Secondary battery manufacturing equipment and method for manufacturing secondary battery by using same

Abstract

Provided, according to exemplary embodiments, is a method for manufacturing a secondary battery. This method comprises the steps of: turning off a circulation valve installed in a circulation pipe connecting a filter with an electrode slurry supply tank; measuring the pressure of a supply pipe connecting the electrode slurry supply tank with a die coater; measuring the pressure of the supply pipe adjacent to a supply valve; and turning on the supply pipe installed on the supply valve, on the basis of the measured value of the pressure of the supply pipe.

Description

Secondary battery manufacturing equipment and method for manufacturing secondary batteries using the same

[0001] The present invention relates to a secondary battery manufacturing facility and a method for manufacturing a secondary battery using the same. This application claims the benefit of Korean Application No. 10-2024-0047183, filed April 8, 2024, which is incorporated herein by reference in its entirety.

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0003] Secondary batteries are manufactured through electrode processes, assembly processes, and activation processes. Among these, the electrode process is the most critical process in determining the yield and performance of the battery cell. The electrode process may include a mixing process, a coating process, a roll-pressing process, and a slitting process. In the mixing process, an electrode slurry containing an active material, a conductive material, and a binder may be provided. In the coating process, the active material and an insulating material may be applied to the surface of a current collector. In the roll-pressing process, the electrode may be pressed by rolling rolls. The roll-pressing process may determine the density, performance, and surface quality of the electrode. In the slitting process, the electrode may be cut into multiple electrodes depending on the battery cell design.

[0004] The technical idea of ​​the present invention aims to solve a problem by providing a secondary battery manufacturing facility with improved productivity and a method for manufacturing a secondary battery using the facility.

[0005] According to exemplary embodiments of the present invention for solving the above-described problem, a method for manufacturing a secondary battery is provided. The method includes the steps of turning off a circulation valve installed in a circulation pipe connecting a filter and an electrode slurry supply tank; and the steps of measuring the pressure of a supply pipe connecting the electrode slurry supply tank and a die coater; the step of measuring the pressure of a supply pipe adjacent to a supply valve; and the step of turning on a supply pipe installed in the supply valve based on the measured pressure of the supply pipe.

[0006] The step of turning on the supply valve comprises comparing the measured value of the pressure of the supply pipe with a threshold pressure.

[0007] The above critical pressure is equal to the steady-state pressure of the above supply pipe.

[0008] The above critical pressure is different from the steady-state pressure of the above supply pipe.

[0009] The above critical pressure is greater than the above steady-state pressure.

[0010] The above critical pressure is less than the above steady state pressure.

[0011] The critical pressure is 70% or more of the steady-state pressure, and the critical pressure is 80% or less of the steady-state pressure.

[0012] The distance between the filter and the circulation valve is smaller than the distance between the filter and the supply valve.

[0013] The above circulation pipe connects the branch pipe and the electrode slurry supply tank, and the above supply pipe connects the branch pipe and the die coater.

[0014] The pressure of the above supply pipe is measured by a pressure gauge installed in the above supply valve, and the pressure gauge is adjacent to the die coater.

[0015] The length of the supply pipe between the pressure gauge and the die coater is shorter than the length of the supply valve between the pressure gauge and the branch pipe.

[0016] According to exemplary embodiments, a secondary battery manufacturing facility is provided. The facility includes: an electrode slurry supply tank configured to store electrode slurry; a filter configured to filter electrode slurry flowing from the electrode slurry supply tank; a die coater configured to apply the electrode slurry onto an electrode current collector; a first supply pipe connecting the electrode slurry supply tank and the filter; a second supply pipe connecting the filter and a branch pipe; a third supply pipe connecting the branch pipe and the die coater; a circulation pipe connecting the branch pipe and the electrode slurry supply tank; a pressure gauge installed in the third supply pipe and configured to measure a pressure of the third supply pipe; a supply valve installed in the third supply pipe and configured to allow or block a flow of the electrode slurry through the third supply pipe; a circulation valve installed in the circulation pipe and configured to allow or block a flow of the electrode slurry through the circulation pipe; and a controller configured to generate a signal for turning on the supply valve based on a measured value of the pressure.

