Patent Application
20250091084
The present invention relates to a die coater capable of effectively and simultaneously coating two different types of liquids on a current collector for a secondary battery.
With the increase in technology development and demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, lithium secondary batteries are widely used as an energy source for various electronic products as well as various mobile devices because of their high energy density and high operating voltage and excellent storage and lifespan characteristics.
Lithium secondary batteries use an electrode with an active material layer and an insulating layer formed on a surface of a current collector. The electrode is manufactured by applying and drying both an electrode slurry including an active material and the like and an insulating liquid including an insulating material and the like on the surface of the current collector so as to partially overlap each other at an edge of an electrode mixture layer, using a coating device such as a die coater.
Applying the electrode slurry and the insulating liquid separately in separate processes is undesirable in terms of production efficiency, and thus, in order to address this problem, a technique for simultaneously discharging the electrode slurry and the insulating liquid from a single die coater is being developed. For example, the technique of Korean Patent Registration No. 10-2035826 introduces a multi-row simultaneous coating slot die.
Such a conventional technique has a configuration of forming an independent slit for discharging an electrode slurry and an insulating liquid on a single shim for a die coater, and there is a risk that any one liquid inside the die coater leaks and the electrode slurry and the insulating liquid are mixed, or that the two liquids are mixed and discharged from an outlet of a slit, causing defects in the quality of the current collector.
The present invention is directed to providing a die coater capable of effectively and simultaneously coating two different types of liquids on a current collector for a secondary battery.
The technical problem to be solved by the present invention is not limited to the above-described problem, and other problems not mentioned can be clearly understood by a person skilled in the art from the description of the invention described below.
The present invention relates to a die coater capable of effectively and simultaneously coating two different types of liquids on a current collector for a secondary battery, and the die coater includes a lower block including a manifold configured to accommodate an electrode slurry, an upper block coupled to the lower block and including an insulating liquid inlet, and a coater shim interposed between the upper block and the lower block, wherein the coater shim includes a first coater shim in which a first slit for discharging the electrode slurry accommodated in the manifold is formed and a second coater shim in which a second slit for discharging an insulating liquid supplied through the insulating liquid inlet is formed, and the second coater shim is pressed by a fixing bolt screw-coupled to the insulating liquid inlet.
A width of the first slit may be limited by a width of the second coater shim.
In addition, a height of the first slit may correspond to a height of the first coater shim, and a height of the second slit may be less than a height of the second coater shim.
In one embodiment of the present invention, a hollow part passing through the fixing bolt in a longitudinal direction may be formed, and the insulating liquid may be supplied to the second slit through the hollow part.
In an example, the second slit may be formed in the form of a groove in the second coater shim, and may face the lower block.
In addition, an insulating liquid supply hole passing through the second coater shim may be formed on the second slit, and the fixing bolt may press the second coater shim at a position at which the hollow part is aligned with the insulating liquid supply hole.
In a specific example, the second coater shim may include a concave flow path groove open toward the lower block and having a bottom surface, the insulating liquid supply hole may be disposed in a closed end of the flow path groove, and an open end of the flow path groove may form the second slit.
In addition, the first coater shim may include a base extending along a width direction, and first and second guides protruding and extending from both ends of the base, respectively, and one side walls of the paired second coater shims may be in close contact with inner sidewalls of the first and second guides, respectively.
Accordingly, a distance between the other side walls of the paired second coater shims may correspond to a width of the first slit.
In addition, the fixing bolt may include a head part coupled to a fastening mechanism, a support part connected to the head part and having an outer diameter corresponding to a diameter of the insulating liquid inlet, a male screw part screw-coupled to a female screw part formed on the insulating liquid inlet and having a thread diameter corresponding to the outer diameter of the support part, and a pressing part having an outer diameter corresponding to a minor diameter of the female screw part formed on the insulating liquid inlet.
In addition, the second slit of the second coater shim may be firmly pressure-sealed to the lower block by a fastening force of the male screw part to the female screw part formed on the insulating liquid inlet to prevent mixing between the electrode slurry and the insulating liquid.
Meanwhile, according to another embodiment of the present invention, the die coater may further include a third coater shim including a concave U-shaped flow path groove that is open toward the lower block and has a bottom surface, wherein the insulating liquid supply hole may be disposed in a closed end of the U-shaped flow path groove. Two open ends of the U-shaped flow path groove may form third slits, a height of the third coater shim may be equal to a height of each of the first and second coater shims, and the third coater shim may be spaced apart from the first and second coater shims and disposed between the first and second guides. In addition, the fixing bolt may press the third coater shim at a position at which the hollow part is aligned with the insulating liquid supply hole of the third coater shim.
