Method for controlling supply of electrode paste and apparatus therefor

Abstract

A method for controlling a supply amount of an electrode slurry according to one embodiment of the present disclosure comprises the steps of: supplying a slurry from a first tank to a coater; supplying the slurry to the first tank for a predetermined time from a second tank connected to the first tank when the storage amount of the slurry in the first tank decreases and the level of the first tank reaches a first predetermined level; and automatically interrupting the supply of slurry from the second tank to the first tank after a predetermined time has elapsed.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2022-0134890 filed on October 19, 2022, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0134390 filed on October 10, 2023, in the Korean Intellectual Property Office, the disclosures of which are hereby incorporated by reference in their entirety.

[0003] The present disclosure relates to a method and apparatus for controlling the supply amount of electrode slurry, and more particularly, to a method and apparatus for controlling the supply amount of electrode slurry supplied between tanks to prevent oversupply of electrode slurry and minimize temperature variation in the supplied electrode slurry. Background Art

[0004] Secondary batteries that can be repeatedly charged and discharged are used in various electronic devices. On the other hand, as the types and shapes of electronic devices are diversified, the shapes of secondary batteries mounted on electronic devices are also diversified. Recently, lithium-ion secondary batteries using lithium are often used as secondary batteries.

[0005] In order to manufacture such a secondary battery, a negative electrode coated with a negative electrode active material, a positive electrode coated with a positive electrode active material, and a separator disposed between the negative electrode and the positive electrode are required. In particular, in order to prepare the negative electrode active material and the positive electrode active material, a mixture of electrode active materials, conductive agents, binders, etc. is generally required, and the mixture is called slurry.

[0006] Specifically, in order to manufacture the positive electrode and the negative electrode, processes such as coating, drying, rolling, taping, and slitting are performed including a mixing process of mixing raw materials. In the mixing process of mixing raw materials such as electrode active materials, conductive agents, and adhesives to produce a slurry in a uniform state, heat is generated due to mixing, so that the temperature of the slurry gradually increases, and then the slurry passes through a plurality of tanks during the transfer process, accompanied by a process of adjusting the slurry temperature to a desired temperature by cooling water. The slurry formed in the mixer is transported via a storage tank, a transfer tank, etc. and is finally transported to a supply tank that supplies the slurry to a coating roller.

[0007] At this time, the temperature of the slurry affects the coating quality, loading deviation, etc. during the coating process, so controlling the temperature to an appropriate level is very important for ensuring the constant quality of the electrode. In order to adjust the slurry temperature, an impeller is usually rotated inside the tank and cooling water is supplied to the wall surface of the tank, thereby transferring heat to the outside. At this time, the temperature of the supplied coolant is adjusted so that the slurry temperature matches the target temperature, wherein a temperature control system using PID control (Proportional Integral Derivative Control) or a proportional control system using the difference between the target temperature and the current temperature can be used.

[0008] Electrode coating is performed continuously, but slurry mixing is performed once, so that the temperature of the transferred slurry has a profile with periodic high and low parts. At this time, in the case of a rapid temperature change interval, if a proportional control type of temperature regulation is used, the time required for the slurry to stabilize to the target temperature may be too long. In this case, the yield of products with desired physical properties may be affected, and in order to stabilize the temperature of the slurry, a partial stop of the process may occur, which will lead to a reduction in production.

[0009] Reference Figure 6 According to the prior art, in order to maintain a target level (e.g., 41%) of slurry storage in a supply tank, the slurry supply is started at a level (e.g., 40%) lower than the target level, and when the target level (e.g., 41%) is reached again, the slurry supply from the delivery tank is interrupted. However, due to the length of the pipeline between the supply tank and the delivery tank, if the slurry supply is interrupted at the target level, the slurry is excessively supplied compared to the desired target level. In addition, if the slurry supply from the delivery tank is started at a level (e.g., 40%) lower than the target level, due to the length of the pipeline between the supply tank and the delivery tank, while the slurry is being delivered from the delivery tank, the slurry is continuously supplied from the supply tank to the coating roller, causing the level of the supply tank to further decrease. Therefore, in the case where Figure 5 In the case of the comparative example shown, the interference becomes larger.

[0010] Therefore, in order to prevent oversupply of slurry and stabilize the temperature of the slurry, more effective automatic control of the slurry supply amount between these tanks is required. Summary of the invention

[0011] Technical issues

[0012] An object of the present disclosure is to improve a conventional electrode slurry supply system to prevent oversupply of slurry and minimize temperature variation in the slurry, thereby improving manufacturing efficiency and product quality.

