Electrode pressing condition inspection system

Abstract

According to embodiments of this disclosure, an electrode pressing condition inspection system using optical measurement is provided, comprising: a pair of pressing rollers located at an upper and lower part based on the electrode delivery position; a drive unit that drives the pair of pressing rollers; a first light source located on one side of the drive direction of the pair of pressing rollers and irradiating light toward the pair of pressing rollers; a first sensor located on the other side of the drive direction of the pair of pressing rollers and detecting light emitted from the first light source; and a control unit that analyzes surface information of the pair of pressing rollers and the gap between the pair of pressing rollers based on information acquired by the first sensor, wherein the first light source and the first sensor are respectively movable along the width direction of the pair of pressing rollers.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0150490, filed on October 30, 2024, and Korean Patent Application No. 10-2025-0116767, filed on August 21, 2025, the disclosure of which is incorporated herein by reference in its entirety.

[0003] This disclosure relates to an electrode pressing condition inspection system, and more specifically, to a system for inspecting electrode pressing condition using optical measurements before / after electrode pressing. Background Technology

[0004] In modern society, with the widespread use of portable devices such as mobile phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), the development of related technologies has been spurred. Furthermore, rechargeable / dischargeable secondary batteries are being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) in an attempt to address air pollution caused by the use of fossil fuels in existing gasoline vehicles. Therefore, the demand for secondary battery development is growing.

[0005] Currently, commercially available rechargeable batteries include nickel-cadmium (NiCd), nickel-metal hydride (NiMH), nickel-zinc (NiZn), and lithium-ion batteries. Among these, lithium-ion batteries have attracted considerable attention due to their advantages, such as being able to be freely charged and discharged, and exhibiting a very low self-discharge rate and high energy density.

[0006] Lithium-ion rechargeable batteries primarily use lithium-based oxides and carbon materials as the positive and negative electrode active materials, respectively. A lithium-ion rechargeable battery includes: an electrode assembly, in which positive and negative electrode plates, respectively coated with positive and negative electrode active materials, are separated by a separator; and an external material, namely the battery casing, which seals and houses the electrode assembly and the electrolyte solution together.

[0007] The manufacturing process of this type of lithium secondary battery can be broadly classified into three steps: electrode process, assembly process, and formation process. The electrode process can be further divided into active material mixing process, electrode coating process, pressing process, cutting process, and winding process. Among these, the pressing process involves passing the electrode substrate between a pair of heated pressing rollers and compressing it to the desired thickness. This reduces the thickness of the coated electrode substrate, thereby increasing the capacity density and improving the adhesion between the electrode current collector and the electrode active material.

[0008] Since the pressing process is performed by a pair of pressing rollers, it is inevitably greatly affected by the pressing conditions, such as the state of the pair of pressing rollers, the gap between them, and the roller drive speed.

[0009] Therefore, methods for adjusting the gap between a pair of pressure rollers are being actively researched. Specifically, when changing pressure rollers, a gap gauge with a reference thickness is used to store a reference gap position, and during the pressing process, the roller position is changed based on the reference gap position to adjust the gap. When product specifications do not match after manufacturing in this way, the roller position is corrected.

[0010] However, this method can only identify the relative positions of the initial pressing rollers during cold pressing, and therefore cannot reflect the reduction in clearance caused by roller expansion due to hot pressing and friction. In this case, the pressing conditions must be adjusted by referring to other indicators.

[0011] Therefore, various studies are being conducted on methods that can adjust the gap between a pair of pressure rollers in real time.

[0012] However, the specifications and quality of the electrodes obtained after the pressing process actually vary not only due to the thickness variation caused by the gap between the pair of rollers, but also due to various other factors. Therefore, there is a need to develop a technology that can improve the quality of the produced electrodes while maintaining constant quality. Summary of the Invention

[0013] [Technical Issues]

[0014] The purpose of this disclosure is to provide an electrode pressing condition inspection system that can not only inspect the surface characteristics of a pair of pressing rollers used in the pressing process before the pressing process and eliminate defects in the pair of pressing rollers, but also maintain a constant gap between them in real time during the actual pressing process, thereby improving the product quality of the produced electrodes and maintaining constant quality.