Accordingly, in another embodiment of the present invention, the first slit formed by the paired second coater shims may be divided into two parts by the third coater shim.
A die coater of the present invention having the above configuration is configured to simultaneously discharge two different types of liquids, for example, an electrode slurry and an insulating liquid, and in particular, a first slit and a second slit for discharging the electrode slurry and the insulating liquid, respectively, are physically separated from each other in the die coater.
In addition, a second coater shim forming the second slit is sealed by a separate pressing structure, so that internal mixing of the electrode slurry and the insulating liquid can be reliably prevented.
Further, by forming a hollow part passing through a fixing bolt that presses and seals the second coater shim, and supplying the insulating liquid directly to the second coater shim through the hollow part of the fixing bolt, it can minimize the likelihood that a portion at which the insulating liquid supplied from the outside and discharged through the second slit of the second coater shim is likely to leak out of a flow path.
Accordingly, the die coater of the present invention makes it possible to effectively coat two different types of liquids simultaneously on a current collector.
However, the technical effects that can be obtained through the present invention is not limited to the above-described effects, and other effects not mentioned can be clearly understood by a person skilled in the art from the description of the invention described below.
Because the following drawings attached to the present specification illustrate exemplary embodiments of the present invention and serve to facilitate understanding of the technical idea of the present invention together with the detailed description of the invention described below, the present invention should not be limitedly interpreted on the basis of the drawings.
The present invention may have various modifications and various embodiments, and thus specific embodiments thereof will be described in detail below.
However, it should be understood that the present invention is not limited to specific embodiments, and includes all modifications, equivalents or alternatives within the spirit and technical scope of the present invention.
The terms “comprise,” “include” and “have” used herein designate the presence of characteristics, numbers, steps, actions, components or members described in the specification or a combination thereof, and it should be understood that the possibility of the presence or addition of one or more other characteristics, numbers, steps, actions, components, members or a combination thereof is not excluded in advance.
In addition, when a part of a layer, film, region or plate is disposed “on” another part, this includes not only a case in which one part is disposed “directly on” another part, but a case in which still another part is interposed therebetween. In contrast, when a part of a layer, film, region or plate is disposed “under” another part, this includes not only a case in which one part is disposed “directly under” another part, but a case in which still another part is interposed therebetween. In addition, in this application, “on” may include not only a case of being disposed on an upper part but also a case of being disposed on a lower part.
The present invention relates to a die coater capable of effectively and simultaneously coating two different types of liquids on a current collector for a secondary battery.
In an example, the die coater of the present invention includes a lower block having a manifold configured to accommodate an electrode slurry, an upper block coupled to the lower block and having an insulating liquid inlet, and a coater shim interposed between the upper block and the lower block.
Here, the die coater of the present invention includes two types of coater shims: a first coater shim; and a second coater shim. The first coater shim forms a first slit for discharging the electrode slurry accommodated in the manifold of the lower block, and the second coater shim forms a second slit for discharging an insulating liquid supplied through the insulating liquid inlet of the upper block. In particular, the second coater shim, which forms the second slit for discharging the insulating liquid, is pressed by a fixing bolt screw-coupled to the insulating liquid inlet.
According to the die coater of the present invention, two different types of liquids, for example, the electrode slurry and the insulating liquid, are simultaneously discharged, and in particular, a first slit and a second slit, which discharge the electrode slurry and the insulating liquid, respectively, are physically separated from each other in the die coater, and the second coater shim forming the second slit maintains airtightness by a separate pressing structure, thereby reliably preventing the internal mixing of the electrode slurry and the insulating liquid.
Hereinafter, specific embodiments of a die coater according to the present invention will be described in detail with reference to the accompanying drawings.
As described above, the present invention relates to the die coater 10 capable of effectively and simultaneously coating two different types of liquids on a current collector for a secondary battery. The two different types of liquids may be, for example, an electrode slurry and an insulating liquid.
The die coater 10 of the present invention includes an upper block 100, a lower block 200, and a coater shim interposed between the upper block 100 and the lower block 200. In particular, in the present invention, the coater shim includes a first coater shim 310 and a second coater shim 320.
