Electrode slurry coating system and electrode slurry coating method

Abstract

The electrode slurry coating system according to the present invention includes a supply pipe that serves as a transfer path for electrode slurry from a supply tank to a coating die, a mass flow meter installed on the route of the supply pipe to measure the flow rate and density of the electrode slurry transferred through the supply pipe, and a control unit that calculates a predicted loading amount of electrode slurry based on measurement information measured by the mass flow meter and controls the calculated predicted loading amount of electrode slurry to satisfy a loading amount management range.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0124418, filed on September 19, 2023.

[0002] The present invention relates to an electrode slurry coating system and an electrode slurry coating method. [Background technology]

[0003] As technological development and demand for mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing. In recent years, secondary batteries have been used as power sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs). As a result, there is a high demand for lithium secondary batteries, which have high energy density, high discharge voltage, and output stability.

[0004] In particular, lithium secondary batteries used as power sources for electric vehicles and hybrid electric vehicles are required to have high energy density and the ability to generate large output in a short period of time.

[0005] In general, a lithium secondary battery is manufactured by using a material capable of intercalating and deintercalating lithium ions as the negative and positive electrodes, and filling an organic or polymer electrolyte between the positive and negative electrodes. Electrical energy is generated through oxidation and reduction reactions when lithium ions are intercalated and deintercalated from the positive and negative electrodes.

[0006] In this case, the negative electrode and the positive electrode each include an electrode active material layer on a current collector of the electrode, and such electrodes may be manufactured by mixing and stirring the electrode active material with a binder and a solvent, and optionally a conductive material and a dispersant, to prepare an electrode slurry, and then coating the electrode slurry on a current collector using a slot die coater, followed by drying and rolling.

[0007] In the electrode slurry coating process, it is important to maintain a uniform electrode slurry loading amount for electrode quality control. Conventionally, the electrode slurry loading amount is controlled by measuring the electrode slurry loading amount during the initial condition adjustment step of the coating process, repeatedly adjusting the motor RPM (rotations per minute) several times until the measured electrode slurry loading amount falls within the control range, and then converting the measurement information measured on the dried electrode using a web gauge into the electrode slurry loading amount before drying. However, this method has the problem of significant material loss because changes in the electrode slurry loading amount due to filter clogging or pump malfunctions during the coating process can be confirmed after the electrode drying process. Furthermore, this method makes it impossible to conduct a 100% inspection, which may result in products that do not meet specifications.

[0008] Therefore, there is a need to develop a technology for an electrode slurry coating system and method that can manage the electrode slurry loading amount in real time. Summary of the Invention [Problem to be solved by the invention]

[0009] The problem to be solved by the technical idea of ​​the present invention is to provide an electrode slurry coating system and an electrode slurry coating method that reliably calculate a predicted value of electrode slurry loading amount in real time during a coating process of an electrode slurry, and automatically control the loading amount so that the calculated predicted value falls within a control range. [Means for solving the problem]

[0010] According to one embodiment of the present invention, there is provided an electrode slurry coating system, which includes: a supply pipe that connects a supply tank for storing electrode slurry to a coating die for applying the electrode slurry to an electrode substrate and serves as a transport path for the electrode slurry from the supply tank to the coating die, a mass flow meter installed on the supply pipe for measuring the flow rate and density of the electrode slurry transported through the supply pipe, and a control unit that calculates a predicted electrode slurry loading amount based on measurement information measured by the mass flow meter and controls the calculated predicted electrode slurry loading amount to satisfy a loading amount management range.

[0011] The electrode slurry coating system according to one embodiment further includes a pump configured to provide a driving force for transporting the electrode slurry to the coating die.

[0012] In one embodiment, the control unit includes a calculation unit that calculates a predicted loading amount of the electrode slurry by substituting a flow rate value of the electrode slurry and a density value of the electrode slurry measured by a mass flow meter into the following Equation 1 and / or Equation 2.

[0013] [Formula 1] Estimated loading amount = [Flow rate of electrode slurry × {1 - (density of electrode slurry solvent / density of electrode slurry)}] / A [Formula 2] Predicted loading amount = [Flow rate of electrode slurry × {Solid concentration of electrode slurry / (Coating width length of electrode slurry × Coating speed of electrode slurry)}] + B The electrode slurry coating system according to one embodiment may further include a loading amount measuring device for measuring the loading amount of electrode slurry to be coated on the electrode, and the calculation unit may be configured to calculate the correction constant A of Equation 1 from the measured value of the electrode slurry loading amount measured by the loading amount measuring device and the predicted value of the electrode slurry loading amount calculated by substituting it into Equation 1 when the correction constant A is not determined.

[0014] In one embodiment, the control unit controls to adjust the RPM of the pump until the calculated predicted value of the electrode slurry loading amount satisfies the loading amount management range.

[0015] In one embodiment, the control unit controls the electrode coating process to start or continue when the calculated predicted value of the electrode slurry loading amount satisfies the loading amount management range.

[0016] The control unit controls the device to generate an alarm sound when the calculated predicted value of the electrode slurry loading amount does not satisfy the loading amount management range.

[0017] The electrode slurry coating system according to one embodiment further includes an HMI (Human-machine interface) for communication with the control unit.

[0018] According to another embodiment of the present invention, there is provided a method for coating an electrode slurry, the method including: (a) setting coating process conditions using an electrode model; (b) setting a pump RPM; (c) test-coating an electrode substrate with an electrode slurry according to the set coating process conditions; (d) determining whether a predicted electrode slurry loading amount satisfies a control range for the electrode slurry loading amount; and (e) starting the coating process to coat the electrode slurry if it is determined that the predicted electrode slurry loading amount satisfies the control range in the determining step. The step of test-coating the electrode slurry (c) includes: (c-1) measuring a flow rate and a density of the electrode slurry; and (c-2) calculating a predicted electrode slurry loading amount based on the measurement information.

[0019] In one embodiment, in the step (c-1) of measuring the flow rate and density of the electrode slurry, the flow rate and density of the electrode slurry are measured by a mass flow meter installed on the route of the supply piping.