[0015] However, the technical objectives to be addressed by the embodiments of this disclosure are not limited to those described above, and various extensions can be made within the scope of the technical concepts included in this disclosure.

[0016] [Technical Solution]

[0017] According to the illustrative aspects of this disclosure, An electrode pressing condition inspection system using optical measurement is provided, comprising: A pair of pressure rollers, located at the top and bottom based on the electrode's conveying position, The drive unit drives a pair of pressure rollers. The first light source is located on one side of the driving direction of the pair of pressure rollers and shines light toward the pair of pressure rollers. A first sensor, located on the opposite side of the driving direction of a pair of pressing rollers, detects light emitted from a first light source, and The control unit analyzes the surface information of a pair of pressure rollers and the gap between them based on information obtained from the first sensor. The first light source and the first sensor are respectively capable of moving along the width direction of a pair of pressing rollers. Attached Figure Description

[0018] Figure 1 This is a perspective view of a suppression condition inspection system according to an embodiment of the present disclosure.

[0019] Figure 2 This is a flowchart of a suppression status inspection system according to an embodiment of the present disclosure.

[0020] Figure 3 This is a surface information diagram of a pair of pressure rollers that have been identified as normal.

[0021] Figure 4 This is a surface information diagram of a pair of pressure rollers that were identified as defective.

[0022] Figure 5 This is a schematic diagram of the longitudinal direction side of a pressing condition inspection system according to another embodiment of the present disclosure.

[0023] Figure 6 This is a schematic diagram of the width direction of a pressing condition inspection system according to another embodiment of the present disclosure. Detailed Implementation

[0024] Various embodiments of this disclosure will be described in detail below with reference to the accompanying drawings, enabling those skilled in the art to readily implement them. This disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0025] For clarity in describing this disclosure, parts irrelevant to the description will be omitted, and the same reference numerals will be used throughout the specification to denote the same or similar parts.

[0026] Furthermore, for ease of explanation, the dimensions and thicknesses of each component shown in the accompanying drawings are arbitrary. Therefore, this disclosure is not necessarily limited to the contents shown in the accompanying drawings.

[0027] Furthermore, throughout the specification, when a section is referred to as "including" a component, it means that the section may also include other components, without excluding other components, unless otherwise stated.

[0028] Furthermore, throughout the instruction manual, "one side" and "the other side" refer to the two sides that share a specific reference point. Additionally, "edge" refers to the end of a component.

[0029] Furthermore, throughout the specification, "width" refers to the length in the direction through the circle when the pressure roller is cut to have a circular cross-section. In the case of the sensor, "width" also refers to the length in the aforementioned direction. Conversely, "length" refers to the length from one side of the pressure roller to the other when viewed from the direction in which the electrode is inserted.

[0030] Figure 1 This is a perspective view of a suppression condition inspection system 100 according to an embodiment of the present disclosure.

[0031] refer to Figure 1 An electrode pressing condition inspection system 100 using optical measurements is provided according to this disclosure.

[0032] The electrode pressing condition inspection system 100 using optical measurement includes: A pair of pressure rollers 110 are located at the upper and lower parts based on the electrode conveying position. The drive unit drives a pair of pressure rollers 110. The first light source 120 is located on one side of the driving direction of the pair of pressing rollers and illuminates the pair of pressing rollers 110. The first sensor 130 is located on the opposite side of the driving direction of the pair of pressure rollers 110 and detects the light emitted from the first light source 120, and The control unit analyzes the surface information of the pair of pressure rollers 110 and the gap between the pair of pressure rollers 110 based on the information obtained by the first sensor 130. The first light source 120 and the first sensor 130 are respectively movable along the width direction of a pair of pressing rollers 110.

[0033] When the surface information of a pair of pressing rollers 110 is obtained from the first light source 120 and the first sensor 130, the pair of pressing rollers 110 are driven without supplying electrodes.

[0034] The first light source 120 and the first sensor 130 can move in pairs.

[0035] A pair of pressing rollers 110 are continuously driven, and a first light source 120 and a first sensor 130 can move from one edge to the other edge in the width direction of the pair of pressing rollers 110.

