Rechargeable battery manufacturing equipment and method for manufacturing rechargeable batteries using the same

Abstract

According to an exemplary embodiment, 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; measuring the pressure in a supply pipe connecting the electrode slurry supply tank and a die coater; measuring the pressure in a supply pipe adjacent to the supply valve; and turning on a supply pipe installed to the supply valve based on the measured pressure of the supply pipe.

Description

[Technical Field]

[0001] The present invention relates to a secondary battery manufacturing apparatus and a method for manufacturing a secondary battery using the same. This application claims the interests of Korean application No. 10-2024-0047183, filed on April 8, 2024, which is herein by reference in whole. [Background technology]

[0002] Unlike primary batteries, rechargeable batteries can be charged and discharged multiple times. Rechargeable batteries are widely used as an energy source for a variety of cordless devices such as handsets, laptops, and cordless vacuum cleaners. In recent years, improvements in energy density and economies of scale have dramatically reduced the manufacturing cost per unit capacity of rechargeable batteries, and as the driving range of battery electric vehicles (BEVs) increases to levels comparable to those of fuel-powered vehicles, the main applications of rechargeable batteries are shifting from mobile devices to mobility.

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

[0004] The technical concept of this invention aims to solve the problem of secondary battery manufacturing equipment with improved productivity and a method for manufacturing secondary batteries using the same. [Means for solving the problem]

[0005] According to an exemplary embodiment of the present invention for solving the above-mentioned problems, 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; measuring the pressure in a supply pipe connecting an electrode slurry supply tank and a die coater; measuring the pressure in a supply pipe adjacent to a supply valve; and turning on a supply valve installed in a supply pipe based on the measured pressure of the supply pipe.

[0006] The step of turning on the supply valve includes comparing the measured pressure in the supply piping with the critical pressure.

[0007] The critical pressure is the same as the steady-state pressure of the supply piping.

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

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

[0010] The critical pressure is lower than the steady-state pressure.

[0011] The critical pressure is 70% or more of the steady-state pressure, and 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 circulation piping connects the branch piping to the electrode slurry supply tank, and the supply piping connects the branch piping to the die coater.

[0014] The pressure of the supply pipe is measured by a pressure gauge installed in the supply pipe, 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 pipe between the pressure gauge and the branch pipe.

[0016] According to an exemplary embodiment, a secondary battery manufacturing facility is provided. The facility includes an electrode slurry supply tank configured to store a slurry, a filter configured to filter the 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 the 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 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 circulation pipe and configured to allow or block the 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 the measured value of the pressure.

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

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

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

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

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

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

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

[0024] The effects obtained from exemplary embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly derived and understood by a person ordinary in the art to which the exemplary embodiments of this disclosure belong from the following description. That is, unintended effects associated with carrying out exemplary embodiments of this disclosure can also be derived by a person ordinary in the art to which the exemplary embodiments of this disclosure belong from the exemplary embodiments of this disclosure. [Brief explanation of the drawing]

[0025] [Figure 1] This shows a secondary battery manufacturing facility according to an exemplary embodiment. [Figure 2] This is a flowchart illustrating a method for manufacturing a secondary battery according to an exemplary embodiment. [Figure 3] This is a flowchart illustrating a method for manufacturing a secondary battery according to an exemplary embodiment. [Modes for carrying out the invention]

[0026] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. As a premise, terms and words used herein and in the claims should not be interpreted in a manner limited to their general or dictionary meanings, but rather in a manner consistent with the technical spirit of the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their own invention.

[0027] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention; there are various equivalents and modifications that can substitute for them at the time of filing.

[0028] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, such detailed description will be omitted.

[0029] Since embodiments of the present invention are provided to give a more complete explanation to an ordinary person, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes and proportions.

[0030] Furthermore, the connection of one element to another is not limited to direct physical contact, but also includes cases where additional connecting elements are interposed. In other words, the term "connection" used below can include not only direct connections but also indirect connections, unless otherwise explicitly stated. For example, if elements A and B are connected to each other, then elements C may be provided between elements A and C, each connected to both elements A and C.