[0017] The above pressure gauge is adjacent to the die coater.

[0018] The length of the supply pipe between the pressure gauge and the die coater is shorter than the length of the supply valve between the pressure gauge and the branch pipe.

[0019] The controller is configured to compare the measured value of the pressure with a threshold pressure, and the controller is configured to generate the signal for turning on the supply valve when the measured value of the pressure is greater than or equal to the threshold pressure.

[0020] The above critical pressure is different from the steady-state pressure of the above supply pipe.

[0021] The above critical pressure is less than the steady-state pressure of the above supply pipe.

[0022] The critical pressure is 70% or more of the steady-state pressure, and the critical pressure is 80% or less of the steady-state pressure.

[0023] According to exemplary embodiments of the present invention, a supply valve can be turned on based on a pressure measurement of a portion of a supply pipe adjacent to a die coater. Accordingly, when the pressure within the supply pipe is within an appropriate numerical range, electrode slurry can be supplied, thereby improving the yield of the coating process.

[0024] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0025] Figure 1 illustrates a secondary battery manufacturing facility according to exemplary embodiments.

[0026] FIGS. 2 and 3 are flowcharts illustrating a method for manufacturing a secondary battery according to exemplary embodiments.

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0028] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0029] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0030] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0031] Furthermore, the connection of an element to another element is not limited to a state of direct physical contact, and includes cases where additional connecting elements are interposed in the middle. In other words, the connection used below may include not only a direct connection but also an indirect connection, unless otherwise specified. For example, when elements A and B are connected to each other, a C element may be provided between elements A and C, each of which is connected to elements A and C.

[0032]

[0033] (Example 1)

[0034] FIG. 1 illustrates a secondary battery manufacturing facility (100) according to exemplary embodiments.

[0035] Referring to FIG. 1, the secondary battery manufacturing facility (100) may include an electrode slurry supply tank (110), a filter (120), supply pipes (131, 133, 135), a branch pipe (134), a circulation pipe (137), a pressure gauge (140), a supply valve (151), a circulation valve (153), a die coater (160), and a controller (170).

[0036] According to exemplary embodiments, a secondary battery manufacturing facility (100) may be configured to perform a process for manufacturing a secondary battery. The secondary battery manufacturing facility (100) may be an electrode slurry supply system. The secondary battery manufacturing facility (100) may be configured to perform a coating process of applying a negative electrode slurry or a positive electrode slurry onto an electrode.

[0037] The secondary battery manufacturing facility (100) may further include a mixer. The mixer may be configured to perform a mixing process. The mixing process may include a pre-mixing process for dissolving a binder and / or a conductive material in a solvent before introducing the binder and / or conductive material into the main mixer, and a main mixing process for finally mixing the active material, conductive material, binder, etc. to provide an electrode slurry.

[0038] Here, an electrode slurry can be used in a coating process of a secondary battery. The electrode slurry can include an electrode active material, a conductive agent, a binder, and a solvent. The electrode slurry can be prepared by dissolving the electrode active material, the conductive agent, and the binder in a solvent. The solvent can disperse the electrode active material, the binder, and the conductive agent. The solvent can be an aqueous solvent or a non-aqueous solvent. The solvent can include any one of dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, and mixtures thereof. The amount of the solvent used can be determined based on the target viscosity of the electrode slurry. Parameters determining the amount of the solvent used include the coating thickness of the electrode slurry, the manufacturing yield, and the workability.

[0039] A cathode active material is a material that can cause an electrochemical reaction. The cathode active material may be a lithium transition metal oxide. The cathode active material may be, for example, a layered compound such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2) substituted with one or more transition metals, lithium manganese oxide substituted with one or more transition metals, or a lithium manganese oxide having the chemical formula LiNi. 1-y M y Lithium nickel oxide, Li, expressed as O2 (wherein, M is any one of Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn, and Ga, and 0.01≤y≤0.7) 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, Li 1+zN i 0.4 Mn 0.4 Co 0.2 Li like O2 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e(wherein, -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b+c+d<1, M is any one of Al, Mg, Cr, Ti, Si and Y, and A is any one of F, P and Cl) lithium nickel cobalt manganese composite oxide, and chemical formula Li 1+x M 1-y M' y PO 4-z X z (wherein, M is a transition metal, more specifically, one of Fe, Mn, Co, and Ni, M' is one of Al, Mg, and Ti, X is one of F, S, and N, -0.5≤x≤+0.5, 0≤y≤0.5, and 0≤z≤0.1) and may include one of the olivine-based lithium metal phosphates.