[0036] In this case, the driving speed of a pair of pressure rollers 110 can be 50 to 150 m / min, specifically 60 to 120 m / min, and more specifically 60 to 100 m / min.

[0037] Furthermore, considering the driving speed of the pair of pressure rollers 110, the moving speed of the first light source 120 and the first sensor 130 can be determined to be in the range of 10 m / min to 120 m / min. Specifically, the moving speed can be determined to be in the range of 20 m / min to 100 m / min, and more specifically, in the range of 20 m / min to 80 m / min.

[0038] Furthermore, when acquiring the surface information of a pair of pressing rollers 110, the surface information of a pair of pressing rollers 110 is acquired immediately. Therefore, taking into account the light intensity of the first light source 120 and the sensor size, the gap (g) between a pair of pressing rollers 110 can be from 50 μm to 300 μm, specifically from 70 μm to 250 μm, and more specifically from 100 μm to 250 μm.

[0039] Therefore, the surface information of a pair of pressure rollers 110 can be reliably obtained as a whole.

[0040] On the other hand, when acquiring surface information of the pair of pressure rollers 110, the information can be acquired through continuous driving and movement as described above. Alternatively, the first light source 120 and the first sensor 130 can start from one edge of the pair of pressure rollers 110 in the width direction and repeatedly move and stop at predetermined intervals until the other edge. When the first light source 120 and the first sensor 130 stop, the pair of pressure rollers 110 are driven to acquire surface information. The pair of pressure rollers 110 can also stop while the first light source 120 and the first sensor 130 are moving, thereby acquiring surface information. Any method is not limited as long as the surface information of the pair of pressure rollers can be acquired using a light source and a sensor.

[0041] The surface information of the pair of pressure rollers 110 obtained through this process is sent to the control unit and analyzed by the control unit. If there is a difference between the maximum and minimum values ​​of the gap between the pair of pressure rollers 110 in the surface information of the pair of pressure rollers 110 obtained from the first sensor that exceeds 10 μm—specifically, a portion exceeding 5 μm—the control unit can determine that the corresponding pressure roller is defective.

[0042] To explain in more detail, Figure 2 A flowchart of this suppression condition inspection system is shown.

[0043] Refer to together Figure 2 and Figure 1Before the pressing process, the first light source 120 and the first sensor 130 move along the width direction of a pair of pressing rollers 110 to acquire surface information of the pair of pressing rollers 110 and send it to the control unit. The control unit analyzes the surface information of the pair of pressing rollers 110. If there is a portion where the difference between the maximum and minimum values ​​of the gap between the pair of pressing rollers 110 exceeds 10 μm—specifically, exceeds 5 μm—then the pressing roller is determined to be defective and replaced. If there is no portion where the difference exceeds 10 μm—specifically, exceeds 5 μm—then the pressing process is executed.

[0044] For ease of understanding, Figure 3 and Figure 4 The results of obtaining surface information using the above-described method via a pressure roller used in an actual electrode manufacturing process are shown.

[0045] The experiment was conducted on a pair of pressure rollers with a width of 750 mm, and the gap between the two rollers was set to an average of 150 μm.

[0046] A laser is used as the first light source, and a CMOS sensor is used as the first sensor.

[0047] Set the drive speed of the pair of pressure rollers to 20 m / min.

[0048] Reference Figure 3 and Figure 4 , Figure 3 Rollers with a difference of 2 μm or less between the maximum and minimum gap between a pair of pressure rollers 110 are classified as normal rollers. Figure 4 Rollers with a difference of 10 μm between the maximum and minimum gap between a pair of pressure rollers 110 are classified as defective.

[0049] Therefore, the electrode pressing condition inspection system 100 according to this disclosure can prevent the deterioration of electrode quality that may occur due to defects in a pair of pressing rollers 110.

[0050] At the same time, continue to refer to Figure 2 The electrode pressing condition inspection system 100 of this disclosure illuminates and detects light at one edge of a pair of pressing rollers in the width direction, thereby further obtaining information about the gap between the pair of pressing rollers.

[0051] If the gap between a pair of pressing rollers obtained in this way differs from the initially set gap, adjust the gap and then measure it again. If there is no difference, continue with the electrode pressing process.