[0031] (First Embodiment) Figure 1 shows a secondary battery manufacturing facility 100 according to an exemplary embodiment.

[0032] Referring to Figure 1, the secondary battery manufacturing equipment 100 may include an electrode slurry supply tank 110, a filter 120, supply piping 131, 133, 135, branch piping 134, circulation piping 137, a pressure gauge 140, a supply valve 151, a circulation valve 153, a die coater 160, and a controller 170.

[0033] According to exemplary embodiments, the secondary battery manufacturing equipment 100 may be configured to perform processes for manufacturing secondary batteries. The secondary battery manufacturing equipment 100 may be an electrode slurry supply system. The secondary battery manufacturing equipment 100 may be configured to perform a coating process in which a negative electrode slurry or a positive electrode slurry is applied to the electrodes.

[0034] The secondary battery manufacturing equipment 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 in which the binder and / or conductive material is dissolved in a solvent before being introduced into the main mixer, and a main mixing process in which the active material, conductive material, binder, etc. are finally mixed to provide an electrode slurry.

[0035] Here, the electrode slurry can be used in the coating process of a secondary battery. The electrode slurry may contain an electrode active material, a conductive material, a binder, and a solvent. The electrode slurry can be produced by dissolving the electrode active material, conductive material, and binder in a solvent. The solvent can disperse the electrode active material, binder, and conductive material. The solvent may be an aqueous or non-aqueous solvent. The solvent may include one of the following: dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, and mixtures thereof. The amount of solvent used may be determined based on the target viscosity of the electrode slurry. Parameters for determining the amount of solvent used include the coating thickness of the electrode slurry, the production yield, and the workability.

[0036] The positive electrode active material is a substance that can undergo an electrochemical reaction. The positive electrode active material can be a lithium transition metal oxide. The positive electrode active material is, 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, chemical formula Li 1-y M y O2 (where M is any one of Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn and Ga, 0.01 ≦ y ≦ 0.7), lithium nickel-based oxide represented by, Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, Li 1+z Ni 0.4 Mn 0.4 Co 0.2 O2 such as Li 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e (where -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, A is any one of F, P and Cl), lithium nickel cobalt manganese composite oxide represented by, and chemical formula Li 1+x M 1-y M’ y PO 4-z X z (where M is a transition metal (more specifically, any one of Fe, Mn, Co and Ni), M’ is any one of Al, Mg and Ti, X is any one of F, S and N, -0.5 ≦ x ≦ +0.5, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 0.1), and may include any one of olivine-type lithium metal phosphates represented by.

[0037] The negative electrode active material can include carbon such as non-graphitizable carbon and graphite-based carbon. The negative electrode active material is, for example, Li x Fe2O3 (0 ≦ x ≦ 1), Lix WO₂(0 ≦ x ≦ 1), Sn x Me 1-x Me’ y O z (where Me is any one of Mn, Fe, Pb, and Ge, Me’ is any one of Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, and halogen, 0 < x ≦ 1, 1 ≦ y ≦ 3, 1 ≦ z ≦ 8), etc. may include metal composite oxides. The negative electrode active material may include, for example, any one of lithium metal, lithium alloy, silicon-based alloy, and tin-based alloy. The negative electrode active material may include, for example, metal oxides such as SnO, SnO₂, PbO, PbO₂, Pb₂O₃, Pb₃O₄, Sb₂O₃, Sb₂O₄, Sb₂O₅, GeO, GeO₂, Bi₂O₃, Bi₂O₄, and Bi₂O₅. The negative electrode active material may include, for example, conductive polymers such as polyacetylene, Li-Co-Ni-based materials, etc.

[0038] The conductive material does not induce chemical changes in the ultimately manufactured secondary battery and may have conductivity. The conductive material may include, for example, graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black, conductive fibers such as carbon fibers and metal fibers, carbon fluoride, metal powders such as aluminum and nickel powder, conductive whiskers such as zinc oxide and potassium titanate, conductive metal oxides such as titanium oxide, polyphenylene derivatives, etc.