[0013] However, the technical problems to be solved by the embodiments of the present disclosure are not limited to the above-mentioned problems, and various extensions can be made within the scope of the technical ideas included in the present disclosure.

[0014] Technical Solution

[0015] According to one embodiment of the present disclosure, there is provided a method for controlling the supply amount of electrode slurry, the method comprising the following steps: supplying slurry from a first tank to a coating machine; when the storage amount of slurry in the first tank decreases and the level of the first tank reaches a first predetermined level, supplying slurry from a second tank connected to the first tank to the first tank for a predetermined time; and automatically interrupting the supply of slurry from the second tank to the first tank after the predetermined time has passed.

[0016] The method may further include the step of supplying the slurry from the second tank to the first tank again for the predetermined time when the level of the first tank reaches the first predetermined level again.

[0017] The first predetermined level may be a target level of a storage amount of the slurry in the first tank.

[0018] The method may further include the following steps: during the supply of the slurry from the second tank to the first tank for the predetermined time, when the level of the first tank reaches a second predetermined level, interrupting the supply of the slurry from the second tank to the first tank, wherein the second predetermined level may be a value higher than the first predetermined level and lower than an upper limit level of the storage amount of the slurry in the first tank.

[0019] The level of the first tank may be the height or the volume of the first tank.

[0020] The slurry storage capacity of the first tank may be smaller than the slurry storage capacity of the second tank.

[0021] According to another embodiment of the present disclosure, a method for controlling a supply amount of electrode slurry is provided, the method comprising the following steps: measuring a temperature of a first tank; measuring a temperature of a second tank; and controlling a supply amount of slurry from the second tank to the first tank according to the temperature of the first tank and the temperature of the second tank.

[0022] The step of controlling the supply amount of slurry from the second tank to the first tank may include increasing the supply amount of slurry from the second tank to the first tank when the temperature of the first tank corresponds to a predetermined normal temperature range and the temperature of the second tank corresponds to the predetermined normal temperature range.

[0023] The step of controlling the supply amount of slurry from the second tank to the first tank may include maintaining the supply amount of slurry from the second tank to the first tank when the temperature of the first tank corresponds to a predetermined normal temperature range and the temperature of the second tank is higher or lower than the predetermined normal temperature range.

[0024] The step of controlling the supply amount of slurry from the second tank to the first tank may include increasing the supply amount of slurry from the second tank to the first tank when the temperature of the first tank is higher or lower than a predetermined normal temperature range and the temperature of the second tank corresponds to the predetermined normal temperature range.

[0025] The step of controlling the supply amount of slurry from the second tank to the first tank may include increasing the supply amount of slurry from the second tank to the first tank when the temperature of the first tank is higher than a predetermined normal temperature range and the temperature of the second tank is lower than the predetermined normal temperature range.

[0026] The step of controlling the supply amount of slurry from the second tank to the first tank may include increasing the supply amount of slurry from the second tank to the first tank when the temperature of the first tank is lower than a predetermined normal temperature range and the temperature of the second tank is higher than the predetermined normal temperature range.

[0027] The step of controlling the supply amount of slurry from the second tank to the first tank may include maintaining the supply amount of slurry from the second tank to the first tank when the temperature of the first tank is higher than a predetermined normal temperature range and the temperature of the second tank is higher than the predetermined normal temperature range.

[0028] The step of controlling the supply amount of slurry from the second tank to the first tank may include maintaining the supply amount of slurry from the second tank to the first tank when the temperature of the first tank is lower than a predetermined normal temperature range and the temperature of the second tank is lower than the predetermined normal temperature range.

[0029] The predetermined normal temperature range may be a temperature range preset to be suitable for slurry coating.

[0030] According to another embodiment of the present disclosure, an electrode slurry supply device for executing the method is provided, and the electrode slurry supply device includes: a coater for coating the slurry; a first tank for supplying the slurry to the coater; a second tank for storing the slurry and supplying the slurry to the first tank; a pipeline connecting the first tank and the second tank; and a valve arranged in the pipeline.

[0031] Beneficial Effects

[0032] According to the present disclosure, the amount of slurry supplied between tanks can be automatically controlled, and oversupply of slurry can be effectively prevented. In addition, the amount of slurry supplied between tanks can be adjusted in real time according to the temperature of each tank, thereby minimizing the temperature change of the slurry, stabilizing the temperature of the slurry, and maximizing the production efficiency of the electrode assembly.

[0033] Effects obtained from the present disclosure are not limited to the above-mentioned effects, and additional other effects not mentioned herein will be clearly understood by those skilled in the art from the description of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a cross-sectional view schematically showing the movement path of the slurry in the electrode manufacturing process.