[0040] The negative active material may include carbon, such as non-graphitizable carbon, graphitic carbon, etc. The negative active material may include, for example, Li x Fe2O3(0≤x≤1), LixWO2(0≤x≤1), Sn x Me 1-x Me' y O z(Here, Me is any one of Mn, Fe, Pb, and Ge, and Me' is any one of Al, B, P, Si, elements of group 1, 2, and 3 of the periodic table, and halogens, and 0 <x≤1 이고, 1≤y≤3 이며, 1≤z≤8) 등의 금속 복합 산화물을 포함할 수 있다. 음극 활물질은, 예컨대, 리튬 금속, 리튬 합금, 규소계 합금, 및 주석계 합금 중 어느 하나를 포함할 수 있다. 음극 활물질은, 예컨대, SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4및 Bi2O5등의 금속 산화물을 포함할 수 있다. 음극 활물질은, 예컨대, 폴리아세틸렌 등의 도전성 고분자, Li-Co-Ni 계 재료 등을 포함할 수도 있다.

[0041] The conductive material can have conductivity without causing a chemical change in the secondary battery ultimately manufactured. The conductive material may include, for example, graphite such as natural graphite or artificial graphite, carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black, conductive fibers such as carbon fiber or metal fiber, metal powders such as fluorocarbon, aluminum, and nickel powder, conductive whiskey such as zinc oxide or potassium titanate, conductive metal oxides such as titanium oxide, polyphenylene derivatives, and the like.

[0042] The binder can enhance the bonding between the active material and the conductive material and the bonding strength to the current collector. The binder can include, for example, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluoroelastomer, various copolymers, and the like.

[0043] The electrode slurry supply tank (110) may be configured to store electrode slurry. The electrode slurry supply tank (110) may be configured to supply the electrode slurry to a die coater (160). The electrode slurry supply tank (110) may include a stirrer configured to stir the electrode slurry. The physical properties of the electrode slurry, such as viscosity, may be maintained by the operation of the stirrer. The electrode slurry supply tank (110) may include an input pipe into which the electrode slurry is input. The input pipe may include, but is not limited to, a metering pipe.

[0044] A supply pipe (131) may connect the electrode slurry supply tank (110) and the filter (120). The supply pipe (131) may be connected to each of the electrode slurry supply tank (110) and the filter (120). The electrode slurry inside the electrode slurry supply tank (110) may be delivered to the filter (120) through the supply pipe (131). The filter (120) may be configured to remove impurities in the electrode slurry or block a portion of the electrode slurry based on particle size. The operation of the filter (120) may provide reliability and uniformity of the coating process.

[0045] The supply pipe (133) can connect the filter (120) and the branch pipe (134). The electrode slurry that has passed through the filter (120) can be delivered to the branch pipe (134) through the supply pipe (133). The branch pipe (134) can be a 3-way pipe. The branch pipe (134) can be connected to each of the supply pipes (133, 135) and the circulation pipe (137). Accordingly, the electrode slurry flowing through the supply pipe (133) can flow to the supply pipe (135) or to the circulation pipe (137).

[0046] The supply pipe (135) can be connected to the branch pipe (134) and the die coater (160). The die coater (160) can be supplied with electrode slurry stored in the electrode slurry storage tank (110) through the supply pipe (135) and can be configured to perform a coating process.

[0047] More specifically, the coating process may include applying an electrode slurry containing an electrode active material onto a current collector, drying, and rolling to form an electrode mixture layer. The die coater (160) may be, for example, a slot die. The current collector may be a positive electrode current collector or a negative electrode current collector, and the electrode active material may be a positive electrode active material or a negative electrode active material.

