. The slurry filtering apparatus of claim 1, further comprising: at least one transducer coupled to and supported by said one end of said insertion rod, said transducer generating ultrasonic vibrations.

10. The ultrasonic module includes a plurality of the transducers, 10. The slurry filtering device according to claim 9, wherein a plurality of vibrators are spaced apart from one another at predetermined intervals in the longitudinal direction of the insertion rod and are coupled to the one end of the insertion rod.

11. 10. The slurry filtering apparatus according to claim 9, wherein the ultrasonic module further comprises an oscillator that generates a high-frequency electrical signal corresponding to an oscillation frequency of the at least one transducer and provides the high-frequency electrical signal to the at least one transducer.

12. The slurry filtering apparatus according to claim 9, wherein the insertion rod is configured to be inserted into the inner space of the filter through the first outlet.

13. A separation membrane production system comprising the slurry filtering device according to any one of claims 1 to 12.

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