[0039] The binder can improve the binding between the active material and the conductive material and the binding force to the current collector. The binder may 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-butadiene rubber, fluorine rubber, various copolymers, etc.

[0040] The electrode slurry supply tank 110 may be configured to store the electrode slurry. The electrode slurry supply tank 110 may be configured to supply the electrode slurry to the die coater 160. The electrode slurry supply tank 110 may include an agitator configured to stir the electrode slurry. The operation of the agitator may maintain the physical properties of the electrode slurry, such as viscosity. The electrode slurry supply tank 110 may include an input pipe into which the electrode slurry is introduced. The input pipe may include, but is not limited to, a metering pipe.

[0041] The supply pipe 131 can connect the electrode slurry supply tank 110 and the filter 120. The supply pipe 131 can be connected to both the electrode slurry supply tank 110 and the filter 120. The electrode slurry inside the electrode slurry supply tank 110 can be transmitted to the filter 120 through the supply pipe 131. The filter 120 can be configured to remove impurities from the electrode slurry or to block a portion of the electrode slurry based on particle size. The operation of the filter 120 can provide reliability and uniformity in the coating process.

[0042] 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 transmitted to the branch pipe 134 through the supply pipe 133. The branch pipe 134 may be a three-way pipe. The branch pipe 134 can be connected to each of the supply pipes 133, 135, and the circulation pipe 137. As a result, the electrode slurry flowing through the supply pipe 133 can flow into the supply pipe 135 or into the circulation pipe 137.

[0043] The supply pipe 135 may be connected to the branch pipe 134 and the die coater 160. The die coater 160 may be configured to receive electrode slurry stored in the electrode slurry storage tank 110 via the supply pipe 135 and perform the coating process.

[0044] More specifically, the coating process may include applying an electrode slurry containing electrode active material onto a current collector, drying and rolling it 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.

[0045] The thickness of the positive electrode current collector may range from approximately 3 μm to approximately 500 μm. The positive electrode current collector may not induce chemical changes in the final manufactured secondary battery and may have high conductivity. The positive electrode current collector may include, for example, one of stainless steel, aluminum, nickel, titanium, calcined carbon, and aluminum. The positive electrode current collector may include stainless steel surface-treated with carbon, nickel, titanium, and silver, etc. The surface of the positive electrode current collector may include a micro-textured structure to enhance the adhesion of the active material. The shape of the positive electrode current collector may include one of film, sheet, foil, net, porous material, foam, and nonwoven fabric.

[0046] The thickness of the negative electrode current collector may range from approximately 3 μm to approximately 500 μm. The negative electrode current collector may not induce chemical changes in the final manufactured secondary battery and may have high conductivity. The negative electrode current collector may contain one of the following: copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and aluminum-cadmium alloy. The negative electrode current collector may also contain stainless steel surface-treated with carbon, nickel, titanium, and silver, etc. The surface of the negative electrode current collector may include a micro-textured structure to enhance the adhesion of the active material. The shape of the negative electrode current collector may include one of the following: film, sheet, foil, net, porous material, foam, and nonwoven fabric.

[0047] The circulation pipe 137 can be connected to the branch pipe 134 and the electrode slurry supply tank 110. This allows the electrode slurry to circulate between the electrode slurry supply tank 110 and the filter 120 through the supply pipes 131, 133 and the circulation pipe 137 when the secondary battery manufacturing equipment is in circulation mode, thereby preventing deterioration of the electrode slurry's properties, such as viscosity.

[0048] The pressure gauge 140 may be installed in the supply piping 135. The pressure gauge 140 may be configured to measure the pressure inside the supply piping 135. The pressure gauge 140 may be adjacent to the die coater 160. This allows the pressure in the portion of the supply piping 135 adjacent to the die coater 160 to be monitored, and a pressure similar to the pressure applied to the die coater 160 can be monitored, thus improving the reliability of pressure-based supply control.

