Patent Application
20240125552
The present disclosure relates to an electrode sheet drying device and a drying method for mitigating creases in a non-coated part and preventing cracks from occurring at the boundary between a non-coated part and a coated part during a drying process of an electrode sheet.
Due to the rapid increase in the use of fossil fuels, the demand for the use of alternative energy or clean energy is increasing, and as part of this, the most actively researched fields are power generation and storage fields using electrochemistry.
Currently, a secondary battery is a representative example of an electrochemical device using such electrochemical energy, and its domain of usage is gradually expanding.
Meanwhile, in order to manufacture an electrode for a secondary battery, a process of coating and drying an electrode slurry in which an electrode active material, a binder, and a solvent are mixed on a current collector is performed. Thereafter, a current collector to which an electrode slurry is applied is dried, and cut and notched to a required size to manufacture an electrode for a secondary battery.
Among the electrode manufacturing processes, the process of drying the electrode slurry requires a lot of cost and time, and the drying process affects the overall efficiency of the electrode manufacturing process.
Accordingly, the current collector in the coated part region adjacent to the lightened non-coated part supports the electrode sheet 10 and does not come into close contact with a guide roller 20 in the lower part which drives the electrode sheet, so that a current collector lifting phenomenon of a current collector being lifted upward from the guide roller 20 may be induced. In addition, such current collector lifting phenomenon may be further intensified by hot air sprayed upward from the lower hot air supply part installed in the lower part of the electrode sheet toward the electrode sheet.
In this drying process, when the coated part region adjacent to the non-coated part is dried in a lifted state, the non-coated part 11 is stretched by a high temperature, and as shown in
Therefore, in the process of drying the electrode sheet, it is necessary to develop a technology capable of solving the above problems.
An object of the present disclosure is to provide an electrode sheet drying device and a drying method capable of mitigating the occurrence of creases in the non-coated part during the drying process of an electrode sheet including a coated part and a non-coated part, and preventing a lifting of a current collector and an occurrence of cracks at the boundary between the non-coated part and the coated part.
According to the present disclosure, an electrode sheet drying device for drying an electrode slurry coated on a sheet-type current collector includes: a main body part having an accommodation space in the inside for drying, and having an inlet and an outlet; one or more guide rollers installed inside the main body part, and supports and drives an electrode sheet by its rotational motion; and a vacuum pump for applying a negative pressure to the inside of the guide roller, wherein a plurality of perforated holes is formed on the outer circumferential surface of the guide roller, so that an electrode sheet can cling to the guide roller.
In an exemplary embodiment of the present invention, each of the plurality of perforated holes may be configured to be opened and closed.
In an exemplary embodiment of the present invention, the plurality of perforated holes may be distributed over the entire outer circumferential surface of the guide roller.
The electrode sheet drying device according to the present disclosure may further include a perforated hole opening/closing controller for controlling the opening and closing motion of the perforated hole.
In an exemplary embodiment of the present invention, the guide roller may be divided into a plurality of suction zones along the longitudinal direction, and the perforated hole opening/closing controller controls the opening and closing motion of the perforated hole independently for each of the suction zone.
The electrode sheet drying device according to the present disclosure may further include a suction tube located on the lower part of the guide roller, and connected to the vacuum pump.
In an exemplary embodiment of the present invention, a partition dividing the inside of the suction tube may be provided inside the suction tube.
In an exemplary embodiment of the present invention, the suction tube may have a length corresponding to the length of the guide roller.
The electrode sheet drying device according to the present disclosure further includes a hot air supply part configured to spray hot air toward an electrode sheet.
In an exemplary embodiment of the present invention, the hot air supply part may include: a heat exchanger that heats supplied outside air; a blowing fan supplying outside air heated by the heat exchanger to the inside of the main body part; and a hot air spray nozzle installed inside the main body part, and spraying hot air toward an electrode sheet.
In an exemplary embodiment of the present invention, the vacuum pump may be connected to the heat exchanger by a circulation pipe, and air sucked through the vacuum pump may be supplied to the heat exchanger.
In an exemplary embodiment of the present invention, the diameter of the perforated hole may be 0.1 mm to 10 mm.
In addition, the present disclosure provides an electrode sheet drying method using the above drying device.
An electrode sheet drying device and a drying method according to the present disclosure has a plurality of perforated holes formed on the outer circumferential surface of a guide roller that supports and drives an electrode sheet, and as it includes a vacuum pump capable of applying a negative pressure to an inner through hole of the guide roller. As a result, when vacuum is applied, an electrode sheet transferred by the guide roller can come into close contact with the guide roller, thereby mitigating the occurrence of creases in the non-coated part, and preventing lifting of a current collector and the occurrence of cracks.