[0035] Figure 2 is a diagram illustrating a process of discharging electrode slurry onto an electrode current collector positioned on a coating roller through an electrode slurry slot die.

[0036] Figure 3 is a flowchart illustrating a method for controlling a supply amount of electrode slurry according to an embodiment of the present disclosure.

[0037] Figure 4 An algorithm for controlling the supply amount of electrode slurry according to temperature according to another embodiment of the present disclosure is schematically illustrated.

[0038] Figure 5 Shown according to Figure 3 The level in the supply tank of one embodiment varies according to Figure 6 Results of experimental data comparing the level changes in the supply tanks of the prior art.

[0039] Figure 6 The level variation in a supply tank according to the prior art is shown. DETAILED DESCRIPTION

[0040] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0041] For clarity, description of parts not related to the description will be omitted, and the same reference numerals denote the same elements throughout the specification.

[0042] In addition, since the size and thickness of each element shown in the drawings are arbitrarily shown for the convenience of explanation, it is obvious that the present disclosure is not necessarily limited to those sizes and thicknesses shown in the drawings. In the drawings, the thickness is exaggerated in order to clearly show several layers and regions. In the drawings, the thickness of some layers and regions is exaggerated for the convenience of explanation.

[0043] Furthermore, it will be understood that when an element such as a layer, film, region, or plate is referred to as being "on" or "over" another element, it can be directly on the other element or intervening elements may also be present. Conversely, when an element is referred to as being "directly on" another element, this means that no other intervening elements are present. Furthermore, a portion being "on" or "over" a reference portion means that the portion is above or below the reference portion, and does not necessarily mean that the portion is "on" or "over" in the opposite direction of gravity.

[0044] In addition, throughout the application, when a part is referred to as “including” or “comprising” a certain component, it means that the part may further include other components, but does not exclude the other components, unless otherwise specified.

[0045] Furthermore, throughout the application, when referred to as a “plane”, it means when the target portion is viewed from the upper side, and when referred to as a “section”, it means when the target portion is viewed from one side of the section cut vertically.

[0046] Figure 1 This is a cross-sectional view schematically showing the movement path of the slurry in the electrode manufacturing process. Figure 2 Shown with Figure 1 The supply tank 500 is connected to the electrode slurry coating machine 600 . Figure 1 and Figure 2 The device is used to implement the method for controlling the supply amount of electrode slurry of the present disclosure.

[0047] First, refer to Figure 1 , an electrode active material, a conductive agent, a binder, etc. may be mixed in a mixer 100 to prepare a slurry. That is, the slurry is a slurry for electrode production and may include an electrode active material. The slurry may be moved to a storage tank 200, a buffer tank 300, a transfer tank 400, and a supply tank 500 in sequence. A transfer pipe may be provided to move the slurry between the various tanks.

[0048] The storage tank 200 is a tank for temporarily storing the slurry mixed and discharged from the mixer 100. The buffer tank 300 and the delivery tank 400 are tanks provided between the storage tank 200 and the supply tank 500 to continuously supply the slurry produced in one unit to the supply tank 500. The supply tank 500 is a tank for supplying the slurry to the coater 600. The storage tank 200 and / or the buffer tank 300 may be selectively omitted according to the environment in which the present invention is implemented.

[0049] Although in Figure 1 Although not specifically shown in the figure, each tank 200, 300, 400, 500 further includes a temperature sensor (not shown). A control valve (not shown) is provided in the pipeline between each tank 200, 300, 400, 500, and the control valve receives the temperature value of the electrode slurry measured by the temperature sensor and controls the flow rate of the electrode slurry. Each control valve receives the temperature value of the electrode slurry measured by the temperature sensor and controls the flow rate from the front tank to the rear tank in each section. In addition, the pipeline between each tank 200, 300, 400, 500 further includes a pump (not shown) that pumps the electrode slurry from the front tank to the rear tank.

[0050] The slurry storage capacity of the supply tank 500 may be smaller than the slurry storage capacity of the delivery tank 400. When the slurry storage capacity of the supply tank 500 is, for example, 500 L, 200 L, or 120 L, the slurry storage capacity of the delivery tank 400 may be, for example, 800 L. The present disclosure is not limited to the above, and the capacity of the supply tank 500 and the capacity of the delivery tank 400 may be variously modified and changed according to the environment in which the present invention is implemented.

