Electrode rolling condition inspection system

Abstract

According to an embodiment of the present invention, an electrode rolling condition inspection system using optical measurement is provided, the electrode rolling condition inspection system comprising: a pair of rollers for rolling work, positioned above and below with respect to a transfer position of an electrode; a driving unit for driving the pair of rollers for rolling work; a first light source positioned at one side in a driving direction of the pair of rollers for rolling work and emitting light toward the pair of rollers for rolling work; a first sensor positioned at the other side in the driving direction of the pair of rollers for rolling work and detecting the light transmitted from the first light source; and a control unit for analyzing surface information of the pair of rollers for rolling work and a gap between the pair of rollers for rolling work from information obtained by the first sensor, wherein each of the first light source and the first sensor is movable in a width direction of the pair of rollers for rolling work.

Description

Electrode Rolling Condition Inspection System

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0150490 filed October 30, 2024 and Korean Patent Application No. 10-2025-0116767 filed August 21, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003] The present invention relates to an electrode rolling condition inspection system, and more specifically, to a system for inspecting electrode rolling conditions using optical measurements before and after electrode rolling.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), has become commonplace, the development of technologies in related fields is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0006] The above-mentioned lithium secondary battery primarily uses lithium-based oxide and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing, namely a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0007] The manufacturing process of such lithium secondary batteries is broadly divided into three stages: electrode process, assembly process, and formation process. The electrode process is further divided into active material mixing process, electrode coating process, rolling process, slitting process, and winding process. Among these, the rolling process is a process of compressing an electrode substrate to a desired thickness by passing it between a pair of high-temperature heated rolling rollers in order to reduce the thickness of the electrode substrate after the coating process to increase capacity density and increase adhesion between the electrode current collector and the electrode active material.

[0008] Since the above rolling process is performed by the above pair of rolling rollers, it is inevitably affected by rolling conditions such as the condition of the above pair of rolling rollers, the gap between them, and the roller driving speed.

[0009] Accordingly, research on methods to adjust the gap between the aforementioned pair of rolling rollers was actively conducted. Specifically, when replacing the rolling rollers, the position of the reference gap was recorded using a gap gauge of the reference thickness, and the gap was adjusted by changing the position of the roller based on the position of the reference gap during the rolling process. If the product specifications manufactured in this way did not match, the position of the roller was modified.

[0010] However, the above method had a problem in that it could only determine the relative position of the initial rolling roller during cold rolling, and thus could not reflect the gap reduction caused by hot rolling or roller expansion due to friction, and in this case, the rolling conditions had to be adjusted by referring to other indicators.

[0011] Accordingly, various studies are being conducted on methods to adjust the gap between the aforementioned pair of rolling rollers in real time.

[0012] Nevertheless, in reality, the specifications or quality of the electrode obtained after the above rolling process vary due to various causes as well as thickness variations caused by the gap between the pair of rollers, so there is a need to develop technology that can improve the quality of the manufactured electrode while maintaining it consistently.

[0013] The present invention aims to provide an electrode rolling condition inspection system that can improve and maintain the product quality of an electrode produced by inspecting the surface characteristics of a pair of rolling rollers used in the rolling process before the rolling process to eliminate defects in the pair of rolling rollers, and maintaining the gap between them at a constant level in real time during the actual rolling process.

[0014] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0015] According to one embodiment of the present invention,

[0016] As an electrode rolling condition inspection system using optical measurement,

[0017] A pair of rolling rollers positioned above and below the electrode transfer position,

[0018] A drive unit for driving the above pair of rolling rollers,

[0019] A first light source located on one side in the driving direction of the pair of rolling rollers and irradiating light toward the pair of rolling rollers,

[0020] A first sensor located on the other side in the driving direction of the above pair of rolling rollers and detecting light received from the first light source, and

[0021] It includes a control unit that analyzes surface information of the pair of rolling rollers and the gap between the pair of rolling rollers from information obtained from the first sensor, and

[0022] An electrode rolling condition inspection system is provided in which the first light source and the first sensor are each movable in the width direction of the pair of rolling rollers.

[0023] FIG. 1 is a perspective view of a rolling condition inspection system according to one embodiment of the present invention.

[0024] FIG. 2 is a schematic flowchart of a rolling condition inspection system according to one embodiment of the present invention.

[0025] Figure 3 is a graph of surface information of a pair of rolling rollers identified as normal.

[0026] Figure 4 is a graph of surface information of a pair of rolling rollers identified as defective.

[0027] FIG. 5 is a schematic diagram of the longitudinal side of a rolling condition inspection system according to another embodiment of the present invention.

[0028] FIG. 6 is a schematic diagram in the width direction of a rolling condition inspection system according to another embodiment of the present invention.