[0049] According to an exemplary embodiment, the length of the supply pipe 135 between the pressure gauge 140 and the die coater 160 may differ from the length of the supply pipe 135 between the pressure gauge 140 and the branch pipe 134. According to an exemplary embodiment, 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.

[0050] The pressure gauge 140 may be a seamless pressure gauge. In a seamless pressure gauge, the seal and gauge may be treated by methods such as welding, thereby preventing or mitigating fluid leakage. The pressure gauge 140 may, but is not limited to, be configured to transmit the measured pressure to the controller 170 based on wireless communication. A communication line may be installed for transmitting pressure data between the pressure gauge 140 and the controller 170.

[0051] 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 in the supply pipe 135 each time the monitoring cycle arrives and transmit the measured pressure to the controller, thereby allowing pressure data PMD to be collected.

[0052] The supply valve 151 may be installed in the supply piping 135. The supply valve 151 may be configured to allow or block the flow of electrode slurry from the supply piping 135 to the die coater 160. The supply valve 151 may be a solenoid 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 turned off based on a control signal from the controller 170.

[0053] The circulation valve 153 may be installed in the circulation piping 137. The circulation valve 153 may be configured to allow or block the flow of electrode slurry from the circulation piping 137 to the electrode slurry supply tank 110. The circulation valve 153 may be a solenoid 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 turned off based on a control signal from the controller 170.

[0054] The circulation valve 153 may be closer to the electrode slurry supply tank 110 and filter 120 than the supply valve 151. The distance between the circulation valve 153 and the electrode slurry supply tank 110 may differ 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 differ 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.

[0055] The secondary battery manufacturing equipment 100 may be in supply mode or circulation mode. The secondary battery manufacturing equipment 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.

[0056] In the supply mode of the secondary battery manufacturing equipment 100, the supply valve 151 may allow the flow of electrode slurry through the supply pipe 135, and the circulation valve 153 may block the flow of electrode slurry through the circulation pipe 137. This provides a flow path for electrode slurry including an electrode slurry supply tank 110, supply pipe 131, filter 120, supply pipe 133, branch pipe 134, supply pipe 135, and die coater 160, so that electrode slurry stored in the electrode slurry supply tank 110 can be supplied to the die coater 160.

[0057] In the circulation mode of the secondary battery manufacturing equipment 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. This provides a circulation path for the electrode slurry, 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. This allows the electrode slurry to flow in a circulating manner between the electrode slurry supply tank 110 and the filter 120.

[0058] In order for the secondary battery manufacturing equipment 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 equipment 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.

[0059] The controller 170 may be configured to generate signals for controlling elements of the secondary battery manufacturing equipment 100, including the supply valve 151 and the circulation valve 153, based on user 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.

[0060] Controller 170 may be a PLC (Programmable Logic Controller). A PLC is a special type of microprocessor-based controller that uses programmable memory to store instructions and controls machines and processes by performing functions such as logic, sequencing, timing, counting, and arithmetic. PLCs are easy to operate and program.

[0061] The controller 170 may include a power supply, a CPU (Central Processing Unit), an input interface, an output interface, a communication interface, and a memory device. The power supply may be configured to supply power to other components of the controller, such as the CPU, input interface, output interface, communication interface, and memory device, for the operation of the controller. The memory device may include a ROM (Read Only Memory) configured to store system programs such as an operating system, and a RAM (Random Access Memory) configured to store data such as user programs, information about the state of input / output devices, timers, counters, and other internal device values. The CPU may be configured to execute logic and control communication between modules that convert input signals into output operation signals. The CPU may operate based on system programs and user programs stored in the memory device. The CPU may be configured to write or read inspection data and measurement data to or from the data area of ​​the memory device based on the system programs and user programs. Conditions and data of industrial equipment and production processes may be transmitted to the CPU via the input module. The results processed by the CPU may be transmitted to the actuator via the output module. The communication interface may be configured to relay data transmission and reception between the controller and other network elements.

[0062] However, the controller 170 may include, but is not limited to, a simple controller, a microprocessor, a CPU, a complex processor such as a GPU (Graphics Processing Unit), a processor configured with software, dedicated hardware, and firmware. The controller may be implemented, for example, by a general-purpose computer or by application-specific hardware such as a DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), and ASIC (Application Specific Integrated Circuit).