[0020] In one embodiment, in the step (c-2) of calculating the predicted loading amount of the electrode slurry, the flow rate value of the electrode slurry and the density value of the electrode slurry are substituted into the following formula 1 and / or formula 2 to calculate the predicted loading amount of the electrode slurry.

[0021] [Formula 1] Estimated loading amount = [Flow rate of electrode slurry × {1 - (density of electrode slurry solvent / density of electrode slurry)}] / A [Formula 2] Predicted loading amount = [Flow rate of electrode slurry × {Solid concentration of electrode slurry / (Coating width length of electrode slurry × Coating speed of electrode slurry)}] + B In one embodiment, if it is determined in the determining step (d) that the condition is not satisfied, steps (b) through (d) are repeated until it is determined in the determining step (d) that the condition is satisfied.

[0022] In one embodiment, (b) setting the RPM of the pump comprises: When the correction constant A of Equation 1 is determined, the RPM of the pump is set so that the predicted value of the electrode slurry loading amount in Equation 1 satisfies the target value of the electrode slurry loading amount; When the correction constant A in Equation 1 is not determined, the method includes a step of setting the RPM of the pump so that the predicted value of the electrode slurry loading amount calculated according to Equation 2 satisfies the target value of the electrode slurry loading amount.

[0023] The electrode slurry coating method according to one embodiment further includes (f) a loading amount measuring step of measuring a loading amount of the electrode slurry applied onto the electrode substrate.

[0024] According to one embodiment, the electrode slurry coating method further includes, when the correction constant A of Equation 1 is not determined, calculating the correction constant A of Equation 1 so that the predicted electrode slurry loading amount calculated by substituting the correction constant A into Equation 1 is the same as the measured electrode slurry loading amount.

[0025] In one embodiment, when the correction constant A of Equation 1 is determined, the electrode slurry coating method further includes a step of recalculating the correction constant A of Equation 1 if the difference between the predicted electrode slurry loading amount calculated according to Equation 1 and the measured electrode slurry loading amount measured in the (f) loading amount measurement step exceeds a reference range.

[0026] In one embodiment, the (e) coating step comprises: (e-1) measuring the flow rate of the electrode slurry and the density of the electrode slurry; (e-2) calculating a predicted value of the electrode slurry loading amount based on the measurement information; (e-3) a determination step of determining whether the predicted value of the electrode slurry loading amount satisfies the electrode slurry loading amount management range; (e-4) When it is determined in the determining step that the condition is not met, the step of readjusting the RPM of the pump is included.

[0027] In one embodiment, the coating process conditions include one or more of a target loading amount of the electrode slurry, a coating speed of the electrode slurry, a coating width length, and a solids concentration of the electrode slurry. [Effects of the Invention]

[0028] The electrode slurry coating system and coating method according to the present invention manage the electrode slurry loading amount based on information measured in the electrode slurry state, rather than on the loading amount measured after the electrode is dried. This minimizes waste of electrode material compared to conventional techniques that determine whether or not there is a loading defect after drying.

[0029] The electrode slurry coating system and coating method according to the present invention manage the electrode slurry loading amount not based on the measured value of the electrode slurry loading amount, but by calculating a predicted value of the electrode slurry loading amount from the flow rate and density of the electrode slurry, which are easy to measure, thereby improving the convenience of loading amount management.

[0030] The electrode slurry coating system and coating method according to the present invention can improve reliability by calculating the predicted value of the electrode slurry loading amount based not on the solids concentration of the electrode slurry, but on the flow rate and density of the electrode slurry.

[0031] The electrode slurry coating system and coating method according to the present invention include a control unit that controls the RPM of the pump so that the predicted value of the electrode slurry loading amount calculated based on measurement information measured in real time falls within the electrode slurry loading amount management range, thereby reducing the incidence of loading failures. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a block diagram of an electrode slurry coating system according to an exemplary embodiment of the present invention. [Figure 2] 1 is a schematic diagram of an electrode slurry coating system according to a first embodiment. FIG. [Figure 3] FIG. 10 is a schematic diagram of an electrode slurry coating system according to a second embodiment. [Figure 4] 1 is a flow chart illustrating an electrode slurry coating method according to an exemplary embodiment of the present invention. [Figure 5] 1 is a flowchart illustrating a test coating step according to an exemplary embodiment of the present invention. [Figure 6] 1 is a flow chart illustrating an electrode slurry coating method according to an exemplary embodiment of the present invention. [Figure 7] 1 is a diagram showing an HMI of an electrode slurry coating system according to a first embodiment. [Figure 8] 10 is a diagram showing an HMI of an electrode slurry coating system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. As a premise, the terms and words used in the specification and claims should not be interpreted as being limited to their general or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to best describe his / her own invention.

[0034] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0035] Furthermore, in the description of the present invention, if it is determined that a specific description of related publicly known configurations or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0036] Since the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown schematically for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0037] In this specification, the term "loading amount of electrode slurry" is a concept that includes both the weight of the electrode slurry coated on the current collector, which is the substrate of the electrode, and the weight of the electrode slurry per unit area.

[0038] <Electrode Slurry Coating System> The present invention provides, as a first embodiment, an electrode slurry coating system.

[0039] (First embodiment) FIG. 1 is a block diagram of an electrode slurry coating system according to an exemplary embodiment of the present invention, and FIG. 2 is a schematic diagram of an electrode slurry coating system according to a first embodiment.

[0040] Referring to these drawings, an electrode slurry coating system 100 according to an exemplary embodiment of the present invention may include a supply tank 110, a coating die 120, supply piping 130, a pump 140, a mass flow meter 150, a control unit 160, an HMI 170, and valves 181, 182.