The upper block 100 includes an insulating liquid inlet 110 and is a portion occupying approximately half of the body of the die coater 10. The lower block 200 is a portion occupying the other half of the body and coupled to the upper block 100, and includes a manifold 210 configured to accommodate the electrode slurry. Here, the upper and lower portions are divided based on upper and lower portions of the drawing, and are not intended to limit an actual installation direction of the die coater 10.
For reference,
The coater shim is interposed between the upper block 100 and the lower block 200, and is interposed between the upper block 100 and the lower block 200 to form a slit having a height suitable for discharging a liquid. In addition, the coater shim serves to limit a flow direction of a liquid introduced into the die coater 10 or accommodated in the die coater 10 so that the liquid is discharged toward the slit without backflow, and also serves to seal so that the liquid does not leak to other portions other than the slit.
The present invention includes the first coater shim 310 and the second coater shim 320 as coater shims, and the first coater shim 310 and the second coater shim 320 respectively form a first slit 318 and a second slit 328 separated from each other. Specifically, the first coater shim 310 forms the first slit 318 for discharging the electrode slurry accommodated in the manifold 210 of the lower block 200, and the second coater shim 320 forms the second slit 328 for discharging the insulating liquid supplied through the insulating liquid inlet 110 of the upper block 100.
In addition, the first coater shim 310 and the second coater shim 320 have the same height, and do not vertically overlap each other. Thus, the first coater shim 310 and the second coater shim 320 lie on the same plane between the upper block 100 and the lower block 200. Thus, by a pressing force applied by fastening the upper block 100 to the lower block 200, for example, by bolt fastening (not shown), upper and lower surfaces of each of the first coater shim 310 and the second coater shim 320 are sealed by being in close contact with the upper block 100 and the lower block 200, respectively.
Here, the present invention is configured such that the second coater shim 320 is additionally pressed by a fixing bolt 400 screw-coupled to the insulating liquid inlet 110. As shown in
In order to prevent the insulating liquid from being mixed inside the die coater 10, the present invention is configured such that the second coater shim 320 tightly contacts the lower block by the fixing bolt 400 screw-coupled to the insulating liquid inlet 110 in order to prevent the internal mixing of the insulating liquid in the die coater 10. As a fastening force for the second coater shim 320 is enhanced by the additional pressing force by the fixing bolt 400, the risk of leakage of the insulating liquid is significantly reduced
Here, in the first coater shim 310, a space between the first and second guides 314 and 316 is formed as the first slit 318, and in the second coater shim 320, an open end of the flow path groove 322 in the form of a groove is formed as the second slit 328. Since a depth of the flow path groove 322 is smaller than a thickness (height) of the second coater shim 320, as a result, as shown in
Since the first coater shim 310 and the second coater shim 320 have the same height and are placed on the same plane without vertically overlapping, the width of the first slit 318 is limited by the width of the second coater shim 320.
For example, in the first embodiment illustrated in
As described above, looking at the structure of the second slit 328 formed by the second coater shim 320, since the second slit 328 is isolated from the electrode slurry in the first slit 318 by both sidewalls 324 of the second coater shim 320, and the flow path groove 322 has an upper side that is the bottom surface and a lower side in close contact with the lower block 200, as a result, the second coater shim 320 is structurally completely isolated from the electrode slurry. Furthermore, since the fastening force for the second coater shim 320 is enhanced by the fixing bolt 400 screw-coupled to the insulating liquid inlet 110, in the die coater 10 according to the present invention, the possibility of mixing two different types of liquids is significantly reduced.
In the first embodiment of the present invention, the fixing bolt 400 includes a hollow part 410 that passes therethrough in a longitudinal direction, and an insulating liquid supplied from the outside is supplied to the second slit 328 through the hollow part 410 of the fixing bolt 400. Unlike the flow path groove 322 having the bottom surface, an insulating liquid supply hole 326 is formed in the second slit 328 to pass through the second coater shim 320, and the fixing bolt 400 presses the second coater shim 320 at a position at which the internal hollow part 410 is aligned with the insulating liquid supply hole 326. That is, a central axis of the insulating liquid inlet 110 formed in the upper block 100 is concentric with the insulating liquid supply hole 326 of the second coater shim 320, and an end portion of the fixing bolt 400 presses the periphery of the insulating liquid supply hole 326 to bring the second coater shim 320 into close contact with the lower block.
