Electrode suspension supply apparatus, coating apparatus and nozzle coater

Abstract

This specification relates to an electrode suspension supply apparatus, a coating apparatus, and a die coating machine.

Description

Electrode suspension supply apparatus, coating apparatus and nozzle coater Technology sector This application claims priority over and benefit from Korean patent application no. 10-2021-0153054 filed with the Korean Intellectual Property Office on November 9, 2021. This descriptive report refers to an electrode suspension provision device, a coating device, and a nozzle coater. Background of the invention Recently, energy prices have risen due to the depletion of fossil fuels, and concern about environmental pollution is growing. Therefore, there is an increasing demand for environmentally friendly alternative energy sources. Consequently, research is continuously being conducted on various energy production technologies, such as nuclear, solar, wind, and tidal power. Furthermore, there is significant interest in energy storage devices to use the energy produced more efficiently. In particular, as the development of technologies and demands for mobile devices increase, there is a rapidly growing demand for batteries as power sources. Much research is being conducted on batteries to meet these needs. Representatively, regarding battery shape, there is high demand for angled or pouch-type secondary batteries that can be thin and used in products such as mobile phones. Regarding material, there is high demand for lithium-based secondary batteries, such as lithium-ion or lithium-polymer batteries, which offer advantages such as high energy density, discharge voltage, and output stability. In general, the secondary battery is structured to include an electrode assembly made by stacking a positive electrode, a negative electrode, and a separator located between the positive and negative electrodes. The positive and negative electrodes are manufactured by applying an electrode suspension containing an active material onto a current collector. To apply the electrode slurry, the electrode slurry is supplied through a plurality of lines branching off from a tank that stores the electrode slurry, and the coating is done for each line. In this case, studies are needed to supply the electrode suspension at a uniform flow rate for each line. Documents JP H1119566 A and CN 214600126 A disclose painting devices. Explanation of the invention Technical problem One object of this descriptive memorandum is to provide an electrode suspension provisioning device, a coating device, and a nozzle coating device. The invention is as defined by the claims. Technical solution The present invention provides an electrode suspension supply device comprising: a tank configured to accommodate electrode suspension; a main pipe having one end connected to the tank; and two or more branch pipes configured to discharge the electrode suspension introduced from the main pipe, wherein a point at which the two or more branch pipes and the main pipe are connected to each other gradually decreases as the point at which the two or more branch pipes and the main pipe are connected to each other moves further away from the tank. According to the invention, the electrode suspension provision device includes two or more pumps located at the point where the two or more branch pipes and the main pipe are connected to each other. According to the invention, the ratio of a distance A between the point where the two or more branch pipes and the main pipe are connected to each other and an end of the main pipe connected to the tank in a plane perpendicular to a gravitational direction with respect to a height difference B between the point where the two or more branch pipes and the main pipe are connected to each other and an end of the main pipe connected to the tank in the gravitational direction is from 2:1 to 3:1. In the embodiment, the main pipe includes: a connecting pipe connected to the tank; and a straight pipe coupled to the connecting pipe and connected to the two or more branch pipes. In the implementation, a defined angle between a plane perpendicular to a gravitational direction and a central axis of the straight pipe is 5 degrees or more and 25 degrees or less. Another embodiment of the present invention provides a coating device or nozzle coater configured to discharge the provided electrode slurry from the electrode slurry provisioning device. Advantageous effects The electrode slurry supply device described herein can supply the electrode slurry from a single electrode slurry tank to multiple branch pipes at a uniform flow rate, regardless of the physical properties of the electrode slurry. The electrode slurry supply device described herein can be expanded to include multiple branch pipes for each tank. Brief description of the drawings FIG. 1 is a cross-sectional view of an electrode suspension provision device in the related art. FIG. 2 is a cross-sectional view of an electrode suspension provision device according to the present descriptive report. FIG. 3 is a bottom plan view of the electrode suspension provision device according to this descriptive report. Explanation of reference numbers and symbols 1: Electrode suspension provision device 10: Tank 20: Main pipe 21: Connecting pipe 23: Straight pipe 30: Branch pipe 30': First branch pipe 30": Second branch pipe 30: Third branch pipe 30: Fourth branch pipe Preferred embodiment of the invention The present invention will be described in detail below with reference to the drawings. However, the drawings are intended to illustrate the present invention, and the scope of the present invention is not limited by them. Figure 2 is a cross-sectional view of an electrode suspension supply device 1 according to this specification, and Figure 3 is a bottom plan view of the electrode suspension supply device 1 according to this specification. The electrode suspension supply device 1 includes a tank 10, a main pipe 20, and branch pipes 30. During an electrode slurry coating process, tank 10, which supplies electrode slurry to a coating device, discharges the electrode slurry through the single main pipe 20. Main pipe 20 supplies the electrode slurry, discharged from tank 10, to the coating device (not shown) through a plurality of independently connected branch pipes 30, each connected to the pump (not shown). In this case, the type of coating device is not particularly limited, provided that the coating device can apply the electrode slurry. For example, the coating device could be a comma coater, a spin coater, or a slot nozzle coater. In this case, tank 10, main pipe 20, and branch pipe 30 of electrode suspension supply device 1 may each be made of a metallic material with a predetermined stiffness. Any material may be used as long as it can withstand the pressure generated by the electrode suspension supply. The shape of tank 10 is not limited as long as it can store the electrode slurry. Tank 10 may be cylindrical. The bottom surface of tank 10 may be convex so that the electrode slurry stored in the tank can be used efficiently. The electrode slurry stored in the tank may be discharged into the main pipeline 20 through a discharge port located at the bottom of the convex shape. As illustrated in FIG. 1, in electrode slurry dispensing device 1 in the related art, the main pipe 20 connected to the tank 10 is arranged parallel to the ground surface, and the branch pipes are all at the same height. This results in the problem that the flow rates of the electrode slurry discharged through the branch pipes differ. Specifically, the flow rate of the electrode slurry discharged from the branch pipe located relatively close to the tank is high, while the flow rate of the electrode slurry discharged from the branch pipe located relatively far from the tank is low. Furthermore, if the viscosity of the electrode