[0041] According to an exemplary embodiment of the present invention, a mass flow meter 150 is installed on the path of the supply pipe 130, and the flow rate and density of the electrode slurry transferred from the supply pipe 130 are measured by the mass flow meter 150. The control unit 160 calculates a predicted electrode slurry loading amount based on the measurement information and controls the calculated predicted electrode slurry loading amount to satisfy a preset loading amount management range. Therefore, since the electrode slurry loading amount is managed in real time based on the predicted electrode slurry loading amount during the electrode slurry coating process, it is possible to reduce material loss and the incidence of electrodes that do not comply with loading amount management specifications, compared to conventional techniques in which changes in the electrode slurry loading amount can be confirmed after the electrode drying process.

[0042] The electrode slurry coating system of the present invention will be described in detail below.

[0043] The supply tank 110 may have an internal space in which an electrode slurry containing an electrode active material can be accommodated for storing the electrode slurry. The supply tank 110 may be configured to supply the electrode slurry to the coating die 120 via an appropriate means. In some embodiments, an agitator for uniformly mixing the electrode slurry may be provided in the supply tank 110, and the electrode slurry coating system 100 may further include a drive device capable of driving the agitator.

[0044] The electrode slurry may be a positive electrode slurry containing a positive electrode active material, or may be a negative electrode slurry containing a negative electrode active material.

[0045] The coating die 120 may be configured to coat the electrode slurry transferred from the supply tank 110 onto the electrode substrate. The coating die 120 may be configured to apply the electrode slurry to the electrode substrate with an appropriate width and thickness. The coating die 120 may have a slot that can discharge the electrode slurry with a predetermined width and thickness, and may have an internal structure that allows the electrode slurry to be discharged at a constant pressure overall.

[0046] The supply pipe 130 connects the supply tank 110 and the coating die 120 and serves as a path for transferring the electrode slurry from the supply tank 110 to the coating die 120 .

[0047] A pump 140 may be provided on the supply pipe 130. Here, when a specific element is provided "on" a pipe, it means that the specific element is interposed in the middle of the pipe or that the specific element is connected to the end of the pipe, and the same applies hereinafter unless otherwise specified.

[0048] The pump 140 may be configured to provide a driving force for transferring the electrode slurry to the coating die 120. The pump 140 applies a predetermined range of pressure to the electrode slurry stored in the supply tank 110, thereby providing a driving force for transferring the electrode slurry through the supply pipe 130 to the coating die 120. In some embodiments, the pump 140 may be a pump that forcibly pumps the electrode slurry. In some embodiments, the pump 140 may be a pump that applies centrifugal force to the electrode slurry to transfer it. However, the present invention is not limited thereto.

[0049] One or more filters F may be provided on the path of the supply pipe 130. In some embodiments, a magnetic first filter may be provided on the supply pipe 130. The first filter may be provided to remove specific magnetic impurities in the electrode slurry.

[0050] In some embodiments, a second filter may be provided on the supply pipe 130. The second filter may include a filter membrane for filtering out foreign matter in the electrode slurry.

[0051] A return pipe 190 may be provided on the path of the supply pipe 130. The return pipe 190 is configured to branch off from the supply pipe 130 and return to the supply tank 110 in order to recover a portion of the electrode slurry to the supply tank 110 when a line stop occurs. In some embodiments, the return pipe 190 may branch off from the supply pipe 130 by a tee pipe.

[0052] One or more valves 181, 182 for controlling the flow path of the electrode slurry may be included on the supply pipe 130. Specifically, the valves may include a supply valve 181 for controlling the transfer of the electrode slurry to the coating die 120 and a return valve 182 for controlling the return of the electrode slurry to the supply tank 110.

[0053] In some embodiments, supply valve 181 and return valve 182 may each be an on-off valve configured to be opened and closed by an electrical signal, hydraulic pressure, or pneumatic pressure, or may each be a control valve whose degree of opening can be precisely controlled by an electrical signal, hydraulic pressure, or pneumatic pressure.

[0054] The supply valve 181 may be provided between the coating die 120 and the branch point where the return pipe 190 branches off from the supply pipe 130. The return valve 182 may be provided between the supply tank 110 and the branch point where the return pipe 190 branches off from the supply pipe 130.

[0055] The flow path and / or flow rate of the electrode slurry can be controlled by adjusting the opening and closing of the supply valve 181 and the return valve 182. In some embodiments, when the supply valve 181 is opened while the return valve 182 is closed, the electrode slurry may not be collected in the supply tank 110 and may be supplied in its entirety to the coating die 120. In other embodiments, when the supply valve 181 is closed while the return valve 182 is opened, the electrode slurry may not be collected in its entirety to the coating die 120 and may be supplied in its entirety to the supply tank 110.

[0056] One or more pressure gauges may be provided on the supply pipe 130. The pressure gauges may be provided at any positions on the supply pipe 130 where pressure measurement is required. The pressure gauges may be configured to generate an electrical signal in response to the transport pressure of the electrode slurry, or may be configured to generate a pneumatic signal.

[0057] In some embodiments, a pressure gauge may be provided between pump 140 and coating die 120. In some embodiments, a pressure gauge may be provided between pump 140 and mass flow meter 150. In some embodiments, a pressure gauge may be provided between the first filter and the second filter, and between the second filter and mass flow meter 150, respectively.

[0058] Mass flow meter 150 may be installed on the path of supply piping 130 and configured to measure the flow rate and density of the electrode slurry transported through the supply piping. In some embodiments, mass flow meter 150 may be configured to measure the flow rate of the electrode slurry flowing per unit time and calculate the density of the electrode slurry therefrom. In some embodiments, mass flow meter 150 may include a temperature sensor to correct for the effect of temperature, taking into account that the measured values ​​of the flow rate and density of the electrode slurry are affected by temperature. In some embodiments, mass flow meter 150 may be a Coriolis mass flow meter configured to directly measure the flow rate, density, and temperature of the electrode slurry.

[0059] The control unit 160 calculates a predicted value of the electrode slurry loading amount based on the measurement information measured by the mass flow meter 150, and controls the calculated predicted value of the electrode slurry loading amount to satisfy the loading amount management range.