[0029] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0030] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0031] Meanwhile, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0032] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0033] Furthermore, throughout the specification, “one side” and “the other side” refer to both sides separated by a specific standard. Additionally, “edge portion” refers to the end portion of the part.

[0034] Furthermore, in the specification, “width” refers to the length in the direction penetrating the circle when the rolling roller is cut so that its cross-section is circular. The “width” in the sensor also refers to the length in the said direction. Conversely, “length” refers to the length from one side of the rolling roller to the other when viewed from the direction in which the electrode is inserted.

[0035]

[0036] FIG. 1 shows a perspective view of an electrode rolling condition inspection system (100) according to one embodiment of the present invention.

[0037] Referring to FIG. 1, an electrode rolling condition inspection system (100) using optical measurement according to the present invention is provided.

[0038] The electrode rolling condition inspection system (100) using optical measurement is,

[0039] A pair of rolling rollers (110) positioned above and below the electrode transfer position,

[0040] A driving unit that drives a pair of rolling rollers (110),

[0041] A first light source (120) located on one side in the driving direction of a pair of rolling rollers (110) and irradiating light toward a pair of rolling rollers (110),

[0042] A first sensor (130) located on the other side in the driving direction of a pair of rolling rollers (110) and detecting light received from a first light source (120), and

[0043] It includes a control unit that analyzes surface information of a pair of rolling rollers (110) and the gap between a pair of rolling rollers (110) from information obtained from a first sensor (120), and

[0044] The first light source (120) and the first sensor (130) are each characterized by being movable in the width direction of a pair of rolling rollers (110).

[0045] When obtaining surface information of a pair of rolling rollers (110) from a first light source (120) and a first sensor (130), the pair of rolling rollers (110) may be driven in a state where the electrodes are not supplied.

[0046] The first light source (120) and the first sensor (130) can move as a pair.

[0047] A pair of rolling rollers (110) can be driven continuously, and a first light source (120) and a first sensor (130) can be moved from one edge in the width direction of the pair of rolling rollers (110) to the other edge.

[0048] At this time, the driving speed of a pair of rolling rollers (110) may be 50 to 150 m / min, more specifically 60 m / min to 120 m / min, and more specifically 60 m / min to 100 m / min.

[0049] In addition, the movement speed of the first light source (120) and the first sensor (130) can be determined in the range of 10 m / min to 120 m / min by taking into account the driving speed of a pair of rolling rollers (110). More specifically, it can be determined 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.

[0050] Additionally, when obtaining surface information of a pair of rolling rollers (110), since the surface information of a pair of rolling rollers (110) is obtained at once, considering the amount of light from the first light source (120) and the sensor size, the gap (g) between a pair of rolling rollers (110) may be 50㎛ to 300㎛, more specifically 70㎛ to 250㎛, and even more specifically 100㎛ to 250㎛.

[0051] From this, surface information of a pair of rolling rollers (110) can be reliably obtained.

[0052] Meanwhile, surface information of a pair of rolling rollers (110) can be obtained by driving and moving continuously as described above, but alternatively, the first light source (120) and the first sensor (130) may repeatedly move and stop at a predetermined interval starting from one edge portion in the width direction of the pair of rolling rollers (110) to the other edge portion, and when the first light source (120) and the first sensor (130) stop, the pair of rolling rollers (110) drive to obtain surface information, and when the first light source (120) and the first sensor (130) move, the pair of rolling rollers (110) stop while obtaining surface information. Any method is not limited as long as it is a form in which surface information of a pair of rolling rollers can be obtained using a light source and a sensor.

[0053] Surface information of a pair of rolling rollers (110) obtained through such a process is transmitted to and analyzed by the control unit. If, in the surface information of a pair of rolling rollers (110) obtained from the first sensor, there is a part where the difference between the maximum and minimum gaps between the pair of rolling rollers (110) exceeds 10㎛, specifically 5㎛, the control unit may determine that the corresponding rolling roller is defective.

[0054] To explain in more detail, Figure 2 shows a flowchart of such a rolling condition inspection system.

[0055] Referring to FIG. 2 together with FIG. 1, before the rolling process, a first light source (120) and a first sensor (130) move in the width direction of a pair of rolling rollers (110) to obtain surface information of a pair of rolling rollers (110) and send it to a control unit. The control unit analyzes the surface information of the pair of rolling rollers (110) based on the analysis. If there is a part where the difference between the maximum and minimum gaps between the pair of rolling rollers (110) exceeds 10㎛, specifically 5㎛, then the rolling roller is determined to be defective and replaced. If there is no part where the difference exceeds 10㎛, specifically 5㎛, then the rolling process is performed.

[0056] Figures 3 and 4 illustrate the results of obtaining surface information in the same manner as above for a rolling roller used in an actual electrode manufacturing process for ease of understanding.