[0048] The thickness of the positive electrode current collector may range from about 3 μm to about 500 μm. The positive electrode current collector may not cause chemical changes in the secondary battery to be ultimately manufactured and may have high conductivity. The positive electrode current collector may include, for example, any one of stainless steel, aluminum, nickel, titanium, calcined carbon, and aluminum. The positive electrode current collector may also include stainless steel surface-treated with carbon, nickel, titanium, silver, or the like. The surface of the positive electrode current collector may include a micro-roughened structure to increase the adhesion of the active material. The shape of the positive electrode current collector may include any one of a film, a sheet, a foil, a net, a porous material, a foam, and a non-woven fabric.

[0049] The thickness of the negative electrode current collector may be in the range of about 3 μm to about 500 μm. The negative electrode current collector may not cause chemical changes in the secondary battery to be ultimately manufactured and may have high conductivity. The negative electrode current collector may include any one of copper, stainless steel, aluminum, nickel, titanium, sintered carbon, and an aluminum-cadmium alloy. The negative electrode current collector may also include stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The surface of the negative electrode current collector may include a micro-roughened structure to increase the adhesion of the active material. The shape of the negative electrode current collector may include any one of a film, a sheet, a foil, a net, a porous material, a foam, and a non-woven fabric.

[0050] The circulation pipe (137) can be connected to the branch pipe (134) and the electrode slurry supply tank (110). Accordingly, when the secondary battery manufacturing facility is in circulation mode, the electrode slurry can be circulated between the electrode slurry supply tank (110) and the filter (120) through the supply pipes (131, 133) and the circulation pipe (137), thereby preventing deterioration of the properties of the electrode slurry, such as viscosity.

[0051] A pressure gauge (140) may be installed in the supply pipe (135). The pressure gauge (140) may be configured to measure the pressure inside the supply pipe (135). The pressure gauge (140) may be adjacent to the die coater (160). Accordingly, the pressure of the portion of the supply pipe (135) adjacent to the die coater (160) may be monitored, and a pressure similar to the pressure applied to the die coater (160) may be monitored, thereby improving the reliability of pressure-based supply control.

[0052] According to exemplary embodiments, the length of the supply pipe (135) between the pressure gauge (140) and the die coater (160) may be different from the length of the supply pipe (135) between the pressure gauge (140) and the branch pipe (134). According to exemplary embodiments, the length of the supply pipe (135) between the pressure gauge (140) and the die coater (160) may be shorter than the length of the supply pipe (135) between the pressure gauge (140) and the branch pipe (134).

[0053] The pressure gauge (140) may be a seamless pressure gauge. A seamless pressure gauge may have a seal and gauge processed by a method such as welding, thereby preventing or alleviating fluid leakage. The pressure gauge (140) may be configured to transmit measured pressure to the controller (170) based on wireless communication, but is not limited thereto. A communication line may also be installed to transmit pressure data between the pressure gauge (140) and the controller (170).

[0054] The pressure gauge (140) may be configured to operate based on a preset monitoring cycle. The pressure gauge (140) may be configured to measure the pressure of the supply pipe (135) each time the monitoring cycle arrives and transmit the measured pressure to the controller, thereby collecting pressure data (PMD).

[0055] A supply valve (151) may be installed in the supply pipe (135). The supply valve (151) may be configured to allow or block the flow of electrode slurry from the supply pipe (135) to the die coater (160). The supply valve (151) may be an electronic valve. The supply valve (151) may operate based on a control signal from the controller (170). The supply valve (151) may be turned on or off based on the control signal from the controller (170).

[0056] A circulation valve (153) may be installed in the circulation pipe (137). The circulation valve (153) may be configured to allow or block the flow of electrode slurry from the circulation pipe (137) to the electrode slurry supply tank (110). The circulation valve (153) may be an electronic valve. The circulation valve (153) may operate based on a control signal from the controller (170). The circulation valve (153) may be turned on or off based on the control signal from the controller (170).

[0057] The circulation valve (153) may be closer to the electrode slurry supply tank (110) and the filter (120) than the supply valve (151). The distance between the circulation valve (153) and the electrode slurry supply tank (110) may be different from the distance between the supply valve (151) and the electrode slurry supply tank (110). The distance between the circulation valve (153) and the electrode slurry supply tank (110) may be smaller than the distance between the supply valve (151) and the electrode slurry supply tank (110). The distance between the circulation valve (153) and the filter (120) may be different from the distance between the supply valve (151) and the filter (120). The distance between the circulation valve (153) and the filter (120) may be smaller than the distance between the supply valve (151) and the filter (120).