[0063] The secondary battery manufacturing equipment 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 equipment 100.

[0064] (Second Embodiment) Figure 2 is a flowchart illustrating a method for manufacturing a secondary battery according to an exemplary embodiment.

[0065] Figure 3 is a flowchart illustrating a method for manufacturing a secondary battery according to an exemplary embodiment.

[0066] Referring to Figures 1 to 3, at P110, the circulation valve 153 can be turned off. The controller 170 may be configured to generate a first signal S1 for turning off the circulation valve 153 and to transmit the first signal S1 to the circulation valve 153. The circulation valve 153 receives the first signal S1 and may be turned off based on the first signal S1. The first signal S1 may be generated based on operator action or a preset process recipe.

[0067] Next, at P120, the supply valve 151 may be turned on based on the pressure data PMD. If the flow of electrode slurry through the circulation pipe 137 is interrupted at P110, the electrode slurry may flow into the supply pipe 135, which may increase the pressure in the supply pipe 135.

[0068] If the pressure inside the supply piping 135 is too low when the supply valve 151 is turned on, the loading amount of electrode slurry may not reach the target loading amount range, or the lateral dispersion and discharge of the electrode slurry may be inhibited. If the lateral dispersion and discharge of the electrode slurry are inhibited, the electrode yield may decrease due to poor coating of the coated portion of the electrode slurry. If the pressure inside the supply piping 135 is too high when the supply valve 151 is turned on, the loading amount of electrode slurry may exceed the target loading range, or the lateral dispersion and discharge of the electrode slurry may become excessive. If the lateral dispersion and discharge of the electrode slurry are excessive, the electrode yield may decrease due to coating of the uncoated portion of the electrode current collector.

[0069] According to an exemplary embodiment, the controller 170 may be configured to generate a second signal S2 for turning on the supply valve 151 based on pressure data PMD after the transmission of the first signal S1. This can prevent the pressure inside the supply piping 135 from being too low or too high when the supply valve 151 is turned on, thereby improving the reliability of the coating process.

[0070] Referring to Figure 3, P120 may include monitoring the pressure data PMD at P121, comparing the measured value of the pressure data PMD with the critical pressure at P123, and turning on the supply valve 151 at P125.

[0071] Pressure data PMD may 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 may be configured to compare the updated measurement of the pressure data PMD with the critical pressure. If the updated measurement of the pressure data PMD is below the critical pressure, the pressure data PMD may be monitored again at P121.

[0072] If the updated measurement of the pressure data PMD is above the critical pressure, the controller 170 at P125 may generate a second signal S2 to turn on the supply valve 151, thereby allowing the supply valve 151 to be turned on.

[0073] According to an exemplary embodiment, the critical pressure may be determined based on the steady-state pressure determined based on the supply mode pressure data (PMD) of the secondary battery manufacturing equipment 100. Here, the steady-state pressure is the pressure measured by the pressure gauge 140 after a sufficient amount of time has elapsed since the secondary battery manufacturing equipment 100 began operating in supply mode (i.e., after the transient state has ended), and may have a constant pressure value or a range of constant pressure values.

[0074] According to exemplary embodiments, the critical pressure may differ from the steady-state pressure. According to exemplary embodiments, the critical pressure may be lower than the steady-state pressure. According to exemplary embodiments, the critical pressure may be in the range of about 50% to about 100% of the steady-state pressure. According to exemplary embodiments, the critical pressure may be about 60% or more of the steady-state pressure. According to exemplary embodiments, the critical pressure may be about 70% or more of the steady-state pressure. According to exemplary embodiments, the critical pressure may be about 90% or less of the steady-state pressure. According to exemplary embodiments, the critical pressure may be about 80% or less of the steady-state pressure.

[0075] According to an exemplary embodiment, since the critical pressure is within the above-mentioned numerical range relative to the steady-state pressure, the duration of the transient state until the pressure in the supply pipe 135 reaches a steady state can be shortened or minimized, thereby improving the performance of the coating process.