[0052] To illustrate the inspection system used to measure the gap between a pair of pressure rollers, Figure 5A schematic diagram of a pressing condition inspection system 200 according to yet another embodiment of the present disclosure is shown in the longitudinal direction, and Figure 6 A schematic diagram of the pressing condition inspection system 200 in the width direction is shown.

[0053] Reference Figure 5 and Figure 6 When measuring the gap g1 between a pair of pressing rollers, the measurement can be performed using a first light source 220 and a first sensor 230 located at one side edge. However, the inspection system has a first light source 220 and a first sensor 230 fixed to one side edge, and also includes a second light source 240 located on one side of the driving direction of the pair of pressing rollers 210 at the other side edge, and a second sensor 250 located on the other side of the driving direction of the pair of pressing rollers 210 and detecting the light emitted from the second light source 240, thereby enabling the acquisition of information about the gap g2 between the pair of pressing rollers 210.

[0054] The process of obtaining information about the gaps g1 and g2 between a pair of pressing rollers 210 can be performed in real time before and after the electrode is supplied. That is, it can be performed continuously during the electrode pressing process.

[0055] In this case, one side edge and the other side edge of a pair of pressing rollers 210 can be the parts through which the sheet electrode does not pass.

[0056] This is because the portion through which the sheet electrode passes is affected by factors such as the thickness of the active material layer of the sheet electrode, and therefore the substantial gap g1, g2 between a pair of pressing rollers 210 cannot remain constant.

[0057] Refer again Figure 2 The diagram illustrates a schematic flowchart of an electrode pressing condition inspection system 200, in which information about the gaps g1 and g2 between a pair of pressing rollers 210, acquired in this manner, is sent to a control unit. If the information differs from the initially set gap, the control unit corrects the gap between the pair of pressing rollers in real time; otherwise, the pressing process can be performed continuously.

[0058] Therefore, the electrode pressing condition inspection system according to this disclosure can produce electrodes of the same quality with consistent thickness.

[0059] Meanwhile, the first light source 120, 220 and the second light source 240 used in the electrode pressing condition inspection are not limited, as long as they are light sources with minimized divergence, and can be, for example, lasers, tungsten lamps or metal halide lamps, and more specifically, lasers.

[0060] In addition, the first light source 120, 220 and the second light source 240 may each include a collimating lens that remains horizontal during light illumination.

[0061] The first sensors 130 and 230 and the second sensor 250 are not limited, as long as they can receive light and display the distribution of the received light energy, and for example, they can be CMOS (Complementary Metal-Oxide-Semiconductor) sensors or CCD (Charge-Coupled Device) sensors. In this case, it is more advantageous with smaller resolution, and even more advantageous with smaller light-receiving pixel size.

[0062] Specifically, the resolution can be from 1 μm to 10 μm, more specifically from 3 μm to 8 μm, and even more specifically from 3 μm to 5 μm.

[0063] Furthermore, the first sensors 130 and 230 and the second sensor 250 can be line scan sensors with a width of 20 mm to 50 mm. Of course, this is proportional to the distance being measured and can be appropriately selected taking into account the divergence of the first light source 120 and 220 and the second light source 240.

[0064] Meanwhile, the first light source 120, 220, the second light source 240, the first sensor 130, 230 and the second sensor 250 can be located at a center interval of 100mm to 1000mm (l1, l2) with the pair of rollers 210 closest to each other, and specifically, they can be located at a interval of 200mm to 500mm.

[0065] If the distance is outside the aforementioned range and too close, there is a possibility of physical interference with the pair of pressing rollers, and if the distance is too far, the light will diverge or the pattern will become larger due to diffraction, and therefore the sensor cannot accurately measure the received light energy, which is not preferred.

[0066] Although preferred embodiments of the present disclosure have been shown and described above, the scope of the present disclosure is not limited thereto, and those skilled in the art can make many other variations and modifications to the embodiments using the basic principles of the invention as defined in the appended claims, which also fall within the spirit and scope of the invention.

[0067] [Industrial Applicability]

[0068] According to this disclosure, prior to the electrode pressing process, optical measurements can be used to obtain surface information about a pair of pressing rollers used in the pressing process. This allows for the pre-inspection and removal of defects in the pressing rollers, thereby enabling the use of a pair of pressing rollers with excellent surface properties. Therefore, it effectively improves the quality of the manufactured electrode.