In addition, in the electrode sheet drying device according to the present disclosure, a plurality of perforated holes is generally formed on the outer circumferential surface of the guide roller, and each of the plurality of perforated holes can be opened and closed, so that a desired position along the width direction of the electrode sheet portion can selectively cling to the guide roller.
10: ELECTRODE SHEET
C: CRACK
100, 200: DRYING DEVICE
110, 210: MAIN BODY PART
20, 120, 220: GUIDE ROLLER
121, 221: PERFORATED HOLE
130, 230: VACUUM PUMP
131, 231: VACUUM PUMP PIPE
140, 240: HOT AIR SUPPLY PART
241: HEAT EXCHANGER
242: BLOWING FAN
243: HOT AIR SUPPLY NOZZLE
250: SUCTION TUBE
251: PARTITION
260: CIRCULATION PIPE
Since the present invention can apply various modifications and includes various embodiments, specific exemplary embodiments will be exemplified in the diagrams and described in detail in the description. 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 disclosure.
The terms “comprise” or “have” are used herein to 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, a film, a region or a plate, etc. 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 a third part is interposed therebetween. In contrast, when a part of a layer, a film, a region or a plate, etc. 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 a third part is interposed therebetween. In addition, in this application, “on” may include not only a case of disposed on an upper part but also a case of disposed on a lower part.
In the present specification, the x-axis corresponds to the direction in which the electrode sheet is transferred, the y-axis corresponds to the width direction of the electrode sheet and the length direction of the guide roller, and the z-axis corresponds to the direction perpendicular to the plane of the electrode sheet.
In the present disclosure, the non-coated part refers to a part of the electrode sheet to which the electrode slurry is not applied, and it is a part where the current collector is exposed.
The electrode sheet drying device according to the present disclosure is an electrode sheet drying device that dries an electrode slurry coated on a sheet-type current collector and includes: a main body part having an accommodation space in the inside for drying, and having an inlet and an outlet; one or more guide rollers installed inside the main body part, and supports and drives an electrode sheet by its rotational motion; and a vacuum pump for applying a negative pressure to the inside of a through hole of the guide roller, wherein a plurality of perforated holes is formed on the outer circumferential surface of the guide roller, so that an electrode sheet can cling to the guide roller.
When drying an electrode sheet containing a coated part coated with an electrode slurry and a non-coated part not coated with an electrode slurry, the drying speed of the coated part region adjacent to the non-coated part is faster than that of the center part region of the coated part, so that the weight of the coated part adjacent to the non-coated part becomes relatively light, leading to a phenomenon in which the electrode sheet is lifted from the lower guide roller, and accordingly, creases occurred in the non-coated part stretched in a high temperature environment, and cracks were induced at the boundary between the coated part and the non-coated part.
In order to solve the above problem, when drying the electrode sheet including the non-coated part and the coated part, the electrode sheet drying device according to the present disclosure forms a plurality of perforated holes capable of vacuum suction on the outer circumferential surface of the guide roller that supports and drives the electrode sheet, so that the electrode sheet passing on the guide roller comes into close contact with the guide roller due to the vacuum suction force, and thus the electrode sheet is not lifted from the coated part region adjacent to the non-coated part. Accordingly, the electrode sheet drying device according to the present disclosure has an effect of mitigating the occurrence of creases in the non-coated part or cracks at the boundary between the coated part and the non-coated part after drying.
Hereinafter, specific embodiments of an electrode sheet drying device according to the present disclosure will be described in detail with reference to the accompanying drawings.
Referring to these diagrams, the electrode sheet drying device 100 according to the present disclosure is largely divided into a main body part 110, a guide roller 120, and a vacuum pump 130, and a plurality of perforated holes 121 are formed on the outer circumferential surface of the guide roller 120.
The electrode sheet 10 dried by the drying device 100 of the present disclosure may include a sheet-type current collector 11, and an electrode slurry applied to one or both surfaces of the current collector 11. That is, the electrode sheet 10 of the present disclosure is prepared by coating the electrode slurry on one surface of a sheet-type current collector, and the electrode slurry 12 of the electrode sheet 10 prepared in this way is dried by the electrode drying device 100 of the present disclosure.
The main body part 110 constitutes a main frame of the electrode sheet drying device 100, and has an accommodation space S for drying in the inside. In addition, an inlet 111 into which the electrode sheet 10 to be dried is put is provided on one side of the main body part 110, and an outlet 112 is provided on the other side so that the electrode sheet 10 to be dried that has undergone a drying process can be discharged.