In addition, the insulating liquid supply hole 326 is disposed in a closed end of the flow path groove 322, and thus, the insulating liquid supply hole 326 communicates with the flow path groove 322. Accordingly, the insulating liquid supplied to the hollow part 410 of the fixing bolt 400 flows to the flow path groove 322 of the bottom surface of the second coater shim 320 facing the lower block through the insulating liquid supply hole 326 and then is discharged to the outside through the open end of the flow path groove 322 forming the second slit 328.
The fixing bolt 400 includes a head part 420 coupled to a fastening mechanism (e.g., a wrench or the like), and a support part 430, a male screw part 440, and a pressing part 450 are continuously formed below the head part 420. The support part 430 has an outer diameter corresponding to a diameter of the insulating liquid inlet 110 and supports the fixing bolt 400 so that the fixing bolt 400 does not shake in the insulating liquid inlet 110.
The male screw part 440 is screw-coupled to a female screw part 112 formed on the insulating liquid inlet 110, and the fixing bolt 400 presses the second coater shim 320 while being moved forward by the screw-coupling of the male screw part 440. The male screw part 440 preferably has a thread diameter corresponding to the outer diameter of the support part 430 to secure maximum airtightness without interfering with insertion into the insulating liquid inlet 110.
In addition, the pressing part 450 is a part forming the end portion of the fixing bolt 400, and is in direct contact with the second coater shim 320. An outer diameter of the pressing part 450 needs to be larger than a diameter of the insulating liquid supply hole 326 of the second coater shim 320 so that a sufficient pressing force can be exerted, and needs to be designed to correspond to a minor diameter of the female screw part 112 formed on the insulating liquid inlet 110 so that pressing part 450 can be freely inserted without being caught in a female screw thread of the insulating liquid inlet 110.
As such, in the die coater 10 of the present invention, the second slit 328 of the second coater shim 320 is firmly pressure-sealed to the lower block 200 by the fastening force of the male screw part 440 of the fixing bolt 400 to the female screw part 112 formed on the insulating liquid inlet 110, thereby preventing mixing between the electrode slurry and the insulating liquid.
A second embodiment of the present invention is an embodiment suitable for a case in which a slitting process is performed after applying an electrode slurry and an insulating liquid on a current collector, which is supplied in the form of a coil, in two or more rows. That is, the second embodiment corresponds to an embodiment suitable for simultaneously applying a mixture layer composed of a structure of “insulating liquid-electrode slurry-insulating liquid” on the current collector in two or more rows.
In addition, the third coater shim 330 is spaced apart from the first and second coater shims 310 and 320 and disposed between the first and second guides 314 and 316, and the third coater shim 330 also acts as a factor to limit the width of a first slit 318, similar to the above-described second coater shim 320 that limits the substantial width of the first slit 318. Thus, the third coater shim 330 disposed in the middle of the first slit 318 causes sidewalls 334 on both sides thereof to split the electrode slurry into two streams, thereby discharging the electrode slurry in two parallel rows. A height of the third coater shim 330 corresponds to a height of each of the first and second coater shims 310 and 320.
By the arrangement of the third coater shim 330 and the two-row discharge structure of the electrode slurry, the application structure of “insulating liquid-electrode slurry-insulating liquid” is formed on the current collector in two parallel rows in the longitudinal direction of the current collector, and two current collector rolls may be obtained at a time by performing a slitting process in the middle of the parallel two rows.
Here, while the second embodiment is described as simultaneously applying an electrode slurry and an insulating liquid in two rows in parallel to an electrode body by adding one third coater shim 330, it would be obvious to a person skilled in the art that application may be performed in three or more rows by adding two or more third coater shims 330.
As above, the present invention has been described in more detail through the drawings and embodiments. However, since the configuration described in the drawings or embodiments described herein is merely one embodiment of the present invention and does not represent the overall technical spirit of the invention, it should be understood that the invention covers various equivalents, modifications, and substitutions at the time of filing of this application.
The present invention relates to a die coater useful for manufacturing a current collector for a secondary battery.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0039308 | Mar 2022 | KR | national |
The present application is a national phase entry under 35 U.S.C. § 371 of International Application PCT/KR2023/004088 filed on Mar. 28, 2023 which claims the benefit of priority based on Korean Patent Application No. 10-2022-0039308, filed on Mar. 30, 2022, all contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/004088 | 3/28/2023 | WO |