[0060] In some embodiments, the control unit 160 may include a calculation unit for calculating a predicted loading amount of the electrode slurry, and the calculation unit may calculate the predicted loading amount of the electrode slurry by substituting the flow rate value of the electrode slurry measured by the mass flow meter and the density value of the electrode slurry into the following Equation 1 and / or Equation 2.

[0061] [Formula 1] Estimated loading amount = [Flow rate of electrode slurry × {1 - (density of electrode slurry solvent / density of electrode slurry)}] / A [Formula 2] Predicted loading amount = [Flow rate of electrode slurry × {Solid concentration of electrode slurry / (Coating width length of electrode slurry × Coating speed of electrode slurry)}] + B Here, correction constants A and B are correction constants that reflect errors in the measurement values ​​and errors caused by the coating equipment, respectively. The predicted loading amount calculated according to Equation 1 or Equation 2 is based on one or more of the measured values ​​of flow rate, density, and solid concentration, but these measured values ​​may vary depending on the measurement environment and measurement conditions. Furthermore, even if the measured values ​​are the same, the predicted value may vary depending on the coating equipment. Correction constants A and B can reflect such measurement errors and coating equipment errors, thereby improving the accuracy of the predicted loading amount.

[0062] Such correction constants A and B can be calculated from the measured value of the loading amount and the predicted value of the loading amount, and after the correction constants A and B are determined, the loading amount can be predicted according to Equation 1 and / or Equation 2 without measuring the loading amount.

[0063] The electrode slurry coating system 100 according to the present invention can manage the electrode slurry loading amount based on the predicted electrode slurry loading amount calculated according to Equation 1 and / or Equation 2, which is advantageous in that it is not necessary to measure the electrode slurry loading amount in the electrode slurry state. Furthermore, it is possible to correct errors caused by the coating equipment using the correction constant A and / or correction constant B, thereby improving the reliability.

[0064] When the correction constant A is known or determined, the predicted loading amount of the electrode slurry may be calculated according to Equation 1. In Equation 1, the flow rate and density of the electrode slurry are substituted with values ​​measured by mass flow meter 150. Furthermore, in Equation 1, the density of the solvent of the electrode slurry is substituted with the density value of the solvent, such as NMP (N-methylpyrrolidone) or water. In Equation 1, A is a correction constant used to correct errors caused by the coating equipment.

[0065] When the correction constant A is unknown or cannot be determined, the predicted electrode slurry loading amount may be calculated according to Equation 2. In Equation 2, the solids concentration of the electrode slurry, the coating width length of the electrode slurry, and the coating speed of the electrode slurry are substituted with values ​​preset for each electrode model. Furthermore, the flow rate of the electrode slurry in Equation 2 is substituted with a value measured by a mass flow meter. Furthermore, in Equation 2, B is a correction constant used to correct for errors caused by the coating equipment.

[0066] The solids concentration of the electrode slurry in Formula 2 varies with the aging of the electrode slurry, resulting in an error in the measured value of the solids concentration. That is, the predicted value of the electrode slurry loading amount according to Formula 2 may have an error due to an error in the actual measurement of the solids concentration of the electrode slurry. Therefore, Formula 1 can be more reliable than Formula 2 in predicting the electrode slurry loading amount.

[0067] Therefore, the electrode slurry coating system 100 according to the present invention basically calculates the predicted electrode slurry loading amount according to Equation 1, but only when the correction constant A in Equation 1 is unknown or cannot be determined, the predicted electrode slurry loading amount can be calculated auxiliary according to Equation 2.

[0068] The electrode slurry coating system 100 may further include a loading amount meter (not shown) to derive the correction constant A when the predicted electrode slurry loading amount cannot be calculated according to Equation 1. Even if the predicted electrode slurry loading amount can be calculated according to Equation 1, a loading amount meter may be needed to recalculate the correction constant A due to measurement tolerances of the mass flow meter that occur with time during the coating step.

[0069] In some embodiments, the control unit 160 may perform control to perform a test coating process before starting the actual coating process of the electrode, and derive the correction constant A in the test coating process.

[0070] The type of the loading amount measuring device is not limited as long as it is a means capable of measuring the loading amount of the electrode slurry applied to the electrode substrate. In some embodiments, the loading amount measuring device may be a web gauge.

[0071] Theoretically, the predicted value of the electrode slurry loading amount should match the measured value of the electrode slurry loading amount, so the correction constant A in Equation 1 or the correction constant B in Equation 2 can be calculated from the measured value of the electrode slurry loading amount measured by a loading amount measuring device and the predicted value of the electrode slurry loading amount calculated by substituting it into Equation 1 or Equation 2.

[0072] The control unit 160 may control the pump to adjust the RPM until the predicted loading amount of the electrode slurry calculated according to Equation 1 and / or Equation 2 satisfies the loading amount management range. Specifically, when the predicted loading amount value is smaller than the loading amount management range, the control unit 160 may control the pump to increase the RPM to increase the loading amount, and conversely, when the predicted loading amount value is larger than the loading amount management range, the control unit 160 may control the pump to decrease the RPM to decrease the loading amount.

[0073] In some embodiments, the control unit 160 may perform control to start the electrode coating process when the predicted loading amount of the electrode slurry calculated as described above satisfies the loading amount management range.

[0074] In some embodiments, even after the electrode coating process has started, the control unit 160 calculates a predicted value of the electrode slurry loading amount based on the electrode slurry flow rate and electrode slurry density measured in real time, determines whether the calculated predicted value of the electrode slurry loading amount satisfies the electrode slurry loading amount control range, and controls the RPM of the pump if the control range is not satisfied.

[0075] In some embodiments, the control unit 160 can perform control so as to generate an alarm sound when the predicted value of the electrode slurry loading amount calculated as described above does not satisfy the loading amount management range.

[0076] By way of non-limiting example, control unit 160 may be a PLC (Programmable Logic Controller). A PLC is a specialized form of microprocessor-based controller that uses programmable memory to store instructions and perform functions such as logic, sequencing, timing, counting, and arithmetic to control machines and processes. PLCs are easy to operate and program.