[0069] Furthermore, during the pressing process, the gap between a pair of pressing rollers can be measured and adjusted in real time using optical measurements. Therefore, it effectively simplifies the pressing process and provides electrodes of consistent quality.

Claims

1. An electrode pressing condition inspection system using optical measurement, the electrode pressing condition inspection system comprising: A pair of pressure rollers, located at the upper and lower parts based on the electrode's conveying position. A drive unit that drives the pair of pressure rollers. A first light source is located on one side of the driving direction of the pair of pressing rollers and illuminates the pair of pressing rollers. A first sensor is located on the opposite side of the driving direction of the pair of pressure rollers and detects light emitted from the first light source; as well as The control unit analyzes the surface information of the pair of pressure rollers and the gap between the pair of pressure rollers based on the information obtained from the first sensor. The first light source and the first sensor are respectively capable of moving along the width direction of the pair of pressing rollers.

2. The electrode pressing condition inspection system according to claim 1, in, While acquiring surface information of the pair of pressing rollers from the first light source and the first sensor, the pair of pressing rollers are driven without supplying electrodes.

3. The electrode pressing condition inspection system according to claim 2, in, The pair of pressing rollers are continuously driven, and the first light source and the first sensor move from one edge to the other edge in the width direction of the pair of pressing rollers to obtain surface information of the pair of pressing rollers.

4. The electrode pressing condition inspection system according to claim 2 or 3, in, The driving speed of the pair of pressing rollers is 50 to 150 m / min.

5. The electrode pressing condition inspection system according to claim 1, in, The moving speed of the first light source and the first sensor is 10 to 120 m / min.

6. The electrode pressing condition inspection system according to claim 2 or 3, in, When obtaining the surface information of the pair of pressing rollers, the gap between the pair of pressing rollers is 50 μm to 300 μm.

7. The electrode pressing condition inspection system according to claim 1, in, If the surface information of the pair of pressure rollers obtained from the first sensor contains a portion where the difference between the maximum and minimum values ​​of the gap between the pair of pressure rollers exceeds 10 μm, then the control unit determines that the corresponding pressure roller is defective.

8. The electrode pressing condition inspection system according to claim 1, in, The first light source and the first sensor illuminate and detect light on one side edge of the pair of pressure rollers in the width direction, thereby obtaining information about the gap between the pair of pressure rollers.

9. The electrode pressing condition inspection system according to claim 8, It also includes a second light source and a second sensor. The second light source is located on one side of the driving direction of the pair of pressure rollers at the other side edge of the pair of pressure rollers, and the second sensor is located on the other side of the driving direction of the pair of pressure rollers and detects light emitted from the second light source, thereby obtaining information about the gap between the pair of pressure rollers.

10. The electrode pressing condition inspection system according to claim 8 or 9, in, The process of obtaining information about the gap between the pair of pressure rollers is performed in real time before and after the electrodes are supplied.

11. The electrode pressing condition inspection system according to claim 8 or 9, in, The edges of the pair of pressing rollers on one side and the other side are the portions through which the sheet electrode does not pass.

12. The electrode pressing condition inspection system according to claim 8, in, If the information obtained regarding the gap between the pair of pressure rollers differs from the initially set gap, the control unit corrects the gap between the pair of pressure rollers in real time.

13. The electrode pressing condition inspection system according to claim 1 or 9, in, The first light source and the second light source are a laser, a tungsten lamp, or a metal halide lamp, respectively.

14. The electrode pressing condition inspection system according to claim 1 or 9, in, The first light source and the second light source each include a collimating lens that remains horizontal during light illumination.

15. The electrode pressing condition inspection system according to claim 1 or 9, in, The first light source and the second light source are CMOS sensors or CCD sensors, respectively.

16. The electrode pressing condition inspection system according to claim 1 or 9, in, The first light source and the second light source are line scan sensors with a width of 20mm to 50mm.

17. The electrode pressing condition inspection system according to claim 1 or 9, in, The first light source, the second light source, the first sensor, and the second sensor are respectively located 100mm to 1000mm away from the center of the pair of rollers that are closest to each other.

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