[0051] Figure 2 Shown with Figure 1 The electrode slurry coater 600 is connected to the supply tank 500 of the electrode slurry coater 600. The electrode slurry coater 600 includes: an electrode slurry slit die 610 that discharges the electrode slurry supplied from the supply tank 500, and a coating roller 620 that supports and conveys the current collector layer 700. In addition, the electrode slurry coater 600 further includes a temperature sensor (not shown) that measures the temperature of the electrode slurry discharged from the electrode slurry slit die 120. The current collector layer 700 is conveyed along the coating roller 620, but the electrode slurry discharged from the electrode slurry slit die 610 is coated on one side or both sides of the current collector layer 700. After the electrode slurry is coated (Coating) on ​​the current collector 700, processes such as drying (Drying) and roll pressing (Roll Pressing) may be performed.

[0052] Figure 3 is a flowchart illustrating a method for controlling a supply amount of electrode slurry according to an embodiment of the present disclosure.

[0053] The slurry is supplied from the supply tank 500 to the coater 600 (S100). At this time, as the slurry is supplied from the supply tank 500 to the coater 600, the amount of the slurry stored in the supply tank 500 gradually decreases. Assuming that the total volume of the supply tank 500 or the total height of the supply tank 500 is 100, the amount of the slurry stored in the supply tank 500 is represented by a level (percentage) based on this.

[0054] Determine whether the storage amount of the slurry in the supply tank 500 is reduced and whether the level of the supply tank 500 reaches a first predetermined level (S200). When the storage amount of the slurry in the supply tank 500 is reduced and the level of the supply tank 500 reaches the first predetermined level, the slurry is supplied to the supply tank 500 from the delivery tank 400 connected to the supply tank 500 for a predetermined time (S300). The time for supplying the slurry from the delivery tank 400 to the supply tank 500 is a time pre-set according to the environment for implementing the present invention. For example, the time can be 3 seconds. However, the present disclosure is not limited thereto, and the time for supplying the slurry from the delivery tank 400 to the supply tank 500 can be selected and pre-set according to the type of electrode slurry, the capacity of the delivery tank 400 and / or the supply tank 500, the length of the pipeline connecting the delivery tank 400 and the supply tank 500, etc.

[0055] The first predetermined level of the supply tank 500 is a level at which supply from the delivery tank 400 to the supply tank 500 is started. The first predetermined level is a level set in advance by an operator during a process, and may be a target level of a storage amount of slurry in the supply tank 500. That is, the level may be a level at which an appropriate amount is stored in the supply tank 500 during a process, and may be modified, changed, and predetermined according to an environment in which the present invention is implemented.

[0056] The first predetermined level is selected between an upper limit level and a lower limit level of the storage amount of the slurry in the supply tank 500. The lower limit level of the storage amount of the slurry in the supply tank 500 refers to a lower limit set to prevent a problem from occurring in the process when the electrode slurry is supplied from the supply tank 500 to the coater 600 due to a possible reduction in the storage amount of the supply tank 500, thereby requiring additional slurry to be supplied from the delivery tank 400. Similarly, there is also an upper limit level of the slurry storage in the supply tank 500, which refers to an upper limit set to prevent the slurry from being oversupplied to the supply tank 500. The lower limit level and the upper limit level may also be levels pre-set by the operator according to the capacity, conditions, etc. of the supply tank 500 in the corresponding process.

[0057] On the other hand, when the storage amount of the slurry in the supply tank 500 is less than the target level, if the valve between the supply tank 500 and the delivery tank 400 is turned on and opened in order to adjust the storage amount of the slurry in the supply tank 500 to the target level, the slurry movement takes time due to the length of the pipe between the supply tank 500 and the delivery tank 400, and thus the slurry cannot be immediately supplied to the supply tank 500. Therefore, the first predetermined level of the supply tank 500 at which the valve between the supply tank 500 and the delivery tank 400 is turned on and opened may be the target level of the slurry storage in the supply tank 500. However, the present disclosure is not necessarily limited thereto, and the operator may pre-set the first predetermined level according to the environment in which the present invention is applied.

[0058] It is important to note that when the storage amount of the slurry in the supply tank 500 reaches a first predetermined level, a process of turning on and opening the valve between the supply tank 500 and the delivery tank 400 and supplying the slurry from the delivery tank 400 to the supply tank 500 for the predetermined time is performed. When the predetermined time has passed, the supply of slurry from the delivery tank 400 to the supply tank 500 is automatically interrupted (S400).

[0059] Therefore, even if the valve between the supply tank 500 and the delivery tank 400 is turned off and closed, it takes time for the slurry to move to the supply tank 500 due to the length of the pipe between the supply tank 500 and the delivery tank 400. Therefore, the problem that the slurry is continuously supplied to the supply tank 500 that has reached the upper limit level can be prevented.