[0077] In some embodiments, the control unit 160 may include a central processing unit (CPU), an input interface, an output interface, a communication interface, and a memory device.

[0078] The memory device may include ROM (Read Only Memory), which is configured to store system programs such as an operating system, and RAM (Random Access Memory), which is configured to store user programs and data such as input / output device status information, timer, counter and other internal device values.

[0079] The CPU may be configured to implement logic and control communication between modules that convert input signals into output operating signals. The CPU can operate based on system programs and user programs stored in the memory device. The CPU may be configured to write measurement data to or read measurement data from a data area of ​​the memory device based on the system programs and user programs.

[0080] Coating process conditions and data for each electrode model may be transmitted to the CPU via the input interface, and the results processed by the CPU may be output via the output interface.

[0081] In some embodiments, the electrode slurry coating system 100 may further include an HMI for communication with the control unit 160. An operator may input an electrode model to be coated via the HMI, and the control unit may output, via the HMI, preset electrode coating process conditions (target loading amount, coating speed, coating width and length, solid content concentration) for the input electrode model, the electrode slurry flow rate value and electrode slurry density value measured in real time, a predicted electrode slurry loading amount value, a measured electrode slurry temperature value, and determination information for determining whether the predicted electrode slurry loading amount value matches a loading amount control range.

[0082] FIG. 7 is a diagram showing the HMI of the electrode slurry coating system according to the first embodiment.

[0083] Referring to FIG. 7 , touching the “SET” tab (1) moves to an HMI where coating process condition data is output. Touching the “LOAD” tab (2) allows the user to call up and input coating process condition data. The coating process conditions selected in this manner (model name, target value of loading amount, coating speed, coating width length, and solids concentration of electrode slurry) may be output via the HMI (3). The flow rate, density, and temperature measurements of the electrode slurry measured by the mass flow meter 150 may be output via the HMI (4), and a predicted value of the electrode slurry loading amount calculated based on the measurement information of the mass flow meter may be output via the HMI (5).

[0084] The predicted electrode slurry loading amount is compared with the electrode slurry loading amount control range, and an alarm can be set as shown in FIG. 6 to warn of a situation where the predicted electrode slurry loading amount falls outside the loading amount control range. In an exemplary embodiment, the loading amount control range may be classified into a primary control range, which is a preferable control range, and a secondary control range, which is a standard for determining whether a product is good or bad. If the predicted loading amount falls within the primary control range, the predicted loading amount can be output in green. If the predicted loading amount falls outside the primary control range but not the secondary control range, the predicted loading amount can be output in yellow. If the predicted loading amount falls outside the secondary control range, the predicted loading amount can be output in red.

[0085] If the electrode slurry coating system 100 includes a loading amount measuring instrument (not shown), the measured value from the loading amount measuring instrument can be input by touching the tab 7.

[0086] Then, when the correction constant A of Equation 1 has been determined and the predicted electrode slurry loading amount is calculated according to Equation 1, the "Offset" of 8 may be output as "Active" in the sense that the correction constant A has been determined. However, when the correction constant A of Equation 1 has not been determined and the predicted electrode slurry loading amount cannot be calculated according to Equation 1, and the predicted electrode slurry loading amount is calculated according to Equation 2, the "Offset" of 8 may be output as "Inactive."

[0087] (Second embodiment) Fig. 3 is a schematic diagram of an electrode slurry coating system according to a second embodiment. Referring to Fig. 3, the electrode slurry coating system 200 according to the second embodiment has two or more slots through which the electrode slurry is discharged from the coating die 120, and therefore can be an electrode slurry coating system for manufacturing electrodes with multiple layers.

[0088] As a non-limiting example, the coating die 120 may be configured to have two or more slots, and may be configured so that one slot ejects the first electrode slurry and the other slot ejects the second electrode slurry. In this case, the first electrode slurry and the second electrode slurry may have the same composition or different compositions.

[0089] The electrode slurry coating system 200 includes a first supply tank 110 for storing the first electrode slurry and a second supply tank 210 for storing the second electrode slurry for coating the first electrode slurry and the second electrode slurry, a coating die 120 for applying the first electrode slurry and the second electrode slurry onto an electrode substrate, a first supply pipe 130 that serves as a transport path for the first electrode slurry from the first supply tank 110 to the coating die 120 and a second supply pipe 230 that serves as a transport path for the second electrode slurry from the second supply tank 210 to the coating die 120, a first pump 140 configured to provide a driving force for transporting the first electrode slurry to the coating die 120, and a second pump 250 configured to transport the second electrode slurry to the coating die 120. The electrode slurry supply system may include a second pump 240 configured to provide a driving force for the first electrode slurry, a first mass flow meter 150 installed on the path of the first supply pipe 130 to measure the flow rate and density of the first electrode slurry transferred through the first supply pipe 130, and a second mass flow meter 250 installed on the path of the second supply pipe 230 to measure the flow rate and density of the second electrode slurry transferred through the second supply pipe 230, and a control unit 160 that calculates predicted loading amounts of the first electrode slurry and the second electrode slurry based on the measurement information measured by the first mass flow meter 150 and the second mass flow meter 250, and controls the calculated predicted loading amounts of the electrode slurry to satisfy a loading amount management range.

[0090] The first supply pipe 130 and the second supply pipe 230 may include one or more valves 180, 280 to control the flow paths of the first electrode slurry and the second electrode slurry.

[0091] Furthermore, a first return pipe 190 and a second return pipe 290 may be provided on the paths of the first supply pipe 130 and the second supply pipe 230, respectively.

[0092] The electrode slurry coating system 200 according to the second embodiment differs from the electrode slurry coating system 100 according to the first embodiment only in that it further includes a second supply tank 210 for supplying and transferring the second electrode slurry, a second supply pipe 230, a second pump 240, a second valve 280, a second mass flow meter 250 for measuring the flow rate and density of the second electrode slurry, and a second return pipe 290 for recovering the second electrode slurry. These components have already been described in detail, so a duplicated description will be omitted.