slurry is too low or too high, it may not even be discharged from the branch pipe located far from the tank.This situation worsens as the amount of electrode suspension in the tank decreases. In contrast, as illustrated in FIG. 2, in the electrode suspension supply device 1 according to the present descriptive report, the main pipe 20 connected to the tank 10 is arranged obliquely so that one end of the main pipe 20 is located higher than the other end of the main pipe 20. The flow rate of the electrode suspension can be made uniform so that the electrode suspension is discharged uniformly from the branch pipes 30. The main pipe 20 may be inclined obliquely, forming an acute angle with a horizontal surface. In this case, the gradient of the main pipe 20 may be adjusted based on the electrode slurry type, viscosity, and other factors. For example, the gradient may be set to be 5 degrees or more and 25 degrees or less, or specifically, 10 degrees or more and 20 degrees or less. The main pipe 20 may include a connecting pipe 21 connected to the tank 10, and a straight pipe 23 coupled to the connecting pipe 21 and connected to the two or more branch pipes 30. In this case, a defined angle between a plane perpendicular to the gravitational direction and a central axis of the straight pipe 23 may be adjusted to be 5 degrees or more and 25 degrees or less, particularly 10 degrees or more and 20 degrees or less. One end of the main pipe 20 is connected to tank 10, and a lateral portion of the main pipe 20 is connected to at least one branch pipe 30. The electrode slurry discharged from tank 10 is transferred to the branch pipe 30 by the hydrostatic head of the electrode slurry, i.e., the pressure as a function of height. Because the main pipe 20 is arranged at an angle, the electrode slurry discharged from the tank can be transferred to the pump (not shown) in the branch pipe 30 solely by the hydrostatic head of the electrode slurry, i.e., the pressure as a function of height. Therefore, it is possible to transfer the electrode slurry at a uniform flow rate to the respective branch pipes 30. There are also level differences in height between the pumps (not illustrated) located at connection points between the main pipe 20 and the branch pipes 30, so that the electrode suspension can be discharged at the same flow rate from the respective branch pipes 30 regardless of the physical properties of the electrode suspension. The hydrostatic load of the electrode suspension, i.e., the pressure according to height, which allows the electrode suspension discharged from the tank to move to the pump (not illustrated) provided by the separate branch pipe 30, is adjusted based on a ratio of a distance A between a point where the branch pipe and the main pipe are connected to each other and an end of the main pipe connected to the tank in the plane perpendicular to the gravitational direction with respect to a height difference B between the point where the branch pipe and the main pipe are connected to each other and an end of the main pipe connected to the tank in the gravitational direction. First, an A:B ratio in the electrode suspension provision device in the related art will be described with reference to FIG.1. Because all branch pipes have the same height, B is constant, A1:B is 4:1, A2:B is 5:1, A3:B is 6:1 and A4:B is 7:1. In contrast, in electrode suspension provision device 1 according to the present invention, the ratio of the distance A between the point where the branch pipe and the main pipe are connected to each other and one end of the main pipe connected to the tank in the plane perpendicular to the gravitational direction with respect to the height difference B between the point where the branch pipe and the main pipe are connected to each other and one end of the main pipe connected to the tank in the gravitational direction is adjusted to be from 2:1 to 3:1. With reference to the A:B ratio in the electrode suspension provision device 1 according to the present descriptive memorandum illustrated in FIG.2, A1:B1, A2:B2, A3:B3 and A4:B4 are from 2:1 to 3:1, respectively. The ratio A1:B1 is a ratio of a distance A1 between a point where the first branch pipe 30' and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to the tank 10 in the plane perpendicular to the gravitational direction with respect to a height difference B1 between the point where the first branch pipe 30' and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to the tank 10 in the gravitational direction. The ratio A2:B2 is a ratio of a distance A2 between a point where the second 30" branch pipe and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to tank 10 in the plane perpendicular to the gravitational direction with respect to a height difference B2 between the point where the second 30" branch pipe and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to tank 10 in the gravitational direction. The ratio A3:B3 is a ratio of a distance A3 between a point where the third branch pipe 30 and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to the tank 10 in the plane perpendicular to the gravitational direction with respect to a height difference B3 between the point where the third branch pipe 30 and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to the tank 10 in the gravitational direction. The ratio A4:B4 is a ratio of a distance A4 between a point where the fourth branch pipe 30 and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to the tank 10 in the plane perpendicular to the gravitational direction with respect to a height difference B4 between the point where the fourth branch pipe 30 and the main pipe 20 are connected to each other and an end of the main pipe 20 connected to the tank 10 in the gravitational direction. At least one of the branch pipes 30 may be connected to the lateral portion of the main pipe 20. Specifically, the number of branch pipes 30 may be 2 or more, 3 or more, or 2 or more and 10 or fewer. Compared to the related art, the electrode slurry can be supplied at a uniform flow rate regardless of the physical properties of the electrode slurry. Therefore, the number of branch pipes, through which the electrode slurry can be supplied at a uniform flow rate from the single tank, increases compared to the related art. Another embodiment of the present invention provides a coating device configured to discharge the supplied electrode suspension from the electrode suspension supply device. The type and shape of the coating device are not particularly limited, provided that the coating device can coat the substrate with the electrode suspension by discharging the supplied electrode suspension from the electrode suspension supply device. For example, the coating device may be a comma coater, a spin coater, a slot nozzle coater, or the like. In this case, the coating device can be connected to each of the branch pipes of the electrode suspension supply device, and the coating devices connected respectively to the branch pipes are either identical or different from each other. Yet another embodiment of the present invention provides a nozzle cover configured to discharge the electrode slurry supplied from the electrode slurry supply device. The nozzle cover includes two or more nozzles, and a wedge disposed between the nozzles and configured to discharge the electrode slurry. A person skilled in the art may understand that the present invention can be carried out in other specific ways within the scope of the claims of the present invention. Therefore, the embodiments described above should be understood to be illustrative in all respects and not to limit the present invention. The scope of the present invention is represented by the claims rather than by a detailed description, and the meaning and scope of the various embodiments derived from equivalent concepts should be understood to be within the scope of the claims.