[0058] The secondary battery manufacturing facility (100) may be in supply mode or in circulation mode. The secondary battery manufacturing facility (100) may switch from supply mode to circulation mode, or from circulation mode to supply mode, based on the turn-on and turn-off operations of the supply valve (151) and the circulation valve (153).

[0059] In the supply mode of the secondary battery manufacturing facility (100), the supply valve (151) can allow the flow of electrode slurry through the supply pipe (135), and the circulation valve (153) can block the flow of electrode slurry through the circulation pipe (137). Accordingly, a flow path of electrode slurry including an electrode slurry supply tank (110), a supply pipe (131), a filter (120), a supply pipe (133), a branch pipe (134), a supply pipe (135), and a die coater (160) can be provided, and the electrode slurry stored in the electrode slurry supply tank (110) can be provided to the die coater (160).

[0060] In the circulation mode of the secondary battery manufacturing facility (100), the supply valve (151) can block the flow of electrode slurry through the supply pipe (135), and the circulation valve (153) can allow the flow of electrode slurry through the circulation pipe (137). Accordingly, a circulation path of the electrode slurry can be provided, including the electrode slurry supply tank (110), the supply pipe (131), the filter (120), the supply pipe (133), the branch pipe (134), and the circulation pipe (137). Accordingly, the electrode slurry can flow in a circulating manner between the electrode slurry supply tank (110) and the filter (120).

[0061] In order for the secondary battery manufacturing facility (100) to switch from supply mode to circulation mode, the supply valve (151) may be turned off and the circulation valve (153) may be turned on. In order for the secondary battery manufacturing facility (100) to switch from circulation mode to supply mode, the circulation valve (153) may be turned off and the supply valve (151) may be turned on.

[0062] The controller (170) may be configured to generate signals for controlling various elements of the secondary battery manufacturing facility (100), including the supply valve (151) and the circulation valve (153), based on a user's operation or a predetermined recipe. The controller (170) may be configured to receive pressure data measured by the pressure gauge (140). The controller (170) may be configured to generate signals for controlling the supply valve (151) based on the pressure data.

[0063] The controller (170) may be a Programmable Logic Controller (PLC). A PLC is a specialized type of microprocessor-based controller that uses programmable memory to store commands and implement functions such as logic, sequencing, timing, counting, and arithmetic to control machines and processes. PLCs are easy to operate and program.

[0064] The controller (170) may include a power supply, a central processing unit (CPU), an input interface, an output interface, a communication interface, and memory devices. The power supply may be configured to supply power to other elements of the controller, such as the CPU, the input interface, the output interface, the communication interface, and the memory devices, for the operation of the controller. The memory devices may include a read-only memory (ROM) configured to store a system program, such as an operating system, and a random access memory (RAM) configured to store data, such as user programs and status information of input and output devices, timers, counters, and other internal device values. The CPU may be configured to control communication between modules that implement logic and convert input signals into output operation signals. The CPU may operate based on the system program and the user program stored in the memory devices. The CPU may be configured to write or read inspection data and measurement data to the data area of ​​the memory devices based on the system program and the user program. Conditions or data of industrial devices and production processes may be transmitted to the CPU through the input module. The results processed by the CPU can be transmitted to the actuator via an output module. The communication interface can be configured to relay data transmission and reception between the controller and other network elements.

[0065] However, the controller (170) is not limited thereto, and may include any one of a simple controller, a complex processor such as a microprocessor, a CPU, a GPU, a processor configured by software, dedicated hardware, and firmware. The controller may be implemented by, for example, a general-purpose computer or application-specific hardware such as a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

[0066] The secondary battery manufacturing facility (100) may further include a pump. The pump may be configured to provide power for the flow and circulation of the electrode slurry in the circulation mode and supply mode of the secondary battery manufacturing facility (100).

[0067]

[0068] (Example 2)

[0069] FIG. 2 is a flowchart illustrating a method for manufacturing a secondary battery according to exemplary embodiments.