A drying means for drying the electrode slurry 12 is installed inside the main body part 110, and specific examples of such a drying means is a hot air spray nozzle for spraying hot air toward the electrode sheet, and a heater. One or two or more hot air spray nozzles and heaters may be installed in the upper part of the electrode sheet 10.
The guide roller 120 serves to transfer the electrode sheet 10 in one direction so that the electrode sheet 10 passes through the accommodation space S serving as a drying oven through the inlet 111 and the outlet 113.
Specifically, the guide roller 120 can rotate in one direction by receiving power from a motor (not shown), and one or more of these guide rollers 120 may be installed inside the main body part 110.
As shown in
A through hole is provided inside the guide roller 120, and when a vacuum is applied to the inside of the guide roller 120 through the through hole, the electrode sheet 10 driving on the guide roller 120 may cling to the outer circumferential surface of the guide roller 120 due to a pressure difference between the inside and the outside of the guide roller 120.
Each of the plurality of perforated holes 121 may be configured to be opened and closed.
A plurality of perforated holes 121 are generally formed on the guide roller 120, and as each of the plurality of perforated holes 121 can be opened and closed, some of the perforated holes 121 can be controlled to remain in an opened state, and the rest of the perforated hole 121 to be in a closed state, so that a region of the electrode sheet that clings to the guide roller 120 can be freely selected.
In addition, since the guide roller 120 of this embodiment can freely select the region of the electrode sheet to cling to the guide roller 120, there is an advantage in that the formation position of the perforated hole 121 does not have to be changed whenever the width of the non-coated part to which the electrode slurry is not applied, the width of the coated part to which the electrode slurry is applied, and the applying pattern of the electrode slurry, etc. are changed.
Referring to
In addition, when the electrode slurry is applied so that the coated part 12 and the non-coated part 11 alternately appear along the width direction (y-axis direction) of the electrode sheet 10, as shown in
Referring to
In addition, the guide roller 120 of the present disclosure is divided into a plurality of suction zones along the longitudinal direction (y-axis direction), and the perforated hole opening/closing controller 122 may independently control the opening and the closing motion for each of the suction zone.
Referring to
The perforated hole opening/closing controller 122 sets the perforated holes formed in a suction zone #1 and suction zone #2 to an opened state, and the perforated holes formed in the rest of the suction zones in a closed state. Since the perforated holes formed in the suction zone #1 and the suction zone #2 of the guide roller are in an opened state, the electrode sheet can cling to the guide roller through these perforated holes.
The perforated hole opening/closing controller 122 does not uniformly open and close the plurality of perforated holes 121 formed throughout the guide roller 120, but rather divides the guide roller 120 into several suction zones (#1, #2, #3 . . . #n), so that it can control the opening and closing motion of the perforated holes 121 for each suction zone. That is, only the perforated holes in the suction zone corresponding to the region where the electrode sheet needs to cling to the guide roller may be selectively controlled to be opened, and the perforated holes in the rest of the suction zones may be controlled to be closed. Accordingly, it is possible to select an suction region along the width direction (y-axis direction) of the electrode sheet 10, and since the suction force due to the application of vacuum is not transmitted to the region of the electrode sheet where suction is unnecessary, there is also an effect of preventing damage to the electrode sheet or the current collector.
During suction by a vacuum application, in order not to damage an electrode of the coated part and a current collector of the non-coated part, the perforated hole 121 preferably has a small diameter. Specifically, the range of the diameter may be 0.1 mm to 10 mm, preferably 0.2 mm to 7.5 mm, and more preferably 0.5 mm to 5 mm.
In addition, the shape of the perforated hole 121 is not particularly limited, but may be one or more selected from circular, elliptical, and polygonal shapes.
The vacuum pump 130 applies a negative pressure to the inside of the through hole of the guide roller 120. As the pressure inside the guide roller 120 is reduced by the vacuum pump 130, the electrode sheet 10 facing the guide roller 120 may cling to the outer circumferential surface of the guide roller.
The vacuum pump 130 may be installed outside of the main body part 110, and the vacuum pump 130 may apply negative pressure to the inside of the guide roller 120 through a vacuum pump pipe 131.
Referring to
The hot air supply part 140 may be installed in the upper and the lower part of the electrode sheet, respectively. The hot air supply part installed in the upper part of the electrode sheet may spray hot air with a downward current toward the electrode, and the hot air supply part installed in the lower part of the electrode sheet may spray hot air with an upward current toward the electrode.