[0060] Therefore, when the predetermined time has passed, the slurry supply from the delivery tank 400 to the supply tank 500 is automatically interrupted, which prevents in advance the possibility of interference caused by the continuous supply of slurry to the supply tank 500. When the level of the supply tank 500 reaches the first predetermined level again as described above, the step of supplying the slurry from the delivery tank 400 to the supply tank 500 for a predetermined time is repeated (S300). Similarly, when the predetermined time has passed, the slurry supply from the delivery tank 400 to the supply tank 500 is automatically interrupted (S400).

[0061] Of course, when the slurry is supplied from the delivery tank 400 to the supply tank 500 (S300), if the level of the supply tank 500 reaches the second predetermined level even before the predetermined time has passed, the method further includes interrupting the supply of the slurry from the delivery tank 400 to the supply tank 500. The second predetermined level may be preset to a value that is higher than the first predetermined level and lower than an upper limit level of the storage amount of the slurry in the supply tank 500.

[0062] Figure 4An algorithm for controlling the supply amount of electrode slurry according to temperature according to another embodiment of the present disclosure is schematically shown. More specifically, this is an algorithm for controlling the amount of slurry supplied from the delivery tank 400 to the supply tank 500 according to the temperature of the delivery tank 400 and the temperature of the supply tank 500. When the temperature difference between the delivery tank 400 and the supply tank 500 is large, the level of the supply tank 500 is reduced to facilitate the temperature change, or the minimum level of supply is provided to reduce interference. This is an algorithm that gradually increases the amount supplied to the supply tank 500 (i.e., increases the volume of slurry at the same temperature) when the temperature deviation is small, thereby reducing the impact of future interference.

[0063] First, the method for controlling the supply amount of electrode slurry according to the present disclosure further includes a step of measuring the temperature of the supply tank 500 and a step of measuring the temperature of the delivery tank 400 .

[0064] In addition, the step (S300) of supplying the slurry from the delivery tank 400 to the supply tank 500 for a predetermined time includes the step of controlling the supply amount of the slurry from the delivery tank 400 to the supply tank 500 according to the temperature of the supply tank 500 and the temperature of the delivery tank 400. At this time, in step S300, it is determined whether the temperature of the supply tank 500 and the temperature of the delivery tank 400 are each within a predetermined normal temperature range.

[0065] Here, the predetermined normal temperature range refers to a target temperature range pre-set by an operator in the electrode manufacturing process. For example, if the temperature of the slurry is within the corresponding normal temperature range (target temperature range), it refers to a temperature range desired by the operator, such as a temperature range that can keep the quality of the electrode constant and reduce the defective rate. The predetermined normal temperature range can be modified or changed and predetermined according to the environment in which the present invention is implemented.

[0066] At this time, a specific algorithm for controlling the amount of slurry supplied from the delivery tank 400 to the supply tank 500 is as follows.

[0067] 1-1. When the temperature of the supply tank 500 corresponds to the predetermined normal temperature range and the temperature of the delivery tank 400 corresponds to the predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is increased.

[0068] In other words, when the temperature of the supply tank 500 and the temperature of the delivery tank 400 are both within the normal temperature range, the amount of slurry supplied from the delivery tank 400 to the supply tank 500 is increased, which makes it possible to hold more slurry in a normal state in the supply tank 500 directly connected to the coater 600.

[0069] 1-2. When the temperature of the supply tank 500 corresponds to a predetermined normal temperature range and the temperature of the delivery tank 400 is higher or lower than the predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is maintained. In other words, if more slurry at an abnormal temperature than necessary is supplied to the supply tank 500, the disturbance caused by the temperature change of the slurry increases, and therefore, the supply amount is maintained at a minimum amount sufficient to maintain the consumption of the slurry in the supply tank 500.

[0070] At this time, although the temperature of the delivery tank 400 is not within the normal temperature range, if the slurry is not supplied from the delivery tank 400 to the supply tank 500, a problem may occur during the process of supplying the slurry from the supply tank 500 to the coater 600 to coat the electrode slurry. In addition, according to the present disclosure, the slurry is not supplied indefinitely from the delivery tank 400 to the supply tank 500, but is supplied only for a predetermined time as described above. The slurry supplied from the delivery tank 400 to the supply tank 500 is combined with the slurry previously stored in the supply tank 500, and therefore, the temperature change in the supply tank 500 is not relatively large.