[0070] FIG. 3 is a flowchart illustrating a method for manufacturing a secondary battery according to exemplary embodiments.

[0071] Referring to FIGS. 1 to 3, at P110, the circulation valve (153) can be turned off. The controller (170) can be configured to generate a first signal (S1) for turning off the circulation valve (153) and transmit the first signal (S1) to the circulation valve (153). The circulation valve (153) can receive the first signal (S1) and be turned off based on the first signal (S1). The first signal (S1) can be generated based on an operator's operation or a preset process recipe.

[0072] Next, at P120, the supply valve (151) can be turned on based on the pressure data (PMD). If the flow of the electrode slurry through the circulation pipe (137) is blocked at P110, the electrode slurry can flow into the supply pipe (135), and thus, the pressure in the supply pipe (135) can increase.

[0073] When the supply valve (151) is turned on, if the pressure inside the supply pipe (135) is excessively low, the loading amount of the electrode slurry may fall short of the target loading amount range, or the lateral distribution and discharge of the electrode slurry may be hindered. When the lateral distribution and discharge of the electrode slurry are hindered, the electrode yield may be reduced due to poor coating of the electrode slurry retention portion. When the pressure inside the supply pipe (135) is excessively high when the supply valve (151) is turned on, the loading amount of the electrode slurry may exceed the target loading range, or the lateral distribution and discharge of the electrode slurry may be excessive. When the lateral distribution and discharge of the electrode slurry are excessive, the electrode yield may be reduced due to coating of the uncoated portion of the electrode current collector.

[0074] According to exemplary embodiments, the controller (170) may be configured to generate a second signal (S2) for turning on the supply valve (151) based on the pressure data (PMD) after transmitting the first signal (S1). Accordingly, when turning on the supply valve (151), the pressure inside the supply pipe (135) can be prevented from being excessively low or excessively high, and the reliability of the coating process can be improved.

[0075] Referring to FIG. 3, P120 may include monitoring pressure data (PMD) at P121, comparing the measured value of the pressure data (PMD) with a threshold pressure at P123, and turning on the supply valve (151) at P125.

[0076] Pressure data (PMD) can be collected based on a monitoring cycle, and each time the pressure data (PMD) is updated after the circulation valve (153) is turned off, the controller (170) can be configured to compare the updated measurement of the pressure data (PMD) with a threshold pressure. If the updated measurement of the pressure data (PMD) is below the threshold pressure, the pressure data (PMD) can be monitored again at P121.

[0077] If the updated measurement of the pressure data (PMD) is above the threshold pressure, the controller (170) at P125 can generate a second signal (S2) to turn on the supply valve (151), and accordingly, the supply valve (151) can be turned on.

[0078] According to exemplary embodiments, the threshold pressure may be determined based on a steady-state pressure determined based on pressure data (PMD) of the supply mode of the secondary battery manufacturing facility (100). Here, the steady-state pressure is a pressure measured by a pressure gauge (140) after a sufficient time has passed since the secondary battery manufacturing facility (100) started operating in the supply mode (i.e., after the transient state has ended), and may have a constant pressure value or a range of constant pressure values.

[0079] According to exemplary embodiments, the threshold pressure may be different from the steady-state pressure. According to exemplary embodiments, the threshold pressure may be lower than the steady-state pressure. According to exemplary embodiments, the threshold pressure may be in a range from about 50% to about 100% of the steady-state pressure. According to exemplary embodiments, the threshold pressure may be greater than or equal to about 60% of the steady-state pressure. According to exemplary embodiments, the threshold pressure may be greater than or equal to about 70% of the steady-state pressure. According to exemplary embodiments, the threshold pressure may be less than or equal to about 90% of the steady-state pressure. According to exemplary embodiments, the threshold pressure may be less than or equal to about 80% of the steady-state pressure.

[0080] According to exemplary embodiments, since the critical pressure is within the numerical range described above with respect to the steady-state pressure, the duration of the transient state until the pressure within the supply pipe (135) reaches the steady-state can be reduced or minimized, thereby improving the performance of the coating process.

[0081] According to other exemplary embodiments, the threshold pressure may be substantially equal to the steady-state pressure. According to other exemplary embodiments, the threshold pressure may be higher than the steady-state pressure.