The drying device 100 according to the present disclosure may include one or more transfer rollers for transferring an electrode sheet in the transferring direction (x-axis direction) inside the main body part 110, and some or all of these transfer rollers may be composed of the guide rollers described above.
Referring to these diagrams, the electrode sheet drying device 200 according to the second embodiment of the present invention is largely divided into a main body part 210, a guide roller 220, a vacuum pump 230, a hot air supply part 240:241,242,243, and a suction tube 250, and a plurality of perforated holes 221 is formed on the outer circumferential surface of the guide roller 220.
Since the main body part 210, the guide roller 220, the vacuum pump 230, and the hot air supply part 240 have been described in detail above, the suction tube 250 will be described in detail.
The suction tube 250 according to the present disclosure is located in the lower part of the guide roller 220, and the suction tube 250 may be mechanically coupled to the guide roller 220 so that the guide roller 220 can rotate.
The suction tube 250 may be extended along the longitudinal direction (y-axis direction) of the guide roller 220, and its length in the extension direction (y-axis direction) may correspond to the length in the longitudinal direction (x-axis direction) of the guide roller 220.
The inside of the suction tube 250 may be empty so that air can flow. One side of the suction tube 250 is directed toward the guide roller 220 in the upper part (with respect to the z-axis direction), the other side is connected to the vacuum pump pipe 231 in the lower part (with respect to the z-axis direction), and the vacuum pump pipe 231 may be connected to the vacuum pump 230 installed outside of the main body part 210.
Accordingly, when a negative pressure is applied by the vacuum pump 230, a pressure difference between the inside of the guide roller 210 and the outside of the guide roller occurs, so that the outside air is introduced to the inside of the guide roller 220 through the perforated hole 221 of the guide roller 220, and the introduced air may be sucked into the vacuum pump 230 by sequentially passing the suction tube 250 and the vacuum pump pipe 231. Also, due to the suction force of the air, the electrode sheet 10 may cling to the surface of the guide roller 220.
The suction tube 250 may be paired with the guide roller 220, so that each guide roller 220 is coupled to a single suction tube 250.
The vertical section of the suction tube 250 may have a funnel shape, and accordingly, when a vacuum is applied by the vacuum pump, a negative pressure may be more effectively generated inside the suction tube 250.
Referring to
In one specific example, the hot air supplying part 240 may include a heat exchanger 241, a blowing fan 242, and a hot air spray nozzle 243.
The heat exchanger 241 may be configured to heat the outside air supplied to the main body part 210, the blowing fan 242 may be configured to supply the outside air heated by the heat exchanger 241 to the hot air spray nozzle 243 installed inside the main body part 210, and the hot air spray nozzle 243 may be installed inside the main body part 210, and may be configured to spray hot air toward the electrode sheet 10.
After the hot air supplied into the accommodation space S of the main body part 210 is used for the electrode subjected to drying, a part of the hot air is circulated and the rest is exhausted to the outside.
In addition, in the hot air supplying part, a damper (not shown) operated by an actuator (not shown) may be installed in a duct (not shown) connected to the inside of the accommodation space S of the main body part 210. The amount of hot air supplied into the accommodation space can be adjusted through the damper.
In an exemplary embodiment of the present invention, the vacuum pump 230 may be connected to the heat exchanger 241 through a circulation pipe 260.
In this case, the air sucked through the vacuum pump 230 may be circulated to the inside of the main body part by passing the heat exchanger 241 and the blowing fan 242, thereby having an effect of saving energy.
The present disclosure provides a method for drying an electrode sheet using the above-described drying device.
The electrode sheet drying method according to an exemplary embodiment of the present invention includes:
In the negative pressure application process, all of the plurality of perforated holes may be controlled to be in an open state so that the entire region of the electrode sheet clings to the guide roller, or as described above, only the perforated holes corresponding to the portion of the electrode sheet that requires suction may be selectively controlled to be in an opened state.
The above description only illustratively described the technical idea of the present invention, so those skilled in the art to which the present disclosure pertains may make various modifications and variations without departing from the essential characteristics of the present disclosure. Therefore, the diagrams disclosed in the present disclosure are not intended to limit the technical idea of the present invention, but are for explanation, and the technical scope of the present invention is not limited by these diagrams. The scope of protection of the present invention should be interpreted by the claims below, and all technical scope within the scope equivalent thereto should be construed as being included in the scope of rights of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0184673 | Dec 2021 | KR | national |
This application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2022/020994 filed on Dec. 21, 2022, which claims the benefit of priority based on Korean Patent Application No. 10-2021-0184673 filed on Dec. 22, 2021, the disclosures of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/020994 | 12/21/2022 | WO |