[0076] According to other exemplary embodiments, the critical pressure may be substantially the same as the steady-state pressure. According to other exemplary embodiments, the critical pressure may be higher than the steady-state pressure.

[0077] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, at the time of filing, there may be various equivalents and modifications that can substitute for them.

Claims

1. The steps include turning off the circulation valve installed in the circulation piping connecting the filter and the electrode slurry supply tank, The steps include measuring the pressure in the supply piping connecting the electrode slurry supply tank and the die coater, A step of measuring the pressure in the supply piping adjacent to the supply valve, A method for manufacturing a secondary battery, comprising the step of turning on a supply valve installed in the supply pipe based on a measured value of the pressure in the supply pipe.

2. A method for manufacturing a secondary battery according to claim 1, wherein the step of turning on the supply valve includes comparing the measured value of the pressure in the supply pipe with the critical pressure.

3. The method for manufacturing a secondary battery according to claim 2, wherein the critical pressure is the same as the steady-state pressure of the supply piping.

4. The method for manufacturing a secondary battery according to claim 2, wherein the critical pressure is different from the steady-state pressure of the supply piping.

5. A method for manufacturing a secondary battery according to claim 4, wherein the critical pressure is higher than the steady-state pressure.

6. A method for manufacturing a secondary battery according to claim 4, wherein the critical pressure is lower than the steady-state pressure.

7. The critical pressure is 70% or more of the steady-state pressure. A method for manufacturing a secondary battery according to claim 6, wherein the critical pressure is 80% or less of the steady-state pressure.

8. A method for manufacturing a secondary battery according to any one of claims 1 to 7, wherein the distance between the filter and the circulation valve is smaller than the distance between the filter and the supply valve.

9. The aforementioned circulation piping connects the branch piping and the electrode slurry supply tank. A method for manufacturing a secondary battery according to any one of claims 1 to 7, wherein the supply piping connects the branch piping and the die coater.

10. The pressure in the supply pipe is measured by a pressure gauge installed in the supply pipe. The method for manufacturing a secondary battery according to claim 9, wherein the pressure gauge is adjacent to the die coater.

11. A method for manufacturing a secondary battery according to claim 10, wherein the length of the supply pipe between the pressure gauge and the die coater is shorter than the length of the supply pipe between the pressure gauge and the branch pipe.

12. An electrode slurry supply tank configured to store slurry, A filter configured to filter the 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 aforementioned filter and the branch pipe, A third supply pipe connecting the aforementioned branch pipe and the aforementioned die coater, A circulation pipe connecting the aforementioned branch pipe and the aforementioned electrode slurry supply tank, A pressure gauge installed in the third supply pipe and configured to measure the pressure in 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 circulation piping and configured to allow or block the flow of the electrode slurry through the circulation piping, A secondary battery manufacturing apparatus including a controller configured to generate a signal for turning on the supply valve based on the measured pressure.

13. The secondary battery manufacturing apparatus according to claim 12, wherein the pressure gauge is adjacent to the die coater.

14. The secondary battery manufacturing apparatus according to claim 13, wherein the length of the third supply pipe between the pressure gauge and the die coater is shorter than the length of the third supply pipe between the pressure gauge and the branch pipe.

15. The controller is configured to compare the measured pressure with the critical pressure. The secondary battery manufacturing apparatus according to any one of claims 12 to 14, wherein the controller is configured to generate the signal for turning on the supply valve when the measured value of the pressure is equal to or greater than the critical pressure.

16. The secondary battery manufacturing apparatus according to claim 15, wherein the critical pressure is different from the steady-state pressure of the third supply pipe.

17. The secondary battery manufacturing apparatus according to claim 15, wherein the critical pressure is lower than the steady-state pressure of the third supply pipe.

18. The critical pressure is 70% or more of the steady-state pressure. The secondary battery manufacturing apparatus according to claim 17, wherein the critical pressure is 80% or less of the steady-state pressure.

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