[0082]

[0083] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. A step of turning off the circulation valve installed in the circulation pipe connecting the filter and the electrode slurry supply tank; and A step of measuring the pressure of a supply pipe connecting the electrode slurry supply tank and the die coater; A step of measuring the pressure of the supply pipe adjacent to the supply valve; and A method for manufacturing a secondary battery, characterized in that it comprises a step of turning on a supply pipe installed in the supply valve based on a measured value of the pressure of the supply pipe.

2. In paragraph 1, A method for manufacturing a secondary battery, characterized in that the step of turning on the supply valve includes comparing the measured value of the pressure of the supply pipe with a threshold pressure.

3. In paragraph 2, A method for manufacturing a secondary battery, wherein the critical pressure is equal to the steady-state pressure of the supply pipe.

4. In paragraph 2, A method for manufacturing a secondary battery, wherein the critical pressure is different from the normal state pressure of the supply pipe.

5. In paragraph 4, A method for manufacturing a secondary battery, characterized in that the critical pressure is greater than the normal state pressure.

6. In paragraph 4, A method for manufacturing a secondary battery, characterized in that the critical pressure is smaller than the normal state pressure.

7. In paragraph 6, The above critical pressure is 70% or more of the above steady-state pressure, and A method for manufacturing a secondary battery, characterized in that the critical pressure is 80% or less of the normal state pressure.

8. In paragraph 1, A method for manufacturing a secondary battery, characterized in that the distance between the filter and the circulation valve is smaller than the distance between the filter and the supply valve.

9. In paragraph 1, The above circulation pipe connects the branch pipe and the electrode slurry supply tank, and A method for manufacturing a secondary battery, characterized in that the supply pipe connects the branch pipe and the die coater.

10. In paragraph 9, The pressure of the above supply pipe is measured by a pressure gauge installed in the above supply valve, and A method for manufacturing a secondary battery, wherein the pressure gauge is adjacent to the die coater.

11. In paragraph 10, A method for manufacturing a secondary battery, characterized in that the length of the supply pipe between the pressure gauge and the die coater is shorter than the length of the supply valve between the pressure gauge and the branch pipe.

12. An electrode slurry supply tank configured to store electrode slurry; A filter configured to filter electrode slurry flowing from the electrode slurry supply tank; A die coater configured to apply the electrode slurry onto an electrode current collector; A first supply pipe connecting the electrode slurry supply tank and the filter; A second supply pipe connecting the above filter and branch pipe; A third supply pipe connecting the above branch pipe and the die coater; A circulation pipe connecting the above branch pipe and the electrode slurry supply tank; A pressure gauge installed in the third supply pipe and configured to measure the pressure of the third supply pipe; A supply valve installed in the third supply pipe and configured to allow or block the flow of the electrode slurry through the third supply pipe; A circulation valve installed in the above circulation pipe and configured to allow or block the flow of the electrode slurry through the above circulation pipe; and A secondary battery manufacturing facility comprising a controller configured to generate a signal for turning on the supply valve based on a measurement of the pressure.

13. In paragraph 12, A secondary battery manufacturing facility characterized in that the pressure gauge is adjacent to the die coater.

14. In paragraph 13, A secondary battery manufacturing facility, characterized in that the length of the supply pipe between the pressure gauge and the die coater is shorter than the length of the supply valve between the pressure gauge and the branch pipe.

15. In paragraph 12, The controller is configured to compare the measured value of the pressure with a threshold pressure, and A secondary battery manufacturing facility, characterized in that the controller is configured to generate the signal for turning on the supply valve when the measured value of the pressure is greater than or equal to the threshold pressure.

16. In paragraph 15, A secondary battery manufacturing facility, characterized in that the above critical pressure is different from the normal state pressure of the supply pipe.

17. In paragraph 15, A secondary battery manufacturing facility, characterized in that the above critical pressure is smaller than the normal state pressure of the supply pipe.

18. In paragraph 17, The above critical pressure is 70% or more of the above steady-state pressure, and A secondary battery manufacturing facility, characterized in that the above critical pressure is 80% or less of the above normal state pressure.

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