[0093] Fig. 8 is a diagram showing an HMI of an electrode slurry coating system according to a second embodiment. Referring to Fig. 8, the HMI of the electrode slurry coating system according to the second embodiment differs from the electrode slurry coating system according to the first embodiment only in that the HMI is configured to output information on the upper and lower layers of the electrode slurry, respectively.

[0094] Specifically, the coating process conditions (model name, target value of loading amount, coating speed, coating width and length, and solids concentration of electrode slurry) may be output for each of the upper and lower layers via the HMI as shown in 3, the measurement information for each of the upper and lower layers measured by the mass flow meters 150 and 250 (flow rate of electrode slurry, density of electrode slurry, and temperature of electrode slurry) may be output for each of the upper and lower layers via the HMI as shown in 4, and a predicted electrode slurry loading amount value calculated based on the measurement information of the mass flow meters may be output for each of the upper and lower layers via the HMI as shown in 5. Then, the predicted electrode slurry loading amount value and the electrode slurry loading amount control range are compared, and if the predicted electrode slurry loading amount value falls outside the loading amount control range, a warning may be output for each of the upper and lower layers as shown in 6.

[0095] <Electrode slurry coating method> The present invention provides a method for slurry coating an electrode as a second embodiment.

[0096] FIG. 4 is a flowchart illustrating an electrode slurry coating method according to an exemplary embodiment of the present invention, and FIG. 5 is a flowchart illustrating a test coating step according to an exemplary embodiment of the present invention.

[0097] 4, an electrode slurry coating method according to one embodiment of the present invention may include (a) step P110 of setting coating process conditions based on an electrode model, (b) step P120 of setting the pump RPM, (c) step P130 of test coating, (d) step P140 of determining whether the predicted electrode slurry loading amount satisfies the electrode slurry loading amount control range, and (e) step P150 of coating. Also, referring to FIG. 5, (c) step P131 of test coating the electrode slurry may include (c-1) step P131 of measuring the flow rate and density of the electrode slurry, and (c-2) step P132 of calculating the predicted electrode slurry loading amount based on the measurement information.

[0098] According to an electrode slurry coating method according to one embodiment of the present invention, a predicted electrode slurry loading amount is calculated based on the electrode slurry flow rate and electrode slurry density measured in the test coating step P130, and the coating step P150 is initiated only when the calculated predicted electrode slurry loading amount falls within a loading amount control range, thereby minimizing material loss compared to the prior art. Furthermore, during the coating step P150, the electrode slurry loading amount can be controlled in real time through highly accurate measurements of the electrode slurry flow rate and electrode slurry density, thereby improving the reliability and convenience of loading control.

[0099] An electrode slurry coating method according to some embodiments may involve coating an electrode slurry using the electrode slurry coating system 100 described above.

[0100] In some embodiments, (a) Step P110 of setting coating process conditions according to an electrode model may include inputting a model of the electrode to be coated and retrieving coating process conditions preset for the electrode model. In some embodiments, the coating process conditions may be any one or more of a target loading amount, a coating speed (m / s) of the electrode slurry, a coating width length, and a solids concentration of the electrode slurry.

[0101] In some embodiments, (b) Step P120 of setting the pump RPM may be a step of temporarily setting the pump RPM in a state in which the electrode slurry is circulating before the start of the test coating and / or coating process. Here, the state in which the electrode slurry is circulating may be a state in which the electrode slurry is transferred from the supply tank to the coating die via the supply piping and before the electrode slurry is discharged from the coating die. Alternatively, it may be a state in which the electrode slurry is transferred from the supply tank to the coating die via the supply piping and then collected back into the supply tank via the return piping.

[0102] In some embodiments, (b) step P120 of setting the pump RPM may be a step of setting the pump RPM so that the predicted electrode slurry loading amount is equal to the target loading amount set in step (a). Here, the target loading amount may be the set loading amount of the electrode model, and is a concept that is distinct from the loading amount control range. If the former is a specified value, the latter may be a range of loading amount values ​​that serves as a criterion for determining whether a product is good or bad.

[0103] In some embodiments, when an electrode model is input via an HMI, the control unit 160 can output, via the HMI, coating process conditions including a target loading amount value of the electrode model input via the HMI. In addition, the control unit 160 can calculate a predicted loading amount value according to the following Equation 1 and / or Equation 2, automatically calculate a pump RPM so that the calculated predicted loading amount value becomes the target loading amount value, and output the automatically calculated pump RPM via the HMI.

[0104] [Formula 1] Estimated loading amount = [Flow rate of electrode slurry × {1 - (density of electrode slurry solvent / density of electrode slurry)}] / A [Formula 2] Predicted loading amount = [Flow rate of electrode slurry × {Solid concentration of electrode slurry / (Coating width length of electrode slurry × Coating speed of electrode slurry)}] + B When the correction constant A is determined, the predicted loading amount can be calculated according to Equation 1, and when the correction constant A is not determined, the predicted loading amount can be calculated according to Equation 2.

[0105] (c) Step P130 of test coating the electrode slurry is a step for readjusting the motor RPM and fine-tuning the coating width and length of the electrode slurry to meet the target value of the electrode slurry loading amount while coating the electrode slurry according to the set coating process conditions in an environment where the electrode slurry is actually coated, rather than in the slurry circulation state before coating.

[0106] (c) Step P130 of test coating the electrode slurry may include (c-1) step P131 of measuring the flow rate and density of the electrode slurry, and (c-2) step P132 of calculating the predicted electrode slurry loading amount based on the measurement information, in order to readjust the motor RPM so that the predicted electrode slurry loading amount satisfies the target electrode slurry loading amount. Because the predicted electrode slurry loading amount may change slightly when the step is changed from the slurry circulation state before coating to the coating process state, (c) step P130 of test coating the electrode slurry measures the flow rate and density of the electrode slurry in real time, and calculates the predicted electrode slurry loading amount based on the measured values ​​of the electrode slurry flow rate and density.