[0071] 2-1. When the temperature of the supply tank 500 is higher or lower than a predetermined normal temperature range and the temperature of the delivery tank 400 corresponds to a predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is increased. In other words, although the temperature of the supply tank 500 is within the abnormal temperature range, the amount of slurry supplied from the delivery tank 400 within the normal temperature range may be increased, so that the temperature of the slurry in the supply tank 500 may change toward a relatively normal temperature range.

[0072] 2-2. (a) When the temperature of the supply tank 500 is higher than the predetermined normal temperature range and the temperature of the delivery tank 400 is lower than the predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is increased. In other words, the temperature of the slurry stored in the supply tank 500 and the temperature of the slurry supplied from the delivery tank 400 offset each other and become a balanced state, so that the temperature of the slurry in the supply tank 500 can be stabilized.

[0073] 2-2. (b) When the temperature of the supply tank 500 is lower than the predetermined normal temperature range and the temperature of the delivery tank 400 is higher than the predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is increased. In other words, the temperature of the slurry stored in the supply tank 500 and the temperature of the slurry supplied from the delivery tank 400 offset each other and become a balanced state, so that the temperature of the slurry in the supply tank 500 can be stabilized.

[0074] 2-3. (a) When the temperature of the supply tank 500 is higher than a predetermined normal temperature range and the temperature of the delivery tank 400 is higher than a predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is maintained. In other words, if more slurry at an abnormal temperature than necessary is supplied to the supply tank 500, the disturbance caused by the temperature change of the slurry increases, and thus the supply amount is maintained at a minimum amount sufficient to maintain the consumption of the slurry in the supply tank 500.

[0075] 2-3. (b) When the temperature of the supply tank 500 is lower than a predetermined normal temperature range and the temperature of the delivery tank 400 is lower than a predetermined normal temperature range, the supply amount of the slurry from the delivery tank 400 to the supply tank 500 is maintained. In other words, if more slurry at an abnormal temperature than necessary is supplied to the supply tank 500, the disturbance caused by the temperature change of the slurry increases, and thus the supply amount is maintained at a minimum amount sufficient to maintain the consumption of the slurry in the supply tank 500.

[0076] In the case of 2-3 (a) and 2-3 (b), as described in the case 1-2 above, if the slurry is not supplied from the delivery tank 400 to the supply tank 500 because the temperature of the delivery tank 400 is not within the normal temperature range, a problem may occur during the process of supplying the slurry from the supply tank 500 to the coater 600 to coat the electrode slurry. Therefore, the supply amount is maintained at a minimum amount sufficient to maintain the consumption of the slurry in the supply tank 500.

[0077] The predetermined normal temperature range is a temperature range that is preset in order to be suitable for slurry coating, and may be preset in various ways according to the environment in which the present invention is implemented and the type of slurry.

[0078] In one embodiment, the predetermined normal temperature range may be set within a range of, for example, 23° C. to 33° C. Alternatively, the predetermined normal temperature range may be set within a range of 23° C. to 26° C., for example, 23° C.

[0079] On the other hand, the electrode to be manufactured in the present disclosure is an electrode for a secondary battery. In addition, electrode slurry generally refers to a composition in a slurry state containing an electrode active material. The positive electrode or negative electrode refers to an electrode for a secondary battery, specifically, an electrode for a lithium secondary battery.

[0080] In one embodiment, the electrode refers to a positive electrode and / or a negative electrode of a lithium secondary battery.

[0081] The positive electrode has a structure in which two positive electrode active material layers are laminated on a positive electrode current collector. In one example, the positive electrode active material layer includes a positive electrode active material, a conductive material and a binder polymer, and may further include a positive electrode additive commonly used in the art if necessary.

[0082] The positive electrode active material may be a lithium-containing oxide, and may be the same or different. As the lithium-containing oxide, a lithium-containing transition metal oxide may be used.