Claims

1. An electrode suspension supply device (1) comprising: a tank (10) configured to accommodate electrode suspension; a main pipe (20) having one end connected to the tank (10); and two or more branch pipes (30) configured to discharge the electrode suspension introduced from the main pipe (20), wherein a point at which the two or more branch pipes (30) and the main pipe (20) are connected to each other gradually decreases as the point at which the two or more branch pipes (30) and the main pipe (20) are connected to each other is further away from the tank (10),wherein the ratio of a distance A between the point where the two or more branch pipes (30) and the main pipe (20) are connected to each other and an end of the main pipe (20) connected to the tank (10) in a plane perpendicular to a gravitational direction with respect to a height difference B between the point where the two or more branch pipes (30) and the main pipe (20) are connected to each other and an end of the main pipe (20) connected to the tank (10) in the gravitational direction is from 2:1 to 3:1, wherein the electrode suspension provision device (1) comprises two or more pumps located at the point where the two or more branch pipes (30) and the main pipe (20) are connected to each other.

2. The electrode suspension provision device (1) of claim 1,wherein the main pipe (20) comprises: a connecting pipe (21) connected to the tank (10); and a straight pipe (23) coupled to the connecting pipe (21) and connected to the two or more branch pipes (30).

3. The electrode suspension provisioning device (1) of claim 2, wherein a defined angle between a plane perpendicular to a gravitational direction and a central axis of the straight pipe (23) is 5 degrees or more and 25 degrees or less.

4. A coating device comprising the electrode suspension provisioning device (1) of any one of claims 1 to 3, and configured to discharge electrode suspension provided from the electrode suspension provisioning device (1) of any one of claims 1 to 3.

5. A nozzle coating device comprising the electrode suspension provisioning device (1) of any one of claims 1 to 3,and configured to discharge electrode suspension provided from the electrode suspension provisioning device (1) of any one of claims 1 to 3.,

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