[0057] The experiment was conducted on a pair of rolling rollers with a width of 750 mm, and the gap between the pair of rolling rollers was set to an average of 150 μm.

[0058] The first light source uses a laser, and the first sensor uses a CMOS sensor.

[0059] The driving speed of a pair of rolling rollers was set to 20 m / min.

[0060] Referring to FIG. 3, FIG. 3 is classified as a normal roll with a maximum-minimum gap difference between a pair of rolling rollers (110) of 2 μm or less, and FIG. 4 is classified as a defective roll with a maximum-minimum gap difference between a pair of rolling rollers (110) of 10 μm.

[0061] Thus, the electrode rolling condition inspection system (100) according to the present invention can prevent electrode quality degradation that may occur due to defects in a pair of rolling rollers (110).

[0062] Meanwhile, referring to FIG. 2, the first light source and the first sensor of the electrode rolling condition inspection system (100) according to the present invention can further obtain information about the gap between the pair of rolling rollers by irradiating and detecting the light at one edge portion in the width direction of the pair of rolling rollers.

[0063] If the gap between the pair of rolling rollers obtained in this way differs from the initially set gap, the gap is adjusted and the gap is measured again; if there is no difference, the electrode rolling process is continued.

[0064] To illustrate an inspection system for measuring the gap between such a pair of rolling rollers, FIG. 5 shows a schematic diagram in the longitudinal direction of a rolling condition inspection system (200) according to another embodiment of the present invention, and FIG. 6 shows a schematic diagram in the width direction of a rolling condition inspection system (200).

[0065] Referring to FIGS. 5 and 6, when measuring the gap (g1) of the pair of rolling rollers, it is possible to measure using a first light source (220) and a first sensor (230) at one edge, but furthermore, the first light source (220) and the first sensor (230) are fixed at one edge, and a second light source (240) is located at one side in the driving direction of the pair of rolling rollers (210) at the other edge of the pair of rolling rollers (210) and irradiates light toward the pair of rolling rollers (210), and a second sensor (250) is located at the other side in the driving direction of the pair of rolling rollers (210) and detects light received from the second light source (240), thereby additionally obtaining information about the gap (g2) between the pair of rolling rollers (210).

[0066] The process of obtaining information about the gap (g1, g2) between these pair of rolling rollers (210) can be performed in real time before and after the supply of the electrode. That is, it can be performed continuously during the electrode rolling process.

[0067] At this time, one edge portion and the other edge portion of a pair of rolling rollers (210) may be a portion through which the sheet-type electrode does not pass.

[0068] This is because the actual gap (g1, g2) of a pair of rolling rollers (210) cannot be obtained consistently in the part through which the sheet-type electrode passes, as it is affected by the thickness of the active material layer of the sheet-type electrode.

[0069] Referring again to FIG. 2, which illustrates a flow diagram of the electrode rolling condition inspection system (200) of the present invention, information regarding the gap (g1, g2) between a pair of rolling rollers (210) obtained in this manner is transmitted to the control unit, and if the information differs from the initially set gap, the control unit corrects the gap between the pair of rolling rollers in real time, and if not, can continuously perform the rolling process.

[0070] Thus, the electrode rolling condition inspection system according to the present invention can produce electrodes of the same quality with a constant thickness.

[0071] Meanwhile, the first light source (120, 220) and the second light source (240) used for the electrode rolling condition inspection are not limited to light sources that minimize emission, and may be, for example, a laser, a tungsten lamp, or a metal halide lamp, and specifically, a laser.

[0072] Furthermore, the first light source (120, 220) and the second light source (240) may each further include a collimator lens that maintains a horizontal position when irradiating light.

[0073] The first sensor (130) and the second sensor (230, 250) are not limited to those capable of receiving light and displaying a light energy distribution, but, for example, they may be a CMOS (Complementary Metal Oxide Semiconductor) sensor or a CCD (Charge-Coupled Device) sensor, and in this case, it is advantageous for the resolution to be smaller and for the light receiving pixel size to be smaller.

[0074] Specifically, the resolution may be 1 µm to 10 µm, more specifically 3 µm to 8 µm, and even more specifically 3 µm to 5 µm.

[0075] Additionally, the first sensor (130, 230) and the second sensor (250) may, in detail, be line scan sensors with a width of 20 mm to 50 mm. Of course, this may be appropriately selected in proportion to the measured distance and considering the degree of emission of the first light source (120, 220) and the second light source (240).

[0076] Meanwhile, the first light source (120, 220), the second light source (240), the first sensor (130, 230), and the second sensor (250) may each be positioned at a distance of 100mm to 1000mm (l1, l2) from the center closest to the pair of rolling rolls (210), and more specifically, at a distance of 200mm to 500mm.