[0083] For example, the lithium-containing transition metal oxide may be selected from the group consisting of Li x CoO2 (0.5 < x < 1.3), Li x NiO2 (0.5 < x < 1.3), Li x MnO2 (0.5 < x < 1.3), Li x Mn2O4 (0.5 < x < 1.3), Li x (Ni a Co b Mn c )O2 (0.5 < x < 1.3, 0 < a < 1, 0 < b < 1, 0 < c < 1, a + b + c = 1), Li x Ni 1-y Co y O2 (0.5 < x < 1.3, 0 < y < 1), Li x Co 1-y Mn y O2 (0.5 < x < 1.3, 0 ≤ y < 1), Li x Ni 1-y Mn y O2 (0.5 < x < 1.3, O ≤ y < 1), Li x (Ni a Co b Mn c )O4 (0.5 < x < 1.3, 0 < a < 2, 0 < b < 2, 0 < c < 2, a + b + c = 2), Li x Mn 2-z Ni z O4 (0.5 < x < 1.3, 0 < z < 2), Li x Mn 2-z Co z O4 (0.5 < x < 1.3, 0 < z < 2), Li x CoPO4 (0.5 < x < 1.3) and any one of the group consisting of Li x FePO4 (0.5 < x < 1.3) or a mixture of two or more of them. The lithium-containing transition metal oxide may be coated with a metal such as aluminum (Al) or a metal oxide. In addition, in addition to the lithium-containing transition metal oxide, one or more selected from the group consisting of sulfide, selenide, halide, etc. may be used.

[0084] The positive electrode active material layer may contain 94.0 to 98.5 wt % of the positive electrode active material. When the content of the positive electrode active material satisfies the above range, it is advantageous in terms of manufacturing a high-capacity battery and providing sufficient positive electrode conductivity or adhesion between electrode materials.

[0085] The current collector for the positive electrode is a highly conductive metal, and any metal can be used as long as it can easily adhere to the positive active material slurry and does not react within the voltage range of the electrochemical device. Specifically, non-limiting examples of the positive electrode current collector include foils made of aluminum, nickel, or a combination thereof.

[0086] The positive electrode active material layer further includes a conductive material. The conductive material is usually added based on 1 to 30 weight % of the total weight of the mixture containing the positive electrode active material. The use of such a conductive material is not particularly limited as long as it has high conductivity and does not cause chemical changes in the secondary battery. For example, the conductive material may include one or more selected from the group consisting of graphite, such as natural graphite or artificial graphite; carbon black, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers, such as carbon fibers and metal fibers; metal powders, such as carbon fluoride powders, aluminum powders, and nickel powders; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and derivatives of polyphenylene.

[0087] The negative electrode has a structure in which two negative electrode active material layers are laminated on a negative electrode current collector. In one example, the negative electrode active material layer includes a negative electrode active material, a conductive material and a binder polymer, and if necessary, may further include a negative electrode additive commonly used in the art.

[0088] The negative electrode active material may include a carbon material, lithium metal, silicon, tin, etc. When a carbon material is used as the negative electrode active material, both low crystalline carbon and high crystalline carbon may be used. Typical examples of low crystalline carbon include soft carbon and hard carbon. Typical examples of high crystalline carbon include one or more high temperature sintered carbons selected from the group consisting of natural graphite, artificial graphite, Kishgraphite, pyrolytic carbon, mesophase pitch based carbon fiber, mesophase-carbon microbeads, mesophase pitch, and coke derived from petroleum or coal tar pitch, etc.

[0089] Non-limiting examples of the current collector used in the negative electrode include foils made of copper, gold, nickel or copper alloys or combinations thereof. In addition, the current collector may be used by laminating a substrate made of the above materials.

[0090] In addition, the negative electrode may include a conductive material and a binder commonly used in the art.

[0091] Figure 5 Shown according to Figure 3 The level change in the supply tank of one embodiment (Example 1) is related to the Figure 6 Results of experimental data comparing the level changes in the supply tanks of the prior art.

[0092] exist Figure 5 In the graph of , the orange line is a graph showing the level change of the supply tank 500 according to Example 1 of the present disclosure, and the light blue line is a comparative example, which shows a graph showing the level change of the supply tank 500 according to the prior art.

[0093] In Example 1 and the comparative example, in the case of the positive electrode slurry, the corresponding experiments were conducted when the storage capacity of the delivery tank 400 was about 800 L and the storage capacity of the supply tank 500 was about 120 L.

[0094] As mentioned above Figure 3 As described, Example 1 of the present disclosure corresponds to a case where slurry is supplied from the delivery tank 400 to the supply tank 500 for a predetermined period of 3 seconds, then the supply is interrupted, and this process is repeated. The comparative example corresponds to the case described as the prior art in the background art.

[0095] from Figure 5 It can be seen from the comparison curve graph in that if the stable target level of the supply tank 500 is 41%, in Example 1 of the present disclosure, the level of the supply tank 500 is maintained at a constant level without significant changes within the range of 40% to 41% (i.e., within the range of 1%), thereby stably performing the electrode coating process, while in the comparative example, the level of the supply tank 500 varies to a greater extent within the range of 38% to 54% (i.e., within the range of 16%) than in Example 1. Therefore, the temperature change (disturbance) based on the level of the supply tank 500 is about 0.2°C in the comparative example, but is greatly and stably improved to about 0.01°C in Example 1.