[0107] (c-1) The step of measuring the flow rate and density of the electrode slurry may be a step of measuring the flow rate and density of the electrode slurry by a mass flow meter 150 installed on the route of the supply piping 130. The mass flow meter 150 has already been described in detail, so a duplicated description will be omitted.

[0108] (c-2) The step of calculating the predicted value of the electrode slurry loading amount may be a step of calculating the predicted value of the electrode slurry loading amount by substituting the flow rate value of the electrode slurry and the density value of the electrode slurry into Equation 1 and / or Equation 2.

[0109] When the correction constant A is determined, the predicted loading amount can be calculated according to Equation 1, and when the correction constant A is not determined, the predicted loading amount can be calculated according to Equation 2.

[0110] In some embodiments, when calculating the loading amount of the electrode slurry according to Equation 1, the flow rate value of the electrode slurry and the density value of the electrode slurry substituted into Equation 1 may be the average value of the flow rate of the electrode slurry and the average value of the density of the electrode slurry measured 6 to 10 seconds before completing the test coating step (c).

[0111] (c) Step P130 of test coating the electrode slurry is ended by closing the supply pipe 130 by operating the valve 181, and then the decision step (d) is carried out.

[0112] (d) The determination step is a step of determining whether or not the predicted value of the electrode slurry loading amount satisfies the electrode slurry loading amount management range.

[0113] If it is determined in (d) decision step P140 that the condition is met, then (e) coating step P150 can be initiated. However, if it is determined in (d) decision step P140 that the condition is not met, then (b) pump RPM setting step P120 through (d) decision step P140 are repeated until it is determined in (d) decision step P140 that the condition is met. Then, only when it is determined in (d) decision step P140 that the condition is met is (e) coating step P150 initiated.

[0114] (e) The coating step P150 may include (e-1) step P151 of measuring the flow rate and density of the electrode slurry, (e-2) step P152 of calculating a predicted value of the electrode slurry loading amount based on the measurement information, (e-3) step P153 of determining whether the predicted value of the electrode slurry loading amount satisfies the electrode slurry loading amount management range, and (e-4) step P154 of readjusting the pump RPM if it is determined not to satisfy the range in the determination step. This allows the electrode slurry loading amount to be appropriately managed in real time during the coating step.

[0115] Hereinafter, the electrode slurry coating method according to the present invention will be described in detail with reference to FIG. 4 when the correction constant A is determined.

[0116] When the correction constant A is determined, the predicted electrode slurry loading amount is calculated according to Equation 1. Specifically, in (b) Step P120 of setting the pump RPM, the pump RPM can be temporarily set so that the predicted electrode slurry loading amount calculated according to Equation 1 satisfies the target loading amount. In (c) Step P130 of test coating, the predicted electrode slurry loading amount can also be calculated according to Equation 1. Then, if it is determined in (d) determination step that the target loading amount is not satisfied, the process returns to (b) Step P120 of setting the pump RPM, and the pump RPM can be readjusted so that the predicted electrode slurry loading amount calculated according to Equation 1 satisfies the target loading amount.

[0117] In some embodiments, the electrode slurry coating method may further include (f) a step of measuring a loading amount of the electrode slurry to be applied to the electrode substrate. Ideally, the predicted loading amount of the electrode slurry is the same as the measured loading amount of the electrode slurry. As described below, in the step of initially determining the correction constant A of Equation 1, the correction constant A is determined so that the predicted loading amount according to Equation 1 and the measured loading amount are the same. However, due to reasons such as measurement tolerance of the mass flow meter as the coating step progresses, the difference between the predicted loading amount according to Equation 1 and the measured loading amount may gradually increase. Therefore, it is preferable to include a step of recalculating the correction constant A of Equation 1 when the difference between the predicted loading amount of the electrode slurry calculated according to Equation 1 and the measured loading amount of the electrode slurry measured in the (f) loading amount measuring step exceeds a reference range.

[0118] In some embodiments, the (f) loading amount measurement step may be performed after the (c) test coating step P130, or in some embodiments, the (f) loading amount measurement step may be performed during the (e) coating step.

[0119] Hereinafter, the electrode slurry coating method according to the present invention when the correction constant A is not determined will be described in detail with reference to FIG.

[0120] If the correction constant A is not determined, the predicted electrode slurry loading amount cannot be immediately calculated according to Equation 1, and therefore (b) the step of setting the pump RPM may include a step of setting the pump RPM so that the predicted electrode slurry loading amount calculated according to Equation 2 satisfies the target electrode slurry loading amount. The method may further include a step P160 of measuring the electrode slurry loading amount to calculate the correction constant A of Equation 1, and a step P170 of calculating the correction constant A of Equation 1 so that the predicted electrode slurry loading amount calculated by substituting it into Equation 1 is the same as the measured electrode slurry loading amount.

[0121] Once the correction constant A is derived in this way, it becomes possible to calculate the predicted electrode slurry loading amount according to Equation 1.

[0122] Steps P110 to P160, excluding step P170 for calculating the correction constant A in equation 1, have already been described in detail, so a duplicated description will be omitted.

[0123] The electrode slurry coating system 100, 200 and the electrode slurry coating method according to the present invention can manage the electrode slurry loading amount by measuring the electrode slurry flow rate and electrode slurry density with high measurement accuracy, thereby improving the reliability and convenience of loading amount management.

[0124] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0125] 100, 200: Electrode slurry coating system 110: Supply tank, first supply tank 210: Second supply tank 120: Coating die 130: Supply pipe, first supply pipe 230:Second supply piping 140: Pump, first pump 240: Second pump 150: Mass flow meter, 1st mass flow meter 250:Second mass flow meter 160: Control unit 170:HMI 180: Valve, first valve 280: Second valve 182: Return valve 190: Return pipe, first return pipe

Claims

1. 1. An electrode slurry coating system for coating an electrode slurry onto an electrode substrate, comprising: a supply pipe that connects a supply tank for storing the electrode slurry with a coating die for applying the electrode slurry onto the electrode substrate, and serves as a transfer path for the electrode slurry from the supply tank to the coating die; a mass flow meter installed on the path of the supply piping to measure the flow rate and density of the electrode slurry transported through the supply piping; a control unit that calculates a predicted value of the electrode slurry loading amount based on measurement information measured by the mass flow meter, and controls the calculated predicted value of the electrode slurry loading amount to satisfy a loading amount management range.