[0077] If it is too close outside the above range, there may be physical interference with the pair of rolling rollers, and if it is too far, light may be emitted or the pattern may enlarge due to diffraction, which is undesirable as it causes a problem where the sensor cannot accurately measure the received light energy.

[0078]

[0079] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0080] According to the present invention, by obtaining surface information of a pair of rolling rollers used in the rolling process using optical measurement before performing the rolling process on the electrode, defects in the rolling rollers can be inspected in advance and removed, thereby enabling the use of a pair of rolling rollers with excellent surface characteristics, which has the effect of improving the quality of the manufactured electrode.

[0081] In addition, during the rolling process, the gap between the pair of rolling rollers can be measured in real time and adjusted using the optical measurement, which has the effect of simplifying the rolling process and providing electrodes of consistent quality.

Claims

1. As an electrode rolling condition inspection system using optical measurement, A pair of rolling rollers positioned above and below the electrode transfer position, A drive unit for driving the above pair of rolling rollers, A first light source located on one side in the driving direction of the pair of rolling rollers and irradiating light toward the pair of rolling rollers, A first sensor located on the other side in the driving direction of the above pair of rolling rollers and detecting light received from the first light source, and It includes a control unit that analyzes surface information of the pair of rolling rollers and the gap between the pair of rolling rollers from information obtained from the first sensor, and The first light source and the first sensor are each an electrode rolling condition inspection system capable of moving in the width direction of the pair of rolling rollers.

2. In Paragraph 1, An electrode rolling condition inspection system in which, when obtaining surface information of the pair of rolling rollers from the first light source and the first sensor, the pair of rolling rollers is driven in a state where the electrode is not supplied.

3. In Paragraph 2, An electrode rolling condition inspection system in which the above pair of rolling rollers are driven continuously, and the first light source and the first sensor move from one edge portion in the width direction of the pair of rolling rollers to the other edge portion, and obtain surface information of the pair of rolling rollers.

4. In Paragraph 2 or 3, An electrode rolling condition inspection system in which the driving speed of the above pair of rolling rollers is 50 to 150 m / min.

5. In Paragraph 1, An electrode rolling condition inspection system in which the moving speed of the first light source and the first sensor is 10 to 120 m / min.

6. In Paragraph 2 or 3, An electrode rolling condition inspection system in which, when obtaining surface information of the pair of rolling rollers, the gap between the pair of rolling rollers is 50㎛ to 300㎛.

7. In Paragraph 1, The above control unit is an electrode rolling condition inspection system that determines a rolling roller as defective if, in the surface information of the pair of rolling rollers obtained from the first sensor, there exists a part where the difference between the maximum and minimum gaps between the pair of rolling rollers (110) exceeds 10 μm.

8. In Paragraph 1, The first light source and the first sensor are an electrode rolling condition inspection system that obtains information about the gap between the pair of rolling rollers by irradiating and detecting the light at one edge portion in the width direction of the pair of rolling rollers.

9. In Paragraph 8, An electrode rolling condition inspection system for obtaining information about the gap between the pair of rolling rollers, further comprising: a second light source located on one side in the driving direction of the pair of rolling rollers at the other edge portion of the pair of rolling rollers and irradiating light toward the pair of rolling rollers; and a second sensor located on the other side in the driving direction of the pair of rolling rollers and detecting light received from the second light source.

10. In Paragraph 8 or 9, An electrode rolling condition inspection system in which the process of obtaining information about the gap between the above-mentioned pair of rolling rollers is performed in real time before and after the supply of electrodes.

11. In Paragraph 8 or 9, An electrode rolling condition inspection system in which one edge portion and the other edge portion of the above pair of rolling rollers are parts through which the sheet-type electrode does not pass.

12. In Paragraph 8, If the information regarding the gap between the pair of rolling rollers obtained above differs from the initially set gap, the control unit is an electrode rolling condition inspection system that corrects the gap between the pair of rolling rollers in real time.

13. In Paragraph 1 or Paragraph 9, An electrode rolling condition inspection system in which the first light source and the second light source are each a laser, a tungsten lamp, or a metal halide lamp.

14. In Paragraph 1 or Paragraph 9, An electrode rolling condition inspection system comprising a first light source and a second light source, each including a collimator lens that maintains horizontal alignment during light irradiation.

15. In Paragraph 1 or Paragraph 9, An electrode rolling condition inspection system in which the first sensor and the second sensor are each a CMOS sensor or a CCD sensor.

16. In Paragraph 1 or Paragraph 9, The electrode rolling condition inspection system, wherein the first sensor and the second sensor are line scan sensors having a width of 20 mm to 50 mm.

17. In Paragraph 1 or Paragraph 9, An electrode rolling condition inspection system in which the first light source, the second light source, the first sensor, and the second sensor are each positioned at a distance of 100 mm to 1000 mm from the center where the pair of rolling rolls are closest.

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