[0096] According to the method for controlling the supply amount of electrode slurry according to an embodiment of the present disclosure, by improving the conventional electrode slurry supply method, when a preset level is reached, the slurry is only supplied for a predetermined time and then interrupted, and then when the preset level is reached again, the process of supplying the slurry only for a predetermined time and then interrupted is repeated, thereby preventing excessive supply of slurry and minimizing the resulting temperature change in the slurry.

[0097] Furthermore, by adjusting the amount of slurry supplied from the delivery tank to the supply tank in real time according to the respective temperatures of the supply tank and the delivery tank, it is possible to minimize temperature variation of the slurry in the supply tank connected to the electrode coater and stabilize the temperature of the slurry.

[0098] Due to the above advantages, the production efficiency of the electrode assembly can be maximized, thereby improving manufacturing efficiency and product quality.

[0099] Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and those skilled in the art may make various modifications and improvements using the basic concepts of the present disclosure as defined in the appended claims, which also fall within the scope of the present disclosure.

[0100] [Explanation of Reference Numbers]

[0101] 100: Mixer

[0102] 200: Storage tank

[0103] 300: Buffer tank

[0104] 400: Conveying tank

[0105] 500: Supply tank

[0106] 600: Coating machine

[0107] 700: current collector layer.

Claims

1. A method for controlling the supply amount of electrode slurry, the method comprising the following steps: supplying slurry from a first tank to a coater; When the storage amount of the slurry in the first tank decreases and the level of the first tank reaches a first predetermined level, supplying the slurry from a second tank connected to the first tank to the first tank for a predetermined time; and After the predetermined time has elapsed, the supply of slurry from the second tank to the first tank is automatically interrupted.

2. The method for controlling the supply amount of electrode slurry according to claim 1, further comprising the following steps: When the level of the first tank reaches the first predetermined level again, the slurry is supplied from the second tank to the first tank again for the predetermined time.

3. The method for controlling the supply amount of electrode slurry according to claim 1, wherein: The first predetermined level is a target level of a storage amount of slurry in the first tank.

4. The method for controlling the supply amount of electrode slurry according to claim 1, further comprising the following steps: during the predetermined time period of slurry being supplied from the second tank to the first tank, when the level of the first tank reaches a second predetermined level, interrupting the supply of slurry from the second tank to the first tank, The second predetermined level is a value higher than the first predetermined level and lower than an upper limit level of the storage amount of the slurry in the first tank.

5. The method for controlling the supply amount of electrode slurry according to claim 1, wherein: The level of the first tank is the height or volume of the first tank.

6. The method for controlling the supply amount of electrode slurry according to claim 1, wherein: The slurry storage capacity of the first tank is smaller than the slurry storage capacity of the second tank.

7. A method for controlling the supply amount of electrode slurry, the method comprising the following steps: Measure the temperature of the first tank; measuring the temperature of the second tank; and The supply amount of the slurry from the second tank to the first tank is controlled according to the temperature of the first tank and the temperature of the second tank.

8. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank corresponds to a predetermined normal temperature range and the temperature of the second tank corresponds to the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is increased.

9. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank corresponds to a predetermined normal temperature range and the temperature of the second tank is higher or lower than the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is maintained.

10. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank is higher or lower than a predetermined normal temperature range and the temperature of the second tank corresponds to the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is increased.

11. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank is higher than a predetermined normal temperature range and the temperature of the second tank is lower than the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is increased.

12. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank is lower than a predetermined normal temperature range and the temperature of the second tank is higher than the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is increased.

13. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank is higher than a predetermined normal temperature range and the temperature of the second tank is higher than the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is maintained.

14. The method for controlling the supply amount of electrode slurry according to claim 7, wherein: The step of controlling the supply amount of the slurry from the second tank to the first tank comprises: When the temperature of the first tank is lower than a predetermined normal temperature range and the temperature of the second tank is lower than the predetermined normal temperature range, the supply amount of the slurry from the second tank to the first tank is maintained.

15. The method for controlling the supply amount of electrode slurry according to any one of claims 8 to 14, wherein: The predetermined normal temperature range is a temperature range preset to be suitable for slurry coating.

16. An electrode slurry supply device for executing the method according to claim 1 or 7, the electrode slurry supply device comprising: a coating machine for applying the slurry; a first tank for supplying slurry to the coater; a second tank storing the slurry and supplying the slurry to the first tank; A pipe connecting the first tank and the second tank; and A valve is disposed in the conduit.

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