2. The electrode slurry coating system of claim 1 , further comprising a pump configured to provide a driving force for transporting electrode slurry to the coating die.

3. The control unit includes a calculation unit that calculates a predicted value of the electrode slurry loading amount by substituting a flow rate value of the electrode slurry and a density value of the electrode slurry measured by the mass flow meter into the following Formula 1 and / or Formula 2: [Formula 1] Predicted loading amount = [Flow rate of electrode slurry × {1 - (density of solvent in electrode slurry / density of electrode slurry)}] / A [Formula 2] Predicted loading amount = [Flow rate of electrode slurry × {Solid concentration of electrode slurry / (Coating width length of electrode slurry × Coating speed of electrode slurry)}] + B 3. The electrode slurry coating system according to claim 1 or 2.

4. a loading amount measuring device for measuring a loading amount of the electrode slurry to be coated on the electrode; When the correction constant A is not determined, the calculation unit 4. The electrode slurry coating system according to claim 3, wherein the correction constant A in the formula 1 is calculated from the measured value of the electrode slurry loading amount measured by the loading amount measuring device and the predicted value of the electrode slurry loading amount calculated by substituting the measured value into the formula 1.

5. The electrode slurry coating system according to claim 2 , wherein the control unit controls to adjust the RPM of the pump until the calculated predicted value of the electrode slurry loading amount satisfies a loading amount management range.

6. 6. The electrode slurry coating system according to claim 1, wherein the control unit controls the electrode coating process to start or continue when the calculated predicted value of the electrode slurry loading amount satisfies a loading amount management range.

7. 6. The electrode slurry coating system according to claim 1, wherein the control unit controls to generate an alarm sound when the calculated predicted value of the electrode slurry loading amount does not satisfy a loading amount management range.

8. 10. The electrode slurry coating system of claim 1, further comprising a human-machine interface for communication with the control unit.

9. (a) setting coating process conditions according to an electrode model; (b) setting the RPM of the pump; (c) test-coating the electrode slurry onto an electrode substrate according to the set coating process conditions; (d) a determination step of determining whether the predicted value of the electrode slurry loading amount satisfies the electrode slurry loading amount management range; (e) a coating step of starting a coating process to coat the electrode slurry when it is determined that the condition is met in the determining step, (c) test coating the electrode slurry, (c-1) measuring the flow rate of the electrode slurry and the density of the electrode slurry; (c-2) calculating a predicted loading amount of the electrode slurry based on the measurement information.

10. 10. The electrode slurry coating method according to claim 9, wherein in (c-1) the step of measuring the flow rate and density of the electrode slurry, the flow rate and density of the electrode slurry are measured by a mass flow meter installed on a route of the supply piping.

11. (c-2) In the step of calculating a predicted value of the electrode slurry loading amount, the flow rate value of the electrode slurry and the density value of the electrode slurry are substituted into the following Formula 1 and / or Formula 2 to calculate the predicted value of the electrode slurry loading amount: [Formula 1] Predicted loading amount = [Flow rate of electrode slurry × {1 - (density of solvent in electrode slurry / density of electrode slurry)}] / A [Formula 2] Predicted loading amount = [Flow rate of electrode slurry × {Solid concentration of electrode slurry / (Coating width length of electrode slurry × Coating speed of electrode slurry)}] + B 11. The electrode slurry coating method according to claim 9 or 10.

12. 11. The electrode slurry coating method according to claim 9, wherein if it is determined in the determining step (d) that the condition is not satisfied, steps (b) to (d) are repeated until it is determined in the determining step (d) that the condition is satisfied.

13. (b) setting the pump RPM by When the correction constant A of the formula 1 is determined, the RPM of the pump is set so that the predicted value of the electrode slurry loading amount in the formula 1 satisfies the target value of the electrode slurry loading amount; 12. The electrode slurry coating method according to claim 11, further comprising the step of: when the correction constant A in Equation 1 is not determined, setting the RPM of the pump so that the predicted value of the electrode slurry loading amount calculated according to Equation 2 satisfies the target value of the electrode slurry loading amount.

14. The electrode slurry coating method according to claim 11, further comprising: (f) a loading amount measuring step of measuring a loading amount of the electrode slurry applied onto the electrode substrate.

15. 15. The electrode slurry coating method according to claim 14, further comprising the step of: when the correction constant A of Equation 1 is not determined, calculating the correction constant A of Equation 1 so that a predicted electrode slurry loading amount calculated by substituting the correction constant A into Equation 1 becomes equal to the measured electrode slurry loading amount.

16. When the correction constant A in the above formula 1 is determined, 15. The electrode slurry coating method according to claim 14, further comprising the step of recalculating the correction constant A of Equation 1 when a difference between the predicted electrode slurry loading amount calculated according to Equation 1 and the measured electrode slurry loading amount measured in the loading amount measuring step (f) exceeds a reference range.

17. (e) the coating step (e-1) measuring the flow rate of the electrode slurry and the density of the electrode slurry; (e-2) calculating a predicted value of the electrode slurry loading amount based on the measurement information; (e-3) a determination step of determining whether the predicted value of the electrode slurry loading amount satisfies the electrode slurry loading amount management range; (e-4) a step of readjusting the RPM of the pump when it is determined in the determining step that the condition is not satisfied.

18. 11. The electrode slurry coating method according to claim 9, wherein the coating process conditions include one or more of a target loading amount of the electrode slurry, a coating speed of the electrode slurry, a coating width length, and a solids concentration of the electrode slurry.

Images